With the growing use of PDAs, mobile phones and other similar devices for accessing the web, it is important to ensure that data delivery mechanisms are well adapted to such heterogeneity. While a high resolution image is suited for viewing at a regular PC, it is clearly not the best choice for a small-screen gray scale PDA device. There is work done on converting the data to appropriate formats, the process called transcoding. However, there is no one accepted delivery mechanism. Some require servers to transcode data offline and keep all possible data versions and some suggest server doing on-the-fly transcoding for every request received.
In this work, we argue that the best suited mechanism is to install transcoding engines at intermediate proxies. These proxies would be responsible for interpreting user request and getting the best suited data for the device making the request. We developed an adaptive proxy, which makes decision whether to download the appropriate version from the server or to transcode some local version, based on dynamic system parameters like the current CPU load on the proxy, the network delays etc. We also integrated efficient caching mechanisms, with a new cache replacement policy which takes into account the utility of the data based on its accesses and also the number of versions it can be transcoded into, to satisfy other incoming requests.
Our results showed that we can get significant performance enhancements using such mechanisms. Also, we show that even simplistic adaptive policies, with low overheads of their own, are enough to get those performance improvements. The source code for the proxies can be obtained by emailing the first author.
Aameek Singh
Abhishek Trivedi
Krithi Ramamritham
Prashant Shenoy
Aameek Singh, Abhishek Trivedi, Krithi Ramamritham, Prashant Shenoy, " PTC: Proxies that Transcode and Cache in Heterogenous Web Client Environments", World Wide Web: Internet and Web Information Systems Journal by Kluwer Publishers, Volume-7, Issue-1, 2004. (Invited - Extended version of WISE02)
Aameek Singh, Abhishek Trivedi, Krithi Ramamritham, Prashant Shenoy, "PTC: Proxies that Transcode and Cache in Heterogenous Web Client Environments", Proceedings of the third IEEE International Conference on Web Information System Engineering (WISE), Singapore, Dec 2002. (A Best Paper) |Slides|
Girma Berhe, Lionel Brunie and Jean-Marc Pierson, "Planning-Based Multimedia Adaptation Services Composition for Pervasive Computing", SITIS 2006. [pdf]
C. Canali, V. Cardellini, R. Lancellotti, "Content Adaptation Architectures Based on Squid Proxy Server", World Wide Web Journal, Vol-9(1), 2006. [html]
Vidyut Samanta, Ricardo Oliveira, Advait Dixit, Parixit Aghera, Petros Zerfos, Songwu Lu, "Impact of Video Encoding Parameters on Dynamic Video Transcoding", COMSWARE 2006. [pdf]
Thijs Lambrecht, Bart Duysburgh, Tim Wauters, Filip De Turck, Bart Dhoedt and Piet Demeester, "Optimizing multimedia transcoding multicast trees", Elsevier Computer Networks Journal, Vol 50(1), 2006. [html]
Praveena Jayanthi, "Scalable Proxy Architecture for Mobile and Peer-to-Peer Networks", Masters Thesis, Georgia State University, 2005. [html]
R. Jana, C. Lina, M. Chern, "An optimization model for Web content adaptation", Elsevier Computer Networks, Vol-50(7), 2005. [html]
L. Bradford, "Unanticipated Evolution of Web Service Provision Software using Generative Object Communication", PhD thesis, Queensland University of Technology, 2006. [pdf]
Mu Su, Chi-Hung Chi, "Architecture and Performance of Application Networking in Pervasive Content Delivery", ICDE 2005. [pdf]
Yun Huang, Shivajit Mohapatra, Qi Han, Nalini Venkatasubramanian, "QoS Aware Resource Discovery in Mobile Environments", chapter VI of the book on "Mobile Middleware", Chapman and Hall/CRC Press, 2005. [pdf]
D. Gujjar, A. Thawani, S. Gopalan, and S. V, "An Efficient Event Management System for Distributed Multimedia Services", Internet and Multimedia Systems and Applications, EUROIMSA, 2005. [html]
Claudia Canali, Valeria Cardellini, Michele Colajanni, Riccardo Lancellotti, "Performance Comparison of Distributed Architectures for Content Adaptation and Delivery of Web Resources", SIUMI 2005. [pdf]
Byoung-Jip Kim, Kyungbaek Kim, Daeyeon Park, "The Content-Aware Caching for Cooperative Transcoding Proxies", ICOIN 2005. [pdf]
Claudia Canali, Valeria Cardellini, Michele Colajanni, Riccardo Lancellotti, Philip S. Yu, "A Two-Level Distributed Architecture for Efficient Web Content Adaptation and Delivery", 2005 Symposium on Applications and the Internet (SAINT'05). [pdf]
Mu Su, Chi-Hung Chi, "Application Networking . An Architecture for Pervasive Content Delivery", 9th Int'l Workshop on Web Content Caching and Distribution (WCW) 2004 [pdf]
Xiu Wu, Kian-Lee Tan, "A hash-based collaborative transcoding proxy system", Data and Knowledge Engineering, Vol 51, Issue 2, 2004. [pdf]
Grzegorz Hryn, Zbigniew Jerzak, "Adaptive Bandwidth Driven Content Delivery for WWW Clients", 12th Conference on Computer Networks and Computer Systems, 2004 [pdf]
Claudia Canali, Valeria Cardellini, Michele Colajanni, Riccardo Lancellotti, Philip S. Yu, "Cooperative Architectures and Algorithms for discovery and transcoding of multi-version content", 8th Intl' Workshop on Web Content Caching and Distribution (WCW) 2003 [pdf]
Michele Colajanni, Riccardo Lancellotti, "System architectures for Web content adaptation services", Web Systems Invited Article, IEEE Distributed Systems Online [html]
Seminar, Multimedia Laboratory, Sogang University, Korea. [html]
Vidyut Samanta, "A Study of Mobile Messageing Services", Masters Thesis, UCLA. [pdf]
Humeyra Topcu-Altintas, "Overload-Driven Mobility-Aware Cache Management in Wireless Environments", Masters Thesis, University of California, Irvine. [doc]
Francisco J. Gonzalez-Castano, Rafael Asorey-Cacheda, Manuel Vilas-Paz, Felipe Gil-Castineira, Enrique Costa-Montenegro, Roberto Perez-GarcĂ,"QoS provisioning in mobile video services with satellite sources", 2nd International Workshop of Action 280 Joint with COST272 [pdf]
Thong Chanchaem, "A Survey on Internet Content Transcoding for Universal Access" [html]
Aameek Singh <aameek[AT]aameeksingh.com>
© 2007 Aameek Singh