| Protocol | rrc | Network | 5g |
|---|---|---|---|
| Spec | 3GPP TS 38.331 | Spec Section | 5.3.13, 6.2.2 |
| Direction | UE -> gNB | Message Type | Connection Resume |
| Full message name | 5G NR - RRC Resume Request |
|---|---|
| Protocol | RRC |
| Technology | 5G |
| Direction | UE -> gNB |
| Interface | Uu |
| Signaling bearer / channel | SRB0 / UL-CCCH |
| Typical trigger | Used when the UE has an inactive or suspended context and needs to return to connected mode. |
| Main purpose | Starts the resume procedure so the network can restore the earlier connected context instead of creating a fresh setup. |
| Main specification | 3GPP TS 38.331, 5.3.13, 6.2.2 |
| Release added | Release 15 |
| Procedures where used | RRC Resume, Paging Response from Inactive, Inactive-to-Connected Transition |
| Related timers | T380 |
RRC Resume Request is the UE-to-network NR RRC message used to request resumption of a suspended or inactive context.
Starts the resume procedure so the network can restore the earlier connected context instead of creating a fresh setup.
RRC Resume Request asks the network to restore a previous inactive or suspended context.
Call flow position: First UE message in the resume path.
Typical state: UE is in RRC_INACTIVE or suspended state.
Preconditions:
Next likely message: RRC Resume or RRC Reject
Previous message(s): Paging, Resume trigger from upper layers
Next message(s): RRC Resume, RRC Reject
Security context: Sent before full connected context is restored.
RRCResumeRequest ::= SEQUENCE {
criticalExtensions CHOICE {
rrcResumeRequest RRCResumeRequest-IEs,
...
}
}
The key checks are which resume identity was used and whether the resume cause matches the scenario.
UL-CCCH-Message
message: rrcResumeRequest
resumeCause: mo-Data
| IE | Required | Description |
|---|---|---|
resumeIdentity | Yes | Identifies the suspended or inactive UE context to be resumed. |
resumeCause | Yes | Explains why the UE is requesting the resume. |
resumeIdentityIdentifies the suspended or inactive UE context to be resumed.
Presence: Required
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.
resumeCauseExplains why the UE is requesting the resume.
Presence: Required
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.
Likely cause: The resume identity may be missing, stale, or rejected.
What to inspect: Check the resume request and the immediate network response.
Next step: Compare it with any paging context and later setup behavior.
The network normally answers with RRC Resume if it accepts the request.
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.