A cross layer QoS algorithm to improve wireless link throughput and voice quality over multi-rate WLANs

Abstract

Voice over IP (VoIP) applications over wireless local area networks (WLANs) has become increasingly popular in recent years. VoIP is sensitive to delay and variations in packet interarrival times and require a steady and a dependable stream of packets to provide reasonable voice quality. Therefore, it is important to analyze the performance of the IEEE 802.11 protocol accurately by considering the effects of channel conditions, frame size, number of nodes and collision probability. In this paper, we present an analysis of link layer behavior for ideal and error prone channels by classifying the packet loss caused either by congestion or wireless medium errors and propose an efficient, adaptive, codec and frame size modification algorithm for the optimization of maximum throughput and voice quality on multirate WLANs. Copyright © 2010 ACM. © 2010 Elsevier B.V., All rights reserved.