TD-LTE关键过程信令流程解析

TD-LTE 关键过程信令流程解析

TD-LTE 关键过程信令流程解析 1.目的
该文档通过对 TD-LTE 信令流程的说明和解析, 向读者详细描述了 TD-LTE 信令流程和 信令解码,有助于帮助读者在读懂信令的基础上,更好地分析信令,分析问题。

2. 关键过程信令流程解析
E-UTRAN 初始附着过程 1、流程概述——对于过程进行整体描述 附着过程就是 UE 向网络注册的过程。注册成功,UE 和 MME 从都会进入 EMM 注册状态。 网络根据用户 UE 当前状态和签约的信息为用户提供“一直在线”的 IP 服务连接。附着过程 结束, 在 MME 里面为 UE 建立起一个上下文, 在 UE 和 PGW 间为 UE 建立起一条默认 EPS 承载。 UE 刚开机时,先进行物理下行同步,搜索测量进行小区选择,选择到一个 suitable 或 者 acceptable 小区后,驻留并进行附着过程。附着流程图如下:

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TD-LTE 关键过程信令流程解析

Attach 流程图
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TD-LTE 关键过程信令流程解析

说明: 1) 步骤 1~5 会建立 RRC 连接,步骤 6、9 会建立 S1 连接,完成这些过程即标志着

NAS signalling connection 建立完成。 2) 消息 7 的说明:UE 刚开机第一次 attach,使用的 IMSI,无 Identity 过程;后续,

如果有有效的 GUTI,使用 GUTI attach,核心网才会发起 Identity 过程(为上下行直传 消息) 。 3) 消息 10~12 的说明:如果消息 9 带了 UE Radio Capability IE,则 eNB 不会发送

UECapabilityEnquiry 消息给 UE,即没有 10~12 过程;否则会发送,UE 上报无线能力 信息后,eNB 再发 UE Capability Info Indication,给核心网上报 UE 的无线能力信息。 ? 为了减少空口开销,在 IDLE 下 MME 会保存 UE Radio Capability 信息,在

INITIAL CONTEXT SETUP REQUEST 消息会带给 eNB,除非 UE 在执行 attach 或 者"first TAU following GERAN/UTRAN Attach" or "UE radio capability update" TAU 过程(也就是这些过程 MME 不会带 UE Radio Capability 信息给 eNB,并会把本地 保存的 UE Radio Capability 信息删除,eNB 会问 UE 要能力信息,并报给 MME。 注:"UE radio capability update" TAU is only supported for changes of GERAN and UTRAN radio capabilities in ECM-IDLE.) 。 ? ? 4) 在 CONNECTED 下,eNB 会一直保存 UE Radio Capability 信息。 UE 的 E_UTRAN 无线能力信息如果发生改变,需要先 detach,再 attach。

发起 UE 上下文释放(即 21~25)的条件: eNodeB-initiated with cause e.g. O&M Intervention, Unspecified Failure, User

Inactivity, Repeated RRC signalling Integrity Check Failure, Release due to UE generated signalling connection release, etc.; or MME-initiated with cause e.g. authentication failure, detach, etc. 5) 配 eNB 收到 msg3 以后,DCM 给 USM 配置 SRB1,配置完后发送 msg4 给 UE;eNB 置 完 后 发 送 RRCConnectionReconfiguration 给 UE , 收 到

在发送 RRCConnectionReconfiguration 前,DCM 先给 USM 配置 DRB/SRB2 等信息, RRCConnectionReconfigurationComplete 后,控制面再通知用户面资源可用。 6) 消息 13~15 的说明:eNB 发送完消息 13,并不需要等收到消息 14,就直接发送消

息 15。 7) 如果发起 IMSI attach 时,UE 的 IMSI 与另外一个 UE 的 IMSI 重复,并且其他 UE

已经 attach, 则核心网会释放先前的 UE。 如果 IMSI 中的 MNC 与核心网配置的不一致, 则核心网会回复 attach reject。 8) 消息 9 的说明:该消息为 MME 向 eNB 发起的初始上下文建立请求,请求 eNB 建

立承载资源,同时带安全上下文,可能带用户无线能力、切换限制列表等参数。UE 的
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TD-LTE 关键过程信令流程解析

安全能力参数是通过 attach request 消息带给核心网的, 核心网再通过该消息送给 eNB。 UE 的网络能力(安全能力)信息改变的话,需要发起 TAU。

2、消息解析——对于关键参数进行解析 (1)MasterInformationBlock(主信息块) RRC: MasterInformationBlock Message type: BCCH_BCH Direction: Downlink Frame No: 1020 Subframe No: 4 Computer Timestamp: 17:23:26.843 BCCH-BCH-Message message dl-Bandwidth : n100(下行带宽,目前配置为 100PRB,20MHz 带宽) phich-Config phich-Duration : normal(PHICH 持续时间) phich-Resource : half(PHICH 资源大小,Ng 配置为 1/2 即可保证 PHICH 资 源够用,一般系统内的资源占用率不会到 100%,上行单次传输平均占用的资源块数也可能 比较大,此时一个 PHICH 组内实际占用的资源数会比较小,能够保证传输性能。 ) systemFrameNumber : 0xFF spare : 0x0000 (2)SysInfoType1(系统信息块 1) RRC: SysInfoType1 Message type: BCCH_SCH Direction: Downlink Frame No: 1022 Subframe No: 7 Computer Timestamp: 17:23:26.843 BCCH-DL-SCH-Message message c1 systemInformationBlockType1 cellAccessRelatedInfo plmn-IdentityList PLMN-IdentityInfo plmn-Identity mcc MCC-MNC-Digit : 4 MCC-MNC-Digit : 6 MCC-MNC-Digit : 0 mnc MCC-MNC-Digit : 0 MCC-MNC-Digit : 0
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TD-LTE 关键过程信令流程解析

cellReservedForOperatorUse : notReserved trackingAreaCode : 0x0200(小区所属跟踪区的 ID) cellIdentity : 0x00099020 cellBarred : notBarred intraFreqReselection : allowed csg-Indication : false cellSelectionInfo q-RxLevMin : -60(小区重选最小信道要求,目前配置为-60dBm) p-Max : 23(UE 最大发射功率,目前配置为 23dBm) freqBandIndicator : 38(E-UTRA 工作频段,38 指 2570Mhz-2620Mhz) schedulingInfoList SchedulingInfo si-Periodicity : rf32 sib-MappingInfo sibType3 sibType4 tdd-Config subframeAssignment : sa1(上下行子帧配置,sa1 指 2U2D) specialSubframePatterns : ssp7 (特殊子帧配置, ssp7 指 10: 2 :2) si-WindowLength : ms10 systemInfoValueTag : 0 (3)SysInfo(系统信息块) RRC: SysInfo Message type: BCCH_SCH Direction: Downlink Frame No: 0 Subframe No: 5 Computer Timestamp: 17:23:26.843 BCCH-DL-SCH-Message message c1 systemInformation criticalExtensions systemInformation-r8 sib-TypeAndInfo sib2 radioResourceConfigCommon rach-ConfigCommon preambleInfo numberOfRA-Preambles : n48(竞争前导 码数量,预留 48 个 Preamble 码用于竞争随机接入) preamblesGroupAConfig sizeOfRA-PreamblesGroupA : n48 messageSizeGroupA : b56
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TD-LTE 关键过程信令流程解析

