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Absfract-Many current wireless wide area packet data networks are characterized by very low and variable bandwidths, very high and variable delays, significant non-congestion related loss, asymmetric uplink and downlink channels, and occasional blackouts. Additionally, the majority of the latency in a WWAN connection is incurred over the wireless link. Under such operating conditions;most contemporary wireless TCP algorithms do not perform very well.In [7], we presented WTCP, a reliable transport protocol that is designed to operate efficiently and fairly over wireless wide area networks. WTCP is rate-based, uses only end-to-end mechanisms, performs rate control at the receiver, and uses the ratio of sending rate to receiving rate as as the primary metric for rate control. In this paper, we evaluate the performance of WTCP over CDPD networks.We have implemented and evaluated WTCP over the CDPD network, and also simulated it in the ns-2 simulator. Our performance results indicate that WTCP can improve on the performance of comparable algorithms such as TCP-NewReno and TCP-Vegas by between 20% to 200% for typical operating conditions.

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In this paper, we present a core-stateless framework for allocating bandwidth to flows based on their requirements which are expressed using utility functions. The framework inherently supports flows with adaptive resource requirements and intra-flow drop priorities. The edge routers implement a labeling algorithm which in effect embeds partial information from a flow's utility function in each packet. The core routers maintain no per-flow state. Forwarding decisions are based a packets label and on a threshold utility value that is dynamically computed. Thus the edge and core routers work in tandem to provide bandwidth allocations based on a flow's utility function. We show how the labeling algorithm can be tailored to provide different services like weighted fair rate allocations. We then show the performance of our approach using simulations.