Packet loss concealment


Packet loss concealment is a technique to mask the effects of packet loss in voice over IP communications. When the voice signal is sent as VoIP packets on an IP network, the packets may travel different routes. A packet therefore might arrive very late, might be corrupted, or simply might not arrive at all. One example case of the last situation could be, when a packet is rejected by a server which has a full buffer and cannot accept any more data. Other cases include network congestion resulting in significant delay. In a VoIP connection, error-control techniques such as automatic repeat request are not feasible and the receiver should be able to cope with packet loss. Packet loss concealment is the inclusion in a design of methodologies for accounting for and compensating for the loss of voice packets.

PLC techniques

PLC is used with the codecs Internet Low Bitrate Codec and SILK in Skype, in Jitsi with the SILK and Opus codecs, and in the pjsip stack used by CSipSimple. Google Duo uses WaveNetEQ, a generative model based on DeepMind/Google AI’s WaveRNN.