QoS enhancement for VoIP using a new FEC scheme with backup channel

This paper proposes a new FEC scheme using backup channel to send redundant information instead of piggybacking the main packet. This is particularly applicable to the modem IP networks which are distributed all over the world. In this method only one source coder for both the main and the redundant payload is used to reduce the overall computational complexity. The Gilbert loss model (GLM) is employed to verify the improvement of the packet loss probability in this new method compared with that in a single path FEC scheme. It is shown, through simulation results that using our proposed backup channel can considerably improve the packet loss and delay performance of the VoIP networks.