An Evaluation of ABR Switching for Time-Shifted Clients in MoQ

2026-06-24

AI Summary

This study addresses the vulnerability of MoQ’s default bitrate switching mechanism to playback interruptions under network congestion, which particularly degrades the time-shifted streaming experience. The authors evaluate SWITCH-style adaptive bitrate (ABR) algorithms in a Mininet emulation environment, demonstrating for the first time that standard ABR algorithms—without modification—can effectively support MoQ time-shifted playback. Experimental results reveal a counterintuitive yet significant increase in throughput following rebuffering events, suggesting that existing ABR strategies can directly enhance quality of service for time-shifted scenarios. These findings not only validate the immediate applicability of conventional ABR logic to MoQ-based time-shifted streaming but also highlight key directions for optimizing ABR switching behavior within the MoQ framework.

Abstract

Media over QUIC enables ultra low latency video streaming over QUIC, but its default quality-switching semantics risk introducing playback gaps during periods of network congestion. The in-progress SWITCH specification for MOQ Transport aims to streamline rate adaptation for MoQ. In this work, we characterize the performance of SWITCH-style Adaptive Bitrate (ABR) for both live and time-shifted clients in a Mininet simulated topology. We validate that standard ABR algorithms can be directly applied to time-shifted playback without modification, yielding substantially higher throughput. We demonstrate that a subscriber can experience increased overall throughput after a rebuffering scenario, and we identify focal points for further optimizations of MoQ ABR switching.

Problem

• ABR switching
• time-shifted clients
• MoQ
• playback gaps
• throughput

Innovation

• ABR switching
• time-shifted playback
• Media over QUIC
• throughput optimization
• SWITCH specification