南京大学学报：自然科学版2011，Vol.47Issue(5)：585-593,9.
一种基于区分服务的IEEE 802.11 QoS信道访问控制机制
A QoS-aware 802.11 media access control mechanism based on differentiated services
摘要
Abstract
Research shows that the main characteristics of wireless mobile ad hoc networks include finite bandwidth,unstable channel quality,and the change of network topology caused by node mobility.These characteristics degrade the network performance significantly and especially identify challenges for providing QoS guarantees for real-time multimedia applications over wireless mobile ad hoc networks（MANETs）.This paper proposes a QoS-aware MAC mechanism based on Differentiated Services for MANETs,which mainly supports real-time data flow transfer.This mechanism makes an improvement based on traditional IEEE 802.11 DCF mechanism.The main idea is introducing new types of service-denied frames named NTS,which makes destination nodes refuse low-priority data with probability p,according to dynamic channel conditions.Probability p is designed for a monotonic function increasing with number of frame retransmission attempt.As the number of retransmission attempt increases,it indicates that the competition in channel is getting more fierce,which makes it more necessary for protecting high-priority frames,by means of refusing low-priority data with higher probability.We study the behavior of several nodes with a Markov model.Using the model,we evaluate the saturation throughput,packet drop probability,as well as time delay performance.Our mathematical analyses demonstrate that the proposed mechanism improves the performance of real-time data flow with a high-priority significantly,in terms of achieved bandwidth,end-to-end delay and frame dropping probability.关键词
无线自组织网络/多媒体服务质量/区分服务/媒体接入控制Key words
ad hoc networks/multimedia QoS/diffserv/medium access control分类
信息技术与安全科学引用本文复制引用
曹磊,白光伟,吴志刚,吴艳洁..一种基于区分服务的IEEE 802.11 QoS信道访问控制机制[J].南京大学学报：自然科学版,2011,47(5):585-593,9.基金项目
国家自然科学基金 （）
江苏省自然科学基金 （）
教育部留学回国人员科研启动基金 （）
江苏省＂青蓝工程＂中青年学术带头人培养对象 （）
江苏省省属高校自然科学基金 （）
南京工业大学青年学科基金 （）
