14.3 Inter-RAT measurements
25.3313GPPProtocol specificationRadio Resource Control (RRC)Release 17TS
14.3.0a Inter-RAT measurement quantities
A measurement quantity is used by the UE to evaluate whether an inter-RAT measurement event has occurred or not.
The measurement quantity for UTRAN is used to compute the frequency quality estimate for the active set, as described in the next subclause, and can be:
1 Downlink Ec/No.
2 Downlink received signal code power (RSCP) after despreading.
The measurement quantity for GSM can be:
1 GSM Carrier RSSI
The measurement quantity for E-UTRA can be:
1 E-UTRA RSRP
2 E-UTRA RSRQ
A description of those values can be found in [7] and [8].
14.3.0b Frequency quality estimate of the UTRAN frequency
The estimated quality of the active set in UTRAN in event 3a is defined as:
The variables in the formula are defined as follows:
QUTRAN is the estimated quality of the active set on the currently used UTRAN frequency.
MUTRAN is the estimated quality of the active set on currently used UTRAN frequency expressed in another unit.
Mi is the measurement result of cell i in the active set, according to what is indicated in the IE "Measurement quantity for UTRAN quality estimate".
NA is the number of cells in the active set.
MBest is the measurement result of the cell in the active set with the highest measurement result.
W is a parameter sent from UTRAN to UE.
If the measurement result is CPICH-Ec/No MUTRAN, Mi and MBest are expressed as ratios.
If the measurement result is CPICH-RSCP or PCCPCH-RSCP, MUTRAN, Mi and MBest are expressed in mW.
14.3.0c Inter-RAT reporting quantities
The quantities that the UE shall report to UTRAN when the event is triggered for an inter-RAT measurement are given by the IE "Inter-RAT reporting quantity" stored for that measurement, and can be the following:
In the case the other RAT is GSM:
1 GSM carrier RSSI
In the case the other RAT is E-UTRA:
1 Measurement Quantity: In case the measurement quantity is RSRP then only RSRP is reported; in case the measurement quantity is RSRQ then only RSRQ is reported.
2 Both: both RSRP and RSRQ are reported.
A description of those values can be found in [7], [8] and [74].
14.3.1 Inter-RAT reporting events
Within the measurement reporting criteria field in the MEASUREMENT CONTROL message the UTRAN notifies the UE which events should trigger the UE to send a MEASUREMENT REPORT message. The listed events are the toolbox from which the UTRAN can choose the reporting events that are needed for the implemented handover evaluation function, or other radio network functions.
All events are measured with respect to one of the measurement quantities given in subclause 14.3.0a, and of the frequency quality estimate given in subclause 14.3.0b. For UTRAN the measurement quantities are measured on the monitored primary common pilot channels (CPICH) in FDD mode and the monitored primary common control channels (PCCPCH) in TDD mode of the cell defined in the measurement object. For other RATs the measurement quantities are system-specific. A "used UTRAN frequency" is a frequency that the UE have been ordered to measure upon and is also currently used for the connection to UTRAN. "Other system" is e.g. GSM or E-UTRA.
In the text below describing the events:
– "The BCCH ARFCN and BSIC combinations considered in that inter-RAT measurement" shall be understood as the BCCH ARFCN and BSIC combinations of the inter-RAT cells pointed at in the IE "Cells for measurement" if it has been received for that inter-RAT measurement, or otherwise of the cells included in the "inter-RAT cell info" part of the variable CELL_INFO LIST.
– "The BCCH ARFCNs considered in that inter-RAT measurement" shall be understood as the BCCH ARFCNs of the inter-RAT cells pointed at in the IE "Cells for measurement" if it has been received for that inter-RAT measurement, or otherwise of the cells included in the "inter-RAT cell info" part of the variable CELL_INFO LIST.
– "The E-UTRA frequencies considered in that inter-RAT measurement" shall be understood as the E-UTRA frequencies whose EARFCNs is included in the variable EUTRA_FREQUENCY_INFO LIST.
When one inter-RAT measurement identity corresponds to multiple inter-RAT events with identical event identities, the UE behaviour is not specified.
14.3.1.1 Event 3a: The estimated quality of the currently used UTRAN frequency is below a certain threshold and the estimated quality of the other system is above a certain threshold.
