How does Apple X intercept all phone calls and text messages in a period of time?

After the phone is turned on in Do Not Disturb mode, all calls and text messages can't come in.

Short message is text or digital information sent or received directly by users through mobile phones or other telecommunication terminals. The number of characters that users can send and receive SMS at a time is 160 English or numeric characters or 70 Chinese characters. The inventor of mobile phone short message is Finnish. Because Nordic people are sensitive and don't like to express by phone, they invented short message on a whim. Some people on the Internet say that the inventor of SMS is Marty Cooper, an American who works for Motorola, but he invented the mobile phone, not SMS.