This is an example lexicon
Ceci est un exemple de lexique
APN
implicit-from-entry-label: Access Point Name
Access Point Name
ACKNOWLEDGEMENT, DRIVER
Confirmation by the driver that he/she has taken into account information received through the DMI
ACK
Confirmation by an entity that it has received information
ACKNOWLEDGEMENT
ALE
implicit-from-entry-label: Adaptation & redundancy management Layer Entity
Adaptation & redundancy management Layer Entity
AIRGAP LANGUAGE
The ERTMS/ETCS application data, together with its harmonised rules, which is transmitted over the balise, loop and radio transmission media.
AIRGAP
The set of interfaces between track and train. It is composed of the Eurobalise, the Euroloop and the Euroradio interfaces.
APPLICATION LEVEL
The different ERTMS/ETCS application levels are a way to express the possible operating relationships between track and train. Level definitions are related to the trackside equipment used, to the way the trackside information reaches the on-board units and to which functions are processed in the trackside and in the on-board equipment respectively.
KMAC
Cryptographic key (KMAC) used to establish a safe connection according to the EURORADIO protocol.
AUTHENTICATION KEY
AUTHENTICATION
The process of determining whether someone or something is who or what it is declared to be.
ATC
implicit-from-entry-label: Automatic Train Control
Automatic Train Control
ATO
implicit-from-entry-label: Automatic Train Operation
Automatic Train Operation
ATP
A safety system that enforces either compliance with or observation of speed restrictions and signal aspects by trains.
AUTOMATIC TRAIN PROTECTION
AVAILABILITY
The ability of a product to be in a state to perform a required function under given conditions at a given instant in time or over a given time interval assuming that the required external resources are provided. (3) Definitions for other availability related terms are given in reference 3
ASP
implicit-from-entry-label: Axle Load speed Profile
Axle Load speed Profile
BALISE, FIXED
A balise that transmits data that does not change dynamically according to signalling information.
BALISE GROUP LOCATION REFERENCE
Location of balise number 1 in a balise group. It is the origin of the balise group coordinate system
BALISE GROUP
One or more balises which are treated as having the same reference location on the track. The telegrams transmitted by all the balises of a group form a track-to-train message.
BALISE, SWITCHABLE
A balise that transmits data that can change dynamically according to signalling information.
BTM
A module inside the ERTMS/ETCS on-board equipment for intermittent transmission between track and train, which processes Up-link signals and retrieves application data telegrams from a balise.
BALISE TRANSMISSION MODULE
BALISE
A passive transponder mounted on the track which can communicate with a train passing over it.
BASELINE RELEASE
A baseline release is defined by a specific version of each of the CCS TSI annex A documents that are relevant for the system
BASELINE
A baseline is defined by a stable kernel in terms of system functionality, performance and other non-functional characteristics.
BCD
implicit-from-entry-label: Binary Coded Decimal
Binary Coded Decimal
BLOCK
A method of controlling the separation between trains by dividing the line into sections with, normally, no more than one train in each section. The block can either be a fixed block or a moving block.
BRAKING CURVE
Prediction of the train speed decrease versus distance by the ERTMS/ETCS on-board equipment, from a mathematical model of the train braking dynamics and of the track characteristics ahead.
BRAKING DISTANCE, EMERGENCY
The distance in which a train is capable of stopping with the emergency brake applied. Dependent upon train speed, train type, braking characteristics, train weight and gradient.
BRAKING DISTANCE, SERVICE
The distance in which a train is capable of stopping, with the full service brake applied. Dependent upon train speed, train type, braking characteristics, train weight and gradient.
CAB, ACTIVE
The active cab is the cab associated with an ERTMS/ETCS on- board equipment, from which the traction is controlled
CAB
The space in the power unit or driving unit of the train containing the operating controls and providing shelter and seats for the driver or engine crew.
CSM
implicit-from-entry-label: Ceiling Speed Monitoring
Ceiling Speed Monitoring
CLEAR (A SIGNAL)
To change a signal aspect from its most restrictive aspect to a less restrictive aspect.
CEN
implicit-from-entry-label: Comité Européen de Normalisation
Comité Européen de Normalisation
COMMON-MODE FAULT
Fault common to items which are intended to be independent.
CER
implicit-from-entry-label: Community of European Railways
Community of European Railways
CONDITIONAL LEVEL TRANSITION ORDER
A Conditional Level Transition Order is a spot check of the on- board operated level. This may cause a level transition if the ERTMS/ETCS on-board does not operate one of the allowed levels.
CONDITIONS, MAINTENANCE
The maintenance criteria adopted for maintaining the system referred to its Operating Conditions.
CONDITIONS, OPERATING
The rated performance required of the system.
CONDITIONS, SYSTEM
The conditions under which the system is called to operate, including:  environmental conditions;  operating conditions;  maintenance conditions.
CONFIGURATION MANAGEMENT
A discipline applying technical and administrative direction and surveillance to identify and document the functional and physical characteristics of a configuration item, control change to those characteristics, record and report change processing and implementation status and verify compliance with specified requirements. (3)
CONFIGURATION
The structuring and interconnecting of the hardware and software of a system for its intended application.
CONFLICTING MOVEMENTS
Movements that would require trains to occupy the same portion of track over all or part of their length.
CONTACT LENGTH
The distance between the place where a train becomes able to communicate with a device (e.g. a balise) to the place where communication becomes impossible.
CONTINOUS DATA TRANSMISSION
Track-to-train or train-to-track transmission that can take place continuously, independent of location (e.g. by radio).
CONTROL CENTRE
A centralised control system that controls the train movements in a large territory.
CRITICALITY
The point at which a failure or a number of failures renders the system unusable and/or unsafe.
