A research submitted in partial fulfillment of the requirement for the degree of Master of Engineering

Research Studies Project Report (M.Eng.) - Asian Institute of Technology, 1999

The scenario is that a bulk data transfer is being performed over a TCP connection, from a host on a local area network (LAN) to a mobile host attached to the LAN by a radio link. In (Kumar, 1998), they had assumed that packet losses in a TCP connection over a radio link are statistically independent. In (Kumar, and Holtzman, 1996), they extend this analysis to a Rayleigh fading link, which is modeled by a two state Markov model. In our work, we compare the bulk throughputs of TCP-OldTahoe and TCP-Tahoe with and without fading for various average signal-to-noise ratios. We also study the performance with link protocol (Stop-and-Wait and Selective-reject) on the wireless link, and study the effect of varying the link packet size, the number of link packet attempts, and the vehicle speed. For fixed signal-to-noise ratio, as the vehicle speed varies there are roughly 3 regions of performance: at very low speeds (pedestrian speeds) the throughput is very good; at low vehicular speeds the throughput deteriorates, and again becomes very good at higher vehicle speeds. The speeds corresponding to the various regions depend on the parameters of the link protocol.