A study of TCP performance in wired-cum-ad hoc environments

Abstract

Ad hoc networks may operate in a standalone fashion, or may be connected to wired networks, such as the Internet. We call the latter wired-cum-ad hoc networks. This thesis provides an in-depth study on TCP performance in wired-cum-ad hoc networks. Two important properties of TCP, throughput and fairness, are both addressed. First, a comprehensive evaluation of different TCP algorithms performance in wired-cum-ad hoc environments is done, and the results give clear answers to questions like which TCP algorithm should be deployed in this specific scenario, and how to tune TCP parameters to optimize its performance. Moreover, this thesis also presents a scheme that successfully eliminates the severe unfairness between TCP flows spanning wired and IEEE802.11-based wireless ad hoc networks. Simulation results show that our scheme improves the fairness between TCP flows greatly without incurring much throughput loss.