Perceptual Quality of Internet Telephony over IEEE 802.11e Supporting Enhanced DCF and Contention Free Bursting

As the IEEE 802.11 based internet access is becoming ubiquitos available it is excepted that WLAN will be applied for telephony. In this paper we follow the objective to access whether WLAN allows calls at toll quality. Toll quality is the minimal quality of PSTN-based telephons calls. With simulations we evaluate the MAC protocol modes distribution coordination function (DCF), enhanced DCF (EDCF) and contention free bursting (CFB). We have verifed our simulation model by cross-checking it with the results of other researchers. We present quantitative results of the perceptual quality and enhance the precision of performance evaluation on Voice over Wifi systems.