SWRR: The Link Scheduling Algorithm Based on Weighted Round-Robin

Abstract
With the rapid development of the Internet, people pay more and more attention to the protection of privacy. The second-generation onion routing system Tor is the most commonly used among anonymous communication systems, which can be used to protect user privacy effectively. In recent years, Tor's congestion problem has become the focus of attention, and it can affect Tor's performance even user experience. Firstly, we investigate the causes of Tor network congestion and summarize some link scheduling algorithms proposed in recent years. Then we propose the link scheduling algorithm SWRR based on WRR (Weighted Round Robin). In this process, we design multiple weight functions and compare the performance of these weight functions under different congestion conditions, and the appropriate weight function is selected to be used in our algorithms based on the experiment results. Finally, we also compare the performance of SWRR with other link scheduling algorithms under different congestion conditions by experiments, and verify the effectiveness of the algorithm SWRR.