Plasma Anypath Routing in Wireless Mesh Networks

We present a new routing paradigm that generalizes opportunistic routing for the multi-gateway case. In plasma anypath routing, each packet is delivered over the best available path to one of the gateways. The choice of the path and gateway for each packet is not made beforehand by the source node, but rather on-the-fly by the mesh routers as the packet traverses the network. To our knowledge, the problem of gateway anycasting via anypath routing has not been explored before. We provide a theory capable of jointly optimizing the transmission rate and the set of next hops to reach the best subset of gateways. We propose an optimal distributed routing algorithm as well as a load-balancing technique to disperse the network traffic among multiple gateways. We validate our proposal with traces from an 802.11b testbed. Our results show that plasma anypath routing outperforms multirate anypath routing, with a maximum gain of 31% for two gateways and 64% for four gateways. We also show that the load can be distributed among the gateways and that plasma anypath routing is robust to wireless link fluctuations over long periods of time.