CROSS-ACCEPTANCE
The status achieved by a product that has been accepted by one Authority to the relevant European Standards and is acceptable to other Authorities without the necessity for further assessment. (4)
CURRENT POSITION
The position of a train measured at a certain moment using defined system co-ordinates.
CRC
implicit-from-entry-label: Cyclic Redundancy Code
Cyclic Redundancy Code
DANGER (ASPECT)
An indication given by a signal to stop.
The location beyond the End of Movement Authority that can be reached by the front of the train without creating a hazardous situation.
DANGER POINT
DATA INTEGRITY
The property that a message has not been modified or destroyed.
DECELERATION DATA
Data that relates to the braking performance of the train.
DEFAULT VALUE
Value stored in the ERTMS/ETCS on-board equipment and used if there is no other value available.
DESK
Inside a cab, the set of operating controls, which is dedicated to preferred movements in a given direction (i.e. forward movements, in which visibility from the cab is provided to the driver). Exception: some single cab locomotives are fitted with one single desk, allowing normal movements in both directions.
implicit-from-entry-label: Difference Value between the Permitted Speed to e.g. DV_EBIminEmergency Brake Intervention speed (minimum) DV_EBImax Emergency Brake Intervention speed (maximum)
Difference Value between the Permitted Speed to e.g. DV_EBIminEmergency Brake Intervention speed (minimum) DV_EBImax Emergency Brake Intervention speed (maximum)
DIVERSITY
A means of achieving all or part of the specified requirements in more than one independent and dissimilar manner. (4)
DNS
implicit-from-entry-label: Domain Name Server
Domain Name Server
DRIVER IDENTITY
Unique code which identifies a train driver.
DMI
The interface to enable direct communication between the ERTMS/ETCS on-board equipment and the driver.
DRIVER MACHINE INTERFACE
DRIVING ON SIGHT
The driver driving at a speed that allows him to stop the train to avoid obstacles on the track.
DUAL CAB ENGINE
Rolling Stock unit fitted with two driving cabs and one single ERTMS/ETCS on-board equipment.
DYNAMIC SPEED PROFILE
The speed / distance profile that a train may follow without violating the static speed profile and/or the EOA/LOA.
EMC
implicit-from-entry-label: Electromagnetic Compatibility
Electromagnetic Compatibility
EMI
implicit-from-entry-label: Electromagnetic Interference
Electromagnetic Interference
EBCL
implicit-from-entry-label: Emergency Brake Confidence Level
Emergency Brake Confidence Level
EBD
implicit-from-entry-label: Emergency Brake Deceleration Curve
Emergency Brake Deceleration Curve
EBI
implicit-from-entry-label: Emergency Brake Intervention supervision limit
Emergency Brake Intervention supervision limit
Application of a predefined brake force in the shortest time in order to stop the train with a defined level of brake performance.
EMERGENCY BRAKING
EOA
Location to which the train is permitted to proceed and where target speed = zero.
END OF AUTHORITY
END OF LOOP MARKER
The balise group intended to define where a “loop” begins or ends.
END OF MOVEMENT AUTHORITY
Location to which the train is permitted to proceed according to an MA. When transmitting an MA, it is the end of the last section given in the MA.
EOLM
implicit-from-entry-label: End-of-Loop-Marker
End-of-Loop-Marker
ENGINE
Association of one or two driving cab(s) of a Rolling Stock unit with one single ERTMS/ETCS on-board equipment. When a driving cab of the engine is used to lead a train/shunting consist, the ERTMS/ETCS on-board equipment supervises the movement of the train/shunting consist the engine belongs to. Each driving cab of an engine allows the driver communicating with the ERTMS/ETCS on-board equipment through the DMI.
ENTRANCE SIGNAL
A main signal, intended for trains entering a station.
EQUIPPED LINE
Line equipped with ERTMS/ ETCS in application level 1, 2 or 3
ERTMS/ETCS ON-BOARD EQUIPMENT
The part (software and/or hardware) of the on-board equipment, which fulfils the ERTMS/ETCS specification.
ESTIMATED POSITION
The position the ERTMS/ETCS on-board equipment estimates the train front is at, with the highest probability according to the physical characteristics of the train and to the odometer working conditions. It is expressed as a distance from a location reference detected by the on-board.
ESTIMATED SPEED
The speed the odometer estimates the train is running at, with the highest probability according to the physical characteristics of the train and to the odometer working conditions
ETCS ID
The ETCS identity of an on-board equipment is made of a single identity number. The ETCS identity of an RBC, balise group, loop or RIU is composed of a country/region identity number and of an identity number within the country/region.
ETCS IDENTITY
EUROBALISE
Balise compliant with the ERTMS/ETCS specification.
EUROLOOP
Loop compliant with the ERTMS/ETCS specification.
implicit-from-entry-label: European Commission
European Commission
CENELEC
implicit-from-entry-label: European Committee for Electrotechnical Standardisation (Comité Européen de Normalisation Electrotechnique)
European Committee for Electrotechnical Standardisation (Comité Européen de Normalisation Electrotechnique)
EEIG
implicit-from-entry-label: European Economic Interest Group.
European Economic Interest Group.
EIRENE
implicit-from-entry-label: European Integrated Radio Enhanced Network
European Integrated Radio Enhanced Network
implicit-from-entry-label: European Norm
European Norm
ERTMS
Signalling and operation management system encompassing ETCS for the Control Command and GSM-R for voice and data communication. GSM-R is used as radio bearer for ETCS.
EUROPEAN RAIL TRAFFIC MANAGEMENT SYSTEM
ERA
implicit-from-entry-label: European Railway Agency
European Railway Agency
ETSI
implicit-from-entry-label: European Telecommunications Standards Institute
European Telecommunications Standards Institute
ETCS
The Control Command part of ERTMS.
