摘要
为了在802.11的网络中提供服务质量(QoS)支持,IEEE 802.11 Task Group E提出了EDCF协议.然而EDCF只能提供业务区分服务,并不能提供服务质量(QoS)保证.为了能在重负载下提供QoS保证,在WLAN中加入呼叫接纳控制(CAC)机制是非常必要的.本文首先提出了一个新的3维Markov模型对非饱和状态下EDCF的吞吐量和平均接入时延进行了分析.并在此基础上,提出了一种基于效用函数的CAC策略,它可以使网络的总收益达到最大.最后通过大量仿真验证了所提出的CAC策略的有效性.
The draft IEEE 802.11 e standard aims at providing quality of service （QoS） support in 802.11 wireless local area networks （WLANs）. Enhanced distributed coordination function （EDCF）, being the fundamental medium access control mechanism in IEEE 802.lie,can only provide service differentiation but offers no QoS guarantees. While service differentiation does not perform well under high traffic load conditions, call admission control （CAC） becomes necessary in order to provide and support the QoS of existing calls. In this paper, we first establish a new 3-D Markov model to analyze the non-saturation throughput and mean access delay performance of differentiated service provided by EDCF. Based on the new model, we propose a novel CAC strategy in WLANs based on utility function, which can maximize the total income of WLAN. Simulated performance results demonstrate the effectiveness of the proposed CAC algorithm.
出处
《电子学报》
EI
CAS
CSCD
北大核心
2008年第7期1429-1434,共6页
Acta Electronica Sinica
基金
国家自然科学基金(No.60496315,No.60672059,No.60502023,No.60703099)
国家863高技术研究发展计划(No.2006AA01Z233)
