The Design And Realization Of Digital Voice Network Meeting System Based On Special Network

This paper studied the problems of design and realization of digital voice network meeting system which based on special network. The system must have processing speed, good extensibility and text transimission. This paper introduced the ideals of a special network structure , embedded real-time operation system, embedded protocol stack, and standard WDM hardware driver design.The digital voice network meeting system's function and real-time require were analyed. We used the special network based on RS485 bus structure to realize voice signal transmission, which reduced the network complexity and made the design simple and stabile. We designed the digital voice network meeting system's meeting terminal hardware and control interface board based on the special network. We used the traditional method of DSP+FPGA build up the meeting terminal hardware structure. It was FPGA that we processed the voice data stream and realized the network interface. We also designed the multitask software in DSP based on DSP/BIOS real-time operation system. The control interface board communicated to computer with USB interface. We designed WDM driver on USB bus which made the computer control the whole system through the USB interface. For the transmission of control command signal, we realized the porting LwIP, embedded TCP/IP stack, to DSP/BIOS based on the special network structure.It is proved that the design of system is successful by actual testing of hardware and software.