Ab.~tract-In interactive voice applications, FEC schemes are necessary for the recovery from packet losses. These schemes need to he simple with a light coding and decoding overhead in order to not impact the interactivity. The objective of this paper is to study a well known simple FEC scheme that has been proposed and implemented [1], [2], in which for every packet n, some redundaut information is added in some subsequent packet n + @. If packet n is lost, it will be reconstructed in case packet n + @ is well received. The quality of the reconstructed copy of packet n will depend on the amount of information on packet n we add to packet n + @ We propose a detailed queueing analysis based on a ballot theorem and obtain simple expressions for the audio quality as a fnnction of the amount of redundancy and its relative position to the original information. The analysis shows that this FEC scheme does not scale well and that the quality will finish by deteriorating for any amount of FEC and for any offset~.
Altman et al. REF study simple media-specific FEC for audio transmission and show that it provides little improvement to the quality of audio under any amount of FEC.
Queueing analysis of simple FEC schemes for IP telephony
Proceedings IEEE INFOCOM 2001. Conference on Computer Communications. Twentieth Annual Joint Conference of the IEEE Computer and Communications Society (Cat. No.01CH37213)
Proceedings IEEE INFOCOM 2001. Conference on Computer Communications. Twentieth Annual Joint Conference of the IEEE Computer and Communications Society (Cat. No.01CH37213)
Computer Science