First, let’s introduce the network classification of China’s three major operators: China Mobile’s 2G network is GSM, 3G network is TD-SCDMA, China Unicom’s 2G network is GSM, 3G network is WCDMA, China Telecom There is only 3G network, which is CDMA2000. If your 3G mobile phone has WCDMA and GSM, it must be from China Unicom. Hope my answer is helpful to you!