1.GSM is the network standard of the second generation mobile communication technology, which is what we usually call 2G. Another common 2G standard is CDMA, led by Qualcomm. Most patents of GSM are in the hands of Europeans (Ericsson, Nokia, Siemens and other European companies), and it is the leading 2G standard in Europe. At present, GSM users account for more than 85% of 2G users, and GSM networks have been deployed in more than 80 countries and regions around the world. GSM is worthy of the name (GSM is an abbreviation in English, translated into Global System for Mobile Communications in Chinese). The GSM camp can completely suppress or even defeat the CDMA camp.
GSM later developed wireless data transmission and realized the service of connecting to the Internet, namely GPRS (commonly known as 2.5G) and EDGE (commonly known as 2.75G).
2.WCDMA is the third band mobile communication network standard, which is frequency division duplex. Belongs to the GSM camp. Most of the special trains are in the hands of Europeans (Ericsson, Nokia, Siemens, etc. ), some patents are in Qualcomm and some Japanese companies. Huawei in China also owns 5% of the basic patents. WCDMA was born to fight against CDMA2000 in GSM camp. WCDMA has greatly enhanced EDGE's ability to transmit data, providing an uplink rate of up to 384Kbps and a downlink rate of up to 2Mbps. After upgrading to HSPA, the uplink and downlink can be upgraded to the highest theoretical 5.76Mbps to 14.4Mbps. At present, WCDMA has more than 2,000 mobile phones and network card terminals, and more than 200 operators in more than 0/00 countries around the world operate WCDMA networks, with more than 500 million global users, accounting for more than 70% of global 3G users! And it has good compatibility with GSM system, and will be upgraded to LTE (WCDMA-HSDPA-Hsupa-HspA+-FDD LTE) with clear routing in the future.
3.TD-SCDMA is also the third generation mobile communication system. Because there are some patents in China (Datang in China has a patent of 17%), it is strongly supported by our government. The system is in time division duplex mode. Compared with WCDMA, it has few advantages, such as fewer terminals, fewer users, slow network speed, less GSM compatibility and fewer international supporters. Only China is used in the world, and TD lags far behind WCDMA in 3G family. TD can hardly catch up with WCDMA in 3G era, but it can shorten the distance in quasi-4G LTE era. At present, TD camp has been seeking the complementarity of TDD-LTE and FDD-LTE * * stations. Although most operators will only build FDD-LTE single-frequency base stations in the future, some foreign operators are still interested in FDD-LTE and TDD-LTE. Although the number of supported operators is small, it can be regarded as going international!
Finally, talk about the 2G and 3G systems of the three major operators in China.
Mobile -2g: GSM/GPRS/edge, 3g: TD-SCDMA/TD-HSDPA.
Unicom -2g: GSM/GPRS/edge, 3g: WCDMA/HSDPA/hsupa.
Telecom -CDMA IS95/CDMA 1x, 3G: CDMA 2000 EV-DORev. O/A/B
I hope you are satisfied with my answer. Thank you!