Monday, June 24 Tuesday, June 25 Wednesday, June 26 Thursday, June 27
9:00 ‑ 10:30 am TUT1: Tutorials 1
TUT2: Tutorials 2
TUT3: Tutorials 3
10:30 am ‑ 12:00 pm IMET1: IoT, M2M and Enabling Technologies 1
SS01-1: Recent Issues in Mobile and Wireless Networks
SS02-1: Social Network Analysis and Mining
  CR1: Cognitive Radio 1
RRM1: Radio Resource Management 1
SS07: Technology Enablers for Future Ultra Dense Wireless Networks
MULTI: Multimedia
PLCCM1: Physical layer, channel coding and modulation 1
12:00 ‑ 1:00 pm        
1:00 ‑ 2:30 pm IMET2: IoT, M2M and Enabling Technologies 2
SS01-2: Recent Issues in Mobile and Wireless Networks
SS02-2: Social Network Analysis and Mining
SS06-1: Next Generation Network Security 1 CR2: Cognitive Radio 2
RRM2: Radio Resource Management 2
SS08: Performance, Measurement, Evaluation and Security of Wireless and Mobile Networks
IP1: Invited papers
PLCCM2: Physical layer, channel coding and modulation 2
2:30 ‑ 4:00 pm IMET3: IoT, M2M and Enabling Technologies 3
S11-1: M2M applications - Trends & Challenges
SS03: Inference in Wireless Sensor Networks
SS04: Information Theoretic Physical Layer Security (Invited Papers)
NMP1: Network Measurement and Performance 1
RRM3: Radio Resource Management 3
SS09-1: Recent Advances in Spectrum Measurements and Modelling towards Flexible Spectrum Usage
SS10-1: Green Cognitive Radio Access Networks
IP2: Invited papers
PLCCM3: Physical layer, channel coding and modulation 3
SS12-1: Virtual Networks and Cloud Computing
4:00 ‑ 4:30 pm        
4:30 ‑ 6:00 pm MIMO: MIMO
S11-2: M2M applications - Trends & Challenges
SS05: Layered Security over Radio Networks (SecNet) (Invited Papers)
SS06-2: Next Generation Network Security 2
  AS: Applications and Services
NMP2: Network Measurement and Performance 2
SS09-2: Recent Advances in Spectrum Measurements and Modelling towards Flexible Spectrum Usage
SS10-2: Green Cognitive Radio Access Networks
LOCMOB: Localization and Mobility
SS12-2: Virtual Networks and Cloud Computing
SS14: Cooperative Wireless Systems
6:00 ‑ 7:00 pm        

Monday, June 24

9:00 AM - 7:00 PM (America/New_York)

TUT1: Tutorials 1go to top

9:00 Distributed Mobility Management for Future Internet
H Anthony Chan (Huawei Technologies, USA)
The cellular networks, which are currently serving 5 billion cellular phones and mobile devices globally, have employed centralized control with different network functions arranged in a hierarchy. Standardization of Internet mobility management in the Internet Engineering Task Force (IETF) has been primarily in centralized mobility management including Mobile IPv6 (MIPv6) and its extensions, and the deployments have primarily been in a centralized manner for the hierarchical cellular networks. Yet there are already numerous variants and extensions of MIPv6 including Proxy Mobile IPv6 (PMIPv6), Hierarchical MIPv6 (HMIPv6), and Network Mobility (NEMO), which have been developed over the years owing to the different needs that are found afterwards. Deployment of Internet mobility mechanisms can then become complicated, especially when interoperability with different deployments is an issue. The Internet has employed distributed control functions and is more flattened, i.e., less hierarchical. As the cellular networks converge with the Internet and may become more flattened, the needed mobility management functions are expected to be distributed rather than centralized. Despite the large amount of standards work in Internet mobility in IETF primarily with centralized mobility, the deployment in the Internet is still slow. Such a fundamental change to distributed mobility is needed in the mobile Internet. Mobility management with centralized mobility anchoring in existing hierarchical mobile networks is quite prone to suboptimal routing and issues related to scalability. Centralized functions present a single point of failure, and inevitably introduce longer delays and higher signaling loads for network operations related to mobility management. To make matters worse, there are numerous variants of Mobile IP in addition to other protocols standardized outside the IETF, making it much more difficult to create economical and interoperable solutions. The existing mobility management standards in IETF, the issues of mobility management for the future mobile Internet, the trend of the mobile Internet and the proposed distributed mobility at IETF are explained.
2:00 Dynamic Spectrum Access: A Survey
Subir Das (Applied Communication Sciences, USA)
Radio Spectrum in every country is tightly regulated by government agencies and is assigned to service providers to deploy transmitters and receivers that hold the license for specific geographical regions. A small portion of the spectrum however is allowed for use by unlicensed users but with restriction to transmit power so that it does not cause harmful interference with the licensed users. The demand for using radio spectrum is ever increasing due to the flexibility and mobility of last mile wireless access that is benefiting the consumers and businesses. Regulators are always finding ways to release the new spectrum and spur the technology innovation that will ultimately impact to the social and economic developments of a country. On the other hand, the inefficiency in the spectrum usage and the technology that can be deployed are creating the spectrum shortage and making the overall spectrum allocation harder for regulators. Due to these reasons, several regulators have conducted the studies on how the allocated spectrum are being used today. US Federal Communications Commission (FCC) study shows that temporal and geographical variations in the utilization of assigned spectrum range from 15% to 85%. In recent years, academic and industry researchers have proposed the Dynamic Spectrum Access, a way to solve the spectrum inefficiency problem. The basic concept is to first identify the radio spectrum that is assigned to licensed users (a.k.a., primary users) but are not used at a specific time and location, commonly known as White Space , and then allow the additional users (a.k.a., secondary users) to use that spectrum without harmful interference with the licensed users. This opportunistic access imposes several research challenges, some of which are solved and others are being investigated.

TUT2: Tutorials 2go to top

9:00 Context Aware Computing for Next Generation Wireless Networks
Prithiviraj Venkatapathy (Pondicherry Engineering College, India)
When humans converse with each other there are in a position to implicitly use their location information or context to increase the conversational bandwidth. Unfortunately this idea does not translate well to humans interacting with computers but by improving the computer access to context one could increase the richness of communication within human computer interaction and enable it to provide more useful, computational services.
2:00 ZigBee Wireless Sensor and Control Network
Ata Elahi (Souther Connecticut State University, USA)
Wireless Sensor and Control Networks are quickly becoming an integral part of the automation process within chemical plants, refineries, and commercial buildings. As a result, the market for wireless sensor and control networks is rapidly growing. Furthermore, according to a new market research report, it will be a $3.8 billion industry by the year 2017. To accommodate this burgeoning technology, numerous standards are being developed for wireless sensor and control networking such as SP100.11(Wireless Systems for Automation) by the Industrial Standard for Automation (ISA), Wireless HART (Highway Addressable Remote Transducer) by the HART organization, IPv6 over Low Rate Wireless Personnel Network (6LoWPAN) by IETF (the Internet Engineering Task Force) and ZigBee by the ZigBee alliance. Applications of ZigBee Wireless Sensor and Control Networks are: Commercial Building Automation, Home automation, Industrial and process automation, Energy and utility automation, Health Care, Remote Control.

TUT3: Tutorials 3go to top

9:00 Application of Short Erasure Correcting Codes for Opportunistic Spectrum Access and cognitive radio MAC
Muhammad Moazam Azeem (Orange Labs, France)
Cognitive Radio (CR) aims to dramatically improve spectrum access, capacity and link performance, the main driver being the traffic surge due to new communication devices (smartphones) and the resulting spectrum shortage. The inefficient usage of some large parts of licensed spectrum has made the situation even worse. Some flexible schemes have been designed, aiming to a dynamic sharing of the spectrum. One of these access schemes has the form of a primary/secondary scenario, where a secondary user (SU) accesses the channel without coordination with PU while it is not active and it is called opportunistic spectrum access (OSA). No coordination means that SU performs sensing to detect the possible PU activity. However, sensing is not perfect and exhibits two kinds of impairments: False alarms and non-detection. While the former is a cause of inefficiency of the secondary reuse of the channel because of missed opportunities, the latter is a cause of harmful interference to the primary user.
2:00 Low Overhead Communication Mechanism for Constrained Sensor Gateway in IoT
Soma Bandyopadhyay (TATA Consultancy Services, India)
Today's world is experiencing a speedy progress towards "Internet of Everything" and hence a smart-world. Sensing environment, interpreting sensor data, analyzing aggregated sensed data from different parts of the environment, making suitable decision, and accordingly taking actions are various steps involved in building smart-world. Important actors are undoubtedly sensors and sensor- gateways, and the communicated sensor data. But sensors and sensor-gateways have limitations in terms of their bandwidth and energy required for communication. In this perspective reduction of communication overhead in terms of bandwidth and energy usage is extremely necessary. Current tutorial presents low overhead application protocols with reliability in the context of IoT (Internet of Things). The objective of this tutorial is to present a best choice of low overhead application protocol for transmitting sensor data over the Internet, addressing the limitations of energy and bandwidth usage by the constrained sensors/sensor-gateways.

Tuesday, June 25

10:30 AM - 12:00 PM (America/New_York)

IMET1: IoT, M2M and Enabling Technologies 1go to top

Room: Central Park
Chair: Luis Sanchez (University of Cantabria, Spain)
10:30 Relay Access Point Congestion Control Scheme using Buffer Control for Wireless LAN Mesh Networks
Jun Komatsu (Chiba University, Japan); Shiro Sakata (Chiba University, Japan); Nobuyoshi Komuro (Chiba University, Japan); Tutomu Murase (NEC Corporation, Japan); Shigeo Shioda (Chiba University, Japan)
In wireless LAN mesh networks, relay access points (APs) tend to cause buffer overflow due to the decrease in transmission opportunities. This paper proposes a novel congestion control scheme for legacy stations (STAs) accommodated by edge APs. By applying Receiving-Opportunity Control (ROC) to legacy STAs, the proposed scheme can reduce the amount of buffer overflow in mesh access points (MAPs). The proposed scheme is employed depending on the number of MAC frames in the communication buffers. The simulation results show that the proposed scheme achieves improvement in the end-to-end throughput, latency and delivery ratio.
10:52 A Histogram-based Cascade Detector for Radio Tomographic Localization
Yang Li (Beijing University of Posts and Telecommunications, P.R. China); Yuqian Pan (Beijing Institute of Spacecraft System Engineering, P.R. China); Dongwei Bai (Beijing Institute of Spacecraft System Engineering, P.R. China); Hang Liu (Beijing University of Posts and Telecommunications, P.R. China); Bo Yang (Beijing University of Posts and Telecommunications, P.R. China)
Radio tomographic localization (RTL) is an emerging technology for estimating the position of objects by analyzing received signal strength (RSS) variation in wireless sensor networks (WSNs). This method can localize targets which do not need to carry any electronic devices or tags, so that it is of great importance in applications such as surveillance, rescue operations and smart-buildings. This paper introduces a fast and effective RTL method. In this method, we propose a histogram-based target feature and a cascaded detection strategy. This method can localize an unknown number of objects with high accuracy in different environments, and the computational complexity is low enough to be used for real-time systems. First, we present a series of single-link experiments to demonstrate the proposed target feature. Then a cascaded detection process is introduced to locate an unknown number of targets while reducing much computation. To evaluate the proposed RTL method, experiments including both outdoor and indoor environment are conducted and the performance is carefully demonstrated.
11:15 Applying Background Learning Algorithms to Radio Tomographic Imaging
Aidong Men (Beijing University of Posts and Telecommunications, P.R. China); Jianfei Xue (Beijing University of Posts and Telecommunications, P.R. China); Junyan Liu (Beijing University of Posts and Telecommunications, P.R. China); Tianming Xu (Beijing University of Posts and Telecommunications, P.R. China); Yi Zheng (Beijing University of Posts and Telecommunications, P.R. China)
Radio tomographic imaging (RTI) is an emerging technique which obtains images of passive targets (i.e., not carrying electronic device) within a wireless sensor network using received signal strength (RSS). One major problem that restricts the application of RTI is the difficulty to model the variations of RSS measurements caused by moving targets in different multipath environments. This paper proposes to apply background learning algorithm to RTI system to model variations. Compared with previous RSS-based device free localization methods, the proposed method achieves higher accuracy in multi-target and time-varying environment without offline training. Firstly, two fundamental background learning algorithms, mixture of gaussians and kernel density estimation, are introduced to calculate the probabilities of links being affected by targets using RSS measurement. Then, Tikhonov regularization is applied to the reconstruction of images using the probabilities. Experimental results show that the proposed approach achieves high accuracy and increases the RSS-network capacity considerably.
11:37 Centralized Scheduling of In-band Device-to-Device Communication Underlaying Cellular Networks
Junyi Feng (Telecom Bretagne, France); Thomas Derham (Orange Labs, Japan); Samir Saoudi (Telecom-Bretagne, France)
In this article, scheduling method of in-band Device-to-Device (D2D) communication underlaying cellular networks is studied.We address a single cell scenario in which several UEs have buffered data for local UEs in the same cell, and they are considered as potential D2D pairs.We propose an interference coordinated scheme, in which eNB selects D2D or UL/DL mode for each potential D2D pair, and allocates resources and power to D2D transmissions. The proposed scheduling method put no constraint on D2D distance or D2D number in a cell. The results show that spectral efficiency gain and overall user throughput are substantially increased with proper central coordination.

SS01-1: Recent Issues in Mobile and Wireless Networksgo to top

Room: Fairmount Park
Chairs: Der Jiunn Deng (National Changhua University of Education, Taiwan), Chih-Cheng Tseng (National Ilan University, Taiwan)
10:30 Interference Mitigation in Two-Tier Femtocell Networks
Chih-Cheng Tseng (National Ilan University, Taiwan); Yi-Fan Tsai (National Ilan University, Taiwan); Ching-Shun Peng (National Ilan University, Taiwan); Fang-Chang Kuo (National Ilan University, Taiwan); Hwang-Cheng Wang (National Ilan University, Taiwan); Kuo-Chang Ting (Minghsin University of Science and Technology, Hsinchu, Taiwan)
With the rapid growth of wireless communications, the requirements of the service quality and the data transmission rate are gradually increased. Although the requirements can be met by building macrocell base stations (MBSs), it introduces high implementation costs and other issues. Hence, the operators can not improve the coverage and service quality shortly. However, as the technologies of femtocells are proposed, femto base station (FBS) can be rapidly installed to solve the problems mentioned above with a relatively low equipment expenses and implementation costs. Although femtocells provide many benefits, such as the improvement of indoor signal quality and transmission rate, it also introduces some issues, such as the problems of cross-tier interference and vertical handoff mechanism and so on. Therefore, we investigate the problem of cross-layer interference and propose a power control scheme to adjust FUE's transmission power to mitigate the cross-tier interference in a two-tier cellular network.
10:52 Run-time Estimation of the Number of Un-identified Tags in RFID Systems
Hui-Hsin Chin (National Changhua University of Education, Taiwan); Der-Jiunn Deng (National Changhua University of Education, Taiwan); Chun-Cheng Lin (National Chiao Tung University, Taiwan)
Current medium access control (MAC) protocols for wireless sensor networks (WSNs) do not support prioritized channel access and often suffer from varying degrees of starvation and fairness problems. That is, with a little bad luck, a sensor node might have to wait arbitrarily long to send its frame, and thus results in the invisibility of some sensed area. In this paper we introduce a simple, but yet well performing starvation-free backoff scheme based on sensor MAC (S-MAC) protocol for WSNs. The proposed scheme allows a sensor node to adjust its backoff window size according to its re-transmission times. An analytical analysis is carried out to study the saturation throughput of proposed scheme under backlogged conditions. In addition to the theoretical analysis, simulations were also conducted to analyze the proposed scheme and the results show that our scheme can effectively alleviate the starvation and fairness problem and achieve better performance in high density WSNs.
11:15 Bandwidth Allocation of Contingency Cellular Network
Jyh-Shyan Huang (National Chengchi University, Taiwan); Yun-Ting Wu (National Chengchi University, Taiwan); Yao-Nan Lien (National Chengchi University, Taiwan)
When stricken by a large-scale disaster, the efficiency of disaster response operation is very critical to life saving. We propose to build a contingency cellular network (CCN) to support emergency communication in large scale natural disasters by connecting disconnected base stations. This research addresses the bandwidth allocation problem. The advance of mobile communication technologies has brought great convenience to users. Cellular phone becomes the first communication tool most people would use in emergency. However, cellular networks were usually crashed in earthquake, typhoons or other natural disasters due to power outage or backhaul breakage. Unfortunately, the efficiency of communication system is a critical factor to the success of disaster response operation such as resource allocation as well as coordination of rescue and relief operations. We designed a contingency cellular network (CCN) by connecting physically intact but service-disrupted base stations together with wireless links. As the bandwidth resource in CCN is limited, a smart bandwidth allocation to facilitate prioritized bandwidth sharing will maximize the contribution of CCN to the disaster response operation. We model the CCN Bandwidth Allocation Problem into a Nested 0-1 Knapsack Problem aiming to maximize disaster response operation efficiency. The problem is proven to be NP Hard. We also design an efficient heuristic algorithm to solve the problem when it is needed in urgent.
11:37 Performance Guaranteed Statistical Traffic Control in Cognitive Cellular Networks
Shao-Yu Lien (National Formosa University, Taiwan); Shin-Ming Cheng (National Taiwan University of Science and Technology, Taiwan)
To deploy cellular networks, crowded spectrum leads to compact arrangements of frequency bands among wireless/cellular networks resulting in unsolvable interference in Layer 1. For circumstances without centralized coordination, the cognitive radio (CR) as the most promising technology for interference avoidance, however, can only be supported by cellular networks in limited functionalities of interference detection and opportunistic channel access under the concerns of unreliability in operations and potential system overheads, which may harm the most important quality-of-service (QoS) guarantees. Considering the power of multicell cooperated multipath (MCM) technology on enhancing QoS, the critical challenge lies in an effective control of packet transmissions, radio resources, and call admission from Layer 1 to Layer 3. To merge merits of CR and MCM, we propose the statistical traffic control (STC), under which, each packet of constant bit rate (CBR) and variable bit rate (VBR) sources is transmitted through all available paths in MCM. Deriving sufficient conditions for QoS guarantees, the time domain radio resource is optimized. By evaluating performance on voice and video transmissions, we demonstrate the effectiveness of the STC to practice cognitive cellular networks.

SS02-1: Social Network Analysis and Mininggo to top

Room: Monticello Park
Chair: Jun Guo (BUPT, P.R. China)
10:30 FLAS:Traffic analysis of emerging applications on Mobile Internet using cloud computing tools
Yuanyuan Qiao (Beijing University of Posts and Telecommunications, P.R. China); Zhenming Lei (University of Posts and Telecommunications, P.R. China); Yang Jie (Beijing University of Posts and Telecommunications, P.R. China); Gang Cheng (Microsoft Corporation, P.R. China)
Recently, Mobile Internet became the most popular network in China. There are a lot of emerging applications growing with the development of Mobile Internet. This paper illustrate the design of a Hadoop-based tool, Flow Logs Analysis System (FLAS), for analysis these applications. FLAS can storage, process and compute the massive Mobile Internet flow logs efficiently. Furthermore, the traffic of leading Micro-blog(LM-blog) and e-business operators(E-shop) was analyzed using FLAS based on the flow logs collected with a passive network monitoring equipment placed on a large Internet Service Provider (ISP) in Southern China. And the distribution features of LM-blog and E-shop traffic, as well as the flow duration and the relationship between packets and bytes were investigated.
10:52 Using Traffic Flow Data to Analyze the Large-scale Social Networking Behavior
Ke Yu (Beijing University of Posts and Telecommunications, Beijing, P.R. China); Jiaxi Di (Beijing University of Posts and Telecommunications, P.R. China); Xinyu Zhang (Beijing University of Posts and Telecommunications, P.R. China); Xaiofei Wu (Beijing University of Posts and Telecommunications, P.R. China)
The rapid developments in Internet are reshaping many of our routine daily activities, ranging from how we communicate with our friends to how we shop. Understanding the human behaviors and dynamics in such a large-scale social network is essential for better system design, service provisioning, and network management. In this paper, based on real traffic flow data collected from operational networks of Internet Service Provider, the flow graph is constructed to model the interactions among users. We focus on three of the most popular interactive applications on Internet, QQ, Skype and MSN, and investigate the statistical characteristics of the flow graphs. The degree distribution and strength distribution of the flow graphs are analyzed, and the community structure is also discussed. Comparative analysis results show different characteristics of the three interactive applications, which imply the heterogeneous user behaviors on Internet.
11:15 Using Traffic Flow Data to Analyze the Large-scale Social Networking Behavior
Ke Yu (Beijing University of Posts and Telecommunications, Beijing, P.R. China); Jiaxi Di (Beijing University of Posts and Telecommunications, P.R. China); Xinyu Zhang (Beijing University of Posts and Telecommunications, P.R. China); Xaiofei Wu (Beijing University of Posts and Telecommunications, P.R. China)
The rapid developments in Internet are reshaping many of our routine daily activities, ranging from how we communicate with our friends to how we shop. Understanding the human behaviors and dynamics in such a large-scale social network is essential for better system design, service provisioning, and network management. In this paper, based on real traffic flow data collected from operational networks of Internet Service Provider, the flow graph is constructed to model the interactions among users. We focus on three of the most popular interactive applications on Internet, QQ, Skype and MSN, and investigate the statistical characteristics of the flow graphs. The degree distribution and strength distribution of the flow graphs are analyzed, and the community structure is also discussed. Comparative analysis results show different characteristics of the three interactive applications, which imply the heterogeneous user behaviors on Internet.
11:37 Link Prediction of Community in Microblog Based on Exponential Random Graph Model
Chuang Zhang (Beijing University of Posts and Telecommunications, P.R. China)
Link prediction is to predict the possible links between nodes, which recommend the most possible new ties or missing links according to the information of nodes and edges existed in the network. Microblog is a new-style social network. People connect each other in Microblog with their own interest and form the community in Microblog. For the community, link prediction is to recommend users to each other, which is important for people interaction and information spreading. Traditional methods of link prediction are appropriate for all kinds of networks, but ignore the social attributes of people in the community. In this paper, the features of social network are fully considered. A sociological model: Exponential Random Graph Model (ERGM) has been introduced in link prediction for Microblog. Synthesizing the data of user attributes and network topology, a link prediction model has been established. It is different from other methods, this model considers the community as a global network, and all nodes and edges contribute to the prediction of links. The result shows that this model has a significant effect for link prediction of community in Microblog.

