Abstract
As 802.11g devices develop, it is possible for WLANs to support heavy voice communications. In this paper, an improved evaluation model which presents more detail on voice communications is introduced. The best and acceptable speech quality speech quality of 802.11b and 802.11g WLANs are obtained and compared to the theoretical results. The effect of playout algorithms are compared which come to conclusion that the playout algorithms play a more important role as the network condition getting worse.