LTE RRC Connection Reconfiguration event A2 threshold two values purpose

[kentck86]

Hi guys,

Wonder if anyone know why the content of RRC Connection reconfiguration message for LTE content 2 event A2 for EUTRAN does it mean one setting for interfrequency event and another one maybe for redirection event?

{
reportConfigId 3,
reportConfig reportConfigEUTRA : {
triggerType event : {
eventId eventA2 : {
a2-Threshold threshold-RSRP : 0
},
hysteresis 0,
timeToTrigger ms256
},
triggerQuantity rsrp,
reportQuantity sameAsTriggerQuantity,
maxReportCells 8,
reportInterval min60,
reportAmount r1
}
},
{
reportConfigId 4,
reportConfig reportConfigEUTRA : {
triggerType event : {
eventId eventA2 : {
a2-Threshold threshold-RSRP : 30
},
hysteresis 0,
timeToTrigger ms480
},
triggerQuantity rsrp,
reportQuantity sameAsTriggerQuantity,
maxReportCells 8,
reportInterval min60,
reportAmount r1
}
}

[agenov]

depending on mobility algorithms that you have enabled but most probably in your case one of the event is for InterFreq measurements and the other one for InterRAT . In general , event A2 is used for entering compressed mode and measure another LTE layer or Irat.
BR
Alex

[auto_art]

this is just an event that will be triggered for the specific measurement config.
reportConfigId 3, is triggering when rsrp is worse than -140+hys means it wont happen in any normal scenario. e.g. -140 means there is not connection between UE and BS so no where to send the measurement report.

reportConfigId 4, is triggering at -110+hys , so when rsrp for specific measure config hits this level it will trigger the measurement report.

there can be more than one report config per it depends on the vendor algo.

"E-UTRAN may configure multiple instances of the same event e.g. by configuring two reportingconfigurations with different thresholds."

read section 5.5 specs.
https://www.etsi.org/deliver/etsi_ts/136300_136399/136331/09.16.00_60/ts_136331v091600p.pdf



Also A2 has nothing to do with inter or intra freq. it just measure current serving cell against a threshold.

[kentck86]

Thank you for comment guys.
I founded out my case the first event A2 is threshold setting for Redirection to other RAT, the second event A2 threshold is for Interfrequency.