HAGR: Hole Aware Greedy Routing for Geometric Ad Hoc Networks

In geometric ad hoc networks, mobile nodes´ locations facilitate greedy routing algorithms to discover the optimal or shortest paths. When void zones (holes) present, greedy routing algorithms could fail due to the local minimum problem. To solve this problem, existing geographic routing algorithms use face routing strategies based on the planarization of the underlying network topology. We notice that during the planarization process, some single-hop links are removed from the network, which implies that some packets have to be delivered around faces even if a single-hop link is available. To solve this problem, we present Hole Aware Greedy Routing (HAGR), a novel routing protocol for geometric ad hoc networks in this paper. First, we define the concept of hole and formulate the problem resulting from the planarization process. Next, we propose the hole detection algorithm and hole advertisement algorithm. Then, we propose the greedy routing algorithm which uses the hole information. Finally, by analysis, we conclude that the HAGR protocol can increase the greedy algorithm´s efficiency without high overhead and complexity.