R1-2500613
LS out
Draft LS reply on LMF-based positioning for case 2b
From NEC
Summary
NEC submits a Liaison Statement reply to SA2 regarding data collection for LMF-based AI/ML Positioning Case 2b, clarifying that detailed agreements are pending until Q1 2025. The document outlines existing RAN1 agreements from Meeting #116b, defining the structure of training data samples into Part A (channel measurements) and Part B (ground truth labels) and identifying potential entities for data generation.
Position
NEC clarifies that detailed data collection agreements for Case 2b are pending until Q1 2025, as it is a 2nd priority case. They present the existing RAN1#116b agreement which structures training data into Part A (channel measurement, quality indicator, timestamp) and Part B (ground truth label, quality indicator, timestamp), noting these terms are for discussion only. NEC supports the working assumption that labels for Case 2b can be generated by the PRU, non-PRU UE with estimated location, or the LMF. They confirm that channel measurements are generated by the PRU and/or non-PRU UE. NEC explicitly states that the transfer of label data is out of RAN1 scope.
Key proposals
- Observation (Sec 1): Case 2b is designated as the 2nd priority case, meaning detailed discussions on data collection were deferred until Q1 2025 (RAN#105), resulting in limited current agreements.
- Agreement (Sec 2, RAN1#116b): Training data samples for AI/ML positioning are structured into two parts: Part A containing channel measurement, quality indicator, and timestamp; and Part B containing ground truth label, quality indicator, and timestamp.
- Agreement (Sec 2, RAN1#116b): The terminologies 'Part A' and 'Part B' are strictly for RAN1 discussion purposes and may not appear in the final specification.
- Agreement (Sec 2, RAN1#116b): Part A and Part B contents may or may not be generated by different entities, and their applicability varies per case.
- FFS (Sec 2, RAN1#116b): The detailed definition of 'channel measurement' remains a Further Study Item (FFS).
- Agreement (Sec 2, RAN1#116b): For Case 2a and 2b, channel measurements and related data (e.g., timestamps) are generated by the Positioning Reference Unit (PRU) and/or non-PRU UE.
- Working Assumption (Sec 2, RAN1#116b): For Case 2b, the label and related data can be generated by the PRU, a non-PRU UE with estimated location, or the LMF.
- Scope Clarification (Sec 2, RAN1#116b): The transfer of labels and related data is explicitly stated to be out of RAN1 scope.