A Pre-Processed Cross Link Detection Protocol for geographic routing in mobile ad hoc and sensor networks under realistic environments with obstacles

In mobile ad hoc and sensor networks, greedy-face-greedy (GFG) geographic routing protocols have been a topic of active research in recent years. Most of the GFG geographic routing protocols make an ideal assumption that nodes in the network construct a unit-disk graph, UDG, and extract a planar subgraph from the UDG for face routing. However, the assumption of UDG may be violated in realistic environments, which may cause the current GFG geographic routing protocols to fail. In this paper, we propose a Pre-Processed Cross Link Detection Protocol, PPCLDP, which extracts an almost planar subgraph from a realistic network graph, instead of a UDG, for face routing and makes the GFG geographic routing work correctly in realistic environments with obstacles. The proposed PPCLDP improves the previous work of Cross Link Detection Protocol, CLDP, with far less communication cost and better convergence time. Our simulation results show that the average communication cost and the average convergence time of PPCLDP are, respectively, 65% and 45% less than those of CLDP. This makes PPCLDP more desirable for mobile ad hoc and sensor networks.