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

Abstract

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.Index Terms-Application layer forward error correction (AL-FEC), burst and isolated errors, Gilbert-Elliott channels, low-delay codes, real-time streaming communication.

Capacity of Burst Noise-Erasure Channels With and Without Feedback and Input Cost

“…Theorem 1: The capacity of an NEC without feedback is given by 2 These conditions are similar to the ones considered in [20]. 3 These properties will not be needed in Section V. March 2, 2018 DRAFT where ε = P Z i (e) is the probability of an erasure,H(·) denotes the entropy rate andZ…”

“…Throughout the paper, it is assumed that the NEC satisfies properties S-I and S-II above. 3 We next present our first main result.…”

“…When {Z i } ∞ i=1 is stationary memoryless (i.e., independent and identically distributed) and q = 2, the channel reduces to the BEC. The above burst EC also includes the Gilbert-Elliott erasure model (e.g., [1]- [3]) as a special instance.…”

On the Equivalence Between Maximum Likelihood and Minimum Distance Decoding for Binary Contagion and Queue-Based Channels with Memory

“…Also, digital storage devices where errors occur in clusters can be well approximated by these models; indeed the IMCC and FMCC were originally studied in light of the observation that failures in semi-conductor chips are better characterized by a Polya "contagion" distribution [8]. Furthermore, the noise processes of the FMCC and QBC are viable alternatives (in light of their explicit Markovian structure and low number of parameters) to the typically used GilbertElliott channel (GEC) [13] error process and other hidden Markov processes (e.g., see [14]) for capturing the packet loss behavior in data networks, since in practical networks, packet losses are often time-dependent due to a variety of causes including congestion and buffer overflow. The contributions of this work include the following.…”

Priority-Based Real-Time Stream Coding under Burst Erasures

“…Another coding scheme presented by Martinian and Badr in [5] [6] can adjust the delay deadline according to the channel quality. Prominent works also have been done in [7] [8], where low delay streaming coding schemes over burst and isolated erasures were studied. However, all these works only deal with real-time streams with uniform messages, and haven't considered the difference of these messages.…”