EN 50173:2000 specifies cabling for use within commercial
premises which may comprise of single or multiple buildings
on a campus. It covers balanced copper cabling and optical
fiber cabling. The principles of this standard may be applied
to installations that do not fall within this range.
Cabling defined by this standard supports a wide range of
services including voice, data, text, image and video.
conformance requirements and verification procedures.
Cables and cords used to connect application specific equipment
to the generic cabling system are outside of the scope of
this standard. Since they have significant effect on transmission
characteristics of the channel, assumptions and guidance
are provided on their performance and length. Safety and
electromagnetic compatibility (EMC) requirements are outside
the scope of this standard and are covered by other standards
and regulations. However, information given in this standard
may be of assistance in meeting these standards and regulations.
Conformance
For a cabling installation to conform to this standard,
the configuration shall conform to the following;
Generic cabling schemes consist of three cabling sub systems:
Campus Backbone, building backbone and horizontal cabling.
This overview will deal with the horizontal element only,
although it will take into due consideration, the other
elements. The cabling subsystems are connected together
to create a generic cabling structure (as shown above).
The distributors provide the means to configure the cabling
to support different topologies like bus (ISDN), star (Ethernet)
and ring (Token Ring).
Campus Backbone Cabling Subsystem
The campus backbone cabling subsystem extends from the campus
distributor to the building distributor, usually located
in separate buildings. When present it includes the campus
backbone cables, the mechanical termination of the backbone
cables and the cross connections at the distributor. The
campus backbone may also interconnect building distributors.
Building Backbone Cabling Subsystem
A building backbone cabling subsystem extends from building
distributor(s) to floor distributor(s). The subsystem includes
the building backbone cables, the mechanical termination
of the backbone cables and the cross connections at the
building distributor. the building backbone cables shall
not contain transition points and copper cables should not
contain splices.
Horizontal Cabling Subsystem
The horizontal cabling subsystem extends from a floor distributor
to the telecommunications outlet(s) connected to it. The
subsystem includes the horizontal cables, the mechanical
termination of the horizontal cables and the floor distributor,
the cross-connections at the floor distributor and the telecommunications
outlets.
Horizontal cables should be continuous from the floor distributor
to the telecommunications outlets. If necessary, one transition
point is permitted between a floor distributor and any telecommunications
outlet. The transmission characteristics of the horizontal
cabling shall be maintained. The consolidation point shall
not be used as a point of administration (i.e. not used
as a cross-connect). and active equipment shall not be located
there.
Work Area Cabling
The work area cabling connects the telecommunications outlet
to the terminal equipment. It is non-permanent and application-specific
and therefore lies outside of the scope of EN 50173.
Telecommunications Outlet
Telecommunications outlets are normally located on the wall,
floor or elsewhere in the work area. Telecommunications
outlets may be presented singly, or in groups, but each
individual work area shall be served by a minimum of two.
Telecommunications outlets shall be marked with a permanent
label that is visible to the user. Pair re-assignment shall
be done by means of external adapters.
Telecommunications Closets and Equipment
Rooms
A telecommunications closet should provide all the faculties
(space, power, environmental control etc.) for passive components,
active devices, and public network interfaces housed within
it. Each telecommunications closet should have direct access
to the backbone.
Link Performance
Components and cables are defined as categories, however,
the link is defined a falling into one of four classes.
The standard divides installed copper links:
Class A -
|
Includes speech band and low frequency applications.
Copper cabling links supporting Class A applications
are specified up to 100KHz. |
Class B - |
Includes medium bit rate data applications. Copper
cabling links supporting Class B applications are specified
up to 1MHz. |
Class C - |
IIncludes high bit rate data applications. Copper
links supporting Class C applications are specified
up to 16MHz. |
Class D - |
Includes very high bit rate data applications. Copper
links supporting Class D applications are specified
up to 100MHz. |
Class E - |
Future applications. Copper links supporting Class
E applications are specified up to 250MHz.* |
Class F - |
Future applications. Copper links supporting Class
F applications are specified up to 600MHz.* |
For copper cabling links, link classes A to F are specified
such that they will provide the minimum transmission performance.