Density-Based Anycast: A Robust Routing Strategy for Wireless Ad Hoc Networks

Existing anycast routing protocols solely route packets to the closest group member. In this paper, we introduce density-based anycast routing, a new anycast routing paradigm particularly suitable for wireless ad hoc networks. Instead of routing packets merely on proximity information to the closest member, density-based anycast routing considers the number of available anycast group members for its routing decision. We present a unified model based on potential fields that allows for instantiation of pure proximity-based, pure density-based, as well as hybrid routing strategies. We implement anycast using this model and simulate the performance of the different approaches for mobile as well as static ad hoc networks with frequent link failures. Our results show that the best performance lies in a tradeoff between proximity and density. In this combined routing strategy, the packet delivery ratio is considerably higher and the path length remains almost as low than with traditional shortest-path anycast routing.