Connectivity Ascertainment based Distributed Topology Control for Wireless Sensor Networks

Most sensor nodes usually have the ability to vary their own wireless transmission power. Hence they have the potential to control the network topology, which is the pattern of links connecting pairs of nodes in a network. In this paper, we propose a connectivity ascertainment based distributed topology control algorithm. The algorithm draws out the potential from nodes for constructing an energy-efficient network topology. Each node performs the algorithm and makes local decisions about its transmission power; these local decisions minimize the total transmission power of the network, while maintaining network connectivity. Specifically, each node ascertains the existence of an actual path that is a substitute for a wireless link to an own edge node, which requires the maximum transmission power among its own neighbors. To contribute to path ascertaining, the other nodes use locally-collected information. If a node can ascertain the existence, it decides to remove the wireless link to the edge node by reducing the transmission power. The node targets a new edge node from among its own current neighbors and performs the same process until there are no substitute paths to the target. We show that these local decisions collectively guarantee global connectivity and minimize the total transmission power of the network. We also evaluated the performance of our algorithm on terms of network connectivity and transmission power reduction using simulation studies.