4 Idle Mode Tasks
25.1333GPPRelease 17Requirements for support of radio resource management (FDD)TS
4.1 Cell Selection
4.1.1 Introduction
After a UE has switched on and a PLMN has been selected, the Cell selection process takes place, as described in TS25.304. This process allows the UE to select a suitable cell where to camp on in order to access available services. In this process the UE can use stored information (Stored information cell selection) or not (Initial cell selection).
4.2 Cell Re-selection
4.2.1 Introduction
The cell reselection procedure allows the UE to select a more suitable cell and camp on it.
When the UE is in either Camped Normally state or Camped on Any Cell state on a FDD cell, the UE shall attempt to detect, synchronise, and monitor intra-frequency, inter-frequency and inter-RAT cells indicated in the measurement control system information of the serving cell. UE measurement activity is also controlled by measurement rules defined in TS25.304, allowing the UE to limit its measurement activity if certain conditions are fulfilled.
4.2.2 Requirements
In the following sections, Thigher_priority_search is defined as (60 * Nlayers) seconds when eDRX_IDLE is not configured, and as MAX(one eDRX_IDLE cycle, 60 * Nlayers) when eDRX_IDLE is configured, where Nlayers is the total number of configured higher priority E-UTRA, UTRA FDD and UTRA TDD carrier frequencies and is additionally increased by one if one or more groups of GSM frequencies is configured as a higher priority.
For a UE which supports increased carrier monitoring UTRA or increased carrier monitoring E-UTRA, the reselection performance for different carriers may be configured by higher layers to be either normal or reduced. The following definitions are used in the performance requirements:
Ncarrier-1: Total number of FDD interfrequency carriers in the interfrequecny neighbour cell info list
Nnorm,inter = (Ncarrier-1- Nreduced,inter): Number of FDD interfrequency carriers to be monitored with normal performance
Nreduced,inter: Number of FDD interfrequency carriers to be monitored with reduced performance
Kcarrier: Total number of configured E-UTRA carriers in the neighbour cell list
Knorm,E-UTRA =( Kcarrier – Kreduced,E-UTRA): Number of E-UTRA carriers to be monitored with normal performance
Knorm,E-UTRA,FDD : number of configured FDD E-UTRA carriers in the neighbour cell list to be monitored with normal performance
Knorm,E-UTRA,TDD : number of configured TDD E-UTRA carriers in the neighbour cell list to be monitored with normal performance
Kreduced,E-UTRA: Number of E-UTRA carriers to be monitored with reduced performance
The minimum performance requirements for a UE which supports Increased UE carrier monitoring UTRA [16, 31] are calculated as defined in sections 4.2.2.3 provided that Nnorm,inter ≤2 for FDD and Nnorm,inter ≤3 for TDD and the minimum performance requirements for a UE which supports Increased UE carrier monitoring E-UTRA [16, 31] are calculated as defined in sections 4.2.2.5a provided that Knorm,E-UTRA≤4 for a UE capable of of either FDD E-UTRA carrier monitoring or TDD E-UTRA carrier monitoring or Knorm,E-UTRA≤8 for a UE capable of both FDD and TDD E-UTRA carrier monitoring provided Knorm,E-UTRA,FDD ≤4 and Knorm,E-UTRA,TDD ≤4. In case the limits for the number of normal performance carriers is exceeded, considering the broadcast neighbour cell list and the bands supported by the UE, the UE which supports Increased UE carrier monitoring UTRA shall measure the first-listed 2 UTRA FDD carriers in the Inter-frequency cell info list with normal performance and the UE capable of either FDD or TDD carrier monitoring which supports Increased UE carrier monitoring E-UTRA shall measure the first-listed 4 E-UTRA carriers, and a UE capable of both FDD/TDD carrier monitoring the first-listed 4 FDD E-UTRA carriers and first-listed 4 TDD E-UTRA carriers in the Inter-RAT cell info list, with normal performance. Additionally, reduced performance requirements shall be met for carriers for which the Reduced measurement performance IE is indicated, up to the UE measurement capability in section 4.2.2.8a.
The minimum performance requirements for a UE which does not support Increased UE carrier monitoring UTRA [16,31] are calculated assuming all UTRA carriers required to be monitored for such UE, are having normal performance, i.e. Nnorm,inter = Ncarrier-1 and Nreduced,inter =0. The minimum performance requirements for a UE which does not support Increased UE carrier monitoring E-UTRA [16,31] are calculated assuming all E-UTRA carriers required to be monitored for such UE, are having normal performance, i.e. Knorm,E-UTRA = Kcarrier, and Kreduced,E-UTRA =0. Capabilities for number of carriers to monitor for a UE which does not support Increased carrier monitoring E-UTRA or Increased carrier monitoring UTRA are specified in section 4.2.2.8.
4.2.2.1 Measurement and evaluation of cell selection criteria S of serving cell
The UE shall, when eDRX_IDLE is not configured or when eDRX_IDLE cycle is configured and eDRX_IDLE cycle is below or equal to 20.48s, measure the CPICH Ec/Io and CPICH RSCP level of the serving cell and evaluate the cell selection criterion S defined in [1] for the serving cell at least every DRX cycle. The UE shall filter the CPICH Ec/Io and CPICH RSCP measurements of the serving cell using at least 2 measurements. Within the set of measurements used for the filtering, at least two measurements shall be spaced by, at least TmeasureFDD/2 (see table 4.1).
The UE shall, when eDRX_IDLE is configured and eDRX_IDLE cycle is longer than 20.48s, measure the CPICH Ec/Io and CPICH RSCP level of the serving cell and evaluate the cell selection criterion S defined in [1] for the serving cell at least every DRX cycle within the PTW of each eDRX_IDLE cycle. The UE shall filter the CPICH Ec/Io and CPICH RSCP measurements within the PTW of the serving cell using at least 2 measurements. Within the set of measurements used for the filtering, at least two measurements shall be spaced by, at least half of the DRX cycle length.
If the UE, when eDRX_IDLE is not configured or when eDRX_IDLE cycle is configured and eDRX_IDLE cycle is below or equal to 20.48s, has evaluated in Nserv consecutive measured DRX cycles that the serving cell does not fulfil the cell selection criterion S, the UE shall initiate the measurements of all neighbour cells indicated in the measurement control system information, regardless of the measurement rules currently limiting UE measurement activities.
