Scalable and robust WLAN connectivity using access point array

With the enormous economies of scale of wireless LAN (WLAN) hardware, the price of commodity WLAN access points has dropped to the level that is even cheaper than some WLAN adapters. In this paper we propose to put together an array of off-the-shelf access points, each operating at a different radio frequency, to build a super access point that can both scale up the overall sustained throughput and improve the robustness of WLAN connectivity in the presence of failures and denial-of-service attacks. The key enabling technology for the proposed access point array architecture is a dynamic load balancing mechanism that can adaptively adjust the association between stations and access points so as to distribute the traffic load among the array´s channels. We have successfully developed such a load balancing mechanism and used it to build a working access point array prototype. Measurements on this prototype show that the proposed load balancing scheme can indeed improve the overall throughput and mitigate performance impacts due to misbehaving stations. In addition, the prototype requires no modification to either the access points or the stations, making it a technology readily applicable to existing wireless LAN environments.