An Energy Conserving Cooperative Caching Policy for Ad Hoc Networks

Without pre-existing infrastructure, a Mobile Ad Hoc Network (MANET) can be easily deployed in a hostile environment such as a military operation area or an area undergoing disaster recovery. With limited bandwidth, the data caching technique may be useful to enhance the performance of a MANET. The cooperative caching scheme is shown to be suitable for MANETs. With cooperative caching schemes, each node shares its cached data items with other nodes in the network to improve the data availability of the network. Unfortunately, the existing cooperative caching schemes did not consider the energy consumption of a mobile node. A mobile node with limited residual energy may exhaust its power very quickly. As a result, the data availability of the network will be degraded. In this paper, we propose an energy conserving cooperative caching scheme which allows a mobile node with more residual energy to cache more data items for other nodes than a mobile node with less residual energy. Simulation results show that the proposed scheme enhance the data availability by reducing the response time of a query and extending the lifetime of the network.