Augsburg Verkehrs GmbH, the public utility company in the Bavarian city of Augsburg, has opted for the most modern SHDSL technology from RAD Data Communications to connect the municipal tramway’s ticket vending machines to an online system.
The idea for the project was spawned by the desire to offer passengers the convenience of paying for their tickets with a debit or credit card.
The first decision that the authorities in Augsburg had to make was to select the appropriate technology, a choice between mobile communications and DSL. A mobile communication solution would have been much more expensive, since the ticket machines would have had to have been linked to the central office over a GSM network using dial-up modems. Given that the city’s public utilities company already owned its own copper and fiber data network, the decision was quickly made in favor of DSL, which required only a one-time investment. In addition, DSL’s permanent online connection makes disruptions controllable and guarantees high transmission reliability. The type of DSL was also chosen quickly. “Due to the long distances that needed to be covered and the high demands made on transmission reliability, SHDSL technology was the only alternative,” explained Marcel Vogl, Pre-Sales Manager at SCALTEL, the local RAD partner that supplied the solution to Augsburg Verkehrs. Another decisive SHDSL advantage is its resistance to the electromagnetic fields that can be produced by the high-tension wires used as the tramway’s overhead lines.
The SHDSL access solution connects 136 ticket machines owned by the city’s public utilities company at the tramway stops via existing copper lines over the company’s own fiber-based Metro Area Network. Up to 18 ticket machines in any one area of the city combine to form eleven cells. RAD’s ASMi-52 SHDSL modem and multiplexer uses a point-to-point DSL line to connect each ticket machine in a cell with a local electric installation. Depending on the distance – a maximum of ten kilometers – a two-wire or four-wire configuration is used. In the street cabinets, a RAD LRS-24 modular modem rack, equipped with ASMi-52 dual/quad modem cards, picks up the DSL lines and forwards the data to an Ethernet switch. The switch then bundles this information and transmits it via a RAD ETX-22 media converter to the core network at the public utility company. RADview SNMP-based graphical element management software enables easy system monitoring as well as performance testing and guarantees high performance reliability.
Due to its undeniable advantages, the RAD solution proved very convincing. “Once the decision was made in favor of an SHDSL solution, SCALTEL convinced us to go with the RAD products and proved to us over a test circuit that this technology was able to satisfy our requirements,” said Ludwig Nerb, head of Electrical Systems at Augsburg Stadtwerke. “It was important for us to have a system that is also able to operate reliably in harsh environments typified by large fluctuations in temperature,” Nerb explained. “This is where the rail version of the ASMi-52, with its solid metal enclosure, scored points, and the rail mounting saves space as well,” he continued. “In addition, the modems adjust to changing transmission characteristics, which provides us with high performance reliability.”
The modems are also easy to operate. Thanks to the RADview management system, they can be configured from the central office. Remote software upgrades are also possible.
“We are very pleased with the successful installation of our solutions by the Augsburg public utilities company,” commented Volker Bendzuweit, General Manager of RAD Data Communications Germany. “A particularly robust infrastructure is very important, especially as far as public transportation is concerned, and we are happy that we were able to demonstrate the reliability of our SHDSL technology.”