If the UE when eDRX_IDLE is configured and eDRX_IDLE cycle is longer than 20.48s, has evaluated in MIN(Nserv, 
) consecutive measured DRX cycles that the serving cell does not fulfil the cell selection criterion S, the UE shall initiate the measurements of all neighbour cells indicated in the measurement control system information, regardless of the measurement rules currently limiting UE measurement activities.If the UE, independent on if eDRX_IDLE is configured or not, has not found any new suitable cell based on searches and measurements of the neighbour cells indicated in the measurement control system information for 12 s, the UE shall initiate cell selection procedures for the selected PLMN as defined in [1].
After this 12 s period a UE in Cell:PCH or URA_PCH is considered to be "out of service area" and shall perform actions according to 25.331.
On transition from CELL_DCH to CELL_PCH/URA_PCH, if a UE cannot find a suitable UTRA cell, then it is considered to be "out of service area" and shall perform actions according to [16].
If the S criterion of the serving cell is no longer fulfilled, the UE may suspend MBMS reception if necessary to improve the UE’s ability to find a suitable cell.
If the S criterion of the serving cell is fulfilled, the measurement requirements when a MBMS reception is active are specified in sections 4.2.2.2 and 4.2.2.9.
4.2.2.2 Measurements of intra-frequency cells
The UE shall, when eDRX_IDLE is not configured or when eDRX_IDLE cycle is configured and eDRX_IDLE cycle is below or equal to 20.48s, measure CPICH Ec/Io and CPICH RSCP at least every TmeasureFDD (see table 4.1) for intra-frequency cells that are identified and measured according to the measurement rules. TmeasureFDD is defined in Table 4.1. The UE shall filter CPICH Ec/Io and CPICH RSCP measurements of each measured intra-frequency cell using at least 2 measurements. Within the set of measurements used for the filtering, at least two measurements shall be spaced by at least TmeasureFDD/2.
The filtering shall in this case be such that the UE shall be capable of evaluating that an intra-frequency cell has become better ranked than the serving cell within TevaluateFDD (see table 4.1), from the moment the intra-frequency cell became at least 3 dB better ranked than the current serving cell, provided that Treselection timer is set to zero and either CPICH Ec/Io or CPICH RSCP is used as measurement quantity for cell reselection. The UE shall when eDRX_IDLE is configured and eDRX_IDLE cycle is longer than 20.48s, measure CPICH Ec/Io and CPICH RSCP at least 2 times during the PTW every eDRX_IDLE cycle for intra-frequency cells that are identified and measured according to the measurement rules. The UE shall filter CPICH Ec/Io and CPICH RSCP measurements of each measured intra-frequency cell using at least 2 measurements from the same PTW. Within the set of measurements used for the filtering, at least two measurements shall be spaced by at least half the DRX cycle.
The filtering shall in this case be such that the UE shall be capable of evaluating that an intra-frequency cell has become better ranked than the serving cell within one eDRX_IDLE cycle from the moment the intra-frequency cell became at least 3 dB better ranked than the current serving cell, provided that Treselection timer is set to zero and either CPICH Ec/Io or CPICH RSCP is used as measurement quantity for cell reselection.
If Treselection timer has a non zero value and the intra-frequency cell is better ranked than the serving cell, the UE shall evaluate this intra-frequency cell for the Treselection time. If this cell remains better ranked within this duration, then the UE shall reselect that cell.
If the UE is receiving the MTCH, the UE shall to be able to identify new intra-frequency cells and take them into use for MTCH combining purposes as defined in section 8.4.2.2.1
4.2.2.3 Measurements of inter-frequency FDD cells
If priority information for UTRA FDD carrier frequencies is provided in the measurement control systems information and SrxlevServingCell > Sprioritysearch1 and SqualServingCell > Sprioritysearch2 then the UE shall search for any higher priority UTRA inter-frequency cells at least every Thigher_priority_search where Thigher_priority_search is described in section 4.2.2. If the UE is not in CELL_PCH, URA_PCH or IDLE state then the UE shall search for UTRA FDD layers of higher priority within Thigher_layer_start upon entering into any of these states. If 1 second has not elapsed since the UE camped on the current serving cell when the UE enters into any of these states, Thigher_layer_start is one DRX cycle plus 1 second; otherwise Thigher_layer_start is one DRX cycle. If higher priority UTRA cells are found by the higher priority search, they shall be measured when eDRX_IDLE is not configured or is configured with a eDRX_IDLE cycle less than or equal 20.48s at least every (Ncarrier-1) * TmeasureFDD. When eDRX_IDLE is configured with a eDRX_IDLE cycle longer than 20.48s they shall be measured at least with two measurements during the PTW in each eDRX_IDLE cycle. If, after detecting a cell in a higher priority search, it is determined that reselection has not occurred then the UE is not required to continuously measure the detected cell to evaluate the ongoing possibility of reselection. However, the minimum measurement filtering requirements specified later in this section shall still be met by the UE before it makes any determination that it may stop measuring the cell. If priority information for UTRA FDD carrier frequencies is provided in the measurement control systems information and SrxlevServingCell <= Sprioritysearch1 or SqualServingCell <= Sprioritysearch2, the rules defined below apply irrespective of the priority of the inter-frequency layer.
The UE shall, when eDRX_IDLE is not configured or eDRX_IDLE is configured with a eDRX_IDLE cycle less than or equal 20.48s, measure CPICH Ec/Io and CPICH RSCP at least every Nnorm, inter * TmeasureFDD (see table 4.1) for the normal performance group carriers and Nreduced, inter * 6 * TmeasureFDD for the reduced performance group carriers for inter-frequency cells that are identified and measured according to the measurement rules. The parameter Nnorm, inter is the number of carriers in the normal performance group and Nreduced, inter is the number of carriers in the reduced performance group used for FDD cells as defined in section 4.2.2.The UE shall filter CPICH Ec/Io and CPICH RSCP measurements of each measured inter-frequency cell using at least 2 measurements. Within the set of measurements used for the filtering, at least two measurements shall be spaced by at least TmeasureFDD/2.
If CPICH Ec/Io is used as measurement quantity for cell reselection and eDRX_IDLE is not configured or eDRX_IDLE is configured with a eDRX_IDLE cycle less than or equal 20.48s, the filtering shall be such that the UE shall be capable of evaluating that an already identified inter-frequency cell has met the reselection criteria in [1] within Nnorm, inter * TevaluateFDD (see table 4.1) for the normal performance group carriers and Nreduced, inter * 6 * TevaluateFDD for the reduced performance group carriers from the moment the inter-frequency cell met the reselection criteria by at least 3 dB provided that Treselection timer is set to zero. For non-identified inter-frequency cells, the filtering shall be such that the UE shall be capable of evaluating that inter-frequency cell belonging to the normal performance group has met the reselection criteria in [1] within 30 s and inter-frequency cell belonging to the reduced performance group has met the reselection criteria in [1] within 180 s from the moment the inter-frequency cell met the reselection criteria by at least 3 dB provided that Treselection timer is set to zero.
