Network Delivery Time Control: a Novel Approach to Rate Adaptation for Low-Latency Video Flows

This paper presents Network Delivery Time Control (NDTC), a new approach to rate-adaptive, low-latency media streaming for interactive services and currently used by Netflix’s cloud gaming service. At its core is our novel Frame Dithering Available Capacity Estimation (FDACE) heuristic. FDACE dithers frame emission periods of an application’s existing traffic and non-destructively estimates available path capacity from the distribution of frame reception periods over time. Unlike strategies that actively probe for excess capacity, FDACE avoids inducing symptoms of congestion such as increasing network latency or packet losses. Using FDACE-reported path conditions, NDTC dynamically adapts frame emission times, and frame sizes, for timely frame delivery. NDTC incorporates response to traditional congestion signals as a backstop against extreme real-world network conditions. We show that NDTC combines effective capacity estimation, on-time low-latency frame delivery, low self-induced loss rates, and fast response to abrupt network changes.