New technique for improving voice quality degraded by cell loss in ATM networks

The voice over ATM´s phenomenal growth, worldwide coverage and increasing data delivery capabilities have made possible its use as an alternative communications medium for voice messages. In addition, using the voice over ATM communication circumvents the high costs of long-distance phone rates. However, this technique is a relatively harsh environment for real-time voice communication. Cells transmitted over the ATM network are subjected to late deliveries and losses. This paper discusses the various voice packet cells recovery techniques to enhance voice delivery for voice over ATM communication. These include both receiver and source techniques. Further, a new technique for cell loss recovery incorporates both embedded coding as well as trinary waveforms and encoding. For any given sample, the proposed methods recovered over 95% of the ATM cell loss, and, hence displeasing noises in the recovered voice signal. As a result, the SNR has been improved by a percentage value of 35% compared to the previous works