When an inter-RAT measurement configuring event 3a is set up, the UE shall:
1> create a variable TRIGGERED_3A_EVENT related to that measurement, which shall initially be empty;
1> delete this variable when the measurement is released.
When event 3a is configured in the UE within a measurement, the UE shall:
1> if the other RAT is GSM, and if IE "BSIC verification required" is set to "required":
2> if equations 1 and 2 below have both been fulfilled for a time period indicated by "Time to trigger" from the same instant, respectively for the used UTRAN frequency and for one or several GSM cells that match any of the BCCH ARFCN and BSIC combinations considered in that inter-RAT measurement:
3> if the Inter-RAT cell id of any of those GSM cells is not stored in the variable TRIGGERED_3A_EVENT:
4> store the Inter-RAT cell ids of the GSM cells that triggered the event and that were not previously stored in the variable TRIGGERED_3A_EVENT into that variable.
4> send a measurement report with IEs set as below:
5> in "inter-RAT measurement event result": "inter-RAT event identity" to "3a", "CHOICE BSIC" to "verified BSIC" and "Inter-RAT cell id" to the GSM cells that triggered the event (best one first), taking into account the cell individual offset of the GSM cells;
5> "measured results" and possible "additional measured results" according to subclause 8.6.7.5 and 8.4.2, respectively, not taking into account the cell individual offset.
2> if equation 4 is fulfilled for a GSM cell whose inter-RAT cell id is stored in the variable TRIGGERED_3A_EVENT:
3> remove the inter-RAT cell id of that GSM cell from the variable TRIGGERED_3A_EVENT.
2> if equation 3 is fulfilled for the used frequency in UTRAN:
3> clear the variable TRIGGERED_3A_EVENT.
1> if the other RAT is GSM, and if IE "BSIC verification required" is set to "not required":
2> if equations 1 and 2 below have been fulfilled for a time period indicated by "Time to trigger" from the same instant, respectively for the used UTRAN frequency and for one or several BCCH ARFCNs considered in that inter-RAT measurement:
3> if any of those BCCH ARFCNs is not stored into the variable TRIGGERED_3A_EVENT:
4> store the BCCH ARFCNs that triggered the event and that were not previously stored in the variable TRIGGERED_3A_EVENT into that variable;
4> send a measurement report with IEs set as below:
5> in "inter-RAT measurement event result": "inter-RAT event identity" to "3a", "CHOICE BSIC" to "non verified BSIC" and "BCCH ARFCN" to BCCH ARFCNs that triggered the event (best one first), taking into account the cell individual offset of the GSM cells;
5> "measured results" and possible "additional measured results" according to subclause 8.6.7.5 and 8.4.2, respectively, not taking into account the cell individual offset.
2> if equation 4 is fulfilled for a BCCH ARFCN that is stored in the variable TRIGGERED_3A_EVENT:
3> remove that BCCH ARFCN from the variable TRIGGERED_3A_EVENT.
2> if equation 3 is fulfilled for the used frequency in UTRAN:
3> clear the variable TRIGGERED_3A_EVENT.
1> if the other RAT is E-UTRA:
2> if equations 1 and 2 below have been fulfilled for a time period indicated by "Time to trigger" from the same instant, respectively for the used UTRAN frequency and for one or several E-UTRA cells on any of the frequencies considered in that inter-RAT measurement and that are not included in the exclude-list:
3> if any of those E-UTRA cells are not stored into the variable TRIGGERED_3A_EVENT:
4> store the E-UTRA cells that triggered the event and that were not previously stored in the variable TRIGGERED_3A_EVENT into that variable;
4> send a measurement report with IEs set as below:
5> in "E-UTRA event results": "inter-RAT event identity" to "3a", and "E-UTRA carrier frequency" and "Physical cell identity" to the EARFCN and physical cell identity of the cells that triggered the event (best one first);
5> "E-UTRA measured results" according to subclause 8.6.7.5.
2> if equation 4 is fulfilled for a cell that is stored in the variable TRIGGERED_3A_EVENT:
3> remove that cell from the variable TRIGGERED_3A_EVENT.
2> if equation 3 is fulfilled for the used frequency in UTRAN:
3> clear the variable TRIGGERED_3A_EVENT.
