Embedded MDS codes for multicast streaming

Ahmed Badr, Rafid Mahmood, Ashish Khisti

Abstract: We study low-delay streaming codes for erasure channels in point-to-point and multicast scenarios. We consider a sliding window erasure channel which captures the temporal correlation in packet losses observed in real channels. This correlation is often modelled using statistical channels such as Gilbert-Elliott channel. In the point-to-point case, we provide a new class of codes, Embedded Maximum Distance Separable (EMDS) codes, which recovers from channels introducing a mixture of burst and isolated erasures. Moreover, we propose a technique that extends point-to-point codes for the multicast scenario with two receivers that tolerate different delays, T <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> and T <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> . The multicast codes opportunistically decode packets with short delay T <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1</sup> when the channel is relatively better and with long delay T <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> when the channel is worse. Simulations over multicast Gilbert-Elliott channels show that EMDS codes outperform other streaming codes for both users.