Speech quality improvement in ATM networks using an alternating-cell discarding strategy

The inherent redundancy of PCM-coded speech signals allows for some loss of information without severe quality degradation. Thus in asynchronous transfer mode (ATM) networks, some speech cells may be intentionally discarded at the network nodes as a means of controlling temporary congestion. The influence of missing cell patterns on reconstructed speech quality for different cell lengths is examined and a procedure for priority discarding is presented which discards cells of a given speech source in an alternating manner in order to control missing segment statistics for different cell lengths. Such a procedure improves the tolerance of reconstructed speech to missing cells with negligible increase in the complexity of speech processing.