WCNC 2007 HALF DAY TUTORIALS
Sunday 11 March 2007
13:00 - 17:00
TU01 Title: Distributed Cooperative Communication Networks with application to cellular, ad hoc and sensor networks
In the tutorial, we will commence with a plethora of scenarios for which distributed and cooperative communication paradigms are beneficial. For example, cellular extensions yield drastic capacity and range improvements, thereby potentially saving large investment costs.
Also, systems, primarily designed to operate in ad hoc mode, benefit from a distributed and cooperative deployment in terms of increased data rates and/or power savings. A further example is the application to sensor networks, where a distributed approach yields significant power savings and also an increased link stability. The tutorial will deal with capacity, PHY and MAC layers, as well as cross-layer design. The tutorial is significantly enhanced with respect to tutorials given in 2006 and before.
Instructors: Mischa Dohler, France Telecom R&D, Hamid Aghvami, Centre for Telecommunications Research King's College London
TU02 Title: Turbo Receiver Design: From Theory to Practice
The turbo coding/decoding algorithm has made a huge impact on the performance of modern modem designs, ranging from deep space communications to 3G mobile communications. Likewise turbo receiver design based on the "Turbo Principle" is revolutionizing the way we design and develop modems for high capacity systems. Turbo receivers allow the minimization of interference, thereby allowing higher capacity systems which are more cost effective for both user and provider. This tutorial covers algorithms that utilise the so-called "Turbo Principle". This course provides a detailed study of digital signal processing concepts applied to communication systems. Specifically, it studies the baseband signal processing technique for iterative receiver design, in the context of the turbo principle, better known as turbo receivers. Topics covered include detection criteria, decoding methods, transmitter configurations, wireless channel modelling, receiver design and analysis techniques. By attending this course the participant will attain a fundamental understanding of how to design and analyse efficient receivers, how to use the turbo principle to mitigate interference and what the key design steps are. There will be practical system examples to reinforce the underlying principle and the application of this technique. By gaining an insight into these methods the participant will be able to apply the technique to a multitude of new real-world problems and system configurations, including systems that use antenna arrays, direct-sequence code-division multiple-access (DS/CDMA), continuous phase modulation (CPM), intersymbol interference (ISI) channels and much more.
Instructor: Mark Reed, Wireless Signal Processing Program National ICT Australia, the Australian National University
TU03 Title: Cognitive Wireless Communication Networks: An Introduction
"Cognitive radio" is an emerging technique to improve the utilization of radio frequency spectrum in wireless networks. An overview of the cognitive wireless communication networks (or dynamic spectrum access networks) is provided. Specifically, the basic concepts behind "cognitive radio" technology, main functions of cognitive radio, architectures and applications of cognitive wireless networks, and the major research challenges are described. A comprehensive survey on spectrum management, spectrum sharing, and spectrum mobility issues is provided. In this context, applications of microeconomic and game-theoretic models to solve the spectrum sharing problem are described (with some illustrative examples). To this end, the impacts of dynamic spectrum sharing on protocol design and engineering of cognitive wireless networks are discussed.
Instructor: Ekram Hossain, Department of Electrical and Computer Engineering University of Manitoba, Canada
TU05 Title: Research Challenges in IP Mobility Management
This tutorial will cover various research challenges faced in the design of mobility management protocols and techniques, for both IPv4 and IPv6. Practical examples will be discussed to clarify the concepts covered. The focus will be on several prominent research challenges: (a) the intersection of mobility and security: Interesting issues and challenges arise when trying to integrate mobility and security functions. Mobile IPv6 route optimization faces difficult security challenges; (b) simultaneous mobility: when both nodes are mobile, and both move at the same time, communications should not break. However, Mobile IPv6 fails to handle simultaneous mobility well; (c) handoff optimization: fast handoffs are usually very desirable. There have been many efforts to speed up handoffs.
Instructor: K. Daniel Wong, Malaysia University of Science and Technology, PJ, Selangor, Malaysia
TU10 Title: MIMO Detection: Theory and Practice
The adoption of multiple-input multiple-output (MIMO) techniques in wireless communications systems is fueled by the promises of high spectral efficiency and robustness to multipath fading. A key component of a MIMO system is the MIMO detector at the receiver, whose job is to recover the symbols that are transmitted simultaneously from multiple transmitting antennas. In practical applications, the MIMO detector is often the bottleneck for both performance and complexity.
