Software Design For New Type IP Phone

It's a new topic how to develop IP phone service in new type HFC network. In the thesis, what was researched is IP telephone Terminal software design that based on New HFC Network.Firstly, the domestic and foreign actuality and the research signification of this topic were analyzed in the thesis. Developing the IP telephone in the new HFC network, it's urgent to develop a pronunciation terminal unit, which the cost approach the ordinary telephone. And it can complete the basic function of IP telephone and fit the new HFC network.In this thesis, two protocols-H.323 and SIP were analyzed and compared, their specialty and applicable range were made sure; Because the standard of Chinese IP phone system adopted H.323, the system also adopted it for compatibility; In this thesis, the standard of voice coding and decoding were analyzed, to improve quality of voice and reduce cost of chip, G.711 was selected, as the standard of voice coding and decoding and I2C-bus was adopted to communicate with FIST(Family Integrated Service Terminal).Having analyzed the function and specialty of the phone design, on the basis of the finished hardware, the project of software design was put forward and demonstrated in this thesis. The core of IP phone–the chips of voice coder and decoder and the MCU that chose by design are researched deeply in the thesis.The main is designing the main software of the new IP phone in the thesis. Such as I2C data memory, SPI communication, RS232, UART communication, CCU Pulse-Width Modulation, the operation of write or read of EEPORM, keyboard. And the whole and main circuit diagrams were drew. The effect of software debugged on the experiment board is ok. The software design of new IP telephone is completed.The IP phone terminal in this thesis is designed for the new HFC networks. The voice of the phone that adopts G.711 isn't compressed, so it's very clear than any IP phone; The processing of IP phone protocol is FIST, it can reduce the cost farther, make the best of digital advantage, extend plenty of digital function through SCM programming, and achieve the goal of designing a digital phone that has lower cost and higher quality finally. With the development of"Trinity of TV, Telecom and Computer Networks", the new IP phone will be a important voice terminal in HFC, it has beautiful and broad prospect in the future.