If CPICH RSCP is used as measurement quantity for cell reselection and eDRX_IDLE is not configured or eDRX_IDLE is configured with a eDRX_IDLE cycle less than or equal 20.48s, the filtering shall be such that the UE shall be capable of evaluating that an already identified inter-frequency cell has met the reselection criteria in [1] within Nnorm, inter * TevaluateFDD for the normal performance group carriers and Nreduced, inter * 6 * TevaluateFDD for the reduced performance group carriers from the moment the inter-frequency cell met the reselection criteria by at least 5 dB for reselection based on ranking, or [6]dB for reselection based on absolute priorities provided that Treselection timer is set to zero. For non-identified inter-frequency cells, the filtering shall be such that the UE shall be capable of evaluating that inter-frequency cell belonging to the normal performance group has met the reselection criteria in [1] within 30 s and inter-frequency cell belonging to the reduced performance group has met the reselection criteria in [1] within 180 s from the moment the inter-frequency cell met the reselection criteria by at least 5 dB for reselection based on ranking, or [6]dB for reselection based on absolute priorities provided that Treselection timer is set to zero.
The UE shall when eDRX_IDLE is configured with a eDRX_IDLE cycle longer than 20.48s measure CPICH Ec/Io and CPICH RSCP at least two times during the PTW period in every eDRX_IDLE cycle length for the normal performance group carriers for inter-frequency cells that are identified and measured according to the measurement rules. For the reduced performance group the UE shall, when Srxlev<3 dB or Squal<3 dB measure CPICH Ec/Io and CPICH RSCP at least two times during the PTW cycle in every DRX cycle length. The UE shall filter CPICH Ec/Io and CPICH RSCP measurements of each measured inter-frequency cell using at least 2 measurements from the same PTW. Within the set of measurements used for the filtering, at least two measurements shall be spaced by at least half the DRX cycle length.
If CPICH Ec/Io is used as measurement quantity for cell reselection reselection and eDRX_IDLE is configured with a eDRX_IDLE cycle longer than 20.48s, the filtering shall be such that the UE shall be capable of evaluating that an already identified inter-frequency cell has met the reselection criteria in [1] within one eDRX_IDLE cycle length for the normal performance group carriers and if Srxlev<3 dB or Squal<3 dB one eDRX_IDLE cycle for the reduced performance group carriers from the moment the inter-frequency cell met the reselection criteria by at least 3 dB provided that Treselection timer is set to zero. For non-identified inter-frequency cells, the filtering shall be such that the UE shall be capable of evaluating that inter-frequency cell belonging to the normal performance group has met the reselection criteria in [1] within the MAX(30s, 2*eDRX_IDLE cycle length) and inter-frequency cell belonging to the reduced performance group when Srxlev<3 dB or Squal<3 dB has met the reselection criteria in [1] within MAX(180s, 2*eDRX_IDLE cycle length) from the moment the inter-frequency cell met the reselection criteria by at least 3 dB provided that Treselection timer is set to zero.
If CPICH RSCP is used as measurement quantity for cell reselection and and eDRX_IDLE is configured with a eDRX_IDLE cycle longer than 20.48s, the filtering shall be such that the UE shall be capable of evaluating that an already identified inter-frequency cell has met the reselection criteria in [1] within one eDRX_IDLE cycle length for the normal performance group carriers and if Srxlev<3 dB or Squal<3 dB one eDRX_IDLE cycle for the reduced performance group carriers from the moment the inter-frequency cell met the reselection criteria by at least 5 dB for reselection based on ranking, or 6 dB for reselection based on absolute priorities provided that Treselection timer is set to zero. For non-identified inter-frequency cells, the filtering shall be such that the UE shall be capable of evaluating that inter-frequency cell belonging to the normal performance group has met the reselection criteria in [1] within the MAX(30s,2*eDRX_IDLE cycle length) and inter-frequency cell belonging to the reduced performance group and Srxlev<3 dB or Squal<3 dB has met the reselection criteria in [1] within MAX(180 s, 2*eDRX_IDLE cycle length) from the moment the inter-frequency cell met the reselection criteria by at least 5 dB for reselection based on ranking, or [6]dB for reselection based on absolute priorities provided that Treselection timer is set to zero.
If Treselection timer has a non zero value and the inter-frequency cell meets the reselection criteria in [1], the UE shall evaluate this inter-frequency cell for the Treselection time. If this cell fulfils the reselection criteria within this duration, then the UE shall reselect that cell.
4.2.2.4 Measurements of inter-frequency TDD cells
The requirements in this section shall apply to UE supporting FDD and TDD.
The UE shall, when eDRX_IDLE is not configured or eDRX_IDLE is configured with a eDRX_IDLE cycle less than or equal 20.48s, measure P-CCPCH RSCP at least every NcarrierTDD * TmeasureTDD (see table 4.1) for inter-frequency TDD cells that are identified and measured according to the measurement rules. The parameter NcarrierTDD is the number of carriers used for inter-frequency TDD cells. The UE shall filter P-CCPCH RSCP measurements of each measured inter-frequency TDD cell using at least 2 measurements. Within the set of measurements used for the filtering, at least two measurements shall be spaced by at least TmeasureTDD/2.
The filtering of PCCPCH RSCP shall, when eDRX_IDLE is not configured or eDRX_IDLE is configured with a eDRX_IDLE cycle less than or equal 20.48s, be such that the UE shall be capable of evaluating that an already identified inter-frequency TDD cell has become better ranked than the serving cell within NcarrierTDD* TevaluateTDD from the moment the inter-frequency TDD cell became at least 5 dB better ranked than the current serving cell provided that Treselection timer is set to zero. For non-identified inter-frequency TDD cells, the filtering shall be such that the UE shall be capable of evaluating that an inter-frequency TDD cell has become better ranked than the serving cell within 30 s from the moment the inter-frequency TDD cell became at least 5 dB better ranked than the current serving cell provided that Treselection timer is set to zero.
