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4G/LTE - Measurement |
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Multi Cell Measurement
This page will explain about various aspect of Measurement Process that is happening in a LTE. In any technology, Measurement is done roughly at two stage. One is measurement in Idle mode and the other one is in Connected mode. Idle mode measurement is mainly for Cell Selection and Reslection process and most of idle mode measurement criteria is determined by SIB messages, the connected mode measurement is mostly for Handover or CSFB and the measurement criteria is determined by specific RRC messages dedicated for a specific UE.
This page will deal with connected mode measurement process only. Idle mode measurement is not the scope of this page.
In terms of RRC Message, you may say Measurement Process would be a simple one, that is, i) eNB sends an RRC message indicating what kind of items to be measured and ii) UE sends an RRC message that carries the result of the measurement You're right at the high level, but you will find it very tricky if you are asked to create the RRC message with all the detailed parameters (IE : Information Elements) to trigger UE to perform the specific measurement. There are so many details you need to understand.
On UE protocol stack as well, implmentating the measurement process would be one of the most challenging item. According to my experience, it tend to take huge time and effort to implement all sorts of measurement algorithm and take a lot of time for verification process as well.
Topics on this page are as follows.
LTE Measurement Report Trigger (EVENT for Measurement Report)
One of the most important step for Handover is Measurement Report from UE before the handover. Network make a decision on whether it will let UE handover or not, based on the measurement value from UE. There are many different measurement items and many different ways to measure the signal quality of the current cell (serving cell) and target cell.
Ideally a network let UE to report the signal quality (usually RSRP) of the current cell (serving cell) and target cell and set the arbitrary rule for handover. But this can be too complicated and too much load on network since the network may need a multiple times of consecutive measurement result in stead of using only a single or a couple of measured signal quality value (Can you think of why only one or a couple of signal quality measurement (RSRP) would not be a good enough for this kind of decision making ?). As a kind of solution, 3GPP defines several set of predefined set of measurement report mechanism to be performed by UE. These predefined measurement report type is called "Event". What kind of "event" a UE has to report is specified by RRC Connection Reconfiguration message as follows (shown in red).
+-rrcConnectionReconfiguration ::= SEQUENCE +-rrc-TransactionIdentifier ::= INTEGER (0..3) [0] +-criticalExtensions ::= CHOICE [c1] +-c1 ::= CHOICE [rrcConnectionReconfiguration-r8] +-rrcConnectionReconfiguration-r8 ::= SEQUENCE [100000] +-measConfig ::= SEQUENCE [01010111111] OPTIONAL:Exist | +-measObjectToRemoveList ::= SEQUENCE OF OPTIONAL:Omit | +-measObjectToAddModList ::= SEQUENCE OF SIZE(1..maxObjectId[32]) [1] | | +-MeasObjectToAddMod ::= SEQUENCE | | +-measObjectId ::= INTEGER (1..maxObjectId[32]) [1] | | +-measObject ::= CHOICE [measObjectEUTRA] | | +-measObjectEUTRA ::= SEQUENCE [100000] | | +-carrierFreq ::= INTEGER (0..maxEARFCN[65535]) [6300] | | +-allowedMeasBandwidth ::= ENUMERATED [mbw25] | | +-presenceAntennaPort1 ::= BOOLEAN [FALSE] | | +-neighCellConfig ::= BIT STRING SIZE(2) [01] | | +-offsetFreq ::= ENUMERATED [dB0] OPTIONAL:Exist | | +-cellsToRemoveList ::= SEQUENCE OF OPTIONAL:Omit | | +-cellsToAddModList ::= SEQUENCE OF OPTIONAL:Omit | | +-blackCellsToRemoveList ::= SEQUENCE OF OPTIONAL:Omit | | +-blackCellsToAddModList ::= SEQUENCE OF OPTIONAL:Omit | | +-cellForWhichToReportCGI ::= INTEGER OPTIONAL:Omit | +-reportConfigToRemoveList ::= SEQUENCE OF OPTIONAL:Omit | +-reportConfigToAddModList ::= SEQUENCE OF SIZE(1..maxReportConfigId[32]) [1] | | +-ReportConfigToAddMod ::= SEQUENCE | | +-reportConfigId ::= INTEGER (1..maxReportConfigId[32]) [1] | | +-reportConfig ::= CHOICE [reportConfigEUTRA] | | +-reportConfigEUTRA ::= SEQUENCE | | +-triggerType ::= CHOICE [event] | | | +-event ::= SEQUENCE | | | +-eventId ::= CHOICE [eventA3] | | | | +-eventA3 ::= SEQUENCE | | | | +-a3-Offset ::= INTEGER (-30..30) [0] | | | | +-reportOnLeave ::= BOOLEAN [FALSE] | | | +-hysteresis ::= INTEGER (0..30) [0] | | | +-timeToTrigger ::= ENUMERATED [ms640] | | +-triggerQuantity ::= ENUMERATED [rsrp] | | +-reportQuantity ::= ENUMERATED [both] | | +-maxReportCells ::= INTEGER (1..maxCellReport[8]) [1] | | +-reportInterval ::= ENUMERATED [ms1024] | | +-reportAmount ::= ENUMERATED [r1]
Brief description you can find from 3GPP 36.331 5.5.4 Measurement report triggering is as follows. You will see pretty complicated description of the exact procedure of each of these events, but if you convert those descriptions into a graphical format it would be much easier/intuitive to understand the nature of these events.
