Introduction to Networking and Data Communication

Data Communication Media Lesson I

By the end of this lesson you should be able to: To define data communication media Describe different types of bounded communication media

Data communication media refers to the pathway through which data signals are transferred from on place to another. Data Communication media are classified as:

• Bounded communication media(use of cables/wired)
• Unbounded communication media(wireless )

Bounded Communication Media

In this type, data signals are relayed through cables. These media are again divided into :

• Two open cables
• Twisted pair cables
• Coaxial Cables
• Fibre optic Cables

Two wire open line cables

These are made up of two parallel copper wires separated by a plastic insulator. They are used to transmit voice signals over telecommunication networks. This type of bounded media suffer from EMI as the lines are parallel to each other.

Twisted Pair Cables

These are copper wires wound on each other. The winding/twisting reduces electromagnetic interference and crosstalk. They are divided into:

• Unshielded twisted pair (UTP)
• Shielded Twisted Pair (STP)

 

Unshielded Twisted Pair (UTP)

They are not shielded using braids of copper wire or aluminium foil. They suffer from electromagnetic interference. These interferences may come from lightning sparks, radio signals etc.

Advantages of TP cables

• It is cheap due mass production of for telephone use
• Installation of equipment is cheap and readily available
• It is easier to set up network  omedia because connection is readily available

Disadvantages of TP cables

• it suffers from loss of strength of data signals
• It is prone to electromagnetic interference and eavesdropping
• It has low transmission rates as compared to other cables

Shielded Twisted Pair (STP)

Here, shielding  is done by use braided copper wires and aluminium foil to prevent electromagnetic interference

By Hurzelchen, CC BY-SA 3.0,

Twisted pair Cable