Joke Collection Website - Public benefit messages - What is the sending mechanism and principle of short messages?

What is the sending mechanism and principle of short messages?

Cell phone-base station-cell phone.

Usually, the message has been sent. It is the mobile phone that sends the text message, and it is not known whether the base station sent it successfully.

The short message sending report is the prompt given by the mobile phone to the user after the base station replies that the mobile phone has been sent successfully.