A Data Audio Park Broadcasting System Design And Research Of Ip-based

With the development of electronic technology, the predominance of digital signal becomes obvious, such as controllable, safe and well anti-jamming. Hereby the process of processing and transmitting audio signal is carrying out in digital mode, replacing analog signal. As the main LAN technology, the Ethernet has been applied to more and more aspects, which makes network transmission convenient. In addition, when broadcast and multicast are used, the efficiency of transmission is improved, network bandwidth is saved, network costs are reduced.Combining the advantages of digital audio and the advantages of network, this topic completed the design of an IP-based network audio processing system. The system uses exiting convenient network facilities to transmit audio signals, to supply power over Ethernet in accordance with the IEEE802.3af standard. Multi-channel audio signals are transmit in the digital mode, which avoids the traditional multi-channel audio processing system's shortcomings of laying multiple pipelines and ensure the quality of signals. Audio data sub-regional transmission was increased because of the application of multicast.This system includes two part, software on computer and network audio terminal. This paper mainly introduces network audio terminal. It can receive audio packets that come from Ethernet, and deal with them in link layer, network layer and transport layer. Finally, the terminal will convert present digital audio signal into stimulant signal and export them. And the paper mainly researches the following three aspects.(1) The hardware realization of network audio terminalUsing single chip 89C58 and highly integrated Ethernet controller chip RTL8019AS with 16 bit precision D/A DAC8541 as the core device. Utilizing Intel company EEPROM 24C512 and SRAM MCM6225 as the expend memory to build the hardware.(2) The realization of TCP/IP protocol on single chipAnalyzing the different functions and unlike realizations of each sub protocol and considering limited hardware resource of single chip. The TCPIP protocol is carried out concisely on single chip. This concise protocol includes following part: ARP protocol module, ICMP protocol module, TCP protocol module, UDP protocol module and HTTP protocol module.(3) The realization of audio terminal function based on TCP/IP protocolBasing on the present TCPIP protocol, we realize how to receive digital audio packets from Ethernet and take order with them. In UDP protocol module, we carry out the audio conversion from digital signal to stimulant signal. And when user contacts with terminal by IE, the HTTP module mainly takes charge to manage user's input data.