Triggering conditions:
Equation 1:
The variables in the formula are defined as follows:
QUsed is the quality estimate of the used UTRAN frequency.
TUsed is the absolute threshold that applies for the used frequency in that measurement.
H3a is the hysteresis parameter for event 3a.
Equation 2:
The variables in the formula are defined as follows:
MOther RAT is the measurement quantity for the cell of the other system.
CIOOther RAT is the cell individual offset for the cell of the other system.
TOther RAT is the absolute threshold that applies for the other system in that measurement.
H3a is the hysteresis parameter for event 3a.
Leaving triggered state conditions:
Equation 3:
The variables in the formula are defined as follows:
QUsed is the quality estimate of the used UTRAN frequency.
TUsed is the absolute threshold that applies for the used frequency in that measurement.
H3a is the hysteresis parameter for event 3a.
Equation 4:
The variables in the formula are defined as follows:
MOther RAT is the measurement quantity for the cell of the other system. MOther RAT is expressed in dBm.
CIOOther RAT is the cell individual offset for the cell of the other system.
TOther RAT is the absolute threshold that applies for the other system in that measurement.
H3a is the hysteresis parameter for event 3a.
14.3.1.2 Event 3b: The estimated quality of other system is below a certain threshold
When an inter-RAT measurement configuring event 3b is set up, the UE shall:
1> create a variable TRIGGERED_3B_EVENT related to that measurement, which shall initially be empty;
1> delete this variable when the measurement is released.
When event 3b is configured in the UE within a measurement, the UE shall:
1> if the other RAT is GSM, and if IE "BSIC verification required" is set to "required":
2> if equation 1 below has been fulfilled for a time period indicated by "time to trigger" for one or several GSM cells that match any of the BCCH ARFCN and BSIC combinations considered in that inter-RAT measurement:
3> if the inter-RAT cell id of any of those GSM cell is not stored in the variable TRIGGERED_3B_EVENT:
4> store the inter-RAT cell ids of the GSM cells that triggered the event and that were not previously stored in the variable TRIGGERED_3B_EVENT into that variable;
4> send a measurement report with IEs set as below:
5> set in "inter-RAT measurement event result": "inter-RAT event identity" to "3b", "CHOICE BSIC" to "verified BSIC" and "Inter-RAT cell id" to the GSM cells that triggered the event (worst one first), taking into account the cell individual offset of the GSM cells;
5> set the IE "measured results" and the IE "additional measured results" according to subclause 8.6.7.5 and 8.4.2, respectively, not taking into account the cell individual offset.
2> if equation 2 below is fulfilled for a GSM cell whose inter-RAT cell id is stored in the variable TRIGGERED_3B_EVENT:
3> remove the inter-RAT cell id of that GSM cell from the variable TRIGGERED_3B_EVENT.
1> if the other RAT is GSM, and if IE "BSIC verification required" is set to "not required":
2> if equation 1 below has been fulfilled for a time period indicated by "time to trigger" for one or several of the BCCH ARFCNs considered in that inter-RAT measurement:
3> if any of those BCCH ARFCN is not stored into the variable TRIGGERED_3B_EVENT:
4> store the BCCH ARFCNs that triggered the event and that were not previously stored in the variable TRIGGERED_3B_EVENT into that variable;
4> send a measurement report with IEs set as below:
5> set in "inter-RAT measurement event result": "inter-RAT event identity" to "3b", "CHOICE BSIC" to "non verified BSIC" and "BCCH ARFCN" to BCCH ARFCNs that triggered the event (worst one first), taking into account the cell individual offset of the GSM cells;
5> set the IE "measured results" and the IE "additional measured results" according to subclause 8.6.7.5 and 8.4.2, respectively, not taking into account the cell individual offset.
2> if equation 2 below is fulfilled for a BCCH ARFCN that is stored in the variable TRIGGERED_3B_EVENT:
3> remove that BCCH ARFCN from the variable TRIGGERED_3B_EVENT.