messagePowerOffsetGroupB : dB8 powerRampingParameters powerRampingStep : dB2 preambleInitialReceivedTargetPower : dBm-106 ra-SupervisionInfo preambleTransMax : n4 ra-ResponseWindowSize : sf10 mac-ContentionResolutionTimer : sf48 maxHARQ-Msg3Tx : 4 bcch-Config modificationPeriodCoeff : n4 pcch-Config defaultPagingCycle : rf64 nB : halfT prach-Config rootSequenceIndex : 24(前导码根序列逻辑 索引,当采用 Preamble Format0~3 时,ZC 根序列的选择与当前小区是否为高速小区有关, 当采用 Preamble Format0~3 且为高速小区时,RootSeqIndex 的取值与 Ncs 有关,Preamble 格式影响 RootSeqIndex 的取值范围以及选择原则) prach-ConfigInfo prach-ConfigIndex : 3 highSpeedFlag : false zeroCorrelationZoneConfig : 3 prach-FreqOffset : 17 pdsch-ConfigCommon referenceSignalPower : 15(小区参考信号 功率,15 对应全带宽等效总功率 45.79dBm) p-b : 1(无 CRS 的 OFDM 符号上的数据 RE 与 有 CRS 的 OFDM 符号上数据 RE 的能量之比,一般取 1,即功率比为 1:1) pusch-ConfigCommon pusch-ConfigBasic n-SB : 4 hoppingMode : interSubFrame pusch-HoppingOffset : 33 enable64QAM : true ul-ReferenceSignalsPUSCH groupHoppingEnabled : false groupAssignmentPUSCH : 0 sequenceHoppingEnabled : false cyclicShift : 0 pucch-ConfigCommon deltaPUCCH-Shift : ds2 nRB-CQI : 2
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TD-LTE 关键过程信令流程解析

nCS-AN : 0 n1PUCCH-AN : 36 soundingRS-UL-ConfigCommon setup srs-BandwidthConfig : bw0 srs-SubframeConfig : sc0 ackNackSRS-SimultaneousTransmission : true srs-MaxUpPts : true uplinkPowerControlCommon p0-NominalPUSCH : -85(持续调度期望接收 功率,根据需要随时修改) alpha : al1 p0-NominalPUCCH : -112(PUCCH 期望功率, 根据需要随时修改) deltaFList-PUCCH deltaF-PUCCH-Format1 : deltaF0 deltaF-PUCCH-Format1b : deltaF1 deltaF-PUCCH-Format2 : deltaF0 deltaF-PUCCH-Format2a : deltaF2 deltaF-PUCCH-Format2b : deltaF2 deltaPreambleMsg3 : 4 ul-CyclicPrefixLength : len1 ue-TimersAndConstants t300 : ms2000(T300 定时器时长,当 UE 发送 RRC CONNECTION REQUEST 消息后启动 T300 定时器,当收到 RRC CONNECTION SETUP 消息后停止 T300 定时器。一旦超时,若 RRC CONNECTION REQUEST 消息重发次数小于常量 N300 则重发 RRC CONNECTION REQUEST,否则进入空闲模式。T300 的设置应结合 UE、UTRAN 处理时延以 及传播时延考虑,T300 设置越大,UE 等待时间越长。N300 设置越大,RRC 连接成功建立的 可能性越高,同时用于 RRC 建立的时间也可能越长,有可能出现某个 UE 反复尝试接入和发 送连接建立请求,而对其它用户造成较强干扰的情况。 ) t301 : ms600(用户摘机定时器) t310 : ms2000 n310 : n20 t311 : ms1000 n311 : n1 freqInfo additionalSpectrumEmission : 1 timeAlignmentTimerCommon : infinity sib3 cellReselectionInfoCommon q-Hyst : dB2 cellReselectionServingFreqInfo s-NonIntraSearch : 2
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TD-LTE 关键过程信令流程解析

threshServingLow : 0 cellReselectionPriority : 3 intraFreqCellReselectionInfo q-RxLevMin : -53 p-Max : 23 (UE 最大发射功率, 目前配置为 23dBm) s-IntraSearch : 3 allowedMeasBandwidth : mbw6 presenceAntennaPort1 : true neighCellConfig : 0x40 t-ReselectionEUTRA : 3 sib4 intraFreqNeighCellList IntraFreqNeighCellInfo physCellId : 0 q-OffsetCell : dB0 IntraFreqNeighCellInfo physCellId : 1 q-OffsetCell : dB0 IntraFreqNeighCellInfo physCellId : 4 q-OffsetCell : dB0 IntraFreqNeighCellInfo physCellId : 5 q-OffsetCell : dB0 (4)Attach Request Message type: EPS MM Direction: Uplink Computer Timestamp: 17:23:02.843 Frame No: 674 Subframe No: 6 Attach Request Security header type: (0) Plain NAS message, not security protected protocol_discriminator : EPS Mobility Management NAS EPS Mobility Management Message Type : (0x41) Attach request Type of security context flag (TSC): (0) Native security context NAS key set identifier: (0) Spare bit(s): 0 EPS attach type: (1) EPS attach EPS mobile identity - Old GUTI or IMSI Length : 11 octets odd/even indic: 0 Type of identity: (6) GUTI Mobile Country Code (MCC): (460) China (People's Republic of) (移动国家 码)
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TD-LTE 关键过程信令流程解析

Mobile Network Code (MNC): (00) China Mobile (移动网络码) MME Group ID: 32768 MME Code: 50 M-TMSI: 0x203f09(临时移动用户识别) UE network capability Length : 4 octets EEA0: (1) Support 128-EEA1: (1) Support 128-EEA2: (1) Support EEA3: (0) Not support EEA4: (0) Not support EEA5: (0) Not support EEA6: (0) Not support EEA7: (0) Not support EIA0: (1) Support 128-EIA1: (1) Support 128-EIA2: (1) Support EIA3: (0) Not support EIA4: (0) Not support EIA5: (0) Not support EIA6: (0) Not support EIA7: (0) Not support UEA0: (0) Not support UEA1: (0) Not support UEA2: (0) Not support UEA3: (0) Not support UEA4: (0) Not support UEA5: (0) Not support UEA6: (0) Not support UEA7: (0) Not support UCS2 support (UCS2): (0) Not support UMTS integrity algorithm UIA1: (0) Not support UMTS integrity algorithm UIA2: (0) Not support UMTS integrity algorithm UIA3: (0) Not support UMTS integrity algorithm UIA4: (0) Not support UMTS integrity algorithm UIA5: (0) Not support UMTS integrity algorithm UIA6: (0) Not support UMTS integrity algorithm UIA7: (0) Not support ESM message container Length : 29 octets ESM message container contents: 2 1 d0 11 27 17 80 80 21 10 1 1 0 10 81 6 0 0 0 0 83 6 0 0 0 0 0 a 0 0000 .... = EPS bearer identity : 0 .... 0010 = protocol_discriminator : (2) EPS session management
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TD-LTE 关键过程信令流程解析

messages Procedure transaction identity : 1 NAS EPS session management messages : (0xd0) PDN connectivity request PDN type: (1) IPv4 Request type: (1) Initial request Protocol Configuration Options Element ID : 39 Length : 23 octets Ext: 1 Configuration protocol: (0) PPP Protocol information: [0]: Protocol ID : IPCP (Hex 8021) Contents length: 16 octets Protocal contents: (Hex) 01 01 00 10 81 06 00 00 00 00 83 06 00 00 00 00 [1]: Protocol ID : (Hex A) Contents length: 0 octets Protocal contents: (Hex) Tracking area identity - Last visited registered TAI Element ID : 82 Mobile Country Code (MCC): (460) China (People's Republic of) Mobile Network Code (MNC): (00) China Mobile Tracking area code(TAC): 0x200 (5)RRCConnectionRequest(建立一个 RRC 连接) RRC: RRCConnectionRequest Message type: CCCH_UL Direction: Uplink Frame No: 675 Subframe No: 9 Computer Timestamp: 17:23:02.843 UL-CCCH-Message message c1 rrcConnectionRequest criticalExtensions rrcConnectionRequest-r8 ue-Identity(初始 UE 标识) randomValue : 0x397737492F establishmentCause : mo-Signalling(建立原因) spare : 0x00 (6)RRCConnectionSetup(建立一个 SRB1) RC: RRCConnectionSetup
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TD-LTE 关键过程信令流程解析

Message type: CCCH_DL Direction: Downlink Frame No: 680 Subframe No: 2 Computer Timestamp: 17:23:02.953 DL-CCCH-Message message c1 rrcConnectionSetup rrc-TransactionIdentifier : 0(RRC 操作标识) criticalExtensions c1 rrcConnectionSetup-r8 radioResourceConfigDedicated srb-ToAddModList SRB-ToAddMod srb-Identity : 1 rlc-Config explicitValue am ul-AM-RLC t-PollRetransmit : ms200 pollPDU : p64 pollByte : kB100 maxRetxThreshold : t6 dl-AM-RLC t-Reordering : ms50 t-StatusProhibit : ms0 logicalChannelConfig explicitValue ul-SpecificParameters priority : 1 prioritisedBitRate : infinity bucketSizeDuration : ms50 logicalChannelGroup : 0 mac-MainConfig explicitValue ul-SCH-Config maxHARQ-Tx : n4(上行最大传输次数, 一般为 4 次确保传输数据成功) periodicBSR-Timer : sf5(BSR 周期定 时器时长,一般为了 TCP 等业务流畅将此定时器设置较短,目前配置为 5ms) retxBSR-Timer : sf320
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TD-LTE 关键过程信令流程解析

ttiBundling : false(TTI 捆绑开启指 示) timeAlignmentTimerDedicated : infinity phr-Config setup periodicPHR-Timer : sf1000 prohibitPHR-Timer : sf200 dl-PathlossChange : dB3 physicalConfigDedicated pdsch-ConfigDedicated p-a : dB-3(无 CRS 的 OFDM 符号上数据 RE 与 CRS RE 的能量之比,一般取 3dB,即为功率比为 1:2) pucch-ConfigDedicated ackNackRepetition : release tdd-AckNackFeedbackMode : bundling pusch-ConfigDedicated betaOffset-ACK-Index : 9 betaOffset-RI-Index : 10 betaOffset-CQI-Index : 13 uplinkPowerControlDedicated p0-UE-PUSCH : 0(非持续调度信噪比增量, 用户级的非持续调度业务目标信噪比调整量) deltaMCS-Enabled : en0 accumulationEnabled : false p0-UE-PUCCH : 0 pSRS-Offset : 5 filterCoefficient : fc4 tpc-PDCCH-ConfigPUCCH setup tpc-RNTI : 0x3002 tpc-Index(PUSCH 功控 DCI) indexOfFormat3 : 1 tpc-PDCCH-ConfigPUSCH setup tpc-RNTI : 0x0802 tpc-Index indexOfFormat3 : 1 cqi-ReportConfig nomPDSCH-RS-EPRE-Offset : 0 cqi-ReportPeriodic setup cqi-PUCCH-ResourceIndex : 0 cqi-pmi-ConfigIndex : 18 cqi-FormatIndicatorPeriodic :
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TD-LTE 关键过程信令流程解析

widebandCQI ri-ConfigIndex : 322 simultaneousAckNackAndCQI : true soundingRS-UL-ConfigDedicated setup srs-Bandwidth : bw0(小区 SRS 带宽配 置,其中 bw0 对应 b = 0,以此类推,参数 b 指示 SRS 传输所在频带层序号,某个频带层中 单个频带的带宽与当前系统上行带宽有关) srs-HoppingBandwidth : hbw0 freqDomainPosition : 0 duration : true srs-ConfigIndex : 25 transmissionComb : 0 cyclicShift : cs0 antennaInfo explicitValue transmissionMode : tm3 (下行传输模式, 目前配置为 TM3) codebookSubsetRestriction n2TxAntenna-tm3 : 0xC0 ue-TransmitAntennaSelection : release schedulingRequestConfig setup sr-PUCCH-ResourceIndex : 0 sr-ConfigIndex : 3 dsr-TransMax : n32 (7)RRCConnectionSetupComplete(确认一个 RRC 连接已经建立) RRC: RRCConnectionSetupComplete Message type: DCCH_UL Direction: Uplink Frame No: 681 Subframe No: 0 Computer Timestamp: 17:23:02.953 UL-DCCH-Message message c1 rrcConnectionSetupComplete rrc-TransactionIdentifier : 0 criticalExtensions c1 rrcConnectionSetupComplete-r8 selectedPLMN-Identity : 1 registeredMME(MME 注册发起)
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TD-LTE 关键过程信令流程解析

mmegi : 0x8000 mmec : 0x32 dedicatedInfoNAS : 0x1700000000030741010BF664F00080003200203F0904E0E00000001D0201D0112717808021100 1010010810600000000830600000000000A005264F0000200 Attach Request Security header type: (1) Integrity protected protocol_discriminator : EPS Mobility Management Message authentication code: 0x0 Sequence number: 3 Security header type: (0) Plain NAS message, not security protected protocol_discriminator : EPS Mobility Management(7) NAS EPS Mobility Management Message Type : (0x41) Attach request Type of security context flag (TSC): (0) Native security context NAS key set identifier: (0) Spare bit(s): 0 EPS attach type: (1) EPS attach EPS mobile identity - Old GUTI or IMSI Length : 11 octets odd/even indic: 0 Type of identity: (6) GUTI Mobile Country Code (MCC): (460) China (People's Republic of) Mobile Network Code (MNC): (00) China Mobile MME Group ID: 32768 MME Code: 50 M-TMSI: 0x203f09 UE network capability Length : 4 octets EEA0: (1) Support 128-EEA1: (1) Support 128-EEA2: (1) Support EEA3: (0) Not support EEA4: (0) Not support EEA5: (0) Not support EEA6: (0) Not support EEA7: (0) Not support EIA0: (1) Support 128-EIA1: (1) Support 128-EIA2: (1) Support EIA3: (0) Not support EIA4: (0) Not support EIA5: (0) Not support EIA6: (0) Not support EIA7: (0) Not support
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TD-LTE 关键过程信令流程解析

UEA0: (0) Not support UEA1: (0) Not support UEA2: (0) Not support UEA3: (0) Not support UEA4: (0) Not support UEA5: (0) Not support UEA6: (0) Not support UEA7: (0) Not support UCS2 support (UCS2): (0) Not support UMTS integrity algorithm UIA1: (0) Not support UMTS integrity algorithm UIA2: (0) Not support UMTS integrity algorithm UIA3: (0) Not support UMTS integrity algorithm UIA4: (0) Not support UMTS integrity algorithm UIA5: (0) Not support UMTS integrity algorithm UIA6: (0) Not support UMTS integrity algorithm UIA7: (0) Not support ESM message container Length : 29 octets ESM message container contents: 2 1 d0 11 27 17 80 80 21 10 1 1 0 10 81 6 0 0 0 0 83 6 0 0 0 0 0 a 0 0000 .... = EPS bearer identity : 0 .... 0010 = protocol_discriminator : (2) EPS session management messages Procedure transaction identity : 1 NAS EPS session management messages : (0xd0) PDN connectivity request PDN type: (1) IPv4 Request type: (1) Initial request Protocol Configuration Options Element ID : 39 Length : 23 octets Ext: 1 Configuration protocol: (0) PPP Protocol information: [0]: Protocol ID : IPCP (Hex 8021) Contents length: 16 octets Protocal contents: (Hex) 01 01 00 10 81 06 00 00 00 00 83 06 00 00 00 00 [1]: Protocol ID : (Hex A) Contents length: 0 octets Protocal contents: (Hex) Tracking area identity - Last visited registered TAI Element ID : 82
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TD-LTE 关键过程信令流程解析

Mobile Country Code (MCC): (460) China (People's Republic of) Mobile Network Code (MNC): (00) China Mobile Tracking area code(TAC): 0x200(跟踪区代码) (8)UECapabilityEnquiry(UE 能力查询) RRC: UECapabilityEnquiry Message type: DCCH_DL Direction: Downlink Frame No: 697 Subframe No: 1 Computer Timestamp: 17:23:03.046 DL-DCCH-Message message c1 ueCapabilityEnquiry rrc-TransactionIdentifier : 0 criticalExtensions c1 ueCapabilityEnquiry-r8 ue-CapabilityRequest : eutra (9)UECapabilityInformation(UE 能力信息) RRC: UECapabilityInformation Message type: DCCH_UL Direction: Uplink Frame No: 697 Subframe No: 2 Computer Timestamp: 17:23:03.046 UL-DCCH-Message message c1 ueCapabilityInformation rrc-TransactionIdentifier : 0 criticalExtensions c1 ueCapabilityInformation-r8 ue-CapabilityRAT-ContainerList UE-CapabilityRAT-Container rat-Type : eutra ueCapabilityRAT-Container accessStratumRelease : rel8 ue-Category : 3 pdcp-Parameters supportedROHC-Profiles profile0x0001 : false profile0x0002 : false
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TD-LTE 关键过程信令流程解析

profile0x0003 : false profile0x0004 : false profile0x0006 : false profile0x0101 : false profile0x0102 : false profile0x0103 : false profile0x0104 : false maxNumberROHC-ContextSessions : cs2 phyLayerParameters ue-TxAntennaSelectionSupported : false ue-SpecificRefSigsSupported : true rf-Parameters supportedBandListEUTRA SupportedBandEUTRA bandEUTRA : 38 halfDuplex : false measParameters bandListEUTRA BandInfoEUTRA interFreqBandList InterFreqBandInfo interFreqNeedForGaps : true InterFreqBandInfo interFreqNeedForGaps : true InterFreqBandInfo interFreqNeedForGaps : true BandInfoEUTRA interFreqBandList InterFreqBandInfo interFreqNeedForGaps : true InterFreqBandInfo interFreqNeedForGaps : true InterFreqBandInfo interFreqNeedForGaps : true BandInfoEUTRA interFreqBandList InterFreqBandInfo
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TD-LTE 关键过程信令流程解析

interFreqNeedForGaps : true InterFreqBandInfo interFreqNeedForGaps : true InterFreqBandInfo interFreqNeedForGaps : true BandInfoEUTRA interFreqBandList InterFreqBandInfo interFreqNeedForGaps : true InterFreqBandInfo interFreqNeedForGaps : true InterFreqBandInfo interFreqNeedForGaps : true BandInfoEUTRA interFreqBandList InterFreqBandInfo interFreqNeedForGaps : true InterFreqBandInfo interFreqNeedForGaps : true InterFreqBandInfo interFreqNeedForGaps : true featureGroupIndicators : 0xE60D1880 interRAT-Parameters (10)SecurityModeCommand(安全模式) RRC: SecurityModeCommand Message type: DCCH_DL Direction: Downlink Frame No: 702 Subframe No: 7 Computer Timestamp: 17:23:03.156 DL-DCCH-Message message c1 securityModeCommand rrc-TransactionIdentifier : 0
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TD-LTE 关键过程信令流程解析

criticalExtensions c1 securityModeCommand-r8 securityConfigSMC securityAlgorithmConfig cipheringAlgorithm : eea0(加密算法类型) integrityProtAlgorithm : spare1(完整性保护 算法类型) (11)SecurityModeComplete(安全模式完成) RRC: SecurityModeComplete Message type: DCCH_UL Direction: Uplink Frame No: 703 Subframe No: 0 Computer Timestamp: 17:23:03.156 UL-DCCH-Message message c1 securityModeComplete rrc-TransactionIdentifier : 0 criticalExtensions : securityModeComplete-r8 (12) RRCConnectionReconfiguration(RRC 连接重配置) RRC: RRCConnectionReconfiguration Message type: DCCH_DL Direction: Downlink Frame No: 703 Subframe No: 4 Computer Timestamp: 17:23:03.156 DL-DCCH-Message message c1 rrcConnectionReconfiguration rrc-TransactionIdentifier : 0 criticalExtensions c1 rrcConnectionReconfiguration-r8 measConfig measObjectToAddModList MeasObjectToAddMod measObjectId : 1 measObject measObjectEUTRA carrierFreq : 37900(小区中心频 点,按照实际设计配置.目前配置为中心频点为 2585MHz)
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TD-LTE 关键过程信令流程解析

allowedMeasBandwidth : mbw6 presenceAntennaPort1 : true neighCellConfig : 0x40 offsetFreq : dB0 cellsToAddModList CellsToAddMod cellIndex : 1 physCellId : 1 cellIndividualOffset dB0 CellsToAddMod cellIndex : 2 physCellId : 0 cellIndividualOffset dB0 CellsToAddMod cellIndex : 3 physCellId : 2 cellIndividualOffset dB0

:

:

:

reportConfigToAddModList ReportConfigToAddMod reportConfigId : 1 reportConfig reportConfigEUTRA triggerType event eventId eventA3(A3 事件) a3-Offset : 2 (A3 事件触发偏移值,影响切换时两小区间功率差判断,目前配置为 2dB) reportOnLeave : false hysteresis : 4(事件触发 滞后因子,与 a3-Offset 共同影响切换时两小区间功率差判断,目前配置为 2dB) timeToTrigger : ms512 (事 件触发持续时间,目前配置为 512ms) triggerQuantity : rsrp reportQuantity : both maxReportCells : 8 reportInterval : min6 reportAmount : r1 measIdToAddModList MeasIdToAddMod
20

TD-LTE 关键过程信令流程解析

measId : 1 measObjectId : 1 reportConfigId : 1 quantityConfig quantityConfigEUTRA filterCoefficientRSRP : fc4 filterCoefficientRSRQ : fc4 s-Measure : 0 speedStatePars setup mobilityStateParameters t-Evaluation : s120 t-HystNormal : s60 n-CellChangeMedium : 5 n-CellChangeHigh : 10 timeToTrigger-SF sf-Medium : lDot0 sf-High : lDot0 dedicatedInfoNASList DedicatedInfoNAS : 0x27000000000207420126060064F000020000325201C1010816036C7465056D6E633030066D636 334363004677072730501AC100E77270E8080210A0301000A810614463206500BF664F000800032 00203F0A4A0364F070 radioResourceConfigDedicated srb-ToAddModList SRB-ToAddMod srb-Identity : 2 rlc-Config explicitValue am ul-AM-RLC t-PollRetransmit : ms200 pollPDU : p64 pollByte : kB100 maxRetxThreshold : t6 dl-AM-RLC t-Reordering : ms50 t-StatusProhibit : ms0 logicalChannelConfig explicitValue ul-SpecificParameters priority : 3 prioritisedBitRate : infinity
21

TD-LTE 关键过程信令流程解析

bucketSizeDuration : ms50 logicalChannelGroup : 0 drb-ToAddModList DRB-ToAddMod eps-BearerIdentity : 5 drb-Identity : 3 pdcp-Config discardTimer : ms100 rlc-UM pdcp-SN-Size : len12bits headerCompression : notUsed rlc-Config um-Bi-Directional ul-UM-RLC sn-FieldLength : size10 dl-UM-RLC sn-FieldLength : size10 t-Reordering : ms50 logicalChannelIdentity : 3 logicalChannelConfig ul-SpecificParameters priority : 11 prioritisedBitRate : kBps8 bucketSizeDuration : ms100 logicalChannelGroup : 3 mac-MainConfig explicitValue ul-SCH-Config maxHARQ-Tx : n4 periodicBSR-Timer : sf5 retxBSR-Timer : sf320 ttiBundling : false timeAlignmentTimerDedicated : infinity phr-Config setup periodicPHR-Timer : sf1000 prohibitPHR-Timer : sf200 dl-PathlossChange : dB3 physicalConfigDedicated pdsch-ConfigDedicated p-a : dB-3 pusch-ConfigDedicated betaOffset-ACK-Index : 9 betaOffset-RI-Index : 10
22

TD-LTE 关键过程信令流程解析

betaOffset-CQI-Index : 13 uplinkPowerControlDedicated p0-UE-PUSCH : 0 deltaMCS-Enabled : en0 accumulationEnabled : false p0-UE-PUCCH : 0 pSRS-Offset : 5 filterCoefficient : fc4 antennaInfo explicitValue transmissionMode : tm3 codebookSubsetRestriction n2TxAntenna-tm3 : 0xC0 ue-TransmitAntennaSelection

:

release Attach Accept Security header type: (2) Integrity protected and ciphered protocol_discriminator : EPS Mobility Management Message authentication code: 0x0 Sequence number: 2 Security header type: (0) Plain NAS message, not security protected protocol_discriminator : EPS Mobility Management(7) NAS EPS Mobility Management Message Type : (0x42) Attach accept 0000 0... = Spare bit(s): 0 .... .001 = Attach result: (1) EPS only GPRS Timer GPRS Timer: 6 min 001. .... = Unit: (01) value is incremented in multiples of 1 minute ...0 0110 = Timer value: 6 Tracking area identity list - TAI list Length : 6 octets Spare bit(s): 0 .00. .... = Type of list: (0) list of TACs belonging to one PLMN, with non-consecutive TAC values Number of elements [+1 = 1 element(s)] Mobile Country Code (MCC): (460) China (People's Republic of) Mobile Network Code (MNC): (00) China Mobile Tracking area code(TAC): 0x200 ESM message container Length : 50 octets ESM message container contents: 52 1 c1 1 8 16 3 6c 74 65 5 6d 6e 63 30 30 6 6d 63 63 34 36 30 4 67 70 72 73 5 1 ac 10 e 77 27 e 80 80 21 a 3 1 0 a 81 6 14 46 32 6 0101 .... = EPS bearer identity : 5
23

TD-LTE 关键过程信令流程解析

.... 0010 = protocol_discriminator : (2) EPS session management messages Procedure transaction identity : 1 NAS EPS session management messages : (0xc1) Activate default EPS bearer context request EPS quality of service Length : 1 octets Quality of Service Class Identifier (QCI): (8) QCI 8 Access Point Name Length : 22 octets APN: lte.mnc00.mcc460.gprs PDN address Length : 5 octets Spare bit(s): 0 PDN type: (1) IPv4 PDN IPv4: 172.16.14.119. Protocol Configuration Options Element ID : 39 Length : 14 octets Ext: 1 Configuration protocol: (0) PPP Protocol information: [0]: Protocol ID : IPCP (Hex 8021) Contents length: 10 octets Protocal contents: (Hex) 03 01 00 0a 81 06 14 46 32 06 EPS mobile identity - GUTI Element ID : 80 Length : 11 octets odd/even indic: 0 Type of identity: (6) GUTI Mobile Country Code (MCC): (460) China (People's Republic of) Mobile Network Code (MNC): (00) China Mobile MME Group ID: 32768 MME Code: 50 M-TMSI: 0x203f0a PLMN list - Equivalent PLMNs Element ID : 74 Length : 3 octets Length of PLMN List contents: 3 MCC: 460 MNC: 07 (13)RRCConnectionSetupComplete(确认 RRC 重配置完成) RRC: RRCConnectionSetupComplete
24

TD-LTE 关键过程信令流程解析

Message type: DCCH_UL Direction: Uplink Frame No: 681 Subframe No: 0 Computer Timestamp: 17:23:02.953 UL-DCCH-Message message c1 rrcConnectionSetupComplete rrc-TransactionIdentifier : 0 criticalExtensions c1 rrcConnectionSetupComplete-r8 selectedPLMN-Identity : 1 registeredMME mmegi : 0x8000 mmec : 0x32 dedicatedInfoNAS : 0x1700000000030741010BF664F00080003200203F0904E0E00000001D0201D0112717808021100 1010010810600000000830600000000000A005264F0000200 Attach Request Security header type: (1) Integrity protected protocol_discriminator : EPS Mobility Management Message authentication code: 0x0 Sequence number: 3 Security header type: (0) Plain NAS message, not security protected protocol_discriminator : EPS Mobility Management(7) NAS EPS Mobility Management Message Type : (0x41) Attach request Type of security context flag (TSC): (0) Native security context NAS key set identifier: (0) Spare bit(s): 0 EPS attach type: (1) EPS attach EPS mobile identity - Old GUTI or IMSI Length : 11 octets odd/even indic: 0 Type of identity: (6) GUTI Mobile Country Code (MCC): (460) China (People's Republic of) Mobile Network Code (MNC): (00) China Mobile MME Group ID: 32768 MME Code: 50 M-TMSI: 0x203f09 UE network capability Length : 4 octets EEA0: (1) Support
25

TD-LTE 关键过程信令流程解析

128-EEA1: (1) Support 128-EEA2: (1) Support EEA3: (0) Not support EEA4: (0) Not support EEA5: (0) Not support EEA6: (0) Not support EEA7: (0) Not support EIA0: (1) Support 128-EIA1: (1) Support 128-EIA2: (1) Support EIA3: (0) Not support EIA4: (0) Not support EIA5: (0) Not support EIA6: (0) Not support EIA7: (0) Not support UEA0: (0) Not support UEA1: (0) Not support UEA2: (0) Not support UEA3: (0) Not support UEA4: (0) Not support UEA5: (0) Not support UEA6: (0) Not support UEA7: (0) Not support UCS2 support (UCS2): (0) Not support UMTS integrity algorithm UIA1: (0) Not support UMTS integrity algorithm UIA2: (0) Not support UMTS integrity algorithm UIA3: (0) Not support UMTS integrity algorithm UIA4: (0) Not support UMTS integrity algorithm UIA5: (0) Not support UMTS integrity algorithm UIA6: (0) Not support UMTS integrity algorithm UIA7: (0) Not support ESM message container Length : 29 octets ESM message container contents: 2 1 d0 11 27 17 80 80 21 10 1 1 0 10 81 6 0 0 0 0 83 6 0 0 0 0 0 a 0 0000 .... = EPS bearer identity : 0 .... 0010 = protocol_discriminator : (2) EPS session management messages Procedure transaction identity : 1 NAS EPS session management messages : (0xd0) PDN connectivity request PDN type: (1) IPv4 Request type: (1) Initial request Protocol Configuration Options Element ID : 39
26

TD-LTE 关键过程信令流程解析

Length : 23 octets Ext: 1 Configuration protocol: (0) PPP Protocol information: [0]: Protocol ID : IPCP (Hex 8021) Contents length: 16 octets Protocal contents: (Hex) 01 01 00 10 81 06 00 00 00 00 83 06 00 00 00 00 [1]: Protocol ID : (Hex A) Contents length: 0 octets Protocal contents: (Hex) Tracking area identity - Last visited registered TAI Element ID : 82 Mobile Country Code (MCC): (460) China (People's Republic of) Mobile Network Code (MNC): (00) China Mobile Tracking area code(TAC): 0x200 (14)Attach Accept(附着接受) Message type: EPS MM Direction: Downlink Computer Timestamp: 17:23:03.171 Frame No: 704 Subframe No: 5 Attach Accept Security header type: (0) Plain NAS message, not security protected protocol_discriminator : EPS Mobility Management NAS EPS Mobility Management Message Type : (0x42) Attach accept 0000 0... = Spare bit(s): 0 .... .001 = Attach result: (1) EPS only GPRS Timer GPRS Timer: 6 min 001. .... = Unit: (01) value is incremented in multiples of 1 minute ...0 0110 = Timer value: 6 Tracking area identity list - TAI list Length : 6 octets Spare bit(s): 0 .00. .... = Type of list: (0) list of TACs belonging to one PLMN, with non-consecutive TAC values Number of elements [+1 = 1 element(s)] Mobile Country Code (MCC): (460) China (People's Republic of) Mobile Network Code (MNC): (00) China Mobile Tracking area code(TAC): 0x200 ESM message container
27

TD-LTE 关键过程信令流程解析

Length : 50 octets ESM message container contents: 52 1 c1 1 8 16 3 6c 74 65 5 6d 6e 63 30 30 6 6d 63 63 34 36 30 4 67 70 72 73 5 1 ac 10 e 77 27 e 80 80 21 a 3 1 0 a 81 6 14 46 32 6 0101 .... = EPS bearer identity : 5 .... 0010 = protocol_discriminator : (2) EPS session management messages Procedure transaction identity : 1 NAS EPS session management messages : (0xc1) Activate default EPS bearer context request EPS quality of service Length : 1 octets Quality of Service Class Identifier (QCI): (8) QCI 8 Access Point Name Length : 22 octets APN: lte.mnc00.mcc460.gprs PDN address Length : 5 octets Spare bit(s): 0 PDN type: (1) IPv4 PDN IPv4: 172.16.14.119. Protocol Configuration Options Element ID : 39 Length : 14 octets Ext: 1 Configuration protocol: (0) PPP Protocol information: [0]: Protocol ID : IPCP (Hex 8021) Contents length: 10 octets Protocal contents: (Hex) 03 01 00 0a 81 06 14 46 32 06 EPS mobile identity - GUTI Element ID : 80 Length : 11 octets odd/even indic: 0 Type of identity: (6) GUTI Mobile Country Code (MCC): (460) China (People's Republic of) Mobile Network Code (MNC): (00) China Mobile MME Group ID: 32768 MME Code: 50 M-TMSI: 0x203f0a PLMN list - Equivalent PLMNs Element ID : 74 Length : 3 octets
28

TD-LTE 关键过程信令流程解析

Length of PLMN List contents: 3 MCC: 460 MNC: 07 (15)Activate Default EPS Bearer Context Request(建立默认 EPS 承载请求) Message type: EPS SM Direction: Downlink Computer Timestamp: 17:23:03.171 Frame No: 704 Subframe No: 6 Activate Default EPS Bearer Context Request 0101 .... = EPS bearer identity : 5 .... 0010 = protocol_discriminator : (2) EPS session management messages Procedure transaction identity : 1 NAS EPS session management messages : (0xc1) Activate default EPS bearer context request EPS quality of service Length : 1 octets Quality of Service Class Identifier (QCI): (8) QCI 8 Access Point Name Length : 22 octets APN: lte.mnc00.mcc460.gprs PDN address Length : 5 octets Spare bit(s): 0 PDN type: (1) IPv4 PDN IPv4: 172.16.14.119. Protocol Configuration Options Element ID : 39 Length : 14 octets Ext: 1 Configuration protocol: (0) PPP Protocol information: [0]: Protocol ID : IPCP (Hex 8021) Contents length: 10 octets Protocal contents: (Hex) 03 01 00 0a 81 06 14 46 32 06 (16)Activate Default EPS Bearer Context Accept(建立默认 EPS 承载接受) Message type: EPS SM Direction: Uplink Computer Timestamp: 17:23:03.171 Frame No: 704 Subframe No: 8 Activate Default EPS Bearer Context Accept 0101 .... = EPS bearer identity : 5
29

TD-LTE 关键过程信令流程解析

.... 0010 = protocol_discriminator : (2) EPS session management messages Procedure transaction identity : 0 NAS EPS session management messages : (0xc2) Activate default EPS bearer context accept (17)Attach Complete(附着完成) Message type: EPS MM Direction: Uplink Computer Timestamp: 17:23:03.187 Frame No: 704 Subframe No: 9 Attach Complete Security header type: (0) Plain NAS message, not security protected protocol_discriminator : EPS Mobility Management NAS EPS Mobility Management Message Type : (0x43) Attach complete ESM message container Length : 3 octets ESM message container contents: 52 0 c2 0101 .... = EPS bearer identity : 5 .... 0010 = protocol_discriminator : (2) EPS session management messages Procedure transaction identity : 0 NAS EPS session management messages : (0xc2) Activate default EPS bearer context accept

切换过程 1、流程概述——对于过程进行整体描述 在移动通信系统中,当处于通信状态的 UE 从一个小区移动到另外一个小区,或者服务 小区的链路质量恶化,或者服务小区负荷过高,通过负荷控制将 UE 调整到另外一个小区等 原因,为了保证通信的连续性,网络需要将 UE 切换到另外一个小区,由另外一个小区为该 UE 继续提供服务。 切换算法的基本思想是根据 UE 的测量上报选择强度或质量最好的邻小区作为目标小 区,设计合理的切换触发条件,既要避免触发不必要的切换过程,又要避免用户掉话。 X2 切换是指当切换发生在不同基站间,MME 不变时,原基站选择通过 X2 口进行切换。 目前我们系统实现的 X2 切换是在 Serving GW 没有改变的情况下, UE 发送 A3 测量报告, 原小区触发切换,将 UE 切换到目标小区的过程。本文档主要对 Serving GW 不变时的 X2 切 换进行描述。 X2 接口切换的正常流程如下图所示:
30

TD-LTE 关键过程信令流程解析

UE

Source eNB

Target eNB

MME

Serving GW

Packet data 2. MeasurementReport

Packet data

legend 3a. HO Decison 4. Handover Request 5. Admission Control 6. Handover Request Acknowledge 3b. HO Decison 7. RRCConnectionReconfiguration àmobilityControlInfo à radioResourceConfigDedicated à securityConfigHO L3 signaling L1/L2 signaling User data

8.ULInformationTransfer Detach procedure 9.DLInformationTransfer Buffer packets in transmission
Handover Execution

10. SN Status Transfer 11. Data Forwarding Buffer packets from Source eNB 12. Random Access procedure triggered by Handover Peamble Random Access Response Msg3(RRCConnectionReconfigurationComplete)

DL Data UL Data UL Data 13. Path Switch Reqeust
Handover Completion

14. User Plane Update Request 15. End Marker 16. User Plane Update Response 17. Path Swith Request Acknowledge 18. UE Context Release Flush DL buffer and continue forwarding packetes 19. Data Forwarding 20. End Marker Release resource Packet data Packet data

31

Handover Preparation

Measurement

1. RRCConnectionReconfiguration àmeasConfig

TD-LTE 关键过程信令流程解析

Intra-MME/Serving Gateway X2 切换流程的细节描述: 1. 原小区通过 RRCConnectionRefiguration 信令中的 measconfig IE 对 UE 进行测量配置。 其中的 MeasIdToAddMod 将 measId、measObjectId、reportConfigId 联系在一起。 测量上报类型分为周期性上报和事件触发型上报。其中事件触发型上报的分类和意义如下: Event A1: Serving becomes better than absolute threshold; Event A2: Serving becomes worse than absolute threshold; Event A3: Neighbour becomes amount of offset better than serving; Event A4: Neighbour becomes better than absolute threshold; Event A5: Serving becomes worse than absolute threshold1 AND Neighbour becomes better than another absolute threshold2. S-Measure IE 为原小区的质量控制门限,由该 IE 来控制 UE 是否发起测量。 measGapConfig 是原小区为 UE 配置的测量间隔参数。 2. 当原小区的 RSRP 小于 S-Measure IE 所规定的门限,UE 发起对临小区的测量。当测量 结果满足 reportconfig 的配置条件(譬如:A3) ,UE 将测量结果组装在 MeasurementReport 消息中发送给原小区。这样原小区就得到了多个潜在目标小区的测量结果。 3a. 原小区基于测量报告和 RRM 信息来决定是否向多个潜在的目标小区发起切换请求。 4. 原小区发送切换请求消息到目标小区, 携带在目标小区进行切换准备所必需的信息 (切 换 UE 在原小区的 X2 信令相关 context 的标识, UE S1 EPC 信令相关 context 标识, 目标 cell ID,KeNB*,RRC context(包含 UE 在原 eNB 使用的 C-RNTI,AS-configuration(不包含物理 层配置) ,EPS 承载 context 和以备用于无线链路失败恢复的原小区物理层 ID+MAC) ) 。UE X2 / UE S1 信令标识使得目标小区能够找到原小区和 EPC。EPS bearer context 包含必要的 RNL 和 TNL 寻址信息,和 EPS bearer 的 Qos profiles。 5. 如果资原在目标小区被批准,在目标小区基于收到的 EPS bearer Qos 信息执行接入控 制,可以增加切换的成功率。目标小区依照收到的 EPS bearer Qos 信息配置所需的资原并 为切换 UE 保留 C-RNTI,某些情况下,还会为 UE 保留专用的 RACH preamble。要在目标小区 使 用 的 AS-configuration 可 以 被 单 独 指 定 ( “ 建 立 ” ) 或 者 与 原 小 区 使 用 的 AS-configuration 进行对比,使用 Delta 配置(“重配”) 。

32

TD-LTE 关键过程信令流程解析

6. 目标小区配置 L1/L2 准备切换并且发送 HANDOVER REQUEST ACKNOWLEDGE 到原小区。 HANDOVER REQUEST ACKNOWLEDGE 消息包含要被发送到 UE 的透明容器。这个容器是切换命令 的一部分。 容器中包含一个新的 C-RNTI,选择好的目标小区安全算法标识,可能包含专用 的 RACH preamble,专用 RACH preamble 的超时指示器,和其他一些可能的参数,比如接入 参数,SIB 等。如果有必要,HANDOVER REQUEST ACKNOWLEDGE 消息也可能包含为前转隧道准 备的 RNL/TNL。 3b. 原小区在得到多个潜在目标小区关于切换准备的信息后, 执行切换判决算法, 从多个潜 在的目标小区中选择一个最终的目标小区。 7. 原小区生成将发送给 UE 发出切换命令(RRCConnectionRebconfiguration),切换命令 中包含 MobilityControlInfo IE、RadioResourceConfigDedicated IE、SecurityConfigHO IE。这些 IEs 包含一些必要的参数(新的 C-RNTI,目标 eNB 安全性算法标识,可选的专用 RACH preamble,possible expiry time of the dedicated RACH preamble,目标小区的系 统信息等),在原小区命令下执行切换。UE 不需要向原小区发送 HARQ/ARQ 响应即可立即执 行切换。 8-9. UE 收到切换命令后,需要从原小区去附着。 此时,原小区需要将未发送出去的数据和此时发送给 UE 的 buffer 起来。 10. 原小区发送 SN STATUS TRANSFER 消息到目标小区,传送 SAE bearers(仅那些需要保 留 PDCP 状态的 SAE bearer 需要执行 SN 状态的转发)的上行 PDCP SN 接收状态和下行 PDCP SN 发送状态。如果没有 SAE bearer 需要传送 PDCP 的状态报告,原小区可以省略这条消息。 11. 原小区需要将 buffer 起来的数据前转给目标小区。注意:一旦原小区收到了 HANDOVER REQUEST ACKNOWLEDGE, 或者开始下发切换命令,数据前转就可以开始了。 12. UE 与目标小区进行随机接入。这个随机接入是切换触发的随机接入。此过程包含 UE 发 送 preamble,目标小区发送 Random Access Response 给 UE,UE 发送 RRCConnectionReconfigurationComplete。如果在切换命令中配给了专用 RACH preamble, 则使用无竞争随机接入流程接入目标小区,如果没有配给专用的 RACH preamble,则使用基 于竞争随机接入流程接入目标小区。 注意:msg3 中不包含 RRCConnection Request,只包含 RRCConnectionReconfigurationComplete。可见 msg3 只是一个编号,在不同的过程中会有 不同的内容。 13. 目标小区发送 Path Switch Request 消息通知 MME,UE 的所属小区改变了。
33

TD-LTE 关键过程信令流程解析

14. MME 向 Serving Gateway 发送 USER PLANE UPDATE REQUEST 消息。 15. Serving Gateway 将下行数据路径切换到目标小区侧。Serving gateway 在旧路径上发 送一个或多个 "end marker" 包到原小区并且可以释放原小区的 U-plane 资源。 16. Serving Gateway 向 MME 发送 USER PLANE UPDATE RESPONSE 消息。 17. MME 通过发送 PATH SWITCH ACK 消息来确认收到的 PATH SWITCH 消息。 18. 通过发送 UE Context Release 消息,目标小区向原小区通知切换的成功并且触发原小 区的资源释放。目标小区在收到从 MME 发回的 PATH SWITCH ACK 消息以后发送这条消息。 19-20. 收到 UE Context Release 消息并向目标小区发送完 End Marker 以后,原小区可以 释放无线和控制面相关的 UE context 资源。

2、消息解析——对于关键参数进行解析 (1)RRC: MeasurementReport(测量上报) Message type: DCCH_UL Direction: Uplink Frame No: 1008 Subframe No: 7 Computer Timestamp: 17:23:26.734 UL-DCCH-Message message c1 measurementReport criticalExtensions c1 measurementReport-r8 measResults(本区测量结果) measId : 1 measResultServCell rsrpResult : 52 rsrqResult : 15 measResultNeighCells(邻区测量结果) measResultListEUTRA MeasResultEUTRA physCellId : 2 measResult rsrpResult : 61 rsrqResult : 24 (2)RRC: RRCConnectionReconfiguration(切换命令) Message type: DCCH_DL Direction: Downlink
34

TD-LTE 关键过程信令流程解析

Frame No: 1013 Subframe No: 0 Computer Timestamp: 17:23:26.734 DL-DCCH-Message message c1 rrcConnectionReconfiguration rrc-TransactionIdentifier : 0 criticalExtensions c1 rrcConnectionReconfiguration-r8 measConfig measObjectToAddModList MeasObjectToAddMod measObjectId : 1 measObject measObjectEUTRA carrierFreq : 37900(小区中心频 点,按照实际设计配置.目前配置为中心频点为 2585MHz) allowedMeasBandwidth : mbw6 presenceAntennaPort1 : true neighCellConfig : 0x40 offsetFreq : dB0 cellsToAddModList CellsToAddMod cellIndex : 1 physCellId : 2 cellIndividualOffset : dB0 CellsToAddMod cellIndex : 3 physCellId : 1 cellIndividualOffset : dB0 CellsToAddMod cellIndex : 4 physCellId : 4 cellIndividualOffset : dB0 CellsToAddMod cellIndex : 5 physCellId : 5 cellIndividualOffset : dB0
35

TD-LTE 关键过程信令流程解析

reportConfigToAddModList ReportConfigToAddMod reportConfigId : 1 reportConfig reportConfigEUTRA triggerType event eventId eventA3 a3-Offset : 2 (A3 事件触发偏移值,影响切换时两小区间功率差判断,目前配置为 2dB) reportOnLeave : false hysteresis : 4(事件触发 滞后因子,与 a3-Offset 共同影响切换时两小区间功率差判断,目前配置为 2dB) timeToTrigger : ms512 (事 件触发持续时间,目前配置为 512ms) triggerQuantity : rsrp reportQuantity : both maxReportCells : 8(测量上报小区 最大数,目前配置为最大上报 8 个小区) reportInterval : min6(周期上报 间隔,可根据需要随时修改,目前配置为 6 分钟) reportAmount : r1(周期上报次数, 目前配置为 1 次) quantityConfig quantityConfigEUTRA filterCoefficientRSRP : fc4 filterCoefficientRSRQ : fc4 speedStatePars setup mobilityStateParameters t-Evaluation : s120 t-HystNormal : s60 n-CellChangeMedium : 5 n-CellChangeHigh : 10 timeToTrigger-SF sf-Medium : lDot0 sf-High : lDot0 mobilityControlInfo targetPhysCellId : 2 carrierBandwidth dl-Bandwidth : n100 additionalSpectrumEmission : 1
36

