Paper publication: Cross that boundary - Investigating the feasibility of cross-layer information sharing for enhancing ABR decision logic over QUIC
In the HTTP Adaptive Streaming (HAS) paradigm, client-side Adaptive Bitrate (ABR) algorithms drive the (quality-variant) scheduling and downloading of media segments. These ABR algorithms are implemented in the application layer and can therefore base their logic only on relatively coarse and/or inaccurate application-layer metrics. The recently standardized QUIC transport protocol has many userspace implementations, which paves the way for cross-layer optimizations by exposing transport-layer metrics to application-layer algorithms. In this paper, we investigate whether the availability of fine-grained transport-level throughput metrics can positively impact the operation of ABR algorithms and hence the Quality of Experience (QoE) of HAS users. Our results show that QUIC-level throughput data can indeed aid ABR algorithms to more accurately predict playout buffer underruns, which in turn allows the ABR algorithm to take reactive measures in a timely fashion such that playback stalls can be avoided under challenging network conditions.