• In a network, a communication channel is a physical path the transmission signals travel.
    • It is the path information travels from computer to computer.
    • How do the computers in a network “connect” to each other.

The 5 communication channels

  • twisted-pair cables
  • coaxial cables
  • fiber optic cables
  • terrestrial stations
  • communication satellites

Twisted pair cables

  • Signals are transmitted using pairs of independently insulated wires that have been physically twisted together
  • Used by older telephone networks
  • Network cables use an RJ-45 jack for four pairs of twisted-pair cables.

Coaxial cables

  • Core of the wire is copper
  • High frequency signals can be carried on a single cable – used for video transmission
  • Used when twisted pair cabling is not adequate to carry the required amount of data.

Fibre Optic Cables

  • Digital signals are sent as light pulses which are translated back into electrical signals
  • Composed of fine glass strands
  • The Centre core is composed of: Fine glass strand surrounded by glass cladding and protective layer
    • Glass cladding reflects light back into the core, guiding the light along the wire
  • Thousands of transmissions can be carried on a single strand
  • Can transmit signals faster than twisted pair and coaxial cables

Terrestrial Stations

  • Information is sent via microwaves from ground based transmitting and receiving stations
    • Text, sound, and graphics are converted into microwave pulses and transmitted
  • Microwave stations (a.k.a. repeater stations)  must be placed every 50 kilometres to receive, amplify, and then pass the signal along
  • Transfer information at much higher speeds than cabling

Communication Satellites

  • Orbiting around earth
  • Avoids cost of cabling and repeater stations
  • Minimum of three satellites are needed to provide world-wide communication
  • Transfer information at much higher speeds than cabling
author avatar
William Anderson (Schoolworkhelper Editorial Team)
William completed his Bachelor of Science and Master of Arts in 2013. He current serves as a lecturer, tutor and freelance writer. In his spare time, he enjoys reading, walking his dog and parasailing. Article last reviewed: 2022 | St. Rosemary Institution © 2010-2024 | Creative Commons 4.0

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