1> if the other RAT is E-UTRA:
2> if equation 1 below has been fulfilled for a time period indicated by "time to trigger" for one or several of the E-UTRA cells on any of the frequencies considered in that inter-RAT measurement and that are not included in the exclude-list:
3> if any of those E-UTRA cells is not stored into the variable TRIGGERED_3B_EVENT:
4> store the E-UTRA cells that triggered the event and that were not previously stored in the variable TRIGGERED_3B_EVENT into that variable;
4> send a measurement report with IEs set as below:
5> set in "E-UTRA event results": "inter-RAT event identity" to "3b", and "E-UTRA carrier frequency" and "Physical cell identity" to the EARFCN and physical cell identity of the cells that triggered the event (worst one first);
5> set the IE "E-UTRA measured results" according to subclause 8.6.7.5.
2> if equation 2 below is fulfilled for a cell that is stored in the variable TRIGGERED_3B_EVENT:
3> remove that cell from the variable TRIGGERED_3B_EVENT.
Triggering condition:
Equation 1:
The variables in the formula are defined as follows:
MOther RAT is the measurement quantity for the cell of the other system.
CIOOther RAT is the cell individual offset for the cell of the other system.
TOther RAT is the absolute threshold that applies for the other system in that measurement.
H3b is the hysteresis parameter for event 3b.
Leaving triggered state condition:
Equation 2:
The variables in the formula are defined as follows:
MOther RAT is the measurement quantity for the cell of the other system. MOther RAT is expressed in dBm.
CIOOther RAT is the cell individual offset for the cell of the other system.
TOther RAT is the absolute threshold that applies for the other system in that measurement.
H3b is the hysteresis parameter for event 3b.
14.3.1.3 Event 3c: The estimated quality of other system is above a certain threshold
When an inter-RAT measurement configuring event 3c is set up, the UE shall:
1> create a variable TRIGGERED_3C_EVENT related to that measurement, which shall initially be empty;
1> delete this variable when the measurement is released.
When event 3c is configured in the UE within a measurement, the UE shall:
1> if the other RAT is GSM, and if IE "BSIC verification required" is set to "required":
2> if equation 1 below has been fulfilled for a time period indicated by "time to trigger" for one or several GSM cells that match any of the BCCH ARFCN and BSIC combinations considered in that inter-RAT measurement:
3> if the inter-RAT cell id of any of those GSM cell is not stored in the variable TRIGGERED_3C_EVENT:
4> store the Inter-RAT cell ids of the GSM cells that triggered the event and that were not previously stored in the variable TRIGGERED_3C_EVENT into that variable;
4> send a measurement report with IEs set as below:
5> set in "inter-RAT measurement event result": "inter-RAT event identity" to "3c", "CHOICE BSIC" to "verified BSIC" and "Inter-RAT cell id" to the GSM cells that triggered the event (best one first), taking into account the cell individual offset of the GSM cells;
5> set the IE "measured results" and the IE "additional measured results" according to subclause 8.6.7.5 and 8.4.2, respectively, not taking into account the cell individual offset.
2> if equation 2 below is fulfilled for a GSM cell whose inter-RAT cell id is stored in the variable TRIGGERED_3C_EVENT:
3> remove the inter-RAT cell id of that GSM cell from the variable TRIGGERED_3C_EVENT.
1> if the other RAT is GSM, and if IE "BSIC verification required" is set to "not required":
2> if equation 1 below has been fulfilled for a time period indicated by "time to trigger" for one or several of the BCCH ARFCNs considered in that inter-RAT measurement:
3> if any of those BCCH ARFCN is not stored into the variable TRIGGERED_3C_EVENT:
4> store the BCCH ARFCNs that triggered the event and that were not previously stored in the variable TRIGGERED_3C_EVENT into that variable;
4> send a measurement report with IEs set as below:
5> set in "inter-RAT measurement event result": "inter-RAT event identity" to "3c", "CHOICE BSIC" to "non verified BSIC" and "BCCH ARFCN" to BCCH ARFCNs that triggered the event (best one first), taking into account the cell individual offset of the GSM cells;
5> set the IE "measured results" and the IE "additional measured results" according to subclause 8.6.7.5 and 8.4.2, respectively, not taking into account the cell individual offset.
2> if equation 2 is fulfilled for a BCCH ARFCN that is stored in the variable TRIGGERED_3C_EVENT:
3> remove that BCCH ARFCN from the variable TRIGGERED_3C_EVENT.
