The design and application of mobile awareness mechanism in wireless ad hoc networks without GPS

A mobile ad hoc network is a wireless multihop network without any existing infrastructure. Thus when one node wants to transmit data to another node, it should depend on other nodes to forward it. In such a networking environment, the movement of highly mobile nodes may frequently result in the link breakdown, thus causing network inefficiency and data loss. In this paper, we develop a simple heuristic mechanism to characterize the instant mobility of network nodes. We assume that all network nodes can move arbitrarily, and none of them is equipped with any positioning device (such as the GPS system). Each mobile node is (at any time) classified as either a low mobility node or a high mobility node. A mobile node estimates its own mobility type by comparing the signal strength of consecutive received messages sent by its low mobility neighboring nodes. It then broadcasts this mobility type information to its neighbors. The mobility estimation algorithm is thus fully distributed and self organized. We then apply the estimated mobility characteristics to the construction of the end-to-end routing path. Two methods of selecting low mobility nodes as the primary intermediate routing nodes are presented. Performance evaluations via simulations have demonstrated the robustness of such a mobile awareness algorithm.