1:00 PM - 4:00 PM (America/New_York)

SS06-1: Next Generation Network Security 1go to top

Room: Bally
Chair: Anand R. Prasad (NEC Corporation, Japan)

1:00 PM - 2:30 PM (America/New_York)

IMET2: IoT, M2M and Enabling Technologies 2go to top

Room: Central Park
Chair: Michele Nati (University of Surrey, Guildford & University of Rome "La Sapienza", United Kingdom)
1:00 Link-Reliability Based Two-Hop Routing for QoS Guarantee in Wireless Sensor Networks
ShivPrakash Thyagaraj (University Visvesvaraya College of Engineering, India); Raja K b (Bangalore, India); Venugopal Kuppanna Rajuk (University Visvesvaraya College of Engineering, India); L M Patnaik (Defence Institute of Advanced Technology, India); Sitharam Iyengar (Louisiana State University, USA)
This paper proposes a Link Reliability based Two-Hop Routing protocol for wireless sensor networks (WSNs). The protocol achieves to reduce packet deadline miss ratio (DMR) while considering link reliability, two-hop delay and power efficiency and utilizes memory and computational effective methods for estimating the link metrics. Numerical results provide insights that the protocol has a lower packet deadline miss ratio and longer sensor network lifetime. The results show that the proposed protocol is a feasible solution to the QoS routing problem in wireless sensor networks that support real-time applications.
1:22 Study for Renewable Energy Telemetry using a Decentralized Cloud M2M System
George Suciu (Politehnica University of Bucharest & BEIA Consult International SRL, Romania); Simona Halunga (University POLITEHNICA of Bucharest, Romania); Octavian Fratu (University Politehnica of Bucharest, Romania); Andrei Vasilescu (BEIA, Romania); Victor Suciu (BEIA / UPB, Romania)
Renewable energy sources are increasingly used for providing green alternatives to existing energy producers and need to be constantly monitored for optimizing the power grid. Unfortunately, such micro power plants are located in difficult to access remote locations where often only satellite or sparse GSM radio signals are available. In this paper we study the way how to use a decentralized cloud system, based on general systems and RTU (Remote Telemetry Units), for tele-monitoring of such objectives. In our proposed cloud M2M system, each RTU communicates by radio with a telemetry data gateway connected to a cloud computing infrastructure equipped with appropriate software that delivers processed data. Finally, we present the measurement results for a hydro-energy case study and discuss the applicability for other renewable sources such as solar or wind energy.
1:45 SmartCampus: A user-centric testbed for Internet of Things experimentation
Michele Nati (University of Surrey, Guildford & University of Rome "La Sapienza", United Kingdom); Alexander Gluhak (The University of Surrey, United Kingdom); Hamidreza Abangar (University of Surrey, United Kingdom); William Headley (University of Surrey, United Kingdom)
The Internet of Things (IoT) is not only about improving business processes, but has also the potential to profoundly impact the life of many citizens. Likewise the IoT can provide an useful tool for the longitudinal observation of human behavior and the understanding of behavioral patterns that can inform further IoT technology design. Today experimentation with IoT technologies is predominately carried out in lab based testbeds. There is however an emerging need for increased realism of the experimentation environment, as well as involvement of real end users into the experimentation lifecycle. In this paper we present SmartCampus, a user centric experimental research facility for IoT technologies. The current testbed deployment is focused on Smart Buildings, a key building block for cities of the future. Unlike current lab based testbeds, SmartCampus deeply embeds heterogeneous IoT devices as a programmable experimentation substrate in a real life office environment and makes flexible experimentation with real end users possible. We present the architecture realization of the current facility and underlying considerations that motivated its design. Using several recent experimental use cases, we demonstrate the usefulness and potential of such experimental facilities for user-centric IoT research.
2:07 SmartSantander: Experimentation and Service Provision in the Smart City
Luis Sanchez (University of Cantabria, Spain); Veronica Gutierrez (University of Cantabria, Spain); Jose A Galache (University of Cantabria, Spain); Pablo Sotres (University of Cantabria, Spain); Juan Ramón Santana (University of Cantabria, Spain); Javier Casanueva (Universidad de Cantabria, Spain); Luis Muñoz (University of Cantabria, Spain)
This paper describes the deployment and high-level architecture of the Internet of Things experimentation facility being deployed at Santander city. SmartSantander is a unique in the world city-scale experimental research facility in support of typical applications and services for a smart city. The testbed that has been deployed has a dual purpose. On the one hand it will allow real-world experimentation on Internet-of-Things related technologies (protocols, middlewares, applications, etc.). On the other hand it is currently supporting the provision of smart city services aimed at enhancing the quality of life in the city of Santander. Tangible results are expected to greatly influence definition and specification of Future Internet architecture design from viewpoints of Internet of Things and Internet of Services. This paper presents the physical deployment carried out in the city of Santander and the high-level architecture supporting the experimentation and service provision duality. Moreover, a brief description of the mechanisms supporting the experimentation life cycle will be done. Finally, the services that are being provided to the city will also be sketched.

SS01-2: Recent Issues in Mobile and Wireless Networksgo to top

Room: Fairmount Park
Chairs: Der Jiunn Deng (National Changhua University of Education, Taiwan), Chih-Cheng Tseng (National Ilan University, Taiwan)
1:00 Improving Efficiency and Fairness in IEEE 802.11 Infrastructure WLANs with Station-to-Station Traffic
Chih-Cheng Wei (National Kaohsiung University of Applied Sciences, Taiwan); Wei-Cheng Lin (National Kaohsiung University of Applied Sciences, Taiwan); Yeong-Sheng Chen (National Taipei University of Education, Taiwan); Chih-Heng Ke (National Quemoy University, Taiwan)
In a wireless local area network (WLAN) configured with the infrastructure mode, the access point (AP) not only handles the download or upload traffic between the Internet wired hosts and the mobile stations, but also forwards the traffic from a mobile station to a mobile station, which is called the station-to-station (S2S) traffic. In the IEEE 802.11 distributed coordination function (DCF), all the mobile nodes and the AP has the same probability to access the medium. Therefore, the total probability of uploading packets from all mobile stations is much more than the probability of transmitting packets from the AP. Consequently, the AP becomes a bottleneck and results in the unfair bandwidth sharing problem. However, most existing works addressing on this problem did not take the station-to-station traffic into consideration. In this study, a mechanism with dual queues and multiple transmission opportunities is proposed to tackle this problem. The proposed mechanism can be implemented at the AP in the MAC layer without modification of the standard for the mobile stations. Simulation results show that, in an infrastructure WLAN, the proposed mechanism not only can improve the efficiency and fairness but also can enhance the throughputs of station-to-station traffic.
1:30 Energy-Efficient Cooperative Diversity with Incremental Relaying
Yawgeng A. Chau (Yuan-Ze University, Taiwan); Mostafa Kamil Abdulhusain Al-Harbawi (Yuan-Ze University, Taiwan)
Cooperative diversity with a dual-hop demodulate-and-forward (DF) incremental relay (INR) is analyzed, where selection combining (SC) is employed at the destination node when the INR procedure is activated. To evaluate the end-to-end reception performance, BPSK signaling over independent and identically distributed (i.i.d.) Rayleigh fading channels is considered. The bit error rate (BER) of the end-to-end reception and switching rate are derived. Numerical results of BER performance are presented. Based on the numerical results, the proposed INR scheme outperforms the existing distributed switch-and-stay (DSSC) or simplified incremental relaying (S-IR) schemes.
2:00 Applying Simulated Annealing to Joint Routing, Scheduling and Variable-Width Channel Allocation for Multi-hop WMNs
Chun-Cheng Lin (National Chiao Tung University, Taiwan); Wan-Yu Liu (Aletheia University, Taiwan); Chun-Hung Chou (National Chiao Tung University, Taiwan); Der-Jiunn Deng (National Changhua University of Education, Taiwan)
Wireless Mesh Networks (WMNs) is more focused because of the advantages of low implementation costs and wide coverage. In this thesis, we want to solve the joint routing, scheduling and channel assignment problem in the single-radio, multi-channel WMNs. These three problems all relate to the transmission time. Routing problem is to find the transmission paths for the packets; scheduling problem is to plan the order of packets; channel assignment related about interference and concurrency. There are some researches which focus on the joint routing, scheduling and channel assignment problem in the past. However, they can only solve the problem in a small number of nodes' topology and didn't consider the effect of signal interference with the exact methods. Their methods are not efficient and do not meet to reality. With regards to this, we will use the concept of Simulated Annealing to design a new coding method which could divide the time into time slots to show us the dynamic process of packets. In addition, this thesis demonstrates a variable bandwidth channel allocation method which achieves a good balance between higher concurrency and better control of interference. We hope to improve the scalability and efficiency of the problem with the help of the meta-heuristic, expecting to find a feasible solution in a short time. The experimental results showed that in a small number of nodes and low traffic load case, the simulated annealing can find a good solution like the exact methods and variable-width channel allocation indeed better than fixed-width method. Besides, in more number of nodes case, the simulated annealing still can find a feasible solution in a short time.

SS02-2: Social Network Analysis and Mininggo to top

Room: Monticello Park
Chair: Jun Guo (BUPT, P.R. China)
1:00 Evaluating Quality of Web2.0 UGC Based on User Authority and Topic Distribution
Boyuan Wang (Beijing University Of Posts And Telecommunications, P.R. China); Xin Lin (Beijing University Of Posts And Telecommunications, P.R. China); Lei Li (Beijing University of Posts And Telecommunications, P.R. China)
The Web2.0 technologies are growing very fast with more and more studies are being made for the specific User Generated Content (UGC). UGC could be composed and published by every user, which is a distinct character of Web2.0 compared with Web1.0. As a result, quality of UGC may not be well-guaranteed. When being used in many applications, such as Information Retrieval, Data Mining, Topic Detection and Tracking, UGC itself demands a reasonable quality evaluation. In this paper, we put forward a synthetic evaluation method for UGC quality of content via user authority and topic distribution. As to user authority, we consider various features of users, including the basic registration information, the relative static online social relations and dynamic interactions between users. We adopt Link Analysis based on user credibility and Generalized Regression Neural Network (GRNN) to rate user authority. As to topic distribution, there are multiple authors contributing to the generation of UGC. We analyze the probabilistic topic distribution of authors and UGC based on textual content using Author-Topic Model (AT). We've also integrated the author's actual behavior during the composing of UGC to compute the contribution degree of user authority. Finally, we combined the user authority and the contribution degree to evaluate the overall quality of a multi-author UGC. Experiments with real dataset collected from TianYa have shown that the proposed method could evaluate UGC reasonably.
1:22 A Competition-based Recommender System
Shaowei Jiang (Beijing University of Posts and Telecommunications & Center for Intelligence Science and Technology, P.R. China)
There are a large number of items with users' ratings on the internet. Instead of predicting items' ratings with the item content or the user-item-rating matrix, this paper proposes an approach to predict items' ratings basing on paired comparisons among contents of items with different ratings. We assume that the user interest on each item can be represented by the combination of different content features, and employ Bradley-Terry model to confirm the user interest value of each feature. Experimental results show that the competition-based recommender system outperforms popular approaches.
1:45 Friendship and Affiliation Co-recommendation via Collective Latent Factor BlockModel
Sheng Gao (University of Posts and Telecommunications, P.R. China)
With the increasing of online social networks, people always form the friendship networks among their social neighborhood, and also associate themselves with circles or communities due to their common interest. Thus there are two related networks: the friendship network among users as well as the affiliation network between users and circles. In this paper, we address the problem of collaborative recommendation for friendships and affiliations in online social networks. For that we propose the Collective Latent Factor BlockModel (CLFBM) to collectively discover globally predictive intrinsic properties of users and capture the interpretable latent block structure corresponding to the circle information. The proposed model is exploited in a transfer learning framework that extracts knowledge from the two related networks and generates recommendations for friendships and affiliations. The extensive experiments on the real world datasets suggest that our proposed CLFBM model outperforms the other state of the art approaches in the recommendation tasks.
2:07 A Cluster Validity Index based on Frequent Pattern
Hongyan Cui (Beijing University of Posts and Telecommunications, P.R. China); Kuo Zhang (Beijing University of Posts and Telecommunications, P.R. China); Yan Ma (Bejing University of Posts and Telecommunications, P.R. China); Xu Huang (University of Canberra, Australia); Yunjie Liu (Beijing University of Posts and Telecommunications, P.R. China)
Since a clustering algorithm can produce as many partitions as desired, one need to assess their quality in order to select the partition that most represents the structure in the data. This is the rationale for the cluster-validity (CV) problem and indices. This paper proposes a CV index for fuzzy-clustering algorithm, such as the fuzzy c-means (FCM) or its derivatives. Given a fuzzy partition, this new index uses global information and is based on more logical reasoning than geometrical features. Experimental results on artificial and benchmark datasets are given to demonstrate the performance of the proposed index, as compared with traditional and recent indices.

2:30 PM - 4:00 PM (America/New_York)

IMET3: IoT, M2M and Enabling Technologies 3go to top

Chair: Rasmus Hjorth Nielsen (Cisco Systems, Denmark)
2:30 H-GCF: A Hybrid Green Conflict Free Scheduling Algorithm for Mobile Wireless Sensor Networks
Pranav Pawar (University of Aalborg, India); Rasmus Hjorth Nielsen (Cisco Systems, Denmark); Neeli Rashmi Prasad (Center for TeleInFrastructure (CTIF), Denmark); Ramjee Prasad (Aalborg University, Denmark)
Wireless Sensor Networks (WSNs) enable a wide range of application that necessitates advances in protocol performance, security, and energy efficiency. Medium access control (MAC) layer protocols are essential in providing these advances due to their functionality domain in resource allocation and utilization. The contribution of this paper is the proposal of a novel cluster based hybrid time division multiple access (TDMA) scheduling MAC for Mobile-WSNs, to support non-uniform time mobility for real time applications. The hybrid approach improves scalability by utilizing the cluster-based approach while it also enables to support varying mobility conditions in the network. The paper presents the design, implementation and performance evaluation of the hybrid TDMA scheduling algorithm called Hybrid-Green Conflict Free (H-GCF) for intelligent Mobile-WSN applications. H-GCF combines the strength of Green Conflict Free (GCF) and Multicolor-GCF (M-GCF) while counterbalancing their weaknesses. H-GCF works using M-GCF under static and low mobility conditions and using GCF under high mobility conditions. As seen from the results, these distinctive features of H-GCF make it energy-, delay-, and throughput efficient with good scalability under fixed- and random- mobility conditions.
2:45 Coverage Improvement in Clustered Wireless Sensor Networks by Relocating Mobile Nodes based on Waypoints
Prateek Mathur (Aalborg University, Denmark)
Achieving effective coverage and efficient clustering of sensor nodes are important aspects of wireless sensor networks (WSNs). In this paper we present a novel approach for achieving improvement in both aspects in an integrated manner. Coverage improvement is done based on information exchange by clusters with relocation of mobile nodes between the clusters. Mobile nodes are guided by waypoints between source and destination clusters without use of localization services. The simulation results have been presented which state the effectiveness of the proposed approach. Mobile node relocation has been done in such a way that they could volunteer as future cluster head (CH) and this has been justified by the simulation results. This paper stresses the requirement for considering both coverage and clustering in an integrated manner and proposes a sequential process for WSNs to be followed after initial deployment for effective operation.
3:00 Efficient and Scalable Location and Mobility Management of EPCglobal RFID System
Bayu Anggorojati (Aalborg Universitet, Denmark); Parikshit Narendra Mahalle (Aalborg University, Denmark); Neeli Rashmi Prasad (Center for TeleInFrastructure (CTIF), Denmark); Ramjee Prasad (Aalborg University, Denmark)
The integration of the Radio Frequency IDentification (RFID) network into the Internet Protocol (IP) network has been quite an interesting topic recently in order to realize the Internet of Things (IoT) in the context of RFID. The development of the RFID technology, which is driven mainly by the logistic related industries, is based on enterprise system that does not take full advantage of the features in the especially mobile IP networking, such as mobility management. However, most of the works in the integration of RFID and IP network does not take the full advantage of all the RFID middleware components as defined in the EPCglobal standard. The main contribution of this work is the full integration of RFID middleware with the IP network through a testbed implementation. The performance of our proposed work is measured in terms of delay in two cases, i.e. tags registration and tracking, and is then compared with the existing RFID middleware implementation. The measurement results show that the delay of our proposed work is significantly lower than that of existing solution, especially in the tags registration case.
3:15 Game Theoretic Modelling of WSN Jamming Attack and Detection Mechanism
Sachin Babar (Aalborg University, India); Neeli Rashmi Prasad (Center for TeleInFrastructure (CTIF), Denmark); Ramjee Prasad (Aalborg University, Denmark)
Nowadays wireless sensor networks (WSNs) are going to be more prone to different security threats and attacks. The different attack reduces the capability of WSN, to work for long time. It largely effects on resource consumption of network and increases the energy consumption, delay, and reduces the throughput. Among all the different WSN security attacks, jamming attack affects largely on performance of WSN. Jamming attack jams the network by making resources busy for long time and increases the crunch of resources, which leads to reduction in performance. The aim of the paper is to form the game theoretic model of the jamming attack, to understand the different strategies of jamming game when jammer behaves in different ways. The paper also proposes the game theory based detection mechanism for all kind of jamming attacks. The proposed detection mechanism shows better energy consumption, throughput, and delay in different realistic situations of network (e.g. varying- amount of traffic and number of malicious nodes) as compared with existing optimal strategy solution.
3:30 Information Source Selection and Management Framework in Wireless Sensor Networks
Sonam Tobgay (Aalborg University & Royal University of Bhutan, Denmark); Rasmus Olsen (Aalborg University, Denmark); Ramjee Prasad (Aalborg University, Denmark)
With an advancement of technologies especially in the field of electronics, different types of sensors which can measure same physical phenomenon can be found in the market. Therefore, it is likely that different types of sensors which measure same physical phenomenon will be used for some applications. Different properties and characteristics like sensitivity, response time etc., of these different sensors will result in generating information at different rates. When these different types of sensors are deployed to collect same information, the users have choice to select from different information sources based on their preferences and requirement. In addition, the user can also switch from one information source to another when the current information source either becomes unavailable or the users requirement changes. In this paper, based on above argument, we develop a reliable information source selection and management framework and presents an algorithm which selects the information source based on the information mismatch probability [1]. The sampling rate for every access is decided as per the maximum allowable power consumption limit.
3:45 Radio Frequency Energy Harvesting for Long Lifetime Wireless Sensor Networks
Bo Han (Aalborg University & Athens Information Technology, Denmark); Rasmus Hjorth Nielsen (Cisco Systems, Denmark); Ramjee - Prasad (Aalborg University, Denmark)
In wireless sensor networks energy scarcity is a major concern on energy consumption, and by properly designing on the node network architecture or selecting efficient protocols of the networks, the maximum energy can be reduced significantly thereby increasing the network lifetime. However, in most of the cases, the sensor nodes are either powered by none replaceable batteries, or there will be a considerable replacement cost. Thus a self rechargeable sensor node design is necessary: the sensor node should be able to harvest energy from the environment. Among the existing techniques, harvesting energy from the radio frequency waves gives the lowest system design. Previous research on RF energy harvesting is based on the model that the radio energy is omnidirectional in the air. In this paper, a directional transmission or receiving model is proposed which can further overcome the path loss of the RF signals. On the node level, a virtual Floating gate based CMOS biasing is used for the energy conversion circuit. With the proposed technique, the sensor node is able to harvest the energy from base station up to 30 meters.

