On the placement of web content replicas in WMNs

Abstract

Content replication and placement is an effective technique to improve data availability and enhancing network performance. This area received attention in Content Delivery Networks (CDNs), but is less explored by the research community in Wireless Mesh Networks (WMNs). A number of replica placement algorithms were specifically designed for CDNs, but they do not consider the special features of wireless networks such as insufficient bandwidth, low server capacity, contention to access the wireless medium, etc. In this paper, we propose a fully-fledged object replication and placement scheme for WMNs. In our model, each mesh router acts as a replica server with limited storage capacity. The challenge is to minimize the demand-weighted access cost by replicating popular objects and placing them at replica servers (mesh routers) as close as possible to the requesting mesh clients, while minimizing the number of replicas subject to the storage capacity constraint. Our scheme is lightweight, distributed, scalable and adaptable. Using simulation tests, we demonstrate the scalability and performance gain of our scheme over its counterparts with respect to access latency, network load and server load.