Search the 3GPP Message Database

5GSM Status is the 5GSM message used by both the UE and the network to report protocol errors or invalid session-management conditions for an active PDU session.

Authentication Failure is the UE's NAS message indicating that it could not validate or complete the network authentication challenge.

Authentication Reject is the NAS message the network sends when the UE's authentication attempt is not accepted and the current 5GMM path must stop.

Authentication Request is the NAS message the AMF uses to challenge the UE and start the 5G primary authentication procedure.

Authentication Response is the UE's NAS reply to Authentication Request, carrying the computed response or EAP data needed for subscriber verification.

Authentication Result is the NAS message used to transport the final EAP authentication result from the network to the UE.

Configuration Update Command is the network-initiated NAS message used to update UE 5GMM context after registration.

Configuration Update Complete is the UE's NAS acknowledgement that a network-initiated configuration update was received and applied.

Control Plane Service Request is the NAS message used when the UE requests control-plane service handling without the normal user-plane service path.

Deregistration Accept (UE Originating) is the AMF response confirming that the UE-originated deregistration request was accepted.

Deregistration Accept (UE Terminated) is the UE response confirming that a network-initiated deregistration request was received and accepted.

Deregistration Request (UE Originating) is the NAS message the UE sends when it wants to deregister from the 5GS.

Deregistration Request (UE Terminated) is the AMF-to-UE NAS message used when the network initiates deregistration.

DL NAS Transport is the NAS wrapper message the network uses to deliver a payload downward to the UE when the procedure needs to carry additional content transparently through NAS.

Identity Request is the NAS message the network sends when it needs the UE to provide a specific identity such as SUCI, 5G-GUTI-related context, IMEI, IMEISV, or other identity information.

Identity Response is the NAS message the UE sends after Identity Request to provide the specific identity type the network asked for, such as SUCI, IMEI, IMEISV, or another requested identifier.

Network Slice-Specific Authentication Command is the NAS message the network uses to start slice-specific authentication for a requested S-NSSAI.

Network Slice-Specific Authentication Complete is the UE's response carrying the slice-specific authentication reply for the requested S-NSSAI.

Network Slice-Specific Authentication Result is the NAS message carrying the final outcome of slice-specific authentication for a requested S-NSSAI.

Notification is the NAS message the network sends to inform the UE about an event that requires the UE's attention in the current mobility-management context.

Notification Response is the NAS message the UE sends after receiving Notification from the network to acknowledge the NAS indication and let the protected procedure continue.

PDU Session Authentication Command is the 5GSM message that carries an EAP request from the SMF to the UE when session-level authentication or authorization is required.

PDU Session Authentication Complete is the 5GSM message the UE sends in response to PDU Session Authentication Command to carry the EAP response and continue the session-authentication exchange.

PDU Session Authentication Result is the 5GSM message the SMF sends to indicate a successful outcome of PDU session authentication, and it can also carry an EAP-success when external DN authentication is used.

PDU Session Establishment Accept is the 5GSM success message the network sends after it creates the requested PDU session and returns the final session parameters, address, and QoS context.

PDU Session Establishment Reject is the 5GSM failure response the network sends when the requested PDU session cannot be created and the UE needs the rejection reason.

PDU Session Establishment Request is the 5GSM message the UE sends to request creation of a new PDU session for user-plane connectivity toward a DNN on a selected slice.

PDU Session Modification Command is the 5GSM message the network sends to tell the UE how an active PDU session should be updated after the modification request is accepted or when the network itself is changing the session.

PDU Session Modification Command Reject is the 5GSM message the UE sends when it cannot accept the network's modification command for an active PDU session.

PDU Session Modification Complete is the 5GSM message the UE sends after it applies the network-approved changes to an active PDU session.

PDU Session Modification Reject is the 5GSM failure response the network sends when a UE-requested change to an active PDU session cannot be accepted.

PDU Session Modification Request is the 5GSM message the UE sends to change an already active PDU session, such as updating QoS, packet-filter behavior, header-compression settings, or other session parameters.

