无线局域网的一种功率控制算法

A Kind of Power Control Algorithm of WLAN

随着无线局域网(WLAN)的普及率的提高,无线访问接入点(Access Point,AP)的分布密度越来越大。而在IEEE802.11中并没有功率控制的相关内容,为了确保覆盖,往往将AP的发射功率设定为最大值,从而导致不同的AP-无线站点对之间的干扰越来越严重,以及网络整体吞吐量的下降。为了解决问题,提出了针对802.11无线局域网的一种分布式功率控制算法。根据AP自身的实际吞吐量与预期吞吐量之间的关系,判断信道质量,并进行动态调整AP的发射功率。在NS2的环境下仿真结果表明算法简单,收敛速度快,能够确保尽可能多的无线站点获得AP提供的网络接入服务,实现负载均衡;同时尽量减少不同AP-无线站点对之间的相互干扰,提高网络整体吞吐量。

The density of the wireless Access Point is increasing with the increase of the application of WLAN. Power control is not mentioned in the IEEE 802. 11, so the transmit power of the AP is set to its maximum in order to cover larger area, which causes serious interference between different AP to wireless station transmissions and reduction of throughput of the network. In this paper, a kind of distribute power control algorithm is introduced to solve this problem. The AP adjusts its own transmit power according to the relationship between the expected throughput and the actual throughput during a period of time. This paper gives the process of the algorithm and simulates it with NS2. The results of the simulation indicate that the algorithm can improve the total throughput by reducing the RF interference and make sure that the AP can serve as many wireless stations as possible.