RELADO: RELiable and ADaptive Opportunistic Routing Protocol for Wireless Mesh Networks

Opportunistic routing is considered as one of the most promising techniques to effectively limit performance degradation in wireless mesh networks caused by unpredictable channel variations and high loss rates. This paradigm defers the selection of the next hop after the packet reception to take advantage of any opportunity provided by broadcast transmissions. Most of the existing opportunistic approaches base the forwarder selection on end-to-end principles. However, in multi-hop wireless environments the cost of a path is not uniformly distributed over space, nor constant over time, hence even two equal-cost paths might present significantly different link quality distributions one from the other. This encourages the use of localized context to implement a more accurate selection of the possible forwarders after each packet transmission. Hence, in this paper the authors propose RELADO, an adaptive opportunistic routing protocol able to efficiently combine end-to-end with local information to ensure transmission resilience across the network. With this flexibility, RELADO is able to reduce packet loss by ensuring the best trade-off between throughput maximization and packet progress. An extensive set of ns2 simulations confirms the potentiality of RELADO to improve networkperformance when compared to both legacy unicast and opportunistic routing protocols.