有效提高无线局域网信道可用带宽的MAC机制  

Effective MAC scheme for improving usable throughput in WLAN

作　　者：冯辉[1] 王挺[1] 胡波[1] 

机构地区：[1]复旦大学电子工程系,上海200433

出　　处：《通信学报》2006年第7期94-99,105,共7页Journal on Communications

摘　　要：802.11WLAN基础架构BSS(基础服务集)的DCF模式下,有两个因素严重影响可用带宽。一是随着竞争站点数增加,信道竞争开销增大,利用率下降;二是AP(接入点)在竞争信道中并无优势,上下行带宽严重不对称,降低了实际利用率。针对这两个问题提出一种新的MAC机制,首先通过在AP端统计MAC地址来估计竞争站点数,然后根据数学模型计算AP和站点上下行比例控制下的最优初始竞争窗值,通过广播设置以获取信道最大利用率。In DCF mode of 802.11 infrastructure BSS, the usable throughput was compromiseel by two main factors. One was the channel utilization ratio decreases when the number of competing stations increases. The other one was the severe asymmetry between downlink and uplink data because AP possesses no advantage position when accessing the share channel. Both problems were solved by a new MAC scheme which adjusts the minimum contention window of AP and station to optimized values derived from a mathematical model under downlink/uplink bandwidth control. Meanwhile, a new estimation method for station number is proposed via dynamic MAC addresses statistic at AP side.

关 键 词：无线局域网 上下行带宽控制 自适应优化 站点估计 

分 类 号：TP393.1[自动化与计算机技术—计算机应用技术]