Flow Aggregation for Enhanced TCP over Wide Area Wireless

Abstract— Throughout the world, GSM cellular mobile networks are being upgraded to support the “always-on” General Packet Radio Service (GPRS). Despite the apparent availability of levels of bandwidth not dissimilar to that provided by conventional fixed-wire telephone modems, the user experience using GPRS is currently considerably worse. In this paper we examine the performance of TCP and HTTP over GPRS, and show how certain network characteristics interact badly with TCP to yield problems such as: link under-utilization for short-lived flows, excess queueing for long-lived flows, ACK compression, poor loss recovery, and gross unfairness between competing flows. We present the design and implementation of a transparent TCP proxy that mitigates many of these problems without requiring any changes to the TCP implementations in either mobile or fixed-wire end systems. The proxy transparently splits TCP connections into two halves, the wired and wireless sides. Connections des...

• Type: Conference
• Year: 2003
• Where: INFOCOM
• Authors: Rajiv Chakravorty, Sachin Katti, Ian Pratt, Jon Crowcroft
• Keywords: Communications, General Packet Radio Service, INFOCOM 2003, TCP Connections, Transparent Tcp Proxy