Maximizing battery life routing in wireless ad hoc networks

Most wireless ad hoc networks consist of mobile devices which operate on batteries. Power consumption in this type of network therefore is paramount important. To maximize the lifetime of an ad hoc network, it is essential to prolong each individual node (mobile) life through minimizing the total transmission energy consumption for each communication request. Therefore, an efficient routing protocol must satisfy that the energy consumption rate at each node is evenly distributed and at the same time the total transmission energy for each request is minimized. To devise a routing protocol meeting the above two conflict objectives simultaneously is very difficult due to the NP hardness of the problem. Instead, an approximation solution is desirable and appreciated. In this paper, we focus on developing power-aware routing algorithms which find routing paths that maximize the lifetime of individual nodes and minimize the total transmission energy consumption, thereby prolong the life of the entire network. In particular, for an ad hoc network consisting of the same type of battery mobile nodes, two approximation algorithms are proposed. The running times of the proposed algorithms are determined by the accuracies of the approximation solutions. Compared with a previously known result, our algorithms have less energy overhead and can be implemented in a distributed environment. For an ad hoc network equipped with different types of battery mobile nodes, a new power-aware routing protocol is proposed, and the algorithm can also be implemented in a distributed manner.