Tutorials offered at VTC 2008 Spring

Sunday 11 May 2008 

T1: Iterative Receiver Design - The Tutorial
Presenter: Henk Wymeersch, Massachusetts Institute of Technology
Time: 9.00-12.30
Room: TBD

Abstract
Factor graphs provide a general and elegant framework for developing inference algorithms, with important applications in the design of iterative receivers. The main goal of this tutorial is to provide a rigorous, yet intuitive introduction of factor graphs and their use in developing iterative algorithms for statistical inference. We emphasize the use of the factor graphs for the design of iterative receivers, with applications in decoding (turbo and LDPC codes), MIMO detection and multi-user detection.

Tutorial Objectives
Attendees of this tutorial will be able to cast a wide variety of inference problems in a factor graph, and solve those inference problems using message passing. This will allow them to develop algorithms in a systematic and rigorous fashion. Secondly, attendees will gain insight in how some of the most important algorithms in digital receivers can be seen as instances of factor graphs. Thirdly, the factor graph approach lends itself well to algorithm development in a wide variety of fields, and it is my hope that attendees will transpose the knowledge from this tutorial to their own fields.

Tutorial Outline

Digital Data Transmission: We discuss how binary information is conveyed from transmitter to receiver, and how effects such as multi-path, fading and noise impact the received signal. We described the main functionalities required of the receiver.

Optimal Detection and Estimation: We introduce the notion of optimal detection in an abstract setting. We develop optimal detection/estimation strategies, including maximum a posteriori (MAP) and minimum mean square error (MMSE) estimation. We show that the key problem boils down to a computation of marginals. Time permitting, we will discuss Monte Carlo techniques, and their relation to optimal detection.

Factor Graphs and the Sum-Product Algorithm: We describe factor graphs, and, using simple examples, show how they can be used to compute marginals of a function.

Statistical Inference with Factor Graphs: We link factor graphs with optimal detection, and describe several statistical inference problems that can be solved using factor graphs. We go into details of message representation, and iterative (turbo) processing. Time permitting, we apply our knowledge to hidden Markov models.

Iterative Receiver Design: Tying everything together, we apply factor graphs to our original problem of developing an optimal iterative receiver. Key functionalities such as equalization, demapping and decoding are presented in a unified framework. Turbo and LDPC codes, MIMO detection and multi-user detection will be covered.

Advanced topics: Recently, there has been a lot of interest in distributed inference for wireless networks. We show how factor graphs can be employed in developing algorithms for distributed inference. We consider the important topic of localization and tracking in ad-hoc networks, and present a solution based on factor graphs. Time permitting, we will discuss the link between factor graphs and statistical physics.

Primary Audience
The primary audience consists of graduate students and research engineers working in the fields of wireless communications and networking. The secondary audience consists mainly on students and researchers in related fields.

Novelty
Despite the enormous scope of this tutorial, the prerequisite knowledge is very limited. This makes this tutorial unique and attractive to people with different backgrounds.
We present a unifying and elegant theory for a wide variety of old and new algorithms. These range from the Viterbi and BCJR algorithms to iterative detection of multi-user systems and distributed inference for ad-hoc networks. This tutorial will enable attendees to think about algorithms in a different, more rigorous and systematic way.

Biography
Henk Wymeersch is a postdoctoral associate with the Laboratory for Information and Decision Systems (LIDS) at the Massachusetts Institute of Technology (MIT). He obtained the Ph.D. degree in electrical engineering in 2005 from Ghent University, Belgium. In 2005-2006, Henk Wymeersch was a postdoctoral fellow of the Belgian American Educational Foundation at MIT, and in 2006 he won the Alcatel Bell Scientific Award for his Ph.D. thesis. He was a guest lecturer at MIT in 2005 and 2006 for the course "Statistics for Scientists and Engineers", dealing with a wide variety of algorithms for inference and estimation. He has given invited talks/tutorials on factor graphs at MIT, Georgia Tech, Ghent University, the Alcatel-Lucent Technical Academy, and several international conferences. He is a member of the IEEE, associate editor for the Journal of Computer Systems, Networks, and Communications, and author of the book from Iterative Receiver Design (Cambridge University Press, August 2007). His research interests include algorithm design for wireless transmission, statistical inference and iterative processing.

