LTE measurement events MEASUREMENT REPORT: EVENTS A1, A2, A3, A4, A5 & B2 1 Measurement Report: LTE Events 0 PERIODICAL - Periodical reporting 1 EVENT_ A1 -Serving cell becomes better than absolute threshold 2 EVENT_ A2 -Serving cell becomes worse than absolute threshold 3 EVENT_ A3 -Neighbor cell becomes amount of offset better than serving 4 EVENT_ A4 -Neighbor cell becomes better than absolute threshold 5 EVENT_ A5 -Serving cell becomes worse than absolute threshold1 and Neighbor cell becomes better than another absolute threshold2 Measurement Report: LTE Events (IRAT) 0 PERIODICAL -Periodical reporting 1 EVENT_ B1 -IRAT neighbor better than threshold 2 EVENT_ B2 -Serving becomes worse than threshold1 and IRAT neighbor becomes better then threshold2 Event A1 • The redirection to another frequency may be cancelled by Event A1 “Good Coverage” • An Event A1 Good Coverage measurement report arrives from the UE • Event A1:Serving becomes Better than absolute Threshold • This Event is used in IRAT Mobility Leliwa Technical Bulletin LTE measurement events Event A1 Serving becomes better than threshold Hysteresis a1-Threshold reportAmount reportQuantity time triggerType=event eventId=eventA1 4 A1:Serving Becomes Better than absolute threshold Event A2 • Having two measurement thresholds for poor coverage evaluation allows for the use of different hysteresis and timer values for the different threshold values • The redirection to another frequency triggered by Event A2 “Bad Coverage” • Event A2:Serving becomes worse than absolute Threshold A2:Serving becomes worse than absolute threshold (mal) Event A3 • The Intra-LTE Handover feature configures Event A3 as defined in 3GPP TS36.331. • The Event A3 implies that one or several neighbor cells become better then the serving cell also when some offset and hysteresis values are taken into account. • “Neighbor becomes offset better than serving” • Event A3:Neighbor becomes amount offset better than serving. Leliwa Technical Bulletin LTE measurement events Event A3 Neighbour becomes offset better than serving Hysteresis offset s-cell n-cell reportAmount reportQuantity time triggerType=event eventId=eventA3 reportOnLeave timeToTrigger reportInterval Offset = a3-offset + offsetFreqs + cellIndividualOffsets - offsetFreqn - cellIndividualOffsetn 6 A3:Neighbor becomes offset better than serving UE evaluating entry to Event A3 • Equation 1 Formula for Entering EventA3 Mn+cellIndividualOffsetEUtran-hysteresisA3>Ms+a3Offset • Equation 2 Formula for Leaving EventA3 Mn+cellIndividualOffsetEUtran+hysteresisA3<Ms+a3Offset where: Mn = Measured value of the neighboring cell (either RSRP or RSRQ) Ms = Measured value of the serving cell (either RSRP or RSRQ) Event A4 • Neighbor cell becomes better than absolute threshold Leliwa Technical Bulletin LTE measurement events Event A4 Neighbour becomes offset better than threshold Hysteresis offset reportAmount a4-Threshold reportQuantity time reportOnLeave triggerType=event eventId=eventA4 timeToTrigger reportInterval Offset = offsetFreqn + cellIndividualOffsetn 7 Leliwa Technical Bulletin LTE measurement events Event B2 Serving becomes worse than threshold1 and inter RAT neighbour becomes better than threshold2) condition 2 fulfilled condition 1 fulfilled b2-Threshold2UTRA/GERAN OffsetFreq Hysteresis s-cell b2-Threshold1 reportAmount Hysteresis reportQuantity triggerType=event eventId=eventB2 n-cell time reportOnLeave timeToTrigger reportInterval 10 Event A5 • Is used by Inter FREQUENCY Handover in order to find a frequency to redirect to or a cell to make handover to. • A5:Serving worse than threshold 1 AND Neighbor better than threshold 2 Leliwa Technical Bulletin LTE measurement events Event A5 Serving becomes worse than thr.1 and neighbour becomes better than thr.2 condition 2 fulfilled condition 1 fulfilled a5-Threshold2 offset Hysteresis s-cell a5-Threshold1 reportAmount Hysteresis reportQuantity n-cell time reportOnLeave triggerType=event timeToTrigger reportInterval eventId=eventA5 offset = offsetFreqn + cellIndividualOffsetn 8 A5:Serving worse than threshold 1 AND Neighbor better than threshold 2 Event B1 • IRAT neighbor better than threshold Leliwa Technical Bulletin LTE measurement events Event B1 Inter RAT neighbour becomes better than threshold Hysteresis OffsetFreq reportAmount a1-ThresholdUTRA/GERAN reportQuantity time reportOnLeave triggerType=event eventId=eventB1 timeToTrigger reportInterval 9 Event B2 • Event B2 is used by IRAT Coverage Triggered Session Continuity in order to decide which type of release (blind or not) will be performed. B2:Serving worse then threshold 1 AND IRAT Neighbor better than threshold 2 Leliwa Technical Bulletin LTE measurement events Speed dependant scaling of measurement parameters time timeToTrigger timeToTriger:=timeToTrigger*sf-Medium (medium-mobility detected) timeToTriger:=timeToTrigger*sf-High (high-mobility detected) 11 Leliwa Technical Bulletin LTE measurement events Acronyms and Abbreviations AKA CCO CDMA DCCH DL EGPRS GERAN HO MME NAS PCCH PLMN PSI RAT RLC RNTI RRC RSCP RSRP RXLEV TMSI UE UL UTRAN Authentication and Key Agreement Cell Change Order Code Division Multiple Access Dedicated Control Channel Downlink Enhanced General Packet Radio Service GSM/EDGE Radio Access Network Handover Mobility Management Entity Non-access Stratum Signalling Paging Control Channel Public Land Mobile Network Public Service Identity Radio Access Technology Radio Link Control Radio Network Temporary Identifier Radio Resource Control Received Signal Code Power Reference Signal Received Power Received Signal Level Temporary Mobile Subscriber Identity Number User Equipment Uplink UMTS Terrestrial Radio Access Network 12 Leliwa Technical Bulletin LTE measurement events References This section contains the locations of various specifications, document references and useful information where you can learn more about this subject. [1] 3GPP TS 36.331 Evolved Universal Terrestrial Radio Access (E-UTRA); Radio Resource Control (RRC); Protocol specification 13
