++ "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"
-- "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"
++ "The active cab is the cab associated with an ERTMS/ETCS on-board equipment, from which the traction is controlled"
-- "The active cab is the cab associated with an ERTMS/ETCS on- board equipment, from which the traction is controlled"
++ "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."
-- "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."
++ "The conditions under which the system is called to operate, including: • environmental conditions; • operating conditions; • maintenance conditions."
-- "The conditions under which the system is called to operate, including:  environmental conditions;  operating conditions;  maintenance conditions."
++ "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."
-- "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."
++ "Information transmitted by a balise group intended to mark the beginning of a track area where loop messages can be received. In bidirectional applications, it is possible to have an EOLM at both sides of a loop."
-- "The balise group intended to define where a “loop” begins or ends."
++ "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."
-- "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."
++ "Line equipped with ERTMS/ ETCS in application level 1 or 2"
-- "Line equipped with ERTMS/ ETCS in application level 1, 2 or 3"
++ "Signalling and operation management system encompassing ETCS for the Control Command, ATO for the Automatic Train Operation and FRMCS and/or GSM-R for voice and data communication. FRMCS and/or GSM-R are/is used as radio bearer for ETCS and ATO."
-- "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."
++ "Specific location on the track where information can be transmitted from ERTMS/ETCS trackside to ERTMS/ETCS on-board equipment (see also SPOT TRANSMISSION)"
-- "Specific location on the track where information can be transmitted from ERTMS/ETCS trackside to ERTMS/ETCS on- board equipment (see also SPOT TRANSMISSION)"
++ "A term that encompasses “SPOT TRANSMISSION” and “SEMI-CONTINUOUS TRANSMISSION”."
-- "A term that encompasses “SPOT TRANSMISSION” and “SEMI- CONTINUOUS TRANSMISSION”."
++ "Interoperability means the ability to allow the safe and uninterrupted movement of trains that accomplish the specified levels of performance. (1)"
-- "Interoperabilitymeanstheabilitytoallowthesafeand uninterrupted movement of trains that accomplish the specified levels of performance. (1)"
++ "When the ERTMS/ETCS on-board equipment is disconnected from the vehicle braking system. Isolation is indicated to the driver."
-- "When the ERTMS/ETCS on-board equipment is disconnected from the vehicle braking system. Isolation is indicated to the driver."
++ "The LRBG is the last balise group marked as linked encountered by the train, whose message is accepted by the ERTMS/ETCS on-board. It is used as a common location reference between the ERTMS/ETCS on-board and trackside equipment."
-- "The LRBG is used as a common location reference between the ERTMS/ETCS on-board and trackside equipments in levels 2 & 3"
++ "A level of ERTMS/ETCS that uses radio to pass movement authorities to the train. Train reported position and integrity may be used to determine the parts of the track that are occupied by the train."
-- "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."
++ "Track mounted device for the transmission of data between track-to-train within a defined area."
-- "Track mounted device for the transmission of data between track- to-train within a defined area."
++ "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)."
-- "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)."
++ "The maximum safe front end position differs from the estimated position by the Under-reading Amount in the distance measured from the LRBG/ORBG plus the Location Accuracy of the LRBG/ORBG plus, when relevant, the difference between the max safe consist length and nominal consist length in front of/in rear of the engine, depending on whether the train orientation is the same as/opposite to the active cab respectively"
-- "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"
++ "The minimum safe front end position differs from the estimated position by the Over-reading Amount in the distance measured from the LRBG/ORBG plus the Location Accuracy of the LRBG/ORBG plus, when relevant, the difference between the min safe consist length and nominal consist length in front of/in rear of the engine, depending on whether the train orientation is the same as/opposite to the active cab respectively"
-- "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"
++ "Any train movement started under the supervision of an ERTMS/ETCS on-board equipment in one the following modes: FS, LS, SR, OS, SM, NL, UN, or SN. The ETCS mission is ended when any of the following modes is entered: SB, SH, NP"
-- "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"
++ "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."
-- "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."
++ "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."
-- "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."
++ "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"
-- "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"
++ "A unit which provides a semi-continuous infill function via GSM-R."
-- "A unit which provides a semi-continuous infill function via GSM- R."
++ "A speed value to allow a train to approach the EOA. 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."
-- "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."
++ "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."
-- "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."
++ "Freedom from an unacceptable risk of harm. (3) Definitions for other safety related terms are given in reference 3."
-- "Freedom from an unacceptable risk of harm. (3) Definitions for other safety related terms are given in reference 3."
++ "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)."
-- "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)."
++ "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."
-- "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."
++ "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."
-- "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."
++ "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."
-- "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."
++ "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."
-- "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."
++ "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."
-- "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."