T2: Security and Survivability and Their Interactions for Wireless Networks
Presenter: Yi Qian, National Institute of Standards and Technology
Time: 9.00-12.30
Room: TBD

Abstract
Information assurance (IA) techniques employed in wired networks have limited direct applicability in wireless networks because of the unique aspects of wireless networks (e.g., user mobility, wireless communication channel, power conservation, limited computational power in mobile nodes, security at the link layer, etc.). The interaction between the components of information assurance, namely availability and security in a wireless network environment poses new challenges. In this tutorial, we explore the issues related to the integration of and interaction between approaches, models, architectures, etc., prevalent in the security and survivability areas of wireless networks. In particular, we view IA as a growing area that can form an umbrella to bring together the efforts in security and survivability areas, mainly because their primary goal is to provide an adequate level of assurance that the wireless networks and infrastructures can be relied upon and trusted. Furthermore, the interaction between the survivability and security of wireless networks is only beginning to be addressed in the research literature but is a crucial topic for successfully building IA into wireless networks. The goal of this tutorial is to present a sample survey of survivability and security techniques followed by an in-depth look at how one can model these two components interacting in providing IA and what the challenges are for the assurance of emerging wireless networks.

Tutorial Objectives
The objective of this tutorial is to present a sample survey of survivability and security techniques for wireless networks, followed by an in-depth look at how one can model these two components interacting in providing IA and what the challenges are for the assurance of emerging wireless networks. The audience will learn the current wireless network system security and survivability approaches, like confidentiality, integrity, availability, accountability, reliability, faulty prevention, avoidance and tolerance, and performability, followed by the issues related to the integration of and interaction between approaches, models, architectures, etc., prevalent in the security and survivability areas of wireless networks.

Tutorial Outline

Introduction

Information Assurance for Wireless Networks
Current Security Approaches in Wireless Networks
- Confidentiality
- Integrity
- Availability
- Accountability
Current Survivability Approaches in Wireless Networks
- Reliability
- Availability
- Faulty Prevention, Avoidance and Tolerance
- Performability

Integrating Survivability and Security for Wireless Networks
Modeling Techniques for Secure and Survivable Systems
- Analytical Modeling Techniques
- Security Modeling
- Survivability Modeling
Integrated Fault and Security Management
- Active Integrated Fault Identification Framework
- Fault and Security Management on High-Speed Networks
Wireless Systems Security and Survivability Interactions
- Framework for Wireless Network Survivability and Security
- Interaction between Survivability and Security in Wireless Networks

Conclusion

Primary Audience
Researchers, engineers, graduate students and professors, anyone who is interested in design, operating, and management of wireless networks and systems

Novelty
Information assurance techniques employed in wired networks have limited direct applicability in wireless networks because of the unique aspects of wireless networks (e.g., user mobility, wireless communication channel, power conservation, limited computational power in mobile nodes, security at the link layer, etc.). The interaction between the components of information assurance, namely availability and security in a wireless network environment poses new challenges. This tutorial is the first of the kind to address the interactions of survivability and security for wireless networks, which we believe is a very important step in design and operating a successful wireless networks.

Biography
Yi Qian is with National Institute of Standards and Technology. He was an Assistant Professor in the Department of Electrical and Computer Engineering, University of Puerto Rico at Mayaguez (UPRM) between July 2003 and July 2007. At UPRM, Dr. Qian regularly taught courses on wireless networks, network design, network management, and network performance analysis. Prior to joining UPRM in July 2003, he worked for several start-up companies and consulting firms, in the areas of voice over IP, fiber optical switching, internet packet video, network optimizations, and network planning, as a Technical Advisor and a Senior Consultant. He had also worked several years for the Wireless Systems Engineering Department, Nortel Networks in Richardson, Texas, as a Senior Member of Scientific Staff and a Technical Advisor. While in Nortel, he was a project leader for various wireless and satellite network product design projects, customer consulting projects, and advanced technology research projects. He was also in charge of wireless standards development and evaluations.

He received a Ph.D. degree in Electrical Engineering with a concentration in Telecommunication Networks from Clemson University. His current research interests include network security, network management, network modeling, simulations and performance analysis for next generation wireless networks, wireless sensor networks, broadband satellite networks, optical networks, high-speed networks and internet. He has publications and patents in all these areas. He is the co-editor and a contributor to the book “Information Assurance: Dependability and Security in Networked Systems” published by Morgan Kaufmann in 2007.

