ATLAS™ 100 is a spot transmission based train control system to be used as an overlay on an underlying signaling system with fixed block operation.
It incorporates ALSTOM's ICONIS™ control centre, SMARTLOCK™ interlocking and SMARTWAY™ conventional signaling products.
In ATLAS™ 100, movement authorities are generated trackside and transmitted to the train via Eurobalises. Train detection and integrity supervision are performed by the trackside equipment.

Euroloop can be used to provide semi-continuous infill in ATLAS™ 100. This gives better performance as revised authority to pass the signal can be received before reaching the end of the movement authority.

	Interoperable
	Speeds up to 500 km/h
	ATP function
	Upgradeable to ATLAS™ 200 and ATLAS™ 300

	Reception of movement authority and track characteristics,
	static speed pro-files and distances related to the transmitting balise
	Selection of the most restrictive value of the different speeds permitted at each location ahead
	Calculation of dynamic speed profile, taking into account the train running characteristics which are known on-board
	Comparison of the actual train speed with the permitted speed and application of the brakes if necessary
	Cab signaling to the driver
	Main Trackside Functions

	IDetermine movement authority according to the underlying signaling system
	Transmit movement authorities and infrastructure data to the train
	Interlocking to control trackside equipment like points and signals
	Control Centre for the management of the network

Interoperability with existing train control and supervision systems is achieved with the STM. The STM allows a train equipped with the ERTMS to run on existing ATP systems. There are currently over 10 such systems in Europe. They include the KVB, TBL, ATBL and BACC from ALSTOM.