Introduction: As China Radio and Television officially launched the number release on June 27, users encountered some problems after obtaining the number card. This article gives answers from the evolution of 1G to 5G mobile networks, as well as the topology of the 4G/5G network for relevant personnel to refer to.
1. Mobile communication principle
Mobile communication schematic
As shown in the figure, usually a mobile communication system consists of a core network, a bearer network, an access network (base station), and a terminal.
2. 1G-5G communication evolution
The first generation mobile communication (1G) began around 1980 and is mainly used to simulate voice cellular telephone communication. There are many communication standards, but there are two main mainstream communication systems: AMPS (Advanced Mobile Phone System) and TACS (Total Access Communications System). The 1G base station is called Base Station (BS for short), and the terminal is an analog mobile phone (commonly known as Big Brother). The schematic diagram of the first generation of mobile communication (1G) is as follows:
First generation of mobile communication (1G) schematic diagram
The second and third generation mobile communication (2G/3G) mainly adopts the CS digital circuit switching scheme. The full name of the 2G base station is Base Transceiver Station (BTS for short), that is, the base station transceiver, and the 3G base station is called NodeB. Among them, 2G is represented by GSM network and 3G is represented by UMTS network. The principles of the second and third generation mobile communications (2G/3G) are as follows:
Second and third generation mobile communications (2G/3G) schematic diagram
The fourth generation mobile communications (4G) has completely entered the era of data networks, that is, entering the era of full IP, adopting PS packet switching technology, and no longer using traditional CS circuit switching technology. 4G base stations are called eNBs. VoLTE technology or CS FallBack technology is used in voice. The schematic diagram of the fourth generation mobile communication (4G) is as follows:
The schematic diagram of the fourth generation mobile communication (4G)
Specific description is as follows:
(1) In the early stage of 4G or when the 4G network coverage is not good, CS FallBack will fall back to the 2G/3G network for voice communication. (2) In the later stage of 4G network or when 4G network coverage is good, VoLTE is used to complete the carrying of voice services, which does not require 2G/3G network support at all. At the same time, the Internet service is also carried out through 4G LTE network.
The fifth generation mobile communication (5G) has the characteristics of high speed, low latency and large connection, and the 5G base station is called gNB. According to the investment cost, it is divided into non-independent networking (NSA) networking and independent networking (SA) solutions. The specific description is as follows:
4.1. Non-independent networking (NSA) architecture (taking Option 3X as an example)
Non-independent networking (NSA) architecture diagram
Non-independent networking (NSA) architecture description:
(1) The core network adopts 4G EPC, and on the basis of the existing 4G base stations, it deploys 5G base stations and promotes 5G terminals. Carry out 5G service.
(2) This solution is a transitional solution, and the advantage is that it has relatively little investment.
4.2. Independent (SA) networking architecture (taking Option 2 as an example)
Independent (SA) networking architecture diagram
Independent (SA) networking scheme description:
(1) In the case of good 5G network coverage, 5G terminals carry voice carrying through VoNR, as shown in the figure ① above.
(2) In the case of poor 5G network, it falls back to 4G VoLTE for voice bearing, as shown in the figure ② above.
(3) Without 5G and 4G networks, it falls back to the 2G/3G network for voice bearing, as shown in the figure ③ above.
3. Radio and Television 4G/5G network
Radio and Television 4G/5G network schematic
Specific description is as follows:
(1) According to public information, China Radio and Television 5G 700M base station was built by China Mobile.
(2) According to public information, China Radio and Television rents China Mobile 5G 2.6Ghz base stations and 4G network base stations, that is, China Radio and Television can rent China Mobile 5G and 4G networks to conduct business.
(3) According to public information, China Radio and Television has not yet seen China Mobile 2G and 3G networks rented.
(4) In this way, China Radio and Television will have 4G (actually China Mobile 4G network) and 5G (including 700Mhz, 2.6Ghz) networks.
4. Score
1. Regarding the shutdown of mobile network:
(1) 1G network shutdown: my country began to operate 1G business in November 1987, and 1G business was shut down by the end of December 2001. The duration is 14 years.
(2) Calls for shutting down 2G-3G network: With the advancement of 5G, my country's calls for shutting down 2G/3G networks are getting higher and higher. In addition, from the Communications World Report, it is expected that a total of 61 2G networks and 46 3G networks will be closed in 2025. Currently, the United States, Germany, Japan, South Korea and others have begun to shut down and withdraw the 2G/3G network.
2. Answers to fans’ questions
(1) The problem of using China Radio and Television Mobile Network on mobile phones is mainly the manufacturer’s adaptation and settings. If some mobile phones are not on the China Radio and Television List, they can also be used; some mobile phones can access the Internet, cannot make phone calls, etc. Through the above principle introduction, I think most people should have the answer, so I won’t expand it here.
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