Branch cables

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Main cable, branch cable and installation cable with 2000, 100 and 6 pairs

A branching cable ( Vzk , also called branching cable ) is a telephone cable that is laid between the cable distributor (usually a switch cabinet at the roadside) and the line termination point (APL, usually the subscriber's house connection). It belongs to network level 3 .

Branch cables in the telephone network

Structure of the subscriber access network

Branch cables are part of the subscriber line . They are usually buried in ground (81%), but can be laid as a cable tube, in cable ducts fed (7%) or in particular in rural areas, as an aerial cable to telephone masts be moved along above ground. The total length of all branch cables laid in Germany is around 720,000 km. They constitute by far the largest part of the telephone network. 90% of all branch lines are less than 500 m in length. This short length is an essential technical feature that enables VDSL to be used almost everywhere in Germany.

Technical condition

Most of the branch cables in the telephone network consist of twisted copper wires. In some areas, especially in eastern Germany, Berlin and Hamburg, there are already many places where fiber optic cables have been laid to individual households ( OPAL ). Because of the ever increasing data transmission rates required , fiber optic technology offers high long-term future potential due to its large bandwidths, despite high installation costs. This is why telephone providers are increasingly laying fiber optic cables to the cable distribution locations.

Branch cables in the cable television network

While branching cables in the telephone network are cables with twin copper wires, sometimes also fiber optic cables , in the cable television network there are coaxial cables in 75-ohm technology. Like the telephone branch cables , they end at the house transfer point , which represents the network termination of the BK-Linientechnik and the transition to the private house distribution system ( network level 4 ).

See also

Individual evidence

  1. ↑ Handbook of Telecommunications Technology, Basic Series Volume 7 Line Technology, as of 1980, p. 19
  2. ↑ Access networks for telecommunications, Hanser, p. 63
  3. ↑ http://www.ftd.de/technik/it_telekommunikation/:Arcor%20VDSL%20Netz/279358.html ( Memento from November 17, 2007 in the Internet Archive )