Satellite communication refers to the system where we transport information from one place to another through the use of a communication satellite in orbit around the Earth. To help you understand it better, think of it like how easily you can watch the English Premier League on your television. Satellite communication has made this possible. Thus, we will take a look at the meaning of this and explore the functions, advantages, and types for a better understanding.
Introduction to Satellite Communication
A communication satellite is an artificial satellite which is responsible for transmitting the signal through a transponder as it creates a channel between the transmitter and the receiver situated at different locations on the Earth.
Telephone, radio, television, internet, and military applications make use of satellite communications. It might sound hard to believe but more than 2000 artificial satellites hurtle around in space right now above your heads as you read this article.
Working Of Satellite Communications Work
The communication satellites are alike the space mirrors that assist us to bounce the signals like radio, internet data, and television from one side of the planet to another. It involves three stages which can help explain the working, they are:
Let’s take a look at an example of signals from a television. In the first stage, the signal from the television broadcast on the earth’s other side is first beamed up to the satellite from the ground station on the earth. We refer to this process as uplink.
The second stage consists of transponders like radio receivers, amplifiers, and transmitters. We use these transponders to boost the incoming signal and for changing their frequency. This helps in the outgoing signals not being altered. The transponders vary depending on the incoming signal sources.
Finally, the third stage comprises a downlink in which it sends the data to the other end of the receiver on the earth. It is imperative to understand that generally there is one uplink and numerous downlinks.
Need for Satellite Communication
You know by now that there are diverse ways of communicating and the propagation of these waves can occur in different ways. The two ways in which communication took place for a particular distance are ground wave propagation and skywave propagation. The maximum distance which they cover is 1500 km and this was overcome as we introduced satellite communication.
Satellite Communications in India
Interestingly, one of the largest domestic communication systems which are situated in the geo-stational orbit is the Indian National Satellite (INSAT) system. In the INSTA system, we have around more than 200 transponders which we use for multiple purposes.
It includes telecommunications, weather forecasting, television broadcasting, disaster warning, search and rescue operations, and satellite newsgathering. Many satellites have been launched from 2002 till 2020. The first one was KALPANA-1 in 2002 mean for communication and climate & environment. On January 2020, GSAT-30 was launched for the purpose of communication.
Applications of Satellite Communication
There are quite a lot of applications for which we use it. It includes the following:
- Digital cinema
- Internet access
- Radio broadcasting
- Disaster Management
- Amateur radio
Advantages of Satellite Communication
There are various advantages which we will study in detail. Firstly, it makes the instalments of circuits easy. Secondly, the elasticity of these circuits is incredible. Thirdly, through its help, we are able to cover every nook and corner of our planet. Finally, the entire control of the network is in the hand of the user.
Disadvantages of Satellite Communication
Along with the advantages, there are also disadvantages like the initial expenditure is quite expensive. After that, there are also many chances of the frequencies being blocked. Finally, there is also propagation and interference.
Passive and Active Satellites
Satellite communication makes use of two kinds of artificial satellites for transmitting the signals. They are passive and active satellites.
If we put a hydrogen balloon with a metallic coating over it, up in the air, it technically turns into a passive satellite. This kind of balloon can reflect microwaves signals from one place to the other. Similarly, passive satellites in space are the same. These satellites just reflect the signal back towards the Earth without amplification.
Active Satellites, contrasting passive satellites, intensify the transmitted signals before re-transmitting it back to Earth. It guarantees exceptional signal strength. Passive satellites were the earliest communication satellite but now about all the new ones are active satellites.
Satellite Communication Services
We can classify the satellite communication services into two categories which are:
One-way satellite communication
Two- way satellite communication
One-way satellite communication
In this satellite communication, the communication generally occurs between either one or numerous earth stations via the help of a satellite. Moreover, the communication occurs between the transmitter on the first earth satellite to the receiver which is the second earth satellite. Further, the transmission of the signal is unidirectional. Some of the most common one-way satellite communication is:
- Position location services are offered by the radio
- A part of space operations services is tracking
- Internet services come about with broadcasting satellites
Two-way Satellite Communication
In this communication, it exchanges the information between any two earth stations. In other words, there is a point to point connectivity. The signal transmits from the first earth station to the second earth station such that there are two uplinks and two downlinks occurring between the earth stations and the satellite.
FAQ on Satellite Communication
Question 1: What are the advantages of Satellite Communication?
Answer 1: Firstly, it makes the instalments of circuits easy. Secondly, the elasticity of these circuits is incredible. Thirdly, through its help, we are able to cover every nook and corner of our planet. Finally, the entire control of the network is in the hand of the user.
Question 2: What are the active satellites?
Answer 2: Active Satellites, contrasting passive satellites, intensify the transmitted signals before re-transmitting it back to Earth. It guarantees exceptional signal strength. Passive satellites were the earliest communication satellite but now about all the new ones are active satellites.