The Effect of Block-wise Feedback on the Throughput-Delay Trade-off in Streaming

TL;DR

This paper investigates how block-wise feedback frequency influences the trade-off between throughput and in-order delay in streaming, proposing coding schemes to optimize performance based on application needs.

Contribution

It analyzes the impact of feedback delay on throughput-delay trade-offs and introduces a spectrum of coding schemes for different operating points.

Findings

Immediate feedback achieves optimal throughput and delay

Increased feedback delay forces trade-offs between throughput and delay

Different coding schemes can be chosen based on application sensitivity

Abstract

Unlike traditional file transfer where only total delay matters, streaming applications impose delay constraints on each packet and require them to be in order. To achieve fast in-order packet decoding, we have to compromise on the throughput. We study this trade-off between throughput and in-order decoding delay, and in particular how it is affected by the frequency of block-wise feedback to the source. When there is immediate feedback, we can achieve the optimal throughput and delay simultaneously. But as the feedback delay increases, we have to compromise on at least one of these metrics. We present a spectrum of coding schemes that span different points on the throughput-delay trade-off. Depending upon the delay-sensitivity and bandwidth limitations of the application, one can choose an appropriate operating point on this trade-off.