Communications Satellite from A to Z
Communications Satellite
Based on the type of work, satellites are divided into communication satellites, navigation satellites, weather measuring satellites, earth observation satellites, scientific satellites and military satellites.In this article, we will learn about the progress of the use of all these satellites in our lives. The satellite that we will learn about in detail today is the Communication Satellite.Communication satellites have a huge impact on our daily lives. The use of TV, telephone, internet, etc., which we think is essential for our lives today, has all been made possible by the invention of this communication satellite technology. All of these are electronic birds (satellites are often referred to as electronic birds). Rotating around the world has bound the whole world in a tight bond and turned the whole world into a Global Village.
The main areas of use of communication satellites include services such as TV broadcasting, the process of receiving and transmitting telephone conversations, and data communication. In all of these cases satellites or artificial satellites act as a repeater station that maintains communication through point-to-point, point-to-multipoint or multipoint connections. In this case, the satellite first transmits a certain quality signal from the ground station known as the up link signal, the satellite translates this signal to a lower quality frequency signal (also known as the down link frequency) and amplifies it to another ground earth station or Returns to a station located on the ground.
The difference between the up link frequency and the down link frequency is kept so that there is no difference between the signal sent from the ground and the signal returning to the ground via satellite. Normal air pressure low frequency propagation loss is much less. That is why the down link frequency (frequency) is kept lower than the up link frequency in order to keep the propagation loss low due to the power limitation of the satellite.
The equipment used in communication satellites is basically a transponder which acts as a receiver, amplifier and transmitter. Satellite communications typically use the bandwidth frequencies c, x, ku and ka. ka bandwidth has recently been set for satellites. The c bandwidth of 6 GHz up-link frequency and 4 GHz down link frequency is very popular and is commonly used for broadcasting TV shows and telephone services within the country and internationally. The x band is commonly used for government and military satellite communications.
The band with a frequency of 14/11 GHz is commonly used in domestic work. Also, when the c and ku bands are fully filled, the ka band with 30/20 GHz uplink and downlink frequency is used for multimedia and broadband.
There are a number of advantages to using satellites over terrestrial networks. One of the advantages of this is that it is possible to communicate with a wide area using satellite. Mobile wireless communication is possible anywhere, bandwidth is available in many lengths.
Point-to-point satellite connections are commonly used for telephone circuits. At present, about 80 percent of international telephone connections are accessed via satellite. The main advantage of using satellite in communication is that it provides point-to-point and multipoint interactive connectivity, meaning that multiple users can communicate simultaneously with one source via satellite.
The success of satellite technology
Although the basic concept of global communication was founded in 1945 based on the Viocin Conas satellite, it took almost two decades for this concept to become a reality. On June 26, 1985, the International Telecommunication Satellite Agency sent a satellite named INTELSAT-1. Known as the Early Bird, it was the first geostationary communication satellite to be launched from Earth. It had a capacity of 240 circuits.
Then in 1993 a satellite named INTELSAT-7 with 27 channel C-band and 10 channel ku band transponder was sent. The satellite could simultaneously broadcast 16,000 telephone calls and three color TV programs, or 90,000 telephone circuit services with the help of digital circuit multiplication equipment (DCME). The latest addition to the INTELSAT series is the INTELSAT-8, which has 36 C-band and six ku-band transponders. This satellite can simultaneously broadcast 22,000 telephone calls and three color TV programs or simultaneously provide services on 112,500 telephone circuits with the help of DCME.
In addition to the INTELSAT series, several other types of communication satellites are sent under the name INSAT series. The first satellite in the series, known as INSAT-1, had only three transponders in 1983. The satellite, launched at the same time in this series, has 35 transponders that cover all bandwidth. This satellite is known as INSAT-3c which was launched in 1992.
Regional Satellite
INTELSAT series satellites typically provide services over a large area. But it is not very useful for internal communication of their respective countries. This led to the need for regional satellites for internal communication. In 1973, the European Space Agency launched a satellite known as EUTELSAT to increase regional communications. Other regional satellites include ANIK launched by Canada, Molniya launched by Russia, PALAPA launched by Indonesia, INSAT launched by India and Japan Communication Satellite (CS) launched by Japan. However, it is very sad that our country does not have its own satellite. For internal communication we are still completely dependent on microwave communication and for international communication we rely on various international satellites sent by other countries.
In addition to international and regional satellites, various types of non-GEO satellite systems are used for communication. The Iridium Satellite System is one of the most advanced of these non-GEO systems. Iridium is a wireless telecommunication network based on satellites. The system was designed by engineers from Motorola's Satellite Communications Group to build a global wireless telecommunications network. In this system, 60 km of the earth's surface. There are 6 satellites in the area.
The Iridium project was shut down in 2001 due to losses. But now the system is being brought back to business.
When an Iridium technology telephone is activated, the satellite user located near the telephone is informed about the legitimacy and location through the Iridium network. The telephone call then travels from one satellite to another via satellite. Satellite and ground control are usually connected in bandwidth and telephone messages are transmitted to L-band.
