Broadband switching network
The forerunner broadband network or switching broadband network ( VBN ) in Germany referred to a fiber optic overlay network with subscriber self-selection for telecommunications .
The project was started in 1986 with the aim of establishing a video conferencing service in Germany. It was in regular operation from 1989. In 1991/1992 the VBN linked a total of 29 subnets with 500 participants across Germany. A bit rate of 140 Mbit / s, composed of a PCM -coded video signal and a few additional channels, was switched through. For connection to this network, the subscriber received a subscriber connection device (TAE) which contained the video codec . The subscriber interface of the TAE required a 5 MHz FBAS signal.
The high bit rate of 140 Mbit / s made the VBN attractive for universities and research institutions, which immediately began to exchange large amounts of data of all kinds. As a result, the VBN quickly became uneconomical because of the fees that were based on the data volume for video conferences. As a result, the video conference services were transferred to a 2 Mbit / s network and ISDN , before the VBN was switched off. At times, the German television stations still used the VBN for image transmission. However, they were then transferred to the German ATM network.
A comparable specification called Connectionless Broadband Data Service (CBDS) has been adopted by ETSI across Europe .
Individual evidence
- ↑ Gerd Siegmund: Technology of the networks. 5th edition, Hüthig, Heidelberg 2002, ISBN 3-8266-5021-2 . P. 45
literature
- Peter Bocker: ISDN . Digital networks for voice, text, data, video and multimedia communications; 4th edition, Springer Verlag, Berlin / Heidelberg 1997, ISBN 3-642-64360-4 , pp. 34-37.
See also
Web links
- IT Knowledge VBN (Mediating Broadband Network) (accessed on March 29, 2018)