Exploiting caching in heterogeneous mobile environment
Sparse connectivity, limited energy, and restricted memory of Mobile Hosts (MHs) are the main characteristics of today's Mobile Ad hoc NETwork (MANET). Present wireless technology is now enabling MHs not only to have multi-hop communication among themselves, but also to have direct connection with an Access Point (AP) also. The emergence of such heterogeneous technologies brings cooperative caching to reality wherein MHs can access data items from caches at MHs in their neighborhood and can drastically minimize query latency. This key technique reduces the number of uplink channel requests, alleviates server load, and increases data availability. In this paper, we assume a heterogonous mobile environment where combination of ad hoc communication and infrastructured APs can be used to better manage the data needs of MHs through cooperative caching. We call such an environment as Cooperation-based Access Point MANET (CAPMANET). We present a Hop-Oriented Cooperative Caching (HOCC) scheme for CAPMANET which helps in reducing the communication overhead and the query latency. HOCC employs a hybrid Pull with Push (PwP) mechanism to maintain data consistency. Simulation results demonstrate that HOCC outperforms the pure push and pure pull-based strategies by taking advantages of underlying characteristics and avoiding associated weaknesses. Copyright (c) 2007 John Wiley & Sons, Ltd.
access point cooperative cache query latency cache invalidation heterogeneous environment multi-hop network