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To date, Ethernet is the most commonly used technology for 2. The building backbone cabling connects the build-
local area networks. The name “Ether” refers to the first radio ing distributors to the floor distributors. Also in this case,
networks. Introduced in the 1980s, the 10 MBit Ethernet used 50 µm optical fibre cables and balanced 100 ohm cables
coaxial cables. Later Fast Ethernet with 100 MBit/s and Giga- with a length of 500 m are mainly used.
bit Ethernet with 1000 MBit/s and 10 GBit/s were introduced. 3. The horizontal cabling (floor distributor) includes all ca-
All Ethernet versions are based on the same principles. From bles of the work stations of a floor and should not exceed
the 1990s on, Ethernet became the most widely used LAN 90 m. Copper cables or in some cases 62.5 µm optical fi-
(Local Area Network) technology and replaced other LAN bre cables are typically used to connect the floor distribu-
standards such as Token Ring and ARCNET. Ethernet consists tor to the telecommunication outlet.
of different types of 50 Ω coaxial cables or twisted pair ca-
bles, glass fibre cables or other media. At present, Ethernet The interfaces between these areas form passive distribu-
typically has a data rate of 100 MBit/s, however, data rates tion panels. Such distribution panels link the campus back-
of 1000 MBit/s are on the rise. bone, building backbone and horizontal cabling of universal
Surges cause malfunction and destruction and thus failure cabling systems. They allow to easily start communication
of computer systems. This can significantly affect operations, services on a work station by simply patching patch cables.
resulting in long standstill of the installations and systems. Distribution panels for optical fibre cables (campus backbone
Therefore, surge protection concepts are required in addition and building backbone) and twisted pair cables (horizontal
to the protection of the power supply system and regular cabling) differ according to the number of ports. For example,
data backups to ensure reliable operation of computer sys- 24 ports are commonly used for structured cabling systems
tems. and 25 ports for telecommunication installations. Cables are
typically installed in 19 ” data cabinets or racks.
Causes of damage Star topologies are used for generic cabling systems. All cur-
Failure of computer systems is typically caused by: rently available protocols can be operated by means of star
¨ Remote lightning strikes causing conduced transients in topologies irrespective of whether they form a logical ring
power supply, data or telecommunication lines, or bus system.
¨ Nearby lightning strikes causing electromagnetic fields Structured cabling systems connect all terminal devices. They
that inject transients into power supply, data or telecom- allow communication between telephones, networks, safety
munication lines, systems, building automation systems, LAN and WLAN inter-
¨ Direct lightning strikes causing impermissibly high poten- connection as well as access to the intranet and internet.
Generic cabling systems ensure flexible use of terminal de-
tial differences and partial lightning currents in the build- vices. It is assumed that all information such as data, voice,
ing installations. television, automation and control of machines and installa-
tions will be transmitted via Ethernet over the next years and
Structured cabling as uniform connection medium Ethernet will thus become a universal transmission concept.
Structured cabling is a uniform connection medium for differ- Therefore, electromagnetic compatibility (EMC) must be en-
ent services such as analogue telephones, ISDN or different sured.
network technologies. Consequently, existing installations
can be easily adapted to new tasks without exchanging the EMC concept
cables or connection parts. A structured cabling system pro- Electromagnetic compatibility is defined as the capability
vides application-independent and universal cables which of a device – especially of an installation or a system – to
are not tailored to a specific network topology, manufacturer properly operate in its electromagnetic environment without
or product. The type of cables and the topology ensure that causing electromagnetic interference itself which would be
all current and future protocols can be used. inacceptable for devices, installations or systems in this en-
A universal cabling system consists of three different hierar- vironment.
chical levels: To ensure continuous and trouble-free operation of data
1. The campus backbone cabling connects the campus networks, it is therefore imperative to consider EMC at an
distributor of a building complex to the building distribu- early stage. This does not only affect the data cables of the
tors of the individual buildings. In case of data networks, network, but also the entire electrotechnical infrastructure
50 µm / 125 µm multimode optical fibre cables (in case of of the buildings and building complexes where the entire
distances > 2 km monomode optical fibre cables) with a network should be installed. Consequently, it is important to
maximum length of about 1500 m are mainly used. consider the electromagnetic environmental conditions:

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