A new high-performance TCP friendly congestion control over wireless networks

In recent years, new delay-based congestion control mechanisms like Caia-Hamilton Delay (CHD) or Caia Delay-Gradient (CDG) are becoming popular due to their effectiveness even over wireless links. CHD and CDG are designed to behave friendly with conventional TCP NewReno flows. However, due to their delay-based window update mechanisms, CHD or CDG performance is often vulnerable to the co-existing aggressive TCP NewReno flows. In addition, in case of CHD, it is practically very difficult to choose the optimum values of tuning parameters with a view to ensuring the expected performance. In this paper, we therefore propose a new mechanism to overcome the above issues. We name it as Wireless Friendly Congestion Control (WFCC). Our objective is to devise a congestion control scheme that is (i) friendly with TCP NewReno flows over wireless links when deployed together, (ii) free from delicate operational parameters and (iii) robust against link errors under a wide range of network buffer space. We conduct a thorough evaluation of our proposed approach by simulation as well as emulation. Results show that WFCC (i) can lead up to 250% improvement in performance compared to TCP NewReno schemes and (ii) are friendly with TCP NewReno flows over wireless links.