QoS-based optimal adaptive playout-buffer scheduling using the packet arrival distribution

Abstract

A voice conversation quality over IP networks is mainly affected by the end-to-end delay and the packet-loss rate. Various delay channel environment can cause the early/late arrival packet loss without actual packet loss. To overcome time-variant dynamics of transmission channels for IP telephone services, an adaptive playout-buffer scheduling is proposed. Previous playout-buffer schedulers focused on eliminating delay variation effects regardless of the quality of service (QoS). The proposed metric provides a minimum playout-buffer size, simultaneously meeting a desired QoS. The minimum buffer size is desirable because of the impact of the end-to-end delay on the perceived speech quality. The optimal buffer size is analytically calculated by exploiting the stochastic distribution of the packet arrival intervals.