Streaming Codes With Partial Recovery Over Channels With Burst and Isolated Erasures

We study forward error correction codes for low-delay, real-time streaming communication over packet erasure channels. Our encoder operates on a stream of source packets in a sequential fashion, and the decoder must output each packet in the source stream within a fixed delay. We consider a class of practical channel models with correlated erasures and introduce new "streaming codes" for efficient error correction over these channels. For our analysis, we propose a simplified class of erasure channels that introduce both burst and isolated erasures within the same decoding window. We demonstrate that the previously proposed streaming codes can lead to significant number of packet losses over such channels. Our proposed constructions involve a layered coding approach, where a burst-erasure code is first constructed, and additional layers of parity-checks are concatenated to recover from the isolated erasure patterns. We also introduce another construction that requires a significantly smaller field-size and decoding complexity, but incurs some performance loss. Numerical simulations over the Gilbert-Elliott and Fritchman channel models indicate that by addressing patterns involving both burst and isolated erasures within the same window, our proposed codes achieve significant gains over previously proposed streaming codes.