A Load-balancing Framework for Cognitive Wireless Network to Coexist with Legacy WiFi Systems

This paper proposes a framework to collect bandwidth information from terminals, analyze them statistically, and feed back to terminals in order to increase usable bandwidth in terminals keeping coexistence with legacy WiFi systems. This coexistence feature enables practical integration of the proposed framework with the legacy WiFi systems including Internet. By introducing two-level transmission via components categorized into radio access network side and core network side, replacement or modification on existing systems is not required for deployment of the proposed framework. The feedback is transmitted using multicast from APs to terminals in order to reduce message traffic, but the transmission from the server to APs is unicast because the current Internet does not fully support the IP multicasting. The proposed algorithm increases minimum throughput among all terminals by more than twice at maximum per terminal as well as total network throughput by 30% on average, compared with random selection method.