Performance evaluation of EVRC-encoded voice traffic over CDMA EVDO Rev. A

Voice traffic is not efficiently supported by CDMA EVDO Rev. A from its original design, but an efficient approach is needed to support voice traffic over CDMA EVDO Rev. A for graceful migration from CDMA2000 1x to CDMA EVDO Rev. A as voice service revenue is still the dominant income source for cellular service providers. To understand the system design tradeoffs, we first investigate the traffic characteristics of EVRC-encoded real voice traces and we find that the correlation structure of voice traffic exhibits strong long-range dependence. We further observe that the burst length distribution of voice traffic is heavy-tailed. Traditional Markov-model could not accurately characterize the true nature of the voice traffic. In the major part of our study, we examine the tradeoff between the initial play out delay and voice quality for real voice traces over CDMA EVDO Rev. A. We also examine the tradeoff between voice quality and RF conditions, e.g., the location of mobiles and the number of mobiles in a sector, etc. Finally, we address the performance aspects of voice traffic over CDMA EVDO Rev. A with adaptive frame bundling (AFB) techniques.