What Is a Satellite Telephone?

Satellite phones are interphones that transmit information based on satellite communication systems, that is, satellite relay interphones. Satellite relay talker is the product of modern mobile communication, and its main function is to fill the area that cannot be covered by existing communication (wired communication, wireless communication) terminals, and provide more complete services for people's work. In modern communication, satellite communication cannot be replaced by other communication methods. All communication functions provided by existing commonly used communications have been applied in satellite communication.

satellite telephone

Satellite phone is based on

The characteristics of the high-orbit satellite (GEO) mobile communication service are derived from the use of 35800 above the equator

The satellite mobile communication service can provide two general services: one is a public satellite relay talker, and the other is a dedicated satellite relay talker. The former needs to interconnect the public exchange talker network to make a mobile call any one in the world. Fixed talker, which is performed only between a mobile station and its dispatcher. Both services can carry talker, paging and location information. These two services can also be combined to form unique communication capabilities. ^[2]

The first successful launch of the Soviet Union since October 4, 1957

The classification of satellite mobile communication systems can be divided according to their applications, or they can be divided according to the technical means they use.

Since the 1960s, humans have sent hundreds of communications and broadcasting satellites into high-orbit (GEO). These satellites have always played a leading role in achieving international long-distance communications and television transmission. However, there are some problems with high-orbit (GEO) satellites:

Satellite phone is too far from the earth

In free space, the signal strength of a square-high orbit (GEO) satellite that is inversely proportional to the transmission distance is too far away from the earth and requires a larger-diameter communication antenna.

Satellite phone signal delay

This delay can be noticeably uncomfortable when talking on the intercom. In data communications, latency limits the response speed. For a 2001 desktop supercomputer, a half-second delay meant that hundreds of millions of bytes of information were stuck in the buffer.

Satellite phone orbital resources are tight

There is only one high-orbit (GEO) satellite, and the interval between adjacent satellites must not be too small, because the ability of the earth station antenna to distinguish satellites is limited by the size of the antenna aperture. In Ka band (17 ~ 30GHz), in order to be able to separate satellites at 2 ° intervals, the reasonable size of the antenna diameter of the ground station should not be less than 66cm. Based on this calculation, GEO satellites can only provide 180 co-orbital positions. This also includes many of poor practical value, which are located above the ocean.