Data caching can significantly improve the efficiency of information access in a wireless ad hoc network by reducing the access latency and bandwidth usage. The problem of optimal placement of caches to reduce overall cost of accessing data is motivated by the following two defining characteristics of ad hoc networks. Firstly, the ad hoc networks are multi hop networks without a central base station. Thus, remote access of information typically occurs via multi-hop routing, which can greatly benefit from caching to reduce access latency.
Secondly, the network is generally resource constrained in terms of channel bandwidth or battery power in the nodes. Caching helps in reducing communication, which results in savings in bandwidth as well as battery energy. The problem of cache placement is particularly challenging when each network node has limited memory to cache data items.