ANSI/IEEE Std 802.11, 1999 Edition 802.11 standard is a standard instituted by the Wireless Local Area Network Standard Working Group for physical layer protocol and medium access control (MAC) protocol, which facilitates the establishment of the interoperating network equipment by the wireless local area network devices manufacturers and wireless devices manufacturers. Physical layer defines the signal feature and signal modulation of data transfer. The medium access control (MAC) layer can be deemed as being composed of a series of services which can accomplish the functions such as information exchange, power control, association management, synchronal management and process management.
WLAN (wireless local area network) means interconnecting computer devices by using wireless communication technology, so as to configure a network system capable of communicating with each other and implementing a resource sharing. In a WLAN network environment, an extended service set system is composed of one or a plurality of base service sets and a distribution system in the connection with the above, each of which at least comprises one wireless access point apparatus. The extended services sets are distinguished by ESSID (Extended Services Sets Identifier) and the wireless access points are distinguished by BSSID (Basic Services Sets Identifier). A station obtains the information of the Extended Services Sets and Basic Services Sets in the present WLAN environment by scanning channels and selects to join an appropriate basic services set. Load balance in WLAN is a strategy, under which a wireless local area network system comprises a plurality of access points providing access services to a variety of mobile stations, wherein each of the access point members allows or rejects the access of a mobile station by station management using network information, thereby balancing the network load, taking full advantage of the available network resource and reducing the network congestion. Usually the distribution of access points joining the load balancing should meet the conditions that a station can selectively get access to another access point with lower load, when the access point rejects the access of the station owing to overload; access points meeting the above-mentioned conditions are divided in a group called load group, the station must selectively get access to an access point in the load group, the access point having relative lower load and relative most appropriate for the access of the station.
The current wireless local area network protocol has not stipulated how the load balance processing is conducted and how the load balance information is exchanged in the network. The regular implementing method is collecting and managing the network load balance information under the information exchange protocol between the access points, wherein the load balance information brings a great deal of additional overhead when it is being broadcasted in the network; moreover, the unicity of the load balance information renders a low quality of the station access, which makes against the optimized management to the whole network. In regard to a WLAN network conducting access and resource optimization, it is advantageous for the improvement of the quality of the network communication to implement an optimized load balancing system with high performance.