R1-2603167
discussion
Discussion on LS reply to RAN2 on capability reporting for PRS Processing Window
From Huawei
Summary
This document addresses a Letter of Agreement from RAN2 regarding whether specific UE positioning capabilities (FG 58-2-9, 58-2-10, 58-2-11) for PRS Processing Windows should be reported to the gNB. Huawei argues that reporting these capabilities violates the architectural assumption that the gNB should not be aware of the specific UE-based positioning method, and that doing so creates ambiguity with legacy capability reporting. The document contains 2 observations and 1 proposal.
Position
Huawei opposes reporting FG 58-2-9, FG 58-2-10, and FG 58-2-11 to the gNB, arguing that this violates the general architectural assumption that the gNB should not be aware of the UE-based positioning method selected by the LMF. They present a technical case against duplicate capability reporting, noting that legacy capabilities FG 27-3-2, FG 27-3-3, and FG 27-23 are sufficient for the gNB to handle PRS processing window (PPW) configuration and priority handling. Huawei argues that introducing separate reporting for Case 1 creates ambiguity at the gNB regarding which capability values to consider if they differ from legacy reports. They conclude that the report of these specific features to the gNB is not necessary.
Key proposals
- Proposal 1 (Discussion on the LS reply): Reply the RAN2 LS confirming that FG 58-2-9, FG 58-2-10, and FG 58-2-11 should not be reported to the gNB.
- Observation 1 (Discussion on the LS reply): Assert that the general architectural assumption for NR positioning requires the gNB to remain unaware of the UE-based positioning method for which the UE receives PRS, applying this to UE-based positioning Case 1.
- Observation 2 (Discussion on the LS reply): Highlight that reporting both new capabilities (FG 58-2-9/10/11) and legacy capabilities (FG 27-3-2, 27-2-3, 27-23) to the gNB results in ambiguity regarding which capability values the gNB should consider.