EUROPEAN TRAIN CONTROL SYSTEM
implicit-from-entry-label: European Union
European Union
EVC
implicit-from-entry-label: European Vital Computer
European Vital Computer
EURORADIO
The functions required, including the message protocols, to provide an acceptably safe communications channel between ERTMS/ETCS trackside and ERTMS/ETCS on-board equipment over an open radio network
EXIT SIGNAL
A main signal that is intended for trains leaving a station.
EXPECTATION WINDOW
The interval between the outer limits to accept a balise group.
FAIL-SAFE
A design philosophy which results in any expected failure maintaining or placing the equipment in a safe state.
FMEA
implicit-from-entry-label: Failure Mode and Effects Analysis
Failure Mode and Effects Analysis
FMECA
implicit-from-entry-label: Failure Mode, Effect and Criticality Analysis
Failure Mode, Effect and Criticality Analysis
FAILURE
Effect of an error on the intended service.
FAULT DETECTION TIME
Time span that begins at the instant when a fault occurs and ends when the existence of the fault is detected.
FAULT NEGATION TIME
Time span that begins when the existence of a fault is detected and ends when a safe state is enforced.
FAULT
An abnormal condition that could lead to an error in a system. A fault can be random or systematic. (4)
FIXED BLOCK
A block in which the extremities of the block sections are at fixed locations. The signalling allows a train to move from one block to the next, normally only when the block ahead is clear.
FFFIS
implicit-from-entry-label: Form-Fit Functional Interface Specification
Form-Fit Functional Interface Specification
FFFS
implicit-from-entry-label: Form-Fit Functional Specification
Form-Fit Functional Specification
FOULING POINT
The place where a vehicle standing on a converging line would come into contact with a vehicle on the other line.
ERTMS/ETCS on-board equipment mode giving full protection against overspeed and overrun.
FULL SUPERVISION MODE
FIS
implicit-from-entry-label: Functional Interface Specification
Functional Interface Specification
FRS
implicit-from-entry-label: Functional Requirements Specification
Functional Requirements Specification
GPRS
implicit-from-entry-label: General Packet Radio Service
General Packet Radio Service
GSM-R
implicit-from-entry-label: Global System for Mobile Communications – Railways
Global System for Mobile Communications – Railways
GSM
implicit-from-entry-label: Global System for Mobile Communications
Global System for Mobile Communications
GUI
implicit-from-entry-label: Guidance curve
Guidance curve
HOME KMC
The KMC in a KM domain to which trackside and on-board entities belonging to that domain refer for key management.
I&A
implicit-from-entry-label: Identification and Authentication
Identification and Authentication
IMMEDIATE LEVEL TRANSITION ORDER
An Immediate Level Transition Order means both a level transition ordered “now” and a level transition ordered at null distance not in relation with in-fill.
IN ADVANCE OF IN REAR OF
A term indicating a point beyond a specific location on the track, with respect to a given direction. A term indicating a point on the approach to a specific location on the track, with respect to a given direction. in rear ofin advance of Specific location
INDEPENDENCE, TECHNICAL
Freedom from any mechanism which can affect the correct operation of more than one item.
implicit-from-entry-label: Indication supervision limit
Indication supervision limit
INFILL INFORMATION
Trackside data, referred to a main signal, which is transmitted at locations in rear of the main signal. Provides, for example, the ability to inform a train that the signal ahead has cleared.
INFILL LOOP
A loop which is installed at a place (e.g. in rear of a signal) to avoid unnecessary delay by transmitting in fill information advising the train at once when the signal ahead clears.
INFORMATION POINT
Specific location on the track where information can be transmitted from ERTMS/ETCS trackside to ERTMS/ETCS on- board equipment (see also SPOT TRANSMISSION)
INTERLOCKING
A general term applied to the controlling of the setting and releasing of “signals” and “points” to prevent unsafe conditions arising, and equipment which performs this function.
INTERMITTENT TRANSMISSION
A term that encompasses “SPOT TRANSMISSION” and “SEMI- CONTINUOUS TRANSMISSION”.
IEC
implicit-from-entry-label: International Electro-technical Commission
International Electro-technical Commission
ISO
implicit-from-entry-label: International Standardisation Organisation
International Standardisation Organisation
implicit-from-entry-label: Internet Protocol
Internet Protocol
INTEROPERABILITY CONSTITUENT
Any elementary component, group of components, subassembly or complete assembly of equipment incorporated or intended to be incorporated into a subsystem, upon which the interoperability of the rail system depends either directly or indirectly. The concept of a constituent covers both tangible objects and intangible objects such as software. (1)
INTEROPERABILITY, OPERATIONAL
The set of harmonised operating rules that enables interoperability.
INTEROPERABILITY, TECHNICAL
The set of harmonised technical requirements that enables interoperability. The ERTMS/ETCS specification defines the requirements for technical interoperability.
INTEROPERABILITY
Interoperabilitymeanstheabilitytoallowthesafeand uninterrupted movement of trains that accomplish the specified levels of performance. (1)
INTERVENTION
Where ERTMS/ETCS takes control from the driver by cutting traction power or applying the full service brake and cutting traction power or applying the emergency brake and cutting traction power.
When the ERTMS/ETCS on-board equipment is disconnected from the vehicle braking system. Isolation is indicated to the driver.
ISOLATION MODE
JURIDICAL DATA
Data to record all actions and exchanges relating to the movement of trains sufficient for off line analysis of all events leading to an incident.
KERNEL
The core of the ERTMS/ETCS on-board equipment.
KMC
The entity responsible for key management functions in a KM domain.
KEY MANAGEMENT CENTRE
KMS
The set of entities and operational procedures taking part in the key distribution system.
