Satellites are an essential part of the telecommunication system worldwide today. They can carry a large amount of data. satellite communication is a special use of microwave transmission systems. A Satellite is placed above the earth where its orbital speed exactly matches the Earth's rotation speed.  Hence it always stays over the same point with respect to the Earth.  In satellite communication, the earth station consists of a satellite dish that functions as an antenna and communication equipment to transmit and receive data from satellite overhead.

Advantages of Satellite Transmission

1. The area coverage through satellite transmission is quite large.

2. This is particularly useful for sparsely populated areas.

Disadvantages of Satellite Transmission

1. Placing the satellite into its Orbit involves a very high cost.
2. Transmission is affected by weather conditions like rain, thunderstorm, etc.

Microwave signals are used to transmit data without the use of cables. The microwave signals are similar to radio and television signals. Microwaves are used for long-distance communication. In microwave communication parabolic antennas are mounted on towers to send data to other antennas.

Advantages of Microwave

1. It offers ease of communication over difficult terrain.
2. Microwaves have the ability to communicate over oceans.

Disadvantages of Microwave

1. It is an insecure communication.
2. Its propagation is susceptible to weather effects like rains, thunderstorms, etc.
3. Implementation and maintenance cost is high.
4. Bandwidth is limited.

We are quite familiar with Radios and their working. Each radio signal uses a different frequency and this differentiates it from others. The transmitter takes some message, encodes it, and then transmit it with the radio wave. The receiver on the other end receives the radio waves and decodes it. Both the transmitter and receiver use antennas to radiate and capture the radio signal. Radio transmission is widely used by delivery services, policemen, security personals, etc.

Advantages of Radio Wave

1. It is easy to communicate through radio waves in difficult terrains since there is no need for any type of cable.
2. It can travel long distances in all directions. Also they can easily pass through obstacles like buildings so it can be used anywhere.

 Disadvantages of Radio Wave

1. Data Transmission is not secure.
2. The radio wave is susceptible to weather effects like rains, thunderstorms, etc.

Infrared is a type of unguided or wired transmission media. This is the frequency of light that is not visible to the human eye. Infrared light is widely used for short-range communication. The remote control is used in TV, VCR, Stereos, and other devices all use infrared communication.

Advantages of Infrared

1. It having short-range communication hence it is a secure mode of transmission.
2. It is quite an inexpensive transmission medium.

Disadvantages of Infrared

1. It can be only used in short-range transmission.
2. Infrared wave transmission cannot pass through obstruction like walls, buildings, etc.

Optical Fiber

A Fiber Optic cable is a light pipe that is used to carry a light beam from one place to another. Optical fiber consists of thin strands of glass-like material. The light sources used are either light-emitting diodes (LEDs) or Laser diodes (LDs). The Fiber Optic Cable consists of three pieces-

1. Core - The glass or plastic through which the light travels.
2. Cladding - Cover of the core that reflects light back to the core.
3. Coating - It protects the fiber cable from a hostile environment.

Types of Optical Fiber Cable

There are two types of Optical Fiber Cable.

1. Single-node: It supports a segment length of up to 2 km and bandwidth of up to 100 Mbps.
2. Multi-node: It supports a segment length of up to 100 km and bandwidth of up to 2 Gbps.

Advantages of Optical Fiber

1. It is immune to electrical and magnetic Interface.
2. It is guaranteed secure transmission and has a very high transmission capacity.
3. It can be used for broadband.

Disadvantages of Optical Fiber

1. It is difficult to install and maintain since they are quite fragile.
2. It is most expensive in all the cables.
3. Connecting two fiber cable together is a difficult process.

Transmission Media

Transmission media is a medium that carries a signal from one computer to another. It is also known as a communication channel. transmission media can be of two types:

1.  Guided Transmission Media (Wired Transmission Media)
2.  Unguided Transmission Media (Wireless Transmission Media)

Guided Transmission Media

This media physically connects the two or more computers. The data signal physically gets transferred from the source computer to the destination computer through the wired transmission medium.

Some of the Guided media are as follows: 

• Twisted pair cable
• Coaxial cable
• Optical Fiber

Unguided Transmission Media

Unguided or wireless transmission media transfer electromagnetic waves without using a physical conductor the signal is broadcasted through air or water.

Some of the Unguided media are as follows: 

• Infrared
• Radio Wave
• Microwave
• Satellite Link