Category 3 cable
Encyclopedia
Category 3 cable, commonly known as Cat 3 or station wire, is an unshielded twisted pair (UTP)
cable
designed to reliably carry data up to 10 Mbit/s, with a possible bandwidth of 16 MHz. It is part of a family of copper cabling standards defined jointly by the Electronic Industries Alliance
and the Telecommunications Industry Association
.
Category 3 was a popular cabling format among computer network
administrators in the early 1990s, but fell out of popularity in favor of the very similar, but higher performing, Category 5 cable
standard. Since the early 2000s most new structured cable installations are built with Cat 5e or Cat 6
cable.
Cat 3 is currently still in use in two-line telephone systems. It may be used for 10BASE-T
Ethernet, token ring, or ATM25
networks. The seldom used 100BASE-T4 standard, which achieves speeds of 100 Mbit/s by using all 4 pairs of wires, allowed older Cat 3 based infrastructures to achieve a much higher bandwidth.
Cat 3 is compatible with the original Power over Ethernet
specification though it does not support the new 802.1at Type 2 high-power variation.
Note that unlike Cat 1
, 2
, 4
, and 5
cables, Cat 3 is still recognized by TIA/EIA-568-B, its defining standard.
Twisted pair
Twisted pair cabling is a type of wiring in which two conductors are twisted together for the purposes of canceling out electromagnetic interference from external sources; for instance, electromagnetic radiation from unshielded twisted pair cables, and crosstalk between neighboring pairs...
cable
Cable
A cable is two or more wires running side by side and bonded, twisted or braided together to form a single assembly. In mechanics cables, otherwise known as wire ropes, are used for lifting, hauling and towing or conveying force through tension. In electrical engineering cables are used to carry...
designed to reliably carry data up to 10 Mbit/s, with a possible bandwidth of 16 MHz. It is part of a family of copper cabling standards defined jointly by the Electronic Industries Alliance
Electronic Industries Alliance
The Electronic Industries Alliance was a standards and trade organization composed as an alliance of trade associations for electronics manufacturers in the United States. They developed standards to ensure the equipment of different manufacturers was compatible and interchangeable...
and the Telecommunications Industry Association
Telecommunications Industry Association
The Telecommunications Industry Association is accredited by the American National Standards Institute to develop voluntary, consensus-based industry standards for a wide variety of ICT products, and currently represents nearly 400 companies...
.
Category 3 was a popular cabling format among computer network
Computer network
A computer network, often simply referred to as a network, is a collection of hardware components and computers interconnected by communication channels that allow sharing of resources and information....
administrators in the early 1990s, but fell out of popularity in favor of the very similar, but higher performing, Category 5 cable
Category 5 cable
Category 5 cable is a twisted pair cable for carrying signals. This type of cable is used in structured cabling for computer networks such as Ethernet. It is also used to carry other signals such as telephony and video. The cable is commonly connected using punch down blocks and modular connectors...
standard. Since the early 2000s most new structured cable installations are built with Cat 5e or Cat 6
Category 6 cable
Category 6 cable, commonly referred to as Cat 6, is a cable standard for Gigabit Ethernet and other network physical layers that is backward compatible with the Category 5/5e and Category 3 cable standards. Compared with Cat 5 and Cat 5e, Cat 6 features more stringent specifications for crosstalk...
cable.
Cat 3 is currently still in use in two-line telephone systems. It may be used for 10BASE-T
10BASE-T
Ethernet over twisted pair technologies use twisted-pair cables for the physical layer of an Ethernet computer network. Other Ethernet cable standards employ coaxial cable or optical fiber. Early versions developed in the 1980s included StarLAN followed by 10BASE-T. By the 1990s, fast, inexpensive...
Ethernet, token ring, or ATM25
ATM25
ATM25 is an ATM version wherein data is transferred at 25.6 Mbit/s over Category 3 cable. ATM25 has no particular distinctions from other ATM versions. However, ATM25 chipsets are inexpensive in comparison to faster ATM chipsets, having the result of making ATM technology available for small...
networks. The seldom used 100BASE-T4 standard, which achieves speeds of 100 Mbit/s by using all 4 pairs of wires, allowed older Cat 3 based infrastructures to achieve a much higher bandwidth.
Cat 3 is compatible with the original Power over Ethernet
Power over Ethernet
Power over Ethernet or PoE technology describes a system to pass electrical power safely, along with data, on Ethernet cabling. The IEEE standard for PoE requires category 5 cable or higher for high power levels, but can operate with category 3 cable for low power levels...
specification though it does not support the new 802.1at Type 2 high-power variation.
Note that unlike Cat 1
Category 1 cable
Category 1 cable a.k.a. voice-grade copper is a misnomer, probably adopted by those who assumed that TIA set up "Categories" for all types of cables originally defined by Anixter International, the distributor, under the grades called "Levels." Cat 1 cable is used in earlier times...
, 2
Category 2 cable
Category 2 cable, or simply Cat 2, is a misnomer, probably adopted by those who assumed that the Telecommunications Industry Association set up "Categories" for all types of cables originally defined by Anixter, the distributor, under the grades called Levels. TIA-568 only recognized cables of...
, 4
Category 4 cable
Category 4 is a description of a cable that consists of four unshielded twisted-pair wires with a data rate of 16 Mbit/s and performance of up to 20 MHz. It was used in token ring networks, 10BASE-T, 100BASE-T4, and is no longer common or used in new installations. It is used in telephone...
, and 5
Category 5 cable
Category 5 cable is a twisted pair cable for carrying signals. This type of cable is used in structured cabling for computer networks such as Ethernet. It is also used to carry other signals such as telephony and video. The cable is commonly connected using punch down blocks and modular connectors...
cables, Cat 3 is still recognized by TIA/EIA-568-B, its defining standard.