He has been on numerous conference technical committees including serving as the General Chair of the International Symposium on Wireless Pervasive Computing 2007, the Technical Program Co-Chair of the IEEE GLOBECOM 2006 – Symposium on Wireless Communications and Networking, and the Technical Program Co-Chair of the Workshop on Information Assurance 2006 and 2007. He is currently serving on the editorial board for Wiley Wireless Communications and Mobile Computing Journal, and he is an Associate Editor for Journal of Security and Communication Networks, and an Associate Editor for Journal of Computer Systems, Networks, and Communications. He is also the guest editor for IEEE Communications Magazine, special issue on Advances in Mobile Multimedia Networking and QoS. Dr. Yi Qian is a member of Sigma Xi, IEICE, and ACM, and a senior member of IEEE.

T3: Evolution and Future Development of Cognitive Radio Technology
Presenter: Xianbin Wang, University of Western Ontario
Time: 9.00-12.30
Room: TBD

Abstract
New spectrum allocation technologies and cognitive radio have been gaining considerable momentum recently, mainly due to the dilemma of the spectrum overcrowding and its extremely low utilization rate. According to FCC, temporal and geographical utilization rate of the assigned spectrum can be as low as 15% at any given time and location. Although the fixed spectrum assignment policy generally served well in the past, the dramatic increase in wireless communications in recent years poses a looming challenge due to spectrum overcrowding.

The limited availability of spectrum and the inefficiency of its usage necessitate new research and development on cognitive radio technology. This tutorial directly addresses the enabling technologies and platforms supporting the cognitive radio communications as well as the fundamental impact on future spectrum regulation and policies. We will commence with a comprehensive overview of the enabling technologies for such system in the context of dynamic spectrum management and coexistence of the heterogeneous wireless devices. The focus of this tutorial is the relevant enabling technologies and platforms for cognitive radio, particularly adaptive transmission techniques. The unique requirement to achieve spectrum opportunistic communication is thoroughly analyzed. New dynamic spectrum allocation technologies will be discussed. The system design and implementation requirements of the transceiver platforms with the capability of spectrum awareness will also be presented in details.

Tutorial Objectives
Today's wireless communication systems are characterized by a fixed spectrum allocation policy, i.e. the spectrum is regulated by governmental agencies and is assigned to license holders on a long term basis for specific geographical regions. However, conventional spectrum allocation limited to specific usage does not take into account the temporal and geographical nature of the spectrum usages and prevents reuse of these frequencies. According to FCC, temporal and geographical utilization rate of the assigned spectrum can be as low as 15%. Although the fixed spectrum assignment policy generally served well in the past, the dramatic increase in wireless communications in recent years poses a looming challenge due to spectrum overcrowding. As a result, improving the spectrum utilization efficiency is essential to support the wireless communications that will continue to fuel the economic growth. The limited availability of spectrum and the inefficiency of its usage necessitate new research and development on cognitive radio for dynamic spectrum allocation and coexistence of the heterogeneous wireless systems. This tutorial directly addresses the enabling technologies and platforms supporting the cognitive radio as well as the fundamental impact on future spectrum regulation and policies. Emerging dynamic spectrum allocation technologies, including the self-organizing through competition and coordination, location-aware spectrum allocation, and spectrum-pooling techniques, will be presented. Coexistence of various wireless communication devices with more spectral flexibilities will be covered. The proposed tutorial is also closely related to current commercial and industry standard development. Wireless LAN IEEE 802.11 devices already operate with a listen-before-talk spectrum access and with dynamically changing frequencies and transmission power. With the transition of analog to digital television broadcasting, the total number of the digital TV channels would be significantly reduced to maintain the current terrestrial TV coverage. FCC is currently seeking the reuse of the spectral white spaces for different applications. It is therefore envisioned to allow unlicensed reuse of the some of the TV broadcast band for cognitive radios upon identification of spectrum opportunities. This change is pursued in parallel in many regulatory domains worldwide. The IEEE 802. 22 study group is currently working on a new standard for efficient use of the DTV band for broadband access. Under these circumstances, a comprehensive understanding of such spectrum conditions and spectrum sharing mechanism for cognitive radio is essential for the successful deployment of such spectral efficient systems. It is expected that the audience of the tutorial will gain a comprehensive overview of the recent development of spectrum allocation technologies, the related enabling technologies and platforms, as well as the impact to the relevant industry. Significant benefits will be brought to the researchers, engineers, and government officials in this emerging area of dynamic spectrum allocation.

