12/28/2003CNSF Workshop Localized Algorithms and Their Applications in Ad Hoc Wireless Networks Jie Wu Dept. of Computer Science & Engineering Florida Atlantic University Boca Raton, FL 33431

12/28/2003CNSF Workshop Classification of Communication Networks Wired Networks –LAN, MAN, WAN, and Internet Wireless Networks –Infrastructured networks (cellular networks) –Infrastructureless networks (ad hoc wireless networks)

12/28/2003CNSF Workshop Wired/Wireless Networks

12/28/2003CNSF Workshop Wireless and Mobile Networks 200 million wireless telephone handsets (purchased annually) A billion wireless communication devices in use The first decade of 21 st Century: mobile computing "anytime, anywhere"

12/28/2003CNSF Workshop Self-organizing: without centralized control Scarce resources: bandwidth and batteries Dynamic network topology Unit disk graph models: host connection based on geographical distance Characteristics

12/28/2003CNSF Workshop Unit Disk Graph A simple ad hoc wireless network of six wireless mobile hosts.

12/28/2003CNSF Workshop Mobility management –Addressing and routing Location tracking –Absolute vs. Relative, GPS Network management –Merge and split Resource management –Network resource allocation and energy efficiency QoS management –Dynamic advance reservation and adaptive error control techniques Major Issues in Ad Hoc Networks

12/28/2003CNSF Workshop MAC protocols –Contention-base, controlled Applications and middleware –Measurement and experimentation Security –Authentication, encryption, anonymity, and intrusion detection Error control and failure –Error correction and retransmission, deployment of back-up systems Major Issues in Ad Hoc Networks (Cont’d.)

12/28/2003CNSF Workshop Localized Algorithms (Estrin, 99) Processors (hosts) only interact with others in a restricted vicinity. Each processor performs exceedingly simple tasks (such as maintaining and propagating information markers). Collectively these processors achieve a desired global objective. There is no (or limited) sequential propagation of information.

12/28/2003CNSF Workshop Localized Algorithms (Con’t) Differ from traditional distributed algorithms Complexity –Communication: number of rounds –Communication: size of message –Computation: plays a lesser rule Quality –Average case: probabilistic analysis/simulation –Worst case: bound/approximation ratio

12/28/2003CNSF Workshop Application I: Connected Dominating Set (CDS) (Wu and Li, 1999) CDS as a virtual backbone Marking process: A node is marked true if it has two unconnected neighbors.

12/28/2003CNSF Workshop Marking Process (Cont’d.) A sample ad hoc wireless network

12/28/2003CNSF Workshop Application II: Broadcasting (Wu and Dai, 2003 and 2004) Promiscuous receive mode Coverage & efficiency Flooding: each node forwards the message once s u v w (a) s u v w (b) s u v w (c)

12/28/2003CNSF Workshop Application II: Broadcasting (Con’t) Localized solution via self-pruning (INFOCOM 2003) Localized solution via neighbor designation (ICDCS 2003) Mobility management and consistent view (INFOCOM 2004) Computation complexity reduction in dense mode (ICDCS 2004)

12/28/2003CNSF Workshop A Sample Broadcasting (n=100, d=6, r=16, k=2)

12/28/2003CNSF Workshop Other Applications Energy-Efficient Communication MAC layer protocols Topology control Directional antenna Sensor coverage Data gathering and dissemination …

12/28/2003CNSF Workshop Security in Ad Hoc Networks Key management Routing security Light-weight cryptography Intrusion detection Trust: incentive-based

12/28/2003CNSF Workshop Cross-Disciplinary Issues NSF Sensor Network Program (March, 2003) Sponsored by multiple divisions/programs (including CISE) Encouraging multi-disciplinary team effort 1,000 submissions with an acceptance rate of around 5%

12/28/2003CNSF Workshop Example: Multi-Disciplinary Team Hitch-hiking Model (INFOCOM 2004) Energy-efficient design in sensor networks Multiple institutions: UMass- FAU Multiple disciplines physical layer MAC layer network layer

12/28/2003CNSF Workshop Vision of the Field Convergence of Multiple Disciplines –Parallel processing –Distributed systems –Network computing Wireless network and mobile computing as an important component in Cyberinfrastructure and Cybertrust

12/28/2003CNSF Workshop Vision of the Field Ultimate Cyberinfrastructure Petascale computing, exabyte storage, and terabit networks Network-Centric Supernetworks: networks are faster than the computers attached to them Endpoints scale to bandwidth-match the network with multiple-10Gbps lambdas

12/28/2003CNSF Workshop Major Conferences in the fields General: IEEE INFOCOM Mobile Computing: ACM MobiCom Ad Hoc Networks: ACM MobiHoc Distributed Systems: IEEE ICDCS Sensor Networks: IEEE MASS (Mobile Ad- hoc and Sensor Networks)

12/28/2003CNSF Workshop Some Related Events IEEE Computer –Special issue on Ad Hoc Networking –Feb. 2004, guest editors: J. Wu. & I. Stojmenovic NSF Workshop on Theoretical Aspects of Ad hoc, Sensor, and Peer-to-Peer Networks –Feb. 2004, –Book published by CRC and special issue in JPDC