Analytical investigation of the performance of packet-level FEC techniques in VoIP communications
Leopoldo Estrada, Deni Torres-Román, Homero Toral · 2009
In this work, the distributions of the number of received and lost packets, respectively named gap and burst, of a VoIP communication are modeled with discrete finite-state Markov chains. Through a study of measurements from monitored VoIP calls, it is shown that these models can adequately represent the geometric-type decay of these distributions. Two-state model performs well for homogeneous losses but for nonhomogeneous losses four-state model fits better. An analysis of the performance of a packet-level FEC scheme, based on n-packet redundancy, is developed. The perceived packet loss rate that results of applying this correction scheme is quantified. The studied measurements show that 1-packet redundancy is generally sufficient to improve the quality of the communication to an acceptable level.