A mobile-aware transmission control protocol (TCP) for wireless communications
Pamela Chia-pei Lee · Summit (Simon Fraser University) · 1996
The current Transmission Control ProtocoVInternet Protocol (TCPLP) protocol suite is not designed to support mobile hosts and wireless links, since host migration will result in a loss of connection.All existing network applications must then be restarted.Several solutions have been proposed to provide for host mobility, but they all confine mobility support knctions to the IP layer.In theory, mobile hosts can use existing higher-layer protocols such as TCP with any one of these proposed solutions to communicate with the fixed networks.However, this approach can degrade TCP performance significantly.The reason is that TCP cannot differentiate the effects of network mobility from the effects of network congestion.Whenever a packet loss is caused by cell handoffs or by unreliable wireless links, TCP will use the wrong remedy, that is, the congestion control procedures, to alleviate the impact of mobility.In this thesis, we propose a mobile-aware TCP that can distinguish mobility-related packet losses from congestion-related ones and provide mobility alleviation procedures to control the effects of mobility.We also develop analytical and simulation models to evaluate the proposed scheme.Both analytical and simulation results show that our scheme can effectively improve TCP performance in mobile computing environments.14 .The behaviors of the TCP sequence number of the normal TCP. the fast retransmission scheme.and the proposed scheme in the error environment .......... 39 15 .The behaviors of the TCP congestion window of the normal TCP. the fast retransmission scheme.and the proposed scheme in the error environment ..........