Research Projects

Path Selection for Video Streaming over Wireless Ad Hoc Networks

*** THIS PROJECT IS NO LONGER ACTIVE ***

Wei Wei and Avideh Zakhor

There are many challenges to support video communication over wireless ad hoc networks. An end-to-end connection route in wireless ad hoc networks generally consists of multiple wireless links, which has much smaller throughput and higher random packet loss than single hop wireless connections in a wireless network with an infrastructure. Due to the mobility of wireless nodes, the established connection routes between senders and receivers are likely to be broken during video transmission, causing interruptions, freezes, or jerkiness in the received video signal. These constraints and challenges, in combination with the delay and loss-sensitive nature of video applications, make video communication over wireless ad hoc networks a challenging proposition. In this project, we propose an optimal scheme for selecting two node-disjoint paths, so as to minimize concurrent Packet Drop Probability (PDP) over all possible path pairs, i.e., maximizing the worst video quality. We propose a model to estimate the concurrent PDP of two node-disjoint paths. We show that the above optimization is an NP-hard problem. We then propose a heuristic protocol based on our path selection model, whose performance is shown to be close to that of the "optimal routing," while significantly outperforming other heuristic protocols. We use both NS simulations and actual experiments to evaluate the proposed scheme.