Wireless Access Point Voice Capacity Analysis and Enhancement Based on Clients' Spatial Distribution

An efficient voice-over-IP (VoIP) support at the wireless access point (AP) of a wireless LAN (WLAN) remains a challenge for the last-mile wireless coverage of IP networks with mobility support. Due to the limited bandwidth that is available in WLANs, an accurate analysis of the voice capacity in such networks is crucial for the efficient utilization of their resources. The available analytical models only provide the upper and lower bounds on voice capacity, which may significantly overestimate or underestimate the WLAN's capability of supporting VoIP and, thus, are not suitable for the mentioned purpose. In this paper, we focus on the voice capacity analysis of a wireless 802.11(a/b) AP running the distributed coordination function (DCF). In particular, we show that by incorporating the clients' spatial distribution into the analysis, we are able to develop a new analytical model for a much more accurate estimation of the average voice capacity. By properly exploring this spatial information, we further propose a new scheme for AP placement such that the overall voice capacity can be enhanced. The efficiency of the new voice capacity model and the new AP placement scheme is validated through both analytical and simulation studies.