1> if the other RAT is E-UTRA:
2> if equation 1 below has been fulfilled for a time period indicated by "time to trigger" for one or several E-UTRA cells on any of the frequencies considered in that inter-RAT measurement and that are not included in the exclude-list:
3> if any of those E-UTRA cells is not stored into the variable TRIGGERED_3C_EVENT:
4> store the E-UTRA cells that triggered the event and that were not previously stored in the variable TRIGGERED_3C_EVENT into that variable;
4> send a measurement report with IEs set as below:
5> set in "E-UTRA event results": "inter-RAT event identity" to "3c", and "E-UTRA carrier frequency" and "Physical cell identity" to the EARFCN and physical cell identity of the cells that triggered the event (best one first);
5> set the IE "E-UTRA measured results" according to subclause 8.6.7.5.
2> if equation 2 is fulfilled for a cell that is stored in the variable TRIGGERED_3C_EVENT:
3> remove that cell from the variable TRIGGERED_3C_EVENT.
Triggering condition:
Equation 1:
The variables in the formula are defined as follows:
MOther RAT is the measurement quantity for the cell of the other system. MOther RAT is expressed in dBm.
CIOOther RAT is the cell individual offset for the cell of the other system.
TOther RAT is the absolute threshold that applies for the other system in that measurement.
H3c is the hysteresis parameter for event 3c.
Leaving triggered state condition:
Equation 2:
The variables in the formula are defined as follows:
MOther RAT is the measurement quantity for the cell of the other system. MOther RAT is expressed in dBm.
CIOOther RAT is the cell individual offset for the cell of the other system.
TOther RAT is the absolute threshold that applies for the other system in that measurement.
H3c is the hysteresis parameter for event 3c.
14.3.1.4 Event 3d: Change of best cell in other system
When an inter-RAT measurement configuring event 3d is set up, the UE shall:
1> create a variable BEST_CELL_3D_EVENT related to that measurement;
1> delete this variable when the measurement is released.
When event 3d is configured in the UE within a measurement, the UE shall:
1> if the other RAT is GSM, and if IE "BSIC verification required" is set to "required":
2> when the measurement is initiated or resumed:
3> store in the variable BEST_CELL_3D_EVENT the Inter-RAT cell id of the GSM cell that has the best measured quantity among the GSM cells that match any of the BCCH ARFCN and BSIC combinations considered in that inter-RAT measurement, not taking into account the cell individual offset of the GSM cells;
3> send a measurement report with IE set as below:
4> set in "inter-RAT measurement event result": "inter-RAT event identity" to "3d", "CHOICE BSIC" to "verified BSIC" and "Inter-RAT cell id" to the GSM cell that is stored in the variable BEST_CELL_3D_EVENT;
4> set the IE "measured results" and the IE "additional measured results" according to subclause 8.6.7.5 and 8.4.2, respectively, not taking into account the cell individual offset.
2> if equation 1 has been fulfilled for a time period indicated by "time to trigger" for a GSM cell that is different from the one stored in BEST_CELL_3D_EVENT and that matches any of the BCCH ARFCN and BSIC combinations considered in that inter-RAT measurement:
3> store the Inter-RAT cell id of that GSM cell in the variable BEST_CELL_3D_EVENT;
3> send a measurement report with IEs set as below:
4> set in "inter-RAT measurement event result": "inter-RAT event identity" to "3d", "CHOICE BSIC" to "verified BSIC" and "Inter-RAT cell id" to the GSM cell is now stored in BEST_CELL_3D_EVENT;
4> set the IE "measured results" and the IE "additional measured results" according to subclause 8.6.7.5 and 8.4.2, respectively, not taking into account the cell individual offset.
1> if the other RAT is GSM, and if IE "BSIC verification required" is set to "not required":
2> when the measurement is initiated or resumed:
3> store in the variable BEST_CELL_3D_EVENT the BCCH ARFCN of the GSM cell that has the best measured quantity among the BCCH ARFCNs considered in that inter-RAT measurement;
3> send a measurement report with IE set as below:
4> set in "inter-RAT measurement event result": "inter-RAT event identity" to "3d", "CHOICE BSIC" to "non verified BSIC" and "BCCH ARFCN" to the BCH ARFCN that is stored in the variable BEST_CELL_3D_EVENT;
4> set the IE "measured results" and the IE "additional measured results" according to subclause 8.6.7.5 and 8.4.2, respectively, not taking into account the cell individual offset.
