R1-2601819
discussion
Discussion on other physical layer signals, channels and procedure
From Spreadtrum
Spreadtrum's prior position on
10.5.5
at
RAN1#124
· AI-synthesized, paraphrased
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Proposes that 6G Radio physical uplink control signaling carry scheduling request combined with other UCI, and supports SR+BSR as the preferred mechanism over contention-based UL transmission, arguing CBUL is not suitable for latency-sensitive data due to non-deterministic access latency affected by resource periodicity and UE sharing count. Proposes Rel-17 NR UL power control framework (open-loop and closed-loop) as the baseline for 6G power control, reusing beam-based transmissions, multiple numerologies, and DL RS for path loss measurement, with NR PHR as the baseline for 6G PHR. Observes overlapping functionalities between L1 and L3 CLI measurement schemes in NR and proposes a unified UE-to-UE CLI measurement and reporting scheme for SBFD operation. Proposes using Rel-19 gNB-to-gNB co-channel CLI/channel measurements as a starting point with information exchange among gNBs and transparent/non-transparent UL resource muting. For NR-6G MRSS, proposes resource allocation coordination to prevent conflicts, aligned numerology/waveform, and aligned UL/DL TDD direction to avoid cross-slot interference.
Summary
This Spreadtrum contribution discusses other physical layer signals, channels, and procedures for 6GR, focusing on scheduling request mechanisms, interference management (UE-to-UE, BS-to-BS, remote), and NR-6GR coexistence. The document contains 11 numbered proposals/observations across these areas.
Position
Spreadtrum requires that 6GR physical uplink control signaling carry scheduling requests combinable with other UCI, and requires support for the SR+BSR mechanism while proposing further study of contention-based UL transmission. For interference management, they propose studying UE-to-UE and BS-to-BS CLI handling specifically for gNB semi-static SBFD and dynamic TDD deployment scenarios, and propose a detailed taxonomy of CLI types including co-channel intra-subband, co-channel inter-subband, and adjacent-channel categories for both UE-to-UE and BS-to-BS links. They present a technical case for unified UE-to-UE CLI measurement and reporting across multiple duplex types, recommending SRS-RSRP and CLI-RSSI as candidate measurement resources/quantities and proposing to limit reporting to only one of L1 or L3 CLI reporting with network-controlled periodic and aperiodic mechanisms. They propose spatial domain solutions for UE-to-UE CLI handling but note potential limited gain in FR1 due to small UE antenna size, and argue that power control based solutions should be applied carefully to avoid degrading UL performance or DL throughput.
Key proposals
- Proposal 1 (Sec 2.1): 6GR physical uplink control signaling should be able to carry scheduling request which can be combined with other uplink control information.
- Proposal 2 (Sec 2.1): SR + BSR mechanism for acquiring UL data resources should be supported in 6GR, and Contention-based UL transmission for acquiring UL data resources can be further studied.
- Proposal 3 (Sec 2.2): UE-to-UE and BS-to-BS CLI handling should be studied for gNB semi-static SBFD and Dynamic TDD deployment scenarios.
- Proposal 4 (Sec 2.2): The following basic CLI types could be considered in 6GR: UE-to-UE (intra-band, co-channel intra-subband, co-channel inter-subband, adjacent channel) and BS-to-BS (intra-band, inter-site co-channel intra-subband, co-site inter-sector co-channel intra-subband, co-site inter-sector co-channel inter-subband, inter-site co-channel inter-subband, co-site adjacent-channel, inter-site adjacent-channel).
- Proposal 5 (Sec 2.2): High-level aspects to consider for NR-6GR MRSS interference management: resource allocation coordination, aligned numerology and waveform, and aligned UL/DL direction in TDD operation.
- Proposal 6 (Sec 2.2.1): Consider unified UE-to-UE CLI measurement and reporting for multiple duplex types.
- Proposal 7 (Sec 2.2.1): The following aspects could be the starting point to study UE-to-UE CLI measurement and reporting: periodic/semi-persistent/aperiodic measurement resource; candidate measurement resources SRS-RSRP and CLI-RSSI; candidate measurement quantities SRS-RSRP and CLI-RSSI; reporting mechanisms limited to only one of L1 and L3 CLI reporting with network-controlled periodic and aperiodic reporting.
- Proposal 8 (Sec 2.2.1): Study following UE-to-UE CLI techniques other than measurement and reporting: coordinated scheduling in time and/or frequency, spatial domain solution, power control based solution.
- Proposal 9 (Sec 2.2.2): Consider BS-to-BS co-channel CLI and/or channel measurements introduced in R19 as starting point: information exchange among gNBs, transparent/non-transparent UL resource muting, DL signal(s)/channel(s) as measurement resources (e.g., SSB, CSI-RS).
- Proposal 10 (Sec 2.2.2): Study following BS-to-BS CLI techniques other than measurement: coordinated scheduling for time/frequency resources between gNBs, spatial domain based solution, power control based solution.
- Proposal 11 (Sec 2.2.3): The wireless-based and backhaul-based RIM frameworks in 5G can be the starting point for study remote interference management in 6GR.