Efficient multimedia data transmission over heterogeneous networks

Abstract

This thesis tries to make a thorough investigation of the multimedia data transmission performance in three different kinds of network environments, the internet, the WLAN and the 3G mobile networks. Some novel approaches have been proposed to improve the transmission efficiency. According to the different environments where the multimedia contents are being transmitted, my study focuses on the following three distinct topics: (1) Hierarchical Web Caching on the internet. In the core network of the internet, web caching plays an important role in the transmission of multimedia content. In this part, I made an investigation on the performance of hierarchical web caching and proposed possible solutions to improve the caching performance. (2) Bandwidth detection in WLAN. Different from wired network, the wireless bandwidth can vary greatly with time, which largely affects the transmission performance of multimedia data. Thus in this part, an efficient bandwidth detection method is proposed to provide accurate wireless bandwidth information for multimedia applications. (3) Multimedia Data Transmission in 3G Mobile Network. We have made an efficient implementation of the 3G-324M protocol stack for multimedia communication. A novel serialization approach and some enhancements have been added to the H.223 module, so as to improve the transmission performance and efficiency of the multimedia data. An excellent prototype system anyConference is also developed.