| With the development of mobile communication technology, Internet has been extended from wired network to wireless network. The appearance of wireless broadband access technology makes multimedia real-time application possible in mobile wireless Internet. The VOD (Video-On-Demand) is one of the multimedia real-time applications. People hope to carry on VOD with guaranteed quality through mobile wireless Internet. However, because of the characteristics of opening channel and host moving in mobile wireless Internet, the bandwidth of the network is apt to fluctuate, and the data is easy to lose. These factors have great influence on the quality ofVOD.The C/S archtecture is adopted in this paper. The system is divided into two subsystems, one is server side, and the other is client side. Streaming format is used in the system. This system adopted some measures to ensure the QoS (Quality of Service) of the VOD. The TCP protocol that holds the functions of congestion control and traffic control is adopted to transmit data. The packet loss rate in mobile wireless Internet has reduced by this way. Admission control is adopted in server end by which ensured the server will not break down because of superfluous client accessing. A double buffers scheme is used in the client end of the VOD system, it adopts two buffers to manage the media data processed by the client, one is used to receive data and the other is used to render data. By these methods, the QoS of VOD system is ensured as much as it possible.Visual C++ is used to develop the VOD system in this paper. It is running on the windows 2000 platform. The functions of VOD are implemented in the system. In the course of playing, the tested movies are played out smoothly and the picture's quality is good.
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