February 29, 2012

Significance of the twisting in twisted-pair cable

Twisted pair cables are of two types

1-         UTP (Unshielded Twisted Pair)

2-         STP (Shielded Twisted Pair)


It is cost effective; the cost is the main advantage which it provides.


There are 5 categories of UTP

Category 1: Low speed data, fine for voice

Category 2: Works for data transmission but up to 4mbps only, suitable for voice

Category 3: Data transfer rate Up to 10mbps, it gives 3 twists per ft.

Category 4: Data transfer rate Up to 16MB, it gives 3 twists per ft.

Category 5: Data transfer rate Up to 100MB

Role in Noise Control:

It helps us to reduce noise, because there can be from 2 to 12 twists in one feet area. Twisted pair cable divide the effect of the noise between two wires twists. When noise will interfere data transmitting process, twist will have half of the time noise and then half of the time noise free. By this way at the end if noise is not completely eliminated but it will be reduced.


In shielded twisted pair cable we can have many pairs of unshielded twisted pair cable in it covered with a plastic cover. Inside the plastic cover we have a metal shield to prevent the electromagnetic interference, and cross talk. It is costly than UTP but on other hand it provides the noise free data transmission activity.

Last updated: March 19, 2014