Voice performance in WLAN networks - an experimental study

In this work, we measure Wireless Local Area Network (WLAN) voice performance and capacity. While most WLAN applications today are data centric, the growing popularity of Voice over IP (VoIP) applications and the trend towards convergence with cellular networks will catalyze increased voice traffic. Since voice applications compete not only with each other, but also with data applications for WLAN bandwidth, quantifying voice performance and capacity in the presence of simultaneous data traffic is an important issue. We offer a practical investigation of the 802.11b MAC layer’s ability to support simultaneous voice and data applications. We quantify VoIP capacity for standard WLAN networks, indicative of those already in the field, as well as evaluate the practical benefits of implementing backoff control and priority queuing at the access point. Conclusions are drawn based on an extensive set of real-world measurements conducted using off-theshelf equipment in an experimental testbed.