Tutorial Outline

1.Overview of existing spectrum management technologies
Principles of current spectrum management techniques
Spectrum regulations and policies
Performance evaluation of the exiting techniques and the need for new spectrum regulation
2.Unique requirement for cognitive radio
Temporal, spectral and spatial sensing techniques
Flexible and robust transmission techniques
Fare spectrum sharing mechanism
3. New dynamic spectrum allocation techniques
Unlicensed usage
Spectrum spooling
Location based spectrum allocation techniques
4. Transceiver architecture supporting dynamic spectrum allocation
Hardware and software requirements
Cognitive radio
Software defined radio
5. Physical layer design for cognitive radio communications
Reliable sensing techniques
Adaptive transmission technologies
Autonomous transmission parameter detection
6. Spectral coexistence of heterogeneous wireless networks
Spectrum footprint minimization
Spectrum usage reporting
Interference control between the unlicensed user and primary user
Multi-objective optimization for spectral coexistence
7. Future development and impact of new spectrum regulations
Performance limits of cognitive radio
Spectrum policy challenges for cognitive radio
Impact to wireless communications industry
Security concerns

Primary Audience
This tutorial is designed to appeal to a wide range of audience, requiring a modest background in wireless communications and signal processing. Research and development engineers, telecommunications managers, academic researchers and government spectrum management officials may find the wide coverage of the tutorial extremely attractive.

Novelty
The tutorial presents a comprehensive overview of the enabling technologies for cognitive radio in the context of spectrum management regulations. The unique requirement to achieve cognitive radio communication is thoroughly analyzed. The system design and implementation requirements of the transceiver platforms with the capability of spectrum awareness will also be presented in details.

Biography
Xianbin Wang received his Ph.D. from National University of Singapore in 2001. He was with Institute for Infocomm Research, Singapore (formerly known as Centre for Wireless Communications) as a Senior R & D engineer in 2000. From Dec. 2000 to July 2002, he was a system designer at STMicroelectronics, Inc., where he was responsible for system design for DSL and Gigabit Ethernet chipsets. From July 2002 to Dec. 2007, he was with Communications Research Centre Canada as a Research Scientist. Dr. Wang was nominated as a Canada Research Chair in Wireless Communication and joined the University of Western Ontario in Jan. 2008. He is currently working on advanced transmission technologies and spectrum management related studies. Dr. Wang is also an Adjunct Professor at Laval University, Canada. He has over 90 publications on various communication system design issues, including around 60 IEEE Journal and Conference papers, 10 granted and pending patents, and several standard contributions.

Dr. Wang is a Senior Member of IEEE. He is the recipient of the IEEE Scott Helt Memorial Award for the Best Paper published in IEEE Transactions on Broadcasting in 2004. He currently serves as an Associate Editor for IEEE Transactions on Wireless Communications, IEEE Transactions on Vehicular Technology and IEEE Transactions on Broadcasting.

Dr. Wang was involved in a number of IEEE conferences including GLOBECOM, WCNC, VTC, and ICME, on different roles such as TPC, session chairs, and tutorial instructor.



 

 

T4: Advances in Multiuser MIMO Systems
Presenter: Li-Chun Wang, National Chiao Tung Uni. Taiwan; (2) Tomoaki Ohtsuki, Keio Unig. Japan
Time: 13.30-17.00
Room: TBD

 

Abstract
Multiple-input multiple-output (MIMO) antenna techniques have been the subject of great interest over the past decade and have been adopted in the emerging wireless systems. Recently, personalized broadcast becomes an interesting and important application for MIMO technologies, which aims to serve multiple users concurrently with personalized data for each individual user. Interestingly, the potential gains of MIMO antenna techniques in this point-to-multipoint environment can be even larger than for the point-to-point system. The goal of this tutorial is to provide attendees with an understanding of benefit and tradeoff of implementing MIMO personalized broadcast systems. The key enabling techniques for MIMO personalized broadcast systems, including dirty paper coding, scheduling, transmit beamforming, receive beamforming, and feedback mechanisms will be investigated from the system and network perspective in this tutoria

Tutorial Objectives
The participants are expected to learn the benefit and tradeoff of different enabling techniques to implemen MIMO personalized broadcast systems, including dirty paper coding, scheduling, transmit beamforming, receive beamforming, feedback mechanisms, fairness, and power allocation issues. We also will highlight the future promising multiuser MIMO systems, such as multi-user MIMO-OFDM and peer-to-peer MIMO ad hoc networks.

