Energy-Efficient Cache Invalidation in Wireless Mobile Environment

Abstract

Caching at the mobile client is a potential technique that can reduce the number of uplink requests, lighten the server load, shorten the query latency and increase the data availability. A cache invalidation strategy ensures that any data item cached at a mobile client has same value as on the origin server. Traditional cache invalidation strategies make use of periodic broadcasting of invalidation reports (IRs) by the server. The IR approach suffers from long query latency, larger tuning time and poor utilization of bandwidth. Using updated invalidation report (UIR) method that replaces a small fraction of the recent updates, the query latency can be reduced. To improve upon the IR and UIR based strategies, this chapter presents a synchronous stateful cache maintenance technique called Update Report (UR). The proposed strategy outperforms the IR and UIR strategies by reducing the query latency, minimizing the disconnection overheads, optimizing the use of wireless channel and conserving the client energy.