History of satellite communication and its applications.

Tina Forbes — Mon, 09 May 2016 12:09:00 +0000

At the end of 1945 the world saw a small scientific article, which was devoted to the theoretical possibilities of improving communication (primarily the distance between the receiver and the transmitter) by raising the antenna to the maximum height.

The author of the article “Extraterrestrial Repeaters” was the English scientist Arthur Clarke. This marked the beginning of the development of a new type of communication.

What was the principle of operation?
It was quite simple – the scientist proposed that a large repeater antenna, which would receive signals from a terrestrial source and transmit them further, should be placed in orbit around the Earth.

The main advantage was the huge coverage area, which could be controlled by just one satellite. This would have significantly increased the quality of the signal, removed the limit on the number of receiving stations and would not have required additional construction of terrestrial repeaters. The United States became interested in the project as part of a solution to the problems with transatlantic telephone communications.

The development of satellite communications systems began with the launch of the first Echo-1 (a passive repeater in the form of a metallized ball) into space in August 1960.

Later, key satellite communications standards (operating frequency bands) were developed, which are widely used all over the world.
Satellite communications applications

Since its successful implementation, the quality of satellite communications has increased significantly.

Thanks to the introduction of mobile ground stations the subscriber could receive the radio signal irrespective of the satellite location at any time of the day, automatically switching from one coverage area to another and connecting to the nearest repeater in automatic mode.

The use of satellite communications can be divided into several conditional areas:
Backbone communication. Initially there was a task to transfer a big volume of information (voice messages in particular), but with time, with the transition to digital format, such need disappeared and today from this area satellite communications replace fiber-optic networks;

VSAT. The so-called “small” systems with an antenna diameter of up to 2.4 meters. The technology is successfully developing, and serves to create private communication channels;

mobile communications (the basis of telephony and television broadcasting);

Internet access.

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History of satellite systems

Tina Forbes — Fri, 18 Mar 2016 13:36:00 +0000

The first artificial satellite was launched in 1957. The satellite was a metal ball, 58.5 cm in diameter. On one side protruded four oblong antennas. The signals it transmitted could be received even by amateur radio operators.
This launch marked the beginning of the Space Race and began the development of satellite systems.
Early communications satellites worked in passive mode – they simply reflected the signal from the source, to the receiver.
The final signal was quite weak because most of the energy was lost.
Passive transmission was replaced by satellites with active transmission. Unlike their predecessors, they amplify the received signal before sending. The first satellite with active transmission was Project SCORE. It operated for eight hours, broadcasting U.S. President Eisenhower’s Christmas speech.
As progress was made, the future of satellite systems became increasingly clear. In particular, commercial applications were becoming possible.
In 1962 the first commercial communications satellite, Telstar 1, built by Bell Labs, was launched. This satellite was able to transmit a television signal across the Atlantic Ocean.
In the 1960s, satellites were mostly launched into medium or low earth orbit. The satellites had a high orbital velocity and as a result were not observed from one point on Earth for long periods of time. Instead, they would fly across the sky and disappear from view.
This behavior caused service interruptions, and any satellite system needed a large enough number of satellites to maintain stable communications. Geosynchronous satellites could solve the problems. Such satellites stayed at one point for the observer and did not interrupt the signal.
Syncom 3 was the first geosynchronous satellite. It was launched in 1964 and was used to transmit live broadcasts of the Olympic Games in Japan for the United States.
The success of using satellites for radio and television did not go unnoticed. In the mid-1970s, the first commercial satellite telephone systems began to appear.
Initially, they were developed as a replacement for GSM devices, which at the time were expensive and cumbersome.
By the time the first commercial telephone network was launched, GRPS networks had managed to evolve and come a long way. They became cheap and were well distributed.
Today, satellite communications are most commonly used in the military, maritime and aviation industries. Of particular value is the use in remote areas and areas affected by natural disasters.
As of January 1, 2021, there are 2,224 satellites orbiting the Earth.

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History of satellite communication and its applications.

History of satellite systems