PDU Session Release Command is the 5GSM message the network sends to tell the UE that an active PDU session is being released and to provide any release-related cause or retry guidance.

PDU Session Release Complete is the 5GSM message the UE sends after it receives a release command and considers the active PDU session released.

PDU Session Release Reject is the 5GSM failure response the network sends when it does not accept the UE's request to release an active PDU session.

PDU Session Release Request is the 5GSM message the UE sends when it wants to end an already active PDU session, or when it needs to release the session because of a local protocol or service condition.

Registration Accept is the 5GMM message the AMF sends when it accepts UE registration and returns the mobility, security, and reachability context the UE needs to operate in the 5GS.

Registration Complete is the UE-to-AMF NAS message used to confirm that the UE has accepted the registration context returned by the network.

Registration Reject is the NAS message the AMF sends when a 5G registration attempt is refused and the UE must stop the current registration path.

Starts a 5G registration or mobility update by sending UE identity and registration intent to the core.

Relay Authentication Request is the NAS message the network sends to start or continue the relay-specific authentication branch after relay-key handling or related relay security preparation.

Relay Authentication Response is the NAS message the UE or relay participant sends back after Relay Authentication Request to return the relay-specific authentication result information.

Relay Key Accept is the NAS message the network sends when the relay key request succeeds and the relay-related key response material can be delivered to the UE.

Relay Key Reject is the NAS message the network sends when the relay key request cannot be accepted and the relay-related key procedure must stop or take a failure branch.

Relay Key Request is the NAS message used to request relay-related keying material so the relay security procedure can continue in a 5G relay or ProSe relay context.

Remote UE Report is the 5GSM message the relay UE sends to inform the network that one or more 5G ProSe remote UEs connected or disconnected through the relay.

Remote UE Report Response is the 5GSM acknowledgement sent back to the relay UE after the SMF processes a Remote UE Report.

Security Mode Command is the NAS message the AMF sends to activate the selected NAS security algorithms and move the 5GMM procedure into a protected signaling state.

Security Mode Complete is the NAS message the UE sends to confirm that it accepted the selected NAS security algorithms and has switched into the commanded protected signaling state.

Security Mode Reject is the NAS message the UE sends when it cannot accept the NAS security configuration selected by the AMF in Security Mode Command.

Service Accept is the NAS message confirming that the network accepted the UE's service request and that active service can continue.

Service Reject is the NAS message the network sends when a service request is refused even though the UE already has registration context.

Service Request is the NAS message the UE uses to request service resumption when it already has a valid registration context but needs active signaling again.

Service-level Authentication Command is the 5GSM message the SMF sends to deliver service-level authentication and authorization payload to the UE.

Service-level Authentication Complete is the 5GSM message the UE sends in response to Service-level Authentication Command and uses to return the service-level AA payload or response.

UL NAS Transport is the NAS wrapper message the UE uses to send a payload upward toward the core when the NAS procedure needs to carry additional information transparently.

Counter Check is the NR RRC message the network uses to provide current PDCP COUNT MSB values for configured DRBs and ask the UE to compare them with its own COUNT state.

Counter Check Response is the NR RRC message the UE sends after Counter Check to return the compared DRB COUNT values for bearer-state verification.

Dedicated SIB Request is the UE-to-network NR RRC message used to request on-demand system information while the UE is already in connected mode.

DL Dedicated Message Segment is the NR downlink RRC segmentation container used when a dedicated RRC message is too large to send as a single unit.

DL Information Transfer is the NR RRC message the network uses to send upper-layer information, most commonly NAS messages, to the UE over the established RRC connection.

DL Information Transfer MRDC is the downlink NR RRC container used to deliver MR-DC-related information toward the UE.

Failure Information is the NR RRC message the UE uses to inform the network that it has detected a failure, especially an RLC bearer failure associated with an MCG or SCG bearer.

IAB Other Information is an NR RRC message used to deliver additional IAB-specific information needed by an IAB node.

Indirect Path Failure Information is an NR RRC message used to report failure related to an indirect path or relayed path in advanced deployment scenarios.

