Main cable
The main cable ( Hk ) in the Deutsche Telekom telephone network is used, starting from the exchange , to supply large -area telecommunications connections (e.g. telephone connections ) in a spatially limited area as a connection to the network node. It is part of the subscriber line and connects the main distributor with the cable distributors , from which the branch cables are laid to the individual households.
construction
The main cable is a telephone cable with a large number (up to 2000) of stranded copper wire pairs in a PE sheath (previously also with lead sheath) with a round cross-section. It is laid over distances of several kilometers. Up to the middle of the 1990s, main cables with a core diameter of 0.4 mm were mostly laid up to 3.5 km, as well as those with 0.6 mm and 0.8 mm core diameter. Then the diameter was generally reduced from 0.4 mm to 0.35 or from 0.6 mm to 0.5 mm. That was irrelevant for pure telephone traffic and saved costs. This is why the term "cost-minimized cable" was also used. With the introduction of DSL technology, the 0.35 was dispensed with and only 0.5 (standard) and 0.8 diameter (less common, depending on the range) were used, so that the HK network today often consists of several sections with different wire diameters consists.
In contrast to the generally petrolatum-filled junction cables, the main cable is unfilled. The reason for this is the permanent compressed air monitoring. In the event of damage, the fault can be easily located. Filled HK is only used in rural areas with APEn , as compressed air monitoring is not required here.
Shape of the main cable network
The task of the main cable is to feed a certain line capacity (copper wire pairs) to one or more regions located in a logical line, such as residential areas, commercial properties or company premises. The subscriber access network is structured like a tree. The main cable forms the trunk feed to the respective cable distributor, which branches off a certain number of twin wires from it. The core capacity is therefore greatest at the beginning of the trunk and decreases with increasing length. The length of the respective continuous main cable is limited by physical conditions (copper wire cross-section in relation to the cable length of the twin wires). In the exchange, the outside of the are cable distributors coming multi-pair main cable in the "Cable Distribution area" of the exchange (usually in the basement) means " division sleeves split" into smaller inner cord and out to the main distribution. In the 1990s, the construction method changed to a sleeveless division. Here the HK was only stripped and the individual bundles of the cable were sheathed with "zipper hose" and continued to the vertical side of the HVt.
Transition to the branching cable network
The cable distributors connected to the main cables then supply the buildings and properties in the surrounding region or streets directly to the respective structures via the branch cables. The connections operated at the end of each branch cable must under normal circumstances fulfill their assigned basic function, the operation of a telephone connection. The use of a certain feature such as B. ADSL does not initially have to be guaranteed.
Individual evidence
Web links
- "Analytical cost model access network" www.bundesnetzagentur.de (PDF file; 420 kB)