VoIP Capacity over PCF with Imperfect Channel

Voice, in the form of VoIP, has emerged as a dominating traffic category in the Internet. VoIP traffic suffers from severe voice quality degradation if the end-to-end delay and loss becomes high. PCF medium access mechanism offers delay bound delivery which is a crucial attribute for delay sensitive applications like VoIP. But due to its unavailability in most commercial products, little analysis has been done on PCF for supporting VoIP traffic. Most importantly, standard voice quality assessment methods are not used in the capacity studies. We propose a VoIP capacity model for PCF that uses voice quality as the limiting factor and takes imperfect channel condition into account. The effects of aggregation level, packet error rate and voice quality on VoIP capacity are investigated, and a comparison between voice capacities under PCF and DCF is presented. The proposed model will be extremely useful in designing networks to support quality voice calls.