UnGuided Transmission Media

UnGuided/Wireless Transmission Media transfer electromagnetic waves without using a physical medium or conductor. It is also referred to as Unbounded or Wireless transmission media.

Advantages of unguided media

1. The signal is broadcasted through free space (air).
2. Unguided signals can travel in several ways: sky propagation, ground propagation,  and line-of-sight propagation.
3. The electromagnetic spectrum, ranging from 3 kHz to 900 THz, used for wireless communication.

Types of unguided/wireless transmission media

There are 3 types of unguided/wireless transmission media which are Radio Waves, Microwaves, Infrared are mentioned below.

Radio Waves Definition

Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Electromagnetic waves from frequencies between 3 kHz and 1 GHz.

Advantages of Radio Waves

1. Radio waves are omnidirectional (propagated in all directions).
2. It can penetrate walls.

Radio Waves Uses

• Mostly used for wide area networks and mobile cellular phones
• Radio waves uses for multicasting (one to many)

Radio Waves Examples

• Television
• FM radio

Microwaves Definition

Microwaves are a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter. Electromagnetic waves from frequencies between 1 GHz and 300 GHz are called microwaves.

Advantages of Microwaves

1. Microwaves are unidirectional (sending and receiving antennas need to be aligned).
2. It propagation is line-of-sight ( the sending and receiving antennas need to be properly aligned with each other.)
3. Very high-frequency microwaves cannot penetrate walls.

Example of Microwaves

• Cellular phones
• Satellite networks
• Wireless LAN

Applications of Microwaves

• useful for unicast (one to one)

Infrared Definition

Infrared radiation (IR), is electromagnetic radiation (EMR) with longer wavelengths than those of visible light, and invisible to the human eye. Electromagnetic waves from frequencies between 300 GHz to 400 THz is called Infrared.

Advantages of Infrared

1. Infrared waves is used for short distance communication having high frequencies.
2. cannot penetrate walls.

Examples of Infrared Waves

• Burning charcoal
• Heat from an electric heater

Applications of Infrared

Infrared Data Association (IrDA) is used for communication between devices such as PCs, keyboards, mice, and printers. IrDA port allows wireless keyword to communicate with a computer.