S11-1: M2M applications - Trends & Challengesgo to top

Room: Central Park
Chair: Sofoklis Kyriazakos (Aalborg Universitet, Denmark)
2:30 A WSN Architecture Design for Fast Moving Objects Tracking
Cosimo Stallo (University of Rome Tor Vergata, Italy); Andrea Coluccia (University of Rome Tor Vergata, Italy); Giovanni Savarese (University of Rome 'Tor Vergata', Italy); Manuela Vaser (University of Rome "Tor Vergata" & Telecom Italia SpA, Italy); Marina Ruggieri (University of Roma Tor Vergata, Rome, Italy); Ugo Stocco (Loratek, Italy)
The scenario comprises a large number of fast moving targets, such as racing cars, and several cameras within a predefined area. Each camera temporarily zooms into one particular target according to some predefined optimization criteria and, forwards its information data-stream to a control-station. In short, the classical camera-man in the field can be omitted. The task is to estimate the instant position of each target. This information is then used to generate control commands for the respective video-camera to zoom on this particular target. The specifications are as follows. i) Navigation information is sent with data rate 4800 kbps; ii) the number of targets is limited to 30; iii) the targets move up to 85 m/s (=300 km/h); iv) ranging distance is 3000 meters; v) the targets appear "ad-hoc", vi) the radio interface must operate in one of the (industrial, scientific, and medical) ISM frequency bands. One way to meet this task is to equip each target, subsequently referred as Mobile stations (MS), with a navigation device such as GPS. Though this approach has been followed several time in the past, the challenges are i) multiples MSs have to be tracked simultaneously over large distances at high speed (i.e., data has to be acquired within a fraction of a second) and ii) the navigation-communication (NAVCOM) integration on chip in the racing cars. The paper focuses on the NAVCOM architecture. Following this approach, all MSs are equipped by a micro-controller, a GPS navigation device and an air-interface. These MSs communicate with one Base-Station (BS) located in the field. The BSs have one micro-controller and two air-interfaces, to communicates with the MSs and the indoor Control-Station (CS), respectively. For the air interface, we have chosen the ISM 2.4 GHz (2.4 - 2.4835 GHz) with a total data rate of 250 kbps without duty cycle limitations and emission power of 20dBm EIRP (regulated by ETSI) when the number of channels is less than 75. Notice that the tracking range, supported by this emission power, is too small for our purpose. This problem needs to be tackled at MAC layer level in the OSI reference model. The standard IEEE 802.15.4 protocol is robust against interference, as it uses Direct Sequence Spread Spectrum modulation and Carrier Sense Multiple Access-Collision Avoidance (CSMA-CA) technique. It also works with low-duty cycles - the transmitter can be sleeping up to 99% on average - however, only star topologies are supported. We need a mesh topology to reach all targets spread over several kms in distance. The most known protocol on top of 802.15.4 is Zigbee, but there are a lot of others such as Wireless HART, ISA - SP100, IETF Ipv6 - LoWPan, and Digi's own mesh protocol DigiMesh. The last one is of particuar interest, as it provides a completely distributed network where all nodes talk among them using peer-to-peer. All the nodes can sleep and route their brother's packets. On top of that self-healing, self-discovery, and dense network operation support network stability. In few of above, we use the commercial air-interface Xbee Digimesh2.4 supporting 12 channels. The devices can be configured by Xbee's XCTU environment via UART/USB ports. The navigation subsystem includes a commercial GPS receiver by Origin. This device has a microstrip patch antenna, 20 channels for search, 12 ones for track. Moreover, it shows an acquisition sensitivity of -157 dBm and UART and SPI Interfaces. Finally, the accuracy is 4 meters (including SBAS). The microcontroller is a commercial product by Microchip (PIC32 series). The on-board microcontroller with an integrated EEPROM filters the National Marine Electronics Association (NMEA) sequence provided by the GPS receiver, to extract time, date, latitude, and longitude. Then, it forwards the result along with a pre-assigned identification string (ID) to the BS. Each MS has a distinguished ID. As the targets run on battery, we are concerned on power consumption of the MS. To increase power efficiency, the final paper will present a protocol on top of digimesh that minimizes exchange of information between respective target and base station. Moreover, a detailed description of the network architecture will be presented, the integration of hardware will be realized and analyzed. The performance of the proposed schemes will be measured and analysed with the aid of field tests.
3:00 A Software Defined Networking-based Context-Aware Framework Combining 4G Cellular Networks with M2M
Manuela Vaser (University of Rome "Tor Vergata" & Telecom Italia SpA, Italy); Giovanni Savarese (University of Rome 'Tor Vergata', Italy); Marina Ruggieri (University of Roma Tor Vergata, Rome, Italy)
In the Machine-to-Machine (M2M) paradigm applications often rely on real-time information, such as controlling sensitive equipment, industrial alarms and controls, traffic systems. This kind of applications needs low latency, function that is well provided by the Fourth Generation (4G) Long Term Evolution (LTE) cellular network. Another characteristic that becomes necessary in specific M2M context - such as military applications - is the access to network resources with priority mechanisms. The latter approach is possible in LTE networks, by means of data flow handling in different classes that provides specific Quality of Service (QoS) to the user belonging to each class. As LTE network deployment continues to expand around the world, these types of M2M applications will grow as well. Moreover, LTE is a scalable all-IP based network, and it is deployed with a possible support for IPv6 addressing. The latter expands the IP address space, making it possible to enable the M2M vision of an "Internet of Things" (IoT), when potentially every object of our everyday life can be connected on IP network, by mean of an IP address. A large number of M2M terminals can be placed in various locations where cellular networks - LTE in particular - will be the only available connection to transport the monitoring information collected by sensors to a processing and management entity. The latter will process those information and make them available to M2M users. The paper investigates how to implement a challenging and innovative framework that, using information collected by M2M terminals, makes the LTE network context-aware of a particular emergency situation, and makes it possible to reconfigure the cellular network resources allocation with an high level of flexibility (for example in term of bandwidth dedicated to a particular service) and reactivity, in order to redirect the workload of damaged network elements in the mentioned area. In the above framework, Software Defined Networking (SDN) represents a very promising technology to provide the network with an effective level of adaptability. SDN proposes to improve network flexibility and manageability separating the traditional vertically integrated networking stack. SDN decouples the control plane from the packet forwarding plane, by means of an advanced software paradigm that can be run externally to the packet forwarding hardware. The network equipment performs basic packet-processing functions at the request of a logically-centralized controller that sends the control information to the data plane. This architecture provide a view of entire network topology enabling the network operator to shape traffic load in real-time without having to touch individual switches. The paper will describe the mentioned SND-based approach, highlighting the expected features and performance as well as the benefits at both network operator and final user levels.
3:30 Cognitive Radio Inspired M2M Communications
Elias Tragos (Institute of Computer Science, FORTH, Greece); Vangelis Angelakis (Linköping University, Sweden)
The Internet of Things (IoT) presents itself as one of the basic pillars of the Future Internet. Such an extended network of heterogeneous "things" forms a global network infrastructure supported by several communication protocols where physical and virtual objects are interconnected. It is envisaged that billions of machines will be connected to the Internet, pushing the current communication technologies to their limits in terms of connectivity and performance. The wireless interconnectivity of a large number of devices in the ISM bands is a fundamental issue due to the resulting high interference environment, which degrades severely the performance and the connectivity of these devices. The Cognitive Radio technology can help mitigate the interference effect in such environments, employing smart techniques for accessing the wireless spectrum in an opportunistic manner. This paper discusses the adaptation of Cognitive Radio technology for enhancing the machine-to-machine communications, presenting the challenges and open issues for future research.

SS03: Inference in Wireless Sensor Networksgo to top

Room: Fairmount Park
Chair: Pramod Varshney (Syracuse University, USA)
2:30 Further Results on Noise-Enhanced Distributed Inference in the Presence of Byzantines
Aditya Vempaty (Syracuse University, USA); Venkata Sriram Siddhardh Nadendla (Syracuse University, USA); Pramod Varshney (Syracuse University, USA)
The problem of Byzantine (malicious sensors) threats in a distributed detection framework for inference networks is addressed. Impact of Byzantines is mitigated by suitably adding Stochastic Resonance (SR) noise. Previously, Independent Malicious Byzantine Attack (IMBA), where each Byzantine decides to attack the network independently relying on its own observation was considered. In this paper, we present further results for Cooperative Malicious Byzantine Attack (CMBA), where Byzantines collaborate to make the decision and use this information for the attack. In order to analyze the network performance, we consider KL-Divergence (KLD) to quantify detection performance and minimum fraction of Byzantines needed to blind the network ($\alpha_{blind}$) as a security metric. We show that both KLD and $\alpha_{blind}$ increase when SR noise is added at the honest sensors. When SR noise is added to the fusion center, we analytically show that there is no gain in terms of $\alpha_{blind}$ or the network-wide performance measured in terms of the deflection coefficient. We also model a game between the network and the Byzantines and present a necessary condition for a strategy (SR noise) to be a saddle-point equilibrium.
2:52 Distributed Detection of A Common Random Signal
Hao Chen (Boise State University, USA); Uri Rogers (Boise State University, USA); Tsang-Yi Wang (National Sun Yat-sen University, Taiwan)
We consider the problem of distributed detection of a common random signal. After evaluating the detection performance of the centralized detector, we propose two distributed detectors. Detector 1 employs energy detector at the local sensors and a monotone fusion rule at the fusion center (FC). Detector 2 uses a Sign detector at each local sensor and a two-sided test at the FC. Detector 1 performs better for the somewhat extreme cases where the number of sensors is very small. When the number of sensors is reasonably large, we prove that detector 2 outperforms detector 1 using the Kullback-Leibler divergence (KLD) and Stein's lemma. In fact, for sensor networks with a reasonable number of sensors, the performance of detector 2 is about \sqrt{\frac{2}{\pi}} as effective as the centralized case where no local quantization is made. We validate the derived results via numerical Monte Carlo Simulations.
3:15 Bandwidth-efficient Dynamic Event Region Detection and Reconstruction in Wireless Sensor Networks
Tao Wu (Oklahoma State University, USA); Qi Cheng (Oklahoma State University, USA)
In this paper, the problem of dynamic event region detection and reconstruction using a wireless sensor network is studied. The spatiotemporal relationship of the evolving field is assumed and modeled by dynamic Markov random fields. Observations are collected from a network of sensors distributed in the field. To meet the stringent bandwidth and energy constraints in wireless sensor networks, only quantized observations from a subset of sensor nodes are allowed to be transmitted to the center. To reconstruct and track the field state map at a control center at each time step, a processing framework including sensor selection, local observation quantization and central processing is proposed. The performance of the proposed processing framework is analyzed through simulations and the effectiveness and efficiency is demonstrated by comparing with other methods.
3:37 Joint Object Detection and Tracking in Sensor Networks
Ruixin Niu (Syracuse University, USA)
A nonlinear filtering based approach that fuses sensor data from the local sensors is proposed to jointly detect and track a moving object in a sensor field. First, the optimal detection algorithm based on the optimal nonlinear filter and the likelihood ratio test is provided. Then, a computationally efficient approach based on the extended Kalman filter is proposed and applied to jointly detect and track an object with very weak signal in a passive sensor network. The signal intensity is assumed to be inversely proportional to a power of the distance from the object. Simulation results show that the proposed detection approach can quickly detect the object after it appears in the sensor field with very high detection performance, even when the object state estimate is not very accurate.

SS04: Information Theoretic Physical Layer Security (Invited Papers)go to top

Room: Monticello Park
Chair: Ravi Tandon (Virginia Tech, USA)
2:30 On the Tradeoffs Between Network State Knowledge and Secrecy
Samir M. Perlaza (Princeton University, USA); Arsenia Chorti (Princeton University & ICS FORTH, USA); H. Vincent Poor (Princeton University, USA); Zhu Han (University of Houston, USA)
In this paper, the impact of network-state knowledge on the feasibility of secrecy is studied in the context of decentralized active eavesdropping. The main contribution is the introduction of several scenarios in which increasing the available knowledge at each of the network components leads to some paradoxical observations in terms of the average secrecy capacity and average information leakage. These observations are in the context of a broadcast channel similar to the time-division downlink of a single-cell cellular system. Here, providing more knowledge to the eavesdroppers makes them more conservative in their attacks, and thus, harmless in terms of average information leakage. Similarly, providing more knowledge to the transmitter makes it more careful and less willing to transmit, which reduces the expected secrecy capacity. These observations are illustrated with a numerical analysis that shows the impact of most of the network parameters in the feasibility of secrecy.
2:52 Optimality of Beamforming and Closed Form Secrecy Capacity of MIMO Wiretap Channels with Two Transmit Antennas
Jiangyuan Li (Rutgers-The State University of New Jersey, USA); Athina Petropulu (Rutgers, The State University of New Jersey, USA)
A Gaussian multiple-input multiple-output (MIMO) wiretap channel model is considered. The input is a two-antenna transmitter, while the outputs are the legitimate receiver and an eavesdropper, both equipped with multiple antennas. All channels are assumed to be known. The problem of obtaining the optimal input covariance matrix that achieves secrecy capacity subject to a sum power constraint is addressed, and a closed-form expression for the secrecy capacity is obtained. The sufficient and necessary condition for beamforming to be optimal is also given.
3:15 Anonymity in Wireless Networks under Capture or Selective Jamming: An Admissible Length Study
Abhishek Mishra (Lehigh University, USA); Parv Venkitasubramaniam (Lehigh University, USA)
Traffic analysis, where eavesdroppers retrieve networking information such as source-destination pairs and paths of data flow, severely compromises user privacy and can equip an adversary to launch more powerful network attacks. In wireless networks, such information can be easily obtained by using a radio receiver or merely an energy detector. Furthermore, active adversaries can intercept transmissions by capturing transmitted packets or time selectively jamming certain links thus distorting the timing of packet flows. By carefully selecting the packets to intercept, the adversary can use the distorted timing signature to improve his detection of the path of packet flows. Anonymous communication, where users exchange information without revealing the communicating parties is essential in any data network. On the Internet, anonymous communication is typically enabled using Chaum mixes-relay nodes or proxy servers which use cryptographic and batching strategies to mask source identities. In this work, a theoretical framework is proposed to investigate the ability of a mix to thwart timing analysis by active adversaries who can capture packets or selectively jam links. Specifically, using the detection time of an adversary as a metric, the maximum achievable anonymity of a mix is characterized as a function of its available memory and the number of packets Eve can capture. When the capture capacity of the adversary is unbounded, the use of dummy transmissions by the mix to maximize detection time is investigated; upper and lower bounds are provided on the achievable detection time as a function of the allowable rate of dummy transmissions.
3:37 Protecting Physical Layer Synchronization: Mitigating Attacks Against OFDM Acquisition
Matthew La Pan (Virginia Tech, USA); Marc Lichtman (Virginia Tech, USA); T. Charles Clancy (Virginia Tech, USA); Robert McGwier (Virginia Tech & AMSAT, Inc. and Flex Radio System, Inc., USA)
Orthogonal Frequency Division Multiplexing (OFDM) has become an integral physical layer feature of 4G systems, and will continue to be utilized in future communications standards. In systems that utilize OFDM, synchronization between the transmitter and the receiver is paramount. However, many current acquisition algorithms and implementations are susceptible to corruption by adversarial communications systems. This paper outlines two improvements to OFDM timing and frequency offset estimation; sync-amble randomization and Cross Ambiguity Function (CAF) acquisition. Both analysis and simulation results are provided which suggest that both of these strategies offer improvements in physical layer security to OFDM synchronization in the presence of attacking communication systems, with minimal impact on overall performance.

4:30 PM - 6:00 PM (America/New_York)

SS06-2: Next Generation Network Security 2go to top

Room: Bally
Chair: Anand R. Prasad (NEC Corporation, Japan)
4:30 Security Attacks Against the Availability of LTE Mobility Networks: Overview and Research Directions
Roger Piqueras Jover (AT&T Security Research Center, USA)
Modern LTE (Long Term Evolution) cellular networks provide advanced services for billions of users that go beyond traditional voice and short messaging traffic. The recent trend of Distributed Denial of Service (DDoS) attacks impacting the availability of communication systems illustrate the importance of strengthening the resiliency of mobility networks against Denial of Service (DoS) and DDoS threats, ensuring this way full LTE network availability against security attacks. In parallel, the advent of the Advanced Persistent Threat (APT) has capsized the common assumptions about attackers and threats. When it comes to very well planned and funded cyber-attacks, the scale of the threat is not the key element anymore. Instead, scenarios such as a local DoS attack, for example, against the cell service around a large corporation's headquarters or the Stock Exchange become very relevant. Therefore, traditionally overlooked low range threats, such as radio jamming, should not be de-prioritized in security studies. In this paper we present an overview of the current threat landscape against the availability of mobility networks. We identify a set of areas of focus that should be considered in mobility security in order to guarantee availability against security attacks. Finally, we introduce potential research directions, including a new attack detection layer, to tackle these problems. The final goal is to rethink the architecture of a mobility network within the current security context and threat landscape and considering the current evolution towards a near future scenario where nearly every electronic device will be connected through Machine-to-Machine (M2M) systems.
5:00 Attacks and Countermeasures on AES and ECC
Henrik Tange (Wireless Center CTIF Copenhagen, Denmark)
AES (Advanced Encryption Standard) is widely used in LTE and Wi-Fi communication systems. AES has recently been exposed to new attacks which have questioned the overall security of AES. The newest attack is a so called biclique attack, which is using the fact that the content of the state array is foreseeable while the rounds are performed. ECC (Elliptic Curve Cryptography) is used as a public key crypto system with the key purpose of creating a private shared between two participants in a communication network. Attacks on ECC include the Pohlig-Hellman attack and the Pollard's rho attack. Furthermore side-channels attacks can be applied to ECC. This paper reflects an ongoing research in the field of countermeasures against the attacks mentioned above.
5:30 The evolution of Inter-Working between eHRPD and LTE
Jialin Zou (Alcatel-Lucent, USA); Satish Kanugovi (Alcatel-Lucent, India); Subramanian Vasudevan (Alcatel-Lucent, USA); Orlett Pearson (Alcatel-Lucent, USA)
The Enhanced High-Rate Packet Data (eHRPD) system was developed to permit seamless mobility between Third Generation (3G) HRPD and Fourth Generation (4G) Long Term Evolution (LTE) cellular networks. The resulting network architecture is capable of supporting different modes of coupling between the two systems with different levels of optimization in terms of service interruption time and latency. We trace the evolution of the eHRPD system in 3GPP2 and summarize its key attributes that have made it attractive for deployment by network operators. Operators maintaining this integrated eHRPD-LTE network are also looking to maximize the utilization of air-interface resources dedicated to either technology. We describe and analyze a family of possible techniques for effective load balancing between eHRPD and LTE as a further augmentation of the eHRPD-LTE network.

S11-2: M2M applications - Trends & Challengesgo to top

Room: Central Park
Chair: Sofoklis Kyriazakos (Aalborg Universitet, Denmark)
4:30 Scenarios and Applications in a Things as a Service Environment
Sofoklis Kyriazakos (Aalborg Universitet, Denmark); Francisco Javier Nieto De-Santos (ATOS, Spain)
Recent advances of device manufacturing and communication technologies create the basis for an exponential grow of new devices with Internet connection in the next years. This will provide an unprecedented opportunity to create applications and services that go far beyond the mere purpose of each participant, as enabled by the interactions in this so-called Internet of Things (IoT). IoT applications that are growing with an increasing tendency, involve control and monitoring functions, where human-in-the-loop actions are not required. As a matter of fact, the only reason for having many of these applications is to remove human intervention for improved efficiency, security, and safety. The scenarios and applications we present in this paper are based on a novel architecture based on a so-called Things as a Service model enabling a Machine-to-Machine (M2M) environment, which will create a bridge between the real world (made of sensors, actuators, tags that are pervasive in our lives) and the virtual world (the Internet and its associated services).
5:00 An Open Framework for Accessing Things as a Service
Enzo Mingozzi (University of Pisa, Italy); Giacomo Tanganelli (University of Pisa, Italy); Carlo Vallati (University of Pisa, Italy); Valerio Di Gregorio (Intecs S.p.A., Italy)
Integration of existing isolated vertical systems into a new horizontal environment is today one of the main challenges in making real the Internet of Things vision. The design of a plat-form to allow services and applications accessing physical objects from different environments is the main challenge of the BETaaS (Building the Environment for the Things as a Service) project. In this paper the solution adopted in BETaaS to expose heterogeneous things to applications through a service-oriented interface is presented. The goal is to design a single open framework in which existing solutions and architectures can be integrated with limited efforts and modifications. In order to demonstrate the feasibility of the proposed design, a simple proof-of-concept implementation is presented.
5:30 An Architecture for a Platform Providing Things As A Service
Francisco Javier Nieto De-Santos (ATOS, Spain)
There are more and more devices surrounding us which provide new possibilities for end users. We propose a set of capabilities and functionalities which will exploit the new devices,enabling their usage by new applications and services. These capabilities lead the process of defining the architecture of a new platform which will facilitate advanced resources and things management, creating local clouds and providing improved functional and non-functional features such as semantic context management, security, reliability, virtualization, quality of service and scalability. The proposed architecture will be modular, flexible and scalable enough, being capable of evolving as new devices appear or new functionalities are required.

