LTE RRC Messages

LTE RRC messages cover system information, connection setup, reconfiguration, security mode, paging, measurements, UE capability exchange, and handover signaling between the UE and eNodeB.

Use this LTE RRC message library to browse reference pages for MasterInformationBlock, System Information, SIB messages, RRCConnection procedures, Security Mode messages, Measurement Report, Paging, and other E-UTRA radio control signaling defined in 3GPP TS 36.331.

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All Messages in This Category

This is the full published list for the LTE RRC category. Use the filter section above for a narrower interactive view.

LTE RRC LTE

LTE RRC Connection Reconfiguration

Downlink LTE RRC message used to modify radio configuration, measurements, mobility behavior, bearer settings, and connected-mode control after setup.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC Connection Reconfiguration Complete

Uplink LTE RRC message sent by the UE to confirm successful handling of RRCConnectionReconfiguration.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC Connection Reestablishment

Downlink LTE RRC message sent by the network to accept re-establishment and rebuild the connected signaling context after a recoverable failure.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC Connection Reestablishment Complete

Uplink LTE RRC message sent by the UE to confirm that re-establishment recovery was completed successfully.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC Connection Reestablishment Reject

Downlink LTE RRC message sent by the network when the re-establishment attempt is not accepted.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC Connection Reestablishment Request

Uplink LTE RRC message sent by the UE to request re-establishment after radio link failure, handover failure, or other re-establishment-eligible failure conditions.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC Connection Reject

Downlink LTE RRC message sent by the eNodeB when a fresh RRC connection establishment attempt is not accepted.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC Connection Release

Downlink LTE RRC message used to release the connected RRC context and move the UE back toward idle-mode behavior or redirection handling.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC Connection Request

Uplink LTE RRC message sent by the UE on SRB0 and UL-CCCH to request establishment of an RRC connection.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC Connection Resume Complete-r13

Uplink LTE RRC message sent by the UE to confirm that the resume branch completed successfully and the suspended context was restored.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC Connection Resume Request-r13

Uplink LTE RRC message sent by the UE to request continuation of a suspended LTE context without starting a full fresh connection setup.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC Connection Resume-r13

Downlink LTE RRC message sent by the eNodeB to resume a suspended LTE connection context without starting a full fresh connection setup.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC Connection Setup

Downlink LTE RRC message sent by the eNodeB to establish SRB1 and move the UE into connected-mode signaling.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC Connection Setup Complete

Uplink LTE RRC message sent by the UE after applying RRCConnectionSetup to confirm setup completion and carry the initial dedicated NAS message.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC Counter Check

Downlink LTE RRC message used by the eNodeB to ask the UE to verify PDCP COUNT synchronization for one or more DRBs.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC Counter Check Response

Uplink LTE RRC message used by the UE to reply to Counter Check and confirm the outcome of the PDCP COUNT verification step.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC CSFB Parameters Request CDMA2000

Downlink LTE RRC message used to request cdma2000-related CS fallback parameter handling from the UE.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC CSFB Parameters Response CDMA2000

Uplink LTE RRC message used by the UE to return cdma2000 CS fallback parameters requested by the network.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC DL Dedicated Message Segment-r16

Downlink LTE RRC segmentation container used when a dedicated LTE RRC message is split across multiple fragments.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC DL Information Transfer

Downlink LTE RRC message used by the eNodeB to carry NAS payloads toward the UE over the LTE access stratum.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC Early Data Complete-r15

Downlink LTE RRC message used to complete the control-plane early data transmission branch.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC Early Data Request-r15

Uplink LTE RRC message used by the UE to request control-plane early data transmission.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC Failure Information r15

Uplink LTE RRC message used by the UE to report release-specific failure information back to the network.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC Failure Information r16

Uplink LTE RRC message used by the UE to return release 16 failure information to the network.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC Handover From EUTRA Preparation Request

Downlink LTE RRC message used when the source E-UTRA side starts handover preparation toward cdma2000.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC InDeviceCoex Indication r11

Uplink LTE RRC message used by the UE to report in-device coexistence constraints that affect LTE radio operation.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC InterFreqRSTD Measurement Indication r10

Uplink LTE RRC message used by the UE to indicate status around inter-frequency RSTD measurement handling for positioning-related procedures.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC Logged Measurement Configuration-r10

Downlink LTE RRC message used to configure logged measurement collection for MDT-related behavior.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC MBMS Counting Request r10

Downlink LTE RRC message used by the network to request MBMS counting responses from interested UEs.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC MBMS Counting Response r10

Uplink LTE RRC message used by the UE to answer an MBMS counting request.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC MBMS Interest Indication r11

Uplink LTE RRC message used by the UE to report MBMS interest information to the network.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC MBSFN Area Configuration r9

Downlink LTE RRC message used to deliver MBSFN area configuration to the UE.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC MCG Failure Information r16

Uplink LTE RRC message used by the UE to report master cell group failure information.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC MeasReportAppLayer r15

Uplink LTE RRC message used by the UE to report configured application-layer measurement results to the network.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC Measurement Report

Uplink LTE RRC message sent by the UE when configured measurement conditions are met so the network can make mobility and radio-control decisions.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC MIB - Master Information Block

Broadcast LTE RRC message on BCH that gives the UE the first essential cell-wide radio context needed to continue system-information acquisition toward SIB1 and later access behavior.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC MIB MBMS r14

Broadcast LTE RRC message carrying the MBMS-specific master information block for MBMS-oriented operation.

Broadcast 3GPP TS 36.331
LTE RRC LTE

LTE RRC Mobility From EUTRA Command

Downlink LTE RRC message used to command mobility away from the current E-UTRA connection toward another RAT or a cell change order outcome.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC Paging

Downlink LTE RRC message used to notify an idle UE that the network needs its attention for service, signaling, system information change, or warning-related behavior.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC Proximity Indication r9

Uplink LTE RRC message used by the UE to report proximity-related status relevant to network-controlled proximity services handling.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC PUR Configuration Request r16

Downlink LTE RRC message used to request or deliver PUR-related configuration handling.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC RN Reconfiguration Complete-r10

Uplink LTE RRC message used by the relay node to acknowledge RNReconfiguration-r10.

RN -> Donor eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC RN Reconfiguration-r10

Downlink LTE RRC message used by a donor eNodeB to change relay-node specific configuration.

Donor eNodeB -> RN 3GPP TS 36.331
LTE RRC LTE

LTE RRC SCG Failure Information NR r15

Uplink LTE RRC message used in E-UTRA master / NR secondary contexts when the UE reports failure affecting the NR-side secondary cell group.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC SCG Failure Information r12

Uplink LTE RRC message used by the UE to report secondary cell group failure in dual-connectivity related LTE contexts.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC SCPTM Configuration BR r14

Downlink LTE RRC message used to deliver SC-PTM configuration for bandwidth-reduced UE contexts.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC SCPTM Configuration r13

Downlink LTE RRC message used to deliver SC-PTM configuration to the UE.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC Security Mode Command

Downlink LTE RRC message sent by the eNodeB to activate access-stratum security for the UE.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC Security Mode Complete

Uplink LTE RRC message sent by the UE to confirm that SecurityModeCommand was accepted and LTE AS security activation succeeded.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC Security Mode Failure

Uplink LTE RRC message sent by the UE when it cannot continue with the received SecurityModeCommand.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC SIB1 - System Information Block Type 1

Broadcast LTE RRC message on BCCH and DL-SCH that gives the UE the essential access identity, cell selection, scheduling, and change-detection context needed before it can use the wider SIB set.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC SIB1 BR r13

Broadcast LTE RRC message carrying the first BR-specific system-information block.

Broadcast 3GPP TS 36.331
LTE RRC LTE

LTE RRC SIB1 MBMS r14

Broadcast LTE RRC message carrying the first MBMS-specific system-information block.

Broadcast 3GPP TS 36.331
LTE RRC LTE

LTE RRC SIB13 - System Information Block Type 13

Broadcast LTE RRC system information block carried inside System Information that provides MBMS and MBSFN area information used before MCCH reception.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC SIB2 - System Information Block Type 2

Broadcast LTE RRC system information block carried inside System Information that gives the UE the common radio, access barring, timer, and uplink-related context needed before normal LTE access can proceed.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC SIB3 - System Information Block Type 3

Broadcast LTE RRC system information block carried inside System Information that gives the UE the serving-frequency cell reselection rules used in idle mode after the common SIB1 and SIB2 context is already known.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC SIB4 - System Information Block Type 4

Broadcast LTE RRC system information block carried inside System Information that provides intra-frequency neighbor-cell detail used during idle-mode camping and same-frequency cell reselection.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC SIB5 - System Information Block Type 5

Broadcast LTE RRC system information block carried inside System Information that provides inter-frequency reselection information for other LTE carrier frequencies in idle mode.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC SIB6 - System Information Block Type 6

Broadcast LTE RRC system information block carried inside System Information that provides inter-RAT reselection information for UTRA frequencies and UTRA neighboring cells in idle mode.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC SIB7 - System Information Block Type 7

Broadcast LTE RRC system information block carried inside System Information that provides inter-RAT reselection information for GERAN frequencies in idle mode.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC SIB8 - System Information Block Type 8

Broadcast LTE RRC system information block carried inside System Information that provides inter-RAT reselection information for cdma2000 1xRTT and HRPD idle mobility.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC Sidelink UE Information r12

Uplink LTE RRC message used by the UE to report sidelink-related information to the network.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC System Information

Broadcast LTE RRC message on BCCH and DL-SCH that carries one or more SIBs such as SIB2 and later system-information blocks after the UE has already read MIB and SIB1.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC System Information BR r13

Broadcast LTE RRC message carrying bandwidth-reduced system information.

Broadcast 3GPP TS 36.331
LTE RRC LTE

LTE RRC System Information MBMS r14

Broadcast LTE RRC message carrying later MBMS-specific system information.

Broadcast 3GPP TS 36.331
LTE RRC LTE

LTE RRC UE Assistance Information r11

Uplink LTE RRC message used by the UE to provide assistance information the network can use for connected-mode optimization decisions.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC UE Capability Enquiry

Downlink LTE RRC message used by the eNodeB to request UE capability information before applying capability-dependent radio configuration.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC UE Capability Information

Uplink LTE RRC message used by the UE to report its capability information back to the eNodeB.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC UE Information Request r9

Downlink LTE RRC message used by the eNodeB to ask the UE for stored diagnostic information such as random access details or radio link failure context.

eNodeB -> UE 3GPP TS 36.331
LTE RRC LTE

LTE RRC UE Information Response r9

Uplink LTE RRC message used by the UE to return the diagnostic information requested by UEInformationRequest-r9, including random access details, radio link failure context, or both.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC UL Dedicated Message Segment-r16

Uplink LTE RRC segmentation container used when a UE dedicated LTE RRC message is sent in multiple fragments.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC UL Handover Preparation Transfer

Uplink LTE RRC message used by the UE to return cdma2000 handover preparation information to the source eNodeB.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC UL Information Transfer

Uplink LTE RRC message used by the UE to carry NAS payloads toward the network over the LTE access stratum.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC UL Information Transfer IRAT r16

Uplink LTE RRC message used to transfer dedicated information in inter-RAT related contexts.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC UL Information Transfer MRDC r15

Uplink LTE RRC message used to transfer dedicated information in MR-DC related contexts.

UE -> eNodeB 3GPP TS 36.331
LTE RRC LTE

LTE RRC WLAN Connection Status Report r13

Uplink LTE RRC message used by the UE to report WLAN connection status relevant to LTE and WLAN interworking handling.

UE -> eNodeB 3GPP TS 36.331

Related Procedures