Improving QoS Performance of EDCA in IEEE 802.11e Wireless Networks

• Main Authors: Hung, Li-Wei, 洪立韋
• Other Authors: Tsai, Tzu-Chieh
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/91944977963893917337

碩士 === 國立政治大學 === 資訊科學學系 === 94 === Wireless LANs (WLANs) based on the IEEE 802.11 family have recently become popular for allowing high data rates at relatively low cost. However, due to the limitation of 802.11 DCF, they are not suitable for real-time service and do not support service differentiation. To expand providing applications with quality of service (QoS) requirements in WLANs, the IEEE 802.11E Task Group was formed to enhance the current 802.11 medium access control (MAC) protocol. In real networks, the network condition is dynamic. The 802.11e cannot reach high performance of QoS. Besides, design of efficient MAC protocols with both high-throughput and low-jitter performance is the major focus in distributed contention-based MAC protocol research. In view of this, we propose a new and applicable approach, called Dynamic-EDCA (D-EDCA), adjusts the parameters of system based on the network condition. The result of　simulation shows that in comparison with EDCA, our proposed algorithm improves total throughput more than 45%, and the maximum of connection more than 40%. It also reduces voice delay about 80%, and video delay about 25%. Thus, the proposed D-EDCA utilizes bandwidth more efficiently and improves performance for service differentiation.