R1-2600127
discussion
Discussion on uplink WUS and operation for 6GR
From Spreadtrum
Summary
This Spreadtrum contribution provides views on uplink wake-up signal (UL WUS) design and on-demand system information/SSB operation for 6G, containing 5 proposals and 5 observations. It supports a unified UL WUS design and proposes immediate adoption of on-demand SIBx and on-demand SSB for SCell from 5G NR legacy, while recommending delayed discussion on UL WUS for on-demand SIB1 and SSB in idle mode pending progress in other agenda items.
Position
Spreadtrum proposes a single unified design for UL WUS to meet different on-demand signal requirements in 6G. They require on-demand SIBx to be supported from 6G Day 1 using 5G NR legacy mechanisms (PRACH with dedicated preambles/resources for UL WUS, RAR MAC PDU subheader with RAPID for NW acknowledgement, Msg3 carrying system information request, or RRC signaling for connected UEs), citing successful 5G commercialization and limited negative UE impact. They propose delaying UL WUS discussion for on-demand SIB1 and on-demand SSB in idle state until feasibility and necessity are evaluated in AI 10.5.1.1, referencing the FL guidance from R1-2509594. They support immediate adoption of on-demand SSB for SCell with NW triggering (no UL WUS) using the Rel-19 legacy solution, characterizing it as a good balance between NW energy efficiency and UE performance for synchronization and measurement purposes.
Key proposals
- Proposal 1 (Sec 2): Support to strive one unified design of UL WUS.
- Proposal 2 (Sec 2): Support on-demand SIBx in 6GR Day 1. The legacy solution in 5G NR can be as the starting point.
- Proposal 3 (Sec 2): For on-demand SSB1 in idle state, the justification is needed. Suggest to delay the discussion of UL WUS for on-demand SIB1 in idle state until there are some progresses in AI 10.5.1.1.
- Proposal 4 (Sec 2): On-demand SSB for scell can be considered in 6GR Day1. The legacy mechanism of NW triggering in 5G NR can be considered as the starting point.
- Proposal 5 (Sec 2): For on-demand SSB in idle state, the justification is needed. Suggest to delay the discussion of UL WUS for on-demand SSB in idle state until there are some progresses in AI 10.5.1.1.