KEY MANAGEMENT SYSTEM
The generation, storage, secure distribution, deletion, archiving and application of key entries in accordance with the security policy in a KM domain.
KEY MANAGEMENT
KEY VALIDITY PERIOD
The specific timespan during which a key is valid.
KEY
A predefined component or information necessary to be able to encrypt data or interpret encrypted data.
KM DOMAIN
One KMC (Home KMC) and all the on-boards, RBCs and RIUs using that KMC for key management purposes.
KER
implicit-from-entry-label: KVB, Ebicab, RSDD
KVB, Ebicab, RSDD
LRBG
The LRBG is used as a common location reference between the ERTMS/ETCS on-board and trackside equipments in levels 2 & 3
LAST RELEVANT BALISE GROUP
LEADING ENGINE
The engine in which a driving cab is used to control the movement of a train/shunting consist, under the supervision of the ERTMS/ETCS on-board equipment associated with the driving cab.
LEVEL 0 AREA
Trackside area in which level 0 operation is supported.
LEVEL 0
A level of ERTMS/ETCS defined to cover instances when the ERTMS/ETCS on-board equipment is operating in an area where the trackside is neither fitted with operational ERTMS/ETCS equipment nor fitted with operational National System
LEVEL 1 AREA
Trackside area in which level 1 operation is supported.
LEVEL 1
A level of ERTMS/ETCS overlaid onto conventional line side signalling that uses Eurobalises / Euroloop / Radio Infill to pass movement authorities to the train whilst relying on conventional means to determine train position and integrity.
LEVEL 2 AREA
Trackside area in which level 2 operation is supported.
LEVEL 2/3 AREA
Trackside area in which level 2 and/or level 3 operation is supported.
LEVEL 2
A level of ERTMS/ETCS that uses radio to pass movement authorities to the train whilst relying on trackside conventional means to determine train position and integrity.
LEVEL 3 AREA
Trackside area in which level 3 operation is supported.
LEVEL 3
A level of ERTMS/ETCS that uses radio to pass movement authorities to the train. Level 3 uses train reported position and integrity to determine if it is safe to issue the movement authority.
implicit-from-entry-label: Level crossing
Level crossing
LEVEL NTC AREA
Trackside area in which level NTC operation is supported.
LEVEL NTC
A level of ERTMS/ETCS that allows the supervision of the train with an existing National Train Control system.
LEVEL TRANSITION ANNOUNCEMENT
A Level Transition Announcement means both a level transition ordered for a further location and a level transition ordered at null distance transmitted as in-fill information
LEVEL TRANSITION BORDER
A location where the list of levels supported by the trackside changes.
LEVEL TRANSITION INFORMATION
This term is used for both Level Transition Order and Conditional Level Transition Order.
LEVEL TRANSITION ORDER
This term is used for both Immediate Level Transition Order and Level Transition Announcement.
LEVEL
Contracted form of APPLICATION LEVEL
LIFECYCLE COST (SYSTEM)
The sum of the costs sustained or to be sustained for performing and appropriately supporting the activities occurring in the context of the operational parts of the System Lifecycle.
LIFECYCLE (SYSTEM)
The activities occurring during a period of time that starts when a system is conceived and ends at decommissioning when the system is no longer available for use. (See Reference 3)
LOA
The place beyond which the train has no information but to which the train is authorised to run with a defined target speed higher than zero. The train is expected to receive new information before passing the Limit of Authority.
LIMIT OF AUTHORITY
ERTMS/ETCS on-board equipment mode giving partial protection against over speed and over run. The driver has to observe and obey to line side signals and operating rules when in limited supervision mode.
LIMITED SUPERVISION MODE
LEU
A device for communicating variable signalling data to switchable balises.
LINE SIDE ELECTRONIC UNIT
LINE SIDE EQUIPMENT
see Trackside Equipment.
LUC
implicit-from-entry-label: Line Under Construction
Line Under Construction
LINE
A continuous section of railway track.
LINKING DISTANCE
The distance between announced balise groups.
LINKING INFORMATION
Data defining the distance between groups of balises, their identity and orientation, and the action to be taken if an announced balise group is not detected within given limits (EXPECTATION WINDOW).
LINKING
A functionality to protect against missing data from BALISE GROUPS by announcing them in advance through LINKING INFORMATION and by checking whether they have been read within a certain EXPECTATION WINDOW
LOCAL TIME
The time for ordinary transactions in a locality, which is likely to be shown on station clocks.
LOOP MESSAGE FORMAT
The format for transmitting data by a loop.
LTM
A module (inside the ERTMS/ETCS on-board equipment), which retrieves application data from a loop.
LOOP TRANSMISSION MODULE
LOOP
Track mounted device for the transmission of data between track- to-train within a defined area.
LSSMA
implicit-from-entry-label: Lowest Supervised Speed within the Movement Authority
Lowest Supervised Speed within the Movement Authority
MAIN SIGNAL
A fixed signal intended for train movements capable of showing a ‘danger aspect’ and one or more ‘proceed aspects’. In some cases main signals at danger are valid for shunt movements.
MAINTAINABILITY
The probability that a given active maintenance action, for an item under given conditions of use can be carried out within a stated time interval when the maintenance is performed under stated conditions and using stated procedures and resources. (3) (Definitions for other maintenance related terms are given in reference 3).
MALFUNCTION
A deviation from the specified performance causing the system to work incorrectly. This is normally due to an error or fault in the system.
MANDATORY
When it is compulsory to fulfil and to implement a requirement to realise a technically interoperable standard for the ERTMS/ETCS equipment or system.
MANUAL LEVEL CHANGE
Level transition initiated by the driver.
MAX SAFE FRONT END
The maximum safe front end position differs from the estimated position by the Under-reading Amount in the distance measured from the LRBG plus the Location Accuracy of the LRBG
MAY
Is permissible.
