Hit Optimal Cache for Wireless Data Access

One of the working requirements for many data access applications is the availability of the most updated information. In wireless communications service networks, remote data access consumes expensive wireless spectrum. An efficient cache can reduce the data access cost, by cutting down the amount of data transferred over the wireless channels. However, deploying an efficient cache in wireless environment is challenging, where caches are distributed all over the network and an update event invalidates all the cached copies of the updated data. In this paper, we formalize the concept of caching frequently accessed but infrequently updated data objects, and propose a cache replacement policy accordingly. To facilitate the replacement policy, two enhanced cache access policies are also proposed. The proposed caching policies are supported with strong theoretical analysis. We demonstrate that the policies guarantee an optimal number of cache hits in a caching system. Results from both analysis and our extensive simulations demonstrate that the proposed policies outperform the popular Least Frequently Used (LFU) scheme in terms of effective hits.