Can you answer the phone and receive text messages in the mountains?

Not necessarily. It depends on where the mountain is and the surrounding terrain.

Cell phone signals propagate in the air in the form of electromagnetic waves. When a mobile phone makes a call, it will convert the sound into a signal. How to send it to the nearest base station A in the form of electromagnetic waves? After receiving the signal, the base station A will forward it to the base station B covering the other party's mobile phone signal through the switch, and the base station B will send the signal to the other party's mobile phone. After receiving the signal, the mobile phone will convert the signal into voice, thus realizing two-way communication.

This signal travels in a straight line and will be blocked when it meets a tall building, so the base stations (signal towers) we see every day are erect and very high. The frequency of our mobile phone signal is generally around 900Mhz. In addition to ionospheric reflection, mobile phone signals also propagate through electromagnetic waves or radio waves. The service range of each base station is limited, and the signal will gradually weaken with the increase of distance. If you happen to be on the edge of a base station's service range, the signal will be relatively weak at this time. When the mobile phone signal propagates in a straight line, it will have a serious impact on the signal when it encounters obstacles that hinder the propagation of electromagnetic waves.