Two-Hop Two-Path Voice Communications Over a Mobile Ad-Hoc Network

We consider two-hop communication of a delay- sensitive, memoryless Gaussian source over two independent paths in an ad-hoc network. To capture the behavior an ad-hoc network we combine a path availability model and a physical layer packet loss model. The path availability model includes the effect of path failures due to node mobility and route switching delays while the physical layer model accounts for the losses in the wireless channel. An analysis using the path availability model reveals potentially long connection down times due to path failures, suggesting that path diversity may be essential to support voice communications over a mobile ad-hoc network. We compare the performance of a few path diversity based communication methods involving multiple description coding and single description coding in an ad-hoc network with packet losses due to path failures and the physical channel.