Tutorial Outline


1. Background on MIMO antenna techniques (0.25 hr)
- MIMO Antenna Techniques
- Multiuser Diversity
- Scheduling Techniques
2. Point-to-Multipoint MIMO receive beamforming and scheduling (1 hr)
- Diversity-based scheduling
- Multiplexing-based scheduling
- Cross-layer consideration
3. Spatial Multiplexing in point-to-multipoint systems by transmit beamforming (0.5hr)
- Opportunistic beamforming and Dirty Paper Coding
- Random beamforming
- Zero-Forcing beamforming
4. MIMO in 3GPP LTE (0.5 hr)

5. Feedback mechanism, fairness, and power allocation issues (0.5 hr)

6. Conclusion (0.25 hr)

Primary Audience
From our experience giving this tutorial in three conference, we find that both academic and industry are all interested in the multiuser MIMO techniques.

Novelty
Multiuser MIMO broadcast systems aims to serve multiple users concurrently with personalized data for each individual user. However, to exploit the potential gains of MIMO antenna techniques in this point-to-multipoint environment, many proposed enabling techniques are needed to be investigated from a system and network aspect. One interesting concept of soft coverage introduced in the MIMO scheduling system can improve the coverage performance without increasing transmit power. Besides, the detailed discussion of cyclic delay diversity techniques suggested in 3GPP LTE are quite new and useful to the audience.

Biography
Dr. Li-Chun Wang received the B.S. degree from National Chiao Tung University , Taiwan, R. O. C. in 1986, the M.S. degree from National Taiwan University in 1988, and the Ms. Sci. and Ph. D. degrees from the Georgia Institute of Technology , Atlanta, in 1995, and 1996, respectively, all in electrical engineering. From 1990 to 1992, he was with the Telecommunications Laboratories of the Ministry of Transportations and Communications in Taiwan (currently the Telecom Labs of Chunghwa Telecom Co.). In 1995, he was affiliated with Bell Northern Research of Northern Telecom, Inc., Richardson, TX. From 1996 to 2000, he was with AT&T Laboratories, where he was a Senior Technical Staff Member in the Wireless Communications Research Department. Since August 2000, he has joined the Department of Communication Engineering of National Chiao Tung University in Taiwan as an Associate Professor and has been promoted to a full professor since August 2005. His current research interests are in the areas of cellular architectures, radio network resource management, cross-layer optimization, and cooperation wireless communications networks. Dr. Wang was a co-recipient (with Gordon L. Stuer and Chin-Tau Lea) of the 1997 IEEE Jack Neubauer Best Paper Award from the IEEE Vehicular Technology Society. He is an associate editor for the IEEE Transactions on Wireless Communications and holding three US patents.

Dr. Tomoaki Ohtsuki received the B.E., M.E., and Ph. D. degrees in Electrical Engineering from Keio University, Yokohama, Japan in 1990, 1992, and 1994, respectively. From 1994 to 1995 he was a Post Doctoral Fellow and a Visiting Researcher in Electrical Engineering at Keio University. From 1993 to 1995 he was a Special Researcher of Fellowships of the Japan Society for the Promotion of Science for Japanese Junior Scientists. From 1995 to 2005 he was with Tokyo University of Science. From 1998 to 1999 he was with the department of electrical engineering and computer sciences, University of California, Berkeley. He is now an Associate Professor at Keio University. He is engaged in research on wireless communications, optical communications, signal processing, and information theory. Dr. Ohtsuki is a recipient of the 1997 Inoue Research Award for Young Scientist, the 1997 Hiroshi Ando Memorial Young Engineering Award, Ericsson Young Scientist Award 2000, 2002 Funai Information and Science Award for Young Scientist, and IEEE the 1st Asia-Pacific Young Researcher Award 2001.

