Enhancements on Router-Assisted Congestion Control for Wireless Networks

This paper addresses two challenges that are encountered when applying router-assisted explicit-feedback congestion control to wireless networks. The first challenge is how to distinguish between the two kinds of packet loss (non- congestion loss and congestion loss) in wireless networks and how to react to them properly. The second challenge is how to probe the unknown bandwidth capacity of wireless links which is required in calculating the router feedback. Some practical and novel enhancements on router-assisted congestion control in such environments are introduced in this paper. We have implemented these enhancements in a router-assisted congestion control protocol termed QFCP. Extensive simulation experiments using ns-2 will demonstrate that QFCP can fairly and efficiently allocate wireless bandwidth resources among competing flows in heterogeneous networks.