Delay Minimization in Real-time Communications with Joint Buffering and Coding

TL;DR

This paper derives a closed-form expression for minimal delay in real-time communication systems that combine buffering and erasure coding, emphasizing the importance of network parameter knowledge and the trade-off between buffer and coding delays.

Contribution

It provides a novel analytical expression for minimal delay in combined buffering and coding systems, incorporating recent finite block length coding results.

Findings

Accurate network parameter knowledge is crucial for optimal delay performance.

When network delay variance is high, buffer delay becomes negligible.

Optimal delay allocation shifts towards erasure coding in high-variance scenarios.

Abstract

We present a closed-form expression for the minimal delay that is achievable in a setting that combines a buffer and an erasure code, used to mitigate the packet delay variance. The erasure code is modeled according to the recent information-theoretic results on finite block length codes. Evaluations reveal that accurate knowledge of the network parameters is essential for optimal operation. Moreover, it is shown that, when the network packet delay variance is large, the buffer delay becomes negligible. Therefore, in this case the delay budget should be spent mainly on the erasure code.