Matterhorn Gotthard Bahn has chosen a KEYMILE solution to control and monitor radio and data connections between the signal boxes in its railway network. A key proviso was that the products used had to comply with all the stringent safety requirements established by the Swiss Office of Transport.

Because Matterhorn Gotthard Bahn has constantly enhanced its operations, the past few years have seen a steady rise in demand for automation and consequently remote control of signal boxes. As a result products are required to comply with all the regulations stipulated by the regulatory authority, which in Switzerland’s case is the Federal Office of Transport (FOT).

For its complex telephony, radio and data connections, Matterhorn Gotthard Bahn uses the UMUX platform made by KEYMILE, one of the leading manufacturers of next-generation data transmission systems.

UMUX is a multi-service access system that provides comprehensive data services. A central network management system actively monitors all UMUX systems used. As a result, any malfunction can be quickly localised. If additional support is required, the KEYMILE support can use remote support access to the local network management system.

At the end of 2008 planning started to provide fibre-optic links between the signal boxes and the appropriate integrated control and information system (ILTIS) managed by UMUX. ILTIS R40, the current release, is based solely on IP connections: each signal box is connected with two 4Mbps point-to-point Ethernet lines and the paths are protected by a redundant path.

Should a malfunction occur, because the fibre optics have ruptured for example, a switch is made to the second path in milliseconds. European standard EN 50159-1 directives stipulating a closed data transmission network for these types of connections must be adhered to. In this case an essential consideration is a lack of interference. It must be shown that adjacent data lines do not have any impact on the ILTIS connections.

KEYMILE operates this application with proven, robust synchronous digital hierarchy (SDH) technology. Via a circuit-switched leased line the paths are implemented with two 2Mbps (two VC-12s per connection). In addition to the SDH interfaces, the board used also has four Ethernet ports (10/100/1000BaseT) that are switched using Ethernet-over-SDH technology to SDH. Therefore neither routers nor switches are present on the connections (which in some cases are more than 100km long) and the requirements for lack of interference are fulfilled entirely.

An additional challenge the network faced was the restricted space for fibre-optics in the Furka tunnel. For the main path and the second path, only one fibre-optic each was available. Another difficulty was that a single section of track is more than 40km long. To bridge this section STM-4 data transmission with powerful small factor pluggable (SFP) modules was implemented that enabled sending and receiving via a single fibre-optic line.

At the end of last year the new solution was commissioned for controlling radio and data connections between the signal boxes. It has been working perfectly since that time. Matterhorn Gotthard Bahn is convinced it has made a wise long-term investment. In the next few years the railway company will continually convert to more remote-controlled signal boxes. As a result, more stations can be integrated with little outlay.