2G:CDMA

3G:CDMA2000

4G:FDD LTE，TD-LTE

Tip: 2G: Technical specification for the second generation mobile phone communication, with digital voice transmission technology as the core. Generally defined as not being able to directly transmit e-mail, software, etc. Only the technical specifications of mobile phone communication are available with calls and some transmissions such as time and date.

3G: The third generation mobile communication technology refers to the cellular mobile communication technology that supports high-speed data transmission. 3G services can transmit voice and data information at the same time, and the rate is generally above several hundred kbps. 3G refers to a new generation of mobile communication system that combines wireless communication with multimedia communication such as the Internet. 3G has three standards: CDMA2000, WCDMA and TD-SCDMA.

4G: the fourth generation mobile communication technology, foreign abbreviation: 4G. This technology includes TD-LTE and FDD-LTE (strictly speaking, although LTE is promoted as a 4G wireless standard, it is not actually recognized by 3GPP as the next generation wireless communication standard IMT-Advanced described by the International Telecommunication Union, so it has not reached the 4G standard in the strict sense. Only the upgraded LTE Advanced can meet the requirements of the International Telecommunication Union for 4G). 4G combines 3G and WLAN, which can transmit data, high quality, audio, video and images quickly. The download speed of 4G can reach more than 100Mbps, which is 25 times faster than ordinary home broadband ADSL(4 megabytes), and can meet the requirements of almost all users for wireless services.