Burst erasure correction codes with low decoding delay

We present a new class of systematic, time-invariant, convolutional encoders suitable for low delay burst erasure correction. Specifically, we show that the new encoders have the shortest possible decoding delay required to correct all bursts of a given length with a fixed redundancy. By comparing the new encoders to maximum distance separable (MDS) codes, we show that the latter generally require either more redundancy or more delay to correct bursts of a given length. In addition, we show that the new encoders can achieve better performance than MDS codes on a simple two-state Markov erasure channel. Thus, we demonstrate the advantages of using cross packet coding for delay-sensitive applications such as Voice over Internet Protocol, video-conferencing, etc., on bursty packet networks. Finally, we discuss suitable performance measures for encoders designed to correct both burst and random erasures and report the results of a computer search for such hybrid encoders.