MIMO: MIMOgo to top

Room: Fairmount Park
Chair: Milica Pejanovic-Djurisic (University of Montenegro & Centre for Telecommunications, Montenegro)
4:30 A MIMO Approach for Increasing Spectrum Efficiency of OFDM-CDMA System with Pilot Tone
Zoran Veljovic (University of Montenegro, Montenegro); Ugljesa Urosevic (Faculty of Electrical Engineering, University of Montenegro, Montenegro); Milica Pejanovic-Djurisic (University of Montenegro & Centre for Telecommunications, Montenegro)
In this paper, MIMO OFDM-CDMA downlink scheme is proposed as a solution for increasing the spectrum efficiency of the OFDM-CDMA downlink system with pilot tone and threshold detection combining (optimum TDC). The new presented system with MIMO included uses space-time block coding applied to two, three and four transmit antennas. BER (Bit Error Rate) performance in the case of Ricean frequency selective fading is evaluated for the original system as well as for the one with MIMO included. For that reason an adequate simulation model is developed. The results show that for the same data rate the proposed system with two times less subcarriers, i.e. narrower occupied frequency band provides better BER performance than the OFDM-CDMA system with pilot tone.
4:48 A Study on Complexity Reduction of MIMO-ICI Canceller in Mobile Reception of OFDM
Akira Nakamura (Tokyo University of Science, Japan); Kohei Ohno (Meiji University, Japan); Makoto Itami (Tokyo University of Science, Japan)
In the next-generation wireless communication systems, further advance of OFDM(Orthogonal Frequency Division Multiplexing) and MIMO(Multi-Input Multi-Output) system is required. One of the major problems to be considered is ICI(Inter-Carrier Interference) generated by Doppler-spread under mobile reception of MIMO-OFDM systems. In this situation, reception characteristics are deteriorated significantly. The ICI canceller for MIMO-OFDM with complexity reduction can demodulate transmitted symbols. In order to realize an ICI canceller, it is necessary to reduce the complex calculations such as matrix operations. Therefor, complexity reduction of a MIMO-ICI canceller is proposed. Proposed complexity reduction scheme of a MIMO-ICI canceller can improve the influence of ICI with reduced complexity. The performance of the proposed scheme is evaluated by simulations.
5:06 Selective Beamforming for Inter-Cell Interference Mitigation in Coordinated Wireless LANs
Koichi Ishihara (NTT Corporation, Japan); Tomoki Murakami (NTT Corporation, Japan); Yusuke Asai (NTT, Japan); Masato Mizoguchi (NTT, Japan)
In future wireless LAN systems, the transmission bandwidth will become wider and the number of access points (APs) will increase as wireless LAN systems become more widespread. As a result, the number of available frequency channels will decrease and inter-cell interference (ICI) among APs with the same frequency channel will become a serious problem. To address this issue we previously proposed an ICI mitigation scheme based on coordinated APs, where a transmit beamforming scheme used for multiuser MIMO is applied to avoid the ICI effect. In this paper, we propose a selective beamforming scheme for ICI mitigation in wireless LAN systems. The scheme uses ICI power as a basis for selectively determining whether to perform null beamforming for each station (STA) in overlapping basic service sets (OBSSs) according to the ICI power. Computer simulation results confirm that the achievable rate obtained with the scheme improves and is higher than that obtained with either time resource sharing or conventional ICI mitigation in an OBSS environment.
5:24 A Low-Complexity Vector Precoding Scheme for Large Multiuser MIMO Systems
Wei Ding (Beijing University of Post and Telecommunications, P.R. China); Tiejun Lv (Beijing University of Posts and Telecommunications, P.R. China); Anzhong Hu (Beijing University of Posts and Telecommunications, P.R. China)
In this paper, the precoding problem for large multiuser multiple-input multiple-output (MU-MIMO) systems has been considered since precoding for such large systems has been a challenge on account of prohibitive complexity. Hence, we propose a well-performed low-complexity vector precoding scheme, which is termed as the oriented reactive tabu search (ORTS). Its low complexity is achieved by searching the perturbation vectors along a certain direction instead of all the possible candidates in the solution space. In addition, thanks to its ability of the ORTS scheme to escape from poor local minima, the improved performance is obtained as well. Furthermore, it is observed that the bit error rate (BER) performance increases with the number of simultaneously served user terminals in a near-exponential manner. Thus the proposed scheme is proper for the large systems in terms of complexity as well as performance. Numerical simulations verify the improved performance and the reduced complexity.
5:42 Interference Alignment Design for Two-Cell MIMO Uplink Systems with Limited Feedback
Di Fang (Beijing University of Posts and Telecommunications, P.R. China); Tiejun Lv (Beijing University of Posts and Telecommunications, P.R. China)
Many studies have combined interference alignment (IA) with limited feedback in cellular systems. The limited feedback will produce residual inter-cell interference (ICI), which causes system throughput loss. Some IA scheme has been proposed to mitigate the residual ICI. However, the residual ICI with the existing scheme is still significant. In this paper, we propose an IA scheme for two-cell multiple-input multiple-output (MIMO) uplink systems with limited feedback to mitigate the residual ICI more effectively. In the proposed scheme we design the receiver according to the estimated ICI. The proposed scheme minimizes the residual ICI, thus improving the performance of system throughput. Simulations also verify its effectiveness.

SS05: Layered Security over Radio Networks (SecNet) (Invited Papers)go to top

Room: Monticello Park
Chairs: Enrico Del Re (University of Florence, Italy), Lorenzo Mucchi (University of Florence, Italy), Luca Simone Ronga (CNIT, Italy)
4:30 Identification by means of a national ID card for wireless services
Victor Gayoso (Spanish National Research Council (CSIC) & Applied Physics Institute, Spain); Luis Hernández Encinas (Spanish National Research Council (CSIC) & Information Security Institute, Spain); Agustin Martin (Information Security Institute (ISI) & Spanish National Research Council (CSIC), Spain); Nacho Sánchez (Information Security Institute (ISI), Spain)
Wireless data communications have become an essential part of everyday life thanks to the ubiquity of Wi-Fi and mobile networks. Security issues are an important limitation factor in the deployment of wireless services, and to mitigate the emergence of new security weaknesses it is advisable to implement application level security on top of the standard security provided by the underlying technology. In this contribution we present an example about how to implement this additional level of security based on the usage of the Spanish national ID card and an application suitable for Android devices.
4:52 Intrinsic Secure Modulation for Pairing of Wireless Nodes
Lorenzo Mucchi (University of Florence, Italy); Luca Simone Ronga (CNIT, Italy); Enrico Del Re (University of Florence, Italy); Patrizio Marcocci (CNIT, University of Florence, Italy)
Due to the enormous spreading of applied wireless networks, security is actually one of the most important issues for telecommunications. One of the main issue in the field of securing wireless information exchanging is the initial common knowledge between source and destination. A shared secret is normally mandatory in order to decide the encryption (algorithm or code or key) of the information stream. It is usual to exchange this common a priori knowledge by using a "secure" channel. A new modulation technique, able to encrypt the radio signal without any a priori common secret between the two nodes, was previously proposed by the authors [1]-[3]. The information is modulated, at physical layer, by the thermal noise experienced by the link between two terminals. A loop scheme is designed for unique recovering of mutual information. This contribution improves the previous works by exploring the real robustness of the proposed technique against the presence of DOS warriors and impairment of the radio channel, considering also implementation details, such as the bit integration time. Both the case of passive and active attacks have also been implemented and simulated by using the Matlab Simulink.
5:15 Outage Capacity and Partial Secrecy for Energy Efficient Physical Layer Security in Gaussian Fading Channels
Ruolin Zhang (Stevens Institute of Technology, USA); Cristina Comaniciu (Stevens Institute of Technology, USA); H. Vincent Poor (Princeton University, USA)
The partial secrecy outage capacity for fading channels in wireless networks is investigated from an information theoretic perspective. An application layer characterization of physical layer secrecy is introduced to quantify the partial secrecy that can be achieved on a wireless transmission. Energy-secrecy tradeoffs are investigated based on outage capacity analysis and using our proposed partial secrecy metric. The outage probability is calculated under a long-term power constraint.
5:37 Non coherent demodulation of BPSK secure symbols
Fabio Zorzi (Italian Military Navy, Italy); Lorenzo Mucchi (University of Florence, Italy); Luca Simone Ronga (CNIT, Italy); Patrizio Marcocci (CNIT, University of Florence, Italy); Enrico Del Re (University of Florence, Italy); Marco Luise (University of Pisa & WISER srl, Italy)
From the communication channel and implementation aspects of communications, the transmission environment may be sufficiently degraded that acquiring and tracking a coherent demodulation reference signal is practically difficult. Coherent receivers require exact knowledge of the channel phase for optimum performance. Due to the difficult task of estimating the channel phase, non-coherent as well as differential detection is an attractive alternative to coherent detection. A conventional differential detector uses the signal received in the previous symbol interval as a phase reference for the received signal in the current interval. As long as the phase distortion introduced by channel varies slowly relative to the symbol rate, conventional differential detection will work quite well. This assumption is not always true, and, in addition, differentially coherent detection is based on the premise that there is no intersymbol interference (ISI) in the received signal. In this paper we present a new modulation technique which allows to transmit coherent secure symbols and demodulate them incoherently. The main advantages is the use of simpler receiver while still having information carried by the phase of the radio signal. In practise, an incoherent detector can be used, while having optimum performance as a coherent detector. No reference signal or symbol is needed to automatically compensate the total phase rotation at the receiver. It will be shown that the total phase rotation can be easily and accurately estimated (and compensated) at the receiver side, without relying on any phase reference from a transmitted pilot signal or from the received modulated signal.

Wednesday, June 26

10:30 AM - 12:00 PM (America/New_York)

CR1: Cognitive Radio 1go to top

Room: Central Park
10:30 Dynamic Channel Allocation Supporting Multi-Service over Cognitive Radio Networks
Xiuhe Zhang (Beijing University of Posts and Telecommunications, P.R. China); Li Guo (Beijing University of Posts and Telecommunications, P.R. China); Tao Song (Beijing University of Posts and Telecommunications, P.R. China); Wenjun Xu (Beijing University of Posts and Telecommunications, P.R. China); Yonghua Li (Beijing University of Posts and Telecommunications, P.R. China); Jiaru Lin (Beijing University of Posts and Telecommunications, P.R. China)
Multi-Service channel allocation supporting video service and data service simultaneously for frequency/time slotted cognitive radio (CR) networks is addressed. Our objective is to maximize the total network throughput while guaranteeing quality of service (QoS) requirements of both services. Meanwhile, the optimization problem is formulated into a non-linear integer programming problem. For this, first, we discuss its optimal solution and then we design two kinds of efficient heuristic algorithms. Numerical results reveal that our heuristic channel allocation algorithm with negotiation can achieve near-optimal throughput well satisfying the QoS requirements with simplicity.
11:00 A Cognitive Radio Relay Selection Scheme in Two-Tier Femtocell Networks
Xiaolong Zhao (Beijing University of Posts and Telecommunications, P.R. China); Tiejun Lv (Beijing University of Posts and Telecommunications, P.R. China)
The effective cross-tier interference (CTI) mitigation is a key technique for the macrocell and femtocell two-tier heterogeneous networks. In this paper, a cognitive radio relay selection (CRRS) scheme is proposed to improve the quality of service (QoS) of the femto-networks. On the one hand, for the macro-network, the scheme is intended to ensure the macrocell users can endure much more interference from the femtocell users. On the other hand, with respect to the femto-networks, the scheme can effectively improve the received signal strength relative to cross-tier macrocell interference of the femtocell users, so that the femtocell users can obtain a relative improvement in their Signal-to-Interference-plus-Noise-Ratio (SINR). Simulation results demonstrate that, compared with the existing works, the proposed scheme can not only increase the number of the successful femtocell users, but also improve the average SINR of the femtocell users.
11:30 Queuing Based Optimal Scheduling Mechanism for QoE provisioning in Cognitive Radio Relaying Network
Kun Wu (Beijing University of Posts and Telcommunications, P.R. China); Li Guo (Beijing University of Posts and Telecommunications, P.R. China); Hua Chen (Beijing University of Posts and Telecommunications, P.R. China); Yonghua Li (Beijing University of Posts and Telecommunications, P.R. China); Jiaru Lin (Beijing University of Posts and Telecommunications, P.R. China)
In cognitive radio network (CRN), secondary users (SU) can share the licensed spectrum with the primary users (PU). Compared with the traditional network, spectrum utilization in CRN will be greatly improved. In order to ensure the performance of SUs as well as PU, wireless relaying can be employed to improve the system capacity. Meanwhile, quality-of-experience (QoE) should be considered and provisioned in the relay scheduling scheme to ensure user experience and comprehensive network performance. In this paper, we studied a QoE provisioning mechanism for a queuing based optimal relay scheduling problem in CRN. We designed a QoE provisioning scheme with multiple optimized goals about higher capacity and lower packet loss probability. The simulation results showed that our mechanism could get a much better performance on packet loss with suboptimum system capacity. And it indicated that our mechanism could guarantee a better user experience through the specific QoS-QoE mapping models. So our mechanism can improve the network performance and user experience comprehensively.

RRM1: Radio Resource Management 1go to top

Room: Fairmount Park
10:30 Adaptive Load Balancing in LTE-Advanced Networks with Base Station Coordination
Vahid Noroozi (Iowa State University, USA); Aliazam Abbasfar (University of Tehran, Iran)
Load balancing(LB) in LTE-Advanced networks with base station coordination is investigated here. Base station coordination allows distributed base stations to act as a single multi-antenna transmitter by sharing the data to be transmitted via a high-capacity low-delay wired backbone. If all base stations coordinate their transmissions to all scheduled users, the interference can be mitigated significantly. An optimization problem is formulated here in which the constraints are physical resource limits and QoS demands and the goal is to minimize the percentage of unsatisfied users in the network and balance the load in the network. The complexity of the problem is analyzed, and suboptimal centralized algorithms are developed. Simulations are done and the results show that the proposed algorithms can significantly enhance the performance of the network by increasing the percentage of satisfied users in the network.
10:52 A Capacity Degradation Model for Sectorized FFR Networks
Tsang-Ling Sheu (National Sun Yat-Sen University, Kaohsiung, Taiwan)
This paper presents a capacity degradation model for sectorized cellular networks with FFR (Fractional Frequency Reuse). A sectorized FFR network (SFN) consists of a super group and a number of sectors. Since a super group in a cell employs the same frequency partition as the other super groups in the neighboring cells, inter-cell interferences may become serious when the radius of the super group is largely increased. In the worse case, the largely increasing inter-cell interferences will eventually degrade the overall system capacity. In this paper, Folded Normal Distribution (FND) of MSs is assumed in building the capacity degradation model. Numerical simulations show that by carefully adjusting the ratio between the radius of the super group and the radius of a cell, (i) an MS can receive the same capacity no matter where it is, and (ii) the maximum system capacity can be achieved.
11:15 Downlink Data Rate Gain Provided by a Mobile Relay for LTE-Advanced
Yangyang Chen (Telecom Bretagne, France); Xavier Lagrange (Institut Mines Telecom / Telecom Bretagne & IRISA, France)
In this paper, the data rate gain provided by a mobile relay deployed in a public transportation system is analyzed and calculated. The analysis is based on the Shannon formula modified for LTE. Through the analysis we get the conclusion that the data rate gain provided by mobile relay is not guaranteed in all cases. The penetration loss between outdoor and in-vehicle is a key factor to decide whether mobile relay could bring data rate gain into the system. Normally when UE is far away from donor eNodeB, the attached UE in relay case could achieve higher data rate than traditional case. Besides, the performance of the scenario with two antennas installed on vehicle is evaluated.
11:37 A Multi-Carrier Scheduling Algorithm for LTE-Advanced
Alexandru Vulpe (University Politehnica of Bucharest, Romania); Octavian Fratu (University Politehnica of Bucharest, Romania); Albena Mihovska (Aalborg Universitet, Denmark); Ramjee Prasad (Aalborg University, Denmark)
LTE-Advanced aims to provide a transmission bandwidth of 100 MHz by using Carrier Aggregation to aggregate LTE Rel. 8 carriers. In order to increase the system capacity, resource allocation becomes a very good tool, and, in the context of the existence of multiple Component Carriers in LTE-Advanced becomes a complex optimization problem. This paper proposes a Multi-Carrier Scheduling Algorithm that takes into account the user's QoS requirements and also targets the maximisation of the user throughput. The algorithm is evaluated in a scenario with both macro and femto Base Stations (i.e. a HetNet scenario) that respects the 3GPP specifications. Numerical results show that this algorithm has better performances than the traditional Round Robin and Proportionally Fair resource scheduling algorithms.

SS07: Technology Enablers for Future Ultra Dense Wireless Networksgo to top

Room: Monticello Park
Chairs: Angeliki Alexiou (University of Piraeus, Greece), Antonis G Gotsis (University of Piraeus, Greece)
10:30 Asynchronous Simultaneous Small Packet Transmission in Cellular Wireless System
Chandra Bontu (Research In Motion Limited, Canada); Jagadish Ghimire (University of Waterloo, Canada); Shalini Periyalwar (BlackBerry, Canada); Mark Pecen (BlackBerry, Canada)
Existing cellular wireless systems operate based on frame based protocol architecture are predominantly network controlled. A User Terminal (UT) is required to signal the network frequently to maintain its connectivity, and makes requests for uplink bandwidth to transmit packets. However, with the emerging applications, such as machine-to-machine (M2M), where small packets are transmitted sporadically, the bandwidth for signaling is more than the actual bandwidth to transmit the data. In this paper, we propose a novel connectionless uplink simultaneous accessing technique without the need of strict synchronization. UTs pick an uplink (UL) resource which is advertised by the network as a common radio resource for small packet transmissions and transmit the data packets. The data packet includes a preamble sequence and network assigned identity. The transmitted packets from each UT may not be in perfect synchronization with the UL system timing. The base station (BS) uses novel multi-user detection technique to separate these transmissions. Simulation results of the proposed method for an OFDM based system are shown be promising.
10:52 Advanced Power Control Techniques for Interference Mitigation in Dense 802.11 Networks
Oghenekome Oteri (InterDigital, Inc., USA); Pengfei Xia (Interdigital, USA); Frank LaSita (InterDigital Communications Corporation, USA); Robert L. Olesen (Interdigital Communications Corp., USA)
In this paper we propose an enhanced Transmit Power Control (TPC) scheme and a new fractional Carrier Sense Multiple Access with Collision Avoidance (F-CSMA/CA) scheme for use in a dense 802.11 network. The new schemes improve the energy normalized Media Access Control Goodput performance in networks with overlapping Basic Service Sets (OBSSs) by mitigating the interference effect using TPC and reducing interference generated during neighboring BSS-edge transmission using inter-cell coordination. The scheme works seamlessly with a CSMA/CA multiple access technique, and is suitable for evolution of future WLAN systems such as IEEE 802.11ah [4], and High Efficiency WiFi (HEW) [5]. Numerical results demonstrate an increase in the normalized goodput of up to 80% in downlink transmission and 100% in uplink transmission over existing schemes.
11:15 Optimal Cross-Tier Cooperation With Precoding in the Wireless Heterogeneous Networks
Rose Qingyang Hu (Utah State University, USA)
Wireless heterogeneous networks have emerged as a new paradigm to meet the fast increasing wireless capacity and coverage demands. Cooperative transmission and and Precoding are two promising techniques to further improve the network capacity and spectral efficiency. This talk presents an optimal cross-tier cooperative resource allocation scheme in a wireless heterogeneous network and explores the Tomlinson-Harashima Precoding (THP) in the physical layer to reduce the cross-tier interference. The objective is to maximize the aggregate proportional rates in the system. The scheme derives an asymptotically optimal solution for resource allocation by using a gradient descent based scheduling and KKT conditions for optimality. Simulation results demonstrate the system proportional fairness capacity gain of proposed cooperative resource allocation scheme.
11:37 Planning and Deploying Home Node B Clusters for Dense Wireless Networks
Pedro Santos (Instituto de Telecomunincacoes (IT), Portugal); Ana Dias (Vodafone, Portugal); Pedro Vieira (Instituto de Telecomunicações and ISEL, Portugal); André Martins (Instituto de Telecomunicações and Instituto Superior Técnico, Portugal); António J. Rodrigues (IT / Instituto Superior Técnico, Portugal)
This paper presents the followed strategy in the planning, integration and optimization of a group of Home Node Bs (HNBs) in an office environment. Firstly, a brief description of the HNB technology is set, being displayed the necessary characteristics for the operation of a cluster of femto-cells. Network planning is done through the use of the tool TEMS⃝R Transmitter, used in the field to determine the number of needed HNBs, as well as their location within the building. Finally, a configuration test is presented, focusing on the main parameters that enable installed HNBs to achieve the desired coverage area (higher than 95%).

1:00 PM - 2:30 PM (America/New_York)

CR2: Cognitive Radio 2go to top

Room: Central Park
Chair: Marcelo Portela Sousa (Federal University of Campina Grande, Brazil)
1:00 A database-assisted spectrum aggregation algorithm in TV White Spaces for Femtocells
Xiaoming Li (Beijing University of Posts and Telecommunications, P.R. China); Caili Guo (Beijing University of Posts and Telecommunications, P.R. China); Dongming Li (Beijing University of Posts and Telecommunications, P.R. China); Chunyan Feng (Beijing University of Posts and Telecommunications, P.R. China); Yuting Guo (Beijing University of Posts and Telecommunications, P.R. China)
In this paper, we research how to aggregate and allocate spectrum fragments of TVWS for Femto Base Stations (FBSs) in order to make full use of the nonuniform interference relationship between them. A database architecture control entity is introduced. Assisted by the entity, interference relationship between FBSs can be obtained in a cognitive manner and a distinctive graph coloring model considering spectrum aggregation is developed. We then propose the database-assisted spectrum aggregation algorithm (DSAA) which enables multiple FBSs to utilize the same spectrum fragments simultaneously in which they don't interfere with each other. Numerical results show that the proposed algorithm outperforms the traditional algorithms in the total access bandwidth of the Femtocell system and the accessing performance of the Femtocell network.
1:30 Energy Efficient Cooperative Multicast
Junxing Wang (Xi'an Jiaotong University, P.R. China); Xia Wang (Xi'an Jiaotong University, P.R. China); Zhigang Chen (Xi'an Jiaotong University, P.R. China); Yuan Yao (Xi'an JiaoTong University, P.R. China)
Aimed at the problem that system energy consumption of traditional cooperative multicast is becoming larger with the number of users increasing, a method of energy efficient relay selection is proposed. By using channel state information (CSI) among users, each user with poor channel condition selected a user, who had the best channel condition with it, as a relay, the selected user had decoded data correctly. Then two different approaches were taken to optimally allocate relays' power. Results show that energy efficient cooperation reduces energy consumption while ensuring the fairness compared to traditional cooperation; besides, energy efficient cooperation of improved power allocation reduces the computational complexity compared to energy efficiency cooperation based on approximate optimal relays power allocation.
2:00 Wireless Broadband Network on TVWS for Rural Areas: an Indian Perspective
Madhukar Deshmukh (Aalborg University, Denmark); Kishor Patil (Aalborg University, Denmark); Flemming Bjerge Frederiksen (Aalborg University, Denmark); Knud Erik Skouby (Aalborg University, Denmark); Ramjee Prasad (Aalborg University, Denmark)
Radio spectrum when used appropriately is an important catalyst for the flourishing of economic activities through broadband wireless services provision. The radio spectrum suitable for the propagation of wireless signals is a limited resource and hence requires optimal allocation as collectively dictated by regulatory, technical and market domains. The current global move to switch from analogue to digital TV has opened up an opportunity for the re-allocation of this valuable resource. In one way, spectrum bands once used for analogue TV broadcasting will be completely cleared-leaving a space for deploying new licensed wireless services, and in another way, digital television technology geographically interleaves spectrum bands to avoid interference between neighboring stations-leaving a space for deploying new unlicensed wireless services. The focus of the paper is to assess the availability of geographically interleaved spectrum, also known as television spectrum white spaces (TVWS) and proposing the wireless network scenarios for rural broadband connectivity.

