|  | | | Since the early 1980's, generic structured cabling networks have surpassed proprietory cabling networks as the most popular solution for the transmission of voice, data and multimedia.
Copper cabling will remain the chosen media for the foreseeable future due to its low cost and ease of installation.By defining a set of uniform standards for signal transmission, system construction and performance testing, manufacturers and system integrators have a set of guidelines to work to and purchasers have a means of comparing one structured cabling system's performance with another.
This technical update provides an overview of current cabling standards for end users and specifiers, and introduces the latest proposed performance standards to which the major system manufacturers are already working to achieve.
Current Standards
International structured cabling standards are ratified by the International
Standards Organisation (ISO), part of the United Nations and therefore
recognised by national governments.
There are other national (US) bodies whose status is such that they have
international acceptance. These include the Electronic Industries Alliance
(EIA) and the Telecommunications Industry Association (TIA).
Within the field of structured cabling, three standards are broadly comparable:
ANSI/TIA/EIA 568-B (US), CENELEC EN50173 (Europe) and ISO/IEC 11801
(International). The equivalent British Standard is BS EN 50173. ISO/IEC 11801,
Generic Cabling Standard sets out five performance classes of copper cabling
installation to suit different applications:
Class A - is for voice telephony up to 100 KHz.
Class B - covers frequencies to 1 MHz for voice and slow speed links to IBM
3270 terminals and similar.
Class C - (Category 3) - represents frequencies to 16 MHz and is suitable for
most of the data applications in place prior to 1990.
Class D - (Category 5) - was drafted in 1992, and finally ratified in 1995.
Since its ratification several updates have been issued to bring the standard
up-to-date. The latest version is known as Category 5 Enhanced (Cat 5e).
Structured cabling systems conforming to Class 1, 2 and 3 still exist, however,
Class D (Category 5) is the recognised standard for modern network
applications. Class D (Category 5) installations are well established around the
world, with approximately 99% of new and refurbishment structured cabling
installations specified to Class D or above.
Class E - (Category 6) - is the latest cabling standard to emerge from ISO/TIA
and is designed to support the high speed data protocols of tomorrow.
Class F - (Category 7) - is the proposed 600 MHz standard for shielded
structured cabling solutions. (This is not part of the TIA standard)
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