The signal is blocked. Can you get the message? QQ or Fetion can be obtained.

Of course, if the signal is blocked, it will not be received. If there is no signal, your QQ Fetion is offline on the server and will be saved as an offline message. As for SMS, the operator will send you a SMS. If your mobile phone has no signal, it will return a status report to the operator, so the gateway will resend it regularly until a successful status report is released. This should be the reason for the construction. Generally, it's like an elevator, surrounded by metal, and of course the signal is not good.