Wither invite!
The satellite enclothes global truly, but unmanned area does not have Tibet the formulation of signal is a mistake. What the satellite enclothes is satellitic signal, tibet unmanned area covers satellitic signal likewise, than can carrying a satellite like a few herdsman aerial can watch satellitic TV, even cocoa on the west in had debutted inside groove guard received Internet, but unmanned area of Tibet did not have a plenty of communication signal, it and satellitic signal are two different ideas. So, satellitic signal covers the whole world, and communication signal covers a range finite, in lack communication radical standing room, do not have mobile phone signal.
(the picture originates network)
Satellite, accurate should call orbiter, it is the mankind those who build is OK unmanned like what the earth or other planet surround to move like natural satellite spacecraft, science of in order to is explored, each domains such as astronomical observation, geological survey, weather forecast, military affairs, communication, navigation. General satellite signal is to use satellitic antenna to transmit signal the satellite to go up, classics satellite is received turn after frequency magnifies, in according to enclothe an area to blast off come down, for the ground the satellite receives a station or the user is received. Go up from theory for, satellitic signal can enclothe global any corner, incorporate satellitic communication signal.
(the picture originates network)
And signal of our mobile phone is to pass the ground is wireless signal is transmitted between communication radical station, namely that high shock that we often see in the city those who stand " signal box " , is not to carry a satellite. Wireless communication base station transmission space is limited, a paragraph of distance needs every other install, if be apart from too far, so communication signal is met very flabby calm. So, make sure mobile phone signal wants to build above all base station, but in unmanned area, because signs of human habitation is exiguous, demand of adversary machine signal is little, build base the cost of the station very tall, do not have so base the station is enclothed, also do not have mobile phone signal. It is unmanned area not merely actually, a few remote regions, do not have sometimes when mobile phone signal, because,also be around base the station is little, base the distance is far between the station cause.
(the picture originates network)
Above paragraphs mentions unmanned area enclothe satellitic communication signal, but the mobile phone that we use daily basically cannot receive satellitic communication signal, want to realize communication through the satellite, need to pass specific satellitic phone to receive. Communication of use satellite telephone is very costly, because general and daily life is not used, so satellitic phone does not gain ground, only division take an examination ofing, ocean is carried or do not have mobile phone signal but the place that needs communication just can be used. That is to say, if you are taking telephone call of a satellite, the unmanned area in Tibet also is euqally OK maintain what carry news report external.
(the picture originates network)
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