The three major operators refer to three companies that provide fixed telephone, mobile telephone and Internet access communication services, namely China Telecom, China Mobile and China Unicom. 1. China Telecom: It is a very large state-owned communication enterprise in China, mainly engaged in integrated information services such as fixed telephone, mobile communication, satellite communication and Internet access.

Demonstration model: iPhone12&; & Huawei P40 &；; & Xiaomi 1 1 system version: IOs14.4&; & ampemui 1 1 & amp； & miui12.0.7 The three major operators refer to three companies that provide fixed telephone, mobile telephone and Internet access communication services, namely China Telecom, China Mobile and China Unicom.

1. China Telecom: It is a very large state-owned communication enterprise in China, mainly engaged in integrated information services such as fixed telephone, mobile communication, satellite communication and Internet access.

2. China Mobile: It is a mobile communication operator based on GSM, TDD-LTE and FDD-LTE standard networks, mainly engaged in mobile voice, data, broadband, IP phone and multimedia services, and has the right to operate the international networking unit of computer Internet and the right to operate international entrances and exits.

3. China Unicom: formed by the merger of the former China Netcom and the former China Unicom, mainly engaged in GSM, WCDMA and FDD-LTE mobile network services, fixed communication services, domestic and international communication facilities services, satellite international private line services, data communication services, network access services and various telecom value-added services, as well as system integration services related to communication information services.