An Improved Cache Invalidation Policy in Wireless Environment Cooperate with Cache Replacement Policy Based on Genetic Programming

摘要

Communication between mobile clients and database servers in wireless environment suffers from; the user's movement, disconnected modes, lots of data updates, low battery power, cache size limitation, and bandwidth limitation. Caching is used in wireless environment to overcome these challenges. The aim of this effort is to present enhanced invalidation policy that cooperates with a new cache replacement technique by using genetic programming to select the items that will be removed from the cache for improving data access in the wireless environment. Cooperation between servers and mobile clients to enhance data availability. Each mobile client Collects data like access probability, size, and next validation time and uses these parameters in a genetic programming method for selecting cached items to be removed when the cache is full. The experiments were carried using NS2 software to evaluate the efficiency of the suggested policy, and the results are compared with existing cache policies algorithms. The experiments have shown that the proposed policy outperfomed the LRU by 24% in byte hit ratio, and 11% in cache hit ratio. It is concluded that the presented policy achieves well than other policies.