R1-2601900
discussion
Other physical layer signals, channels and procedure
From Ericsson
Summary
Ericsson presents 6 proposals and 5 observations across 6G physical layer topics: cross-link interference (CLI) reuse from Rel-19 with potential L1/L3 unification, remote interference management (RIM) prioritizing Framework-1 with 6G-specific set ID embedding, contention-based multi-bit scheduling requests (CB-BSR) with DMRS design study, and interference identification requiring new UE measurements for classification.
Position
Ericsson proposes reusing Rel-19 BS-to-BS and UE-to-UE CLI enhancements as the 6GR baseline and supports studying feasibility of BS flexibly configuring both L3 (MeasObjectCLI) and L1 (CSI-ResourceConfig) UE-to-UE CLI measurement configuration and reporting, moving toward a potentially unified CLI framework separate from the CSI framework. They require embedding 6GR-specific information in the RIM set ID to enable differentiation of remote interference scenarios across 5G and 6G networks and prioritize RIM Framework-1 over FW-0 and backhaul-based FWs 2.1/2.2 to simplify design and interoperability. They propose studying contention-based multi-bit buffer-status reports (CB-BSR) as an alternative to single-bit scheduling requests, demonstrating via simulations that allocating different DMRS ports or scrambling sequences can avoid excessive BLER when multiple UEs select the same contention resource. They propose studying new UE measurements and related procedures for downlink interference classification to distinguish intra-system, external unintentional, and deliberate jamming interference types.
Key proposals
- Proposal 1 (Sec 2): Reuse Rel-19 BS-to-BS and UE-to-UE CLI enhancements for 6GR as the baseline.
- Proposal 2 (Sec 2): Study the necessity and feasibility of BS flexibly configuring both L3 and L1 UE-to-UE CLI measurement configuration and reporting.
- Proposal 3 (Sec 3): Reuse the RIM-RS type 1 and type 2 structures specified for 5G NR for 6GR remote interference management, considering that remote interference may originate from either 5G or 6G cells, and enable embedding of 6GR-specific information in the RIM set ID.
- Proposal 4 (Sec 3): To simplify 6G RIM design and inter-operability across network vendors, RIM FW-1 should be prioritized for the 6G RIM design.
- Proposal 5 (Sec 4): Study support for multi-bit contention-based reports that include detailed information about the buffer-status as an alternative to dedicated single-bit scheduling requests.
- Proposal 6 (Sec 5): Study the need for new UE measurements and potential related procedures to enable interference classification in the downlink for 6GR.
- Observation 1 (Sec 3): 6GR-specific information needs to be embedded in the RIM set ID to support identification, coordination, and differentiation of remote interference scenarios across 5G and 6G networks.
- Observation 2 (Sec 3): RIM FW-0 relies on manual intervention for start/stop of RS transmission and mitigation.
- Observation 3 (Sec 3): RIM FWs 2.1 and 2.2 rely on backhaul-based point-to-point signaling, incurring significant overhead and scalability challenges due to the inherently one-to-many relationships between aggressor and victim cells.
- Observation 4 (Sec 4): Contention-based operation can avoid excessive BLER by allocating different DMRS ports and/or scrambling sequences.
- Observation 5 (Sec 4): Study DMRS design for contention-based uplink transmissions of CB-BSR, including DMRS port/sequence configurations, their orthogonality vs. multiplicity trade-offs, when multiple UEs select the same contention resource.