T5: Principles and Practice of Wireless Mesh Networks for the Future Internet
Presenter: Andreas Kassler, Dirk Staehle, Yevgeni Koucheryavy
Time: 13.30-17.00
Room: TBD

Abstract
Wireless Mesh Networks (WMN) are wireless multi-hop networks characterized by an infrastructure-based backbone and adaptive routing and radio resource management mechanisms that offer an economic alternative for providing broadband wireless internet connectivity. Realizing such vision requires a paradigm shift from current internet architecture towards a totally decentralized, self-managed, scalable and adaptive wireless access network. The advantage of WMNs is the possibility of rapid and cheap provision of Internet access networks avoiding the expensive and time-consuming process of laying cables. The application potential of WMNs is enormous including scenarios like emergency communications, home networks, community and neighborhood networking and services, or enterprise networks. The key challenges in WMN research are the development of MAC and routing protocols enabling a decentralized adaptive radio resource management. Cross-layer design in particular involving physical layer, MAC layer, and routing protocols is essential for an efficient operation. Delivering carrier-grade quality requires a proper planning and dimensioning of WMNs, resilient routing helps to increase the survivability of the network in case of failures. The tutorial will give a state of the art report on WMN research. Current trends in standardization are illustrated and an overview of ongoing projects and testbed deployments is given. A general classification of WMNs will be introduced and put into relation with IEEE802.16 Mesh mode and 802.11s. We will identify key research challenges and solution proposals for hot topics such as multi-channel and multi-radio mesh networks, cross-layer issues, and adaptive resource control.

Tutorial Objectives
This tutorial provides a comprehensive overview on principles behind WMNs, practical solutions as developed by relevant industry, and standardization issues. We first introduce the concepts of WMNs and give an overview on deployment scenarios and applications and services foreseen for such mesh networks. Different types of WMN technologies will be identified and classified according to their main functionality components like signaling, resource allocation, and routing. We will then systematically cover research issues and challenges associated with all layers in WMNs, especially in relation to the following topics: Capacity, Topology Control and Interference; Channel Selection and Management for Multi-Channel WMNs; Medium Access Control; Routing; Transport Layer; Interworking with other Networks; Congestion Control; Fairness and Cooperation; Quality of Service Provisioning; Cross-Layer Design; Security and Management; Peer-to-Peer services and multimedia delivery over mesh; which will have significant impact on the solution space. Furthermore, we will discuss planning and optimizing issues in WMNs. Here the challenge arises how to plan a self-organizing network. Special attention will be given to handle traffic dynamics in WMNs and adaptive cross-layer resource control. We then provide a detailed description of important architectural solution proposals from industry and academia that will capture the current state of the art in this area, including available testbeds. This will lead to a presentation and discussion of several open research challenges to foster the development of novel research ideas in the attendees. We finalize the tutorial by presenting current standardization efforts in relation to 802.11s WLAN meshes and 802.16 WiMAX mesh operation. The main differences between the solutions and their usefulness for different application scenarios will be discussed. After attending this tutorial, attendees will have a clear understanding of basic principles behind Wireless Mesh Networking and open research issues. Therefore, participants will be able to evaluate future developments and trends in this area. Attendees will also have an overview on ongoing standardization activities. The knowledge gained through this tutorial will help researchers and engineers to build better algorithms, protocols and services for WMNs. As several research issues involve several layers, it is important to gather different domain experts together. Therefore, VTC is seen as an excellent venue for this tutorial as it gathers together experts from different fields related to wireless mesh networks – from antenna, physical layer design, systems, wireless access, networks and up to service level. Discussion among such experts as part of this tutorial will help to catalyze novel ideas spanning several domain areas. The major goal of the tutorial is to provide the attendees with a general understanding of the functionality, the potential, and the challenges of WMNs without losing the connection to current mesh technologies.

