Paper Info
Title
GPRSWeb: optimizing the web for GPRS links
Abstract
The General Packet Radio Service (GPRS) is being deployed by GSM network operators world-wide, and promises to offer users "always-on" data access at bandwidths comparable to that of conventional fixed-line telephone modems. Unfortunately, many users have found the reality to be rather different, experiencing very disappointing performance when, for example, browsing the web over GPRS.In this paper we investigate what causes the HTTP protocol and its underlying transport TCP to underperform in a GPRS environment. We examine why certain GPRS 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 also show that many web browsers tend to be overly aggressive, and by opening too many simultaneous TCP connections can aggravate matters.We present the design and implementation of GPRSWeb - a mobile HTTP proxy system that mitigates many of the performance problems with a simple software update to a GPRS mobile device. The update is a 'client proxy' that sits in the mobile device, and communicates with a 'server proxy' located at the other end of the GPRS link close to the wired-wireless border. The dual proxy architecture collectively implements a number of key enhancements - an aggressive caching scheme that employs content-based hash keying to improve hit rates for dynamic content, a preemptive push of web page support resources to mobile clients, resource adaptation to suit client capabilities, delta encoded data transfers, DNS lookup migration, and a UDP-based reliable transport protocol that is specifically optimized for use over GPRS. We show that these enhancements result in significant improvement in overall WWW performance over GPRS.
Year
DOI
Venue
2003
10.1145/1066116.1066128
MobiSys
Keywords
Field
DocType
gprs link close,server proxy,proxy system,mobile client,gprs mobile device,gprs environment,mobile device,certain gprs network characteristic,dual proxy architecture,client proxy,web pages,data access,general packet radio service,data transfer,dynamic content
GPRS core network,Web page,Computer science,Computer network,Real-time computing,Hypertext Transfer Protocol,Dynamic web page,General Packet Radio Service,World Wide Web,GSM,Mobile device,Access Point Name,Operating system
Conference
Citations 
PageRank 
References 
22
2.33
17
Authors
3
Name
Order
Citations
PageRank
Rajiv Chakravorty149947.06
Andrew Clark2222.33
Ian Pratt35420506.92