LTE RRC Early Data Complete-r15

Message Fact Sheet

Protocol	lte-rrc	Network	lte
Spec	3GPP TS 36.331	Spec Section	5.3.3, 6.2.2
Direction	eNodeB -> UE	Message Type	CP-EDT Completion

Full message name	LTE RRC Early Data Complete-r15
Protocol	LTE-RRC
Technology	LTE
Direction	eNodeB -> UE
Interface	Uu
Signaling bearer / channel	SRB0 / DL-CCCH
Typical trigger	The network accepts and completes the control-plane early data branch.
Main purpose	Closes the early-data exchange and optionally carries the downlink NAS container or branch-completion information.
Main specification	3GPP TS 36.331, 5.3.3, 6.2.2
Release added	Release 15
Procedures where used	Control Plane Early Data Transmission, Small Data Access
Related timers	T302

What is LTE RRC Early Data Complete-r15 in simple terms?

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

Closes the early-data exchange and optionally carries the downlink NAS container or branch-completion information.

Why this message matters

RRC Early Data Complete-r15 is the LTE message that closes the control-plane early data branch.

Where this message appears in the call flow

Control-plane early data completion

Call flow position: Completion step after the network accepts the small-data branch.

Typical state: UE is still on the early CCCH path.

Preconditions:

RRCEarlyDataRequest-r15 was accepted.

Next likely message: Idle return or later service continuation

CP-EDT with downlink NAS response

Call flow position: Completion branch where the network also returns downlink NAS content.

Typical state: UE is finishing the early-data exchange.

Preconditions:

The network has completion content ready.

Next likely message: Idle-side continuation

Call flow position

Previous message(s): RRCEarlyDataRequest-r15

Next message(s): Idle return, Later fresh access if needed

Message direction and transport

Sender and receiver: eNodeB -> UE

Interface: Uu

Domain: Access-side early data control

Signaling bearer: SRB0

Logical channel: DL-CCCH

Transport / encapsulation: RRC over CCCH on the CP-EDT completion path

Security context: Sent on the early data completion branch before the ordinary full connected-mode path is established.

Message Structure Overview

RRCEarlyDataComplete-r15 is the network-side closure message for the CP-EDT branch.
The useful reading points are whether downlink NAS content is returned and what the UE does after completion.

ASN.1 for LTE RRC Early Data Complete-r15

RRCEarlyDataComplete-r15 ::= SEQUENCE {
  criticalExtensions CHOICE {
    c1 CHOICE {
      rrcEarlyDataComplete-r15 RRCEarlyDataComplete-r15-IEs,
      spare3 NULL,
      spare2 NULL,
      spare1 NULL
    },
    criticalExtensionsFuture SEQUENCE {}
  }
}

RRCEarlyDataComplete-r15-IEs ::= SEQUENCE {
  dedicatedInfoNAS-r15       DedicatedInfoNAS OPTIONAL,
  redirectedCarrierInfo-r15  OCTET STRING OPTIONAL,
  nonCriticalExtension       SEQUENCE {} OPTIONAL
}

How to read this ASN.1

Read this message as the completion marker for the early-data branch, with any optional downlink NAS or redirection payload.

LTE RRC Early Data Complete-r15 - Example Dump

DL-CCCH-Message
  message c1 : rrcEarlyDataComplete-r15 : {
    criticalExtensions c1 : rrcEarlyDataComplete-r15 : {
      dedicatedInfoNAS-r15 '270102'H
    }
  }

How to read this dump

Check whether dedicatedInfoNAS-r15 is present.
Then confirm what the UE does immediately after the completion.

Important Information Elements

IE	Required	Description
`dedicatedInfoNAS-r15`	Optional	Optional downlink NAS payload returned when the early-data branch includes a downlink response.
`redirectedCarrierInfo-r15`	Optional	Optional redirection-related information returned in specific cases.
`nonCriticalExtension`	Optional	Release-extension branch.

Detailed field explanation

`dedicatedInfoNAS-r15`

Optional downlink NAS payload returned when the early-data branch includes a downlink response.

Presence: Optional

In practice: In practice, compare this field with the original request and with any later release-dependent optional fields so you can see whether the network accepted the same service model the UE asked for.

`redirectedCarrierInfo-r15`

Optional redirection-related information returned in specific cases.

Presence: Optional

In practice: In practice, compare this field with the original request and with any later release-dependent optional fields so you can see whether the network accepted the same service model the UE asked for.

`nonCriticalExtension`

Release-extension branch.

Presence: Optional

In practice: In practice, compare this field with the original request and with any later release-dependent optional fields so you can see whether the network accepted the same service model the UE asked for.

What to check in logs and traces

Confirm the message follows RRCEarlyDataRequest-r15.
Check for optional downlink NAS content.
Follow the UE into idle return or later service continuation.

Common Issues and Troubleshooting

The early-data request is accepted but the expected small-data outcome is unclear.

Likely cause: The branch may have completed, but the optional downlink payload or later UE behavior was not read correctly.

What to inspect: Check this completion message and the immediate UE behavior afterward.

Next step: Treat the branch as completed first, then analyze the later service outcome.

FAQ

What is RRCEarlyDataComplete-r15 in LTE?

It is the LTE RRC message the network uses to close the control-plane early data branch.

Related message pages

Related Procedures

Related Tools

Use This Reference in Practice

Decode this message with the 3GPP Decoder, inspect the related message database, or open the matching call flow to see where this signaling step fits in the full procedure.