3GPP AIML RRC Parameters for Ue Capability
For years, the radio access network has been guessing. Every scheduling decision, every beam selection, every channel estimate has been built on the network's best inference of how a device actually experiences the radio environment. With 3GPP Release 19, that dynamic begins to change in a formal, standardized way — and the evidence is sitting right there in the UE capability signaling.
The introduction of AIML-Parameters-r19 is, on its surface, just another capability container. In practice, it represents a turning point: the device itself can now run trained models to support functions like beam management, CSI feedback, and positioning, and — critically — it can tell the network exactly what it's capable of.
Where it lives in the specification:
The ASN.1 follows the familiar 3GPP non-critical extension chain. Release 18's capability structure hands off to a new Release 19 container, and that's where the AI/ML parameters make their debut:
asn1
UE-NR-Capability-v1860 ::= SEQUENCE {
ntn-CHO-OnlyLocationTimeTrigger-r18 ENUMERATED { supported } OPTIONAL,
nonCriticalExtension UE-NR-Capability-v1900 OPTIONAL
}
UE-NR-Capability-v1900 ::= SEQUENCE {
aiml-Parameters-r19 AIML-Parameters-r19 OPTIONAL,
ue-RadioPagingInfo-r19 OCTET STRING (CONTAINING UE-RadioPagingInfo-r19) OPTIONAL,
ntn-VSAT-AntennaTypeKuBand-r19 ENUMERATED { electronic, mechanical } OPTIONAL,
ntn-VSAT-MobilityTypeKuBand-r19 ENUMERATED { fixed, mobile } OPTIONAL,
ntn-ERedCap-FR1-r19 ENUMERATED { supported } OPTIONAL,
onDemandSIB1-r19 ENUMERATED { supported } OPTIONAL,
onDemandPosSIB-ConnectedCtrlParam-r19 ENUMERATED { supported } OPTIONAL,
ntn-Redirection-r19 ENUMERATED { supported } OPTIONAL,
drx-PreferenceCellDTX-DRX-r19 ENUMERATED { supported } OPTIONAL,
lpwus-SupportedBandsIdleInactiveOFDM-r19 SEQUENCE (SIZE (1..maxBands)) OF FreqBandIndicatorNR OPTIONAL,
lpwus-SupportedBandsIdleInactiveOOK-r19 SEQUENCE (SIZE (1..maxBands)) OF FreqBandIndicatorNR OPTIONAL,
nonCriticalExtension UE-NR-Capability-v1920 OPTIONAL
}
AIML-Parameters-r19 ::= SEQUENCE {
applicabilityReportingCSI-r19 ENUMERATED { supported } OPTIONAL,
applicabilityReportingOther-r19 ENUMERATED { supported } OPTIONAL,
loggedDataCollection-r19 ENUMERATED { supported } OPTIONAL,
eventBasedLoggedDataCollection-r19 ENUMERATED { supported } OPTIONAL,
dataThresholdAvailabilityIndication-r19 ENUMERATED { supported } OPTIONAL
}By anchoring these fields under UE-NR-Capability-v1900, 3GPP is sending an unambiguous message: Release 19 is the formal starting point for standardized AI/ML capability signaling. This isn't a vendor experiment or a proprietary extension — it's part of the specification itself.
Why a capability framework matters more than the models
It's tempting to focus on the models — the neural networks predicting beams or compressing channel state feedback. But the harder engineering problem has always been trust and control. AI in a mobile network cannot operate as an uncontrolled black box. Before the network can rely on a device's intelligence, it needs answers to three questions: Can this UE do AI-related processing at all? Is the model it's running still valid in the current radio environment? And can this device contribute useful data toward improving the next generation of models?
The AIML-Parameters-r19 structure answers all three. Walking through the fields makes the design philosophy clear.
Knowing when the model can be trusted. The applicabilityReportingCSI-r19 field indicates whether the UE can report the applicability of its AI model specifically for Channel State Information — in other words, whether the device can tell the network "my CSI model is reliable here" or "conditions have drifted; don't lean on my predictions." Its sibling, applicabilityReportingOther-r19, extends the same idea to other use cases such as beam management and positioning. A model trained in one deployment scenario may degrade in another, and these fields give the network the visibility it needs to manage that risk rather than discover it the hard way.
