Theoretical basis and thinking of mobile phone signal

Mobile phone signal frequency range:   gsm900m:   890mhz-915mhz (upstream) 935mhz-960mhz (downlink) cdma800m:   825mhz-835mhz (upstream) 870mhz-880mhz (downstream)  dcs1800m:        1850mhz-1910mhz (upstream) 1930mhz-1990mhz (downlink)  pcs1900m:         1850mhz-1910mhz (upstream) 1930mhz-1990mhz The current mobile phone system is operating at a frequency of 800 to 1800MHz. It is important not to confuse this RF field with ionizing radiation, such as x-rays or gamma rays. Unlike ionizing radiation, RF fields do not cause ionization or radiation in the body. Based on this, the RF field is called a non-ionization field

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Buildings are now widely used in cast-in-situ, reinforcing mesh is indispensable, and in general, the spacing of rebar grids ranges from 10 centimeters to 20 centimeters. Non-cast floor slab, in the production is to be placed in the rebar, jerry-building only using a smaller or lower specifications of the rebar, the density of the reduction is very limited. It is generally believed that the metal plate can be isolated to electromagnetic waves, in accordance with the conventional, short wavelength electromagnetic wave penetration capacity over a long wavelength, but when the electromagnetic wave through the wall with rebar, statistics show that once reached the GHz magnitude of the electromagnetic wave, in the wall when the attenuation significantly increased, This is because the electromagnetic waves in the wall through the wall with the metal cage contact, there is a reflection phenomenon, and part of the wall continues to reflect and decay, the remaining through the wall of electromagnetic waves, the strength is not as strong as before. Second, what kind of toilet let WiFi not go in? In the bedroom, the living room can see the video smooth, feel the malice of the circle of friends, enjoy the pleasure of surfing, but in the toilet to release themselves, but deprived of the human survival of the WiFi signal, what is the impact of the home signal transmission? 1, rebar density buildings are now widely used in-situ, reinforcing steel mesh is indispensable, generally speaking, the spacing between the rebar mesh in 10 cm to 20 cm range. Non-cast floor slab, in the production is to be placed in the rebar, jerry-building only using a smaller or lower specifications of the rebar, the density of the reduction is very limited. If your home is so big, with all the thick steel, the WiFi signal won't be good! 2, the metal mesh is generally believed that the metal plate can be isolated on electromagnetic waves, in accordance with conventional, short wavelength electromagnetic wave penetration capacity over a long wavelength, but when the electromagnetic wave through the wall with rebar, statistics show that once reached the GHz magnitude of the electromagnetic wave, in the wall when the attenuation significantly increased, This is because the electromagnetic waves in the wall through the wall with the metal cage contact, there is a reflection phenomenon, and part of the wall continues to reflect and decay, the remaining through the wall of electromagnetic waves, the strength is not as strong as before. 3, wall material for WiFi, or other signals, not only rebar, even the concrete itself will have the function of shielding signal. The shielding performance is related to its thickness. The research proves that the dry wood is smaller than the gypsum board, the gypsum board is smaller than the concrete, and the concrete is less than the wall with the reinforcing steel. You can estimate, usually no reinforced concrete wall, home wireless router signal through once, the signal level is one times smaller, and then consider the distance and other factors, the room can cover the distance of 10 meters, three walls is basically the limit.

1. WiFi is at 2. 4G and 5G Band, reinforced concrete structure is seriously blocked, do not know whether to receive

Above "1Ghz above the wall is a significant increase in attenuation" disagree.

Because we use the FM radio, the band is generally in the 88-108mhz, the tunnel will be blocked.

There are, of course, solutions. See the Tunnel FM coverage (" broadcast station radio frequency optical signal transmission to the optical receiver through the optical cable, converted into an electrical signal input broadband base station, the 88mhz~108mhz FM band signal to stimulate the broadband amplification , output to the leakage cable/directional FM Transmitter antenna, The FM broadcast signal is transmitted wirelessly to realize the tunnel Broadcast FM coverage. ”）

But according to the principle of reinforcing bar barrier signal, it is necessary to complete the reinforcing bar net to reach the barrier effect. The net effect of the steel mesh collapsed during the earthquake should be greatly reduced.

Experiments are needed to verify the specific requirements.

2. How to tell the existence of a mobile phone

OSMOCOMBB (http://www.blogjava.net/baicker/archive/2013/11/13/406293.html) is a workaround.

　　

Theoretical basis and thinking of mobile phone signal