Access Point Selection Strategy in IEEE802.11e WLAN Networks toward Load Balancing

摘要

IEEE802.11 WLAN (Wireless LAN) has been widely used in enterprises and public spaces such as airports. In these large WLAN networks, RRM (Radio Resource Management) is necessary for efficient use of radio resources, and also load balancing among APs (Access Point) has to be taken into account. Since, in IEEE802.11, STA (Station) has the right to select an AP with which it will associate, the AP selection mechanism implemented in STA is important for load balancing. This paper proposes an association mechanism called HRFA (High-Rate First Association) in order to achieve load balancing and efficient use of radio resources. Furthermore, IEEE802.11e was developed by Task Group E of the IEEE802.11 working group and specified a MAC protocol to provide QoS in the MAC layer and to support real-time traffic over WLAN. In order for WLAN to be more widely used, the functionalities of IEEE802.11e must be provided in WLAN devices. Our proposed HRFA can be applied to WLANs compliant with IEEE802.11e. Since the HRFA can be implemented without any modifications in the IEEE802.11 and IEEE802.11e standards, it is useful from the implementation-cost and compatibility point of views. Simulation results show that HRFA can efficiently utilize radio resources and can also achieve load balancing in IEEE802.11e WLAN networks.