NOTE : If you speak / understand Korean, you may refer to this YouTube by Sean Mobile Channel(@00:00)
Following is an illustration showing possible conditions triggering each of the events A1~A6. Just suppose that you become a UE and generating measurement report following along the timeline. If you don't get confused, you are high quality UE :)
Simply put, Measurement Report is triggered by whether the measured value crosses (goes higher or goes lower) a certain target value. The target value can be set by one of two methods. One is to use threshold which is a kind of absolute value and the other one is to use Offsef value which is a kind relative value with a reference to 'something' like serving cell value. However, in reality the measured value can fluctuate pretty frequently sometimes by measurement error by UE modem and sometimes by the fluctuation of Radio channel itself. In most case, the network would not be interested in such a small fluctuation and does not want to get too many measurement reports triggered by such a small fluctuation. To provent this kind of unnecessarily frequent measurement report caused by small range of fluctuation, the parameter called 'Hysterisis' is introduced. The role of Hysterysis can be illustrated as below and hope this would make sense to you.
Before the handover, UE normally measure the cell power (signal quality) of the target cell and report it to the network, so that network can make a decision whether to allow UE to handover to the target cell or not. It is not a big issue to measure the signal quality of the target cell if the target cell is at the same frequency as the current cell (Intrafrequency measurement). But there would be an issue when the target cell is at a different frequency from the current cell (Interfrequency measurement). Just in terms of logical sense of view, the simplest solution for Interfrequency measurement, the simplest solution for this would be to implement two RF tranciever on UE. However, there are some practical problems with this kind of two tranciever solution. One of the problems is cost issue. It would require additional cost to implement the additional tranciever. The other problem would be the possible interference between the current frequency and target frequency especially when the current frequency and target frequency are close to each other.
So they come out with a special techique called "Measurement GAP". This is the same concept as "Compressed Mode" in UMTS. The idea of the Measurement GAP is to create a small gap during which no transmission and reception happens. since there is no signal transmission and reception during the gap, UE can switch to the target cell and perform the signal quality measurement and come back to the current cell. To make this work seamlessly, there should be a well established agreement between UE and Network about the gap definition (e.g, Starting Position of the Gap, Gap length, number of Gaps etc) and this agreement is established by MeasGapConfig IE of RRC Connection Reconfiguration message.
Measurement GAP for LTE and Legacy (UTRAN, GRAN etc)
If you see this part, RRC contents is small but you need to go through several steps as followsto fully understand the implementation of the measurement GAP. (The spreadsheet shown at the bottom is here. Let me know if you find any problem with this spreadsheet).
One of the complications about the measurement GAP would be how to schedule data transmission around the gap. Situation would be more complicated than you may think because we have to think about not only the data transmission itself, but also the scheduling grant and ACK/NACK transmission. One of possible scheduling example around measurement gap is as follows.
Measurement GAP for LTE and NR
As LTE evolves, we got increasing number of measurement gap definition and with the introduction of NR, this list got exploded as below.
Fundamental logic of the GAP setting is same as in LTE and Legacy case as explained above. Recap the procedure, it can be summarized as follows. i) Get the Gap Pattern ID from RRC MeasGapConfig and additional SMTC parameter from ii) Get the detailed Gap Setting Parameters for the Gap Pattern from 36.133 Table 8.1.2.1-1 iii) Determine Gap Subframe based on the condition described as below
Rules may sound simple ? It may sound simple, but you would not know how complicated it is before you really try it. Rehan has put a lot of his time and effort on this and completed the excel spreadsheet to show the gap settings for each subframe automatically according to the parameters you set. He kindly allowed me to share the spreadsheet for readers. Click here to get the file.
Followings a few examples from the spreadsheet. NOTE : You only need to set parameters highlighted in yellow. The values for grey cells are automatically derived from the vlues in yellow cells.