MTBF
implicit-from-entry-label: Mean Time Between Failure
Mean Time Between Failure
MESSAGE AUTHENTICATION CODE (MAC)
Code to provide data origin authentication and data integrity.
MAC
implicit-from-entry-label: Message Authentication Code
Message Authentication Code
MESSAGE
The combination of application data and protocol data that is transmitted by balise group, loop or radio to a train or from the train to trackside by radio.
MIN SAFE FRONT END
The minimum safe front end position differs from the estimated position by the Over-reading Amount in the distance measured from the LRBG plus the Location Accuracy of the LRBG
MINOR FAILURE
see Failure, Minor
MISSION, ETCS
Any train movement started under the supervision of an ERTMS/ETCS on-board equipment in one the following modes: FS, LS, SR, OS, NL, UN, or SN. The ETCS mission is ended when any of the following modes is entered: SB, SH
MISSION
An objective description of the fundamental task to be performed by a system. (3)
MORANE
implicit-from-entry-label: Mobile Radio for Railway Networks in Europe
Mobile Radio for Railway Networks in Europe
MODE
An operating state of the ERTMS/ETCS on-board equipment with a specified split of operational responsibilities between the ERTMS/ETCS system and the driver.
MRDT
implicit-from-entry-label: Most Relevant Displayed Target
Most Relevant Displayed Target
MRSP
The speed which a train must not exceed. It is the lowest speed taking into account all the various speed profiles.
MOST RESTRICTIVE SPEED PROFILE
Permission for a train to run to a specific location within the constraints of the infrastructure.
MOVEMENT AUTHORITY
MOVING BLOCK
A block whose length is defined by the position of the train occupying the section of track ahead. The minimum block length would be from the rear most part of the occupying train to a point on the track where, if the train braked from its current speed, the front of the occupying train would be when the train came to a stand.
NATIONAL SYSTEM MODE
ERTMS/ETCS on-board equipment mode in which the supervision of the train is ensured by a National System.
NATIONAL TRAIN CONTROL SYSTEM
A previously installed train control system defined as Class B system in CCS TSI.
NTC
implicit-from-entry-label: National Train Control
National Train Control
NATIONAL VALUES
Values that are transmitted to a train when entering the infrastructure of an administration related to rules and regulations of that administration. National values may be changed within an administrations area.
ERTMS/ETCS on-board equipment mode in which the on-board equipment is not powered and the emergency brake is commanded.
NO POWER MODE
implicit-from-entry-label: Non Leading mode
Non Leading mode
NON-EQUIPPED LINE
A line without operational trackside Automatic Train Protection system.
NON-LEADING MODE
ERTMS/ETCS on-board equipment mode when it is connected to an active cab which is not in the leading engine of the train.
NON-VITAL
A description applied to those parts of the signalling system whose failure or non-availability does not directly endanger rail traffic or reduce the integrity of the signalling system.
OCCUPIED
A track section having any part of a train present upon it.
ODOMETER ACCURACY
The extent to which the odometer might make underestimation/overestimation in measuring the movement of the train.
ODOMETRY REFERENCE LOCATION
The reference location to which refers the train based odometer distance reading.
ODOMETRY
The process of measuring the train’s movement along the track. Used for speed measurement and distance measurement.
OFF-LINE KMS
KMS where distribution, deletion or updating of key entries requires staff intervention on the target device.
ERTMS/ETCS on-board equipment mode that gives the driver partial responsibility for the safe control of his train. In this mode the train possesses a movement authority but the track ahead might be occupied by another train.
ON SIGHT MODE
ON-BOARD EQUIPMENT
The equipment carried on the train with the aim of supervising vehicle operation.
ON-BOARD RECORDING DEVICE
A device (outside the ERTMS/ETCS on-board equipment) that records and stores data for subsequent analysis (e.g. further to a train accident).
OBU
See ERTMS/ETCS ON-BOARD EQUIPMENT.
ON-BOARD UNIT
ON-LINE KMS
KMS allowing remote distribution, deletion or updating of key entries in the target device.
OPERATED SYSTEM VERSION
For both trackside and on-board, to operate a system version means to comply with the requirements from all TSI annex A documents, which are applicable to this system version and to the concerned subsystem. The operated system version is ordered by trackside; however, to operate a system version number X within a delimited trackside area only means that an on-board equipment running on this area shall behave according to the set of requirements applicable to the system version number X.Y where X is the one ordered by trackside and Y is the system version number Y (which may be different from the one ordered by trackside) operated by the on-board within this version X.
OVER-READING AMOUNT
The distance the train may have travelled less far than the estimated position. The distance is estimated by the ERTMS/ETCS on-board equipment taking into account the odometer inaccuracy plus the error for the detection of a balise location, as defined in the Eurobalise specifications.
The section of line in advance of a stop signal that must be unoccupied and, where necessary, locked before and during a signalled running movement to the rear of the signal to avoid an accident if the train brakes do not perform as well as expected and the train passes the END OF MOVEMENT AUTHORITY.
OVERLAP
PACKET
Packets are multiple variables grouped into a single unit with a defined internal structure. Packets are part of telegrams and messages.
PANTOGRAPH
Device for transmitting power from the overhead catenary to the train.
PARTIAL SUPERVISION MODES
A defined set of ERTMS/ETCS on-board equipment modes used where insufficient track data is available to allow full supervision. The set of partially supervised modes are as follows :  limited supervision  unfitted mode  on sight mode  staff responsible mode  shunting  post trip mode  reversing
implicit-from-entry-label: Passive Shunting mode
Passive Shunting mode
PERMISSIVE SIGNAL
A signal aspect or a signal identification, which enables a main signal to be passed at danger under special conditions, without specific permission from the signalman.
