R1-2601863
discussion
Aspects of integration with communication
From NEC
Summary
This NEC contribution to the 6G Study Item on Integrated Sensing and Communication (ISAC) provides 16 proposals and 16 observations across four areas: sensing-communication integration requirements, reference signal design, and PHY procedures/measurements. The document systematically addresses sensing modes, resource allocation, frame structure, power control, and signal design for the 6G radio physical layer.
Position
NEC proposes studying all six sensing modes (TRP-TRP bistatic, TRP monostatic, TRP-UE bistatic, UE-TRP bistatic, UE-UE bistatic, UE monostatic) plus multi-static sensing for comprehensive integration requirement analysis. They propose reusing PRS and SRS with enhancements (expanded symbol counts to values of 1 or 8, new comb sizes {1,3,8}) as a starting point, and include DMRS as a sensing signal option citing its dense allocation, Doppler robustness, and multi-antenna support for high-mobility use cases like V2X, UAV tracking, and high-speed rail monitoring. They prioritize TDM-based resource allocation via a dedicated sensing resource pool, analogous to sidelink resource pool design within UL communication resources. For mono-static sensing, they propose a gap design after the sensing signal where gap length and sensing symbol length are determined by the maximum sensing range of the sensing node. They identify that ISAC path loss must be calculated on a per-path or per-path-group basis associated with the sensing target/object, distinguishing valid echo paths reflected by the target from invalid environment reflections, and propose a new sensing-specific PHR procedure fused with the existing communication PHR.
Key proposals
- Proposal 1 (Sec Overview of Sensing-Communication Integration Requirements): Support the study of all six sensing modes and multi-static sensing.
- Proposal 5 (Sec Reference signal design > Shared Reference Signals): Study reusing the PRS and SRS with enhancements as a start point for sensing signal design.
- Proposal 7 (Sec Reference signal design > Dedicated Reference Signals): Study strategies for multiplexing rules for allocating dedicated sensing reference signals without reducing communication throughput.
- Proposal 9 (Sec PHY Procedure, Measurement and Reporting): Study how to integrate sensing processing into the existing PHY chain.
- Proposal 10 (Sec PHY Procedure, Measurement and Reporting): Prioritize TDM-based resource allocation (e.g., sensing resource pool) between sensing and communication.
- Proposal 11 (Sec PHY Procedure, Measurement and Reporting): Study sensing node discovery mechanism, including RAN node discovery and UE node discovery.
- Proposal 12 (Sec PHY Procedure, Measurement and Reporting): Study beam management solutions for ISAC that tackle the above key challenges.
- Proposal 13 (Sec PHY Procedure, Measurement and Reporting): Study sensing link maintenance schemes for ISAC (sensing link failure, detection and recovery).
- Proposal 14 (Sec PHY Procedure, Measurement and Reporting): Study power control schemes for ISAC sensing signals (adapting to sensing coverage and interference suppression requirements).
- Proposal 15 (Sec PHY Procedure, Measurement and Reporting): Study path loss determination for sensing signal associated with the path or path group which reflected from a given target/object.
- Proposal 16 (Sec PHY Procedure, Measurement and Reporting): Study sensing Power Headroom Report (PHR) procedure and its fusion with communication PHR.
- Proposal 3 (Sec Overview of Sensing-Communication Integration Requirements): The study of the longer cyclic prefix should consider the frame structure conflicts between communication and sensing symbols within the same slot.
- Proposal 6 (Sec Reference signal design > Shared Reference Signals): Include DMRS as one of the feasible options of sensing signal design.
- Proposal 8 (Sec Reference signal design > Dedicated Reference Signals): Study sensing signal design with a gap after the sensing signal for mono-static sensing mode, wherein the gap length and sensing signal length are associated with the maximum sensing range of the sensing node.