Example 1 > MGRP = 40ms, SSB Periodicity = 20ms
Example 2 > MGRP = 40ms, SSB Periodicity = 40ms
Basically overall RRC Structure is similar to LTE/Legacy case explained above, but there are a couple of additiona flags a shown and a lot of different gapoffset as shown below.
From 36.331 MeasConfig ::= SEQUENCE { .... measGapConfig MeasGapConfig OPTIONAL, ... [[ measGapConfigPerCC-List-r14 MeasGapConfigPerCC-List-r14 OPTIONAL, measGapSharingConfig-r14 MeasGapSharingConfig-r14 OPTIONAL ]], [[ fr1-Gap-r15 BOOLEAN OPTIONAL, -- Need ON mgta-r15 BOOLEAN OPTIONAL -- Need ON ]], [[ measGapConfigDensePRS-r15 MeasGapConfigDensePRS-r15 OPTIONAL, heightThreshRef-r15 CHOICE { release NULL, setup INTEGER (0..31) } OPTIONAL --Need ON ]] }
MeasGapConfig ::= CHOICE { release NULL, setup SEQUENCE { gapOffset CHOICE { gp0 INTEGER (0..39), gp1 INTEGER (0..79), ..., gp2-r14 INTEGER (0..39), gp3-r14 INTEGER (0..79), gp-ncsg0-r14 INTEGER (0..39), gp-ncsg1-r14 INTEGER (0..79), gp-ncsg2-r14 INTEGER (0..39), gp-ncsg3-r14 INTEGER (0..79), gp-nonUniform1-r14 INTEGER (0..1279), gp-nonUniform2-r14 INTEGER (0..2559), gp-nonUniform3-r14 INTEGER (0..5119), gp-nonUniform4-r14 INTEGER (0..10239), gp4-r15 INTEGER (0..19), gp5-r15 INTEGER (0..159), gp6-r15 INTEGER (0..19), gp7-r15 INTEGER (0..39), gp8-r15 INTEGER (0..79), gp9-r15 INTEGER (0..159), gp10-r15 INTEGER (0..19), gp11-r15 INTEGER (0..159) } } }
From 38.331 MeasObjectNR ::= SEQUENCE { }
SSB-MTC ::= SEQUENCE { periodicityAndOffset CHOICE { sf5 INTEGER (0..4), sf10 INTEGER (0..9), sf20 INTEGER (0..19), sf40 INTEGER (0..39), sf80 INTEGER (0..79), sf160 INTEGER (0..159) }, duration ENUMERATED { sf1, sf2, sf3, sf4, sf5 } }
SSB-MTC2 ::= SEQUENCE { pci-List SEQUENCE (SIZE (1..maxNrofPCIsPerSMTC)) OF PhysCellId OPTIONAL, periodicity ENUMERATED {sf5, sf10, sf20, sf40, sf80, spare3, spare2, spare1} }
< 36.133 v15.3 - Table 8.1.2.1-1: Gap Pattern Configurations supported by the UE >
< 36.133 v15.3 - Table 8.1.2.1-2: Gap Pattern Configurations for UE supporting low density burst gap pattens >
Layer 3 Filtering for Measurement Report
To be honest, I've never paid attention to this parameter before, but lately I heard an apisode of a serious field problem (too frequent handover failure) which was caused by a wrong implementation of this filter. It is the motivation for me to look into this parameter.
