Research On Establishing Video Communication Based On Public Switched Telephone Network

With quick development of multimedia communication technology, the vivid and dramatic videophones have gradually become the popularity which people pursue.This paper mainly researches the modulation and demodulation protocol of the H.324 communication protocol,and designs the modem software drivers based on the protocol. At last videophones can communicate on the PSTN.This paper expounds the development of the present videophone at first and establishes the foundation for the design and realization of the embedded videophone scheme on PSTN from the point of theory and technology. It introduces the videophone terminal system of the implement scheme of the software and hardware , and mainly analyses the module of the communication controlling task.Then it researches the physics layer of thevideophone-the modem driving module in detail,including the designs;development and the debugging of the correlational protocols and the software drivers.At the end of the paper, it summarizes some questions during the design process, and provids some suggestions and prospects in order to improve systematically.