UE测量上报RSRP之后，由网络侧决定UE是否切换。
做这个决定的过程就是切换算法了，主要涉及到两个方面：（1）测量的量（2）测量方法。
如果简单地通过某个时刻变量的大小就决定是否切换，似乎不是一个符合实际的办法。因为实际上，网络和信号质量变化很快，也不稳定，所有需要测量不同的量和连续性来判断是否切换。
在RRC消息中，关于测量配置的关键字有：
在38.331/36.331中第五章有介绍测量事件的类型。
那么事件的触发在于测量的信号是否超过了某一门限。
有的时候网络信号有波动性，但是网络并不是特别care这样的小范围的波动性，只有累计到达一定程度的时候才会引起网络的主意，所有引用hysterisis来解决这一问题。
一个例子
基站配置给UE的测量RRC消息如下：
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>
}
}
}
}
UE是这样上报测量结果的，因为有些测量条件没有满足，所有UE没有上报，如下：
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
}
}
}
}
}
}
}
}