The Research And Design Of Voice Transmission Unit In Industrial Network Intercom System

With the rapid development of the internet technology, network communication applications are increasingly widespread. Now, the voice communication based on industrial intercom system has become a wider filed of applications. The traditional industrial intercom voice communication system is implemented by hardware circuit, and its use has a big limitation due to its more expensive cost. The voice communication system of this paper is designed through software programming, which has characters of a lower cost and easier upgrade. So it can be well applied in the industrial intercom system of unicast and multicast communication environments.The paper relies on the project of a company's commission. The contents are divided into two aspects:one is to complete voice communication programming, and the other is to configure network environment for multicast communication. The voice communication application of the paper is realized by making use of ORTP library and some functions for operating audio device file, audio buffer, and threads. In addition, the paper chooses some network equipments of Ruijie company to build the network environment and do some configuration for multicast communication. Afterwards, applications for multicast communication are tested in the above environment.The applications are designed in the Linux system, and the multicast network is built according to the topology of the paper. After several tests, the applications can well realize two-way voice communication and multicast voice communication. The paper states the principle of RTP and some contents related to multicast communication. According to these principles, the paper successfully realizes voice communication application. The design which is realized by calling ORTP stack functions can be used in the unicast and multicast network environments. Finally, according to the project's needs, the paper designs the diagram of network topology, builds a network environment for multicast communication, and does some tests of voice communication applications.