The Study Of An Intelligent Non-central Switching Explosion-proof Amplifying Call And Telephone Talk System

Most of the presently-used telephone communication system is the central-switching one which adopts the star topological structure and whose user sets are connected to the switch through their respective telephone lines. The whole calling process of the system is just like that the calling party calls the called one through dialing, and then the called party picks up the telephone after hearing the ring. The system has such disadvantages as follows:1. The wiring installation is complex and the engineering cost is high.2. The cost of the telephone lines is high, while the utilization factor of them is low.3. The system is not very reliable.4. The dialing is slow and the system can't ensure the calling party fast and accurately put through the called one who is asked for receiving.5. The bell ring is so low that the workers can't hear in the large-scaled working space with strong noise.In another way, the presently-used telephone communication system commonly hasn't the function of explosion-proof. Some central-switching system has the function of amplifying call, however, the system has such disadvantages as calling through dialing and so on. Though the wireless intercom can be used to realize industrial communication, yet it exists the requisitions of such as applying for frequency points and communicating with only the people who carry intercoms. What's more, the quality of the communication by intercom is not ideal.The working space in the fields such as oil, chemistry, metallurgy, coal mining and medicine always requires a communication system which can make sure the calling party shortly and easily get in touch with the called one in the inflammable and explosive, large-scaled and strong-noised working space. All the above systems can't satisfy the requisitions, so a novel type of industrial communication system should be developed.To adopt the technique of the multi-channels sharing is an effective method to increase the system's capacity and the utilization factor of the channels. The basic principle of the multi-channels sharing is that all the n channels can be used by all the m users (m>n). When k (k