Selective wake-up signal monitoring
Methods and apparatus are described for adapting wake-up signal monitoring to optimize power saving performance. In one embodiment, a UE can be configured to selectively skip WUS monitoring based on a current UE context. In another embodiment, WUS/PDCCH monitoring and/or other UE procedure can be adapted based on a statistic related to the wake-up signals transmitted by the base station to the UE.
1. A method of wake-up signal (WUS) monitoring implemented by a user equipment (UE) operating in a discontinuous reception (DRX) mode, the method comprising:
selectively monitoring a wake-up signal monitoring occasion preceding the OnDuration of a DRX cycle for a wake-up signal depending on predetermined criterion relating to expected data traffic, wherein selectively monitoring the wake-up signal monitoring occasion comprises skipping monitoring of the wake-up signal monitoring occasion responsive to determining that data traffic is expected during the OnDuration of the DRX cycle; and
waking during a corresponding OnDuration of the DRX cycle and monitoring the downlink control channel when monitoring of the WUS monitoring occasion is skipped.
2. The method of claim 1 , further comprising monitoring a downlink control channel during a next OnDuration of the DRX cycle when a wake-up signal is detected during the wake-up signal monitoring occasion.
3. The method of claim 1 , wherein the expected data traffic comprises downlink data traffic.
4. The method of claim 1 , wherein the expected data traffic comprises uplink data traffic.
5. The method of claim 1 , wherein the UE determines that data traffic is expected based on a traffic pattern of an application.
6. The method of claim 1 , wherein the UE determines that data traffic is expected based on a scheduled download.
7. The method of claim 1 , wherein the selectively monitoring the wake-up signal monitoring occasion comprises skipping monitoring of the wake-up signal monitoring occasion responsive to a reception condition.
8. The method of claim 7 :
wherein the reception condition comprises a channel quality; and
wherein monitoring of the wake-up signal monitoring occasion is skipped when the channel quality is below a threshold.
9. The method of claim 7 :
wherein the reception condition comprises a velocity or mobility of the UE; and
wherein monitoring of the wake-up signal monitoring occasion is skipped when the mobility or velocity of the UE is greater than a threshold.
10. The method of claim 7 , wherein the reception condition comprises a Transmit Configuration Indicator (TCI) state of the UE.
11. The method of claim 1 , wherein selectively monitoring a wake-up signal monitoring occasion comprises skipping monitoring of the wake-up signal monitoring occasion depending on a UE configuration.
12. The method of claim 11 , wherein the UE configuration is a DRX configuration, WUS configuration, or both.
13. The method of claim 12 , wherein wake-up signal monitoring is skipped and the downlink control channel is monitored:
when a length of a current DRX cycle period is less than a predetermined length;
when a current DRX cycle period is greater than a periodicity of expected data traffic;
when a length of an OnDuration of a current DRX cycle is less than a predetermined length; or
when an offset between the wake-up signal monitoring occasion and start of the OnDuration of the DRX cycle is greater than a threshold.
14. The method of claim 11 , wherein wake-up signal monitoring is skipped and the downlink control channel is monitored:
depending on a measurement configuration of the UE;
when the UE is connected to an external power supply; or
responsive to determining that a reference signal is expected before the OnDuration.
15. The method of claim 1 , wherein selectively monitoring a wake-up signal monitoring occasion comprises skipping monitoring of the wake-up signal monitoring occasion dependent on a power saving metric.
16. The method of claim 1 , wherein wake-up signal monitoring is skipped and the downlink control channel is monitored responsive to receipt of an indication from a base station.
17. The method of claim 1 , wherein the method comprises selecting a reception configuration for the OnDuration depending on historical usage of the reception configuration.
18. A user equipment (UE) in a wireless communication network comprising:
communication circuitry for communicating with a wireless communication network;
processing circuitry operative to:
selectively monitor a wake-up signal monitoring occasion preceding the OnDuration of a DRX cycle for a wake-up signal (WUS) depending on predetermined criterion relating to expected data traffic, wherein selectively monitoring the wake-up signal monitoring occasion comprises skipping monitoring of the wake-up signal monitoring occasion responsive to determining that data traffic is expected during the OnDuration of the DRX cycle; and
wake during a corresponding OnDuration of the DRX cycle and monitor the downlink control channel when monitoring of the WUS monitoring occasion is skipped.