Optimal packet length and recursive mode decision for live video streaming over ad hoc wireless networks

For live video streaming over ad hoc networks, high bandwidth requirements are coupled with delay constraints. Based on the queuing model, we propose an analytical method to figure out the optimal packet length for each link. The approach captures the influence of link capacity, source-video rate and header overhead, which can be used to minimize the end-to-end delay. It also guarantees stable video playout and is practical. Packet losses over ad hoc wireless networks often occur in bursts, which may cause substantial degradation to the transmitted video quality. To achieve robust video streaming over a bandwidth-limited ad hoc network, we propose a recursive mode decision algorithm, called CROPE (Conditional recursive optimal pixel estimate). We intend to make our H.264 error-resilient encoder capture the bursty nature of the packet losses and effectively stop error propagation. Based on the conditional probability of burst error, CROPE improves the accuracy of the estimation when compared to ROPE (Recursive optimal pixel estimate)The simulation results under different simulation conditions show that the proposed algorithm has robust error resilient ability and good adaptability. It yields consistent and significant gains over the competing methods in a wide range of bitrate, transition probability and burst length. Moreover, CROPE has low computational complexity and is suitable for multicast applications.