China Unicom reminds you that the number you dialed is power off or out of service, and then shows that the user is busy. What happened?

1, because the other party is turned off, the prompt is turned off;

2. It is suggested that the out-of-service area may be due to poor signal. Electromagnetic waves will be affected by various factors such as topography, landforms, tall buildings, climate, etc., so that only weak signals can be received in a certain range, such as the basement, first floor and second floor of some floors. This is a very normal phenomenon. As an operator, we attach great importance to network construction and have been constantly strengthening the breadth and depth of network signal coverage. Because network coverage will be affected by many factors, we will strive to speed up the pace of network construction and continuously improve the network coverage area. We look forward to your continued attention and supervision. Thank you!

3. Remind users that they are busy, usually because the other party is on the phone or the other party refuses to answer your phone.