This tutorial presents the basic principles of MIMO detection. We describe the fundamental problem, and present an overview of MIMO techniques that are used in practice. We begin with linear detection techniques, such as the zero-forcing and minimum-MSE detectors. We then describe the decision-feedback detector in its various guises, including the nulling-and-cancelling view, the matrix view, the Gram-Schmidt view, the whitened-matched filter view, and the linearprediction view. We compare the ZF and MMSE versions of these detectors. Afterwards we describe more advanced detection strategies, including multistage detectors and tree-based detectors like the sphere detector and its variations, as well as lattice-aided detectors. Lastly we will quantify the performance-complexity tradeoff for a variety of detection strategies.
This tutorial will provide an overview of MIMO detection as currently practiced, and it will identify emerging trends and current research in this area.
This tutorial will benefit practicing engineers and researchers who are interested in understanding and doing research in MIMO and related topics, particularly those who are engaged in the design of high-speed wireless data systems. MIMO is currently a very hot topic in both the academic and industrial communities and it is anticipated that this tutorial will be very well attended.
Instructor: John R. Barry, Georgia Tech
TU11 Title: Wireless Mesh Networks: From Theory to Practices and Standardization
In Wireless Mesh Networks (WMN), a group of wireless nodes can communicate with each other without the support of an infrastructure device. They are envisioned to provide a low-cost range extension to backhaul, and can also form an autonomous peer to peer multihop network if needed, especially in case of disaster recovery. Given the ease of deployment of such devices, there is a tremendous interest in the research community to develop a robust and efficient mesh solution. However, the very nature of multihop communication, and characteristics of wireless links makes the design of such scheme non-trivial. In this tutorial we will systematically explore the selected issues related to MAC and routing layers including spatial reuse, power save, and multipath routing among others. We will analyze different schemes proposed in the literature to enhance the performance of a WMN. In the second part of the tutorial we will cover the developments on the standardization effort in IEEE for wireless mesh networking, namely 802.11s. We will explain forwarding, MAC, and Interworking aspects of 802.11s. We conclude the tutorial by outlining some of the current and future research directions in this area. After attending this tutorial, attendees with a clear understanding of the mesh technology will be able to build their own WMN or test beds. The knowledge gained from this tutorial can be very helpful for researchers and engineers to build better protocols and products for WMNs.
Instructors: Dharma Agrawal and Nagesh S. Nandiraju , Department of Computer Science, University of Cincinnati
Hrishikesh Gossain, Mesh Networks Group, Motorola Inc.
WCNC 2007 HALF DAY TUTORIALS
Thursday 15 March 2007
8:30 - 12:30
Design and evaluation of antennas for communications with diversity and MIMO CANCELED
This tutorial addresses the design and evaluation of antennas for communications. The gain of antenna has a direct impact on the link performance including the spectral efficiency. The classical directive gain and its measurement are reviewed with the natural progression to the distributed gain and the diversity gain for antennas designed for multipath situations. With most links operating in multipath, multi-element antennas with high distributed gain and good diversity performance are required. Developing compact multi-element antennas with statistical performance measures requires convenient experimental evaluation techniques.
Instructor: Rodney Vaughan, School of Engineering Science, Simon Fraser University
TU06 Title: IP-Oriented QoS in the Next Generation Networks: application to wireless networks
Emerging Internet Quality of Service (QoS) mechanisms are expected to enable wide spread use of real time services such as VoIP and videoconferencing. The "best effort" Internet delivery cannot be used for the new multimedia applications. New technologies and new standards are necessary to offer Quality of Service (QoS) for these multimedia applications. Therefore new communication architectures integrate mechanisms allowing guaranteed QoS services as well as high rate communications.
