R1-2601844
discussion
On other physical layer signals, channels and procedures in 6GR
From Nokia
Nokia's prior position on
10.5.5
at
RAN1#124
· AI-synthesized, paraphrased
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Proposes prioritizing layer-1 over layer-3 UE-to-UE CLI measurements for 6G Radio due to higher configuration flexibility and faster interference tracking, and requires re-using SRS-RSRP and CLI-RSSI as baseline reporting quantities while studying event-triggered reporting to reduce UE complexity and energy consumption. For RIM, prefers simplifying the 5G NR RIM design by prioritizing RIM Framework-1, down-prioritizing backhaul-signaling solutions due to one-to-many aggressor-victim cell relationships, and reducing RIM RS configurability parameters such as sequence numbers and bandwidth options (48 vs 96 PRBs) to improve inter-operability. For Cell DTX/DRX, proposes studying joint optimization with spatial/power domain adaptation and relaxation of cell-common signals/channels during non-active periods.
Summary
Nokia's 6GR contribution presents 19 proposals and 5 observations across four technical areas: cross-link interference (CLI) handling for advanced duplexing, remote interference management (RIM), scheduling request (SR), and MRSS coexistence, with particular emphasis on CLI measurement frameworks and RIM simplification.
Position
Nokia proposes using dynamic TDD and gNB semi-static SBFD as the starting duplexing schemes for CLI handling in 6GR. For UE-to-UE CLI, Nokia requires prioritizing layer-1 measurements over layer-3 measurements, citing faster tracking of interference conditions and spatial filter indications via QCL-TypeD, while preserving SRS-RSRP and CLI-RSSI as baseline reporting quantities and studying extension of RSSI to general interference measurement. Nokia proposes studying additional CLI handling schemes including power control-based schemes leveraging in-band emission properties and resource index reporting for aggressor UE identification without exact CLI level. For BS-to-BS CLI, Nokia supports 5G NR UL resource muting with comb-2 pattern as baseline while proposing new procedures beyond measurement exchange for gNB-to-gNB CLI mitigation. On RIM, Nokia requires basing the 6GR solution on 5G NR RIM design for MRSS compatibility but proposes simplifications including prioritizing RIM Framework-1 (victim-triggered RS-1 plus aggressor RS-2) over Framework-0, down-prioritizing backhaul-signaling-dependent frameworks (2.1, 2.2) due to one-to-many aggressor-victim relationships, and reducing RIM RS configurability. For scheduling request, Nokia proposes studying CB-PUSCH L1 aspects including DMRS and scrambling selection on shared time-frequency resources while considering dedicated SR mechanism as baseline for predictable latency.
Key proposals
- Proposal 2.1 (Sec 2): Use dynamic TDD and gNB semi-static SBFD duplexing schemes as starting point for the handling of cross-link interference in 6GR.
- Proposal 2.2 (Sec 2.1): Study UE-to-UE CLI measurement and reporting framework, as well as CLI mitigation mechanisms for scenarios with: dynamic TDD, SBFD, TDD-SBFD coexistence scenario.
- Proposal 2.8 (Sec 2.2): Study BS-to-BS measurement and reporting framework, as well as CLI mitigation mechanisms for scenarios with: dynamic TDD, SBFD, TDD-SBFD coexistence scenario.
- Proposal 2.12 (Sec 2.3): Cross-link interference handling in MRSS shall be postponed until a solid picture of the MRSS framework is in place.
- Proposal 3.1 (Sec 3): 6G deployments adopting static TDD and 6G MRSS deployments to be considered as reference scenarios for RIM discussions.
- Proposal 3.4 (Sec 3): For the 6G RIM design, consider RIM Framework-1 as highest priority and down-prioritize solutions requiring backhaul signaling due to high overhead; reduce the level of configurability of the RIM RS relative to the 5G NR design.
- Proposal 4.1 (Sec 4): Study mechanisms for reducing the overall waiting time – SR – BSR – grant process latency for 6GR while keeping the resource overhead reasonable; L1 aspects for both CB-PUSCH and SR mechanisms should be considered.
- Proposal 2.4 (Sec 2.1): Support layer-1 UE-to-UE CLI measurements and reporting in 6GR, whereas the layer-3 measurements can be de-prioritized.
- Proposal 2.6 (Sec 2.1): 6GR to use SRS-RSRP and CLI-RSSI as baseline reporting quantities for UE-to-UE CLI, study the option to extend RSSI measurement framework to general interference measurement.
- Proposal 2.7 (Sec 2.1): 6GR to study the additional schemes for UE-to-UE CLI handling (e.g. power control-based scheme, resource index reporting).
- Proposal 2.9 (Sec 2.2): 6GR to introduce measurement and reporting mechanisms for gNBs to identify the source of gNB-to-gNB CLI.
- Proposal 2.10 (Sec 2.2): 6GR to study new procedures for gNB-to-gNB CLI mitigation.
- Proposal 2.11 (Sec 2.2): 6GR to support 5G NR UL resource muting as baseline; further considerations to increase its flexibility can be studied.
- Proposal 3.2 (Sec 3): 6GR to support reference signals and detection and mitigation techniques for remote interference (RIM).
- Proposal 2.3 (Sec 2.1): Study mechanisms for inter-cell exchange of information to ensure timely handling of the inter-cell UE-to-UE CLI.