What is the principle of SMS receiving prompt?

The principle of SMS receiving prompt is as follows:

The control channel provides access to SMS messages. When a friend sends a short message to the receiver, the message will first pass through SMSC (Short Message Service Center) in the form of a small data packet on the control channel, then pass through the cell phone tower, and then the cell phone tower will send the message to the mobile phone. Similarly, when the receiver sends a short message, the mobile phone will send the short message to the transmission tower through the control channel, and then transmit it from the transmission tower to SMSC, and finally reach the receiving target from this position. The actual data format of SMS includes length, timestamp, target phone number and SMS format.

Short message is the earliest short message service and the most popular short message service at present. At present, the length of this short message is limited to 140 bytes, which can be text. Short message is welcomed by the public because of its simple and convenient use function, but it always belongs to the first generation wireless data service, and there are technical standards restrictions on its content and application.