The service level agreement with a mobile Internet user is hard to satisfy, since there may not be enough resources available in some parts of the network the mobile user is moving into. The emerging Internet QoS architectures, differentiated services and integrated services, do not consider user mobility. QoS mechanisms enforce a differentiated sharing of bandwidth among services and users. Thus, there must be mechanisms available to identify traffic flows with different QoS parameters, and to make it possible to charge the users based on requested quality. The integration of fixed and mobile wireless access into IP networks presents a cost effective and efficient way to provide seamless end-to-end connectivity and ubiquitous access in a market where the demand for mobile Internet services has grown rapidly and predicted to generate billions of dollars in revenue.
This tutorial covers to the issues of QoS provisioning in heterogeneous networks and Internet access over future wireless networks as well as ATM, MPLS, DiffServ, IntServ frameworks. It discusses the characteristics of the Internet, mobility and QoS provisioning in wireless and mobile IP networks. This tutorial also covers routing, security, baseline architecture of the inter-networking protocols and end to end traffic management issues.
Instructor: Pascal Lorenz, The University of Haute-Alsace
TU07 Title: Near-Capacity Wireless Multimedia Communications in the Iterative Detection Era
Wireless multimedia communication devices are becoming ever more powerful and sophisticated, as seen on television. Nonetheless, the provision of realistic "tele-presence" services requires a further quantum leap from the current state-of-the-art represented by the popular mobile telephone. Based on the presenters monographs and papers (www.ecs.soton.ac.ukpeoplelh) - he recent advances in this challenging field are reviewed, commencing with a portrayal of the related multimedia source codecs, advanced channel codecs and burst-by-burst adaptive modems, such as those used by the High-Speed Downlink Packet Access (HSDPA) mode of the third-generation (3G) wireless systems, including space time codecs and other MIMO systems.
Commencing with a review of the Shannonian information-theoretic design principles, powerful system design examples will be presented, which are capable of approaching the channel capacity. The limitations of the Shannonian lessons in the context of realistic fading, rather than Gaussian channels will be detailed. To elaborate a little further, most multimedia source signals are capable of tolerating lossy, rather than lossless delivery to the human eye, ear and other human sensors. The corresponding lossy and preferably low-delay multimedia source codecs however exhibit unequal error sensitivity, which is not the case for Shannon¹s ideal entropy codec. Numerous jointly optimised turbo transceiver designs capable of providing unequal error protection for MPEG-4 coding aided wireless video telephony and audio transmission will be highlighted, which exhibit a performance close to the channel capacity. Sophisticated multi-stage iterative detectors will be studied, which exchange extrinsic information across several detection stages, including Space-Time Trellis Coding (STTC) invoked for the sake of mitigating the effects of fading, as well as bandwidth efficient Turbo Trellis Coded Modulation (TCM) or Bit-Interleaved Coded Modulation (BICM). These multistage turbo systems require the employment of the powerful iterative receiver design tools referred to as three-dimensional (3D) Extrinsic Information Transfer (EXIT) Charts.
Instructor: Lajos Hanzo, School of ECS, Univ. of Southampton
TU08 Title: Routing in Delay Tolerant Mobile Ad Hoc Networks: Overview and Challenges
In mobile tactical ad hoc networks, nodes are constantly in motion and/or operate on limited power. When nodes are in motion, links can be obstructed by intervening objects. When nodes must conserve power, links are shut down. These result in intermittent connectivity. When no path exists between source and destination, network partition occurs. Examples of an intermittently connected network (ICN) are: a). An inter-planet satellite communication network where satellites and ground nodes may only communicate with each other several times a day, b). A sensor network where sensors are not powerful enough to send data to a collecting server or are scheduled to be wake/sleep periodically, c). A military ad hoc network where nodes (e.g. tanks, airplanes, soldiers) may move randomly and are subject to being destroyed. Applications in ICNs must tolerate delays beyond conventional IP forwarding delays and these networks are referred to as delay/disruption tolerant networks (DTN). New protocols specifically for DTNs must be developed as existing protocols designed for the Internet do not work properly.
Applications in DTNs include
- JPL¹s Inter-planet network,
- US Navy Seaweb Initiative: Enabling Undersea FORCEnet for cross-system, crossplatform, cross-mission, cross-nation interoperability
- UMass DieselNet: A Disruption-Tolerant Network Testbed
- US Marine Corps CONDOR‹Command and Control On-the-Move Network Digital Over-the-Horizon Relay.
