From analog to GSM, from GSM to GPRS and so on, the invention of every new technology has greatly promoted the development of mobile phones.
The development history of mobile phones can be roughly divided into these generations:
The first generation (1G)
The second generation (2G)
Third Generation (3G)
The first generation of mobile phones (1g)-analog mobile phones were born in the late 1970s.
Analog mobile phone system mainly adopts analog and frequency division multiple access (FDMA) technologies.
AMPS (North American Cellular System), NMT (Nordic Mobile Phone) and TACS (Omni-directional Communication System) are the main analog standards.
Only voice communication can be carried out, the receiving effect and confidentiality are insufficient, and the wireless bandwidth is not fully utilized.
The greatest achievement of the first generation wireless network technology is to remove the user line connecting the telephone and the network, so that users can receive and make calls wirelessly anywhere.
The second generation (2G)
At present, the most widely used mobile phones in the world are GSM mobile phones, CDMA mobile phones and PHS mobile phones, collectively referred to as the second generation mobile phones (2G).
The second generation system introduced digital radio technology, which provided higher network capacity, improved voice quality and confidentiality, and also introduced seamless international roaming.
Besides voice communication, the second generation system can also send and receive short messages (SMS), multimedia messages (MMS) and WAP.
At present, the market labels of the second generation mobile phones in the world are GSM, D-AMPS, PDC and IS-95 CDMA.
Third Generation (3G)
The third generation mobile system IMT-2000 is a broadband multimedia system, which can provide high-quality broadband integrated services.
The main goal of the third generation mobile phone is to develop a universal wireless communication system, but as a result, many different formats have emerged, including WCDMA, CDMA2000 and TD-SCDMA.
These new standards are based on CDMA (code division multiple access) technology, and have further developed in bandwidth utilization and data communication.