| Protocol | rrc | Network | 5g |
|---|---|---|---|
| Spec | 3GPP TS 38.331 | Spec Section | 6.2.2 |
| Direction | gNB / donor -> IAB node | Message Type | IAB Control |
| Full message name | 5G NR - IAB Other Information |
|---|---|
| Protocol | RRC |
| Technology | 5G |
| Direction | gNB / donor -> IAB node |
| Interface | Uu / IAB backhaul radio link |
| Signaling bearer / channel | SRB1 / SRB2 / DL-DCCH |
| Typical trigger | Used when the donor or serving node needs to deliver extra IAB-specific information to the IAB node. |
| Main purpose | Provides additional IAB-related control information that does not fit into the most common setup or reconfiguration message flows. |
| Main specification | 3GPP TS 38.331, 6.2.2 |
| Release added | Release 16 |
| Procedures where used | IAB Configuration, IAB Maintenance |
IAB Other Information is an NR RRC message used to deliver additional IAB-specific information needed by an IAB node.
Provides additional IAB-related control information that does not fit into the most common setup or reconfiguration message flows.
IAB Other Information is an auxiliary RRC message for delivering extra IAB-specific information.
Call flow position: Used as an auxiliary IAB control message when extra information must be delivered.
Typical state: IAB node has an active control context.
Preconditions:
Next likely message: Follow-on IAB handling or later reconfiguration
Previous message(s): RRC Reconfiguration
Next message(s): IAB node applies the delivered information
Security context: Protected connected-mode signaling in IAB context.
IABOtherInformation ::= SEQUENCE {
iab-OtherInfoContainer OCTET STRING
}
Engineers usually inspect the message when a donor-to-IAB exchange contains extra control information outside the most common dedicated message types.
DL-DCCH-Message
message: iabOtherInformation
iab-OtherInfoContainer: present
| IE | Required | Description |
|---|---|---|
iab-OtherInfoContainer | Yes | Carries the IAB-specific information block that the receiving node must interpret. |
iab-OtherInfoContainerCarries the IAB-specific information block that the receiving node must interpret.
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 additional IAB information may be missing or not applied.
What to inspect: Check the IAB information container and the timing of its delivery.
Next step: Correlate this message with surrounding IAB reconfiguration or maintenance traces.
It is used when the network needs to send extra IAB-specific control information to an IAB node.
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.