Incorporating proxy services into wide area cellular IP networks

Zhimei Jiang, Li Fung Chang, Byoung Jo J. Kim, Kin K. Leung
2001 Wireless Communications and Mobile Computing  
Performance enhancing proxies have drawn considerable interests from the network community a s a n e ective approach to improve user experience in cellular networks. However, previous research has been focusing on the design of proxy servers as well as the functions that these servers provide. In this paper, we study the placement of proxy servers, especially the approach of incorporating proxies into cellular networks, which allows better, faster, and more secure proxy services. We discuss
more » ... ous factors that must be considered when placing proxies inside cellular networks, including the information requirements of the proxies, the network requirements for supporting the proxy functions, and mobility management. Using GPRS as an example, we l a y out a procedure for adding proxies into data transmission path in cellular networks. One possible approach is to modify applications, protocols, and other related components for the wireless environment, which c a n b e a v ery slow and costly process. An alternative approach i s t o m a k e use of performance enhancing proxies 8, 17, 29 . In this case, mobile users communicate with the performance enhancing proxies which in turn exchange information with the destination servers on behalf of the mobile users. At the proxy, information from the original server is converted to make it suitable for the wireless environment, while at the same time taking into account of user's preference and the characteristics of the device in use. For the web browsing example mentioned above, proxies can reorganize the layout of web pages and shrink images to t into the small display of PDA devices, which reduces bandwidth consumption at the same time. Based on user's preference, proxies can also eliminate graphics completely. Recent development in mark-up languages, including XHTML Extensible HTML and XML Extensible Markup Language, will make this type of transformations more e ective 9, 31 . Another advantage of using performance enhancing proxies is that, proxy servers can perform channel adaptation for certain data streams. With channel adaptation the performance of audio and video applications can besigni cantly improved 13, 21, 24 .
doi:10.1002/wcm.20 fatcat:a4xkwngztjahnhrcrwfhzq3eyy