1 Verizon Communications Verizon, USA
2 SBC Communication Southwest Bell Telecom Company, USA
3 American Quest Communications Company
4 AT& T USA
5 MCI microwave communication USA
6 sprint sprint America
7 BellSouth Nember USA
Comcast Comcast USA
Domestic telecom operators use American technology, and the technologies of three domestic operators:
1 Unicom WCDMA network is the most mature, and there are more than 130 commercial WCDMA networks in the world. European standards and patents are scattered, such as Qualcomm and Ericsson. They all hold patents, and the theoretical downlink rate is 7.2m/s. At present, 70% of the operators in the world are operating, mainly China Unicom and At & amp； T, Vodafone
Telecom CDMA 2000 network is the cheapest and smoothest upgrade scheme. The American standard, the upgraded version of CDMA 1X, is dominated by Qualcomm, and its theoretical downlink rate is 3. 1M/s or 9.3m/s. At present, there are 30% operators in the world, mainly including China Telecom, Verizon and KDDI.
Mobile TD-SCDMA network is the third generation mobile communication network independently developed by China. At present, only China Mobile is operating. The theoretical downlink rate is 2.8m/s.