RRM2: Radio Resource Management 2go to top

Room: Fairmount Park
1:00 A Novel Fuzzy Logic Based Vertical Handoff Decision Algorithm for Heterogeneous Wireless Networks
Peng Yang (Beijing University of Posts and Telecommunications, P.R. China); Yong Sun (Beijing University of Posts and Telecommunications, P.R. China); Chao Liu (Beijing University of Posts and Telecommunications, P.R. China); Wei Li (Beijing University of Posts and Telecommunications, P.R. China); Xiang Ming Wen (Beijing University of posts and telecommunications, P.R. China)
The next generation communication system will combine multiple wireless access networks, thus can provide mobile users with the best services. In these heterogeneous wireless networks, vertical handoff decision plays an important role to guarantee Always Best Connected (ABC) services and seamless mobility for mobile terminals. In this paper, we first introduce a speed-adaptive system discovery scheme before vertical handoff decision, which effectively improves the update rate of the candidate networks set. Then we propose a vertical handoff decision algorithm based on fuzzy logic with a pre-handoff decision method. Compared with the traditional RSS based handoff algorithm and sole fuzzy logic based handoff algorithm, the simulation results show that the proposed algorithm's performance is enhanced by reducing unnecessary handoffs, balancing the whole network resources and decreasing the probability of call blocking and dropping.
1:22 Seamless Service Handoff Based on Delaunay Triangulation for Mobile Cloud Computing
Xing Liu (Beijing University of Posts and Telecommunications, P.R. China); Zhen Yang (Beijing University of Posts and Telecommunications, P.R. China); Zhongwei Hu (Beijing University of Posts and Telecommunications, P.R. China); Chaowei Yuan (Beijing University of Posts and Telecommunications, P.R. China)
It is being envisaged that a wide variety of applications can be running on Mobile Cloud Computing (MCC) in the near future. The MCC suggests that the speed and direction of Mobile Terminal (MT) are unpredictable. That easily leads to large service latencies when MT handoff, and even results in the failure of time-critical applications for a long time. To address this issue, we propose a service handoff mechanism using the Delaunay triangulation (DTSHM). The DTSHM, which splits the network into Triangle topology by Delaunay triangulation, and accurately obtains MT's target access point. The master-standby service model is a key service platform for the DTSHM, which is composed of a master service point and two standby service points. Since the standby service points can in advance authenticate and cache the MT needed data packet, the MT can obtains lower service delay when do handoff. The simulation results and performance analysis show that the DTSHM works well.
1:45 An Adaptive and Reliable Integrated MAC mechanism for VANETs
Zishan Liu (Beijing University of Posts and Telecommunications, P.R. China); Rui Zou (Beijing University of Posts and Telecommunications, P.R. China); Hongtao Zhang (Beijing University of Posts and Telecommunications, P.R. China); Lin Zhang (Beijing University of Posts and Telecommunications, P.R. China)
In this paper, we propose an adaptive and reliable medium access control (MAC) mechanism for VANET. In this mechanism, the dwelling time ratio between the control channel and service channel can be dynamically adjusted according to the traffic density. Therefore the wireless resources can be fully utilized. The MAC mechanism supports the transmission of both emergency messages and beacon messages with different priorities over the control channel. It guarantees emergency messages access the channel in a minimum delay by giving them a strict highest priority. We verified our scheme through extensive simulations under the IEEE 802.11p setting, and the results demonstrate the superiority of our scheme in the reduction of transmission delay and improvement of throughput. To the best of our knowledge, this is the first attempt to design an integrate MAC mechanism by considering the access scheme, channel switching and priority setting concurrently.
2:07 Transmitted Power Formulation for the Implementation of Spectrum Aggregation in LTE-A over 800 MHz and 2 GHz Frequency Bands
Jessica Acevedo Flores (IT – Departamento de Engenharia Electromecânica- Universidade da Beira Interior, Portugal); Daniel Robalo (IT-DEM/University of Beira Interior, Portugal); Fernando J. Velez (University of Beira Interior & Instituto de Telecomunicações, Portugal)
This work proposes a formulation to calculate the transmitter power needed to cover cells of different sizes whilst maintaining the signal to interference-plus-noise ratio (SINR) constant, and near the maximum, for two long-term evolution-advanced (LTE-A) systems with an integrated common radio resource management (iCRRM) entity, in the context of spectrum aggregation (SA). The iCRRM entity is able to switch users between two LTE-A systems operating on non-contiguous frequency bands, 800 MHz and 2 GHz. The proposed formulation is based on the computation of the average received power and average co-channel interference in cellular topologies with frequency reuse pattern K = 3 whilst keeping the presence of coverage holes insignificant. The objective of applying this formulation in the dimensioning process is to save power for shorter coverage distances. We apply the COST-231 Hata path loss model and we corroborate the effect of the orthogonality factor in LTE's SINR.

SS08: Performance, Measurement, Evaluation and Security of Wireless and Mobile Networksgo to top

Room: Monticello Park
Chairs: Amrita Ghosal (B. C. Roy Engineering College, Durgapur, India), Subir Halder (Dr B. C. Roy Engineering College, Durgapur & Bengal Engineering and Science University, Shibpur, India)
1:00 Exploitation of Channel Division Multiple Access Diversity in UWB MB-OFDM System
Houda Chihi (ENIT, Tunisia)
In this paper, we investigate a new waveform for UWB systems obtained by the combination of MBOFDM and an innovative scheme that exploits the user's channels to guarantee multiple accesses called Channel Division Multiple Access (ChDMA).
1:18 An Intrusion Detection System for Cluster Based Wireless Sensor Networks
Deng Xue (Hunan University, P.R. China)
Dramatic advances in wireless sensor networks (WSNs) are paving the way for it's widely application. However, security issues have emerged. Compared with the general network, wireless sensor networks has its own characteristics. The most prominent point is the limited resource in WSNs. Such as energy, computation and communication capability. Therefore,security mechanism in wired network can not applied in WSNs directly. It is necessary to design an security system apply to WSNs. In this paper, we proposed a new intrusion detection system (IDS) which integrates the approach of nodes behavioral strategies and evidence theory. According to the deviation from the normal level of node's behavior, basic input vector of evidence is constructed. Meanwhile, the weight algorithm is applied to represent the importance of each behavior characteristic and revise evidences before synthesis. Finally, linked with evidence theory and judgment rules, we get the detection result of the evaluated node. The simulation results show that our approach is more effective in detecting malicious nodes with higher detection ratio and lower misdetection ratio compared with existing schemes.
1:36 CH-MAC: A Multi-channel MAC Protocol for Dynamic Spectrum Access Networks
Amitabh Mishra (Johns Hopkins University, USA); Gerald M Masson (Johns Hopkins University, USA); Taesung Kim (Johns Hopkins University, USA)
CH-MAC is a multi-channel medium access control protocol designed to work for multi-hop dynamic spectrum access networks. Its performance has been extensively evaluated with Ad hoc On Demand Distance Vector (AODV) routing and Destination Sequence Distance Vector (DSDV) protocols. Besides, CH-MAC protocol has several new architectural features such as channel evacuation and error recovery mechanisms that get activated when presence of an incumbent is detected on a channel in use that differ with existing protocols. We demonstrate that for static and dynamic network topologies, CH-MAC has better throughput and delay performance than well known multi-channel protocols.
1:54 Feasibility Analysis of Multi-Radio in DSRC Vehicular Networks
Lei Zhao (University of Alabama, USA); Xiaoyan Hong (University of Alabama, USA); Jingyuan Zhang (University of Alabama, USA); Yanping Zhang (Gonzaga University, USA); Qi Hao (University of Alabama, USA)
Dedicated Short Range Communications (DSRC) is a MAC layer and physical layer standard designed for vehicular networks. Multi-radio based is definitely able to improve DSRC performance. In multi-radio DSRC systems, the hand off latency will be reduced, and the bandwidth will increase. At the same time, the multi-radio system could improve DSRC spectrum usage, and reduce CSMA collisions. However, Multiple-radio in DSRC system has high requirements of Signal to Noise Ratio (SNR). Mutual coupling of antennas impacts the deployment of multi-radio DSRC system. In this paper, we prove that multi-radio DSRC is feasible in future vehicular networks. Through evaluating free-space path loss and optional adjacent channel rejections from the standard, we know multi-radio DSRC is possible. We analyze the SNR of modulations in DSRC Orthogonal frequency-division multiplexing (OFDM) system, and study the performance of BER according to SNR and FEC. Through analyzing BER, SNR, and measured spectrum density, we discuss the isolation requirement of antenna pair. We also analyze applicable decoupling methods and technologies to achieve the decoupling requirement. At least one decoupling method could meet the isolation requirement of multi-radio system and can be used in the future multi-radio DSRC networks. This point is supported by our experiment results in this paper.
2:12 Evaluation of Two Models for Securing SIP for Home Network Communications
Onur Demir (Yeditepe University, Turkey); Tolga Aktas (Netas, Turkey)
In this work, two different SIP communication models for smart home networks are suggested to meet the security requirements needed for verifying remote user's identity (authentication) and data privacy (confidentiality) of the connection. While the first method uses HTTP Digest Authentication for user registration security and IPSec tunnel for data confidentiality, the second method uses TLS for a secure authentication and SRTP in order to provide data confidentiality during the connection. SRTP key sharing is also provided by TLS before connection is established between a user and a home network. A pilot system is developed by using third party SIP stack implementation to observe the performance of the two alternatives. Results of these evaluations are presented.

2:30 PM - 4:00 PM (America/New_York)

SS10-1: Green Cognitive Radio Access Networksgo to top

Room: Berkshire
Chair: Adrian Popescu (Blekinge Institute of Technology, Sweden)
2:30 On Mobility Generated Signaling in Cognitive Radio Network Clusters
Alexandru Popescu (Blekinge Institute of Technology, Sweden); Yong Yao (Blekinge Institute of Technology, Sweden); Markus Fiedler (Blekinge Institute of Technology, Sweden)
The rapid migration towards wireless connectivity means that the radio spectrum must be efficiently utilized to conserve capacity and to avoid overcrowding, particularly in densely populated areas. Towards this goal, cognitive radio technology is a key concept. The basic idea is to allow unlicensed users access to licensed spectrum, under the condition that the interference perceived by the licensed users is minimal. A novel architecture designed and developed at the application layer has been suggested by researchers at Blekinge Institute of Technology for the management of cognitive radio networks. Emphasizing on signaling facilities in this architecture and common control channel dimensioning aspects, the paper reports on simulation results regarding node mobility for a particular network model. To reduce the energy consumption of mobile devices, innovative signaling strategies are a very important topic to consider in novel mobile systems architectures.
2:52 On Prioritized Spectrum Access in Cognitive Radio Networks with Imperfect Sensing
Yong Yao (Blekinge Institute of Technology, Sweden); Alexandru Popescu (Blekinge Institute of Technology, Sweden); Said Rutabayiro Ngoga (Blekinge Institute of Technology, Sweden); Adrian Popescu (Blekinge Institute of Technology, Sweden)
Cognitive Radio networks allow the unlicensed users to share the available spectrum opportunities. However, this demands for solving the problem of contention among multiple unlicensed user packets for transmission. In our paper, we consider the Opportunistic Spectrum Access model for packet transmission between two unlicensed users. We suggest a priority scheme for a unlicensed user to concurrently transmit different types of packets. Our scheme reserves a fixed number of queueing places in the buffer for the prioritized packets. We study the transmission performance under both the priority scheme and imperfect spectrum sensing, with respect to the blocking probabilities, average transmission delay and transmission throughput of unlicensed users packets. The Markov chain based numerical analysis is validated by simulation experiments. Our results show that the suggested priority scheme is able to enhance transmission throughput of unlicensed users packets, together with significant decreased average transmission delay and minor decreased total transmission throughput.
3:15 On Non-zero Secrecy Capacity and Outage Probability of Cognitive Radio Networks
Louis Sibomana (Blekinge Institute of Technology, Sweden); Hung Tran (National Institute of Education Management, Vietnam); Hans-Juergen Zepernick (Blekinge Institute of Technology, Sweden); Charles Kabiri (Blekinge Institute of Technology, Sweden)
In this paper, we consider a spectrum sharing cognitive radio network (CRN) in the presence of an eavesdropper (EAV) who illegally listens to the primary user (PU) communication. Under the PU outage and the secondary user (SU) peak transmit power constraints, the adaptive transmit power policy of the SU transmitter (SU-Tx) is obtained. Then, expressions for the probability of existence of a non-zero secrecy capacity of the primary network and the outage probability of the secondary network are derived. Numerical results are provided to investigate the impact of the SU-Tx peak transmit power, PU average transmit power and channel mean powers among users on the outage probability and probability of existence of a non-zero secrecy capacity. Our results illustrate that the probability of existence of a non-zero secrecy capacity strongly depends on the channel conditions among users and SU-Tx adaptive transmit power policy.
3:37 Ergodic Capacity of Cognitive Relay Networks over α-µ Fading Channels
Charles Kabiri (Blekinge Institute of Technology, Sweden); Hans-Juergen Zepernick (Blekinge Institute of Technology, Sweden); Hung Tran (National Institute of Education Management, Vietnam)
In this paper, we investigate the ergodic capacity for an underlay cognitive relay network over α-µ fading channels. In particular, we assume the channels to be independent non-identically distributed α-µ random variables and analyze the system performance subject to a peak interference power constraint. Numerical results are presented to evaluate the effect of fading parameters on the ergodic capacity of the system.

NMP1: Network Measurement and Performance 1go to top

Room: Central Park
2:30 Performance analysis of Dynamic Network Coding Scheme with Opportunistic Relay
Li SiHang (Beijing University of Posts and Telecommunications, P.R. China); Tiejun Lv (Beijing University of Posts and Telecommunications, P.R. China)
In this paper, we consider a dynamic network coding scheme with opportunistic relay (DNC-OR) for multiple sources multiple relays networks. In DNC-OR, all of the source transmit one's own data one by one. The selected relay dynamically applies network coding according to whether the source-destination channel from suffers an outage and sends the network-coded data to the destinations. Assume that (denoted as F) the data received from other resources by each destination are reliable, under assumption F and in case the assumption F does not exist, theoretical and numerical results show that DNC-OR can provide superior system outage performance to the network-coded cooperation scheme with dynamic coding mechanism (DC-NCC) proposed by Cong Peng and yields a full diversity order of N+1 , where N is the number of relay nodes. When the assumption F does not exist, we propose a dynamic network coding (DNC) scheme. The relay takes different actions according to different feedback message. For a network consist of a relay and two source-destination pairs, it is shown that DNC achieves superior diversity-multiplexing tradeoff to conventional cooperation(CC) by theoretical analysis and numerical results. Moreover, DNC-OR can significantly decrease system outage probability.
2:52 Network Parameters for Network Video Quality Assessment
Zhiming Shi (Beijing University of Posts and Telecommunications, P.R. China); Hui Liu (Beijing University of Posts and Telecommunications, P.R. China)
In this paper, we explore the impact of network parameters on perceptual quality of network video. First we present an experiment to measure the network parameters of video in the presence of different network bandwidth. Then we propose a no-reference video quality assessment method based on Media delivery index (MDI). M5' model tree, a data mining method, is good for segmental linearization of single-output multi-output system, was introduced to model the assessment method and its parameters. For all experimental data examined, our method yields high Pearson Correlation (higher than 0.95) with measured mean opinion score (MOS).
3:15 UNOTest: an Efficient Traffic Performance Test Platform in Heterogeneous Networks
Lin Zhang (Beijing University of Posts and Telecommunications, P.R. China); Yumei Wang (Beijing University of Posts and Telecommunications, P.R. China); Xihai Deng (Beijing University of Posts and Telecommunications, P.R. China); Yetao Yuan (Beijing University of Posts and Telecommunications, P.R. China); Gang Xu (Beijing University of Posts and Telecommunications, P.R. China)
Along with the rapid evolution of wireless communication standards, it poses great challenges on developing an efficient traffic performance test platform in heterogeneous network (HetNet) based on user-perceived experience. In this paper, we put forward a four-dimensional model theory and implemented the smart-phone based UNOTest platform for this purpose. We further carried on a large scale experiment within 2 months in 2 cities of China to study and analyzed the performance of HetNet including 3G, Wi-Fi and a trial TD-LTE network. Detailed case studies and analysis further reveal some insights in which operators or researchers would be interested.
3:37 Analyzing the Economic Impact of Fixed Relaying Deployment in a LTE Network
André Martins (Instituto de Telecomunicações and Instituto Superior Técnico, Portugal); António J. Rodrigues (IT / Instituto Superior Técnico, Portugal); Pedro Vieira (Instituto de Telecomunicações and ISEL, Portugal)
The current generation of mobile networks - Long Term Evolution (LTE) - allows the use of several new techniques, which will bring direct and visible performance benefits. This enables a better overall user experience and new features to Mobile Network Operators (MNOs). One of the most important new techniques will be Relaying. In addition to capacity and coverage gains, the usage of Relay Stations (RSs) minimizes the networks Capital Expenditure (CapEx) and Operating Expense (OpEx). In this paper, a comparison is made, from an economical perspective, between a LTE network composed entirely by evolved NodeBs (eNBs) and other scenarios which use additional RSs. The aim of the paper is to determine the conditions for a suitable eNB to RSs replacement, and the associated economical benefits.

RRM3: Radio Resource Management 3go to top

Room: Fairmount Park
2:30 Power Allocation for the PDCCH in LTE: A Way to Increase its Capacity in Realistic Deployments
David González G (Universitat Politecnica de Catalunya, Spain); Mario Garcia-Lozano (Universitat Politècnica de Catalunya, Spain); Silvia Ruiz Boqué (UPC, Spain)
In Long Term Evolution (LTE), the provision of Quality of Service (QoS) strongly depends on the efficiency with which control resources are allocated. Unfortunately, the design of the control channel, the Physical Downlink Control Channel (PDCCH), is not flexible enough to support Intercell Interference Coordination (ICIC) and hence, its degradation at cell edges (a well known issue in LTE) severely jeopardizes system performance. This problem acquires especial relevance in realistic large scale deployments where Signal to Interference plus Noise Ratio (SINR) distributions are much worse than the ones predicted by means of hexagonal layouts. Thus, this paper investigates the challenge of improving SINR levels at cell edges in order to enhance the performance of the PDCCH. The proposed scheme adjusts the power allocated to the PDCCH at each cell in order to improve SINR distributions (minimizing the usage of control resources) and, due to its multiobjective nature, it considers several perspectives of the problem. The results show that gains in the order of 25% can be obtained in severely interfered cells while overall energy savings are around 50%.
2:52 Power Control Algorithm with Active Link Protection for two-tier femtocell Networks
YuanBao Xie (Beijing University of Posts and Telecommunications, P.R. China); Wei Zheng (BUPT, P.R. China); Wei Li (Beijing University of Posts and Telecommunications, P.R. China); Liu Jingfang (Beijing University of Posts and Telecommunications, P.R. China); Xiangming Wen (Beijing University of Posts and Telecommunications, P.R. China)
Femtocell is a promising cost-effective technology for enhancing indoor coverage with high-rate data. However, femtocell base station (FBS) is controlled by terminal users, the bursty interference caused by femtocell will greatly degrade the Quality of Service (QoS) of macrocell users (MUEs), and even cause their communication interrupt. To address this problem, this paper investigates a suite of distributed power control algorithm with active link protection in two-tier femtocell networks. First, MUE collects the pilot signal power strength of FBSs at predetermined time interval to judge the presence of nearby femtocells. Second, MUE chooses an access channel (AC), and then initializes the protection margin of the signal to interference plus noise ratio (SINR) and transmitted power for this AC according to the above judgment. Finally, MUE and femtocell users (FUEs) update their transmitted power synchronously by the modified distributed power control based on active link protection (DPC/ALP) algorithm to maintain their QoS. Numerical examples show that the proposed scheme can be effectively applied in two-tier femtocell networks, and provide an acceptable admission speed and an effective QoS protection for both MUEs and FUEs.
3:15 Graph-coloring Based Resource Allocation Scheme in Relay Enhanced Cellular System
Jinlong Cao (Beijing University of Posts and Telecommunications, P.R. China); Tiankui Zhang (Beijing University of Posts and Telecommunications, P.R. China); Zhimin Zeng (Beijing University of Posts and Telecommunications, P.R. China); Dantong Liu (Queen Mary University of London, United Kingdom)
Graph-coloring based spectrum resource allocation scheme for relay enhanced cellular (REC) system is proposed in this paper. During the signal transmission process, each subframe is split into two equal time slots (TSs). In TS1, spectrum resource allocation between base station to relay node (BS-RN) link and base station to user equipment (BS-UE) link is studied, while spectrum resources in TS2 are allocated to BS-UE link and RN-UE link. In TS1, traffic load based resource allocation scheme is applied, where the number of resources allocated to BS-UE link or BS-RN link is according to the number of one-hop users and two-hop users. In TS2, co-channel interference is considered in the resource allocation process, which can mitigate strong interference between BS and UE, so as to achieve a higher data rate compared with conventional proportional fair (PF) resource allocation scheme. Simulation results show that the proposed scheme can obtain high average spectral efficiency as well as user fairness.
3:37 Interference-aware Relay Selection Scheme in Cooperative Relay Networks
Jinlong Cao (Beijing University of Posts and Telecommunications, P.R. China); Tiankui Zhang (Beijing University of Posts and Telecommunications, P.R. China); Zhimin Zeng (Beijing University of Posts and Telecommunications, P.R. China); Dantong Liu (Queen Mary University of London, United Kingdom)
Relay selection scheme with multiple source-destination pairs and multiple potential relays in cooperative relay networks considering co-channel interference (CCI) is proposed in this paper. In cooperative relay networks, which relay nodes are selected has great impact on the system performance. It is an optimization problem for selecting suitable relay nodes. The exhaustive search can solve this problem but the complexity will increase factorially with the network size, i.e., the number of source-destination pairs and the number of relays in the network. This paper proposes a novel quantum particle swarm optimization (QPSO) based relay selection scheme which can maximize the system throughput of the cooperative relay networks but has less computational complexity. Simulation results show that QPSO based relay selection scheme has the ability to search global optimal solution compared with other relay selection schemes in the literature.

