Exploiting Distributed Source Coding for Multi-Hop Routing in Wireless Ad Hoc Networks

This paper presents a routing algorithm for wireless multi-hop ad hoc networks, which applies distributed source coding (DSC) and multi-path transport of data packets. DSC enables the relay nodes to efficiently encode the packets and helps the destination node to correctly decode the information from multiple erroneous copies of the same packet received via different paths. While in conventional communication systems packets with bit errors are discarded, in our design the relays are allowed to forward erroneous packets. In order to exploit DSC for ad hoc routing, we extend contention-based geographical forwarding (CBGF) to support multi-path packet transport and enable the joint decoder to recover transmission errors. Under harsh wireless conditions, the approach promises performance gains compared to the case without joint decoding. In order to evaluate the performance of CBGF, we define an evaluation framework that models the erroneous forwarding and joint decoding by an abstraction of the physical transmission. We assess the performance by simulations for a simple scenario with static nodes in terms of packet success ratio, end-to-end delay, and data traffic overhead, and compare the results with the baseline CBGF scheme without DSC-specific extensions and joint decoding.