Multimedia Support in Wireless Multihop Networks

Multimedia Support in Wireless Multihop Networks Ian D. Chakeres The network of the future will be comprised of countless cooperating wireless devices. This network will need to not only be capable of simple delay-tolerant packet delivery, but also delay and loss sensitive applications such as voice and video. To make this future a reality, new advances in the areas of wireless communication, multihop routing, and multimedia delivery must be developed. Our work in perceptive behavior, reactive routing, and adapted protocols addresses these challenges and offers significant contributions. Perceptive behavior is a class of mechanisms that empowers wireless devices to exchange information during normal packet delivery and to coordinate and communicate with other nearby devices, even though some of these devices may be outside of direct communication range. We develop techniques that leverage this capability and explore perceptive behavior in actual experiments as well as in simulation. Multihop routing enables communication between wireless devices that are outside direct transmission range. In the area of multihop reactive routing, we examine the Ad hoc On-demand Distance Vector (AODV) routing protocol and the evolution of the Dynamic MANET On-demand (DYMO) routing protocol. We define several routing protocol specifications, develop enhancements to enable variable participation in heterogeneous networks, investigate reactive routing design and implementation issues, and experimentally evaluate reactive routing both in the laboratory and in the field. Our work also describes several adaptations of the IEEE 802.11 MAC layer that enable delivery of multimedia with fewer packet transmissions and less delay. We investigate these adaptations in single and multihop networks with various network scenarios, voice encoders, and error rates. In addition, we share our tools to enable realistic multimedia evaluation in simulated and emulated wireless multihop networks. This thesis addresses current core challenges to make possible ubiquitous high quality networks of the future. Our research has shaped and will continue to shape the future of multimedia delivery in wireless multihop networks.