A local area network in a telephone network describes a part of the access network that is geographically limited to one or more localities . In countries without national number portability of the subscriber numbers (as in Germany), a local area network comprises all connections that can be reached under the same area code . The boundaries of a local network are generally based on the political city and municipality boundaries that were current at the time the telephone network was established.
A local network consists of:
- a remote peripheral unit (APE) or (in medium-sized locations) a local exchange (OVSt) or (in large locations) an OVSt with several APEs. Each of these facilities is housed in a main distribution center and supplies its own connection area .
- the associated "apron facilities", such as cable distributors and terminal distributors
- the participating institutions
- the lines between these components ( subscriber line )
Small towns usually do not have their own local exchange, but are connected to the next via local cables . The connection is relatively seldom made analog in the low frequency range. Most are remote peripheral units of the nearest local exchange used, the voice channels in PCM - multiplex technology transfer.
As a rule, a local network area covers the areas with a radius of approx. 5 km around the main distributor. There are 5200 local networks in Germany.
The exchanges of different local networks can be connected (meshed ) to one another via local connection lines (OVl) , via which so-called cross traffic takes place between the local networks connected in this way. In digital technology, however, these are no longer bundles of lines, but also PCM multiplex routes.
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