Traditionally, the first generation cellular mobile communication system was 1978, and Bell Laboratories developed the Advanced Mobile Phone Service (AMPS) system.

With regard to 3G, there are three international standards, namely CDMA2000 derived from CDMA 1X (for domestic telecommunications), WCDMA developed by GSM (for China Unicom) and TD-CDMA developed by China itself (for China Mobile).

At present, many countries have entered the commercial phase of 4G, and it is expected that 5G will enter the commercial phase after the corresponding standards mature in 2020.