NGAP initiating message used by the NG-RAN to transfer the UE's first uplink NAS message to the AMF.

Location Measurement Indication is the NR RRC message used by the UE to indicate location-related measurement information toward the network.

Logged Measurement Configuration is the NR RRC message used to configure measurement logging behavior for MDT and later reporting workflows.

The NR Master Information Block (MIB) is the first essential broadcast RRC information a UE decodes from PBCH after synchronization. It gives the UE the minimal system information needed to continue toward SIB1 acquisition and initial access.

MBS Broadcast Configuration is the NR RRC message used to provide UE-specific or dedicated MBS broadcast configuration.

MBS Interest Indication is the UE-to-network NR RRC message used to indicate interest in MBS services or sessions.

MBS Multicast Configuration is the NR RRC message used to provide dedicated MBS multicast configuration to the UE.

MCG Failure Information is the NR RRC message used by the UE to report failure related to the master cell group.

Measurement Configuration is the NR RRC configuration block that tells the UE what to measure, when to report, and how measurement identities map objects and report rules. It is usually delivered inside RRC Reconfiguration rather than as a standalone message.

Measurement Report is the NR RRC message a UE sends to the gNB when configured measurement conditions are met, allowing the network to make mobility, beam, and radio-resource decisions.

Measurement Report AppLayer is the NR RRC message used by the UE to report application-layer measurements to the network.

Mobility From NR Command is the NR RRC message used by the network to command mobility away from the current NR context toward another target system or mobility outcome.

Paging is the NR RRC message used by the network to notify an idle-mode or inactive-mode UE that downlink signaling or service activity requires the UE's attention.

Reconfigures the UE radio connection after setup, including bearers, measurements, and mobility.

RRC Reconfiguration Complete is the UE-to-network NR RRC message confirming that the UE successfully applied the received RRC Reconfiguration.

RRC Reestablishment is the downlink NR RRC message the network sends when it accepts a reestablishment attempt and provides the recovered connected-mode context.

RRC Reestablishment Complete is the UE-to-network NR RRC message confirming that reestablishment succeeded and the recovered context is active.

Uplink NR RRC message sent by the UE on SRB0 and CCCH to request re-establishment of an existing RRC connection after radio link failure, handover failure, or reconfiguration failure.

Downlink NR RRC message used by the network to reject an RRC connection establishment attempt or an RRC connection resumption attempt.

RRC Release is the downlink NR RRC message used by the network to release the connected-mode context and move the UE out of active connected signaling.

RRC Resume is the downlink NR RRC message used by the network to resume a suspended or inactive context after a valid resume request.

RRC Resume Complete is the UE-to-network NR RRC message confirming that the suspended or inactive context was resumed successfully.

RRC Resume Request is the UE-to-network NR RRC message used to request resumption of a suspended or inactive context.

RRC Resume Request1 is an alternate NR RRC resume request message variant used in the resume procedure.

Downlink NR RRC message sent by the gNB to establish SRB1 and move the UE into the connected RRC procedure.

Uplink NR RRC message sent by the UE on SRB1 and DCCH to confirm successful RRC connection establishment and transfer the initial NAS message.

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

RRC SystemInfo Request is the NR RRC message the UE uses to request system information directly from the network.

SCG Failure Information is the NR RRC message used by the UE to report failure related to the secondary cell group.

SCG Failure Information EUTRA is the NR RRC message used to report failure in an E-UTRA secondary cell group context.

Downlink NR RRC message used by the gNB to activate AS security for the UE in RRC_CONNECTED.

Uplink NR RRC message used by the UE to confirm successful activation of the selected AS security configuration.

Uplink NR RRC message used by the UE to indicate that the commanded AS security activation could not be completed successfully.

Sidelink UE Information NR is the UE-to-network NR RRC message used to provide sidelink-related information toward the network.

System Information is the NR RRC broadcast container used to carry one or more SIBs or positioning SIBs with the same periodicity.

SystemInformationBlockType1 (SIB1) is the key NR broadcast system information block that tells the UE how to access the cell, select PLMN context, and interpret important cell-level access restrictions and configuration.