It is about the parameter for Layer 3 filtering for the measurement report value which is specified in rrcConnectionReconfiguration as specified below (in blue)
+-rrcConnectionReconfiguration-r8 ::= SEQUENCE [100000] +-measConfig ::= SEQUENCE [01010111111] OPTIONAL:Exist | +-measObjectToRemoveList ::= SEQUENCE OF OPTIONAL:Omit | +-measObjectToAddModList ::= SEQUENCE OF SIZE(1..maxObjectId[32]) [1] | | +-MeasObjectToAddMod ::= SEQUENCE | | +-measObjectId ::= INTEGER (1..maxObjectId[32]) [1] | | +-measObject ::= CHOICE [measObjectEUTRA] | +-reportConfigToRemoveList ::= SEQUENCE OF OPTIONAL:Omit | +-reportConfigToAddModList ::= SEQUENCE OF SIZE(1..maxReportConfigId[32]) [1] | | +-ReportConfigToAddMod ::= SEQUENCE | | +-reportConfigId ::= INTEGER (1..maxReportConfigId[32]) [1] | | +-reportConfig ::= CHOICE [reportConfigEUTRA] | | +-reportConfigEUTRA ::= SEQUENCE | | +-triggerType ::= CHOICE [event] | | | +-event ::= SEQUENCE | | | +-eventId ::= CHOICE [eventA3] | | | | +-eventA3 ::= SEQUENCE | | | | +-a3-Offset ::= INTEGER (-30..30) [0] | | | | +-reportOnLeave ::= BOOLEAN [FALSE] | | | +-hysteresis ::= INTEGER (0..30) [0] | | | +-timeToTrigger ::= ENUMERATED [ms640] | | +-triggerQuantity ::= ENUMERATED [rsrp] | | +-reportQuantity ::= ENUMERATED [both] | | +-maxReportCells ::= INTEGER (1..maxCellReport[8]) [1] | | +-reportInterval ::= ENUMERATED [ms1024] | | +-reportAmount ::= ENUMERATED [r1] | +-measIdToRemoveList ::= SEQUENCE OF OPTIONAL:Omit | +-measIdToAddModList ::= SEQUENCE OF SIZE(1..maxMeasId[32]) [1] OPTIONAL:Exist | | +-MeasIdToAddMod ::= SEQUENCE | | +-measId ::= INTEGER (1..maxMeasId[32]) [1] | | +-measObjectId ::= INTEGER (1..maxObjectId[32]) [1] | | +-reportConfigId ::= INTEGER (1..maxReportConfigId[32]) [1] | +-quantityConfig ::= SEQUENCE [1111] OPTIONAL:Exist | | +-quantityConfigEUTRA ::= SEQUENCE [11] OPTIONAL:Exist | | | +-filterCoefficientRSRP ::= ENUMERATED [fc0] OPTIONAL:Exist | | | +-filterCoefficientRSRQ ::= ENUMERATED [fc0] OPTIONAL:Exist
fc0 in filterCoefficientRSRP IE means "Do not apply Layer 3 filter and report the raw measured data". If filterCoefficientRSRP use a value other than fc0, it means "Apply Layer 3 filter with the specified the coefficient". The filter function and the meaning of each parameter is defined in 3GPP 36.331 5.5.3.2 Layer 3 filtering as follows.
There is a special type of Measurement Report. Normally Measurement Control/Report is for detecting the signal strength of the target cell, but CGI report is not for measuring the signal strength. It is to detect the Cell ID. It is not a simple cell ID, it is to measure CGI (Cell Global Identity) which uniquely identifies a cell in the whole world. For a ordinary measurement report, UE only have to switch its tuner to target cell and measure the signal strength and it does not have to decode any MIB, SIB of the target cell. It would take very short time to measure the signal strength. But it is different story in case of CGI. CGI is made up of PLMN + LAC + Cell ID. It means UE has to decode MIB/SIBs of the target cell. Decoding MIB/SIB is not a big issue if it is in idle mode, but the problem is that measurement control/report should happen in Connected Mode. Measurement GAP in LTE would not give enough time for UE to decode MIB/SIBs of the target cell. Then how can we give UE enough time to measure MIB/SIBs of target cell in connected mode. You can use DRX for this. Using DRX, you can give UE time long enough to measure MIB/SIBs of target cell. One think you have to be careful about DRX is that you have to make it sure that network should not send any data or UL Grant during the drx cycle. In case of measurement gap, measurement gap has high priority than data transmission/reception, but in DRX data transmission or handling UL grant has higher priority than DRX. It means if UE has any DL data or UL Grant during onTime of DRX cycle it does not goes into OFF period for a certain duration. If network keep sending data or UL grant during the DRX cycle (see DRX page for details), UE can never gets into OFF period meaning it cannot have time to switch to target cell for CGI detection. In this case, UE would still send Measurement Report but cgi-info field would be missing in the report.
Following is one example of RRC Connection Reconfiguration for CGI Report measurement control. See if my description above is properly reflecting the real message. For the details of this message, refer to following tables from 36.521-1.
Following is one example of Measurement Report that UE reported.
Example 1 > - Measuring RSRP, RSRQ for current Cell
Following is an example for RRC Connection Reconfiguration (Measurement) for the current cell (Serving Cell). You would notice that we don't need to configure anything about MeasurementGap since UE does not have to jump to other frequencies for the measurement.
