Universal Codes For Minimizing Per-User Delay on Streaming Broadcast Channels

We study the fundamental limits of decoding delay in providing reliable communication for real-time applications. After presenting a simple example to illustrate the difficulties in using traditional block codes, we propose a new communication model to study decoding delay for streaming broadcast channels. We prove a coding theorem establishing that, for certain collections of channel ensembles, delay-universal codes exist which simultaneously achieve the best delay for any channel in the collection. Such codes can reduce the latency in video conferencing, tele-medicine, remote monitoring, control, and related scenarios.