What does 3g network Unicom 2g mobile 2g mean?

GSM Chinese is a global mobile communication system and a digital mobile phone network standard formulated in Europe. GSM adopts digital modulation technology, and one of its key technologies is TDMA (each user occupies frequency load in a certain time slot and can only receive information at a specific time). The GSM system includes GSM 900:900MHz, GSM 1800: 1800 MHz, GSM- 1900MHz and GSM- 1900 MHz. In more than 159 countries around the world, we can get the same quality telephone service without barriers. Unicom 2G/ mobile 2G(GSM) usually means that the mobile phone system supports the use of Unicom 2G network and mobile 2G network. If you still can't solve the problem, you can contact mobile phone customer service to find out.