The UE shall, when eDRX_IDLE is configured with a eDRX_IDLE cycle longer than 20.48s, measure P-CCPCH RSCP at least two times during the PTW in every eDRX_IDLE cycle length for inter-frequency TDD cells that are identified and measured according to the measurement rules. The UE shall filter P-CCPCH RSCP measurements of each measured inter-frequency TDD cell using at least 2 measurements from the same PTW. Within the set of measurements used for the filtering, at least two measurements shall be spaced by at least half the DRX cycle length.
The filtering of PCCPCH RSCP shall when eDRX_IDLE is configured with a eDRX cycle longer than 20.48s be such that the UE shall be capable of evaluating that an already identified inter-frequency TDD cell has become better ranked than the serving cell within one eDRX_IDLE cycle length from the moment the inter-frequency TDD cell became at least 5 dB better ranked than the current serving cell provided that Treselection timer is set to zero. For non-identified inter-frequency TDD cells, the filtering shall be such that the UE shall be capable of evaluating that an inter-frequency TDD cell has become better ranked than the serving cell within the minimum of 30s and two times the eDRX_IDLE cycle length from the moment the inter-frequency TDD cell became at least 5 dB better ranked than the current serving cell provided that Treselection timer is set to zero.
If Treselection timer has a non zero value and the inter-frequency TDD cell is better ranked than the serving cell, the UE shall evaluate this inter-frequency TDD cell for the Treselection time. If this cell remains better ranked within this duration, then the UE shall reselect that cell.
4.2.2.5 Measurements of inter-RAT GSM cells
4.2.2.5.1 Cell reselection based on cell ranking
The requirements in this subclause shall apply if the UE uses the cell ranking algorithm for inter-RAT cell reselection [1].
The UE shall, when eDRX_IDLE is not configured or eDRX is configured with a eDRX_IDLE cycle less than or equal 20.48s, measure the signal level of the GSM BCCH carrier of each GSM neighbour cell indicated in the measurement control system information of the serving cell, according to the measurement rules defined in [1], at least every TmeasureGSM (see table 4.1). The UE shall maintain a running average of 4 measurements for each GSM BCCH carrier. The measurement samples for each cell shall be as far as possible uniformly distributed over the averaging period.
The UE shall, when eDRX_IDLE is configured with a eDRX_IDLE cycle longer than 20.48s, measure the signal level of the GSM BCCH carrier of each GSM neighbour cell indicated in the measurement control system information of the serving cell, according to the measurement rules defined in [1], at least two times every eDRX_IDLE cycle length. The UE shall in the PTW in every eDRX_IDLE cycle calculate an average of 4 measurement samples for each GSM BCCH carrier. The measurement samples for each cell shall as far as possible be uniformly distributed over the averaging period.
If GSM measurements are required by the measurement rules in [1], the UE shall attempt to verify the BSIC at least every MAX(30 seconds, eDRX_IDLE cycle length) for each of the 4 strongest GSM BCCH carriers and rank the verified GSM BCCH cells according to the cell reselection criteria defined in [1]. If a change of BSIC is detected for one GSM cell then that GSM BCCH carrier shall be treated as a new GSM neighbour cell.
If the UE detects a BSIC, which is not indicated in the measurement control system information, the UE shall not consider that GSM BCCH carrier in cell reselection. The UE also shall not consider the GSM BCCH carrier in cell reselection, if the UE cannot demodulate the BSIC of that GSM BCCH carrier.
If Treselection timer has a non zero value and the inter-RAT GSM cell is better ranked than the serving cell, the UE shall evaluate this inter-RAT GSM cell for the Treselection time. If this cell remains better ranked within this duration, then the UE shall reselect that cell.
4.2.2.5.2 Cell reselection based on priority information
The requirements in this subclause shall apply if the UE uses the absolute priorities based algorithm for inter-RAT cell reselection [1].
If SrxlevServingCell > Sprioritysearch1 and SqualServingCell > Sprioritysearch2 then the UE shall search for and measure GSM cells if the priority of GSM is higher than the serving cell. The minimum rate at which the UE is required to search for and measure such layers may be reduced in this scenario to maintain UE battery life.
When the measurement rules defined in [1] indicate that inter-RAT cells are to be measured then the UE shall measure, the signal level of the GSM BCCH carriers if the GSM BCCH carriers are indicated in the measurement control system information of the serving cell. GSM BCCH carriers of lower priority than the serving cell shall when eDRX_IDLE_IDLE is not configured or eDRX_IDLE is configured with a eDRX_IDLE cycle less than or equal 20.48s be measured at least every Tmeasure,GSM (see table 4.1). When eDRX_IDLE is configured with a eDRX_IDLE cycle longer than 20.48s serving cell shall be measured at least 4 times during the PTW within every eDRX_IDLE cycle length.
If SrxlevServingCell > Sprioritysearch1 and SqualServingCell > Sprioritysearch2 then the UE shall search for GSM BCCH carrier at least every Thigher_priority_search where Thigher_priority_search is described in section 4.2.2. If the UE is not in CELL_PCH, URA_PCH or IDLE state then the UE shall search for GSM layers of higher priority within Thigher_layer_start upon entering into any of these states. If 1 second has not elapsed since the UE camped on the current serving cell when the UE enters into any of these states, Thigher_layer_start is one DRX cycle plus 1 second; otherwise Thigher_layer_start is one DRX cycle. When higher priority GSM BCCH carriers are found by the higher priority search when eDRX_IDLE is not configured or eDRX_IDLE is configured with a eDRX_IDLE cycle less than or equal 20.48s, they shall be measured at least every Tmeasure,GSM, and the UE shall decode the BSIC of the GSM BCCH carrier. When eDRX_IDLE is configured with a eDRX_IDLE cycle longer than 20.48s, they shall be measured at least 4 times during the PTW in every eDRX_IDLE cycle length, and the UE shall decode the BSIC of the GSM BCCH carrier.
If, after detecting a cell in a higher priority search, it is determined that reselection has not occurred then the UE is not required to continuously measure the detected cell to evaluate the ongoing possibility of reselection to continuously verify the BSIC of the GSM BCCH carrier every MIN(30s, eDRX_IDLE cycle length). However, the minimum measurement filtering requirements specified later in this section shall still be met by the UE before it makes any determination that it may stop measuring the cell. If SrxlevServingCell <= Sprioritysearch1 or SqualServingCell <= Sprioritysearch2, the rules defined below apply irrespective of the priority of the GSM layer.
