Network Media

Module 6.

Three Media Types

Modern networks use three types of media to interconnect devices:

• Metal Wires within Cables : data is encoded in electrical impulses

• Glass or Plastic Fibers within Cables : data is encoded into pulses of light

• Wireless Transmission : data encoded via modulation of frequencies of electromagnetic waves

The primary criteria for choosing a network media are:

• What is the max distance the media can successfully carry a signal?

• What is the environment the media will be installed in?

• What is the amount of data and what speed must it be transmitted?

• What is the cost of the media?

The three most common types of network cable are:

• Twisted Pair : wires are grouped in pairs and twisted to reduce interference, the pairs of wires are coloured so you can identify them at both ends. Typically one wire is solid colour and its partner is the same colour but with a white stripe.

• Coaxial Cable : copper cable used by cable TV companies, also used for connecting various components which make up satellite communication systems. This cable has a single rigid copper core which conducts the signal, the core is typically surrounded by insulation, metal shielding and a protective jacket.

• Fiber-Optic Cable : can be either glass or plastic, unaffected by electrical interference. Also used in medical imaging, medical treatment and mechanical engineering inspection.