LTE NAS Messages

LTE NAS messages cover EPS mobility management and session management signaling between the UE and the MME, including attach, authentication, service handling, TAU, detach, and bearer-related control paths.

Use this LTE NAS message library to browse Attach Request and future EPS NAS references defined in 3GPP TS 24.301, with searchable metadata, message summaries, IE names, and protocol-level context.

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All Messages in This Category

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

NAS LTE

LTE Activate Dedicated EPS Bearer Context Accept

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Activate Dedicated EPS Bearer Context Reject

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Activate Dedicated EPS Bearer Context Request

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.

MME -> UE 3GPP TS 24.301
NAS LTE

LTE Activate Default EPS Bearer Context Accept

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Activate Default EPS Bearer Context Reject

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Activate Default EPS Bearer Context Request

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.

MME -> UE 3GPP TS 24.301
NAS LTE

LTE Attach Accept

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

MME -> UE 3GPP TS 24.301
NAS LTE

LTE Attach Complete

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

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Attach Reject

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

MME -> UE 3GPP TS 24.301
NAS LTE

LTE Attach Request

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Authentication Failure

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

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Authentication Reject

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.

MME -> UE 3GPP TS 24.301
NAS LTE

LTE Authentication Request

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.

MME -> UE 3GPP TS 24.301
NAS LTE

LTE Authentication Response

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

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Bearer Resource Allocation Reject

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

MME -> UE 3GPP TS 24.301
NAS LTE

LTE Bearer Resource Allocation Request

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Bearer Resource Modification Reject

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.

MME -> UE 3GPP TS 24.301
NAS LTE

LTE Bearer Resource Modification Request

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Control Plane Service Request

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE CS Service Notification

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.

MME -> UE 3GPP TS 24.301
NAS LTE

LTE Deactivate EPS Bearer Context Accept

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

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Deactivate EPS Bearer Context Request

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.

MME -> UE 3GPP TS 24.301
NAS LTE

LTE Detach Accept

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.

MME -> UE or UE -> MME 3GPP TS 24.301
NAS LTE

LTE Detach Request

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.

UE -> MME or MME -> UE 3GPP TS 24.301
NAS LTE

LTE Downlink Generic NAS Transport

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

MME -> UE 3GPP TS 24.301
NAS LTE

LTE Downlink NAS Transport

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.

MME -> UE 3GPP TS 24.301
NAS LTE

LTE EMM Information

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.

MME -> UE 3GPP TS 24.301
NAS LTE

LTE EMM Status

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

UE -> MME 3GPP TS 24.301
NAS LTE

LTE ESM Data Transport

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE ESM Dummy Message

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE ESM Information Request

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.

MME -> UE 3GPP TS 24.301
NAS LTE

LTE ESM Information Response

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

UE -> MME 3GPP TS 24.301
NAS LTE

LTE ESM Status

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

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Extended Service Request

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE GUTI Reallocation Command

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.

MME -> UE 3GPP TS 24.301
NAS LTE

LTE GUTI Reallocation Complete

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

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Identity Request

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.

MME -> UE 3GPP TS 24.301
NAS LTE

LTE Identity Response

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Modify EPS Bearer Context Accept

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

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Modify EPS Bearer Context Reject

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

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Modify EPS Bearer Context Request

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.

MME -> UE 3GPP TS 24.301
NAS LTE

LTE Notification

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.

MME -> UE 3GPP TS 24.301
NAS LTE

LTE PDN Connectivity Request

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE PDN Disconnect Reject

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.

MME -> UE 3GPP TS 24.301
NAS LTE

LTE PDN Disconnect Request

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Remote UE Report

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Remote UE Report Response

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

MME -> UE 3GPP TS 24.301
NAS LTE

LTE Security Mode Command

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.

MME -> UE 3GPP TS 24.301
NAS LTE

LTE Security Mode Complete

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Security Mode Reject

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Service Accept

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.

MME -> UE 3GPP TS 24.301
NAS LTE

LTE Service Reject

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

MME -> UE 3GPP TS 24.301
NAS LTE

LTE Service Request

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Tracking Area Update Accept

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.

MME -> UE 3GPP TS 24.301
NAS LTE

LTE Tracking Area Update Complete

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Tracking Area Update Reject

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

MME -> UE 3GPP TS 24.301
NAS LTE

LTE Tracking Area Update Request

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Uplink Generic NAS Transport

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.

UE -> MME 3GPP TS 24.301
NAS LTE

LTE Uplink NAS Transport

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.

UE -> MME 3GPP TS 24.301

Related Procedures