The UE shall when eDRX_IDLE is not configured or eDRX_IDLE is configured with a eDRX_IDLE cycle less than or equal 20.48s maintain a running average of 4 measurements for each GSM BCCH carrier. The measurement samples for each cell shall be as far as possible uniformly distributed over the averaging period. The UE shall when eDRX_IDLE is configured with a eDRX_IDLE cycle longer than 20.48s every eDRX_IDLE cycle length measure and average of 4 measurements for each GSM BCCH carrier. The measurement samples for each cell shall be as far as possible uniformly distributed over the averaging period.
If continuous GSM measurements are required by the measurement rules in [1], the UE shall attempt to verify the BSIC at least every MIN(30 seconds, eDRX_IDLE cycle length) for each of the 4 strongest GSM BCCH carriers. If a change of BSIC is detected for one GSM cell then that GSM BCCH carrier shall be treated as a new GSM neighbour cell. If the UE detects on a BCCH carrier a BSIC which is indicated as not allowed for that carrier in the measurement control system information of the serving cell, the UE is not required to perform BSIC re-confirmation for that cell.
The UE shall not consider the GSM BCCH carrier in cell reselection, if the UE cannot demodulate the BSIC of that GSM BCCH carrier. Additionally, the UE shall not consider a GSM neighbour cell in cell reselection, if it is indicated as not allowed in the measurement control system information of the serving cell.
4.2.2.5a Measurements of inter-RAT E-UTRA cells
The UE shall be able to identify new E-UTRA cells and perform RSRP and RSRQ measurements of identified E-UTRA cells if carrier frequency information is provided by the serving cell, even if no explicit neighbour list with physical layer cell identities is provided.
If SrxlevServingCell > Sprioritysearch1 and SqualServingCell > Sprioritysearch2 then the UE shall search for E-UTRA layers of higher priority at least every Thigher_priority_search where Thigher_priority_search is described in section 4.2.2. If the UE is not in CELL_PCH, URA_PCH or IDLE state then the UE shall search for E-UTRA layers of higher priority within Thigher_layer_start upon entering into any of these states. If 1 second has not elapsed since the UE camped on the current serving cell when the UE enters into any of these states, Thigher_layer_start is one DRX cycle plus 1 second; otherwise Thigher_layer_start is one DRX cycle. The minimum rate at which the UE is required to search for and measure such layers may be reduced in this scenario to maintain UE battery life.
If SrxlevServingCell <= Sprioritysearch1 or SqualServingCell <= Sprioritysearch2 then the UE shall search for and measure E-UTRA frequency layers of higher or lower priority in preparation for possible reselection. In this scenario, the minimum rate at which the UE is required to search for and measure higher priority layers shall be the same as that defined below for a lower priority layers.
The UE shall, when eDRX_IDLE is not configured or eDRX_IDLE is configured with a eDRX_IDLE cycle less than or equal 20.48s, be able to evaluate whether a new detectable lower priority inter-RAT E-UTRA cell meets the reselection criteria defined in [1] within Knorm, EUTRA * TdetectE-UTRA for the normal performance group and Kreduced, EUTRA * 6 * TdetectE-UTRA for the reduced performance group, where TdetectE-UTRA is given in Table 4.2, if E-UTRA carrier frequency information is provided in the inter-RAT measurement control system information when Treselection=0 provided that the reselection criteria is met by at least 6dB for RSRP reselections or 4dB for RSRQ reselections. The parameter Knorm, EUTRA is the number of E-UTRA carrier frequencies in the normal performance group and the parameter Kreduced, EUTRA is the number of E-UTRA carrier frequencies in the reduced performance group indicated in the inter-RAT measurement control system information as defined in section 4.2.2. An inter RAT E-UTRAN cell is considered to be detectable if:
– RSRP|dBm according to Annex B.1.1 for a corresponding Band
The UE shall measure RSRP and RSRQ at least every Knorm, EUTRA * TmeasureE-UTRA for normal performance group and Kreduced, EUTRA * 6 * TmeasureE-UTRA for reduced performance group as defined in table 4.2 for identified E-UTRA cells.
The UE shall when eDRX_IDLE is configured with a eDRX_IDLE cycle longer than 20.48s for the normal performance group and if Srxlev<3 dB or Squal<3 dB for the reduced performance group be able to evaluate whether a new detectable lower priority inter-RAT E-UTRA cell meets the reselection criteria defined in [1] within the PTW in every eDRX_IDLE cycle length if E-UTRA carrier frequency information is provided in the inter-RAT measurement control system information when Treselection=0 provided that the reselection criteria is met by at least 6dB for RSRP reselections or 4dB for RSRQ reselections. An inter RAT E-UTRAN cell is considered to be detectable when eDRX_IDLE is configured with a eDRX_IDLE cycle longer than 20.48s if:
– RSRP|dBm according to Annex B.1.1 for a corresponding Band
The UE shall measure RSRP and RSRQ at least 2 times every eDRX_IDLE cycle time for normal performance group and if Srxlev<3 dB or Squal<3 dB for reduced performance group.
When higher priority cells are found by the higher priority search when eDRX_IDLE is not configured or eDRX is configured with a eDRX_IDLE cycle less than or equal 20.48s, they shall be measured at least every TmeasureE-UTRA. When higher priority cells are found by the higher priority search when eDRX_IDLE is configured with a eDRX_IDLE cycle longer than 20.48s, they shall be measured at least two times during the PTW in every eDRX_IDLE cycle time. If, after detecting a cell in a higher priority search, it is determined that reselection has not occurred then the UE is not required to continuously measure the detected cell to evaluate the ongoing possibility of reselection. However, the minimum measurement filtering requirements specified later in this section shall still be met by the UE before it makes any determination that it may stop measuring the cell. If the UE detects on a E-UTRA carrier a cell whose physical identity is indicated as not allowed for that carrier in the measurement control system information of the serving cell, the UE is not required to perform measurements on that cell.
If the UE detects on a E-UTRA carrier a cell whose physical identity is indicated as not allowed for that carrier in the measurement control system information of the serving cell, the UE is not required to perform measurements on that cell.
The UE shall filter RSRP and RSRQ measurements of each measured E-UTRA cell using at least 2 measurements. Within the set of measurements used for the filtering when eDRX_IDLE is not configured or eDRX_IDLE is configured with a eDRX_IDLE cycle less than or equal 20.48s, at least two measurements shall be spaced by at least TmeasureE-UTRA/2. When eDRX_IDLE is configured with a eDRX_IDLE cycle longer than 20.48s the UE shall filter RSRP and RSRQ measurements of each measured E-UTRA cell using at least 2 measurements from the PTW within a eDRX_IDLE cycle length. Within this set of measurements used for the filtering, at least two measurements shall be spaced by at least half the DRX cycle.