SS09-1: Recent Advances in Spectrum Measurements and Modelling towards Flexible Spectrum Usagego to top

Room: Monticello Park
Chair: Liljana Gavrilovska (Ss Cyril and Methodius University - Skopje, Macedonia, the former Yugoslav Republic of)
2:30 Cooperative spectrum sensing based on noise power estimation
Valentin Rakovic (Ss. Cyril and Methodius University in Skopje, Macedonia, the former Yugoslav Republic of); Valentina Pavlovska (Skopje, Macedonia, the former Yugoslav Republic of); Vladimir Atanasovski (Ss Cyril and Methodius University in Skopje, Macedonia, the former Yugoslav Republic of); Liljana Gavrilovska (Ss Cyril and Methodius University - Skopje, Macedonia, the former Yugoslav Republic of)
The cooperative spectrum sensing process represents one of the key topics in the field of cognitive radio and dynamic spectrum access. This paper introduces the notion of Estimated Noise Power (ENP) in the case of the Equal Gain Combining and Majority Voting cooperative spectrum sensing techniques, and proves the benefit of its utilization. The performance analysis shows that the proposed approach increases the detection capabilities of the cooperative spectrum sensing techniques in terms of detection probability and ROC characteristics. Moreover, the results show that when utilizing the proposed approach, the cooperative spectrum sensing techniques increase their performance in terms of the average Bayesian risk.
2:52 Modulation Detection in Wireless Sensor Networks using Recurrence Plot Analysis
Angela Digulescu (Military Technical Academy, Romania); Elif Celik (University of South-East Europe LUMINA, Romania); Alexandru Serbanescu (Military Technical Academy, Bucharest, Romania); Octavian Fratu (University Politehnica of Bucharest, Romania); Simona Halunga (University POLITEHNICA of Bucharest, Romania)
Modulation detection, one of the most important objectives of a receiver in a communication system, is an intermediary step between its detection and demodulation. In this paper, it will be presented the recurrence method (RPA - Recurrence Plot Analysis) used for the detection of the type of the used modulation. For a wireless sensor network (WSN) which works with modulated signals, it will be presented the manner in which the RPA method can detect ASK, FSK, even PSK signals using its recurrence matrix or distance matrix [1]. Afterwards, we will highlight the OFDM detection using this method. The simulation results will confirm the importance of the RPA method.
3:15 Perspectives on Dynamic Spectrum Access Procedures in TV White Spaces
Alexandru Martian (University Politehnica of Bucharest, Romania); Alexandru Vulpe (University Politehnica of Bucharest, Romania); Razvan Craciunescu (University Politehnica Bucharest, Romania); Octavian Fratu (University Politehnica of Bucharest, Romania); Ion Marghescu (University Politehnica of Bucharest, Romania)
TV White Spaces (TVWS) are becoming more and more attractive for deploying high-speed broadband wireless communications in the freed spectrum left from the analog switchoff (ASO). In this respect, dynamic spectrum access (DSA) procedures are critical and have to rely on very accurate spectrum sensing techniques. This paper provides an overview of the current state of the art in dynamic spectrum access in TV white spaces and presents results of measurement campaigns for identifying TV white spaces in the city of Bucharest, before the ASO in Romania.
3:37 Potentials of TV and Radar Bands for Secondary Communications: Methods and Approaches
Pero Latkoski (Ss Cyril and Methodius University - Skopje, Macedonia, the former Yugoslav Republic of); Vladimir Atanasovski (Ss Cyril and Methodius University in Skopje, Macedonia, the former Yugoslav Republic of); Liljana Gavrilovska (Ss Cyril and Methodius University - Skopje, Macedonia, the former Yugoslav Republic of)
This paper aims to provide quantitative assessment results for the potentials of TV and radar bands for secondary communications in terms of secondary spectrum availability. In particular, its objectives are to present the developed methods and approaches for assessment of the secondary spectrum and to provide tangible results about its availability. The paper contains results of secondary spectrum in presence of multiple secondary WiFi-like users for two real world scenarios, involving two different primary communication networks: television (TV) broadcasting system and air traffic control (ATC) radar system. Detailed secondary access scenarios and scenario-dependent assessment methodologies from our previous work are adopted and elaborated here with necessary modifications to provide an overview of the findings and to draw generalized concussions.

4:30 PM - 6:00 PM (America/New_York)

SS10-2: Green Cognitive Radio Access Networksgo to top

Room: Berkshire
Chair: Adrian Popescu (Blekinge Institute of Technology, Sweden)
4:30 ENVIRAN: Energy Efficient Virtual Radio Access Networks
Adrian Popescu (Blekinge Institute of Technology, Sweden); Haesik Kim (VTT Technical Research Centre of Finland, Finland); Franco R. Davoli (University of Genoa & National Inter-University Consortium for Telecommunications (CNIT), Italy); Raúl Dopico López (Indra Sistemas S.A., Spain); Somsai Thao (Thales, France); Javier Del Ser (TECNALIA, Spain); Gerhard Wunder (Heinrich-Hertz-Institut, Germany)
ENVIRAN is a new research project aiming at the research, design and deployment of new architectural solutions for network virtualization and cognitive radio networks. The project is about developing and testing a new network architecture, to enable innovation through programmability and control of network functions and protocols. For doing this, we solve different technical challenges. These are about network virtualization, open architecture, reconfigurable software suite, virtual base station and decision support system. Another important part of the project is regarding the development of a cognitive virtualization platform, to test the new developed solutions. It is well known that cognitive radio technology is a key concept suggested to use the radio frequency spectrum in a more efficient manner than previous mobile networks. The difference in our case is that the cognition is used not only to provide better resource use for bandwidth but also for other categories of resources like energy/power consumption (by using, e.g., green routing, cooperative/relay networking), hardware utilization (in form of, e.g., virtual Base Stations, cognitive/reconfigurable wireless devices), reduce the cost of supporting the required QoS/QoE, new business models. Cognition and virtualization concepts are used to increase the efficiency of network management and resource utilization as well as to reduce the power consumption and the cost of supporting the expected QoS/QoE for communication. The expected research results will be tested, among others, in the world-wide virtual network PlanetLab.
4:52 Energy-based Anomaly Detection in Quality of Experience
Selim Ickin (Blekinge Institute of Technology, Sweden); Markus Fiedler (Blekinge Institute of Technology, Sweden); Katarzyna Wac (University of Geneva & Quality of Life group, Switzerland)
Subjective performance of smartphone-based high bandwidth- and energy-demanding applications and services such as video streaming, are highly influenced by the temporal impairments perceived by the user at the user interface; and the application's energy consumption patterns. Therefore, we study the influence of the anomalies detected by objective measurements from the user interface and the network-level, on the power consumption during video streaming on the smartphone. In this paper, we study the inter-frame time metric, i.e., the time gap between two consecutive displayed pictures at the user interface; the inter-packet time and the initial signaling duration at the network-level; and the instantaneous power consumption at the power supply of the smartphone. We conduct experiments on the VLC media player, while streaming video via local-storage; via 3G using RTSP protocol; and via 3G using HTTP protocol. We show that the anomalies detected at the instantaneous power consumption reveals the anomalies at the user interface and the network-level.
5:15 Energy-Efficient Cooperative Spectrum Sensing with Relay Switching Based on Decision Variables for Cognitive Radio
Yawgeng A. Chau (Yuan-Ze University, Taiwan)
Two schemes of energy-efficient cooperative spectrum sensing with relay switching over Rayleigh fading channels are proposed and analyzed for cognitive radio (CR). With relay switching, to save the power and transmission resource of the relays, not all available relays are activated all the time. In the first scheme, when relaying is activated, a switch-and-test (SWT) policy based on the energy received from the relaying path is used. To enhance the detection performance of SWT, in the second scheme, a switch-and-selection-test (SST) policy is considered. In both schemes, energy detection is employed for spectrum sensing. Both SWT and SST schemes integrate the relay switching and spectrum sensing into one step, which further saves the power and time of relay processing. The corresponding probabilities of false alarm and correct detection are derived. Numerical results are presented for performance illustration and comparisons.
5:37 Optimum Transmit Beamforming Scheme for Underlay Cognitive Radio Networks
Sudeep Bhattarai (Tennessee State University, USA); Liang Hong (Tennessee State University, USA); Sachin Shetty (Tennessee State University, USA)
Cognitive Radio (CR) is a promising intelligent technology to increase the spectral efficiency by permitting Primary Users (PU) and Secondary Users (SU) to share the radio spectrum. This paper proposes an optimum transmit beamforming scheme that allows multiple SU, stationary and/or moving, to co-exist with a stationary PU. With knowledge of channel information only between the secondary transmitter and stationary users (but not moving SU), the optimization problem is formulated to ensure maximum transmission power towards the desired SU, while constraining the interference to PU. The transmission power is constant in an area of angles when the SU is not static. The interference to PU can be forced to zero. By first converting the problem into convex form, the optimum solution is obtained through second-order cone programming. Simulation results show that the probability of successful transmission between SU is significantly boosted without degrading the communication of the PU. Simulation results also show that the proposed scheme maintains uniform transmission power for moving SU within a desired range of directions, while nulling the interference to PU and other SU.

NMP2: Network Measurement and Performance 2go to top

Room: Central Park
4:30 On the Benefits of Converged Next Generation Network Architecture
Radostina Gercheva (Aalborg University, Denmark); Sri Hanuma Chitti (Aalborg University, Denmark); Neeli Rashmi Prasad (Center for TeleInFrastructure (CTIF), Denmark); Ramjee Prasad (Aalborg University, Denmark)
The increase in number of mobile devices and in the mobile internet traffic is forcing the backhaul network architecture to undergo radical transformation. It is becoming hard to meet the demands of latency and service quality requirements of next generation backhaul networks by the current practices with multiple autonomous systems. In this paper, a novel backhaul architecture is proposed with single autonomous system that can help to overcome the problem with the exhaustion of AS number space, and at the same time providing better performance, simplification, reliability, and scalability, so the mobile backhaul can handle the future generation of services efficiently. An experimental setup is proposed in this paper to evaluate the results. Latency and QoS are the main evaluation parameters for the suggested network architecture.
4:52 Analysis of Coverage Range Expansion in Closed Access Cognitive Femtocell Networks
Faisal Tariq (The Open University, United Kingdom); Laurence S Dooley (Open University, United Kingdom); Adrian Poulton (The Open University, United Kingdom)
Femtocells are low-power nodes which aim to extend high data-rate wireless services in indoor environments, where typically the radio signal quality is poor in conventional cellular systems. While low power operation allows more frequent spectrum reuse and significant improvement in network capacity, it also suffers from frequent handoffs between the macro and femtocell due to the short distances involved. Even users with low mobility may move out of the coverage for short period which can potentially generate considerable redundant control data for handover management. An alternative is to apply handover bias which artificially expands the coverage range of a femtocell to keep a user connected to a femtocell access point (FAP). This eliminates the handover problem or ping pong effect, but at the cost of reduced throughput. This paper proposes an Enhanced Virtual Cluster Formation (EVCF) algorithm that allows the coverage range of the femtocells to be expanded. The impact of FAP coverage expansion on system performance of closed access femtocell networks for various FAP deployments has been analysed. The performance of the EVCF is compared to a random resource allocation system with similar range expansion capability. Results reveal that while FAP range extension inevitably decreases the signal to interference plus noise ratio (SINR) and corresponding throughput, the resultant degradation can be minimised by adopting the EVCF model with a commensurate enhancement in the system quality-of-service (QoS) provision.
5:15 Power Consumption Testing and Optimization for Mobile Router based on Data Aggregation and Compression
Yumei Wang (Beijing University of Posts and Telecommunications, P.R. China); Lin Zhang (Beijing University of Posts and Telecommunications, P.R. China); Hongyu An (Beijing University of Posts and Telecommunications, P.R. China); Bin Xu (Beijing University of Posts and Telecommunications, P.R. China); Geng Xi (Beijing University of Posts and Telecommunications, P.R. China)
Mobile router is a kind of network entity that can bridge a group of mobile stations to the Internet via a two-hop wireless relay. The running time of current commercial mobile router is quite unsatisfactory, which is typically 3~4 hours between charges. In this paper, we assess the power consumption of different parts (i.e. the main board and the 3G/WLAN wireless interface) of a mobile router based on our testbed built on Pandaboard ES development board, which is called MoRo hereinafter. The testing results show that the wireless communication occupies more than one-third of the total power consumption of MoRo and the unmatched data rates between the two wireless interfaces of MoRo result in unnecessary power consumption on the local higher-rate wireless interface due to its intermittent transmission. Thus, we propose to cache the downloaded application data for one request at the mobile router, aggregate (i.e. store and forward) and compress the data (e.g. different FTP packets of a file, or different files of a web page), and then forward the bulk data with the size below a threshold to the mobile terminal via the local higher-rate interface all at once. The power testing results indicate that up to 18.4% reduction of the total energy consumption can be achieved.
5:37 Non-saturated and Saturated Throughput Analysis for IEEE 802.11e EDCA Multi-hop Networks
Yuta Shimoyamada (Chiba University, Japan); Hiroo Sekiya (Chiba University, Japan); Kosuke Sanada (Chiba University, Japan)
This paper presents first-step analytical expressions of non-saturated and saturated throughput for IEEE 802.11e EDCA multi-hop string-topology networks. Internal collisions in each node, concurrent transmission collisions among nodes, differences of CWmin and CWmax among ACs, and effects of contention zone are considered. By comparisons with simulation results, the validities of analytical expressions are confirmed.

AS: Applications and Servicesgo to top

Room: Fairmount Park
4:30 Characterizing Smartphone Traffic with MapReduce
Yang Jie (Beijing University of Posts and Telecommunications, P.R. China); Shuo Zhang (Beijing University of Posts and Telecommunications, P.R. China); Xinyu Zhang (Beijing University of Posts and Telecommunications, P.R. China); Jun Liu, Dr. (Beijing University of Posts and Telecommunications, P.R. China); Gang Cheng (Microsoft Corporation, P.R. China)
With the demand of increasing revenue by attracting customers consuming mobile internet services, traffic monitoring and analysis become more critical on network management and service provisioning for operators and ISPs. At the same time, the rapid growing number of smartphone clients led to more complexity and explosive mobile Internet traffic. It makes traditional traffic analyzing methods face challenge of dealing with huge amount of data. In this paper, we propose and implement a distributed computing system which aims to perform high-speed data-intensive network traffic analyses by leveraging MapReduce programming model. Running on this efficient system, we summarize characteristics of smartphone mobile internet traffic by analyzing massive real data which is captured from a living UMTS network of a major service provider of China. Our analysis is crucial for cellular providers to anticipate usage patterns and future traffic growths.
5:00 Detecting the Core Network of Microblog Using Snowball Sampling
Chuang Zhang (Beijing University of Posts and Telecommunications, P.R. China)
Different with other social network services, users in microblog are connected by directed and asymmetric relations. The users can follow any others as they liked. According to the influence offline or online, some users, who are superstars, have many followers and possess dominant positions in the networks. These users form the core of the networks, which controls the information flow in the complex systems. In practice, with many technical and privacy restrictions, collecting superstars' information and acquiring representative network samples is a big challenge for studying the critical structures of a large directed network. This paper studies the effectiveness of snowball sampling in recovering the core nodes in directed networks. We constructed a network of 35 million users of the most influential microblog in China- Sina Weibo,, and performed snowball sampling with various strategies of choosing sampling seeds, waves, and branches. The results reveal the systematic biases of different sampling schemes. Although snowball sampling with a few seeds and waves can cover most of superstars in the network, their indegree distribution is significantly affected by the sample dependency, which is introduced by the sampling strategies.
5:30 Peer Management for iTrust over Wi-Fi Direct
Isai Michel Lombera (University of California, Santa Barbara, USA); Louise E. Moser (University of California, Santa Barbara, USA); Michael Melliar-Smith (University of California, Santa Barbara, USA); Yung-Ting Chuang (University of California, Santa Barbara, USA)
This paper describes peer management for the iTrust peer-to-peer search and retrieval system using Wi-Fi Direct in a mobile ad-hoc network. Specifically, we discuss how to acquire MAC addresses and associate peers with IP addresses in order to discover, connect and transfer data using Wi-Fi Direct on Android mobile devices. An Android device with Wi-Fi Direct hardware capabilities can automatically create and maintain a mobile ad-hoc network with nearby, similarly configured mobile devices to share information. We present the fundamental concept of the iTrust mobile ad-hoc network, the capabilities and limitations of Wi-Fi Direct on Android, and our novel algorithm for managing peer connections. Finally, we discuss limitations of the algorithm and how certain parameters within Android and iTrust may be adjusted for optimal performance.

SS09-2: Recent Advances in Spectrum Measurements and Modelling towards Flexible Spectrum Usagego to top

Room: Monticello Park
Chair: Liljana Gavrilovska (Ss Cyril and Methodius University - Skopje, Macedonia, the former Yugoslav Republic of)
4:30 Comparison of Longley-Rice, ITM and ITWOM propagation models for DTV and FM Broadcasting
Stylianos Kasampalis (Brunel University - London - UK, Greece); Pavlos Lazaridis (Alexander Technological Educational Institute of Thessaloniki, Greece); Zaharias D Zaharis (Telecommunications Centre, Aristotle University of Thessaloniki, Greece); Aristotelis Bizopoulos (Alexander Technological Educational Institute of Thessaloniki, Greece); Spiridon Zettas (Brunel University, Greece); John Cosmas (Brunel University, United Kingdom)
With the rapid deployment of digital TV, there is an increasing need for accurate point-to-area prediction tools. There is a great deal of propagation models for coverage prediction of DTV. Some of them are pure empirical models, and others are mixed, empirical-analytical models, based on measurement campaigns and electromagnetic theory. The aim of this paper is to compare accurate measurements taken by a Rohde & Schwarz FSH-3 portable spectrum analyzer and precision antennas (biconical and log-periodic), with simulation results derived from coverage prediction models, like the NTIA-ITS Longley-Rice model, the ITM (Irregular Terrain Model) using the 3-arc-second SRTM (Satellite Radar Topography Mission) data that is available freely, and the newer ITWOM (Irregular Terrain with Obstructions Model) model which combines equations from ITU-R P.1546 model with Beer's law and Snell's law. Furthermore, measurements for analog FM broadcasting are compared to predictions from the above mentioned models.
4:52 Channel estimation for OFDM systems based on a time domain pilot averaging scheme
Spiridon Zettas (Brunel University, Greece); Stylianos Kasampalis (Brunel University - London - UK, Greece); Pavlos Lazaridis (Alexander Technological Educational Institute of Thessaloniki, Greece); Zaharias D Zaharis (Telecommunications Centre, Aristotle University of Thessaloniki, Greece); John Cosmas (Brunel University, United Kingdom)
In modern wireless communications there is an increasing need for higher data rates. Modern Digital TV (DTV), like Digital Video Broadcasting Terrestrial (DVB-T/T2), DVB Handheld (DVB-H), Digital Audio Broadcasting (DAB), 4th Generation (4G) mobile telephony known as Long Term Evolution (LTE) and IEEE 802.11a/b/g/n for wireless LAN (WLAN) are typical applications where high data rates are needed. The adaptation of Orthogonal Division Multiplexing (OFDM), which is a multicarrier modulation, helped to achieve high data rates while the transmission system became more robust against multipath fading, which traditional single carrier systems failed to handle effectively. The OFDM system divides the available bandwidth into a large number of narrow band sub-channels, which have their own respective subcarrier and each one of them can considered as a flat fading channel. In order to have reliable reception of the transmitted data, the knowledge of the channel impulse response is important. In this paper we are focusing on pilot aided channel estimation. A novel channel estimator is proposed to eliminate multipath and noise effects assuming Additive White Gaussian Noise (AWGN) and considering that the channel suffers only from slow fading effects. In this case, the channel can be considered to be invariant in time over an interval of the few last OFDM received symbols. Averaging over the last received OFDM symbols leads to reduced noise at the receiver. The benefits of the proposed estimator are its very simple implementation, its good performance for slowly time-varying channels and its application in devices with limited available memory and computational capabilities. In addition, it can be used for battery saving in handheld devices, due to the reduced complexity.
5:15 TV white spectrum in India
Purnendu Shekhar Mani Tripathi (Aalborg University & Centre for Teleinfrastructure (CTIF), Denmark)
TV band is a precious band from the coverage point. A large portion of 1 GHz sub band has been allocated for TV broadcasting. It has been found that a large chunk of this TV band is unutilized at a given location and it is wastage of precious natural resource. The idea about exploitation of idle TV spectrum at any location is getting strong after emergence of cognitive radio technology and dynamic spectrum access. Most of countries has developed regulatory framework for unlicensed application in TV white space. The TV band has not yet opened in India for unlicensed usage. This paper gives an idea about present scenario of allocation of TV spectrum in India and its utilisation including requisite regulatory framework.
5:37 Cognitive Access to TVWS in India:TV Spectrum Occupancy and Wireless Broadband for Rural Areas
Kishor Patil (Aalborg University, Denmark); Knud Erik Skouby (Aalborg University, Denmark); Ramjee Prasad (Aalborg University, Denmark)
The digital transition of TV transmission will make available some TV frequencies which are to be geographically unused called as TV White Spaces. The important regulatory trend in the context of Dynamic Spectrum Access (DSA) is the Cognitive access of TV white Spaces. In this context, we have performed spectrum measurement of TV band in Pune, India. Our result shows poor spectrum utilization in TV band and good potential for Cognitive radio operation. Digital switchover in India will generate golden opportunity for empowering rural India. As majority of India's population lives in rural part of India, we have proposed wireless broadband access to rural areas using TVWSs. This will help in bridging the digital divide by offering governance, banking and health services online in rural area.