PBD SR
implicit-from-entry-label: Permitted Braking Distance Speed Restriction
Permitted Braking Distance Speed Restriction
implicit-from-entry-label: Permitted speed supervision limit
Permitted speed supervision limit
PERMITTED SPEED
The speed limit at which a train is allowed to proceed without ERTMS/ETCS warning and / or intervention.
POINT
A section of track equipped so that train routes may converge or diverge.
POSSESSION, OF SIGNALLING EQUIPMENT
The disconnection or restriction of use of signalling equipment agreed between maintenance and operations staff to enable work to be carried out on the equipment.
ERTMS/ETCS on-board equipment mode that is entered after a train trip when the train has been brought to a stand and the driver has acknowledged the situation.
POST TRIP MODE
PROCEED ASPECT
Any signal aspect which permits the driver to pass the signal.
PROTECTED WRONG SIDE FAILURE
A wrong side failure where another part of the signalling system provides an acceptable level of protection.
PUBLIC KEY INFRASTRUCTURE (PKI)
Set of hardware, software, people, policies, and procedures needed to create, manage, distribute, use, store, and revoke digital certificates and manage public key encryption with the purpose to facilitate the secure transfer of information for a range of network activities.
PKI
implicit-from-entry-label: Public Key Infrastructure
Public Key Infrastructure
RBC
A centralised safety unit that receives train position information via radio and sends movement authorities via radio to trains.
RADIO BLOCK CENTRE
RADIO HOLE
A known area where it is not possible to establish or maintain a reliable radio connection.
RIU
implicit-from-entry-label: Radio In-fill Unit
Radio In-fill Unit
RADIO INFILL UNIT
A unit which provides a semi-continuous infill function via GSM- R.
implicit-from-entry-label: Railway Undertaking
Railway Undertaking
RBC AREA
Trackside area which is supervised by one RBC.
RBC/RBC BORDER
The border location between two areas supervised by two different RBCs.
RBC/RBC HANDOVER
The process of passing the supervision of a train between two Radio Block Centres.
RBC/RBC TRANSITION
Alternative term to RBC/RBC handover
RECOMMENDED
Not fulfilling the requirement will not have any impact on the technical interoperability of the equipment or of the system but it could be fulfilled to facilitate implementation or to enhance performances.
REDUNDANCY
The provision of one or more additional elements to achieve or maintain availability of a functionality if one or more of those elements “malfunctions”.
REFERENCE LOCATION
A location on the track (e.g. balise group reference location) used as a reference for the information sent from trackside or for the train position
RSM
implicit-from-entry-label: Release Speed Monitoring
Release Speed Monitoring
RELEASE SPEED
A speed value to allow a train to approach theEOA. Needed for intermittent transmission to enable the train to approach a signal that has cleared in order to reach the information point at the signal.
RAM(S)
implicit-from-entry-label: Reliability, Availability, Maintainability, (Safety)
Reliability, Availability, Maintainability, (Safety)
RELIABILITY
The probability that an item can perform a required function under given conditions for a given time interval. (3) Definitions for other reliability related terms are defined in reference 3.
RMP
implicit-from-entry-label: Reverse Movement Protection
Reverse Movement Protection
REVERSE MOVEMENT
A train movement in which the driver is situated in the leading engine but the train is moved in the opposite direction to the train orientation.
ERTMS/ETCS on-board equipment mode that allows the driver to change the direction of movement of the train whilst controlling the train from the same cab.
REVERSING MODE
REVOCATION OF MOVEMENT AUTHORITY
Cancellation of a previously given permission to move a train to a given location.
RIGHT SIDE FAILURE
A failure that does not result in the level of protection normally provided by the signalling system being reduced.
RISK
The combination of the frequency, probability, and the consequence of a specified hazardous event.
RAP
implicit-from-entry-label: Roll Away Protection
Roll Away Protection
ROLL AWAY
An unintended and non-powered movement of the train in a direction, which conflicts with the current position of the direction controller in the active desk.
ROUTE RELEASE
The release of route locking.
ROUTE SUITABILITY DATA
Data transmitted to the ERTMS/ETCS on-board equipment to allow it to check its ability to run on the track as indicated by the movement authority. It includes data related to loading gauge, traction system and axle load category.
ROUTE
The particular section or sections of track, from a starting point to a point of destination, prepared for train operation
SAFE DECELERATION
The deceleration the train is assumed to achieve with a certain confidence level
SAFE STATE
A condition which continues to preserve safety.
SAFETY ACCEPTANCE
The safety acceptance process and the associated terms are given in reference 4.
SIL
implicit-from-entry-label: Safety Integrity Level
Safety Integrity Level
SAFETY LIFE CYCLE
The safety life cycle is defined in reference 4.
SAFETY
Freedom from an unacceptable risk of harm. (3) Definitions for other safety related terms are given in reference 3.
SECTION
A part of the movement authority.
SECURITY
The protection resulting from all measures, also administrative ones, to prevent accidental or malicious modification or disclosure of data; for key management, the protection generally guarantees confidentiality, authenticity and integrity of keys.
SEMI-CONTINUOUS TRANSMISSION
Transmission taking place over a defined distance.
SERVICE BRAKE COMMAND, ETCS
The ERTMS/ETCS service brake command results in the train applying the full service braking effort.
SBD
implicit-from-entry-label: Service Brake Deceleration Curve
Service Brake Deceleration Curve
SBI
implicit-from-entry-label: Service Brake Intervention supervision limit
Service Brake Intervention supervision limit
implicit-from-entry-label: Service Brake or in the context of modes, Stand By mode
Service Brake or in the context of modes, Stand By mode
SERVICE BRAKING
Application of an adjustable brake force in order to control the speed of the train, including stop and temporary immobilisation.