RSRP and RSRQ measurements of E-UTRA cells shall not be filtered over a longer period than that specified in Table 4.2.
The UE shall not consider an E-UTRA neighbour cell in cell reselection, if it is indicated as not allowed in the measurement control system information of the serving cell.
For an inter-RAT E-UTRA cell that has been already detected, but that has not been reselected to, the filtering shall be such that the UE shall when eDRX_IDLE is not configured or eDRX_IDLE is configured with a eDRX_IDLE cycle less than or equal 20.48s be capable of evaluating that the E-UTRA cell has met reselection criterion defined TS 36.304 within Knorm, EUTRA * TevaluateEUTRA for normal performance group and Kreduced, EUTRA * 6 * TevaluateE-UTRA for reduced performance group as specified in table 4.2 provided that the reselection criteria is met by at least 6dB for RSRP reselections or 4dB for RSRQ reselections and the Treselection timer is set to zero. When eDRX_IDLE is configured with a eDRX_IDLE cycle longer than 20.48s the filtering shall be such that the UE shall be capable of evaluating that the E-UTRA cell has met reselection criterion defined TS 36.304 within one eDRX_IDLE cycle length for normal performance group and for reduced performance group when Srxlev<3 dB or Squal<3 dB provided that the reselection criteria is met by at least 6dB for RSRP reselections or 4dB for RSRQ reselections and the Treselection timer is set to zero.
4.2.2.6 Evaluation of cell re-selection criteria
The UE shall evaluate the cell re-selection criteria defined in TS 25.304 for the cells, which have new measurement results available, at least every DRX cycle.
UE shall perform cell reselection immediately after the reselection criteria have been met (e.g. the UE has found a higher ranked suitable cell or the UE has found a suitable cell on a higher priority RAT), unless less than 1 second has elapsed from the moment the UE started camping on the serving cell. The ranking of the cells shall be made according to the cell reselection criteria specified in TS25.304.
4.2.2.7 Maximum interruption in paging reception
UE shall perform the cell re-selection with minimum interruption in monitoring downlink channels for paging reception.
At intra-frequency cell re-selection, the UE shall monitor the downlink of serving cell for paging reception until the UE is capable to start monitoring downlink channels of the target intra-frequency cell for paging reception. The interruption time shall not exceed 50 ms.
At inter-frequency and inter-RAT cell re-selection, the UE shall monitor the downlink of serving cell for paging reception until the UE is capable to start monitoring downlink channels for paging reception of the target inter-frequency cell. For inter-frequency cell re-selection the interruption time must not exceed – TSI + 50 ms. For inter-RAT cell re-selection the interruption time must not exceed TBCCH + 50 ms for GSM or TSI-EUTRA + [50 ms] for E-UTRA.
TSI is the time required for receiving all the relevant system information data according to the reception procedure and the RRC procedure delay of system information blocks defined in 25.331 for a UTRAN cell.
TBCCH is the maximum time allowed to read BCCH data from a GSM cell [21].
TSI-EUTRA is the maximum time allowed to read system information from a E-UTRA cell [24].
These requirements assume sufficient radio conditions, so that decoding of system information can be made without errors and does not take into account cell re-selection failure.
Table 4.1: TmeasureFDD, TevaluateFDD, TmeasureTDD, TevaluateTDD, and TmeasureGSM
|
DRX cycle length [s] |
Nserv [number of DRX cycles] |
TmeasureFDD [s] (number of DRX cycles) |
TevaluateFDD [s] (number of DRX cycles) |
TmeasureTDD [s] (number of DRX cycles) |
TevaluateTDD [s] (number of DRX cycles) |
TmeasureGSM [s] (number of DRX cycles) |
|
0.08 |
4 |
0.64 (8 DRX cycles) |
2.56 (32 DRX cycles) |
0.64 (8 DRX cycles) |
2.56 (32 DRX cycles) |
2.56 (32 DRX cycles) |
|
0.16 |
4 |
0.64 (4) |
2.56 (16) |
0.64 (4) |
2.56 (16) |
2.56 (16) |
|
0.32 |
4 |
1.28 (4) |
5.12 (16) |
1.28 (4) |
5.12 (16) |
5.12 (16) |
|
0.64 |
4 |
1.28 (2) |
5.12 (8) |
1.28 (2) |
5.12 (8) |
5.12 (8) |
|
1.28 |
2 |
1.28 (1) |
6.4 (5) |
1.28 (1) |
6.4 (5) |
6.4 (5) |
|
2.56 |
2 |
2.56 (1) |
7.68 (3) |
2.56 (1) |
7.68 (3) |
7.68 (3) |
|
5.12 |
1 |
5.12 (1) |
10.24 (2) |
5.12 (1) |
10.24 (2) |
10.24 (2) |
Table 4.2: TdetectE-UTRA, TmeasureE-UTRA and TevaluateEUTRA
|
DRX cycle length [s] |
TdetectE-UTRA [s] |
TmeasureE-UTRA [s] (number of DRX cycles) |
TevaluateEUTRA [s] (number of DRX cycles) |
|
0.08 |
30 |
2.56 (32) |
7.68 (96) |
|
0.16 |
2.56 (16) |
7.68 (48) |
|
|
0.32 |
5.12 (16) |
15.36 (48) |
|
|
0.64 |
5.12 (8) |
15.36 (24) |
|
|
1.28 |
6.4 (5) |
19.2 (15) |
|
|
2.56 |
60 |
7.68 (3) |
23.04 (9) |
|
5.12 |
10.24 (2) |
30.72 (6) |
For higher priority cells, a UE may optionally use a shorter value for TmeasureFDD and TmeasureE-UTRA ,which shall not be less than Max(0.64 s, one DRX cycle).
In idle mode, UE shall support DRX cycles lengths 0.64, 1.28, 2.56 and 5.12 s, according to [16] and UE shall, if it supports eDRX_IDLE, support eDRX_IDLE cycle lengths 10.24, 20.48, 40.96, 81.92, 163.84, 327.68, 655.36,1310.72, 1966.08 and 2621.44 seconds, according to TS 24.008 [32].
