Adaptive Video Streaming Over Heterougeneous Networks

It has been quite a long time since the birth of Internet. Its rapid development has very large impact on people's life and their working ways. Accompany the maturity of the multimedia technologies and the continuing revolution of the network technologies, people now are no longer satisfied with the simple communications only by characters. Video and audio information are becoming more and more important on the Internet. The transmitting of multimedia streams, such as video data and audio data, require good communication quality of service. This is necessary to ensure the acceptable media effects to the clients and is based on the reasonable network parameters, such as the width, the jitter, the delay and so on. Meanwhile, other transmitting data on the network will influence the multimedia information in some level. On the other hand, Internet is composed of various network technologies which all offer quite different features and services. It is a quite challenging task to make a balance between the transmitting quality of service and the network capacity itself. Especially, the continuing transmit of multimedia data over heterogeneous networks is a valuable research point.There are two major ways to ensure the video transmitting quality of service nowadays. One is using the video coding methods and another is make the network parameters adapt to the video streaming. The mechanism in this thesis is mainly focused on the second way. One of the key elements about video transmitting is the network equipment and routers are the most important ones. To change facilities now and then in order to achieve the ideal result during academic researches is completely unpractical. On the contrary, the simulation tool is a good choice. The thesis compare some of the most popular simulation tools and describe the Click Modular Router in detail.This thesis has completed two tasks: by using the ordinary PCs as the hardware platform and the simulation tool called Click Modular Router, I constructed a heterogeneous network environment, consisting of the Ethernet (IEEE802.3) and the Wifi Network (IEEE802.11). I also used the opensource software VideoLAN as the video server in the system. On this basis, I designed a adaptive video transmitting mechanism to ensure the client's video quality of service.