Network Cables Introduction

Cable in Network is like vein in human body because it is the medium through which all information transmits. There are various types of cable. Selection of cable needs some consideration such as cost, protocol, network topology etc. Some of them are as follow:

Twisted Pair Cable

As the name suggested in twisted pair cable, a pair of cable twisted with each other. In this formation they cancel the internal magnetic field created by them for carrying signal and external magnetic field when they pass beside electrical circuit or devices. It gives better protection from internal and external noises. Most telephone communication and Ethernet media use twisted pair cable as transmission medium. Two types of twisted pair cable exist.

1) Unshielded Twisted Pair Cable (UTP)

2) Shielded Twisted Pair Cable (STP)

Unshielded Twisted Pair Cable

It is most common and popular cable used for general purpose by the general people. Because it is cost effective and satisfy the demand and can be used anywhere except environment with lots of interference and where 100% accuracy is needed. In unshielded twisted pair cable there are no shield provided. The interference from noise is avoided only using twisting technique. Some variety of UTP exists according to type and speed of the network. They are as follow:

Category 1—1 Mbps — used for voice communication (Telephone wire)

Category 2—4 Mbps—can be used for Local talk but it is rarely used.

Category 3—16 Mbps—used in 10BASE-T Ethernet.

Category 4—20 Mbps—Used in Token Ring.

Category 5—100 Mbps (2 pair)/1000 Mbps (4 pair)—Can be used in 100BaseT Ethernet Gigabit Ethernet

Category 5e —1000 Mbps—Gigabit Ethernet

Category 6—10,000 Mbps—cable consists of four pairs of 24 American Wire Gauge (AWG) copper wires.

The standard connector for UTP is RJ45 and its range is 100m.

Shielded Twisted Pair Cable 

Shielded Twisted pair cable reduces the limitation of unshielded twisted pair cable. It can be used in almost any area which has highly potential interference as it combines the shielding technique with twisting technique.  In STP each four pairs of cable are wrapped with metallic foil then all four pairs again wrapped with metallic foil making it more interference resistance. STP shielding must be grounded on both ends. STP data connector usually used for STP cable but RJ45 also can be used as connector.  Its range is also 100 meter. STP is less used than UTP due to its difficult termination and cost.

Coaxial Cables

Here “Coaxial” stands for the common axis of the two conductors. The two conductors are the central solid conductor and the outer metal shield. In a coaxial cable a solid conductor in center is surrounded by a non-conducting /insulating material. Which is by then surrounded by metal foil or bread and finally a plastic cover is surrounded all over them.

Coaxial cable is most popular for transmitting the video signal like cable TV etc. It is also used as Ethernet transmission medium. Two types of coaxial cable used as Ethernet transmission medium.

1)                  Thin coaxial cable

2)                  Thick coaxial cable

There are also other classifications. Coaxial cable that satisfy the United States Government specification are designated as RG such as RG59/U, RG6/U and RG11/U. Here R stands for Radio Frequency, G stands for Government, the third digit specifies government approval number and /U stands for universal specification.

The most common connector used for coaxial cable is BNC connector. BNC stands for Bayone-Neill-Concelman. There are several types of BNC connector.

Its range is better than the Twisted pair cable.

Fiber Optic Cable

Another revolutionary communication media of the modern world is Fiber Optic cable. The details of fiber optic are found in Wikipedia. It has greater range and speed. Used in super fast communication.