Unbundled DSL
Unbundled DSL (also pure DSL , pure DSL , naked DSL , . English : naked DSL , standalone DSL ) called a DSL - broadband access , the unbundled from traditional landline service.
In a more technology-neutral and more general way, one speaks of a pure data connection or unbundled broadband access . This means that, for example, cable internet without an associated cable television subscription is conceptually covered, as is pure cellular- based internet access without an associated cellular voice tariff.
Technical differentiation from conventional private customer DSL
The on -looking residential customers DSL variants were originally from the fixed line operators marketed under the premise that the traditional landline to complete . The frequency spectrum of the telephone line is separated into two areas by means of a splitter ; the fixed network continues to use the lower frequency range of the connection line, while the modulated digital data transmission only uses the previously unused upper frequency ranges.
With unbundled DSL, this line splitting by means of splitters is not necessary and the lower frequency range is either also used for DSL, for example with the xDSL variants traditionally marketed primarily to corporate customers , in which the entire frequency spectrum of the copper twin-core is used ( SDSL ), or is simply idle, if the usual private customer ADSL technology is used, as is common today with most unbundled DSL offers marketed to private customers. An exception in Germany was the SDSL-based Q-DSL-home product line of the provider QSC , which has been addressed to private customers for several years .
Market relevance
Consumer-oriented unbundled DSL in the form of ADSL -based access has been offered on the German market since 2006 on the basis of the fully unbundled subscriber line (for example from HanseNet in the form of the Alice Light product ).
The regulated Standalone - bitstream access provides an unbundled DSL connection of the incumbent operator as a wholesale service for competing telephone companies and Internet service providers is the German Telekom must make available this summer 2008..
Data connection as the basis for fixed network substitution
Unbundled DSL or generally unbundled broadband connections are all the more interesting as more and more participants in classic fixed telephony refrain and instead mobile or without conventional landline - switching technology viable and therefore more cost-effective IP telephony ; use (Voice over IP VoIP).
This migration process is also increasingly being used by traditional landline providers (e.g. HanseNet, Arcor ); their offers based on data connections with IP telephony are referred to as NGN connections .
restrictions
For data connections, telephony is usually implemented using SIP , with the usual data services implemented via the conventional circuit-switched telephone network being only available to a limited extent. For example, ISDN connections emulated via SIP lack the services and features based on fully digital signal transmission, such as data channel , ISDN video telephony , Datex-P and G4 ISDN fax with 64 kB / s. Fax data services based on analog fax modem transmission are restricted depending on the media gateway and codec used . Telephony is no longer possible in the event of a power failure or loss of synchronization on the part of the subscriber .
literature
- Andreas Bluschke, Michael Matthews: xDSL primer. VDE-Verl., Offenbach 2001. ISBN 3-8007-2557-6
- Remco van der Velden: Competition and cooperation on the German DSL market - economics, technology and regulation, Mohr Siebeck Verlag, Tübingen 2007. ISBN 3-1614-9117-3