17 December 2002 -- Telekommunikation Lindau GmbH, the local operator in the German town of Lindau is to deploy solutions developed by RAD Data Communications in a new high speed, citywide data communications network.
The interesting feature of the new Gigabit Ethernet network is its original copper-based backbone, which will gradually be replaced with fibre optic cable. The core of the solution is DSL technology, which significantly increases the transmission capacity of copper lines to produce sufficient bandwidth.
The high cost of doing excavation work in Lindau's historic city centre and the inevitable disruption this would cause to traffic and tourism ruled out the "classic" approach to building a new network, which would involve burying several kilometres of fibre optic cables underground. To overcome this obstacle, Scaltel AG, a RAD Data Communications distributor in Germany, proposed a plan that incorporates the existing copper network.
Five hundred kilometres in length, the copper cable network was originally laid by the Stadtwerke utility next to power, gas and water lines for remote monitoring and control applications.
Scaltel's cost-effective plan calls for gradual migration to fibre optic lines in the network's core, with three computer centres to be built connected by copper twisted pair. To cope with the heavy transmission requirements demanded by high-speed communications, however, a way had to be found to significantly boost available bandwidth.
RAD's HTU-E1 series modems increase the transmission speed of each copper twisted pair up to 2Mbit/s. The high-speed modems also support transmission over distances of up to 4km without the need for any repeaters. The backbone consists of several multiplexed lines between the various computer centres that provide the required bandwidth for most applications.
"The Lindau example proves that, despite falling prices for lines and equipment, fibre optic is not always the most economical solution for the transport network," explains Volker Bendzuweit, Managing Director of RAD Germany. "Whenever the installation costs for new lines appear prohibitive, RAD's DSL technology can offer a sound alternative, since it is capable of using the existing copper infrastructure," he adds.