Cables for Installations and Industry - Draka

DATA CA BLES
64
GEN ERAL
GE NE RIC CAB LING SYS TEMS
Generic cabling is applied to telecommunication cabling
as a permanent part of the office to meet the expanding
needs of the user’s. It meets also the future data
transmission requirements including new computers and
relocation of the workstations on the premises
- minimizing the need for new cabling.
The physical structure of a generic cabling system is
star-shaped. This makes the network control easier which
is important especially now when the telecommunication
and data networks in buildings are the property of
the owner. A star-shape cable system allows to change
the network topology from the cross-connection to a bus
or a ring. In a star-shape system all the active components
can be placed together in one space which is easy to
control and can be locked and which improves data
security. Also measurements and maintenance are easier
to carry out in the cross-connection area. lf one branch of
the star network falls off the whole system is not paralyzed
because the faulty branch can be disconnected from the
network.
The generic cabling system is not really open until its
components are vendorindependent. They just have to
conform to the standards. When planning a cable system
it is important to consider what the openness really means
and how open the non-compatible and vendor-dependent
cable systems are.
STAN DARDS
The European standard for the generic cabling systems
is EN 50173 which was set up on the basis of the
international ISO/IEC 11801. The corresponding standard
in the U.S. is ANSI/TIA/EIA 568-A supported by TIA and
EIA. The EN 50173 applicable in Europe defines the
different transmission line applications and classes as well
as the categories 3 and 5 for the line components.
For example, a data network that fulfills the requirements
of class D can be set up from components of category 5.
EN 50173 recommends the use of 100 Ω twisted-pair
cables in horizontal cabling.
Cat. 6 standard will be ready in 2001.
SCREENING
The abbreviations UTP, FTP and STP-screening
construction are used to refer to the cable. UTP is a cable
where symmetrical twisted pairs are used for screening.
A FTP cable has an overall metal shield, and in a STP
cable all the pairs are screened separately. The cable type
is chosen to suit the environment where it’s used.
In Finland most of the installations are made with FTP and
UTP cables. Optical fibre cables are recommended for
local and rising cabling.
The STP may also be marked ScTP and S/STP, meaning
a construction with a pair and an overall shield.
AP PLI CA TION AND TRANS MIS SION
CLASSES
Transmission
classes
A
B
C
D
Application Maximum
frequency
Voice band and
low-frequency
applications
100 kHz
Medium-speed
data applications 1 MHz
Fast data
applications 16 MHz
Very fast data
applications 100 MHz
E Very fast data
applications 200 MHz
OPTICAL
Very fast data
applications
A ge neric ca bling sys tem con structed for a cer tain
ap pli ca tion con sists of one or sev eral trans mis sion lines.
REC OM MEN DA TIONS
— It is important to examine the building needs very
carefully, including e.g. the existing network and
the desires for more extended data transmission
in the future.
— The maximum length of horizontal cabling is 90 m.
The maximum length of cross-connection and
equipment cabling is 10 m.
— An optical fibre cable is recommended for local and
rising cabling.
— Two double cables should be installed for each work
area, in order to meet the increasing need of
telecommunication.
DATA TRANSMISSION CABLES
Our complete range of UC cables fulfills tomorrow’s
needs. Our new product family UC 400 is designed for
applications beyond CAT 5 with good properties.
Our new development for the high-end field is UC 1000.
A cable class that not only fulfills the above mentioned
standards, but also offers reserves, allowing base band
transmission of Gigabit-Ethernet.
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