Turning devices into data sources. The loggedDataCollection-r19 field confirms that the UE can collect and store radio signal measurements for use as training data. Its event-based counterpart, eventBasedLoggedDataCollection-r19, is the smarter variant: rather than logging continuously, the device can trigger collection only when something interesting happens — a handover failure, a sudden signal drop. The most valuable training data often comes from exactly these edge cases, and event-based logging captures them without burning battery and memory on routine measurements.
Knowing when there's enough. Finally, dataThresholdAvailabilityIndication-r19 lets the UE proactively inform the network that it has accumulated enough data to be useful for model training or updates. Instead of the network polling devices blindly, devices raise their hand when they have something worth fetching.
The bigger picture:
Taken together, these five optional fields do something subtle but important: they make AI/ML a controlled, predictable component of radio resource management. The network can discover capability, monitor model validity, and orchestrate a data lifecycle — all through standard RRC signaling, all interoperable across vendors.
That's the real story of Release 19. The transition to an AI-native air interface won't arrive as a single dramatic feature. It arrives like this: one capability container at a time, with the groundwork for trust laid before the intelligence is switched on. The devices in your pocket are about to become active participants in how the network learns — and now there's a standardized language for the conversation.
AI/ML Meets
the Air Interface
How AIML-Parameters-r19 transforms UE Capability signaling — making artificial intelligence a controlled, standards-based part of radio resource management.
UE-NR-Capability-v1900
AI Cannot Be an Uncontrolled Black Box
The network must know whether the UE is AI-capable, whether its model is valid, and whether it can contribute training data.
The introduction of AIML-Parameters-r19 marks the transition toward an AI/ML-based air interface. Instead of the network trying to infer how the UE perceives the radio environment, the UE can now leverage trained models to support critical functions — beam management, CSI feedback, and positioning.
By placing these fields under UE-NR-Capability-v1900, 3GPP establishes Release 19 as the formal starting point for standardized AI/ML capability signaling. This capability framework transforms AI and ML from experimental features into a controlled and predictable part of radio resource management.
ASN.1 Capability Structure
Release 19 extends the non-critical extension chain to introduce AI/ML capability signaling at the RRC layer.
AIML-Parameters-r19 — ASN.1 Definition
Five Parameters. One AI-Native Framework.
Click any parameter to explore its technical purpose, network impact, and use-case relevance.
Reports whether the UE's AI model for Channel State Information is reliable under current radio conditions. Enables the network to trust or discard AI-generated CSI feedback.
Extends model applicability reporting to other AI/ML use cases beyond CSI, including beam management and positioning — enabling the network to manage diverse AI workloads.
Confirms the UE can collect and store radio signal measurements for use as training data for machine learning models — enabling a continuous model improvement loop.
Triggers data logging only on specific radio events — handover failures, signal drops, beam failures — capturing the exact conditions where models fail and need improvement.
Informs the network that the UE has accumulated enough logged data to be useful for model training or model updates — enabling efficient data transfer scheduling.
How the Framework Operates
From capability exchange to continuous model improvement — a closed-loop AI/ML lifecycle at the air interface.
CSI Prediction:
The First AI/ML Frontier
Channel State Information prediction is the primary use case driving AIML-Parameters-r19. Instead of relying solely on reference signal measurements, the UE uses a trained neural network to predict future channel conditions — reducing measurement overhead while maintaining scheduling accuracy.
The applicabilityReportingCSI-r19 parameter is specifically designed for this function, enabling the UE to report when its CSI prediction model is no longer accurate due to environmental changes.
- Up to 90% reduction in CSI-RS overhead with AI-compressed feedback
- Predictive beam tracking in high-mobility FR2 scenarios
- Controlled fallback to legacy codebook when model validity degrades
- Network-side confidence scoring via applicability reports
- 3GPP TS 38.331 v19.2.0 : NR; Radio Resource Control (RRC); Protocol specification
- 3GPP TS 38.306 : NR; User Equipment (UE) radio access capabilities
- 3GPP TS 38.214 : NR; Physical layer procedures for data
- 3GPP TS 37.355 : LTE Positioning Protocol (LPP)
- 3GPP TR 38.843 : Study on Artificial Intelligence (AI)/Machine Learning (ML) for NR air interface
- 3GPP TR 38.744 : Study on Artificial Intelligence (AI)/Machine Learning (ML) for mobility in NR
- RP-234039 : New WID on Artificial Intelligence (AI)/Machine Learning (ML) for NR air interface (Release 19 Work Item Description)
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