System Information Block 10 (SIB10) is an NR broadcast system information block used to carry the Human-Readable Network Names (HRNN) of NPNs listed in SIB1.

System Information Block 11 (SIB11) is an NR broadcast system information block used to provide idle and inactive measurement configuration for the UE.

System Information Block 12 (SIB12) is an NR broadcast system information block used to provide sidelink communication and discovery configuration to UEs that support NR sidelink.

System Information Block 13 (SIB13) is an NR broadcast system information block used to provide V2X sidelink communication information aligned with the LTE SystemInformationBlockType21 behavior referenced by NR.

System Information Block 14 (SIB14) is an NR broadcast system information block used to provide information related to LTE SystemInformationBlockType26 for V2X sidelink communication.

System Information Block 15 (SIB15) is an NR broadcast system information block used to provide disaster roaming information for PLMNs sharing the cell.

System Information Block 16 (SIB16) is an NR broadcast system information block used to provide slice-based cell reselection information.

System Information Block 17 (SIB17) is an NR broadcast system information block used to provide TRS resource configuration for idle and inactive UEs.

System Information Block 18 (SIB18) is an NR broadcast system information block used to provide Group IDs for Network selection (GINs) to support credentials-holder based access and UE onboarding.

System Information Block 19 (SIB19) is an NR broadcast system information block used to provide NTN-specific parameters for the serving cell and, when present, neighboring NTN cells.

System Information Block 2 (SIB2) is an NR broadcast system information block used mainly for cell reselection and idle-state mobility-related behavior after the UE has already acquired the essential access information from MIB and SIB1.

System Information Block 20 (SIB20) is an NR broadcast system information block used to provide the MCCH and MTCH acquisition configuration for MBS broadcast.

System Information Block 21 (SIB21) is an NR broadcast system information block used to provide MBS Frequency Selection Area Identity mapping for service continuity.

System Information Block 22 (SIB22) is an NR broadcast system information block used to provide ATG-specific parameters for the serving cell and optionally neighboring cells.

System Information Block 23 (SIB23) is an NR broadcast system information block used to provide ranging and sidelink positioning information.

System Information Block 24 (SIB24) is an NR broadcast system information block used to provide the information required to acquire multicast MCCH and MTCH configuration.

System Information Block 25 (SIB25) is an NR broadcast system information block used to provide TN coverage information for NTN-related operation.

System Information Block 3 (SIB3) is an NR broadcast system information block used for intra-frequency cell reselection behavior and idle-state mobility decisions on the current NR carrier.

System Information Block 4 (SIB4) is an NR broadcast system information block used for inter-frequency cell reselection behavior and idle-state mobility decisions across other NR carrier frequencies.

System Information Block 5 (SIB5) is an NR broadcast system information block used for inter-RAT mobility context, helping the UE evaluate reselection toward other radio access technologies such as LTE.

System Information Block 6 (SIB6) is an NR broadcast system information block used for inter-RAT mobility context toward UTRA, helping the UE evaluate reselection from NR toward UMTS when that mobility path is part of the deployment.

System Information Block 7 (SIB7) is an NR broadcast system information block used for inter-RAT mobility context toward GERAN, helping the UE evaluate reselection from NR toward GSM where that legacy mobility path still exists.

System Information Block 8 (SIB8) is an NR broadcast system information block used for inter-RAT mobility context toward cdma2000 systems where that legacy mobility path still exists.

System Information Block 9 (SIB9) is an NR broadcast system information block used to convey time information such as UTC and GPS-related timing context to the UE.

UE Assistance Information is the UE-to-network NR RRC message used to provide assistance or preference information that helps the network optimize handling for the UE.

Downlink NR RRC message used by the gNB to request UE capability information needed for feature, bearer, mobility, and radio configuration decisions.

Uplink NR RRC message used by the UE to report its supported radio capability containers to the gNB.

UE Information Request is the NR RRC message the network uses to ask the UE for diagnostic information such as radio link failure context, connection establishment failure context, logged measurements, mobility history, random access reports, or idle and inactive measurement information.

