5 thoughts on “Why is there no signal on the mobile TV and mobile phone on the car after entering the tunnel?”
Toni
The mobile phone is communicated with microwave. The frequency range of mobile phone communication between my country is between 825 MHz and 2655 MHz (from 2G to 4G, the frequency gradually becomes higher). Called Divopo.
is a type of electromagnetic wave. When microwave encountering obstacles, there are two ways to pass, one is directly penetrated, but the energy of the microwave is too low and the penetration is poor; and the electromagnetic wave has a diffraction phenomenon. Therefore, the other method is to bypass Obstacles spread, But the wavelength of microwaves is relatively short, so the ability to shoot is relatively weak. At this point, this problem is easy to explain, because microwaves can not only penetrate the tunnel wall, but also cannot enter the tunnel by shooting around, so the mobile phone signal cannot be received in the tunnel. It, I do n’t know if you have noticed it. When you take the subway, you can still be full of tunnel signals in the underground. This is because there are distributed base stations and leaks in the subway to ensure communication. The special information service business (except for publishing, education, medical care); online data processing and transaction processing business in the first type of value -added telecommunications business, domestic Internet virtual special network business, and Internet data center business; The Internet access service business, call center business, information service business in the second type of value -added telecommunications business (excluding fixed network telephone information services and Internet information services);
Use the Internet to operate music entertainment products, game products operation, online game virtual currency distribution, art, performance drama (festival), anime (painting) products, engaged in Internet cultural product exhibitions, competition activities (online cultural business license valid November 21st);
In addition to the incomplete coverage of operators 'network infrastructure caused by some tunnels, excessive tunnels, and complicated environmental reasons, there are other reasons for the incomplete coverage of operators' network infrastructure construction. First of all, electromagnetic waves are transmitted in a straight line, and obstacles will not be bypassed. If you encounter obstacles that hinder electromagnetic wave transmission during the spread, the signal will be seriously affected. When the train passes through the tunnel, the tunnel wall will cause more serious obstructions to the electromagnetic wave. Secondly, when the mobile phone and the base station are relatively high -speed exercise, the cumulative Doppler frequent deviation will increase significantly, resulting in the difference in voice signals. Therefore, when the train passes through the tunnel, the mobile phone signal always becomes significantly worse.
The mobile phone is communicated with microwave. The frequency range of mobile phone communication between my country is between 825 MHz and 2655 MHz (from 2G to 4G, the frequency gradually becomes higher). Called Divopo.
is a type of electromagnetic wave. When microwave encountering obstacles, there are two ways to pass, one is directly penetrated, but the energy of the microwave is too low and the penetration is poor; and the electromagnetic wave has a diffraction phenomenon. Therefore, the other method is to bypass Obstacles spread,
But the wavelength of microwaves is relatively short, so the ability to shoot is relatively weak. At this point, this problem is easy to explain, because microwaves can not only penetrate the tunnel wall, but also cannot enter the tunnel by shooting around, so the mobile phone signal cannot be received in the tunnel.
It, I do n’t know if you have noticed it. When you take the subway, you can still be full of tunnel signals in the underground. This is because there are distributed base stations and leaks in the subway to ensure communication.
The special information service business (except for publishing, education, medical care); online data processing and transaction processing business in the first type of value -added telecommunications business, domestic Internet virtual special network business, and Internet data center business;
The Internet access service business, call center business, information service business in the second type of value -added telecommunications business (excluding fixed network telephone information services and Internet information services);
Use the Internet to operate music entertainment products, game products operation, online game virtual currency distribution, art, performance drama (festival), anime (painting) products, engaged in Internet cultural product exhibitions, competition activities (online cultural business license valid November 21st);
In addition to the incomplete coverage of operators 'network infrastructure caused by some tunnels, excessive tunnels, and complicated environmental reasons, there are other reasons for the incomplete coverage of operators' network infrastructure construction. First of all, electromagnetic waves are transmitted in a straight line, and obstacles will not be bypassed. If you encounter obstacles that hinder electromagnetic wave transmission during the spread, the signal will be seriously affected. When the train passes through the tunnel, the tunnel wall will cause more serious obstructions to the electromagnetic wave. Secondly, when the mobile phone and the base station are relatively high -speed exercise, the cumulative Doppler frequent deviation will increase significantly, resulting in the difference in voice signals. Therefore, when the train passes through the tunnel, the mobile phone signal always becomes significantly worse.
That's because the tunnel will block mobile phones and computer signals
After entering the tunnel, the mobile phone signal and WiFi were blocked and could not be used.
Because the signal in the tunnel will be blocked