Tutorial Outline

Introduction

Motivation and Use Cases

Overview of Wireless Mesh Networks

Terminology: A definition of Wireless Mesh Networks

Characteristics and underlying concepts

Classification of different approaches

Key Research Issues and Challenges
Capacity
Multi-Channel Multi-Radio WMN
Topology Control and Interference
Medium Access Control
Scheduling and quality of service
Resource allocation mechanisms
Routing
Transport Layer
Interworking with other Networks
Multi-homed mesh networks
Congestion Control, Fairness and Cooperation
Radio resource management
End-to-end Quality of Service Provisioning
Quality of experience based resource allocation
Cross-Layer Design
Security and Management
Peer-to-Peer services and multimedia delivery over mesh
Route selection and frequency planning in multi-radio, multi-channel and multi-technology networks
Mesh network planning: problem, tools and algorithms

Standardisation
802.11s
802.16

Research testbeds and Products
MIT Roofnet
Freifunk
Locustworld
Motorola Mesh Networking
Microsoft MCL
Heraklion Mesh

Future Directions

Primary Audience
This tutorial addresses a wide audience covering any PhD student and research engineer who is interested in the current and future challenges in the area of wireless mesh networks. The tutorial includes topics like state-of-the-art routing protocols or an overview of current mesh standards which provide a general introduction to mesh networks for non-experts, but also the challenges of hot topics like cross-layer issues in multi-channel and multi-radio mesh networks or adaptive resource allocation.

Novelty
Wireless mesh networks have drawn increasing attention in the recent years and are the main candidate for providing a wide coverage of broadband wireless Internet access in particular in regions with lacking network infrastructure. Although there have been related tutorials at prior VTC on relay, ad-hoc, and sensor network, the novelty of this tutorial is its focus on higher-layer aspects and cross-layering issues with lower layers.

Biography
Prof. Dr. Andreas J. Kassler (http://www.cs.kau.se/~andreask/) is currently Full Professor in Computer Science (Telematics and Multimedia Communications) at Karlstad University, Sweden. Dr. Kassler is a member of the editorial board of the Journal of Internet Engineering. He was been General Co-Chair for the International Workshop on Wireless Mesh Networks (WiMeshNets 2006), Co-Chair for the Minitrack “Quality of Service in Wireless Networks” at HICSS 38, 2005, and TPC member of several IEEE and other international conferences. His research interests include Wireless Mesh, Ad-hoc networks, multimedia networking, and Quality of Service Management.

Dr. Dirk Staehle (http://www3.informatik.uni-wuerzburg.de/staff/staehle/) is Assistant Professor at the Chair of Distributed Systems at the University of Würzburg, Germany. He has currently lead multiple industry co-operations in the field of GPRS, UMTS, and HSPA radio network planning with T-Mobile International, France Telecom R&D, and Vodafone Netherlands. His current research interests include analytic modeling of HSPA networks; UMTS radio network planning; radio resource management and planning of wirless mesh networks; source traffic modeling of wireless applications; integration of mobile communication systems with heterogeneous radio access technologies; capacity evaluation and deployment scenarios of WIMAX networks.

Yevgeni Koucheryavy (http://www.cs.tut.fi/~yk/) is an Associate Professor in the Institute of Communications Engineering at Tampere University of Technology, Finland. He actively participates in European IST projects and chairs ESF COST 290 Action “Traffic and QoS Management in Wireless Multimedia Networks”. His current research interests include QoS management techniques for wired/wireless communications, real-time services traffic optimization in wireless environment, and network performance evaluation.

T6: Cooperative Communications at MAC and Network Layers
Presenter: Chen-Khong Tham and Peng-Yong Kong, A*STAR Institute for Infocomm Research (I2R), Singapore
Time: 13.30-17.00
Room: TBD

Abstract
In wireless communications, cooperative techniques provide space-time diversity where neighboring nodes cooperate by transmitting from different locations at different times. This space-time diversity helps in achieving several benefits, such as better QoS, higher spectral efficiency and lower power consumption. Traditional space-time diversity techniques rely on precise instrumentation at the physical layer. In the first part of this tutorial, we present cooperative communication schemes at the MAC layer which can achieve space-time diversity without modification to the physical layer. Specifically, we will present several recent advances in cooperative MAC protocol designs. Several cooperative packet forwarding and cooperative retransmission algorithms schemes will also be presented.

