Adaptive File Replication Algorithm for Wireless Mesh Networks

Popular files could exhaust the capacity of the file owner node, leading to low efficiency in P2P file sharing systems. File replication is an effective method to deal with this problem by distributing load over replica nodes. Recently, numerous file replication methods have been proposed for P2P content delivery networks on the Internet. However, due to mobility and resource constraints in the wireless networks, these replication techniques designed for wired networks may not be applicable to the wireless networks. Aiming at the issue of file replication, an adaptive file replication scheme is proposed for wireless mesh networks in this paper. Based on file popularity and node’s utilization, the optimal number of replicas needed for each file is determined automatically by the responsible node in a distributed way. By using multiple-adjacency codes based on hypercube, a perfect placement scheme is achieved for each file replica, thus, it reduces access hops between the file requester node and some nearby nodes, which can provide the requesting file. Furthermore, a solution is adopted, which autonomously decides whether to replicate file, and adaptively adjusts the file replica nodes based on time-varying file popularity and node’s load in the P2P systems having dynamic characteristics. Simulation results demonstrate that our proposed algorithm performs much better than similar ones, and yield significant improvement on the effectiveness in terms of both file access cost and overloaded nodes reduction.