4.2.2.8 Number of cells in cell lists
For idle mode cell re-selection purposes, the UE shall be capable of monitoring:
– 32 intra-frequency cells (including serving cell), and
– 32 inter-frequency cells, including
– FDD cells on maximum 2 additional carriers, and
– Depending on UE capability, TDD cells distributed on up to 3 TDD carriers, and
– Depending on UE capability, 32 GSM cells distributed on up to 32 GSM carriers, and
– Depending on UE capability, up to 4 E-UTRA FDD carriers, and
– Depending on UE capability up to 4 E-UTRA TDD carriers
as indicated in cell information lists sent in system information (BCCH).
In addition to the requirements defined above, a UE supporting E-UTRA measurements in RRC_IDLE state shall be capable of monitoring a minimum total of at least 8 carrier frequency layers, including the intra-frequency serving layer and comprising of any above defined combination of E-UTRA FDD, E-UTRA TDD, UTRA FDD, UTRA TDD and GSM layers (one GSM layer corresponds to 32 cells).
4.2.2.8a Number of cells in cell lists (Increased UE carrier monitoring)
UE which supports Increased UE carrier monitoring UTRA according to capabilities in [16,31] shall be capable of monitoring at least
80 inter-frequency cells, including
– 5 FDD UTRA inter-frequency carriers with up to 32 cells per carrier.
UE which supports increased UE carrier monitoring E-UTRA according to capabilities in [16,31] shall be capable of monitoring at least
– Depending on UE capability, 8 FDD E-UTRA carriers, and
– Depending on UE capability, 8 TDD E-UTRA carriers, and
In addition to the requirements defined above, a UE supporting E-UTRA measurements in RRC_IDLE state and supporting Increased UE carrier monitoring UTRA or increased UE carrier monitoring E-UTRA according to capabilities in [16,31] shall be capable of monitoring a total of at least 13 carrier frequency layers, which includes serving layer, comprising of any above defined combination of of E-UTRA FDD, E-UTRA TDD, UTRA FDD, UTRA TDD and GSM layers (one GSM layer corresponds to 32 cells).
4.2.2.9 Additional requirements for measurement of inter-frequency and inter-RAT cells when MBMS reception is active
If an MBMS service is being received then the following requirements additionally apply:
When the UE is receiving MTCH and the UE evaluates that the cell re-selection measurement rules in 25.304 indicate that inter-frequency or inter-RAT measurements are not required to be made, the UE shall not perform the corresponding inter-frequency or inter-RAT measurements.
When the UE is receiving MTCH and the UE evaluates that the cell re-selection measurement rules in 25.304 indicate that inter-frequency or inter-RAT measurements are required to be made, and the UE needs to interrupt MTCH reception to make inter-frequency or inter-RAT measurements, an individual interruption of MTCH reception shall not exceed 12.5% of an MTCH TTI from a single arbitrary cell from which the MTCH is received.
The total interruption time to the MTCH reception due to inter-frequency measurements shall not exceed a total of
– 20 ms every Tmeasure, FDD for measuring known FDD inter-frequency neighbours, and
– 300 ms every 30 seconds for searching for new FDD inter-frequency cells for each inter-frequency carrier frequency
There are no corresponding limitations on the total interruption time to the MTCH reception due to inter-RAT measurements
The UE shall ensure that inter-frequency measurement or inter-RAT measurement interruptions do not overlap constantly with the periodic MCCH transmissions.
4.2.2.10 MTCH Interruption time
The MTCH interruption time is the time between the end of the last MTCH TTI on which UE receives MTCH from the serving cell and the beginning of the first MTCH TTI on which UE starts receiving MTCH from the target cell.
The MTCH interruption time due to intra-frequency cell reselection without soft combining during an MBMS session shall be less than TMTCH_interrupt
TMTCH_interrupt = TIU+20 +TMCCH+TMTCH ms
Where
TMCCH: is the time required to read the relevant MCCH information of the target cell according to the MBMS specific procedures defined in TS 25.331.
TMTCH: is the uncertainty when reading the MTCH of the serving and target cells while performing cell reselection; TMTCCH can be up to 2 MTCH TTI.
The MTCH interruption time (TMTCH_interrupt) shall be applicable when UE is receiving MBMS in idle mode, CELL_PCH state and URA_PCH state.
4.2.2.11 Reselection to CSG cells
Note: Requirements in this section are minimum requirements defined to ensure the testability of autonomous CSG search.
Reselection from non CSG to CSG cells may be performed using UE autonomous search as defined in [1] when at least one CSG ID is included in the UE’s CSG whitelist. The requirements in this section are valid for reselection to CSG cells previously visited by the UE when the radio configuration parameters, including the carrier frequency and physical cell identity of the CSG cell, non CSG cell and other neighbour cells are unchanged from the most recent previous visit.
NOTE: According to [1], the UE autonomous search function, per UE implementation, determines when and/or where to search for allowed CSG cells.
4.2.2.11.1 Reselection from a non CSG to an inter-frequency CSG cell
The UE shall perform search and reselection to an allowed inter-frequency CSG cell that has met CSG reselection criterion defined in [1] and that is in its whitelist, within 6 minutes in the conditions shown in table 4.2.2.11.1-1. There is no need for statistical testing of this requirement.
Table 4.2.2.11.1-1: Parameters for CSG inter-frequency reselection
|
Parameter |
Unit |
Cell 1 |
Cell 2 |
|
|
UARFCN Note1 |
Channel 1 |
Channel 2 |
||
|
CSG indicator |
False |
True |
||
|
Primary scrambling code Note1 |
Scrambling code 1 |
Scrambling code 2 |
||
|
CSG identity |
Not sent |
Sent (Already stored in UE whitelist from previous visit) |
||
|
Propagation conditions |
Static, non multipath |
|||
|
CSG cell previously visited by UE |
Yes |
|||
|
CPICH_RSCPNote2 |
dBm |
-100 |
-100 |
|
|
CPICH_Ec/Ior |
dB |
-10 |
-10 |
|
|
PCCPCH_Ec/Ior |
dB |
-12 |
-12 |
|
|
SCCPCH_Ec/Ior |
dB |
-12 |
-12 |
|
|
AICH_Ec/Ior |
dB |
-15 |
-15 |
|
|
SCH_Ec/Ior |
dB |
-15 |
-15 |
|
|
PICH_Ec/Ior |
dB |
-15 |
-15 |
|
|
|
dBm/3.84 MHz |
Off |
Off |
|
|
Note 1: For this requirement to be applicable, the UARFCN and scrambling code for cell 1 and cell 2 shall be unchanged from when the CSG cell was visited previously. Note 2: Chosen to ensure that CSG autonomous search has a high probability of success on every attempt made by UE. |
||||
4.2.2.11.2 Reselection from a non CSG to an inter-RAT E-UTRA CSG cell
The UE shall perform search and reselection to an allowed inter-RAT E-UTRA CSG cell that has met CSG reselection criterion defined in [1] and that is in its whitelist, within 6 minutes in the conditions shown in table 4.2.2.11.2-1. There is no need for statistical testing of this requirement.