+-c1 ::= CHOICE [rrcConnectionReconfiguration] +-rrcConnectionReconfiguration ::= SEQUENCE +-rrc-TransactionIdentifier ::= INTEGER (0..3) [0] +-criticalExtensions ::= CHOICE [c1] +-c1 ::= CHOICE [rrcConnectionReconfiguration-r8] +-rrcConnectionReconfiguration-r8 ::= SEQUENCE [100000] +-measConfig ::= SEQUENCE [01010110000] OPTIONAL:Exist | +-measObjectToRemoveList ::= SEQUENCE OF OPTIONAL:Omit | +-measObjectToAddModList ::= SEQUENCE OF SIZE(1..maxObjectId[32]) [1] OPTIONAL:Exist | | +-MeasObjectToAddMod ::= SEQUENCE | | +-measObjectId ::= INTEGER (1..maxObjectId[32]) [1] | | +-measObject ::= CHOICE [measObjectEUTRA] | | +-measObjectEUTRA ::= SEQUENCE [001000] | | +-carrierFreq ::= INTEGER (0..maxEARFCN[65535]) [2175] | | +-allowedMeasBandwidth ::= ENUMERATED [mbw50] | | +-presenceAntennaPort1 ::= BOOLEAN [FALSE] | | +-neighCellConfig ::= BIT STRING SIZE(2) [00] | | +-offsetFreq ::= ENUMERATED OPTIONAL:Omit | | +-cellsToRemoveList ::= SEQUENCE OF OPTIONAL:Omit | | +-cellsToAddModList ::= SEQUENCE OF SIZE(1..maxCellMeas[32]) [1] OPTIONAL:Exist | | | +-CellsToAddMod ::= SEQUENCE | | | +-cellIndex ::= INTEGER (1..maxCellMeas[32]) [1] | | | +-physCellId ::= INTEGER (0..503) [0] | | | +-cellIndividualOffset ::= ENUMERATED [dB-24] | | +-blackCellsToRemoveList ::= SEQUENCE OF OPTIONAL:Omit | | +-blackCellsToAddModList ::= SEQUENCE OF OPTIONAL:Omit | | +-cellForWhichToReportCGI ::= INTEGER OPTIONAL:Omit | +-reportConfigToRemoveList ::= SEQUENCE OF OPTIONAL:Omit | +-reportConfigToAddModList ::= SEQUENCE OF SIZE(1..maxReportConfigId[32]) [1] OPTIONAL:Exist | | +-ReportConfigToAddMod ::= SEQUENCE | | +-reportConfigId ::= INTEGER (1..maxReportConfigId[32]) [1] | | +-reportConfig ::= CHOICE [reportConfigEUTRA] | | +-reportConfigEUTRA ::= SEQUENCE | | +-triggerType ::= CHOICE [periodical] | | | +-periodical ::= SEQUENCE | | | +-purpose ::= ENUMERATED [reportStrongestCells] | | +-triggerQuantity ::= ENUMERATED [rsrp] | | +-reportQuantity ::= ENUMERATED [both] | | +-maxReportCells ::= INTEGER (1..maxCellReport[8]) [1] | | +-reportInterval ::= ENUMERATED [ms480] | | +-reportAmount ::= ENUMERATED [infinity] | +-measIdToRemoveList ::= SEQUENCE OF OPTIONAL:Omit | +-measIdToAddModList ::= SEQUENCE OF SIZE(1..maxMeasId[32]) [1] OPTIONAL:Exist | | +-MeasIdToAddMod ::= SEQUENCE | | +-measId ::= INTEGER (1..maxMeasId[32]) [1] | | +-measObjectId ::= INTEGER (1..maxObjectId[32]) [1] | | +-reportConfigId ::= INTEGER (1..maxReportConfigId[32]) [1] | +-quantityConfig ::= SEQUENCE [1000] OPTIONAL:Exist | | +-quantityConfigEUTRA ::= SEQUENCE [11] OPTIONAL:Exist | | | +-filterCoefficientRSRP ::= ENUMERATED [fc4] OPTIONAL:Exist | | | +-filterCoefficientRSRQ ::= ENUMERATED [fc4] OPTIONAL:Exist | | +-quantityConfigUTRA ::= SEQUENCE OPTIONAL:Omit | | +-quantityConfigGERAN ::= SEQUENCE OPTIONAL:Omit | | +-quantityConfigCDMA2000 ::= SEQUENCE OPTIONAL:Omit | +-measGapConfig ::= CHOICE OPTIONAL:Omit | +-s-Measure ::= INTEGER OPTIONAL:Omit | +-preRegistrationInfoHRPD ::= SEQUENCE OPTIONAL:Omit | +-speedStatePars ::= CHOICE OPTIONAL:Omit +-mobilityControlInfo ::= SEQUENCE OPTIONAL:Omit +-dedicatedInfoNASList ::= SEQUENCE OF OPTIONAL:Omit +-radioResourceConfigDedicated ::= SEQUENCE OPTIONAL:Omit +-securityConfigHO ::= SEQUENCE OPTIONAL:Omit +-nonCriticalExtension ::= SEQUENCE OPTIONAL:Omit
An example of Measurement Report for the measurement configuration specified above is as follows.
