Twisted Pair Cable

Twisted pair cable is the most common form of wiring in data communication application.

As a VGM (stands for voice grade medium), twisted pair cable is the basis for the most internal office telephone wiring.

Twisted pair cable consists of two identical wires that are wrapped together in a double helix.

Due to differences in the electrical characteristics, problems can occur between the pair, for example, length, resistance, capacitance. Therefore, for this reason, LAN applications will tend to use a cable of higher quality known as DGM (stands for data grade medium).

There are different types and categories of the twisted pair cable, but they all have the following two things in common:

  • the wires comes in pairs
  • the pairs of wires are twisted around each other

The twisting of wires reduces crosstalk. Here crosstalk means, the bleeding of a signal from one wire to another and which can corrupt the signal and cause network errors.

The twisting of wires not only protects the signal from internal crosstalk, but it also protects from other external forms of signal interference.

Types of Twisted Pair Cable

There are basically two types of the twisted pair cable, which are:

  • Shielded Twisted Pair (STP) Cable
  • Unshielded Twisted Pair (UTP) Cable

Unshielded Twisted Pair (UTP) Cable

The unshielded twisted pair (UTP) cabling is used for variety of electronic communications.

The unshielded twisted pair cables can have maximum segment length of 100 meters.

The unshielded twisted pair cable is available in five categories. All are described in the table given below:

UTP Type Description
CAT1 Voice-grade communications only. No data transmission
CAT2 Data-grade transmission upto 4Mbps
CAT3 Data-grade transmission upto 10Mbps
CAT4 Data-grade transmission upto 16Mbps
CAT5 Data-grade transmission upto 1000Mbps

Shielded Twisted Pair (STP) Cable

The shielded twisted pair (STP) cables comes with shielding of the individual pairs of wires, which further protects it from external interference.

Shielded twisted pair cables can have maximum segment length of 100 meters.

Advantage of STP over UTP Cable

The advantage of Shielded Twisted Pair (STP) over Unshielded Twisted Pair (UTP) is that it offers greater protection from interference and crosstalk due to shielding.

But shielded twisted pair cable is heavier and costlier than unshielded twisted pair cable and requires proper grounding at both the ends.

Advantages of Twisted Pair Cable

Here are the list of main advantages of twisted pair cable:

  • simple
  • easy to install and maintain
  • physically flexible
  • has a low weight
  • can be easily connected
  • very inexpensive

Disadvantages of Twisted Pair Cable

Here are the list of main disadvantages of twisted pair cable:

  • It is incapable carrying a signal over long distances without the use of repeaters only because of high attenuation
  • It is not suitable for broadband applications only because of its low bandwidth capabilities
  • It supports maximum data rates 1Mbps without conditioning and 10Mbps with conditioning

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