Shortest Anypath Routing and Applications to Low-Power Wireless Networks

In many networks, it is less costly to transmit a packet to any node in a set of neighbors than to one specific neighbor. A well-known instance is with unreliable links, where the probability that at least one node out of n receives a packet increases with n. This observation was previously exploited, by modifying single-path routing to assign to each node group of candidate next-hops for a particular destination. This paper introduces a general formulation of the shortest anypath routing problem: how to assign a set of candidate relays at each node for a given destination, such that the cost of forwarding a packet to the destination is minimized. The key is the following tradeoff: on the one hand, increasing the number of candidate relays decreases the forwarding cost, but on the other, this increases the likelihood of “veering” away from the shortest-path route.