What is network communication technology?
Network communication technology（ NCT:Network Communication Technology refers to the technology of collecting, storing, processing and transmitting data in the form of graphics and text through computers and network communication equipment, so as to fully share information resources. Communication network technology communication network is a kind of communication system in which communication endpoints, nodes and transmission links are organically connected with each other to provide connection or non connection transmission between two or more specified communication endpoints. According to different functions and uses, communication network can be divided into physical network, service network and support management network. Physical network is an entity structure composed of user terminal, switching system, transmission system and other communication equipment. It is the material basis of communication network, also known as equipment network. The user terminal is the peripheral equipment of the communication network. It transforms the various forms of information sent by the user into electromagnetic signals, and sends them to the communication network for transmission, or transforms the electromagnetic signals received from the communication network into user identifiable information. According to their different functions, user terminals can be divided into telephone terminals, non telephone terminals and multimedia communication terminals. Telephone terminal refers to ordinary telephone, mobile telephone, etc.; non telephone terminal refers to telegraph terminal, fax terminal, computer terminal, data terminal, etc.; multimedia communication terminal refers to terminal equipment that can provide at least two types of information media or functions, such as videophone, video conference system, etc. The exchange system is the distribution center of all kinds of information and the key link of information exchange. Transmission system is the channel of information transmission. It connects the user terminal with the exchange system and the exchange system to form a network. Transmission system can be divided into wired transmission system and wireless transmission system according to different transmission media. The transmission of signal is realized by the transmission of electromagnetic wave along some tangible medium in wired transmission system. Wireless transmission system is based on the propagation of electromagnetic waves in the air to achieve signal transmission. Business network refers to the service function of communication network, which is used to dredge telephone, telegraph, fax, data, image and other communication services. According to its business types, it can be divided into telephone network, telegraph network, data network, etc. Telephone network is the basis of various services. Telegraph network is formed by adding telegraph multiplexing equipment in telephone circuit. Data network can be composed of telephone circuit or special circuit for transmitting data signal. The service network has a hierarchical structure, that is, different levels of switching centers are set up in the service, and the switches are connected with each other in a certain way according to the service flow, flow direction, technical and economic analysis. The support management network is a network formed to ensure the normal operation of the business network, enhance the network function and improve the service quality of the whole network. The corresponding control, monitoring and signaling signals are transmitted in the support management network. According to its different functions, it can be divided into signaling network, synchronization network and management network. Signaling network is composed of signaling points, signaling transfer points, signaling links, etc. it is designed to transmit signaling for users of common channel signaling system. The synchronization network provides synchronization control signals for the clocks (or carriers) of all communication devices in the communication network to make them work at the same rate (or frequency). Management network is a software and hardware system established to maintain the normal operation and service of communication network. It can be divided into traffic management network and transmission monitoring network.