This communication system was developed to meet the special demands of a large railway company with regard to mobile communication within passenger trains. In addition to voice communication, the possibility to transfer various kinds of messages from sensors and alarm systems was also integrated into the system in order to provide the train personnel and, if required, the operations control centre with reliable, up-to-date information. Thanks to the modular structure, the system can be adapted to meet the various needs of the respective customer.

The telecommunications system is based on DECT technology and can thus be used in multiple countries, without the need to obtain authorisation for the radio frequency.

The train consists of a main car, which contains the DECT base station, and multiple passenger cars, each of which is equipped with a so-called signal module.

Appropriate interfaces are used to connect the base station to the operations control centre of the railway company via GSM or Inmarsat. The signal modules, with an integrated DECT repeater and corresponding DECT handsets, form an integral part of the train car's equipment. These devices register with the base station with the help of an RFID application. This ensures that a car can be exchanged without the need for any complex, system-wide registration procedures.

Signal module functionality consists of:

• System board: records signals received from up to eight error detectors and sensors and creates the voice messages for the operating personnel.
• Disty Repeater plus: forms a DECT radio cell within the car. Thanks to the handover function, it is possible to move between cells without interrupting call connections.
• Intercom terminal with five call buttons: DECT based hands-free telephone for internal system communication with predefined objectives.
• Switch contacts: two integrated relays for controlling external applications.
• Programming/recharging cradle for DECT handsets
• Operating status display per LED
• External, directional aerial installed on the roof of the car: ensures that a DECT connection can be established with the base station in the main car.