Why is there a delay in receiving SMS by mobile phone?

1. SMS memory overflow. After the short message storage of the mobile phone terminal is full, it can't receive the short message normally, and there will be a delay in sending the short message after clearing the short message space. After repeated forwarding in the SMS center, the mobile phone is still in the state of memory overflow, which will cause the delay of receiving SMS to exceed 1 hour.

2. The mobile phone is turned off and not in service area. Due to wireless reasons, coverage reasons and mobile phone reasons, the network cannot page users when sending short messages. In this case, the SMS center needs to send SMS through SMS forwarding mechanism. If the mobile phone is still not in the service area after repeated forwarding by the SMS center, the SMS reception delay will exceed 1 hour.

3. Network problems, such as HLR and MSC, and short message center, will also cause short messages not to be received.