SESSION, COMMUNICATION
The process of initiating and terminating an applicative dialogue between trackside and on-board via radio.
SET SPEED
This is an input received from a function external to ETCS for display to the driver. It represents the speed value to which the train speed is regulated by an external device (e.g. by a cruise control system).
SHALL
Is mandatory.
SHOULD
Is recommended.
ERTMS/ETCS on-board equipment operating mode which allows the train to move in shunting, without available train data.
SHUNTING MODE
SHUNTING MOVEMENT
The movement of trains or vehicles other than normal passage along running lines. When vehicles are moved without train data available.
SHUNTING SIGNAL
A signal provided for shunting movements only. A fixed signal intended for shunting movements. In some cases Shunting signals at danger are valid also for train movements.
SIGNAL LOCATION
The geographical location of a signal.
SIGNALLING SYSTEM
Particular kind of system used on a railway to control and protect the operation of trains.
SIGNAL
A visual display device that conveys instructions or provides advance warning of instructions regarding the driver’s authority to proceed.
SLAVE ENGINE
Any engine that is not the leading Rolling Stock unit of a train or shunting consist. The ERTMS/ETCS on-board equipment of the slave engine runs in one of the modes in which it is not controlling the movement of the train/shunting consist (non leading mode, sleeping mode, passive shunting mode).
ERTMS/ETCS on-board equipment mode that is used for the on-board equipment in slave engines controlled by a leading engine.
SLEEPING MODE
STM
Device allowing the ERTMS/ETCS on-board equipment to be interfaced with the on-board part of an existing National Train Control system. It allows smooth transitions from/to the National System and gives access to some ERTMS/ETCS on-board resources (e.g. DMI).
SPECIFIC TRANSMISSION MODULE
SPEED CONFIDENCE INTERVAL
The interval within which the ERTMS/ETCS on-board assumes the actual train speed with a defined probability.
SPOT TRANSMISSION
Transmission between trackside and on-board that takes place at discrete locations.
ERTMS/ETCS on-board equipment mode that allows a driver to take full responsibility for the movement of a train in an equipped area. The ERTMS/ETCS on-board equipment will impose a speed limit in this mode.
STAFF RESPONSIBLE MODE
STANDBY MODE
ERTMS/ETCS on-board equipment mode that is a default mode when the on-board equipment is powered up or that is entered when shunting or non-leading mode is left or when the active cab is closed.
SoM
implicit-from-entry-label: Start of Mission
Start of Mission
SSP
The description of the fixed speed restrictions of a given line. The speed restrictions can be related to such items as maximum line speed, curves, points, tunnel profiles, bridges.
STATIC SPEED PROFILE
STATION
A place where trains stop, or where loading and unloading occurs, and where assistance may be available. Where there can be points (facing or trailing) that makes it possible for the train to use different routes.
STOP SIGNAL
Any main signal capable of showing a stop danger aspect or indication. Position, from where no movement authority is given to a train. It is not necessarily a fixed signal.
SUB-SYSTEM
A combination of equipment, units, assemblies, etc., which performs an operational function and is a major subdivision of the system.
SvL
implicit-from-entry-label: Supervised Location
Supervised Location
SUPPORTED SYSTEM VERSION
A system version supported by the on-board equipment is one of the system versions the on-board equipment is able to operate. By definition, within one of its supported system version numbers X, the on-board equipment always operates one single system version number Y, which is the highest defined in the release of the ETCS specifications the on-board equipment is compliant with. Important note: if within a system version number X at least two values of Y have been defined, the fact that the on-board always operates/supports the highest value Y does not mean that it is not able to handle trackside information using a lower value of Y.
ERTMS/ETCS on-board equipment mode entered when a fatal failure which could affect safety is found.
SYSTEM FAILURE MODE
SYSTEM LIFE-CYCLE
The system lifecycle and associated terms are defined in reference 3.
implicit-from-entry-label: System National mode
System National mode
SRS
implicit-from-entry-label: System Requirements Specification
System Requirements Specification
SYSTEM VERSION
The system version defines the ERTMS/ETCS mandatory functions that ensure technical interoperability between ERTMS/ETCS on-board equipment and trackside.
SYSTEMATIC FAULT
An inherent fault in the specification, design, construction, installation, operation or maintenance of a system, sub-system or equipment affecting multiple pieces of equipment under identical circumstances.
SYSTEM
A composite of equipment, skills, and techniques capable of performing or supporting an operational role, or both. A complete system includes all equipment, related facilities, material, software, services and personnel required for its operation and support to the degree that it can be considered a self-sufficient unit in its intended operational environment.
TANDEM
Two or more traction units mechanically but not electrically coupled together, used in the same train. Each traction unit requires a separate driver. Only one unit is designated as leading, the other units are therefore classed as non-leading.
TSM
implicit-from-entry-label: Target Speed Monitoring
Target Speed Monitoring
TARGET
Location where the train speed should be below the given target speed
TELEGRAM
A balise telegram contains one header and an identified and coherent set of packets. A balise group message maybe comprised of one or several telegrams.
TSR
A planned speed restriction imposed for temporary conditions such as track maintenance.
TEMPORARY SPEED RESTRICTION
ERTMS/ETCS
implicit-from-entry-label: The ETCS part of ERTMS
The ETCS part of ERTMS
ERTMS/GSM-R
implicit-from-entry-label: The GSM-R part of ERTMS
The GSM-R part of ERTMS
TTI
implicit-from-entry-label: Time to Indication
Time to Indication
TRACK CONDITION
Information transmitted to the ERTMS/ETCS on-board equipment to inform the driver and/or the train of conditions ahead. This information is dedicated to other functions than the speed and distance monitoring.