Thursday, June 27

10:30 AM - 12:00 PM (America/New_York)

MULTI: Multimediago to top

Room: Central Park
10:30 A Novel Temporal Error Concealment Framework for H.264 over Wireless Networks
Yi Wang (Beijing University of Posts and Telecommunications, P.R. China); Xiaoqiang Guo (Academy of Broadcasting Science, P.R. China); Ye Feng (Beijing Unversity of Posts and Telecommunications, P.R. China); Aidong Men (Beijing University of Posts and Telecommunications, P.R. China); Bo Yang (Beijing University of Posts and Telecommunications, P.R. China)
Video transmission over wireless networks suffers from packet loss due to either packet drop or fading-induced bit errors. Temporal error concealment (EC) is an useful video coding technique to recover the errors in video transmission. In this paper, we propose a novel framework for temporal EC for H.264 over wireless networks. The proposed framework combines the properties of Inter Mode in H.264 Inter frame and motion inpainting in the computer vision community. In the framework, modes of the correctly received surrounding blocks of the corrupted macroblocks (MBs) are checked first. Then, according to the modes, we divide into four EC methods to conceal the corrupted MBs , which include 4×4 blocks motion inpainting, 8×8 blocks motion inpainting, the boundary matching algorithm and zero motion vector (MV) based EC method. Experimental results on several videos show that the proposed method has good objective and subjective video quality performance, whilst also being with low computation cost.
11:00 Multi-Frame Rate Based Multiple-Model Training for Robust Speaker Identification of Disguised Voice
Swati Prasad (Aalborg University, Denmark); Zheng-Hua Tan (Aalborg University, Denmark); Ramjee Prasad (Aalborg University, Denmark)
Speaker identification systems are prone to attack when voice disguise is adopted by the user. To address this issue,our paper studies the effect of using different frame rates on the accuracy of the speaker identification system for disguised voice.In addition, a multi-frame rate based multiple-model training method is proposed. The experimental results show the superior performance of the proposed method compared to the commonly used single frame rate method for three types of disguised voice taken from the CHAINS corpus.
11:30 Visual Attention Modeling for Video Quality Assessment With Structural Similarity
Bin Fu (Beijing University of Posts and Telecommunications, P.R. China); Zhaoming Lu (BUPT, P.R. China); Xiangming Wen (BUPT, P.R. China); Luhan Wang (Beijing University of Posts and Telecommunications, P.R. China); Hua Shao (Beijing University of Posts and Telecommunications, P.R. China)
Saliency map demonstrates the regions where the human eye will typically focus, and the key step of proposed video assessment metrics is to generate saliency map of each frame over the video sequence. However, it remains a challenge of the accuracy of saliency detection. In this paper, a lightweight multiscale approach is presented to extract spatial and temporal attention. The final saliency map is obtained by integrating two attention models. Spatial attention modeling takes into account the characteristics of the human visual system (HVS). In temporal attention modeling, we use a novel multiscale approach method to extract motion feature, which is based on segmentation of objects in video sequence. As the temporal pooling schemes used in existing video quality assessment are only direct average or Minkowski summation of image quality scores over the video sequence, we use a procedure which takes HVS mechanism on video sequence into account adequately. In addition, the results demonstrate that the proposed method in this paper can improve the performance of video quality metrics obviously.

PLCCM1: Physical layer, channel coding and modulation 1go to top

Room: Fairmount Park
10:30 Enhanced CSI Feedback and Update for Downlink CoMP Joint Transmission
Xiang Yun (DOCOMO Beijing Communications Laboratories Co., Ltd., P.R. China); Yu Jiang (DoCoMo Beijing Labs, P.R. China); Lan Chen (DOCOMO Beijing Communication Laboratories Co., Ltd, P.R. China); Satoshi Nagata (NTT DoCoMo, Inc., Japan)
Joint Transmission (JT), through which inter-cell interference could be utilized to enhance the desired signal, is regarded as a promising coordinated multi-point (CoMP) transmission scheme to improve the cell-edge user performance. To achieve coherent CoMP JT, besides per-point channel state information (CSI), additional channel information is necessary such as the inter-point phase, aggregated channel quality indicator (CQI), and aggregated precoding matrix indicator (PMI). Due to the feedback overhead, not all of these types of information can be obtained. In this paper, under the assumption that the inter-point phase information is allowed for additional feedback, we propose a new inter-point phase selection method and a new CQI update method that jointly consider the JT combining gains and CQI update accuracy. Based on the system level simulation evaluation, the proposed methods achieve better cell-edge user throughput than JT scheme with conventional CSI feedback and CQI update.
10:48 Analysis and Modeling of 2.3 GHz Near-Ground Channel Based on Broadband Channel Measurements
Min Zhao (Beijing University of Posts and Telecommunications, P.R. China); Muqing Wu (BUPT, P.R. China); Yanzhi Sun (Beijing University of Posts and Telecommunications & Laboratory of Network System Architecture and Convergence, P.R. China); Deshui Yu (Beijing University of Posts and Telecommunications, P.R. China)
The increasing interest that has been drawn to wireless sensor network technology is therefore required accurate analysis and modeling of wideband near-ground channel in all relevant environments and scenarios. Key characteristics of near-ground channels are low antenna height, short communication range, the dominated line-of-sight component and the reflection of the ground. Using slippage correlation algorithm, six typical indoor and outdoor scenarios are first analyzed to compare the system performances in 2.28-2.32 GHz, with antenna height and scenario as only variables. This paper first presents comprehensive analyzed results of the statistical channel properties, including both the small-scale and large-scale fading parameters. In particular, channel impulse response, power delay profile, the RMS delay spread, the mean delay, the number of discrete multipath components are extracted, evaluated and reported. The proposed path loss model is applicable to different scenarios and benefits link budget of the system. Furthermore, the relationship between channel attenuation and antenna height, as well as the specific impact on channel characteristics by different scenarios are concluded. All these results promote the evaluation and verification of near-ground wideband communication systems.
11:06 A Solution for Improving Performance of OFDM based Simple Cooperative Relaying
Ugljesa Urosevic (Faculty of Electrical Engineering, University of Montenegro, Montenegro); Zoran Veljovic (University of Montenegro, Montenegro); Milica Pejanovic-Djurisic (University of Montenegro & Centre for Telecommunications, Montenegro)
In this paper we present a solution for improving performance of orthogonal frequency division multiplexing (OFDM) based simple cooperative relaying which is used for achieving 4th order diversity. The proposed scheme is compared with OFDM based simple cooperative relaying scheme with virtual orthogonal space time block coding (OSTBC). Each of these two schemes includes one base station with two antennas, two relay stations with a single antenna and one mobile station with a single antenna. The aim of the proposed solution is to improve bit error rate (BER) performance and code rate of the OFDM based cooperative scheme with virtual OSTBC. It is shown that the proposed scheme obviously outperforms performance of simple cooperative relaying schemes with virtual OSTBC.
11:24 Complete Analytical Model of Dual-Hop Relay System over Ricean Fading Channels
Maja Ilic-Delibasic (University of Montenegro, Montenegro); Milica Pejanovic-Djurisic (University of Montenegro & Centre for Telecommunications, Montenegro)
In this paper we present a complete analytical model, including closed form expressions for probability density function (PDF), cumulative distribution function (CDF) and moment generating function (MGF) of total received SNR (signal-to-noise ratio) for dual hop amplify-and-forward relay transmission over non-identical Ricean fading channels. Furthermore, adequate closed form expressions for average bit error rate (BER) and outage probability (OP) are derived. Numerical and simulation results confirm the validity of the proposed analytical model. Additionally, we analyzed the impact of unbalanced SNRs of the two hops on the error performance of the considered relay system.
11:42 Nonlinear Precoding Scheme for the Downlink of Multiuser MIMO Cognitive Radio Networks
Hui Lu (Beijing University of Posts and Telecommunications, P.R. China); Li Guo (Beijing University of Posts and Telecommunications, P.R. China); Jiaru Lin (Beijing University of Posts and Telecommunications, P.R. China); Yonghua Li (Beijing University of Posts and Telecommunications, P.R. China)
This paper aims to solve the problem that the cognitive base station (CBS) minimizes the BER and maximizes the sum capacity in the condition of the interference constraint for the primary users (PUs). The Tomlinson-Harashima precoding (THP) schemes have widely used in the general network and matrix decomposition is an important tool in the THP. The main contribution of this paper is applying three kinds of THP algorithm in the multiple user multi-input multi-output (MU-MIMO) system to cognitive radio (CR) network by using matrix decomposition. The Computer simulations of these modified algorithm shows that cognitive minimum mean square error block diagonal Tomlinson-Harashima precoding (CR-MMSE-BD-THP) has better performance.

1:00 PM - 2:30 PM (America/New_York)

IP1: Invited papersgo to top

Room: Central Park
1:00 Analysis of Design Requirements for Electronic Tags from a Business Viewpoint
Izabella V Lokshina (SUNY Oneonta, USA); Wade Thomas (SUNY Oneonta, USA)
The significance, which businesses and governments have placed on the RFID and NFC technologies in electronic article surveillance, the cashless payment systems from credit cards and public transportation tickets to the consumer devices, healthcare, and e-government, involves reviewing requirements for the electronic tags. This paper defines the electronic tag life cycle that follows the product life cycle, considers representative business processes and interacting business entities, classifies the electronic tag usage methods, identifies the electronic tag risks, and summarizes the design requirements for the electronic tags from a business viewpoint to be considered by the RFID and NFC developers.
1:22 An Efficient Data Locality Driven Task Scheduling Algorithm for Cloud Computing
Dhananjay Kumar Singh (University of Pune & Sinhgad Institute of Technology, India)
Large scale data processing is increasingly common in Cloud Computing systems like Hadoop, Mapreduce etc. In these systems, files are split into many small blocks and all blocks are replicated over several servers. To process files efficiently, each job is divided into many tasks and each task is allocated to a server to deal with a file block. Because network bandwidth is a scarce resource in these systems. Enhancing task data locality (placing tasks on servers that contain their input blocks) is crucial for the job completion time. Although there have been many approaches on improving data locality, most of them either are greedy and ignore global optimization, or suffer from high computation complexity. To address these problems, we propose a heuristic task scheduling algorithm in which an initial task allocation will be produced at first, and then the job completion time can be reduced gradually by tuning the initial task allocation. By taking a global view, the algorithm can adjust data locality dynamically according to network state and cluster workload.
1:45 Disaster-resilient wireless mesh network -Experimental test-bed and demonstration-
Ryu Miura (NICT, Japan); Masugi Inoue (National Institute of Information and Communications Technology, Japan); Yasunori Owada (National Institute of Information and Communications Technology, Japan); Kenichi Takizawa (National Institute of Information and Communications Technology, Japan); Fumie Ono (National Institute of Information and Communications Technology, Japan); Mikio Suzuki (National Institute of Information and Communications Technology, Japan); Hiroyuki Tsuji (NICT, Japan); Kiyoshi Hamaguchi (NICT, Japan)
Based on the lessons learned from the crisis of Great East Japan Earthquake, we started R&D on the disaster-resilient wireless network, which consists of a de-centralized mesh architecture using WLAN in 5.6GHz band for mesh links and WLAN in 2.4 GHz band for access links. The mesh nodes have cash memories synchronized to each other to manage user and routing information, providing various messaging services even if the connection to the Internet or core networks gets lost under disasters. The test-bed also provides relay networks by small unmanned aerial systems (UAS) and a satellite, in order to connect remotely located nodes or to get a connection to isolated areas caused by the infrastructure damages under disasters. A test-bed to evaluate and demonstrate the performance of this concept was developed in the campus of Tohoku University, Sendai, Japan, and a demonstration test was conducted in March 2013. In the test-bed, users access the network using their own smart phones or PCs with WLAN, or their own IC card via street-side signage stations integrated to LED town lights.
2:07 Air-to-air Radio Channel Measurement at 2.3 GHz for Unmanned Aircraft Services
Kenichi Takizawa (National Institute of Information and Communications Technology, Japan); Fumie Ono (National Institute of Information and Communications Technology, Japan); Hiroyuki Tsuji (NICT, Japan); Ryu Miura (NICT, Japan)
This paper presents a summary of a measurement campaign regarding radio propagation characteristics between airplanes based on a usage scenario of unmanned aircraft services (UASs) for disaster recovery. In order to reveal the characteristics air-to-air (A2A) links, the measurement campaign has been conducted in Hawaii, by using two small manned airplanes, through a 20-MHz bandwidth OFDM signal designed to this measurement at 2.3 GHz. The OFDM signal is continuously transmitted from one airplane, and at the other airplane signals received is repeatedly recorded. The recorded signals are utilized to calculate channel impulse responses (CIRs) in A2A links. Through analysis on the obtained CIRs, it is revealed that ground reflection gives an impact on the CIR when flying over the sea; on the other hand, it is not clearly observed when flying over urban areas due to tall buildings likely block the reflection.

PLCCM2: Physical layer, channel coding and modulation 2go to top

Room: Fairmount Park
1:00 BER Performance Improvement for OFDM DF Infrastructure Relay Links
Enis Kocan (University of Montenegro, Montenegro); Milica Pejanovic-Djurisic (University of Montenegro & Centre for Telecommunications, Montenegro)
OFDM based infrastructure relay station (R), implementing decode-and-forward (DF) relaying, has been included in IMT-Advanced standards, in dual-hop scenarios. Ergodic capacity of such a relay system may be significantly enhanced if ordered subcarrier mapping (SCM) is implemented at R, and, at the same time, bit error rate (BER) performance is improved in this way. However, the level of the achieved BER improvement is very small, and in the region of high signal-to-noise ratios (SNRs) on hops, there is no improvement at all. Thus, in this paper we propose a solution where in the OFDM DF relay system with ordered SCM, one or more subcarriers with the lowest SNRs from both hops are omitted. The analytically obtained BER results, for the assumed uncoded BPSK modulated system, in Rayleigh fading scenario on both hops, are completely verified through simulations. They show that significant BER performance improvement is attained for the whole range of SNR values on both hops. Moreover, we made comparisons of the proposed solution with other OFDM DF relay systems, and with the case of OFDM direct transmission, thus showing that the achieved level of BER performance improvement justifies additional signal processing introduced at R.
1:22 On the Use of Okumura-Hata Propagation Model on Railway Communications
Nuno Cota (Instituto Superior de Engenharia de Lisboa, Portugal); António Serrador (Instituto Superior Tecnico, Technical University of Lisbon, Portugal); Pedro Vieira (Instituto de Telecomunicações and ISEL, Portugal); Ana Beire (Refer Telecom – Serviços de Telecomunicações and ISEL, Portugal); António J. Rodrigues (IT / Instituto Superior Técnico, Portugal)
Although Okumura-Hata prediction model has been a widely used model to estimate radio network coverage, its application in railways environment requires validation and additional studies. This paper presents the main results on a study based on measurements campaigns, and identifies significant differences in parameters that characterize the radio propagation in railways environment, for the 900 MHz band. Both the propagation slope and standard deviation measured values are presented in this work. For validation, the developed model setup was used in the radio planning process, setting a live GSM-R pilot network, operating in Portugal.
1:45 Improvement of Peak and Average Power Reduction of Trellis Shaped OFDM Signals by Controllable Region Expansion
Masaki Matsuoka (Yokohama National University, Japan); Ryota Yoshizawa (Yokohama National University, Japan); Hideki Ochiai (Yokohama National University, Japan)
Orthogonal frequency-division multiplexing (OFDM) is known for its excellent bandwidth efficiency and robustness against multi-path fading channels. The major drawback of OFDM is its high peak-to-average power ratio (PAPR) property that substantially reduces the power conversion efficiency of power amplifiers (PA). Trellis shaping (TS) is known as one of the effective methods to reduce peak power as well as average power of OFDM signals and its reduction capability depends on the number of regions in the quadrature amplitude modulation (QAM) constellations that are selectable by the shaping bits. In this paper, we propose a method to considerably improve the peak and average power reduction capability of trellis shaped OFDM by expanding the controllable regions for a given QAM constellation. The effectiveness of the proposed approach is confirmed by simulations in terms of PAPR and average power reduction capabilities as well as its bit error rate performance.
2:07 A Hardware Based Ricean Fading Radio Channel Simulator
Richard S. Wolff (Montana State University, USA); Ahmed Badawy (Qatar University, Qatar)
The rise of the need of fading radio channel simulators is due to time and cost of field tests of wireless communications systems. There exist two approaches to design a hardware based fading simulators, namely the filter based and sum of sinusoids (SOS) methods. This paper introduces a hardware based Ricean fading simulator that is based on SOS and utilizes empirical formulas that were derived based on extensive measurements to estimate the Ricean distribution K factor. The simulator presented here can simulate the Rican fading radio channel under different parameters including antenna height, antenna beamwidth, season and distance between the transmitter and the receiver.

2:30 PM - 4:00 PM (America/New_York)

IP2: Invited papersgo to top

Room: Central Park
2:30 Preliminary Measurements for Wireless Relay Network using UAS
Fumie Ono (National Institute of Information and Communications Technology, Japan); Kenichi Takizawa (National Institute of Information and Communications Technology, Japan); Hiroyuki Tsuji (NICT, Japan); Ryu Miura (NICT, Japan)
This paper presents a preliminary measurement result for a wireless relay network using small unmanned aircraft system (UAS). We consider the scenario where the UA circles above around the networks automatically and bridges the signals between ground access points (GAPs) of the distant networks. Such wireless relay networks using UA can be considered particularly useful for emergencies e.g., when the communication networks are partially or completely interrupted after the disaster or power failure. In this paper, measurement results are presented to demonstrate the reliability of the wireless relay network using UAS. Consequently, it is shown that the rice factor and delay time depend on the flight scenario of UAS.
3:00 Disaster Satellite Communication Experiments using WINDS and Wireless Mesh Network
Takashi Takahashi (National Institute of Information and Communications Technology, Japan); Byongpyo Jeong (NICT, Japan); Mitsugu Ohkawa (National Institute of Information and Communications Technology, Japan); Akira Akaishi (National Institute of Information and Commucanitons Technology, Japan); Toshio Asai (National Institute of Information and Communications Technology, Japan); Norihiko Katayama (National Institute of Information and Communications Technology, Japan); Maki Akioka (National Institute of Information and Communications Technology, Japan); Naoko Yoshimura (National Institute of Information and Conmmucations Techology, Japan); Morio Toyoshima (National Institute of Information and Communications Technology, Japan); Ryu Miura (NICT, Japan); Naoto Kadowaki (National Institute of Information and Communications Technology, Japan)
An unprecedented Great East Japan Earthquake occurred on March 11, 2011, and serious damage occurred. The terrestrial communication networks were damaged and to take contact with the stricken area was very difficult. Satellite communication has the feature of disaster resistant, and satellite mobile phone became the precious communication means just as after the earthquake disaster. The National Institute of Information and Communications Technology (NICT) built a broadband satellite line between the disaster preventions agencies and their dispatched team which worked on disaster response activities in stricken area using Wideband InterNetworking engineering test and Demonstration Satellite (WINDS). NICT researches and develops the resilient network against a disaster using wireless network and satellite network. Three types of earth stations for satellite communications are developing, fully-automatic transportable earth station, large-scale in-vehicle earth station and small in-vehicle earth station. NICT carried out the disaster satellite communication experiments using those earth stations. One was connected two wireless mesh network using satellite link and another was transmitted HDTV image from a moving earth station.
3:30 A Wireless Network System in TV White Space
Hiroshi Harada (National Institute of Information & Communications Technology (NICT), Japan); Kentaro Ishizu (National Institute of Information and Communications Technology, Japan); Homare Murakami (National Institute of Information and Communications Technology, Japan)
A wireless communication system in TV broadcasting band (470MHz-710MHz) has been developed. In the system its operational channels are set to the radio equipment according to calculation results provided from the white space database (WSDB). By the system, efficient wireless communication environment to accommodate increasing mobile traffic is expected, which consequently loads off traffic of wireless networks where current throughput is not sufficiently achieved due to traffic congestion and radio interference. This paper describes specification of white space database, white space base station, and its operation scheme.

