Robust Streaming Erasure Codes based on Deterministic Channel Approximations

TL;DR

This paper develops near optimal streaming erasure codes for real-time communication over channels with burst and isolated losses, balancing error correction capabilities within fixed delay constraints.

Contribution

It introduces a layered code design that achieves near optimal tradeoffs between burst and isolated erasures for specific channel models, improving upon baseline codes.

Findings

Codes perform well over Gilbert-Elliott channel simulations.

Tradeoff between burst length and isolated erasures is characterized.

Layered design enhances error correction in real-time streaming.

Abstract

We study near optimal error correction codes for real-time communication. In our setup the encoder must operate on an incoming source stream in a sequential manner, and the decoder must reconstruct each source packet within a fixed playback deadline of $T$ packets. The underlying channel is a packet erasure channel that can introduce both burst and isolated losses. We first consider a class of channels that in any window of length ${T+1}$ introduce either a single erasure burst of a given maximum length $B,$ or a certain maximum number $N$ of isolated erasures. We demonstrate that for a fixed rate and delay, there exists a tradeoff between the achievable values of $B$ and $N,$ and propose a family of codes that is near optimal with respect to this tradeoff. We also consider another class of channels that introduce both a burst {\em and} an isolated loss in each window of interest and develop the associated streaming codes. All our constructions are based on a layered design and provide significant improvements over baseline codes in simulations over the Gilbert-Elliott channel.