R1-2509147
discussion
Energy efficiency for 6GR
From MediaTek
Summary
MediaTek's Tdoc R1-2509147 for the 6G Radio study item presents 33 proposals and 37 observations focused on energy efficiency evaluation methodology, cell-specific designs, and UE/group-specific energy saving schemes. The document provides a comprehensive framework including evaluation metrics, BS/UE power consumption model updates, and specific technical designs like LP-TX/RX, WUR-assisted SSSG switching, and lean CSI frameworks.
Position
MediaTek proposes defining energy efficiency metrics based on bits per Joule with joint BS/UE metrics using balanced weighting parameters (α,β) = (1,1). They propose using BS Category 2 as the baseline for 6GR evaluation and introduce an LP-TX/RX concept with additional scaling factor for reduced antenna count operation targeting SSB, PRACH, and UL-WUS. They propose deprioritizing cell DTX/DRX for all RRC states, arguing that on-demand SIB1/SSB requests via UL-WUS and other alternatives provide similar NES gains. For UE designs, they propose studying WUR-assisted SSSG switching with up to three SSSGs, early data indication via 2-stage DCI, and BWP-lite based joint multi-domain adaptation achieving 38-87% BS EE improvement and 20-54% UE EE improvement. They propose studying lean CSI frameworks with reduced CSI-RS/SRS ports, traffic-scaled overhead, and direct channel feedback for minimizing compression loss.
Key proposals
- Proposal 1 (Sec 2.1): Define the energy efficiency metric as bits per Joule, with numerator as total bits successfully delivered and denominator based on BS or UE power consumption model.
- Proposal 5 (Sec 2.2): For 6GR energy efficiency evaluation, at least evaluate empty (L=0), low (0<L≤15%), light (15%<L≤30%), and medium (30%<L≤50%) load cases.
- Proposal 9 (Sec 2.3.2): Adopt an additional scaling factor on top of existing scaling factor to represent further energy saving from activating only a subset of TRxRUs for BS LP-TX/RX.
- Proposal 11 (Sec 2.4.1): Update scaling w.r.t. bandwidth adaptation for 6GR by taking into account the allowed adaptation time, with different scaling values depending on whether adaptation time of at least 2ms is allowed.
- Proposal 17 (Sec 3.1.2): Study optimal SSB transmit design with LP-TX/RX, SSB repetition, and 40ms periodicity to achieve BS EE improvement without noticeably increasing UE access latency.
- Proposal 20 (Sec 3.2): Support standalone OD-SIB1 request via UL-WUS without assistance from Cell-A.
- Proposal 24 (Sec 3.4): Flexible paging occasion w.r.t. WUS based paging indication is supported for 6G Day 1.
- Proposal 26 (Sec 3.5): Deprioritize cell DTX/DRX in 6GR study for all RRC states.
- Proposal 27 (Sec 3.6): Study the mapping of multiple aggregated carriers to the same cell for NES for 6G.
- Proposal 29 (Sec 4.2): Study SSSG switching enhancement integrating WUS/WUR benefits for UE power saving.
- Proposal 30 (Sec 4.3): Study early data indication mechanisms for UE power consumption optimization regarding data availability/amount, while preventing different scheduling information provision timing.
- Proposal 31 (Sec 4.4): Study and evaluate enhanced BW adaptation for 6GR EE improvement regarding UE-specific indication, fast and robust L1 indication, and cell/group-wise indication.
- Proposal 32 (Sec 4.5): Pursue lean CSI frameworks in time and spatial domains to reduce 6G channel information acquisition energy consumption through reduced CSI-RS/SRS ports, overhead scaling with traffic loading, and minimized feedback compression/quantization loss.
- Proposal 33 (Sec 4.6): Study and evaluate UE feedback enhancement for 6G EE improvement including reuse of NR UAI framework and additional EE feedback for joint BS and UE power saving.