Design and Evaluation of Hybrid Congestion Control Mechanism for Video Streaming

In recent years, video streaming services over TCP, such as YouTube, have become more and more popular. TCP New Reno, the current TCP standard, performs greedy congestion control, which increases the congestion window size until packet loss occurs. Therefore, because TCP transmits data at a much higher rate than the video playback rate, the probability of packet loss in the network increases, which in turn takes bandwidth from other network traffic. In this paper, we propose a new transport-layer protocol, called TCP Stream, which solves the problem of TCP in video streaming. TCP Stream performs a hybrid congestion control that combines the loss-based congestion control, which uses packet loss as an index of congestion, and the delay-based congestion control, which uses delay as an index of congestion. Simulation and experimental results show that TCP Stream transmits data at the adjusted rate, unlike TCP New Reno, and does not steal bandwidth from other network traffic.