PLCCM3: Physical layer, channel coding and modulation 3go to top

Room: Fairmount Park
2:30 Isolation-based Uplink Power Control for TD-LTE in TV White Space
Yuting Guo (Beijing University of Posts and Telecommunications, P.R. China); Caili Guo (Beijing University of Posts and Telecommunications, P.R. China); Chunyan Feng (Beijing University of Posts and Telecommunications, P.R. China); Dongming Li (Beijing University of Posts and Telecommunications, P.R. China); Xiaoming Li (Beijing University of Posts and Telecommunications, P.R. China)
In order to utilize TV White Space (TVWS) by deploying the cognitive radio technology and eliminate interference to DTV system, some researches set extra isolation which may reduce spectrum efficiency. In this study, power control is used. However, the existing TD-LTE power control algorithms are not proper for the coexistence of TD-LTE and DTV systems because the interference is not considered. A novel power control algorithm, Isolation-based Power Control Algorithm (IPCA), is proposed. Different from conventional Open-Loop Power Control (OLPC), IPCA sets target SINR for each user based on its isolation from DTV receiver because isolation between these two systems plays an important role in interference. Then the optimization problem of the parameter in IPCA is solved by Lagrangian multiplier method. The simulation result shows that IPCA can not only reduce the interference from TD-LTE to DTV, but also improve spectrum efficiency.
2:52 Optimization for Multi-relay Selection with Rateless Code in Cooperative Communication System
Yuchao Jin (Beijing University of Posts and Telecommunications, P.R. China); Yonghua Li (Beijing University of Posts and Telecommunications, P.R. China); Jiaru Lin (Beijing University of Posts and Telecommunications, P.R. China); Yueming Lu (Beijing University of Posts and Telecommunications, P.R. China)
In this paper, the joint relay selection and rateless codes scheme is considered for the three-stage transmission scenario with one source, multi-relay and one destination, where all nodes employ rateless codes when transmitting system information. During the transmission process, the source keeps sending messages until it receives enough ACK feedbacks from relays or the destination. The relays that finish decoding more quickly can participate in the transmission the moment it succeeds and help the other relays and the destination to accumulate more packets. As we introduce the communication among the relays, an increase of throughput can be obtained owing to the reduction of transmission time. It's also shown by simulations that the proposed schemes can gain a better performance, not only for system throughput, but also for energy consumption, which achieves more flexible tradeoff between system throughput and energy consumption.
3:15 Analysis of RoF-Echo Effect on OFDM Signal Transmission with EPWM Format
Xiaoxue Yu (The University of Electro-Communications, Japan); Motoharu Matsuura (The University of Electro-Communications, Japan); Yasushi Yamao (The University of Electro-Communications, Japan)
Radio over Fiber (RoF) technology integrates wireless access into optical networks. It contributes much for spreading broadband wireless access services to in-building areas and outdoor dead-spots. However, OFDM signals which are widely employed in current broadband wireless access systems suffer from nonlinearity and echoes in RoF channels. The echoes are caused by multiple reflections of light and have long delay compared to the OFDM symbol duration. In this paper, a RoF-echo channel model is proposed and employed in the analysis of the echo effect on the RoF transmission. The validity of the model is confirmed by experimental results. The combined effects of nonlinear distortion and echoes in the RoF channel on normal OFDM and EPWM (Envelop Pulse-Width Modulation) formatted OFDM signals are analyzed and evaluated by their EVM (Error Vector Magnitude) performances.
3:37 Performance of Turbo Frequency Domain Equalizer Using Iterative Decision-Directed Channel Estimation for DFT-Precoded OFDMA
Chihiro Mori (Tokyo City University, Japan); Yoshikazu Tanaka (Tokyo City University, Japan); Teruo Kawamura (NTT DOCOMO, INC., Japan); Nobuhiko Miki (Kagawa University, Japan); Mamoru Sawahashi (Tokyo City University, Japan)
This paper proposes iterative decision-directed channel estimation (IDDCE) associated with turbo frequency domain equalizer (FDE) for discrete Fourier transform (DFT)-precoded Orthogonal Frequency Division Multiple Access (OFDMA). By using soft-symbol replicas based on extrinsic log-likelihood ratio (LLR) at the Max-Log-MAP decoder output as well as reference signal (RS), the accuracy of channel response is improved in iterative inner loop employing feed-forward (FF)-FDE at each iteration of outer loop for turbo FDE. Computer simulation results show that the improvement in the required average received signal-to-noise power ratio (SNR) satisfying the target average block error rate (BLER) is saturated with a number of iteration times of 2 for both inner and outer loops regardless of a modulation scheme. We also show that the IDDCE using FF-FDE based on Minimum Mean-Square Error (MMSE) criterion at each iteration of turbo FDE is effective in improving the average BLER of turbo FDE.

SS12-1: Virtual Networks and Cloud Computinggo to top

Room: Monticello Park
Chair: Hongyan Cui (Beijing University of Posts and Telecommunications, P.R. China)
2:30 Malicious Node Detection for the Future Network Security from Epistemic Uncertainties
Xu Huang (University of Canberra, Australia); Muhammad Raisuddin Ahmed (University of Canberra, Australia); Hongyan Cui (Beijing University of Posts and Telecommunications, P.R. China); Shutao Li (Huana University, Australia)
— The next generation of WSN will benefit when sensor data is added to blogs, virtual communities, and social network applications. Wireless sensor networks (WSNs) are popular now as distributed networks exposed to an open environment, collecting of self-organized nodes with limited computation and communication capabilities and energy covering deployed areas that interested by the controllers. WSNs have been as aware of environmental technologies such as sound, water contamination, temperature, pressure, motion and other pollutants. However, as wireless communication becomes all sectors of daily life, the security threats to WSNs become increasingly diversified, prevention based due to the open nature of the wireless medium. The node in a WSN is called compromised becomes another major problem of WSN security because it allows an adversary to enter inside the security perimeter of the network and launch attacks, which has raised a serious challenge for WSNs. This paper is focusing on investigating interating wireless sensor networks with cloud computing with the case that internal attacks of WSNs with multi-hop and single sinker for the future network, such as compromised nodes in a deployed WSN, where we first present our novel protecting algorithm to WSN to protect it with the evidences that our novel algorithm works efficiently and effectively. Our new algorithm takes advantages from uncertain decisions, which means there is no need to know the structure before we check the network. It is involved in the posteriori probability of binary events represented by the beta family of density functions and Dempester Shafer theory (DST). AS it has no need to have any knowledge about the structure of the network, it will be flexible to use in real life.
3:00 Higher Quality of Infrared Images for Future Network Security Systems
Xu Huang (University of Canberra, Australia); Sheikh Md. Rabiul Islam (University of Canberra, Australia); Ming Yu Liao (University of Canberra, Australia); Shutao Li (Huana University, Australia)
It is well known that infrared (IR) imaging has been used extensively for various applications, in particularly in those dark conditions. Therefore, it has been widely employed in various tracking systems, in particularly, with the Internet of Things (IoT), sensors integrated with cloud computing, which makes IR even more popular for future networks. But various images, including IR images almost cannot avoid contaminations from various noises sources even when they were born. High quality images are particularly needed in those applications, especially for the security and military environments. In order to obtain a good quality of IR image for the future network security, in our current paper, it proposes a novel denoising algorithm based on Cohen-Daubechies-Feauveau wavelets followed by the low-pass filters with the length 9 and 7 (CDF 9/7) wavelet transform. In our algorithm, we first applied the lifting structure to improve the drawbacks of a traditional wavelet transform. As the normal wavelet transform appears to be restricted and limited for a class of opportunities of multi-scale representation of multi-dimensional signals to estimate the noise level and then remove them from original images, which is less efficient and effective. In contrast, our proposed algorithm in this paper is much efficient in estimating and reducing noises from the images contaminated by multi noises, such as Gaussian noise, Poisson noise, and impulse (Salt& pepper) noise. Experimental results on several tests for infrared images by using our algorithm are presented, as an example, under the noise with standard deviation  = 0.2 and density = 20% cases, for peak signal to noise ratio (PSNR) increasing 14%; mean square error (MSE) our method decreasing 83%; and mean of structural similarity (MSSIM) increasing 67% under the same conditions. Obviously, the results strongly support the fact that our proposed algorithm is significantly superior to other related methods.
3:30 A Virtual Network Embedding Alogrithm Based on Virtual Topology Connection Feature
Hongyan Cui (Beijing University of Posts and Telecommunications, P.R. China); Wenjun Gao (Beijing University of Posts and Telecommunications, P.R. China); Liu Jiang (Beijing University of Posts and Telecommunications, P.R. China); Yunjie Liu (Beijing University of Posts and Telecommunications, P.R. China)
Virtual network mapping provides a promising way to solve the ossification of current Internet. Mapping multiple virtual topologies onto a shared substrate network is a challenging problem. In this paper, we provide a new virtual network embedding algorithm based on virtual topologies connection feature and introduce a node connection-degree to measure the priority of the alternative physical nodes. Using the node connection-degree based on the virtual topologies feature, we can select nodes which are closer to each other and the algorithm will be more effective. Multiple simulation results show that our new algorithm enhances the performance of the acceptance ratio, long-term revenue/cost (R/C) and the runtime compared with the existing embedding algorithms.

4:30 PM - 6:00 PM (America/New_York)

LOCMOB: Localization and Mobilitygo to top

Room: Central Park
Chair: Yishuang Geng (Worcester Polytechnic Institute, MA, USA)
4:30 Modeling the effect of human body on TOA ranging for indoor human tracking with wrist mounted sensor
Yishuang Geng (Worcester Polytechnic Institute, MA, USA); Jie He (University of Science and Technology Beijing, P.R. China); Haokun Deng (Worcester Polytechnic Institute, USA); Kaveh Pahlavan (WPI, USA)
In TOA based indoor human tracking system, target sensors are often mounted to the surface of human body which may raise non-line-of-sight (NLOS) issues and give raise to significant ranging error. However, analysis on the influence of human body on TOA ranging result has never been seen from previous researches. In this paper, we focus on geometrical information, effect of system bandwidth and signal to noise ratio and provide a detailed analysis on the effect of human body on TOA ranging. Perspective of creeping wave around the surface of human body has been taken into consideration and a statistical TOA ranging error model has been built based on measurements in office environment. The wrist model in this paper separates the ranging error caused by multipath phenomenon and ranging error caused by blockage of human body by partitioning the measurement scenario into line-of-sight (LOS) and NLOS scenario. Comparison has been made between wrist model and chest model in our previous work and the performance of this wrist model has been validated.
4:52 A Tracking-by-Detection Method with Radio-Frequency Tomography Network
Aidong Men (Beijing University of Posts and Telecommunications, P.R. China); Jianfei Xue (Beijing University of Posts and Telecommunications, P.R. China); Bo Yang (Beijing University of Posts and Telecommunications, P.R. China); Yang Li (Beijing University of Posts and Telecommunications, P.R. China); Hang Liu (Beijing University of Posts and Telecommunications, P.R. China)
This paper presents a tracking-by-detection method which can localize and track an unknown and time-varying number of moving objects with radio-frequency tomography network. First, a novel detection method based on scanning circles is proposed to preliminarily estimate the number of targets and determine the multi-target positions using the received signal strength measurements. Then, particle probability hypothesis density filter algorithm is applied to perform target tracking and eliminate false positives caused by multipath environment or system noise. Experimental results demonstrate that the tracking-by-detection method achieves high accuracy in estimating target number and positions.
5:15 A SON Enhanced Algorithm for Observed Time Differences Based Geolocation in Real 3G Networks
Pedro Vieira (Instituto de Telecomunicações and ISEL, Portugal); Nuno Varela (Instituto Superior de Engenharia de Lisboa, Portugal); Nuno Fernandes (CELFINET, Consultoria em Telecomunicacoes, Lda., Portugal); Nuno Guedes (CELFINET, Consultoria em Telecomunicacoes, Lda., Portugal); Luís Varela (CELFINET, Consultoria em Telecomunicacoes, Lda., Portugal); Nuno Ribeiro (CELFINET, Consultoria em Telecomunicacoes, Lda., Portugal)
This paper presents a SON enhanced approach for OTD Based Geolocation in a real 3G UMTS Network. The algorithm was implemented using cell, measurement report and drive-test data, the last just for geolocation accuracy determination. It uses a dual convergence approach evolving Node B time reference estimation followed by trilateration, boosting convergence. A motion model Kalman filtering module was developed, and tuned for urban mobile. Around 35% of the events were geopositioned, which motivates using OTD measurements for geolocation in live networks. The median accuracy achieved by the algorithm was 178 m, which is rather promising, considering that OTD measurements have an intrinsic uncertainty of a UMTS chip, i.e, 78 m.
5:37 On the Social Properties of Mobility Models: a Genetic Algorithm-based Approach
Bo Lv (Beijing University of Posts and Telecommunications, P.R. China); Muqing Wu (BUPT, P.R. China); Jingrong Wen (Beijing University of Posts and Telecommunications, P.R. China); Wang Dongyang (BUPT, P.R. China)
The performance of routing protocols in MANETs is significantly influenced by the mobility of wireless devices. Recently, many social based mobility models generate synthetic traces to capture the statistical properties detected from real traces, leaving the cause of these movement patterns untouched. As a highlighted novelty of this paper, we explore the driving force of complicated social behaviors from an evolutionary point of view and propose a genetic algorithm-based mobility model (GAMM). Using "less movement cost, more social gains" as the metric of trace's fitness to the environment, Levy Walk and inter-contact time with truncated power-law distribution emerge from generations of evolutions, accompanied by the reduction of location entropy. Two practical extension models and a simulation experiment are also presented to show the expandability and scalability of GAMM.

SS14: Cooperative Wireless Systemsgo to top

Room: Fairmount Park
Chair: António J. Rodrigues (IT / Instituto Superior Técnico, Portugal)
4:30 Simple Wireless Cooperative System to Enhance the Channel Capacity in Microcell Scenarios
Ivo Sousa (Instituto de Telecomunicações/IST, Technical University of Lisbon, Portugal); Maria Paula Queluz (Instituto Superior Técnico, Portugal); António J. Rodrigues (IT / Instituto Superior Técnico, Portugal)
In this paper we discuss the use of a simple wireless cooperative system based on Multiple-Input Multiple-Output (MIMO) spatial multiplexing, in order to enhance the channel capacity of single antenna and multiple antenna terminals in microcellular systems. The proposed cooperative system is envisioned for technology that is already available in the market, it can be implemented in a transparent manner to the cellular network and it can be used both in the downlink and in the uplink. We also propose a simple, fast and distributed scheme to select a good relay within the cooperative system. The study is performed using a simulator that generates realistic frequency-selective channel realizations for a microcell environment. The simulation results show that the proposed cooperative system plus the relay selection scheme accomplish the goal of enhancing the channel capacity for all the considered situations.
4:48 MMSE Interference Alignment Algorithms with Low Bit Rate Feedback
Sara Teodoro (University of Aveiro & Institute of Telecommunications, Portugal); Adão Silva (Instituto de Telecomunicações (IT)/University of Aveiro, Portugal); Rui Dinis (Instituto de Telecomunicacoes & FCT-UNL, Portugal); Atilio Gameiro (Telecommunications Institute/Aveiro University, Portugal)
Interference alignment (IA) is a promising technique that allows high capacity gains in interfering channels. However to achieve the maximum degrees of freedom it requires the knowledge of the different link channel state information (CSI) between base station (BS) and user terminal (UT). A quantized version of the CSI is feedback from the UT to the BS, which is then used to perform the overall IA design. In this paper we propose several low-complexity and low-bit rate channel quantization techniques, requiring the quantization of only the non-zero components of the channel impulse response. The proposed techniques are evaluated under the minimum mean squared error (MMSE)-based IA algorithms for the downlink of OFDM signals. We show that to achieve performances close to the ones obtained with perfect channel knowledge, only a small number of bits is needed for channels quantization comparatively to the previous proposed techniques.
5:06 Cooperative Diversity with Cooperative Selection-and-Stay Combining with Multiple Decode-and-Forward Relays
Yawgeng A. Chau (Yuan-Ze University, Taiwan); Mostafa Kamil Abdulhusain Al-Harbawi (Yuan-Ze University, Taiwan)
Cooperative selection-and-stay combining (CSSC) is analyzed for energy-efficient cooperative diversity with multiple decode-and-forward relays, where the relays are not activated all the time. To illustrate reception performance, BPSK signaling over independent and identically distributed (i.i.d.) Rayleigh fading channels is considered. The bit error rate (BER) of the end-to-end reception and average relay utilization are derived, and a closed-form approximation of the BER is obtained. Numerical results of BER performance are presented and compared for different cases.
5:24 The Impact of Channel Estimation Errors in Wireless Sensor Networks over Cooperative Modulation Diversity
Marcelo Portela Sousa (Federal University of Campina Grande, Brazil); Waslon Terllizzie Araujo Lopes (UFCG - Federal University of Campina Grande & IECOM - Institute for Advanced Studies in Communications, Brazil); Francisco Madeiro (Universidade Catolica de Pernambuco, Brazil); Marcelo S. Alencar (Federal University of Campina Grande & Institute for Advanced Studies in Communications, Brazil)
Channel estimation errors can impact the performance of a cooperative wireless sensor network. In this paper the authors evaluate that impact, related to the packet loss rate and network lifetime. The LMS algorithm and a first order PLL are used to estimate the modulus and phase information, respectively. The network assumes a heterogeneous architecture, with the cooperation of cluster-heads and vice cluster-heads, if transmission errors occur. The cooperative scheme is formed by the rotation of a QPSK constellation and the independently interleaving of the in-phase and quadrature symbol components. The simulation results show that, even in the presence of channel estimation errors, the cooperative scheme overcomes the performance of the simple QPSK, regarding the packet loss rate. However, the network lifetime is longer for the QPSK scheme and for the cooperative modulation diversity with perfect channel estimation.
5:42 Spectrum Sharing LTE-Advanced Small Cell Systems
Ahmed Alsohaily (University of Toronto, Canada); Elvino Silveira Sousa (University of Toronto, Canada)
Cellular systems are designed such that a certain amount of radio spectrum is allocated for their exclusive use; to ensure that interference is tightly controlled within these systems. For competitive reasons, spectrum is divided between operators despite the resulting inefficiency in the overall spectrum utilization; as larger systems are more efficient than groups of smaller systems. For systems with relatively large cells and significant number of users per cell the loss in efficiency is modest. However, losses can become very large as cells become smaller and the need for new spectrum sharing means between operators becomes imminent. This paper presents a cooperative spectrum access framework for multiple operators to share spectrum. Primary spectrum license owning operators broadcast their spectrum occupancy information to allow small cells of other operators to access their spectrum as secondary users; and thus enabling greater spectrum utilization in small cells. LTE- Advanced systems employing small cells are considered. Simulations show that the proposed spectrum access framework enables small cells to achieve substantial performance gains without affecting the primary spectrum owning system even when the small cell deployment density varies significantly between operators.

SS12-2: Virtual Networks and Cloud Computinggo to top

Room: Monticello Park
Chair: Hongyan Cui (Beijing University of Posts and Telecommunications, P.R. China)
4:30 Methods with Low Complexity for Evaluating Cloud Service Reliability
Hongyan Cui (Beijing University of Posts and Telecommunications, P.R. China); Yang Li (Beijing University of Posts and Telecommunications, P.R. China); Jian-ya Chen (Beijing University of Posts and Telecommunications, P.R. China); Yunjie Liu (Beijing University of Posts and Telecommunications, P.R. China)
The critical significance of cloud computing lies in its ability to deliver high performance and reliable calculation on demand to external customers over the Internet. Because of heterogeneous software/hardware components and complicated interactions among them, the probability of failures improves. The services reliability arouses more attention. Cloud reliability analysis and modeling are very critical but hard because of the complexity and large scale of the system. The connectivity of subtasks and data-resources can affect the system reliability. This paper proposes the analysis methods of cloud service reliability based on a simple manner on two conditions: independent failures and correlated failures, which uses Graph Theory, Bayesian networks and Markov models. Simulation results show that time complexity of our proposed method has been greatly improved than traditional algorithms. Our new methods ensure the precision of reliability calculation.
5:00 Adapting Cloud Computing Service Models to Subscriber Requirements
O Arinze (Drexel University, USA); Murugan Anandarajan (Drexel Universty, USA)
Cloud computing is a form of computing that enables using organizations to deploy and access applications over the Internet on demand in a dynamically scalable and virtualized form. This paper discusses organizational requirements for cloud computing and different forms of cloud computing. It examines ways in which cloud computing service models can be matched to a subscriber's information processing requirements and lays the foundation for a testable model.
5:30 An Efficient Virtual Network Embedding Algorithm with Delay Constraints
Shengquan Liao (College of Computer Scince and Technology, Zhejiang University, P.R. China); Chunming Wu (College of Computer Science, Zhejiang University, P.R. China); Min Zhang (Hangzhou Dianzi University, P.R. China); Ming Jiang (Hangzhou Dianzi University, P.R. China)
Virtual network technique provides an effective way to crack with the "ossification" problem of current network. How to construct a QoS guaranteed virtual network to better sever the customers becomes an essential concern of Internet Service Providers (ISPs). In this paper, we propose an algorithm (K-VNE-DC) based on multi-agent approach to embed virtual networks onto substrate network with delay constraints. Previous works implement virtual network embedding on the basis of substrate resources (nodes capacity and links bandwidth) with various strategies. However, these strategies would introduce an unnecessary waste of substrate resources. We aim to map virtual links onto substrate paths with minimum bandwidth cost whilst keeping the delay constraints. Simulation results show that K-VNE-DC can achieve an excellent performance in average bandwidth cost, and guarantee the accept ratio and QoS well-pleasing at the same time.