A Practical Congestion Control Algorithm for Low-Latency Interactive Video Streaming
Shibo Wang, Jianjun Xiao, Xiao Kong, Chenglei Wu, Shusen Yang, Cong Zhao, Chenren Xu, Hong Li Xu, Jing Wang, Honghao Liu · IEEE Transactions on Networking · 2025
Congestion control (CC) plays a pivotal role in low-latency interactive video streaming such as cloud gaming. However, existing end-to-end CC methods often cause self-induced network queuing. As a result, they may largely delay video frame transmission and undermine the user’s quality of experience. In this paper, we present a new, practical CC algorithm namedPudicathat strives to achieve near-zero queuing delay and high link utilization while respecting cross-flow fairness. Pudica introduces several judicious approaches to utilize the paced frame to probe the bandwidth utilization ratio (BUR) instead of bandwidth itself. By leveraging BUR estimations, Pudica designs a holistic bitrate adjustment policy to balance low queuing, efficiency, and fairness. We conducted thorough and comprehensive evaluations in real production networks. In comparison to the state-of-the-art methods, Pudica reduces the average and tailed frame delay by 3.1$\times$and 5.1$\times$, respectively. Meanwhile, it increases the frame bitrate by 12.1%. Pudica has been deployed in a large-scale cloud gaming platform, currently serving millions of players.