Service differentiation through end-to-end rate control in low bandwidth wireless packet networks

With the increased commercial deployment of wireless networks, the issue of service differentiation among flows in a wireless/wireline network is becoming important. While many wireline solutions for service differentiation depend on end to-end rate control upon packet loss, this approach does not work well for wireless networks because packet losses do not necessarily indicate congestion in the network in the wireless domain. In a related work, we presented WTCP, a reliable transport protocol that is designed to operate efficiently and fairly over wireless wide area networks. The rate control algorithm in WTCP is based on the use of the ratio of the inter-packet separation at the receiver and the sender as the metric for detecting and reacting to congestion. In this paper, we generalize the rate control mechanisms of WTCP to support both reliable and unreliable flows, and to provide service differentiation among flows. We present preliminary results using the ns2 simulator to show that our rate control algorithm provides service differentiation for low bandwidth wireless networks and scales well with the variations in the link loss characteristics