|With rapid growth of wireless markets worldwide and expanding interest in broadband wireless networks (BWA), practitioners and researchers alike are looking to devise ways to support a broad mix of users and traffic types with differing service requirements over such networks.
The main theme of this workshop/tutorial will be to elucidate medium access control (MAC) layer operation and cross-layer design techniques for providing quality-of-service (QoS) in wireless broadband networks. We will use the recently approved IEEE 802.16 standard as an example, for two important reasons:
- The rich feature-set it presents, and the flexibility it provides the system/network designer in choosing various schemes for scheduling traffic, while accounting for interactions between an advanced PHY (physical layer) and the corresponding MAC (data link).
- Growing interest from operators worldwide in this emerging technology, due to the prospects of using it in a variety of applications, such as wireless data backhaul or in regions of the world where there is little or no wired infrastructure.
The IEEE 802.16 standard for fixed and mobile wireless broadband access systems is a complex standard with many features to enable data services over BWA links. These include, for instance, longer range (of 10s of miles), advanced coding and modulation schemes (OFDM, OFDMA) and power control at the physical layer, and the definition of traffic classes and advanced automatic-repeat request (ARQ) schemes at the MAC layer, to name a few.
From a traffic scheduling perspective, one must understand the key features of the standard that relate to QoS at the MAC layer, and develop a range of alternative QoS architectures that can provide the required performance. It also requires developing insights into the role/functions of the principal components of these architectures. For example, base-station (BS) or subscriber-station (SS) schedulers, traffic request classifiers, contention estimators, and so on.
With this perspective, the specific topics to be addressed in our tutorial include:
i. Introduction to the 802.16 wireless broadband standard – the 802.16 protocol stack; key features of the PHY and MAC layers
ii. MAC layer details – packing/fragmentation, QoS, ARQ schemes
iii. Scheduling services (or traffic classes) in 802.16, and their relation to QoS
iv. Review of alternative QoS architectures for providing guarantees in 802.16-based networks
v. Role of cross-layer design – benefits, pitfalls, recommended practices
vi. Scheduling schemes for service guarantees in 802.16-based networks; presentation of initial performance results of selected schemes, and open issues
vii. Applications of the principles discussed to other technologies
Even though the 802.16 standard is used as an example, much of the principles and concepts discussed will apply to other high-speed wireless data systems as well. For example, the 3G wireless UMTS (Universal Mobile Telephone Service) or HSDPA (High-Speed Downlink Packet Access) systems.
Dr. Vishal Sharma
Vishal Sharma (B. Tech. (EE), IIT Kanpur, 1991, M.S. (Signals & Systems), M.S. (Computer Engg.), and Ph.D. (ECE) University of California Santa Barbara,1993, 1993, and 1997), has 15+ years of diverse research and industry experience in networking and telecom technologies, with a focus on system architecture, protocol design, system analysis and optimization, software prototyping, and network planning & algorithms. He is a core contributor to the generalized MPLS standards developed at the IETF and has several patents in process. Dr. Sharma is Senior Member, IEEE, Fellow, IETE (The Institution of Electronics and Telecommunication Engineers, India), a Subject Matter Expert at the MPLS-Frame Relay-ATM Alliance, on Scientific Committees of the MPLS World Congress and MPLSCon, and on the TPCs of several international conferences. He is a frequent Chair, speaker, invited panelist, and educator in industry/academia in the US and abroad, having delivered over 60+ invited talks, seminars, short courses, workshops, and tutorials. He serves as a Principal Consultant with Metanoia, Inc. and, currently, is also associated with the Department of EE at IITBombay, where he guides a research group on wireless networking, whose notable ongoing activities are: design of efficient scheduling schemes for 802.16-based wireless broadband networks, a test-bed for investigating infrastructure security in 2.5 and 3G wireless cellular data networks, and an ad-hoc network test-bed for evaluating routing protocols. His current interests are in metro/access network design and planning, traffic management and QoS in broadband wireline/wireless networks, and novel architectures for advanced IP/TDM or hybrid systems.
Dr. Abhay Karandikar
Abhay Karandikar earned his M.Tech. and Ph.D degrees in Electrical Engineering from the Indian Institute of Technology, Kanpur in 1988 and 1994, respectively. From 1994-97, he worked at the Center for Development of Advanced Computing (C-DAC), an Indian Government initiative in supercomputing. As Team Coordinator, he led the team on high-speed interconnection network design of the PARAM 9000 supercomputer, and several other high-speed networking projects in C-DAC. He joined the Department of Electrical Engineering, IIT Bombay in April 1997, where he is currently Associate Professor. At IIT Bombay, he started many technology development projects, including the one on MPLS. He has supervised many graduate theses and published in several conferences and journals. He co-founded the venture backed company Eisodus Networks that focuses on broadband access to cater to emerging India- and Asia-Pacific markets. His research interest include: quality of service guarantees in communications networks, broadband wireless networks, and digital system design. He has consulted extensively for industries in the areas of communications and networking. Dr Karandikar has served on the technical program committees of several national and international conferences, like ADCOM, HiPC, WCNC, and ICBN, and has been a regular reviewer for IEEE Transactions, IEEE Communication Letters, and IEE Proceedings. His research group at IIT Bombay is currently focused on cross-layer design issues in wireless networks, and is investigating scheduling and admission control in wireless networks, resource reservation in next-generation cellular networks, and energy-efficient MAC protocols for ad-hoc networks.