UE Information Response is the NR RRC message the UE uses to return requested diagnostic information such as RLF data, connection establishment failure data, logged measurements, mobility history, random access reports, or idle and inactive measurement information.

UE Positioning Assistance Info is the UE-to-network NR RRC message used to provide UE-side positioning assistance information.

UL Dedicated Message Segment is the uplink NR RRC segmentation container used when a UE dedicated RRC payload is too large to send as a single message.

UL Information Transfer is the NR RRC message the UE uses to send upper-layer information, most commonly NAS messages, to the network over the established RRC connection.

UL Information Transfer IRAT is the UE-to-network NR RRC wrapper used to carry inter-RAT related information in the uplink direction.

UL Information Transfer MRDC is the UE-to-network NR RRC wrapper used to carry MR-DC-related information in the uplink direction.

100 Trying confirms that the request was received and transaction processing has started.

180 Ringing shows that the terminating side is being alerted for the session request.

181 Call Is Being Forwarded shows that the original target is redirecting or forwarding the session attempt.

182 Queued shows that the request is waiting in a queue instead of progressing immediately.

183 Session Progress shows that the session is advancing before final answer and often carries early-session SDP.

200 OK confirms that the SIP request completed successfully.

202 Accepted means the request was accepted for further handling, but the full outcome will be reported later.

302 Moved Temporarily redirects the sender to another temporary target or contact.

380 Alternative Service indicates that the original request cannot be served as asked and suggests another service path.

400 Bad Request means the request could not be understood or accepted because of syntax or structural problems.

401 Unauthorized challenges the request and asks the sender to retry with authentication.

403 Forbidden means the request was understood but the network or service refused to allow it.

404 Not Found means the target user or service could not be found at the requested destination.

405 Method Not Allowed means the target exists but does not allow the SIP method that was used.

406 Not Acceptable means the request was understood, but the target cannot satisfy the acceptable formats or features indicated.

407 Proxy Authentication Required challenges the sender to authenticate through a SIP proxy, commonly the P-CSCF path.

408 Request Timeout means the expected transaction progress did not happen in time.

415 Unsupported Media Type means the target cannot process the request body in the format that was sent.

480 Temporarily Unavailable means the target is currently unreachable or unavailable, but not permanently unknown.

481 Call or Transaction Does Not Exist means the receiving side could not match the request to a valid dialog or transaction.

486 Busy Here means the target user is busy at the reached destination.

487 Request Terminated means the original request branch was stopped before normal completion.

488 Not Acceptable Here means the request reached the target, but the local media or session offer cannot be accepted there.

500 Server Internal Error means the server hit an internal problem while handling the request.

503 Service Unavailable means the service cannot handle the request right now, usually for temporary server or overload reasons.

504 Server Time-out means a server did not get a timely answer from another server while handling the request.

600 Busy Everywhere means the request should not be retried elsewhere because the target is considered busy globally.

603 Decline means the request was actively refused and should not be retried to other locations for the same attempt.

604 Does Not Exist Anywhere means the target does not exist globally for the request.

606 Not Acceptable means no acceptable target branch can satisfy the requested session or content constraints.

608 Rejected means the request was rejected without exposing the more specific target-state reason.

ACK is the SIP request that confirms a final response to INVITE.

BYE is the SIP request that terminates an established dialog.

CANCEL is the SIP request that stops a pending INVITE transaction before final acceptance.

INFO is the SIP request used to carry mid-session information inside an existing dialog.

INVITE is the SIP request that starts or modifies the main session dialog in IMS.

MESSAGE is the SIP request used to carry standalone message content without creating a full session dialog.

NOTIFY is the SIP request that delivers state updates for an active subscription.

OPTIONS is the SIP request used to query capabilities or liveness without creating a full session.

PRACK is the SIP request that acknowledges a reliable provisional response.

PUBLISH is the SIP request used to publish event state toward a server that manages subscriptions.

REFER is the SIP request used to ask the far side to contact a third target or follow a transfer-related action.

REGISTER is the SIP request that creates, refreshes, or removes IMS service reachability for the UE.

SUBSCRIBE is the SIP request that creates or refreshes a subscription to an event package.

UPDATE is the SIP request used to modify session parameters inside an existing early or confirmed dialog.

Activate Dedicated EPS Bearer Context Accept is the EPS session-management message the UE sends to confirm that the dedicated bearer requested by the network was accepted and activated successfully.

Activate Dedicated EPS Bearer Context Reject is the LTE NAS message the UE sends when it cannot accept the dedicated bearer the network tried to activate.

Activate Dedicated EPS Bearer Context Request is the EPS session-management message the network sends when it wants the UE to activate a dedicated bearer linked to an already active default bearer.

Activate Default EPS Bearer Context Accept is the EPS session-management message the UE sends to confirm that the default bearer requested by the network was accepted and activated.

Activate Default EPS Bearer Context Reject is the LTE NAS message the UE sends when it cannot accept the default bearer the network tried to activate.

Activate Default EPS Bearer Context Request is the EPS session-management message the network sends to the UE when it wants to activate the default bearer for a PDN connection.

Attach Accept is the EPS NAS message the MME uses to grant LTE attach and deliver the accepted EPS mobility context to the UE.

Attach Complete is the EPS NAS message the UE sends after Attach Accept to confirm that the granted attach context was received and processed.

Attach Reject is the EPS NAS message the network sends when the corresponding LTE attach request is not accepted.

Attach Request is the EPS NAS message the UE uses to start the LTE attach procedure and ask the network to create EPS mobility-management context.

Authentication Failure is the EPS NAS message the UE sends when it cannot accept or complete the LTE/EPS authentication challenge normally.

Authentication Reject is the EPS NAS message the network sends when the LTE/EPS authentication attempt is not accepted and the current procedure cannot continue.

Authentication Request is the EPS NAS message the MME uses to challenge the UE during EPS NAS authentication and verify the subscriber before later security and mobility procedures continue.

Authentication Response is the EPS NAS message the UE sends after Authentication Request to return the calculated response parameter and let EPS authentication continue.

Bearer Resource Allocation Reject is the LTE NAS message the network sends when it refuses the UE's request for a dedicated bearer resource.

Bearer Resource Allocation Request is the LTE NAS message the UE sends when it wants the network to allocate a dedicated bearer resource for an active PDN connection.

Bearer Resource Modification Reject is the LTE NAS message the network sends when it refuses the UE's request to modify an existing bearer resource.

Bearer Resource Modification Request is the LTE NAS message the UE sends when it wants to change QoS or traffic-flow settings for an existing dedicated bearer resource.

Control Plane Service Request is the LTE NAS message the UE sends when service restoration uses control-plane CIoT EPS optimization instead of the normal user-plane service request path.

CS Service Notification is the LTE NAS message the network sends when it needs to notify the UE about an incoming CS-related service branch such as CS fallback.

Deactivate EPS Bearer Context Accept is the LTE NAS message the UE sends after it released the bearer the network asked it to deactivate.

Deactivate EPS Bearer Context Request is the EPS session-management message the network sends when it wants the UE to release a default or dedicated bearer context that is no longer needed.

Detach Accept is the EPS NAS message used to confirm that the detach procedure has been completed, either as the network response to a UE-originated detach or as the UE response to a network-initiated detach.

Detach Request is the EPS NAS message used to release EPS mobility-management context, either when the UE starts detach itself or when the network orders the UE to detach.

Downlink Generic NAS Transport is the LTE NAS message the network sends when it needs to carry a generic payload through the EMM layer.

Downlink NAS Transport is the EPS mobility-management message the network sends to carry an encapsulated SMS NAS payload toward the UE over LTE NAS signaling.

EMM Information is the EPS mobility-management message the network sends when it wants to deliver operator display names, time zone information, or related informational context to the UE during an established EMM context.

EMM Status is the LTE NAS message used to report an EMM protocol error, invalid state, or message-format problem back to the peer.

ESM Data Transport is the LTE NAS message used to carry small user data through the control plane when control-plane CIoT EPS optimization is in use.

