Low-power wake up radio operation in wireless communication
A user equipment (UE) is configured to enter a radio resource control (RRC) state with a base station wherein network operations are performed using a main radio (MR), receive a first set of parameters from the base station for wakeup radio (WUR) state operation wherein the UE enables a WUR and powers down the MR to an off or deep sleep state, the first set of parameters including a parameter enabling the WUR state operation and a configuration of WUR reference signaling (WUR-RS), receive a second set of parameters from the base station for WUR setup and a WUR signal (WUR-S) configuration and enter the WUR state from the RRC state, wherein, while in the WUR state, the UE performs uses the WUR including at least one of monitoring for the WUR-S, measuring the WUR-RS, or implementing a WUR discontinuous reception (DRX) cycle for WUR-S and WUR-RS signal monitoring.
1 . A processor of a base station configured to perform operations comprising:
entering a radio resource control (RRC) state with a user equipment (UE);
transmitting a first set of parameters to the UE for a wakeup radio (WUR) state, the first set of parameters including a parameter enabling the WUR state for the UE, a configuration for a WUR reference signal (WUR-RS) and a trigger condition for the UE to switch from the WUR state to the RRC State, wherein the trigger condition is based on a reference signal received power (RSRP) threshold; and
transmitting a second set of parameters to the UE for a WUR setup and a configuration for a WUR signal (WUR-S).
2 . The processor of claim 1 , wherein the trigger condition comprises a signal energy threshold for WUR-RS measurements, wherein, when a signal energy is below the signal energy threshold, the UE switches from the WUR state to the RRC state.
3 . The processor of claim 1 , wherein the first set of parameters are transmitted in a system information block (SIB) or via dedicated RRC signaling.
4 . The processor of claim 1 , wherein the configuration for the WUR-S additionally includes a sequence ID.
5 . The processor of claim 1 , wherein the operations further comprise:
receiving a WUR request from the UE to request the base station to enable the WUR state for the UE, wherein the WUR request includes assistance information used by the base station to determine whether the WUR state is to be enabled.
6 . The processor of claim 1 , wherein the operations further comprise:
receiving an acknowledgement for reception of the second set of parameters, wherein the acknowledgement is HARQ-ACK feedback transmitted over a physical uplink control channel (PUCCH) in slot n+k, wherein the second set of parameters from the base station is received over a physical downlink shared channel (PDSCH) in slot n and a value of k is hard-encoded in specification.
7 . The processor of claim 1 , wherein the operations further comprise:
configuring the UE with a WUR-RS based measurement report, wherein the WUR-RS based measurement report is transmitted by the UE based on a trigger event or periodically.
8 . The processor of claim 7 , wherein the operations further comprise:
receiving the WUR-RS based measurement report, the measurement report including WUR-RS measurement results and an indication of the trigger event; and
receiving a WUR release request from the UE using a stored radio network temporary identifier (RNTI) value.
9 . The processor of claim 8 , wherein the operations further comprise:
transmitting a WUR mode release message confirming a transition from the WUR state to the RRC state; and
transmitting a latest RRC configuration via dedicated RRC signaling.
10 . The processor of claim 9 , wherein the operations further comprise:
receiving a WUR request from the UE, the WUR request comprising WUR-RS-based measurement results; and
transmitting a WUR setup message to the UE.
11 . The processor of claim 1 , wherein the operations further comprise:
transmitting the WUR-S in a groupcast to wake up a set of UEs.
12 . The processor of claim 1 , wherein the WUR-S is dedicatedly associated with the UE.
13 . The processor of claim 12 , wherein the WUR-S is determined based on a unique UE ID.
14 . The processor of claim 12 , wherein the WUR-S is assigned by the base station through dedicated RRC signaling.
15 . The processor of claim 1 , wherein the operations further comprise:
transmitting a transmission configuration indicator (TCI) state for the WUR-S and the WUR-RS.
16 . The processor of claim 1 , wherein the operations further comprise:
receiving, from the UE, an acknowledgement of a WUR-S reception.
17 . The processor of claim 16 , wherein the acknowledgement is received in a Msg3 payload or using a dedicated logical channel ID of a corresponding medium access layer (MAC) service data unit (SDU).
18 . The processor of claim 16 , wherein the acknowledgement is received over a physical uplink control channel (PUCCH) resource configured for the UE or determined implicitly by the UE.