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 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.
There are basically two types of the twisted pair cable, which are:
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:
|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|
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.
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.
Here are the list of main advantages of twisted pair cable:
Here are the list of main disadvantages of twisted pair cable: