eMTC网络系统广播消息研究
背景
LTE对于小区的公共配置参数通过系统广播消息发送给终端。终端在完成搜网和同步以后，下一步就是接收和解析系统广播消息。
系统广播消息分为MIB和SIB。MIB在BCH上发送，SIB在DL-SCH上发送。
eMTC是3GPP R13中为了增强对LTE - M的支持而引入的新的技术，也成为LTE CAT-M1。
国内目前没有eMTC商用网络，使用eMTC终端接入微戎WR100s测试系统，可以抓取信令消息进行分析。
MIB消息
MIB消息中以空闲的5bit携带schedulingInfoSIB1-BR-r13指示该小区是支持eMTC。以下是MIB消息的解析：
dl-Bandwidth: n50 (3)
phich-Config
phich-Duration: normal (0)
phich-Resource: one (2)
systemFrameNumber: 2e [bit length 8, 0010 1110 decimal value 46]
schedulingInfoSIB1-BR-r13: 16 PDSCH repetitions - TBS 208 bits (3)
spare: 00 [bit length 5, 3 LSB pad bits, 0000 0... decimal value 0]
SIB1消息
eMTC相关的配置参数主要是 bandwidthReducedAccessRelatedInfo-r13
c1: systemInformationBlockType1 (1)
systemInformationBlockType1
cellAccessRelatedInfo
plmn-IdentityList: 1 item
Item 0
PLMN-IdentityInfo
plmn-Identity
mcc: 3 items
Item 0
MCC-MNC-Digit: 0
Item 1
MCC-MNC-Digit: 0
Item 2
MCC-MNC-Digit: 1
mnc: 2 items
Item 0
MCC-MNC-Digit: 0
Item 1
MCC-MNC-Digit: 1
cellReservedForOperatorUse: notReserved (1)
trackingAreaCode: 0001 [bit length 16, 0000 0000 0000 0001 decimal value 1]
cellIdentity: 1a2e0010 [bit length 28, 4 LSB pad bits, 0001 1010 0010 1110 0000 0000 0001 .... decimal value 27451393]
cellBarred: notBarred (1)
intraFreqReselection: allowed (0)
.... ..0. csg-Indication: False
cellSelectionInfo
q-RxLevMin: -130dBm (-65)
p-Max: 23dBm
freqBandIndicator: 13
schedulingInfoList: 1 item
Item 0
SchedulingInfo
si-Periodicity: rf8 (0)
sib-MappingInfo: 0 items
si-WindowLength: ms40 (6)
systemInfoValueTag: 8
nonCriticalExtension
nonCriticalExtension
nonCriticalExtension
nonCriticalExtension
cellAccessRelatedInfo-v1250
nonCriticalExtension
bandwidthReducedAccessRelatedInfo-r13
si-WindowLength-BR-r13: ms80 (3)
si-RepetitionPattern-r13: everyRF (0)
schedulingInfoList-BR-r13: 1 item
Item 0
SchedulingInfo-BR-r13
si-Narrowband-r13: 2
si-TBS-r13: b408 (4)
startSymbolBR-r13: 3
si-HoppingConfigCommon-r13: off (1)
SIB2消息
SIB2消息中最关键的是mpdcch的参数配置，这是eMTC引入的新的信道。
c1: systemInformation (0)
systemInformation
criticalExtensions: systemInformation-r8 (0)
systemInformation-r8
sib-TypeAndInfo: 1 item
Item 0
sib-TypeAndInfo item: sib2 (0)
sib2
radioResourceConfigCommon
rach-ConfigCommon
preambleInfo
numberOfRA-Preambles: n52 (12)
powerRampingParameters
powerRampingStep: dB2 (1)
preambleInitialReceivedTargetPower: dBm-104 (8)
ra-SupervisionInfo
preambleTransMax: n10 (6)
ra-ResponseWindowSize: sf10 (7)
mac-ContentionResolutionTimer: sf40 (4)
maxHARQ-Msg3Tx: 5
preambleTransMax-CE-r13: n200 (10)
rach-CE-LevelInfoList-r13: 1 item
Item 0
RACH-CE-LevelInfo-r13
preambleMappingInfo-r13
firstPreamble-r13: 0
lastPreamble-r13: 52
ra-ResponseWindowSize-r13: sf50 (1)
mac-ContentionResolutionTimer-r13: sf100 (1)
rar-HoppingConfig-r13: off (1)
bcch-Config
modificationPeriodCoeff: n4 (1)
pcch-Config
defaultPagingCycle: rf128 (2)
nB: oneT (2)
prach-Config
rootSequenceIndex: 98
prach-ConfigInfo
prach-ConfigIndex: 3
..0. .... highSpeedFlag: False
zeroCorrelationZoneConfig: 12
prach-FreqOffset: 2
pdsch-ConfigCommon
referenceSignalPower: -8dBm
p-b: 1
pusch-ConfigCommon
pusch-ConfigBasic
n-SB: 1
hoppingMode: interSubFrame (0)
pusch-HoppingOffset: 8
.0.. .... enable64QAM: False
ul-ReferenceSignalsPUSCH
..0. .... groupHoppingEnabled: False
groupAssignmentPUSCH: 0
0... .... sequenceHoppingEnabled: False
cyclicShift: 0
pucch-ConfigCommon
deltaPUCCH-Shift: ds2 (1)
nRB-CQI: 4
nCS-AN: 0
n1PUCCH-AN: 12
soundingRS-UL-ConfigCommon: setup (1)
setup
srs-BandwidthConfig: bw0 (0)
srs-SubframeConfig: sc0 (0)
.... 1... ackNackSRS-SimultaneousTransmission: True
uplinkPowerControlCommon
p0-NominalPUSCH: -85dBm
alpha: al07 (4)
p0-NominalPUCCH: -110dBm
deltaFList-PUCCH
deltaF-PUCCH-Format1: deltaF0 (1)
deltaF-PUCCH-Format1b: deltaF3 (1)
deltaF-PUCCH-Format2: deltaF1 (2)
deltaF-PUCCH-Format2a: deltaF2 (2)
deltaF-PUCCH-Format2b: deltaF2 (2)
deltaPreambleMsg3: 8dB (4)
ul-CyclicPrefixLength: len1 (0)
bcch-Config-v1310
modificationPeriodCoeff-v1310: n64 (0)
pcch-Config-v1310
paging-narrowBands-r13: 1
mpdcch-NumRepetition-Paging-r13: r1 (0)
nB-v1310: one64thT (0)
pdsch-ConfigCommon-v1310
pdsch-maxNumRepetitionCEmodeA-r13: r16 (0)
pusch-ConfigCommon-v1310
pusch-maxNumRepetitionCEmodeA-r13: r8 (0)
prach-ConfigCommon-v1310
rsrp-ThresholdsPrachInfoList-r13: 1 item
Item 0
RSRP-Range: RSRP < -140dBm (0)
mpdcch-startSF-CSS-RA-r13: fdd-r13 (0)
fdd-r13: v1 (0)
prach-ParametersListCE-r13: 1 item
Item 0
PRACH-ParametersCE-r13
prach-ConfigIndex-r13: 3
prach-FreqOffset-r13: 2
prach-StartingSubframe-r13: sf2 (0)
maxNumPreambleAttemptCE-r13: n3 (0)
numRepetitionPerPreambleAttempt-r13: n1 (0)
mpdcch-NarrowbandsToMonitor-r13: 1 item
Item 0
mpdcch-NarrowbandsToMonitor-r13 item: 1
mpdcch-NumRepetition-RA-r13: r1 (0)
prach-HoppingConfig-r13: off (1)
pucch-ConfigCommon-v1310
n1PUCCH-AN-InfoList-r13: 1 item
Item 0
N1PUCCH-AN-InfoList-r13 item: 74
pucch-NumRepetitionCE-Msg4-Level0-r13: n1 (0)
ue-TimersAndConstants
t300: ms200 (1)
t301: ms200 (1)
t310: ms200 (3)
n310: n6 (4)
t311: ms10000 (3)
n311: n5 (4)
t300-v1310: ms5000 (4)
t301-v1310: ms5000 (4)
freqInfo
additionalSpectrumEmission: 1
timeAlignmentTimerCommon: infinity (7)