Driving Support System - SSC

A new generation of automatic train protection system that uses μwave technology to transmit signal and track information to the train.

Through its innovative and unique design, it offers safer railway operation, in a cost-effective and timely manner. It continuously monitors the current speed of the train thereby guaranteeing that the maximum speed limit is not violated. In cases where action is required, the system enforce the train's braking system.

Adopted by Italian National Railways on more than 5,000 km of rail lines, SSC brings to regional rail networks the same high level of safety and performance that RFI provides to high-speed and main rail lines.

The system consists of a Wayside Subsystem (SST) and a Onboard Subsystem (SSB):

  • SST transmits information about track and signalling status to the train through a microwave channel operating at approximately 6 GHz
  • SSB receives this information and uses the telegram as the basis for checking whether the train is being driven correctly or not. If the check has a negative result, the system operates emergency braking.

Served Railways
Main & RegionalMain & Regional
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Wayside Subsystem

The SSC wayside subsystem components are installed at each signal of the line side signalled infrastructure. The wayside consists of an encoder and a transponder, both having a very low power consumption so that both signal aspects and power supply are taken directly from signal lamps.

The wayside transmits the signalling status to the train trough a μwave track-train interface. The throughput of this transmission is of 33.3 Kbit/sec, and each message includes a 32 bits Cyclic Redundancy Code to guarantee the required high level of integrity. SSC provides several speed levels, together with the location where their are applicable at each information point (or track to train transmission).

Interlocking LEU
  • Link between the existing fixed lineside signal and the the in-track SSC components (Transponder)
  • Directly acquires aspects from signal lamps
  • Selects the telegram corresponding to the signal aspects
Interlocking LEU
  • Modulates the telegram and transmits it to the on-board equipment over a microwave communication

Onboard Subsystem

SSC onboard subsystem is a fail-safe supervision system with minimal impact on the driver’s behaviour and maximum benefit for the operating railway. It continuously controls that the train is moving with respect to the signalling status it received from the wayside. Otherwise, a warning is given to the driver, and ultimately, braking is enforced if the train driver fails to obey. Train braking is also enforced if a signal showing danger is passed. The SSC Onboard Subsystem also checks that no track to train transmission is missed, using a distance based linking.

European Vital Computer (EVC)
  • Applies the Automatic Train Protection logic
  • Acts as the Interface with the train's main functions (odometry,etc...)
  • Manages the vital functions of the on-board subsystem and provides support for diagnostic maintenance of the on-board subsystem
SSC Antenna
  • Receives telegrams over a microwave communication with wayside subsystem
Man Machine Interface (MMI)
  • LCD touch screen panel to interact with the driver for control and indication functions

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