One-way communication service for transmitting simple information. There are public and private systems. It mainly transmits data information, and there are two main display modes: numbers and Chinese characters. Public wireless paging service generally adopts the method of monthly billing.
2. Mobile phone service
Mobile phones are used to communicate with each other through base stations and automatic switching equipment. It can communicate with domestic and foreign telephone users by connecting to the public telephone network. Generally, the billing method adopts monthly subscription system and timing system.
3. Dispatching telephone service
Within the prescribed scope, the wireless telephone system of a system or a unit is mainly used for production command and dispatch and work contact.
4. Cordless telephone service
Using cordless telephone with wireless channel instead of telephone line enables users to realize mobile phone service in a limited range.
Extended data
Related technologies:
1, OFDM technology. It is actually a multi-carrier modulation MCM. Its main principle is: the high-speed serial data to be transmitted is converted into a low-speed data stream transmitted in parallel on n subchannels, and then modulated by n orthogonal carriers of 1 picometer, and then superimposed and sent. The receiver carries out coherent reception with coherent carrier, and then restores the original high-speed data through parallel/serial conversion.
2. Multi-input and multi-output technology. MIMO technology is a major breakthrough of smart antenna technology in the field of wireless mobile communication. This technology can double the capacity and spectrum utilization rate of the communication system without increasing the bandwidth, and it is one of the core technologies of the next generation mobile communication system.
3. Switching technology. Handover technology can realize mobile terminals to cross between different cells and communicate between different frequencies, and how to select channels when the signal quality decreases. It is the basis for future mobile terminals to establish reliable communication between numerous communication systems and mobile paging. Mainly divided into hard handover, soft handover and softer handover. Hard handoff occurs between base stations of different frequencies or different systems.
Baidu encyclopedia-mobile communication service