Why is there only 3g network in Lhasa, and it's unstable, so mobile phones can't work?

The signal will be affected by various factors such as topography, landforms and tall buildings. If your location is relatively closed, the signal will be affected.

You can restart your mobile phone, or change your mobile phone card to that of your family and friends and try again to see if the signals of other Unicom users around you are normal.

If your signal problem has not been solved, please contact the customer service in your hometown for consultation.