Load Distribution In

A key issue in Wireless LANs (WLANs) is the management of user congestion at popular zones called “hot-spots”. At these sites, there are several access points (APs) with overlapped coverage and throughput is usually unevenly distributed among them. The reason is that the current IEEE 802.11 standard does not support a mechanism to distribute stations, thus they select APs based exclusively on the received signal quality. In addition, when the number of users per AP increases, the throughput per user decreases. As a result, the total network throughput is reduced producing under utilisation of the network resources. Several approaches have been suggested to solve this problem. Some of them are based on the modification or enhancement of the MAC layer, hence changes to the physical layer are required. This would imply that all deployed stations should be changed. Other approaches are based on adding Quality of Service (QoS) support to the standard. These solutions require that stations and APs cooperate, which makes its deployment difficult in existing WLANs. Recently, some vendors of WLAN devices have incorporated load-balancing capabilities within their products. Nevertheless, they also require cooperation betwee