  Presented in this paper is the solution to the problem that arises when the
TCP/IP protocol suite is used to provide Internet connectivity through mobile
terminals over emerging 802.11 wireless links. Taking into consideration the
strong drive towards wireless Internet access through mobile terminals, the
problem of frequent disconnections causing serial timeouts is examined and
analyzed, with the help of extensive simulations. After a detailed review of
wireless link loss recovery mechanism and identification of related problems, a
new scheme with modifications at link layer and transport layer is proposed.
The proposed modifications which depend on interaction between two layers (i)
reduce the idle time before transmission at TCP by preventing timeout
occurrences and (ii) decouple the congestion control from recovery of the
losses due to link failure. Results of simulation based experiments demonstrate
considerable performance improvement with the proposed modifications over the
conventional TCP, when a wireless sender is experiencing frequent link
failures.
