Optimizing TCP Performance over UMTS with Split TCP Proxy

Liang Hu, Lars Dittmann

Research output: Chapter in Book/Report/Conference proceedingArticle in proceedingsResearchpeer-review


Abstract: The TCP performance over UMTS network is challenged by the large delay bandwidth product. Large delay bandwidth product is mainly caused by the latency from the link layer ARQ retransmissions and diversity technique at physical layer which are used to cope with radio transmission errors. To cope with large delay bandwidth product, we propose a novel concept of split TCP proxy which is placed at GGSN between UNITS network and Internet. The split proxy divides the bandwidth delay product into two parts, resulting in two TCP connections with smaller bandwidth delay products which can be pipelined and thus operating at higher speeds. Simulation results show, the split TCP proxy can significantly improve the TCP performance in terms of RLC throughput under high bit rate DCH channel scenario (e.g.256 kbps). On the other hand, it only brings small performance improvement under low bit rate DCH scenario (e.g.64 kbps). Besides, the split TCP proxy brings more performance gain for downloading large files than downloading small ones. To the end, for the configuration of the split proxy, an aggressive initial TCP congestion window size (e.g. 10 MSS) at proxy is particularly useful for radio links with high data rates DCH channels with large delay bandwidth product.
Original languageEnglish
Title of host publicationCommunications and Networking in China
VolumeVolume 26
Publication date2009
ISBN (Print)978-3-642-00204-5
Publication statusPublished - 2009
Event1st International Business Conference - Hangzhou, China
Duration: 1 Jan 2008 → …
Conference number: 1


Conference1st International Business Conference
Period01/01/2008 → …
SeriesCommunications in Computer and Information Science


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