Cooperative Caching System for High Density Client Environment in TDLS Supported IEEE 802.11 WLAN Networks

Abstract

As the consumer demand for internet connection with mobile device increases, mobile carriers are now actively deploying IEEE 802.11 Wireless Local Area Networks (WLAN) in public places. In this type of WLAN environment, networks naturally suffer from bottlenecks in the APs wireless backhaul and WLAN channel. While the bottleneck in the wireless backhaul can be simply alleviated by using cache in the AP, AP cache cannot mitigate the bottleneck in the WLAN channel because the location of the cache is before the channel. To solve the bottleneck problem caused by traffic overload, I propose the cooperative caching system that uses both AP cache and client caches. TDLS link is used to exchange cached data directly between two clients. By adjusting the internal parameter named offloading probability, the system can adaptively control the workload allocation ratio between AP cache and client caches according to the current traffic load. The simulation results show that the proposed system achieves the performance higher than the AP cache-only system and lower than the client-cache only system. However, the proposed system is more energy-efficient than the client cache-only system according to the aggregated client cache throughput result. In conclusion, the proposed system can achieve energy-efficient caching performance by adaptively adjusting offloading probability.