Can I send a text message if my mobile phone has no signal?

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.

I can't send text messages without a signal on my cell phone. If there is a WiFi signal, you can post information on social platforms such as WeChat and QQ, and Apple phones can send IMessage. In the traditional sense, short messages are sent through the mobile network of service operators, so there must be a signal from the operators. QQ, WeChat and IMessage are all sent through data networks, which can be mobile networks of service operators or Wlan networks provided by other operators.

signal

A signal is a physical quantity representing information. For example, electrical signals can represent different information through changes in amplitude, frequency and phase. This kind of electric signal can be divided into analog signal and digital signal. Signals are tools and carriers of information. Broadly speaking, it includes optical signals, acoustic signals and electrical signals.

The reason why the mobile phone has no signal

1, SIM card problem.

The first possibility is that our mobile phone is not compatible with the SIM card inserted in the mobile phone, or has poor contact with the SIM card. At this time, the mobile phone will display that the SIM card is invalid, and you can find that the mobile phone has no signal.

2. The location is too far from the signal base station.

The second possibility is that the signal base station near our location is too far away, such as mountains, oceans, forests and other areas, and we can't receive the signals sent by the base station.

3. Signal shielding is placed around the site.

The third possibility is that there is signal shielding where we use mobile phones, such as the examination room where we are taking exams. At this time, our cell phone signal will be blocked.

4. The mobile phone has turned on the flight mode.

The fourth possibility is that we accidentally turned on the phone, turned on the phone settings and turned off the flight mode in flight mode.