Protocol Replacement Proxy for 2.5 and 3G Mobile Internet

Abstract

Providing mobile Internet access in GPRS and UMTS networks is not an easy task. The main problem is in rather challenging network conditions (Inamura, Montenegro, Ludwig, Gurtov, & Khafizov, 2003). Latency in these networks could be an order of magnitude higher than in wired networks, with round-trip time (RTT) reaching up to one second. Moreover, there occur delay spikes in the network, when latency can exceed average RTT several times (Gurtov, 2004). Furthermore, in wireless networks, the risk of experiencing packet losses is considerably higher in comparison to that in wired networks. This is because packets can easily be lost due to corruption, either during deep fading leading to burst losses, or cell reselections, resulting in a link black-out condition. Such characteristics of wireless cellular networks significantly affect performance of the principal Internet protocol—TCP—as it was designed to work in conditions of low-latency reliable networks.