TRACK DESCRIPTION
Information complementing the Movement Authority and providing as a minimum the, static speed profile and gradient profile. Optionally, it can contain axle load profile, track conditions, route suitability data, areas where shunting is permitted, etc.
TRACK FREE
A route being detected clear of obstacles such that permission may be given for a train to enter that route.
TRACK GEOMETRY
The physical arrangement of the track in terms of curvature, gradient and cant.
TRACK OCCUPIED
An object in a route that prevents that route being offered to a train.
TRACK-TO-TRAIN TRANSMISSION
The transmission of ERTMS/ETCS messages from trackside equipment to the train via balise, loop or radio. Using intermittent transmission (balise or loop or radio infill) the information can only be transmitted to a train passing the transmission unit.
TRACKSIDE EQUIPMENT
The equipment with the aim of exchanging information with the vehicle for safely supervising train circulation. The information exchanged between track and trains can be either continuous or intermittent according to the ERTMS/ETCS level of application and to the nature of the information itself.
TRK
implicit-from-entry-label: Trackside
Trackside
TCO
implicit-from-entry-label: Traction Cut Off
Traction Cut Off
TRACTION UNIT
A powered vehicle able to move itself and other vehicles to which it may be coupled.
TRAIN DATA
Defined set of data which gives information about the train. Data that characterises a train and which is acquired by ERTMS/ETCS in order to perform a mission.
TRAIN DETECTION
The proof of the presence or absence of trains on a defined section of line.
TRAIN INTEGRITY
The level of belief in the train being complete and not having left coaches or wagons behind.
TIU
The unit, inside the ERTMS/ETCS on-board equipment, that provides the interface between the ERTMS/ETCS on-board equipment and the train.
TRAIN INTERFACE UNIT
implicit-from-entry-label: Train Interface
Train Interface
TRAIN MOVEMENT
When vehicles are moved with train data available, as a rule from station to station, and as a rule under the authority of proceed aspects from main signals, or similar procedures.
TRAIN ORIENTATION
If there is an active cab, this one defines the orientation of the train, i.e. the side of the active cab is considered as the front of the train. If no cab is active, the train orientation is as when a cab was last active.
TRAIN POSITION CONFIDENCE INTERVAL
The distance interval within which the ERTMS/ETCS on-board assumes the actual train position is, with a defined probability. It comprises the odometer over-reading and under-reading amounts, plus twice the location accuracy of the reference balise group.
TRAIN RUNNING NUMBER
A number under which the train is operated.
TRAIN TRIP
Initiated when a train passes an EOA/LOA, excluding any occasion when a suppress facility is used, and causes an immediate application of the emergency brake.
TRAIN-TO-TRACK TRANSMISSION
The transmission of ERTMS/ETCS messages from the train to trackside equipment via radio.
TRAIN
One or more railway vehicles hauled by one or more traction units, or one traction unit travelling alone, running under a given operational number from an initial fixed point to a terminal fixed point.
TRANSITIONS
The controlled changes between operating modes and / or levels
TCP
implicit-from-entry-label: Transmission Control Protocol
Transmission Control Protocol
TRANSPONDER
See Balise and Eurobalise
KTRANS
implicit-from-entry-label: Transport Key
Transport Key
ERTMS/ETCSERTMS/ETCS on-board equipment mode (e.g. entered when passing an EOA), resulting in an application of the emergency brake that can only be revoked at standstill and with additional precautions.
TRIP MODE
UNCOMMISSIONED AREA
Piece of track where ERTMS/ETCS is being installed but has not yet been commissioned and shall thus not be taken into account.
UNDER-READING AMOUNT
The distance the train may have travelled further than the estimated position. The distance is estimated by the ERTMS/ETCS-on-board equipment taking into account the odometer inaccuracy plus the error for the detection of a balise location, as defined in the Eurobalise specifications.
UNFITTED AREA
See NON-EQUIPPED LINE
ERTMS/ETCS on-board equipment mode allowing a fitted train to run in an unfitted area.
UNFITTED MODE
UNISIG
implicit-from-entry-label: UNIFE ETCS Working group
UNIFE ETCS Working group
UIC
implicit-from-entry-label: Union Internationale des Chemins de Fer
Union Internationale des Chemins de Fer
UTC
implicit-from-entry-label: Universal Time Co-ordinated
Universal Time Co-ordinated
UNPROTECTED WRONG SIDE FAILURE
A wrong side failure where no other part of the signalling system provides protection.
VALIDATION
Confirmation by examination and provision of objective evidence that the particular requirements for a specific intended use have been fulfilled.
VALIDATOR
The person or agent appointed to carry out validation.
VARIABLE
A set of bits which are given a unique identity and meaning.
V&V
implicit-from-entry-label: Verification and Validation
Verification and Validation
VERIFICATION
Confirmation, by examination and provision of objective evidence, that the specified requirements for the lifecycle phase have been fulfilled.
VERIFIER
The person or agent appointed to carry out verification.
VBC
A specific marker in balise telegrams, that allows substituting the physical cover plates in lines under construction.
VIRTUAL BALISE COVER
VITAL
A description applied to equipment whose correct operation is essential to the integrity of the signalling system. Most vital equipment is designed to fail-safe principles - a wrong side failure of vital equipment could directly endanger rail traffic.
implicit-from-entry-label: Warning supervision limit
Warning supervision limit
WARNING
Audible and/or visual indication to alert the driver to a condition which requires a positive action by the driver.
WHEELSLIDE
When a braked wheel loses adhesion with the rails and under rotates.
WHEELSLIP
When a traction-driven wheel loses adhesion with the rails and over rotates
WSF
An equipment failure tending to cause danger to rail traffic.
WRONG SIDE FAILURE
Railway Infrastructure