Freeze TCP with timestamps for fast packet loss recovery after disconnections

TCP optimization for wireless networks, for dealing with packet losses and disconnections due to fading, shadowing and handoffs, ideally should maintain TCP end-to-end semantics with minimal dependence on intermediate nodes. This paper presents such a mechanism that uses disconnection duration estimates at the receiver, derived from timestamps, to avoid an increase in the retransmission timeout (RTO) estimate at the sender following disconnections. Simulation results are presented to illustrate the problem, and to show that the proposed modification significantly improves performance. Incorporating this into the recently proposed Freeze-TCP scheme, which uses disconnection predictions at the receiver, is shown to increase robustness to packet losses during disconnections. (C) 2003 Elsevier B.V. All rights reserved.