MORE: A Network Coding Approach to Opportunistic Routing
Opportunistic routing has the potential to substantially increase wireless network throughput. Prior work on opportunistic routing, however, requires tight node coordination. Different nodes in a network must have knowledge of which packets other nodes have received. Furthermore, the nodes have to agree on which nodes should transmit which packets. Such coordination becomes fragile in dense or large networks.This paper introduces MORe, a new opportunistic routing protocol that avoids node-coordination. Our design is rooted in the theory of network coding.Routers code packets going to the same destination and forward the coded versions. The destination decodes and recovers the original packets. This approach needs no coordination and provably maximizes network throughput. We have implemented our design and evaluated it in a 25-node testbed. Our results show that MORE provides an average throughput increase of 60% and a maximum of 10-fold, demonstrating that the theoretical gains promised by network coding are realizable in practice.