TD-LTE 关键过程信令流程解析

t304 : ms2000(收到 RRCConnectionReconfiguration 消息启动,到成功切换终止,目前配置为 2000ms) newUE-Identity : 0x0040 radioResourceConfigCommon rach-ConfigCommon preambleInfo numberOfRA-Preambles : n48 preamblesGroupAConfig sizeOfRA-PreamblesGroupA : n48 messageSizeGroupA : b56 messagePowerOffsetGroupB : dB8 powerRampingParameters powerRampingStep : dB2 preambleInitialReceivedTargetPower : dBm-106(初始接收目标功率,小区激活前可修改,目前配置为-106dBm) ra-SupervisionInfo preambleTransMax : n4(前导码最大传 输次数,目前配置为 4 次) ra-ResponseWindowSize : sf10 mac-ContentionResolutionTimer : sf48 maxHARQ-Msg3Tx : 4 prach-Config rootSequenceIndex : 24(前导码根序列逻辑 索引,当采用 Preamble Format0~3 时,ZC 根序列的选择与当前小区是否为高速小区有关, 当采用 Preamble Format0~3 且为高速小区时,RootSeqIndex 的取值与 Ncs 有关,Preamble 格式影响 RootSeqIndex 的取值范围以及选择原则) prach-ConfigInfo prach-ConfigIndex : 3 highSpeedFlag : false zeroCorrelationZoneConfig : 3 prach-FreqOffset : 17(PRACH 频域偏 移,避开 PUCCH 占用的资源,参数取值可以取 PrachFreqOffset=向上取整(每个时隙内所有 PUCCH 占用的资源块数 /2) ,目前每个时隙内所有 PUCCH 占用的资源块数取值为 33,则 PrachFreqOffset 取值为 17。 ) pdsch-ConfigCommon referenceSignalPower : 15(小区参考信号 功率,15 对应全带宽等效总功率 45.79dBm) p-b : 1(无 CRS 的 OFDM 符号上的数据 RE 与 有 CRS 的 OFDM 符号上数据 RE 的能量之比,一般取 1,即功率比为 1:1) pusch-ConfigCommon pusch-ConfigBasic n-SB : 4 hoppingMode : interSubFrame pusch-HoppingOffset : 33(PUSCH 跳频
37

TD-LTE 关键过程信令流程解析

偏移,目前配置为 33) enable64QAM : true ul-ReferenceSignalsPUSCH groupHoppingEnabled : false groupAssignmentPUSCH : 0 sequenceHoppingEnabled : false cyclicShift : 0 phich-Config phich-Duration : normal phich-Resource : half pucch-ConfigCommon deltaPUCCH-Shift : ds2 nRB-CQI : 2 nCS-AN : 0 n1PUCCH-AN : 36 soundingRS-UL-ConfigCommon setup srs-BandwidthConfig : bw0 srs-SubframeConfig : sc0 ackNackSRS-SimultaneousTransmission : true srs-MaxUpPts : true(最大带宽重配指 示,指示是否允许重配置 UpPts 的参数,布尔值,取值 true 表示,false 表示不允许) uplinkPowerControlCommon p0-NominalPUSCH : -85(持续调度期望接收 功率,持续调度 PUSCH 期望接收功率,取值(-126..24)dBm,颗粒度为 1dB,可根据需要调 整) alpha : al1 p0-NominalPUCCH : -112 deltaFList-PUCCH deltaF-PUCCH-Format1 : deltaF0 deltaF-PUCCH-Format1b : deltaF1 deltaF-PUCCH-Format2 : deltaF0 deltaF-PUCCH-Format2a : deltaF2 deltaF-PUCCH-Format2b : deltaF2 deltaPreambleMsg3 : 4 antennaInfoCommon antennaPortsCount : an2 p-Max : 23 tdd-Config subframeAssignment : sa1 specialSubframePatterns : ssp7 ul-CyclicPrefixLength : len1 rach-ConfigDedicated
38

TD-LTE 关键过程信令流程解析

ra-PreambleIndex : 48 ra-PRACH-MaskIndex : 0 radioResourceConfigDedicated srb-ToAddModList SRB-ToAddMod srb-Identity : 1 rlc-Config explicitValue am ul-AM-RLC t-PollRetransmit : ms200 pollPDU : p64 pollByte : kB100 maxRetxThreshold : t6 dl-AM-RLC t-Reordering : ms50 t-StatusProhibit : ms0 logicalChannelConfig explicitValue ul-SpecificParameters priority : 1 prioritisedBitRate : infinity bucketSizeDuration : ms50 logicalChannelGroup : 0 SRB-ToAddMod srb-Identity : 2 rlc-Config explicitValue am ul-AM-RLC t-PollRetransmit : ms200 pollPDU : p64 pollByte : kB100 maxRetxThreshold : t6 dl-AM-RLC t-Reordering : ms50 t-StatusProhibit : ms0 logicalChannelConfig explicitValue ul-SpecificParameters priority : 3 prioritisedBitRate : infinity
39

TD-LTE 关键过程信令流程解析

bucketSizeDuration : ms50 logicalChannelGroup : 0 drb-ToAddModList DRB-ToAddMod drb-Identity : 3 pdcp-Config headerCompression : notUsed rlc-Config um-Bi-Directional ul-UM-RLC sn-FieldLength : size10 dl-UM-RLC sn-FieldLength : size10 t-Reordering : ms50 logicalChannelConfig ul-SpecificParameters priority : 11 prioritisedBitRate : kBps8 bucketSizeDuration : ms100 logicalChannelGroup : 3 mac-MainConfig explicitValue ul-SCH-Config maxHARQ-Tx : n4(上行最大传输次数, 目前配置为 4 次) periodicBSR-Timer : sf5 retxBSR-Timer : sf320 ttiBundling : false timeAlignmentTimerDedicated : infinity phr-Config setup periodicPHR-Timer : sf1000 prohibitPHR-Timer : sf200 dl-PathlossChange : dB3 physicalConfigDedicated pdsch-ConfigDedicated p-a : dB-3 pucch-ConfigDedicated ackNackRepetition : release tdd-AckNackFeedbackMode : bundling pusch-ConfigDedicated betaOffset-ACK-Index : 9 betaOffset-RI-Index : 10 betaOffset-CQI-Index : 13
40

TD-LTE 关键过程信令流程解析

uplinkPowerControlDedicated p0-UE-PUSCH : 0 deltaMCS-Enabled : en0 accumulationEnabled : false p0-UE-PUCCH : 0 pSRS-Offset : 5 filterCoefficient : fc4 cqi-ReportConfig nomPDSCH-RS-EPRE-Offset : 0 cqi-ReportPeriodic setup cqi-PUCCH-ResourceIndex : 0 cqi-pmi-ConfigIndex : 18 cqi-FormatIndicatorPeriodic widebandCQI

:

ri-ConfigIndex : 322 simultaneousAckNackAndCQI : true soundingRS-UL-ConfigDedicated setup srs-Bandwidth : bw0 srs-HoppingBandwidth : hbw0 freqDomainPosition : 0 duration : true srs-ConfigIndex : 25 transmissionComb : 0 cyclicShift : cs0 antennaInfo explicitValue transmissionMode : tm3 codebookSubsetRestriction n2TxAntenna-tm3 : 0xC0 ue-TransmitAntennaSelection : release schedulingRequestConfig setup sr-PUCCH-ResourceIndex : 0 sr-ConfigIndex : 3 dsr-TransMax : n32 (DSR 最大传输次数, 专用调度请求最大传输次数,按照枚举取值{n4, n8, n16, n32, n64},其中 n4 对应 4 次传 输,目前配置为 32 次) securityConfigHO handoverType intraLTE keyChangeIndicator : false
41

TD-LTE 关键过程信令流程解析

nextHopChainingCount : 0 (3)MasterInformationBlock、SysInfoType1、SysInfo:主信息、系统信息消息,用于 Ue 驻留到服务小区,Ue 接入目标小区过程同前附着中读取系统系统信息过程解析。 (4)RRC: RRCConnectionReconfigurationComplete(Ue 发送 RRC 连接重配置完成消息, 向目标 ENB 确认切换过程完成) Message type: DCCH_UL Direction: Uplink Frame No: 1015 Subframe No: 9 Computer Timestamp: 17:23:26.734 UL-DCCH-Message message c1 rrcConnectionReconfigurationComplete rrc-TransactionIdentifier : 0 criticalExtensions : rrcConnectionReconfigurationComplete-r8

42


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