Most of the practical value is inside the returned RAT capability containers. Engineers should inspect what RAT capability blocks are present and whether the network later interprets them correctly.
The important part is the returned RAT capability container list.
In practical traces, the NR capability container can be large and deeply structured.
If later configuration fails, compare the network decision against what the UE actually reported here.
Important Information Elements
IE
Required
Description
rrc-TransactionIdentifier
Yes
Transaction identifier used to correlate the UE response with the preceding UECapabilityEnquiry.
ue-CapabilityRAT-ContainerList
Yes
List of UE capability containers reported by the UE for the requested RATs.
lateNonCriticalExtension
Optional
Extension container used for later release evolution and compatibility handling.
nonCriticalExtension
Optional
Forward-compatible extension branch for later additions.
Detailed field explanation
rrc-TransactionIdentifier
Transaction identifier used to correlate the UE response with the preceding UECapabilityEnquiry.
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.
ue-CapabilityRAT-ContainerList
List of UE capability containers reported by the UE for the requested RATs.
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.
lateNonCriticalExtension
Extension container used for later release evolution and compatibility handling.
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
Forward-compatible extension branch for later additions.
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 UECapabilityEnquiry and uses SRB1 / UL-DCCH.
Verify the transaction identifier matches the preceding enquiry.
Inspect which RAT capability containers are present.
Check whether the reported capability content is complete and consistent with the scenario.
Correlate the message with the following RRCReconfiguration or other network action.
Common Issues and Troubleshooting
UECapabilityInformation is present but later feature configuration fails.
Likely cause: The network may have misread or misused the reported capability data, or the UE report may be incomplete for the intended feature.
What to inspect: Compare the returned capability containers with the later RRCReconfiguration content.
Next step: Validate that the configured features are actually declared as supported in the UE report.
Capability reporting looks incomplete or missing expected containers.
Likely cause: The enquiry may not have requested the full set needed, the decoder may be incomplete, or the UE may not report the expected capability data.
What to inspect: Check UECapabilityEnquiry first, then compare the requested and returned RAT lists.
Next step: Confirm whether the missing container is truly absent or just not decoded in the current toolchain.
Repeated capability exchange occurs.
Likely cause: The network may be revalidating capability context after context loss, mobility, or implementation-specific behavior.
What to inspect: Check whether the repeated exchange corresponds to a new connected-mode context or procedure restart.
Next step: Determine whether the repeat procedure is expected before treating it as abnormal.
LTE / 5G / Variant Comparison
Compared with UECapabilityEnquiry
UECapabilityEnquiry asks for capability data. UECapabilityInformation carries the actual UE-reported capability containers.
FAQ
What does UECapabilityInformation do in 5G NR?
It reports the UE's radio capability information back to the gNB.
Who sends UECapabilityInformation?
The UE sends UECapabilityInformation to the gNB.
What comes before UECapabilityInformation?
UECapabilityEnquiry normally comes immediately before it.
Why is UECapabilityInformation important?
It gives the network the capability data needed to build configuration that the UE can actually support.
Does UECapabilityInformation affect later RRCReconfiguration?
Yes. The reported capabilities often directly influence what the network configures next.
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.