Link-Quality Aware Object Replication and Placement for Multi-hop Wireless Mesh Networks

Wireless mesh networks (WMNs) were proposed to provide low-cost, easy deployment and robust access to the Internet. One of the objectives in WMNs is the improvement of client throughput, which can be achieved using content replication. Many replication schemes are specifically designed for the Internet. However, they do not account for the different characteristics of wireless networks, such as insufficient and fluctuating bandwidth, packet loss, contention to access the wireless medium, etc. In this paper, we study the problem of object replication and placement in WMNs, where mesh nodes act as replica servers in a P2P model that improves Quality of Experience by replicating content as close as possible to the requesting mesh clients. Furthermore, we aim to optimize the number of replicas per object to better utilize the storage capacity per node. In WMNs, the wireless link-quality is paramount in the placement decision and the measurement of the object access cost. Therefore, we propose a link-quality aware, distributed and scalable scheme for object replication. The proposed scheme exploits the long-term link-quality routing metrics to augment the replica placement decision and the instantaneous link-quality metrics for replica server selection. The simulation results show that our proposed scheme has better performance compared to other replication schemes.