摘要
目前IEEE802.11a/b/g等无线局域网的物理层均支持多速率的数据传输。无线信号在传输过程中受节点运动、时变干扰、信号衰落等因素的影响较大,因此发送节点采取何种策略预测信道状况和调整数据速率,对提高网络吞吐量有着重要影响。根据发送节点是利用历史信息预测速率还是用RTS/CTS反馈信息确定速率,可以将速率调整分为开环方式和闭环方式。综述了现有绝大部分速率调整机制的性能和特点,对起始速率设置、丢包区分和调整策略等关键问题进行了分析和对比,提出了目前存在的问题和今后主要的研究方向。
In IEEE 802.11/a/b/g Wireless Local Area Networks,the physical layers support multiple transmission rates.Since the wireless channel varies over time due to such factors as station mobility,time-varying interference,signal fading,and so on,it is very important for the transmitting station to assess channel conditions and accordingly adjust the rate in order to yield higher throughout.Rate adjustment mechanism can be classified into open-loop schemes based on statistics information and close-loop schemes based on the RTS/CTS information feedback.We summaried the perfor-mance of the rate adjustment schemes,analyzed the key issues which include initial rate,packet loss distinction and adjustment strategies,and pointed out the present problems and future research interests.
出处
《计算机科学》
CSCD
北大核心
2011年第4期43-47,83,共6页
Computer Science
基金
国家自然科学基金项目(60673164)
新世纪优秀人才支持计划(NCET-05-0683)
湖南省杰出青年基金(06JJ10009)
高等学校博士学科点专项科研基金(20060533057)资助
关键词
无线网络
多速率
数据速率
丢包识别
信噪比
Wireless networks
Multiple rates
Data rate
Loss differentiation
SNR
