Researches Of Intelligent Frequency Optimization On Wireless Local Area Network

With the mature and broad usage of wireless local area network, the contradiction between the limited frequency resources and great amount of access points will necessarily lead to the interference between the access points. This interference will result in the decrease of the available communication capability of the whole system.Most of the present network optimization technologies rely on manual measurement and optimization, so they are not suitable for the cheap, flexible, highly compatible wireless local network. Through the analysis of the characteristics for the wireless local network, the author put forward a new intelligent frequency optimization technology for the frequency optimization of the wireless local network. This intelligent frequency optimization technology follows the criterion of minimum interference of each individual access point, which is based on the measured information of AP. The distributed optimization structure of this technology enables each AP select the best operating frequency. Besides, it makes each AP waits for a random period of time before the AP changes its operating frequency, thus avoids the ping-pong phenomenon during the optimization process.The criterion of minimum total interference and the criterion of minimum individual interference are the two criterions that can be adopted in the intelligent frequency optimization process. The criterion of minimum total interference in essence is to obtain the frequency distribution scheme that makes the target function of total interference gets the minimum, while the criterion of minimum individual interference is to obtain the extremum. The latter criterion is the necessary condition for the former criterion. This opinion is validated by the simulation test based on the network conditions for IEEE802.11b.There are two kinds of realization structures, centered structure and distributed structure, for the intelligent frequency optimization scheme. It is found by simulation test that both structures can avoid the ping-pong phenomenon during the optimization process. It is also found that, compared with the centered structure, the distributed structure can convergence with higher speed, obtain better compatibility and can be realized more easily.