Cooperative techniques also offer benefits at the network layer in wireless multi-hop and sensor networks. These benefits are in terms of improved end-to-end and system-wide performance such as assured QoS, reduced delay, cost or energy consumption. A closely-related concept to cooperation is coordination which addresses the issue of when each party in a distributed system should perform certain sub-tasks. Furthermore, cross-layer design, which can be viewed as cooperation between different layers of a protocol stack, is beneficial in certain settings. In the second part of this tutorial, we will present several theoretical frameworks for cooperation, coordination and cross-layer design such as game-theoretic, Markov Decision Process and distributed optimization approaches, and discuss several algorithms and protocols based on these frameworks. Lastly, we discuss the issue of user cooperation and sharing in community WiFi networks.

Tutorial Objectives
The objectives of this tutorial are to provide a comprehensive view of cooperative communication techniques at the MAC and network layers and to equip participants with the necessary background knowledge to incorporate cooperative schemes into their own MAC and network designs. Participants will get detailed coverage of cooperative MAC protocols, cooperative packet forwarding schemes and cooperative packet retransmission schemes. Several common theoretical frameworks suitable for cooperative systems such as game theory, Markov Decision Process (MDP) and distributed optimization will be covered. The strengths and weaknesses of each theoretical framework will be compared. Several algorithms and protocols for cooperative systems that are designed based on these frameworks will then be covered to provide participants with reference cases to enable them to start applying these techniques with greater confidence in their respective fields. Participants will also see concrete examples in which cooperative techniques have resulted in improved end-to-end and system-wide performance in terms of assured QoS, reduced delay, cost or energy consumption and better sensing performance in several types of networks, such as multi-hop and mesh networks, wireless sensor networks and multi-domain IP networks.

Tutorial Outline

Introduction

Cooperation at the MAC Layer
Cooperative MAC Protocols
Cooperative Packet Forwarding Schemes
Cooperative Packet Retransmission Schemes

Theoretical Frameworks for Cooperation, Coordination and Cross-Layer Design
Coordinated Multi-hop Scheduling
Game Theory
Markov Decision Process (MDP)
Distributed Optimization

Cooperative Algorithms and Protocols at Network Layer
Multi-Hop and Mesh Networks
Wireless Sensor Networks
Multi-Domain IP Network

User Cooperation and Sharing in Community/Municipal WiFi networks

Conclusion

Primary Audience
This tutorial is aimed at researchers, engineers and graduate students who deal with wired and wireless networked systems, as well as distributed computing systems such as wireless sensor networks and grid computing, and are interested to improve the performance and efficiency of these systems through better cooperation and coordination between the entities in the system.

Novelty
This tutorial is unique as it provides an up-to-date survey and in-depth coverage of recent advances in cooperative communications techniques at the MAC and network layers. Cooperative communications at the physical layer has been covered by other researchers at various IEEE conferences. Although the general feeling in the community is that cooperative techniques would also be useful at the MAC and network layers, there has not been a comprehensive and coherent coverage on this issue so far. We intend to address this gap in the proposed tutorial.

Biography
Chen-Khong Tham is an Associate Professor at the Department of Electrical and Computer Engineering (ECE) of the National University of Singapore (NUS), and Department Head of the Networking Protocols Dept at the A*STAR Institute for Infocomm Research (I2R), Singapore. He is the Programme Manager of a research programme on UWB-enabled Sentient Computing funded by the Agency for Science, Technology and Research (A*STAR) Singapore. His research interests are in coordinated quality of service (QoS) management in wired and wireless computer networks and distributed systems, such as wireless sensor networks. He obtained his Ph.D. and M.A. degrees in Electrical and Information Sciences Engineering from the University of Cambridge, United Kingdom, and held a 2004/05 Edward Clarence Dyason Universitas21 Fellowship at the University of Melbourne, Australia.

Peng-Yong Kong received the B.Eng. degree in electrical and electronic engineering (first-class honors) from the Universiti Sains Malaysia in 1995, and the Ph.D. degree in electrical and computer engineering from the National University of Singapore in 2002. He was an Engineer with Intel Malaysia from 1995 to 1998. After that, he was a Research Scholar with the Center for Wireless Communications, Singapore (currently the Institute for Infocomm Research), working towards the Ph.D. degree. Since 2001, he has joined the Institute for Infocomm Research, where he is currently a Senior Research Fellow. He is also an Adjunct Assistant Professor with the Electrical and Computer Engineering Department, National University of Singapore. His research interests are primarily in medium access control protocols, traffic scheduling, network traffic control and quality of service provisioning for wireless networks.

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