MoQ Study: Standard ABR Boosts Throughput for Time-Shifted Streams

A new paper from researchers Abanisenioluwa Orojo, Tanvir Redoy, Samira Afzal, and Andrew C. Freeman evaluates the performance of Adaptive Bitrate (ABR) switching for time-shifted clients in Media over QUIC (MoQ). The in-progress SWITCH specification for MoQ Transport aims to streamline rate adaptation by reducing buffering and playback gaps during network congestion. The team used a Mininet simulated topology to test both live and time-shifted clients under standard ABR algorithms. Their key finding: standard ABR algorithms can be directly applied to time-shifted playback without any modification, leading to substantially higher overall throughput.

Surprisingly, the experiments showed that subscribers can even experience increased throughput after a rebuffering event—a counterintuitive but promising result. The authors attribute this to the behavior of time-shifted buffers absorbing short-term rate drops. While the SWITCH specification is still evolving, this study validates that existing ABR logic can be reused for MoQ with minimal overhead. The paper also identifies focal points for further optimization, such as smoothing out rate transitions for delayed viewers. For streaming engineers, this means time-shifted (catch-up or DVR) content could soon benefit from the same low-latency, high-quality streaming already possible with live MoQ.