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KR-20260066801-A - Method and device for performing energy saving in a UE performing discontinuous reception

KR20260066801AKR 20260066801 AKR20260066801 AKR 20260066801AKR-20260066801-A

Abstract

The present disclosure relates to a method and device for enabling a user device (UE) (20) having a low-power wake-up signal receiver (LP-WUR) (254) to reduce its energy consumption during the discontinuous reception (DRX) active period of a DRX cycle.

Inventors

  • 샤 리킨
  • 푸쉬카르나 라자트
  • 곤잘레스 곤잘레스 다비드

Assignees

  • 아우모비오 저머니 게엠베하

Dates

Publication Date
20260512
Application Date
20241015
Priority Date
20231031

Claims (20)

  1. A method (70) for exchanging data in a wireless communication system, wherein the method is implemented by a wireless device (25) of the wireless communication system, the wireless device comprises a main radio (MR) unit (253) configured to exchange data with a radio access network (RAN) of the wireless communication system, and a low-power wake-up receiver (LP-WUR) (254) configured to monitor a wake-up signal transmitted by the RAN and trigger a transition to an active state of the MR unit in response to detecting the wake-up signal, the wireless device (25) comprises a discontinuous reception (DRX) cycle, the DRX cycle comprises a DRX active period during which the wireless device (25) can receive control data from the RAN via a physical downlink control channel (PDCCH), and a DRX inactive period during which the wireless device (25) does not perform PDCCH monitoring, the DRX active period comprises an active sub-period following an inactive sub-period, and the LP-WUR (254) during the DRX inactive period In response to detecting a wake-up signal, the method during the next DRX active period, - (S70) A step of performing wake-up signal monitoring by the LP-WUR (254) during the inactive sub-period while the MR unit is in a low-power state, - A method (70) comprising, in response to detecting a wake-up signal during the inactive subperiod, (S71) triggering a transition of the MR unit to the active state and (S72) performing PDCCH monitoring during the active subperiod.
  2. In claim 1, in response to not detecting a wake-up signal during the inactive subperiod, the MR unit is maintained in the low-power state during the active subperiod, method (70).
  3. In paragraph 2, in response to not detecting a wake-up signal during the inactive sub-period, the LP-WUR does not perform wake-up signal monitoring during the active period, method (70).
  4. A method (70) comprising, in any one of claims 1 to 3, (S74) receiving a DRX active period configuration defining the inactive sub-period and the active sub-period within the DRX active period.
  5. In paragraph 4, the method (70) wherein the DRX active period configuration is received from system information broadcast by the RAN and/or the DRX active period configuration is received from a radio resource control (RRC) reconfiguration message transmitted by the RAN.
  6. A method (70) in which, in any one of claims 1 to 5, if a wake-up signal is not detected during the DRX inactive period, the wireless device (25) does not perform PDCCH monitoring during the next DRX active period.
  7. A method (70) according to any one of claims 1 to 6, wherein the DRX active period comprises a plurality of active sub-periods and/or the DRX active period comprises a plurality of inactive sub-periods.
  8. A method (70) according to any one of claims 1 to 7, wherein the DRX active period begins with an active sub-period.
  9. A method (70) in which, in any one of claims 1 to 8, during the DRX inactive period, the MR unit is maintained in a low-power state different from the low-power state used during the inactive sub-period of the DRX active period.
  10. A wireless device (25) comprising at least one processor (250) and at least one memory (251) configured to perform a method (70) according to any one of claims 1 to 9.
  11. User equipment (UE) (20) including a wireless device according to paragraph 10.
  12. A method (60) for exchanging data in a wireless communication system, wherein the method is implemented by a base station (BS) (30) of a radio access network (RAN) of the wireless communication system, wherein the BS is configured to exchange data with a wireless device (25), wherein the wireless device includes a main radio (MR) unit (253) and a low-power wake-up receiver (LP-WUR) (254), wherein the LP-WUR is configured to detect a wake-up signal transmitted by the BS and to trigger a transition to an active state of the MR unit in response to detecting the wake-up signal transmitted by the BS, wherein the BS is configured as a discontinuous reception (DRX) cycle, wherein the DRX cycle includes a DRX active period during which the BS can transmit control data to the wireless device via a physical downlink control channel (PDCCH) and a DRX inactive period during which the BS does not transmit control data to the wireless device via the PDCCH, wherein the DRX active period is at least on inactive A method (60) comprising a sub-period and at least one active sub-period, wherein the BS is configured to transmit control data to the wireless device via the PDCCH only during the at least one active sub-period.
  13. In claim 12, the method (60) comprises the step of (S60) transmitting a wake-up signal to the wireless device during the inactive subperiod in response to determining that control data will be transmitted during the active subperiod following the inactive subperiod of the DRX active period.
  14. A method (60) further comprising, in response to determining that control data will be transmitted during the DRX active period in any one of claims 12 to 13, (S63) transmitting a wake-up signal to the wireless device during the DRX inactive period followed by the DRX active period.
  15. A method (60) according to any one of claims 12 to 14, comprising the step (S65) of transmitting a DRX active period configuration to the wireless device, wherein the DRX active period configuration defines the at least one inactive sub-period and the at least one active sub-period within the DRX active period.
  16. In paragraph 15, the method (60) wherein the DRX active period configuration is transmitted in system information broadcast by the RAN and/or the DRX active period configuration is transmitted in a radio resource control (RRC) reconfiguration message transmitted to the wireless device.
  17. A method (60) in any one of claims 12 to 16, wherein the DRX active period begins with an active sub-period.
  18. A base station (BS) (30) comprising at least one processor (300) and at least one memory (301) configured to perform a method (60) according to any one of claims 12 to 17.
  19. A wireless communication system comprising at least one base station (30) according to claim 18 and at least one user equipment (20) according to claim 11.
  20. A computer program product (252, 302) comprising instructions, wherein the instructions configure the at least one processor to perform a method (70) according to any one of claims 1 to 9 or a method (60) according to any one of claims 12 to 17 when executed by at least one processor.

