A Two-level Cross-talked Admission Control Mechanism for QoS Guarantee in 802.11e EDCA

LANGUAGE
English
SOURCE
Tsinghua Science & Technology, Vol.13, Issue 6, December 2008
Published Date:2008-12-01
ABSTRACT
In this paper, a two-level cross-talked admission control mechanism is proposed to guarantee QoS (Quality of Service) requirements for multimedia applications over WLANs (Wireless Local Area Network). Firstly, an EDCA (Enhanced Distributed Channel Access) analytic model is used to compute the maximum number of admitted users according to the QoS requirements and the packet arrival characters. Then, some channel resource is reserved for handoff calls according to the maximum number of admitted users and the call level traffic model. The channel utilization ratio is also measured to denote the current system traffic load. The maximum number of admitted users and channel utilization ratio are used for admission control for applications with QoS requirements in call level, while they are also used for rate control of best effort applications in packet level by using the p-NACK scheme. Thus, QoS requirements is statistically guaranteed while the system is efficiently utilized. Simulation results validate the efficiency of our mechanism in QoS guarantee and bandwidth utilization.
KEYWORDS
WLAN, EDCA, QoS, admission control, rate control