Video transmission over wireless multihop networks using opportunistic routing
Wireless multihop networks comprise of mobile or stationary stations interconnected via an ad hoc multihop path. The dynamically self-organized and selfconfigured nature of such network provides a flexible alternative in a variety of contexts where the deployment of a fixed infrastructure may be impractical. While this type of network provides new opportunities in multimedia streaming, the high rate requirement coupled with stringent time constraints poses a certain range of challenges in deploying high quality video services. This paper presents an analytical model to study the performance of multihop video streaming using opportunistic routing, an emerging technique that achieves high throughput in the face of volatile wireless links. Specifically, we use a discrete-time Markov chain to model the expected number of transmissions needed for a successful delivery in a multihop network. This model produces a closed-form expression that is later validated by the Monte-Carlo simulation. Using the proposed model, we compare opportunistic routing with the traditional routing method which considers the best predetermined multihop path. We demonstrate performance gains in throughput, latency, as well as decoded video quality from adopting opportunistic routing. The problem of out-of-sequence delivery inherently resulted from opportunistic communication is also discussed.