Table 4.2.2.11.2-1: Parameters for CSG inter-RAT E-UTRA reselection
|
Parameter |
Unit |
Cell 1 |
Cell 2 |
|
|
UARFCN Note1 |
Channel 1 |
N/A |
||
|
EARFCN Note1 |
N/A |
Channel 2 |
||
|
CSG indicator |
False |
True |
||
|
Primary scrambling code Note1 |
Scrambling |
N/A |
||
|
Physical cell identityNote1 |
N/A |
2 |
||
|
CSG identity |
Not sent |
Sent (Already stored in UE whitelist from previous visit) |
||
|
Propagation conditions |
Static, non multipath |
|||
|
CSG cell previously visited by UE |
Yes |
|||
|
CPICH_RSCPNote2 |
dBm |
-100 |
N/A |
|
|
CPICH_Ec/Ior |
dB |
-10 |
||
|
PCCPCH_Ec/Ior |
dB |
-12 |
||
|
SCCPCH_Ec/Ior |
dB |
-12 |
||
|
AICH_Ec/Ior |
dB |
-15 |
||
|
SCH_Ec/Ior |
dB |
-15 |
||
|
PICH_Ec/Ior |
dB |
-15 |
||
|
|
dBm/3.84 MHz |
Off |
||
|
PBCH_RA |
dB |
N/A |
0 |
|
|
PBCH_RB |
dB |
|||
|
PSS_RA |
dB |
|||
|
SSS_RA |
dB |
|||
|
PCFICH_RB |
dB |
|||
|
PHICH_RA |
dB |
|||
|
PHICH_RB |
dB |
|||
|
PDCCH_RA |
dB |
|||
|
PDCCH_RB |
dB |
|||
|
PDSCH_RA |
dB |
|||
|
PDSCH_RB |
dB |
|||
|
OCNG_RANote 1 |
dB |
|||
|
OCNG_RBNote 1 |
dB |
|||
|
Qrxlevmin |
dBm |
-140 |
||
|
|
dBm/15 kHz |
Off |
||
|
RSRP Note2 |
dBm/15 KHz |
-110 |
||
|
Note 1: For this requirement to be applicable, the UARFCN and scrambling code for cell 1 and the EARFCN and physical cell identity for cell 2 shall be unchanged from when the CSG cell was visited previously Note 2: Chosen to ensure that CSG autonomous search has a high probability of success on every attempt made by UE |
||||
4.3 MBSFN cluster selection
4.3.1 Introduction
MBSFN allows the UE to select a suitable MBSFN cluster where to camp on in order to access available services.
4.4 MBSFN cluster reselection
4.4.1 Introduction
There are no requirements specified for MBSFN cluster reselection.
4.5 Minimization of Drive Tests (MDT)
UE supporting minimisation of drive tests shall be capable of, 3GPP TS 25.331 [16]:
– logging measurements in RRC_IDLE, CELL_PCH, and URA_PCH states, reporting the logged measurements and meeting requirements in this section.
– logging of RRC connection establishment failure, reporting the logged failure and meeting requirements in this section.
4.5.1 Introduction
The loggeed MDT requirements consist of measurement requirements as specified in section 4.5.2 and relative time stamp accuracy requirements as specified in section 4.5.3. Both sets of requirements are applicable for intra-frequency, inter-frequency and inter-RAT cases in idle, CELL_PCH and URA_PCH states. The MDT procedures are described in 3GPP TS 37.320 [26].
For RRC connection establishment failure logging and reporting, the MDT requirements consist of requirements for measurements performed and logged in IDLE, CELL_PCH, and URA_PCH states specified in Section 4.5.2 and relative time stamp accuracy requirement for RRC connection establishment failure log reporting as specified in Section 4.5.4.
4.5.2 Measurements
The requirements specified in this section apply for the measurements (GSM carrier RSSI, UTRA CPICH RSCP, UTRA CPICH Ec/Io, P-CCPCH RSCP for UTRA 1.28 TDD , E-UTRA RSRP and E-UTRA RSRQ) performed and logged by the UE for MDT in IDLE, CELL_PCH and URA_PCH states. The requirements apply for the measurements included in logged MDT reports and RRC connection establishment failure reports.
4.5.2.1 Requirements
The measurement values that are used to meet serving cell and reselection requirements as specified in sections 4.2.2.1, 4.2.2.2, 4.2.2.3, 4.2.2.4, 4.2.2.5 and 4.2.2.5a shall also apply to the values logged for MDT measurements in idle state.
The measurement values that are used to meet serving cell and reselection requirements as specified in section 5.6 shall also apply to the values logged for MDT measurements in CELL_PCH state.
The measurement values that are used to meet serving cell and reselectionrequirements as specified in section 5.7 shall also apply for the values logged for MDT measurements in URA_PCH state.
4.5.3 Relative Time Stamp Accuracy
The relative time stamp for a logged measurement is defined as the time from the moment the MDT configuration was received at the UE until the measurement was logged, see [16].
4.5.3.1 Requirements
The accuracy of the relative time stamping is such that the drift of the time stamping shall be not more than ±2 seconds per hour.
4.5.4 Relative Time Stamp Accuracy for RRC Connection Establishment Failure Log Reporting
Relative time stamp for RRC connection establishment failure log reporting is defined as the time elapsed from the last RRC connection establishment failure to the time when the log is included in the report [16]. The UE shall report the RRC connection establishment failure log, while meeting the accuracy requirement specified in Section 4.5.4.1.
4.5.4.1 Requirements
The accuracy of the relative time stamping for RRC connection establishment failure log reporting is such that the drift of the time stamping shall not be larger than ± 0.72 seconds per hour and ± 10 seconds over 48 hours. The relative time stamp accuracy requirements shall apply provided that:
– no switch off or detach occurs after the RRC connection establishment failure had been detected and until the log is time-stamped.
NOTE: This requirement does not need to be tested.