Topology control for fault-tolerant communication in highly dynamic wireless networks

ó Energy efciency and fault-tolerance are the most important issues in the development of next-generation wireless ad hoc networks and sensor networks. Topology control as a low level service (typically below the traditional layer struc- ture) governs communication among all nodes and is hence the primary target for increasing connectivity and saving energy. In this paper, we present an improvement of our topology control algorithm for very dynamic networks and low power devices (e.g. sensor nodes). The algorithm constructs a fault-tolerant topology for energy- efcient and fault-tolerant multi-hop communication in a two-tier network consisting of a large number of wireless nodes and a few gateway nodes (e.g. base stations re- sponsible for exchanging data with other networks). Using only local information, like distance/channel attenuation to neighbors, our fully distributed algorithm ef- ciently constructs and continuously maintains a k-regular overlay graph that guar- antees low total transmission power, is k-node-connected and ensures failure local- ity. It automatically adapts to a dynamically changing environment, is guaranteed to converge, builds a hierarchy of clusters that reects the node density and exhibits good performance as well.