Impact of Sub-Segment Representations in DASH on the Live Streaming Experience

The demand for low-latency live streaming continues to grow, necessitating advancements in transport and packaging technologies. Media-over-QUIC (MoQ) has emerged as a promising approach for scalable, low-latency streaming, though its adoption remains in early stages. Meanwhile, the 6th Edition of MPEG-DASH introduces Sub-Segment Representations (SSR) to reduce tune-in times by leveraging dual-encoding strategies with varying Group of Pictures (GOP) lengths. This paper evaluates the feasibility of SSR in ultra-low latency streaming environments, particularly its interaction with Content Delivery Networks (CDNs) and HTTP/3 stream prioritization. Through controlled experiments, we compare the performance of Low-Latency Low-Delay (L3D) playback against standard playback under different CDN configurations. Results indicate that L3D significantly reduces preroll buffering and stabilizes playback, even at sub-second latencies. Additionally, our findings highlight the role of QUIC and HTTP/3 in optimizing live streaming performance. These insights contribute to understanding SSR's potential in improving scalability, latency, and viewer experience in live streaming workflows.