Proxy caching in wireless mesh networks

Nowadays, a wireless mesh network can be inexpensively deployed to provide the Internet access. One key challenge in the deployment is how to maintain high transfer throughput. As the network size grows, the transfer throughput falls rapidly due to MAC interference. Caching has been proposed in previous works to solve this problem. The common caching technique is on-path caching, whereby the caching function on each mesh router is enabled to cache data during data transfer. However, a cache request is only forwarded to a single upstream node specified in the routing table as the next hop to the gateway, leading to congestion. In this research, we propose the random-path cache request technique, whereby a cache request can be forwarded to any neighboring upstream node toward the gateway besides the one specified in a routing table. This approach distributes the network load across several network paths, leading to lower transfer delay. Our simulation study shows that random-path cache request provides consistently better average transfer delays than single-path cache request, with the degree of improvement depending on the network topology. The results also suggest that both cache request techniques operate well if the file request rate is sufficiently high.