Window Adaptive TCP for EGPRS Networks

INTRODUCTION With the explosive growth of cellular voice services in the past few years, it is expected that there will be a tremendous demand for wireless data service in the future. When the medium that people use to access to the Internet changes from wireline to wireless networks, many protocols that were originally developed in the wireline environment will face the new challenges unique to the wireless environment. As a vital part of the Internet transmission protocol, TCP has received a lot of attention and many research studies investigate its performance over wireless links in various wireless networks [1, 2, 3, 4]. TCP was originally designed for wireline networks. In a mobile environment, new problems emerge due to the difference between wireline and wireless networks. In GPRS/EGPRS and other 3G cellular systems, there is a new feature: the use of variable rate channel coders. Unlike GSM that only supports circuit-switched data transmission with rates up to 9.6 kbps, EGPRS offers packet-switched data transmission with rates ranging from 8.8 kbps to 59.2 kbps per channel by choosing appropriate coding schemes according to the condition of the radio link. More over, EGPRS allows a