Twisted Pair Cables
Twisted pair cables, as their name suggests, consist of one or more pairs of twisted wires that form the data transmission circuit. The conductor of these wires is generally made of copper and each pair is twisted together. One of the conductors is used to carry the signal and the other is only used as a ground reference.
Twisted pair cable is used to connect computers, switches, routers, printers and CCTV cameras. These cables are used in telephone lines to provide data and voice channels, in DSL lines, and also for analog and dialog transmission.
Why are they intertwined?
Two parallel conductors have a high degree of interference or noise. Twisted paired wires significantly reduce interference in adjacent cable pairs. In this way, when an electric current passes through a wire, a magnetic field is created around the wire, and when two similar wires are placed in an electric circuit, they create equal and opposite magnetic fields. Two magnetic fields or any external magnetic field cancel each other out. Therefore, when the two wires are twisted, they eliminate or reduce this interference and noise.
Types of Twisted Paired Cables
The main classification of paired cables is based on whether their wires are shielded or not. A shield or shield in the form of foil or copper that protects the cable conductors by covering them.
1- Unshielded Twisted Pair Cable (UTP)
In these cables, one of the conductors is used for transportation and the other is only used as a legacy wire. The receiver uses the signal difference between these two conductors. There is a lot of noise in two parallel conductors, but in paired cables, due to the twisting feature, this amount is greatly reduced; In this way, in the first turn, one conductor is close to the source of noise and the other one is far from the source, but in the next turn, the opposite happens and the resulting noise is much less, and as a result, the balance in the quality of the signal is maintained. The quality of the signal in the twisted-pair cables largely depends on the number of turns per unit length of the cable. UTP cables are mostly used in short distance transmission for telephone wires, Ethernet cables and LANs.
Advantages
– Cost-effectiveness
– Easy installation
– Optimum transmission of voice and data in short distances
Disadvantages
– Low connection safety established
– The functional length of these cables is usually up to 100 meters and they are less efficient for longer distances
– Limited bandwidth
2- Shielded Twisted Pair Cable (STP)
These types of cables have additional insulation or protective coating on the conductors in the form of copper braided coating. This coating provides the strength of the overall structure of the cable. It also reduces noise and signal interference in the cable. This shield ensures that the induced signal can be returned to the source through ground. STP cables are color-coded like UTP cables because different color pairs are needed for analog and digital transmission. These cables are expensive and more difficult to install. STP twisted pair network cable is often used in development applications that require high bandwidth and outdoor environments.
Advantages
– Suitable for long distance communication and transmission
– The protective cover prevents the penetration of external electromagnetic noise into the cable.
– Higher bandwidth than UTP
Disadvantages
– Very high cost
– High cost of maintenance
– Installation only underground
What is the difference between UTP and STP?
UTP cables have wires twisted together to reduce noise created by an external source by the cancellation effect. STP cables also have four pairs of twisted pair cables but are enclosed in an additional shield. The shield protects the conductors from electromagnetic interference and eliminates the interference. UTP cables are cheaper and lighter than STP cables, but they have slower speeds.
Classification of paired cables
Paired cables are classified with the Cat (Category) abbreviation prefix and with single-digit numbers based on bandwidth and data transfer volume, which is presented in the table below.
What is a UTP LAN?
LAN UTP is an unshielded twisted pair cable that is often used in local area network configurations. Two unshielded wires wrapped around each other. UTP cabling is inexpensive and widely used for LANs or home or local area networks. Compared to coaxial or fiber optic cables, UTP cable has lower bandwidth and lower immunity to interference. However, it is easy to install and costs less.
What is the difference between a pair cable and a coaxial cable?
While a twisted-pair cable consists of a pair of twisted copper wires, a coaxial cable has two conductors. The inner conductor is inside the insulation and is surrounded by another conductor that acts as a shield. The outer conductor is covered by a shield or an insulating cover.
A twisted-pair cable transmits signals through copper wires. Coaxial cables transmit signals through the inner conductor of the cable. Compared to twisted pair cables, coaxial cables are noise shielded and support relatively higher bandwidth.
Why is a pair cable better than a coaxial cable?
Because of less shielding, twisted-pair cables are thinner, less expensive, and easier to install. Therefore, they are suitable for providing high transfer rates over computer LANs and Ethernet. Coaxial cables, on the other hand, are better shielded and therefore better immune to interference, but are more expensive than single-pair cables.
Conclusion
Despite problems such as limited bandwidth or distance limitations, paired cables are among the most widely used wires and cables in the field of networks due to their cost-effectiveness and easy installation. These cables are an ideal choice for use in short distances by reducing interference.
Zerkabel Kerman Company, a specialized producer of all kinds of low voltage wires and cables, offers products in the field of telecommunication and network cables, including paired cables. To see the products of Zerkabel company in the field of paired cables, you can refer to the products page.
