R1-2601904
discussion
Uplink WUS and operation
From Ericsson
Summary
Ericsson presents 11 Observations and 8 Proposals arguing that uplink WUS (Wake-Up Signal) is largely unnecessary and infeasible for most deployment scenarios, recommending that only Deployment Scenario #1b be further studied in the context of on-demand SIB1 under agenda item 10.5.1.
Position
Ericsson questions the necessity of UL WUS discussions in agenda item 10.6.2 by arguing that on-demand sync signals and on-demand SIB1 are already covered in other agenda items (AI 10.5.1.1, 10.5.1.2) and NES power models are treated in AI 10.4. They oppose DS#1a and DS#2a on fundamental grounds, citing inability to achieve time-frequency synchronization, lack of WUS configuration and transmission parameters, inability to identify the cell or determine UL transmit power, and violation of the principle that the network is responsible for resource allocation. They propose that DS#1b be redirected to agenda item 10.5.1 for study in the context of on-demand SIB1, while identifying the main challenge as providing UL WUS configuration—potentially hundreds of bits—prior to SIB1 reception. They de-prioritize DS#2b due to marginal NES gain of around 4% with 160 ms SSB periodicity and propose that any 6G evaluations use a baseline with longer SSB periodicity and clustered SI/common transmissions. They oppose DS#1c and DS#2c, arguing that any UE with poor implementation could exploit UL WUS for additional sync signal transmissions, which is not resource efficient and significantly increases network energy consumption.
Key proposals
- Proposal 1 (Sec 2.1.1): A UE blindly transmitting UL WUS towards an assumed sleeping cell violates fundamental principles and should be prohibited.
- Proposal 2 (Sec 3.1.1): "DS#1a: prior to UL WUS, nothing transmitted on the standalone cell" is not further studied.
- Proposal 3 (Sec 3.1.2): DS#1b to be further studied in agenda item 10.5.1 in the context of on-demand SIB1.
- Proposal 4 (Sec 3.1.3): DS#1c for UL WUS is not further considered.
- Proposal 5 (Sec 3.2.1): "DS#2a: prior to UL WUS, nothing transmitted on cell/carrier #2" is not further studied.
- Proposal 6 (Sec 3.2.2): For evaluations of on-demand SIB1, a 6G baseline configuration should be considered where e.g., SSB is transmitted with longer periodicity and SI and other common transmissions are clustered.
- Proposal 7 (Sec 3.2.2): DS#2b is de-prioritized due to marginal NES gain and being limited to only non-standalone scenarios.
- Proposal 8 (Sec 3.2.3): DS#2c for UL WUS is not further considered.