Description

Method and device for performing energy saving in a UE performing discontinuous reception The present disclosure relates to a wireless communication system, and more specifically, to a method and device for saving energy on the side of user equipment (UE) of a wireless communication system. In 3GPP (Third Generation Partnership Project) wireless communication systems, discontinuous reception (DRX) was introduced to reduce energy consumption. Basically, in DRX, the UE periodically enters sleep during an asleep duration, when the PDCCH is not being monitored, before waking up during an awake duration to monitor the physical downlink control channel (PDCCH) for available downlink control data. The amount of energy that can be saved depends on how long and how often the UE remains in the sleep state. Naturally, the longer the UE stays in the sleep state, the greater the amount of energy saved. To improve energy savings in 5G or NR (New Radio) wireless communication systems without sacrificing latency, 3GPP intends to define a new architecture for UEs (see, for example, technical report [TR 38.869]). Basically, current UEs need to wake up periodically once every DRX cycle, and this dominates energy consumption during periods without signaling or data traffic. If the UE could wake up only when triggered, for example, only during paging, energy consumption could be dramatically reduced. As investigated by 3GPP, this is achieved by providing the UE with both a main radio (MR) unit and a low power wake-up receiver (LP-WUR). Basically, the MR unit corresponds to a 5G NR radio communication unit, and the LP-WUR corresponds to a radio communication unit used to monitor wake-up signals with low power consumption. When a wake-up signal is detected, the LP-WUR can trigger the MR unit, which can switch from a low-power state to an active state. The active state corresponds to a state in which the MR unit can exchange data with the radio access network (RAN) of the wireless communication system. The low-power state corresponds to any state in which the MR unit cannot exchange data with the RAN. The ‘low power’ state means that the average power consumption of the MR unit in the low power state is lower than the average power consumption of the MR unit in the active state (preferably significantly lower, for example, ten times or even a hundred times lower). A ‘low-power’ wake-up receiver means that the LP-WUR is used to receive the wake-up signal while the MR unit is in a low-power state. Of course, monitoring of the wake-up signal must be performed with low power consumption, and the average power consumption of the LP-WUR must be lower than its average power consumption when the MR unit is active (preferably significantly lower, for example, ten times or even a hundred times lower). Therefore, energy consumption is reduced by placing the MR unit in a low-power state (e.g., turned off). The MR unit does not need to be woken up periodically and can be woken up only when triggered by the LP-WUR. Since the LP-WUR can monitor the wake-up signal continuously or at least frequently, the MR unit can be woken up by the LP-WUR at any time, thereby enabling additional low latency. For example, LP-WUR may be used when the UE performs DRX. As previously described, DRX is based on a DRX cycle that includes a DRX active period during which the UE must wake up for the wake duration and a DRX inactive period during which the UE enters sleep for the sleep duration. Based on the DRX cycle, using LP-WUR allows the UE to be woken up for the next DRX active period only if a wake-up signal is detected during the DRX inactive period. If no wake-up signal is received during the DRX inactive period, the UE may skip the next DRX active period, and the MR unit may remain in a low-power state during the next DRX active period (without PDCCH monitoring). Therefore, LP-WUR can be used to wake up the UE during the DRX active period only when the RAN intends to transmit control data to the UE via PDCCH during the DRX active period. However, since the UE cannot know in advance when the RAN will transmit control data during the DRX active period, the UE must remain in the awake state for the entire awake duration of the DRX active period. Therefore, there is a need to further reduce energy consumption. The present disclosure aims to improve this situation. In particular, the present disclosure aims to solve at least some of the limitations of the prior art discussed above. In particular, the present disclosure aims to propose a solution for reducing the duration for which an MR unit must remain active within the DRX active period of a DRX cycle. According to a first aspect, the present disclosure relates to a method for exchanging data in a wireless communication system, wherein the method is implemented by a wireless device of the wireless communication system, the wireless device comprises a main radio (MR) unit configured to exchange data with a radio a