Frequently Used Unshielded Twisted Pair Cable Types

As the demand for faster data transmission greatly increases, fiber optic cables have been more preferable than copper cables. However, copper cables, with low cost, easy operation and great flexibility, are still found in many electrical and electronic related devices. As an indispensable part in copper cabling, unshielded twisted pair cable has great potential in the field of short distance transmission. Today, I would like to introduce several frequently used types of unshielded twisted pair cable.

Unshielded twisted pair cable (UTP) (shown in the following picture) is a famous category of the copper cables that is utilized in copper network. It consists of color-coded copper wires, which are twisted around each other, to reduce the interference and crosstalk. With compact size, UTP cables can be installed easily, particularly in bulk or in narrow spaces. Though UTP cable does not provide bandwidth as high as coaxial cables or fiber optic cables (like LC fiber cable), it has low cost and does not require as much maintenance without the outer shield, making them extensively used. However, UTP cables are more prone to cause electrical noise and interference than other types of networking media. Thus, UTP cables are preferred for domestic and office Ethernet connections, and in any area where there is not a high degree of electromagnetic interference.

UTP cable has become the commonly used twisted pair wiring in Ethernet 10Base-T and 100Base-T networks. The following part introduces several UTP standards that are frequently used nowadays.

Around the year of 2000, Cat5 UTP cable was introduced to replacecat3 as the Ethernet cable for LAN networking. Cat5 UTP cable has four pairs of twisted copper wires as same as cat3 UTP cable, but cat5 has more twists per inch than cat3, therefore, it can run at a higher speed, up to 100Mbps and greater lengths, as long as 100 meters. Cat5 UTP cable was the first Ethernet-capable cable. However, it has been replaced for the most part by cat5e.

Cat5e unshielded twisted pair cable is the improved form of cat5 UTP cable, which is able to transmit data at a speed of around 1Gbps. While similar to cat5 in appearance, cat5e introduces some new links in the equation. For one thing, cat5e uses four pairs of copper wire rather than the two that cat5 relies on. In addition, the wire pairs are twisted more tightly to eliminate crosstalk. Due to its internal upgrades, including faster transmission rate and higher bandwidth, cat5e UTP cable has become the most common type of cabling found in modern homes and offices for Ethernet purposes.

Cat6 UTP cable is a standardized twisted cable, which can support 1G Ethernet for the length up to 100 m, and 10G Ethernet for the length up to 55 m. It is similar to cat5e, but contains a physical separator between the four pairs to further reduce electromagnetic interference. And compared with cat5/cat5e UTP cable, cat6 UTP cable features more stringent specifications for crosstalk and system noise. It is normally applied for the Ethernet computer’s network, telephone services. But its installation is more difficult than the other categories of cat5 and cat5e. Here is an image showing the differences among cat5, cat5e and cat6 UTP cables.

In 2009, cat6a was introduced as a higher specification cable, offering better immunization to crosstalk and electromagnetic interference. The “a” stands for “augmented” and is a nod to cat6a’s improved specification compared with cat6. The cat6a doubles data transmission bandwidth, from 250 MHz to 500MHz, decreases the chance of crosstalk interference, and provides superior reliability and transmission speeds through greater lengths of cable. The easiest way to tell cat6a from cat6 is that cat6a UTP cable is much thicker and bulkier than cat6 UTP cable. Appearance of cat6a (black) vs cat6 (blue) shown in the picture below.

As a standard copper cable, unshielded twisted pair cable is widely used to join different home or business computers along with a telephone company for the communication and information exchange purposes. Cat5, cat5e, cat6 and cat6a are commonly used types of UTP cable. Cat5 and cat5e UTP cables are much more cheaper and can be installed easily, while cat6 and cat6a cables have better performance and can operate at higher speed for longer length. Hope you can choose the appropriate UTP cable after reading this passage.