Unguided media, also known as wireless media, refers to the transmission medium that transports data without the use of physical medium.
• It utilizes electromagnetic waves to transmit data over the air. This type of communication is essential for mobile, satellite, and other wireless communications.
• Unlike guided media, unguided media does not rely on a physical path for signal transmission.
1.) Radiowaves
Radiowaves are a type of electromagnetic wave with wavelengths longer than infrared light. They are used for transmitting data wirelessly over long and short distances.
Characteristics:
- Frequency Range: Typically ranges from 3 kHz to 300 GHz.
- Propagation: Can travel long distances and penetrate through buildings and other obstacles.
- Uses: Broadly used in broadcasting (radio, TV), communication systems (Wi-Fi, mobile networks), and other wireless applications.
2.) Microwaves
Microwaves are a type of electromagnetic wave with wavelengths ranging from one meter to one millimeter, or equivalently, frequencies between 300 MHz (0.3 GHz) and 300 GHz.
Characteristics:
- Frequency Range: 1 GHz to 300 GHz.
- Propagation: Line-of-sight communication; typically requires direct paths without obstructions.
- Uses: Widely used in satellite communication, radar systems, and point-to-point communication links.
Types of Microwaves:
1.) Terrestrial Microwave:
- Used for point-to-point communication on the Earth’s surface.
- Applications: Long-distance telephone transmission, TV signals, and data communication.
- Equipment: Requires microwave antennas (dishes) positioned for line-of-sight transmission.
2.) Satellite Microwave:
- Uses satellites to relay signals from one point on Earth to another.
- Applications: International telecommunication, TV broadcasting, internet services.
- Equipment: Ground stations with satellite dishes to send and receive signals to and from satellites in orbit.
