Transmission Medium
Transmission medium is the channel through which data is sent from one place to the other.
It is classified into the following types:
- Guided Media
In guided media, the signals being transmitted are directed and confined in a narrow pathway using physical links. It is also referred to as Wired or Bounded transmission media.
There are three major kinds of transmission media:
- Twisted Pair Cable
Several pairs of insulated conductor wires are wounded together in a protective sheath. It can be further divided into two types: Unshielded Twisted Pair and Shielded Twisted Pair.
- Coaxial Cable
Coaxial cable has an outer plastic covering containing 2 parallel conductors and each of them has a separate insulated protection cover. It transmits information in 2 modes: Baseband mode and Broadband mode.
- Optical Fibre Cable
In an optical fibre cable, the core is surrounded by a less dense glass or plastic covering called cladding. It is generally used for the transmission of huge data. The Wavelength Division Multiplexer or WDM supports unidirectional and bidirectional modes.
- Stripline
Stripline uses a conducting material to transmit high-frequency waves called waveguide. The conducting material is between the two layers of the ground plane which are shorted to give EMI immunity.
- Microstrip line
It is similar to a stripline, but the ground plane is separated by a layer of dielectric.
- Unguided Media
In unguided media, no physical medium is required for the transmission of electromagnetic signals.
These are the following types of signals transmitted through unguided media:
- Radio Waves
- Microwaves
- Infrared.