Cooperative topology control with adaptation for improved lifetime in wireless ad hoc networks

Topology control algorithms allow each node in a wireless multi-hop network to adjust the power at which it makes its transmissions and choose the set of neighbors with which it communicates directly, while preserving global goals such as connectivity or coverage. This allows each node to conserve energy and contribute to increasing the lifetime of the network. Previous work on topology control has largely used an approach based on considering only the energy costs across links without considering the amount of energy available on a node. Further, previous work has largely used a static approach where the topology is determined at the beginning of the network´s life and does not incorporate the varying rates of energy consumption at different nodes. In this paper, we address these weaknesses and introduce a new topology control algorithm that dynamically adapts to current energy levels at nodes. The algorithm, called Cooperative Topology Control with Adaptation (CTCA), employs a game-theoretic approach that maps the problem of maximizing the network´s lifetime into an ordinal potential game. This allows a node running the CTCA algorithm to make a sacrifice by increasing its transmission power if it can help reduce energy consumption at another node with a smaller lifetime. We prove the existence of a Nash equilibrium for the game. Our simulation results indicate that the CTCA algorithm extends the life of a network by more than 50% compared to the best previouslyknown algorithm.