Section 1.4 SIB3

• Introduction
• SIB3 Information element
• SIB3 message
• References

Introduction

• SIB3包含了用于同频, 异频, 异系统间小区重选的基本共用信息
• 除临区相关信息之外的同频小区重选信息

SIB3 Information element

SystemInformationBlockType3 ::= SEQUENCE {
   cellReselectionInfoCommon SEQUENCE {
      q-Hyst ENUMERATED {
         dB0, dB1, dB2, dB3, dB4, dB5, dB6, dB8, dB10,
         dB12, dB14, dB16, dB18, dB20, dB22, dB24},
      speedStateReselectionPars SEQUENCE {
         mobilityStateParameters MobilityStateParameters,
         q-HystSF SEQUENCE {
            sf-Medium ENUMERATED {
               dB-6, dB-4, dB-2, dB0},
            sf-High ENUMERATED {
               dB-6, dB-4, dB-2, dB0}
            }
         } OPTIONAL -- Need OP
      },
   cellReselectionServingFreqInfo SEQUENCE {
      s-NonIntraSearch ReselectionThreshold OPTIONAL, -- Need OP
      threshServingLow ReselectionThreshold,
      cellReselectionPriority CellReselectionPriority
      },
   intraFreqCellReselectionInfo SEQUENCE {
      q-RxLevMin Q-RxLevMin,
      p-Max P-Max OPTIONAL, -- Need OP
      s-IntraSearch ReselectionThreshold OPTIONAL, -- Need OP
      allowedMeasBandwidth AllowedMeasBandwidth OPTIONAL, -- Need OP
      presenceAntennaPort1 PresenceAntennaPort1,
      neighCellConfig NeighCellConfig,
      t-ReselectionEUTRA T-Reselection,
      t-ReselectionEUTRA-SF SpeedStateScaleFactors OPTIONAL -- Need OP
      },
   ...,
   lateNonCriticalExtension OCTET STRING (CONTAINING SystemInformationBlockType3-v10j0-IEs) OPTIONAL,
   [[ s-IntraSearch-v920 SEQUENCE {
      s-IntraSearchP-r9 ReselectionThreshold,
      s-IntraSearchQ-r9 ReselectionThresholdQ-r9
      } OPTIONAL, -- Need OP
   s-NonIntraSearch-v920 SEQUENCE {
      s-NonIntraSearchP-r9 ReselectionThreshold,
      s-NonIntraSearchQ-r9 ReselectionThresholdQ-r9
      } OPTIONAL, -- Need OP
   q-QualMin-r9 Q-QualMin-r9 OPTIONAL, -- Need OP
   threshServingLowQ-r9 ReselectionThresholdQ-r9 OPTIONAL -- Need OP
   ]],
   [[ q-QualMinWB-r11 Q-QualMin-r9 OPTIONAL -- Cond WB-RSRQ
   ]],
   [[ q-QualMinRSRQ-OnAllSymbols-r12 Q-QualMin-r9 OPTIONAL -- Cond RSRQ
   ]],
   [[ cellReselectionServingFreqInfo-v1310 CellReselectionServingFreqInfo-v1310 OPTIONAL, -- Need OP
   redistributionServingInfo-r13 RedistributionServingInfo-r13 OPTIONAL, --Need OR
   cellSelectionInfoCE-r13 CellSelectionInfoCE-r13 OPTIONAL, -- Need OP
   t-ReselectionEUTRA-CE-r13 T-ReselectionEUTRA-CE-r13 OPTIONAL -- Need OP
   ]]
}

SIB3 message

.SIB3

MS1
System Information Block 3  

Time : 17:45:36.299
q-Hyst : dB3
s-NonIntraSearch : 22 
threshServingLow : 15
cellReselectionPriority : 7
q-RxLevMin : -60
p-Max : 23
s-IntraSearch : 19
allowedMeasBandwidth : mbw100
presenceAntennaPort1 : False
neighCellConfig
  Binary string (Bin) : 01
    [0 ] : 0
    [1 ] : 1
t-ReselectionEUTRA : 1

• q-Hyst 小区重选迟滞. 用于作用在(在服务小区测量RSRP值上加上该值)服务小区后作为重选判决依据
• s-NonIntraSearch 异频搜索门限. 低于22dB开启.用于进行异频小区重选时, 判断是否进行异频小区重选测量的门限参数. 在异频重选的情况下, 如果相邻小区的优先级高于服务小区, UE需要进行异频小区重选测量. 另外, 如果此Snonintrasearch参数没有在系统消息内广播, UE也需要进行异频小区的重选测量. 否则UE可以选择只有当服务小区的S值小于等于Snonintrasearch时, 才进行异频小区的重选测量;
• threshServingLow 由服务频率向低优先级重选时门限. 实际值=7*2=14dB
• cellReselectionPriority 小区重选优先级.定义了服务频率在异频小区重选的优先级,异频的小区切换基于优先级值的大小, UE通常总是会尝试驻留在优先级高的小区. [0-7] where 0 means: lowest priority.
• q-RxLevMin 小区要求的最小接收功率RSRP值[dBm], 即当UE测量小区RSRP低于该值时, UE是无法在该小区驻留的. 实际的值为: Q~rxlevmin~ = IE value * 2, -60为-120dBm
• p-Max 同频临小区上行传输功率最大值. 如果缺省, UE采用自己的传输功率最大值.
• s-IntraSearch 用于进行同频小区重选时, 判断是否进行同频小区重选的门限参数. 当LTE服务小区的S值小于等于s-IntraSearch时, 就要执行同频小区重选测量; 另外如果此s-IntraSearch参数没有在系统消息内广播, 也要执行同频小区重选测量. 除此之外, UE可以选择不进行测量.
• allowedMeasBandwidth [later]
• presenceAntennaPort1 [later]
• neighCellConfig 用于提供临小区MBSFN和上下行配比信息. 00: 不是所有邻区均和当前服务小区有相同的MBSFN子帧配置. 10: 所有邻区均和当前服务小区有相同的MBSFN子帧配置. 01: 所有邻区均没有MBSFN子帧配置. 11: 相对于服务小区的UL/DL配置, 邻区中存在不同的UL/DL配置. 对于TDD, 00, 10, 01只用于服务小区和邻区的UL/DL配置相同情况.
• t-ReselectionEUTRA EUTRA小区重选定时器,定义了小区选择的时间间隔 1s

References

1. TS 36.331 6.3.1 SystemInformationBlockType3