+-c1 ::= CHOICE [measurementReport] +-measurementReport ::= SEQUENCE +-criticalExtensions ::= CHOICE [c1] +-c1 ::= CHOICE [measurementReport-r8] +-measurementReport-r8 ::= SEQUENCE [0] +-measResults ::= SEQUENCE [0] | +-measId ::= INTEGER (1..maxMeasId[32]) [1] | +-measResultServCell ::= SEQUENCE | | +-rsrpResult ::= INTEGER (0..97) [52] | | +-rsrqResult ::= INTEGER (0..34) [18] | +-measResultNeighCells ::= CHOICE OPTIONAL:Omit +-nonCriticalExtension ::= SEQUENCE OPTIONAL:Omit
Example 2 > - Event Based Measurement : A1, A2, A3
Following is an example log captured in live network with Azenqos tool . In this example, network configures various measurement objects simultaneously with multiple different events. You wouldn't see the event based measurement report in this example (since UE didn't meet the condition for those events), but you will see the good examples how multiple different events are defined in a single rrc message and how UE report those multiple measurement. Usually measurements configuration in live network is much more complicated than those settings in the test equipment. So this can be a very practical examples for you.
DL-DCCH-Message ::= { message: c1: rrcConnectionReconfiguration: RRCConnectionReconfiguration ::= { rrc-TransactionIdentifier: 3 criticalExtensions: c1: rrcConnectionReconfiguration-r8: RRCConnectionReconfiguration-r8-IEs ::= { measConfig: MeasConfig ::= { measObjectToAddModList: MeasObjectToAddModList ::= { MeasObjectToAddMod ::= { measObjectId: 1 measObject: measObjectEUTRA: MeasObjectEUTRA ::= { carrierFreq: 1300 allowedMeasBandwidth: 3 (mbw50) presenceAntennaPort1: FALSE neighCellConfig: '01' offsetFreq: 15 (dB0) cellsToAddModList: CellsToAddModList ::= { CellsToAddMod ::= { cellIndex: 1 physCellId: 290 cellIndividualOffset: 15 (dB0) } } } } } reportConfigToAddModList: ReportConfigToAddModList ::= { ReportConfigToAddMod ::= { reportConfigId: 1 reportConfig: reportConfigEUTRA: ReportConfigEUTRA ::= { triggerType: event: event ::= { eventId: eventA3: eventA3 ::= { a3-Offset: 2 reportOnLeave: FALSE } hysteresis: 2 timeToTrigger: 8 (ms320) } triggerQuantity: 0 (rsrp) reportQuantity: 0 (sameAsTriggerQuantity) maxReportCells: 4 reportInterval: 1 (ms240) reportAmount: 7 (infinity) reportconfigeutra-ext1: reportconfigeutra-ext1 ::= { reportAddNeighMeas-r10: 0 (setup) } } } ReportConfigToAddMod ::= { reportConfigId: 2 reportConfig: reportConfigEUTRA: ReportConfigEUTRA ::= { triggerType: event: event ::= { eventId: eventA3: eventA3 ::= { a3-Offset: -20 reportOnLeave: TRUE } hysteresis: 4 timeToTrigger: 11 (ms640) } triggerQuantity: 0 (rsrp) reportQuantity: 1 (both) maxReportCells: 8 reportInterval: 6 (ms5120) reportAmount: 7 (infinity) reportconfigeutra-ext1: reportconfigeutra-ext1 ::= { reportAddNeighMeas-r10: 0 (setup) } } } ReportConfigToAddMod ::= { reportConfigId: 3 reportConfig: reportConfigEUTRA: ReportConfigEUTRA ::= { triggerType: event: event ::= { eventId: eventA1: eventA1 ::= { a1-Threshold: threshold-RSRP: 37 } hysteresis: 2 timeToTrigger: 11 (ms640) } triggerQuantity: 0 (rsrp) reportQuantity: 1 (both) maxReportCells: 1 reportInterval: 2 (ms480) reportAmount: 0 (r1) } } ReportConfigToAddMod ::= { reportConfigId: 4 reportConfig: reportConfigEUTRA: ReportConfigEUTRA ::= { triggerType: event: event ::= { eventId: eventA2: eventA2 ::= { a2-Threshold: threshold-RSRP: 33 } hysteresis: 2 timeToTrigger: 11 (ms640) } triggerQuantity: 0 (rsrp) reportQuantity: 1 (both) maxReportCells: 1 reportInterval: 2 (ms480) reportAmount: 0 (r1) } } ReportConfigToAddMod ::= { reportConfigId: 5 reportConfig: reportConfigEUTRA: ReportConfigEUTRA ::= { triggerType: event: event ::= { eventId: eventA1: eventA1 ::= { a1-Threshold: threshold-RSRP: 45 } hysteresis: 2 timeToTrigger: 11 (ms640) } triggerQuantity: 0 (rsrp) reportQuantity: 1 (both) maxReportCells: 1 reportInterval: 2 (ms480) reportAmount: 0 (r1) } } ReportConfigToAddMod ::= { reportConfigId: 6 reportConfig: reportConfigEUTRA: ReportConfigEUTRA ::= { triggerType: event: event ::= { eventId: eventA2: eventA2 ::= { a2-Threshold: threshold-RSRP: 41 } hysteresis: 2 timeToTrigger: 11 (ms640) } triggerQuantity: 0 (rsrp) reportQuantity: 1 (both) maxReportCells: 1 reportInterval: 2 (ms480) reportAmount: 0 (r1) } } } measIdToAddModList: MeasIdToAddModList ::= { MeasIdToAddMod ::= { measId: 1 measObjectId: 1 reportConfigId: 1 } MeasIdToAddMod ::= { measId: 2 measObjectId: 1 reportConfigId: 2 } MeasIdToAddMod ::= { measId: 3 measObjectId: 1 reportConfigId: 3 } MeasIdToAddMod ::= { measId: 4 measObjectId: 1 reportConfigId: 4 } MeasIdToAddMod ::= { measId: 5 measObjectId: 1 reportConfigId: 5 } MeasIdToAddMod ::= { measId: 6 measObjectId: 1 reportConfigId: 6 } } quantityConfig: QuantityConfig ::= { quantityConfigEUTRA: QuantityConfigEUTRA ::= { filterCoefficientRSRP: 6 (fc6) filterCoefficientRSRQ: 6 (fc6) } } s-Measure: 0 speedStatePars: release: <present> } } } }
Now UE reports multiple measurement reports for each measurement ID.
UL-DCCH-Message ::= { message: c1: measurementReport: MeasurementReport ::= { criticalExtensions: c1: measurementReport-r8: MeasurementReport-r8-IEs ::= { measResults: MeasResults ::= { measId: 2 measResultPCell: measResultPCell ::= { rsrpResult: 21 rsrqResult: 10 } measResultNeighCells: measResultListEUTRA: MeasResultListEUTRA ::= { MeasResultEUTRA ::= { physCellId: 284 measResult: measResult ::= { rsrpResult: 20 rsrqResult: 17 } } } measresults-ext0: measresults-ext0 ::= { } measresults-ext1: measresults-ext1 ::= { measResultServFreqList-r10: MeasResultServFreqList-r10 ::= { MeasResultServFreq-r10 ::= { servFreqId-r10: 1 measResultSCell-r10: measResultSCell-r10 ::= { rsrpResultSCell-r10: 29 rsrqResultSCell-r10: 23 } } } } } } } }
UL-DCCH-Message ::= { message: c1: measurementReport: MeasurementReport ::= { criticalExtensions: c1: measurementReport-r8: MeasurementReport-r8-IEs ::= { measResults: MeasResults ::= { measId: 4 measResultPCell: measResultPCell ::= { rsrpResult: 21 rsrqResult: 10 } measresults-ext0: measresults-ext0 ::= { } measresults-ext1: measresults-ext1 ::= { measResultServFreqList-r10: MeasResultServFreqList-r10 ::= { MeasResultServFreq-r10 ::= { servFreqId-r10: 1 measResultSCell-r10: measResultSCell-r10 ::= { rsrpResultSCell-r10: 29 rsrqResultSCell-r10: 23 } } } } } } } }
UL-DCCH-Message ::= { message: c1: measurementReport: MeasurementReport ::= { criticalExtensions: c1: measurementReport-r8: MeasurementReport-r8-IEs ::= { measResults: MeasResults ::= { measId: 6 measResultPCell: measResultPCell ::= { rsrpResult: 21 rsrqResult: 10 } measresults-ext0: measresults-ext0 ::= { } measresults-ext1: measresults-ext1 ::= { measResultServFreqList-r10: MeasResultServFreqList-r10 ::= { MeasResultServFreq-r10 ::= { servFreqId-r10: 1 measResultSCell-r10: measResultSCell-r10 ::= { rsrpResultSCell-r10: 29 rsrqResultSCell-r10: 23 } } } } } } } }
Example 3 > - Event Based Measurement : A5
Following is an example log captured in live network with Azenqos tool . In this example, network configures various measurement objects simultaneously with multiple different events. You wouldn't see the event based measurement report in this example (since UE didn't meet the condition for those events), but you will see the good examples how multiple different events are defined in a single rrc message and how UE report those multiple measurement. Usually measurements configuration in live network is much more complicated than those settings in the test equipment. So this can be a very practical examples for you.
