What is satellite phone

Satellite telephone is a communication system that uses artificial satellite as a communication platform, uses ground base station as a relay channel, amplifies the voice signal through the repeater of the earth station, and forwards it directly to the user through the repeater.
Unlike terrestrial mobile networks, it uses artificial earth satellites as communication satellites.
The satellite has two orbital planes, 9600 kilometers apart.
There are two satellites in the same direction in each orbit plane.
Either of the two orbital planes is a plane of circular motion, and no point can be on the two circles at the same time.
Using this principle and method, people can choose and determine the position of the earth station at different times.
When the position of the earth station changes at a certain time point, the signal waveform related to this will be generated.
This signal waveform is called carrier curve.
The carrier curve can be used for digital communication.
Satellite communication system includes signal generation, transmission, reception, decoding and signal control.
The signal transmission part is composed of ground base station and satellite repeater, which is mainly used for signal transmission with ground station. Satellite communication has been widely used in the world. Since 1980, the United States has been using geostationary orbit satellites as communication satellites for communication.
China joined the international organization in 1984 and began to use the international standard geosynchronous orbit communication satellite network in 1986.
The United States began to use C-band transmission on the Asia-Pacific 1 communication satellite in 1989. In 1990, the United States applied E-band transponders on the World 4 communication satellite. In 1992, the United States began to use C-band transponders on the Asia-Pacific 2 communication satellite. At present, more than 10 transponders have been used for two-way communication between China and the United States.