Streaming Media Application Layer Multicast Technology

With the development and combination of embedded systems and internet, information technology will provide people with more convenience. Compared with traditional solutions, embedded devices don't have enough resources, so it can hardly use or provide traditional internet services. Therefore embedded-internet application must beware of these facts and do some adaptive changes to make it more suitable for embedded devices.This dissertation focused on this feature of embedded-internet application, researched wireless network and WAP(Wireless Application Protocol) from the viewpoint of service user, and researched multimedia streaming model on embedded-internet from the viewpoint of service provider.At first, the dissertation introduced features of mobile-internet and WAP, which is designed to overcome the shortcomings of wireless networks. A framework of client WAP protocol stack was designed and the connectionless mode of WAP was implemented.Then, several key technologies of streaming were introduced. The capability bottleneck of streaming server in traditional centralized service architecture (Client-Server model) was anaylized. The bottleneck is more serious for embedded streaming server, such as embedded web camera, because of its less capability. For these problems, several technologies were provided. Application layer multicast is the most attractive one among them because it is cheap and easy to deploy.The dissertation presented a gossip-based application layer multicast model: valepp, and verified its correctness by simulation. The prototype of the model had been implemented on LAN and will be deployed on embedded-internet in future work.