The Study On Embedded Home Communication Platform Based On Network

Based on a practical research program, the dissertation make deep research into embedded platform of home communication based on network. The article analyses some key technology in the system and put forward plan.There are tow problems lying in the home-communication platform now, one is to add new function, and the other is to need standard protocol of communication. Having to solve these tow problems, and having been enlightened from the system of VDF and VoIP system, I researched it' s key area of VDF coding and decoding and the protocol of network transmitting.Pointing to the feature of EMS memory in embedded system, the protocol of VDF coding and decoding used the MPEG4 protocol with high compressibility, which embodied by TMS320C6205 of DSP chip. And the C6205 can exchange the data with the CPU faster than C6201 with no PCI module.What the most important in the paper is the protocol of network communication, so it has adopted the SIP protocol with simple construction and perfect expansibilities. Because the SIP protocol is based on VoIP system, if it is applied to the home-communication platform, it could not only facility to unite the protocol but also reduce the cost of the system. In the paper, the SIP protocol has been illuminated in detail, as well, the developed software of SIP in Linux has been introduced. These opened original codes could be supported well, so it is fit for the developing program test.The reliability of communication platform on which the video signal transmits in IP net is ensured by RTP/RTCP. The RTP fulfills to transmit real-time data while RTCP provides controlling info of transmitting qualities.In the paper, the MCU adopted is S3C2410 chip based ARM920T kernel, which provides general interfaces with many functions, so it could meet diverse demands of home-communication platform. The frequency of CPU is up to 203Mhz so that the board could be fit for the OS of WinCE or Linuxand could solve much complicated info.The development of user' s program has been completed in the environment of cross compiling in Linux. Except for the program of VDF code, the main program provides initialization of the system, task dispatch, GUI, media signal transmitting, interface management, network communication, etc.The QT/embedded has been adopted in developing program of user interface for the embedded system, which is the developing software for Linux specially. It has the functions of network communication and multi-thread management. The paper has shown the QT compiling process to the user program and part explanation.