Recently there has been much research activity in the emerging area of intermittently connected ad hoc networks and delay/disruption tolerant networks (DTN) (DARPA launched one in 2005). There are different types of DTNs depending on the nature of the network environment. Routing in DTNs is one of the key components in the DTN architecture proposed by the DTN research group. Therefore, researchers have proposed different routing protocols for different types of DTNs in the last few years. In this tutorial, we review the state of the art in DTN networks, especially routing protocols. We categorize these routing protocols based on information used. For deterministic time evolving networks, three main approaches are discussed: the tree approach, the space and time approach, and the modified shortest path approach. For stochastic time evolving networks, the following approaches are reviewed: the epidemic or random forwarding approach, predication or history based approach (including per contact routing based on one-hop information only and per contact routing based on average end to end information), the model based routing approach as well as approaches which control the movement of certain special nodes. Recent developments in erasure coding and network coding applied to DTNs are also discussed. As a case study, we will discuss how DTN technologies are applied to real DOD networks such as US Marine Corps CONDOR‹Command and Control On-the-Move Network Digital Over-the-Horizon Relay. CONDOR is a short term bridging strategy to link existing tactical radio and data networks and to provide an over-the-horizon communications capability to link line-of-sight radio systems that have moved beyond line-of-sight or that precluded by terrain features or other obstacles. The tutorial also identifies open research issues and intends to motivate new research and development in this area.
Instructor: Zhensheng Zhang, San Diego Research Center
TU09 Title: MIMO for Multiuser Wireless Systems
Multiple antenna (MIMO) techniques are an essential component of any contemporary wireless communication system because they can significantly improve the performance over conventional single-antenna links. While MIMO techniques are relatively well understood at the link level, the interaction of multiple MIMO links and their impact on performance at the system level necessitate fundamentally new investigations. In this tutorial, we investigate the theoretical foundations of MIMO networks consisting of multiple simultaneous MIMO links and to apply these principles in the design of next-generation wireless networks.
About ten years ago, the information theoretic foundations of MIMO techniques were developed and showed the promise of using multiple antennas at both the transmitter and receiver of a wireless link. An enormous amount of research ensued to develop practical techniques for achieving these promised gains. Within the last few years, the information theory community has again made significant breakthroughs, this time in the understanding of multiuser MIMO systems. Currently in industry, new wideband wireless standards, including EV-DO Rev C, UMTS LTE, and WiMax, are under development to meet the insatiable demands for high-rate, ubiquitous wireless services. For all of these standards, MIMO technology will play an integral role in meeting the aggressive performance requirements for increased data rates, decreased latency, and improved coverage.
Motivated by the confluence of these two events‹the emergence of multiuser MIMO theory and the development of commercial MIMO-based systems‹we propose to connect the two worlds in a tutorial that addresses both theory and practice. It would provide a systematic survey of MIMO systems, starting with a review of MIMO link-level techniques and conventional single-antenna system-level techniques, summarizing the latest results in multiuser MIMO systems and developments in cross-layer techniques, and applying these techniques to the analysis and design of future packet-based wireless networks.
Instructor: Howard Huang, Bell Labs, Lucent Technologies, Holmdel, NJ
TU12 Title: Ultra-wide Bandwidth Systems: Theory and Practice
UWB transmission systems have gained significant interest in the scientific, commercial and military sectors. Wide bandwidth provides fine delay resolution, robustness against fading, and superior obstacle penetration, making UWB technology a viable candidate for reliable communications in dense multipath environments. UWB transmission systems potentially allow low-cost production and reuse of already populated spectra; and hence they are currently under consideration for a wide variety of applications such as high data-rate communications and low data-rate sensor networks. With its low probability of detection and anti-jam capabilities, UWB also has applications in military operations. Rulings concerning UWB emission masks by the US Federal Communications Commission, the Japanese Ministry of Internal Affairs and Communications, and the Korean Ministry of Information and Communication have opened the way for coexistence with traditional and protected radio services, as well as the potential use of UWB transmission without allocated spectra. This tutorial will provide the fundamentals of UWB systems, motivating applications, recent developments, and regulatory issues.
Instructor: Moe Win and Chia-Chin Chong, MIT, USA