Tuesday, July 19, 2011

ISO/IEC 11801

ISO/IEC 11801

The International Organization for Standardization (ISO) and the International Electrotechnical Commission (IEC) publish the ISO/IEC 11801 standard predominantly used in Europe. This standard was released in 1995 and is similar in many ways to the ANSI/TIA-568-C standard upon which it is based. The second edition was released in 2002 and is largely in harmony with ANSI/TIA-568-C. However, the ISO/IEC 11801 standard has a number of differences in terminology. Table 1 shows the common codes and elements of an ISO/IEC 11801 structured cabling system.

Differences between ANSI/TIA-568-C and ISO/IEC 11801

Differences between ANSI/TIA-568-C and ISO/IEC 11801 Ed. 2 include the following:
  • ISO/IEC 11801 allows for an additional media type for use with backbone and horizontal cabling and 120 ohm UTP.
  • The term consolidation point is much broader in ISO/IEC 11801; it includes not only transition points for under-carpet cable to round cable (as defined by ANSI/TIA-568-C), but also consolidation point connections.
Table 1: Common Codes and Elements Defined by ISO/IEC 11801 
Element
Code
Description
Building distributor
BD
A distributor in which building-to-building backbone cabling terminates and where connections to interbuilding or campus backbone cables are made.
Building entrance facilities
BEF
Location provided for the electrical and mechanical services necessary to support telecommunications cabling entering a building.
Campus distributor
CD
Distributor location from which campus backbone cabling emanates.
Equipment room
ER
Location within a building dedicated to housing distributors and application-specific equipment.
Floor distributor
FD
A distributor used to connect horizontal cable to other cabling subsystems or equipment.
Horizontal cable
HC
Cable from the floor distributor to the telecommunications outlet.
Telecommunications room
TC
Cross-connection point between backbone cabling and horizontal cabling. May house telecommunications equipment, cable terminations, cross-connect cabling, and data networking equipment.
Telecommunications outlet
TO
The point where the horizontal cabling terminates on a wall plate or other permanent fixture. The point is an interface to the work area cabling.
Consolidation point
CP
The location in horizontal cabling where a cable may end, which is not subject to moves and changes, and another cable starts leading to a telecommunications outlet, which easily adapts to changes.
Work-area cable
None
Connects equipment in the work area (phones, computers, etc.) to the telecommunications outlet.
ISO/IEC 11801 Ed. 2 specifies a maximum permanent link length of 90 meters and a maximum channel link of 100 meters. Patch and equipment cord maximum lengths may be adjusted by formulas depending on the actual link lengths. Terminology differences between ANSI/TIA-568-C and ISO/IEC 11801 Ed. 2 include the following:
  • The ISO/IEC 11801 Ed. 2 definition of the campus distributor (CD) is similar to the ANSI/TIA-568-C definition of a main cross-connect (MC).
  • The ISO/IEC 11801 Ed. 2 definition of a building distributor (BD) is equal to the ANSI/TIA-568-C definition of an intermediate cross-connect (IC).
  • The ISO/IEC 11801 Ed. 2 definition of a floor distributor (FD) is defined by ANSI/TIA-568-C as the horizontal cross-connect (HC).

Classification of Applications and Links

ISO/IEC 11801 Ed. 2 defines classes of applications and links based on the type of media used and the frequency requirements. ISO/IEC 11801 Ed. 2 specifies the following classes or channels of applications and links:
Class A For voice and low-frequency applications up to 100kHz.
Class B For low-speed data applications operating at frequencies up to 1MHz.
Class C For medium-speed data applications operating at frequencies up to 16MHz.
Class D Concerns high-speed applications operating at frequencies up to 100MHz.
Class E Concerns high-speed applications operating at frequencies up to 250MHz.
Class EA Concerns high-speed applications operating at frequencies up to 500MHz.
Class F Concerns high-speed applications operating at frequencies up to 600MHz.
Class FA Concerns high-speed applications operating at frequencies up to 1000MHz.
Optical Class An optional class for applications where bandwidth is not a limiting factor.

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