DL-DCCH-Message ::= { message: c1: rrcConnectionReconfiguration: RRCConnectionReconfiguration ::= { rrc-TransactionIdentifier: 0 criticalExtensions: c1: rrcConnectionReconfiguration-r8: RRCConnectionReconfiguration-r8-IEs ::= { measConfig: MeasConfig ::= { measObjectToAddModList: MeasObjectToAddModList ::= { MeasObjectToAddMod ::= { measObjectId: 2 measObject: measObjectEUTRA: MeasObjectEUTRA ::= { carrierFreq: 251 allowedMeasBandwidth: 3 (mbw50) presenceAntennaPort1: FALSE neighCellConfig: '01' offsetFreq: 15 (dB0) measobjecteutra-ext0: measobjecteutra-ext0 ::= { measCycleSCell-r10: 2 (sf320) } } } MeasObjectToAddMod ::= { measObjectId: 3 measObject: measObjectEUTRA: MeasObjectEUTRA ::= { carrierFreq: 1275 allowedMeasBandwidth: 4 (mbw75) presenceAntennaPort1: FALSE neighCellConfig: '01' offsetFreq: 15 (dB0) } } } reportConfigToAddModList: ReportConfigToAddModList ::= { ReportConfigToAddMod ::= { reportConfigId: 7 reportConfig: reportConfigEUTRA: ReportConfigEUTRA ::= { triggerType: event: event ::= { eventId: eventA5: eventA5 ::= { a5-Threshold1: threshold-RSRP: 31 a5-Threshold2: threshold-RSRP: 37 } hysteresis: 2 timeToTrigger: 11 (ms640) } triggerQuantity: 0 (rsrp) reportQuantity: 0 (sameAsTriggerQuantity) maxReportCells: 4 reportInterval: 1 (ms240) reportAmount: 7 (infinity) reportconfigeutra-ext1: reportconfigeutra-ext1 ::= { reportAddNeighMeas-r10: 0 (setup) } } } ReportConfigToAddMod ::= { reportConfigId: 8 reportConfig: reportConfigEUTRA: ReportConfigEUTRA ::= { triggerType: event: event ::= { eventId: eventA3: eventA3 ::= { a3-Offset: 2 reportOnLeave: FALSE } hysteresis: 2 timeToTrigger: 8 (ms320) } triggerQuantity: 0 (rsrp) reportQuantity: 0 (sameAsTriggerQuantity) maxReportCells: 4 reportInterval: 1 (ms240) reportAmount: 7 (infinity) reportconfigeutra-ext1: reportconfigeutra-ext1 ::= { reportAddNeighMeas-r10: 0 (setup) } } } } measIdToAddModList: MeasIdToAddModList ::= { MeasIdToAddMod ::= { measId: 7 measObjectId: 2 reportConfigId: 7 } MeasIdToAddMod ::= { measId: 8 measObjectId: 3 reportConfigId: 8 } } measGapConfig: setup: setup ::= { gapOffset: gp0: 32 } } } } }
Followings are the measurement report from UE based on the configuration shown above. Here again, there is no report about Event 5 or 3 configured above sinec UE didn't hit the condition for those events in this test.
UL-DCCH-Message ::= { message: c1: measurementReport: MeasurementReport ::= { criticalExtensions: c1: measurementReport-r8: MeasurementReport-r8-IEs ::= { measResults: MeasResults ::= { measId: 2 measResultPCell: measResultPCell ::= { rsrpResult: 19 rsrqResult: 6 } measResultNeighCells: measResultListEUTRA: MeasResultListEUTRA ::= { MeasResultEUTRA ::= { physCellId: 284 measResult: measResult ::= { rsrpResult: 20 rsrqResult: 17 } } MeasResultEUTRA ::= { physCellId: 288 measResult: measResult ::= { rsrpResult: 17 rsrqResult: 8 } } } measresults-ext0: measresults-ext0 ::= { } measresults-ext1: measresults-ext1 ::= { measResultServFreqList-r10: MeasResultServFreqList-r10 ::= { MeasResultServFreq-r10 ::= { servFreqId-r10: 1 measResultSCell-r10: measResultSCell-r10 ::= { rsrpResultSCell-r10: 27 rsrqResultSCell-r10: 20 } measResultBestNeighCell-r10: measResultBestNeighCell-r10 ::= { physCellId-r10: 284 rsrpResultNCell-r10: 26 rsrqResultNCell-r10: 19 } } } } } } } }
Frequent Issues Regarding Measurement Report
There can be many issues that are frequently observed in the field and followings are some examples of those issues.
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