Instructor: Luiz DaSilva and Vivek Srivastava, Virginia Tech, USA

The tutorial will introduce topics in wireless networks and mobile systems that are fundamental to three areas of current commercial and academic interest: (1) wireless ad hoc networks, including the link and network layers; (2) wireless "hot spots"; and (3) WLAN security.

For wireless ad hoc networks, we will introduce the basic operation of IEEE 802.11b (or WiFi) wireless local area networks, with particular emphasis on the use of IEEE 802.11b in ad hoc mode (without infrastructure). We will present the well known hidden node problem that can limit system performance and discuss the use of Request-to-Send (RTS) and Clear-to-Send (CTS) signaling in the IEEE 802.11 multiple access control standard to overcome the hidden node problem. A demonstration and case study, including a description of the experimental set-up and empirical results will illustrate the tradeoffs involved in enabling virtual carrier sensing. Attendees will learn how to configure a wireless local area network (WLAN) in ad hoc (infrastructure-less) mode and control the use of RTS/CTS signaling. We will also introduce the concept of routing in mobile ad hoc networks (MANETs) and use one MANET routing protocol, the Optimal Link State Routing (OLSR) protocol, as an example to make these concepts more concrete. We will use a case study and demonstration to show multi-hop communications in an ad hoc network and allow participants to monitor the operation of a MANET routing protocol.

For wireless hot spots, we will introduce the concept of wireless hot spot services for both subscription-based and open access service models. We will introduce a network architecture for a practical wireless hot spot service, including the use of Network Address Translation (NAT) to allow the use of private addresses for the hot spot service. We will also discuss security issues, including authentication of users and privacy of information. We will also use this opportunity to address more general security issues in wireless local area networks and IEEE 802.11 in particular. A third demonstration will provide attendees with first-hand experience in setting up a WiFi hot spot.

For wireless security in IEEE 802.11 networks, we will highlight some of the security vulnerabilities that can be exploited in launching a denial of service attack on the network. We will also explain some of the basic security concepts such as ARP cache poisoning and intrusion detection in the context of wireless networks and present a case study that illustrates the operation of an open-source wireless intrusion detection system, Kismet. A fourth and final demonstration will illustrate a denial-of-service attack by a rogue access point.

Luiz A. DaSilva joined Virginia Tech's Bradley Department of Electrical and Computer Engineering in 1998, where he is now an Associate Professor. He received his Ph.D. in Electrical Engineering at the University of Kansas and previously worked for IBM for six years. Dr. DaSilva's research interests focus on performance and resource management in wireless mobile networks and Quality of Service (QoS) issues. He is currently involved in funded research projects in the areas of QoS interoperability and policy-based network management, application of game theory to model mobile ad-hoc networks (MANETs), heterogeneous MANETs employing smart antennas, and pervasive computing, among others. Dr. DaSilva has published over forty refereed papers in journals and major conferences in the communications and computer areas. Current and recent research sponsors include NSF, the Office of Naval Research, the U.S. Customs Services, Intel, and Microsoft Research, among others. He is a member of the Center for Wireless Communications (CWT), associated faculty at the Mobile and Portable Radio Research Group (MPRG), and a member of the Governing Board of the NSF-funded Integrated Research and Education in Advanced Networking (IREAN) program at Virginia Tech. Dr. DaSilva is a senior member of IEEE, a member of ASEE, and a past recipient of the ASEE/IEEE Frontiers in Education New Faculty Fellow award. He frequently teaches distance and distributed courses on network architecture and protocols and on mobile and wireless networking. Together with Scott Midkiff and Ing-Ray Chen and with support from Intel, Dr. DaSilva developed an innovative hands-on course in wireless networks and mobile systems. Dr. DaSilva is serving as the co-technical program chair of the 2004 International Conference on Computer Communications and Networks (ICCCN) and has served on numerous other technical program committees.

Vivek Srivastava is pursuing his PhD in Computer Engineering at Virginia Tech. His research applies game theory to the analysis of the effects of varying node participation in ad hoc networks. He recently co-authored, with Dr. Luiz DaSilva, the paper "Node Participation in Ad Hoc and Peer-to-Peer Networks: A Game-theoretic Formulation," (accepted to the Workshop on Games and Emergent Behavior in Distributed Computing Environments, 2004). As a part of his research, he worked on the design and evaluation of a delivery based reputation scheme for ad hoc networks (DEBRA). He co-authored a paper and a poster describing the results of that work. He designed laboratory experiments and served as a laboratory teaching assistant for the innovative hands-on 'Mobile and Wireless Systems Design' course at Virginia Tech in Spring 2003. He has been an active student member of the IEEE Communications society (Northern Virginia section) since 2001. His other interests include "playing" with new wireless devices and reading.

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