ESM Dummy Message is the LTE NAS session-management message used as a minimal protected ESM payload in specific control-plane or procedure-maintenance branches.

ESM Information Request is the LTE NAS session-management message the network sends when it needs protected APN or protocol configuration details before completing PDN handling.

ESM Information Response is the LTE NAS session-management message the UE sends to return APN or protocol configuration detail after ESM Information Request.

ESM Status is the LTE NAS message used to report an ESM protocol error, invalid state, or malformed session-management message.

Extended Service Request is the EPS NAS message the UE sends when the service request procedure needs the extended LTE NAS form, especially for CS fallback, 1xCS fallback, or packet services via S1.

GUTI Reallocation Command is the LTE NAS message the MME sends when it wants the UE to replace its current GUTI with a newly allocated identity.

GUTI Reallocation Complete is the LTE NAS message the UE sends to confirm that it accepted and stored the new GUTI.

Identity Request is the EPS NAS message the MME sends when it needs the UE to provide a specific identity before the NAS procedure can continue.

Identity Response is the EPS NAS message the UE sends after Identity Request to return the specific identity the MME asked for so the LTE NAS procedure can continue.

Modify EPS Bearer Context Accept is the LTE NAS message the UE sends after it applied the bearer update requested by the network.

Modify EPS Bearer Context Reject is the LTE NAS message the UE sends when it cannot accept a bearer modification proposed by the network.

Modify EPS Bearer Context Request is the LTE NAS message the network sends when it wants to change bearer parameters that are already active on the UE.

Notification is the LTE NAS message the network sends when it needs to inform the UE about a specific NAS-side event that affects later handling.

PDN Connectivity Request is the EPS session-management message the UE sends when it wants connectivity to a PDN, either during attach or later as a standalone LTE NAS session request.

PDN Disconnect Reject is the LTE NAS session-management message the network sends when it refuses the UE's request to release a PDN connection.

PDN Disconnect Request is the LTE NAS session-management message the UE sends when it wants to release one PDN connection and its associated default bearer.

Remote UE Report is the LTE NAS message used in remote UE or CIoT handling to report remote-device status or event information toward the network.

Remote UE Report Response is the LTE NAS message the network sends after it processes a Remote UE Report.

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

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

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

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

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

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.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.

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

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

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.

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

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

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

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

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

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

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

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

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

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

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

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.

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

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

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

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.

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.

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.

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

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.

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

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

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

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.

Broadcast LTE RRC message carrying bandwidth-reduced system information.

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

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

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

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

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.

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.

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

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

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

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

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

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

Security Mode Command is the EPS NAS message the MME sends to activate the selected NAS security algorithms and move the LTE/EPS procedure into protected signaling.

Security Mode Complete is the EPS NAS message the UE sends to confirm that it accepted the selected NAS security algorithms and has switched into the commanded protected state.

Security Mode Reject is the EPS NAS message the UE sends when it cannot accept the NAS security configuration selected by the MME in Security Mode Command.

Service Accept is the EPS NAS message the network sends when the service request procedure is accepted and active service can continue using the existing EPS context.

Service Reject is the EPS NAS message the network sends when the service request procedure is not accepted.

Service Request is the EPS NAS message the UE uses to restore a NAS signaling connection and re-establish radio and S1 bearers while valid EPS context already exists.

Tracking Area Update Accept is the EPS NAS message the MME uses to accept the tracking area updating procedure and return the updated EPS mobility context to the UE.

Tracking Area Update Complete is the EPS NAS message the UE sends after Tracking Area Update Accept when the accepted TAU branch requires explicit UE completion.

Tracking Area Update Reject is the EPS NAS message the network sends when the tracking area updating procedure is not accepted.

Tracking Area Update Request is the EPS NAS message the UE uses to update the network about tracking-area change, periodic presence, or related EPS mobility-context refresh.

Uplink Generic NAS Transport is the LTE NAS message the UE sends when it needs to carry a generic payload through the EMM transport branch.

Uplink NAS Transport is the EPS mobility-management message the UE sends to carry an encapsulated SMS NAS payload toward the network over LTE NAS signaling.