Adaptive Service Differentiation Over 802.11e MAC Protocol

摘要

In this paper, we consider the various (QoS) aspects of the (WLAN) standard IEEE 802.11- 2007 and its MAC protocol. This involved focusing on the work to enhance the Distributed Coordination Function (DCF) access mechanism of IEEE 802.11e, denoted as Enhanced Distributed Channel Access (EDCA). Efforts to improve on EDCA by changing the Contention Window (CW) adaptively were also reviewed. In this study, a new hybrid adaptive technique, denoted as (CWpro), is proposed. The performance of this scheme was tested and validated using NS2 simulation software. Results showed that CWpro offers improved performance over EDCA and other adaptive schemes, for both audio and video as prioritized categories with respect to delay, goodput, channel utilization and collision rate.