Broadcast based cache invalidation and prefetching in mobile environment

Abstract

Caching at mobile client is an important technique for improving the performance in wireless data dissemination. It can reduce the number of uplink requests, server load, query latency and can increase the data availability. Battery energy and limited bandwidth are two major constraints imposing challenges to the realization of caching at mobile clients. A cache invalidation strategy ensures that the data items cached in a mobile client are consistent with those stored on the server. In our invalidation scheme, to minimize uplink requests, all recently updated or requested items are broadcast immediately following the invalidation report. To further improve the caching performance, prefetching is used. Three update report strategies are presented to reduce average access time and minimize the client energy for cache invalidation. Simulation experiments show that the LCF strategy dramatically improves the average access time for mobile clients, reduces the number of uplink requests and conserves the client energy. © Springer-Verlag 2004.