2> if equation 1 below has been fulfilled for a time period indicated by "time to trigger" for one of the BCCH ARFCNs considered in that inter-RAT measurement and different from the one stored in BEST_CELL_3D_EVENT:
3> store the BCCH ARFCN of that GSM cell in the variable BEST_CELL_3D_EVENT;
3> send a measurement report with IEs set as below:
4> set in "inter-RAT measurement event result": "inter-RAT event identity" to "3d", "CHOICE BSIC" to "non verified BSIC" and "BCCH ARFCN" to the BCCH ARFCN that is now stored in the variable BEST_CELL_3D_EVENT;
4> set the IE "measured results" and the IE "additional measured results" according to subclause 8.4.2, not taking into account the cell individual offset.
1> if the other RAT is E-UTRA:
2> when the measurement is initiated or resumed:
3> store in the variable BEST_CELL_3D_EVENT the EARFCN and Physical Cell Identity of the E-UTRA cell that has the best measured quantity among the EARFCNs considered in that inter-RAT measurement;
3> send a measurement report with IE set as below:
4> set in "E-UTRA measurement results": "inter-RAT event identity" to "3d", and "E-UTRA Carrier Frequency" and "Physical Cell Identity" to the EARFCN and the Physical Cell Identity that are stored in the variable BEST_CELL_3D_EVENT;
4> set the IE "E-UTRA measured results" according to subclause 8.6.7.5.
2> if equation 1 below has been fulfilled for a time period indicated by "time to trigger" for a cell on one of the EARFCNs considered in that inter-RAT measurement and different from the cell stored in BEST_CELL_3D_EVENT:
3> store the EARFCN and Physical Cell Identity of that E-UTRA cell in the variable BEST_CELL_3D_EVENT;
3> send a measurement report with IEs set as below:
4> set in "E-UTRA event results": "inter-RAT event identity" to "3d", and "E-UTRA carrier frequency" and "Physical Cell Identity" to the EARFCN and the Physical Cell Identity that are now stored in the variable BEST_CELL_3D_EVENT;
4> set the IE "E-UTRA measured results" according to subclause 8.6.7.5.
Equation 1:
The variables in the formula are defined as follows:
MNew is the measurement quantity for a cell of the other system that is not stored in the variable BEST_CELL_3D_EVENT.
MBest is the measurement quantity for a cell of the other system that is stored in the variable BEST_CELL_3D_EVENT.
H3d is the hysteresis parameter for event 3d.
14.3.2 GSM measurements in compressed mode
14.3.2.1 GSM RSSI measurements
The UE shall perform GSM RSSI measurements in the gaps of compressed mode pattern sequence specified for GSM RSSI measurement purpose.
14.3.2.2 Initial BSIC identification
The UE shall perform Initial BSIC identification in compressed mode pattern sequence specified for Initial BSIC identification measurement purpose.
The parameter "N identify abort" in the IE "DPCH compressed mode info" indicates the maximum number of patterns that the UE shall use to attempt to decode the unknown BSIC of the GSM cell in the initial BSIC identification procedure.
The BSIC identification procedure is defined in detail in [19].
14.3.2.3 BSIC re-confirmation
The UE shall perform BSIC re-confirmation in compressed mode pattern sequence specified for BSIC re-confirmation measurement purpose.
The parameter "T reconfirm abort" in the IE "DPCH compressed mode info" indicates the maximum time allowed for the re-confirmation of the BSIC of one GSM cell in the BSIC re-confirmation procedure.
The BSIC re-confirmation procedure is defined in detail in [19].
14.3.3 E-UTRA measurements in compressed mode
14.3.3.1 E-UTRA RSRP measurements
The UE shall perform E-UTRA RSRP measurements in the gaps of compressed mode pattern sequence specified for E-UTRA measurement purpose.
14.3.3.2 E-UTRA RSRQ measurements
The UE shall perform E-UTRA RSRQ measurements in the gaps of compressed mode pattern sequence specified for E-UTRA measurement purpose.