| Protocol | lte-rrc | Network | lte |
|---|---|---|---|
| Spec | 3GPP TS 36.331 | Spec Section | 5.10, 6.2.2 |
| Direction | UE -> eNodeB | Message Type | Sidelink Reporting |
| Full message name | LTE RRC Sidelink UE Information r12 |
|---|---|
| Protocol | LTE-RRC |
| Technology | LTE |
| Direction | UE -> eNodeB |
| Interface | Uu |
| Signaling bearer / channel | SRB1 / UL-DCCH |
| Typical trigger | Triggered when the UE needs to report sidelink-related information. |
| Main purpose | Lets the network receive sidelink-related UE context so it can continue sidelink-aware handling. |
| Main specification | 3GPP TS 36.331, 5.10, 6.2.2 |
| Release added | Release 12 |
| Procedures where used | Sidelink information reporting |
Uplink LTE RRC message used by the UE to report sidelink-related information to the network.
Lets the network receive sidelink-related UE context so it can continue sidelink-aware handling.
Sidelink UE Information r12 is the LTE UE message used to report sidelink-related context to the network.
Call flow position: UE report sent when sidelink-related context must be exposed to the network.
Typical state: The network can use the report to continue sidelink-aware handling.
Preconditions:
Next likely message: Later sidelink-aware continuation
Call flow position: UE update sent when sidelink-related status changed or became relevant.
Typical state: The report helps the network understand the sidelink branch rather than ordinary LTE-only behavior.
Preconditions:
Next likely message: Connected-mode continuation or later reconfiguration
Previous message(s): RRCConnectionReconfiguration
Next message(s): Later sidelink-aware continuation
Security context: Sent as protected connected-mode signaling.
SidelinkUEInformation-r12 ::= SEQUENCE {
criticalExtensions CHOICE {
c1 CHOICE {
sidelinkUEInformation-r12 SidelinkUEInformation-r12-IEs,
spare3 NULL,
spare2 NULL,
spare1 NULL
},
criticalExtensionsFuture SEQUENCE {}
}
}
Read it as sidelink-related reporting rather than a normal mobility or broadcast message.
UL-DCCH-Message
message c1 : sidelinkUEInformation-r12 : {
criticalExtensions c1 : sidelinkUEInformation-r12 : {
sidelinkUEInformation-r12 present
}
}
| IE | Required | Description |
|---|---|---|
sidelinkUEInformation-r12 | Yes | Carries the UE's sidelink-related information. |
sidelinkUEInformation-r12Carries the UE's sidelink-related information.
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 sidelink-related UE report may be missing or not reflected in later handling.
What to inspect: Check whether Sidelink UE Information r12 appears and what payload it carries.
Next step: Treat the issue as sidelink-related reporting rather than ordinary LTE-only control.
It is the uplink LTE RRC message the UE uses to report sidelink-related information to the network.
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.