ZTE u880 can't send short messages.

I have encountered all the problems mentioned by the landlord. I can't send text messages, sometimes I can't make phone calls. Because my phone was prepaid, I went to China Mobile Business Office. China Mobile has someone to help me solve it. Home-Settings-Wireless and Internet-Monternet. Change the original 3G priority to GSM only. Problem solved. Now the effect is very good. The main reason is that ZTE U880 can use the GSM card of China Mobile to directly use the 3G(TD-SCDMA) network (both are the networks of China Mobile). This will happen when there is a dispute between networks, unless the 3G signal is very strong where you are, and the 3G transmission tower is near you. We use GSM card for the time being (3G card is still immature), so setting that card as GSM can solve the problem. The problem of buying a V880 upstairs has been solved. Of course, because the V880 is the custom machine of China Unicom, it only supports China Unicom's 3G(WCDMA) and does not support mobile 3G(TD-SCDMA), so there will be no network competition. Of course it has been solved.