Cache Replacement in Mobile Adhoc Networks

Caching of frequently accessed data in Mobile Adhoc NETwork (MANET) is a technique that can improve data access performance and availability. In the situation of sufficient cache space one may think of keeping all the data items in the cache. However, this has overhead in terms of multiple copies of same data distributed all over the network and there are chances of inconsistency of data among different nodes. The main objective of cooperative caching is the optimum utilization of cache by storing different data items in the cache of each Mobile Node (MN). By doing this, different sets of items are kept in the neighboring MNs. As and when some MN requires a data item which is not available with itself it may ask the neighboring nodes for the same. In this manner cooperative caching environment is created in MANETs. Cache replacement is required when certain items are to be stored in the cache, but MN does not have the sufficient space to store the incoming item. This paper proposes a Profit Based Replacement (PBR) where profit value is calculated for every item in the cache. Simulation experiments demonstrate that the PBR improves the cooperative caching performance in comparison to other conventional techniques.