Method and apparatus for performing energy saving when ue performs discontinuous reception

Abstract

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

Description

Technical Field

[0001] This disclosure relates to wireless communication systems, and more specifically to methods and apparatus for saving energy on the user equipment (UE) side of a wireless communication system. Background Technology

[0002] To reduce energy consumption, Discontinuous Reception (DRX) has been introduced in 3GPP (3rd Generation Partnership Project) wireless communication systems. Essentially, in DRX, the UE periodically enters a sleep period of sustained duration, during which it does not monitor the Physical Downlink Control Channel (PDCCH), and then wakes up during a wake-up period to monitor the PDCCH for possible downlink control data. The amount of energy saved depends on how long and how frequently the UE remains in sleep mode. Naturally, the longer the UE remains in sleep mode, the greater the energy savings.

[0003] In order to enhance energy efficiency without sacrificing latency in 5G or New Radio (NR) wireless communication systems, 3GPP is willing to define a new architecture for UEs (see, for example, Technical Report TR 38.869).

[0004] Essentially, current UEs need to be woken up periodically once per DRX cycle, which constitutes a major energy consumption during periods without signaling or data traffic. Energy consumption could be significantly reduced if UEs could only be woken up when triggered (e.g., during paging). As studied by 3GPP, this is achieved by providing the UE with both a primary radio (MR) unit and a low-power wake-up receiver (LP-WUR).

[0005] Basically, the MR unit corresponds to the 5G NR wireless communication unit, and the LP-WUR corresponds to the wireless communication unit used for low-power monitoring of wake-up signals. Once a wake-up signal is detected, the LP-WUR can trigger the MR unit, which can then transition from a low-power state to an active state.

[0006] The active state corresponds to the state in which the MR unit exchanges 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.

[0007] "Low power" means that the average power consumption of the MR cell in the low power state is lower than (and preferably significantly lower, for example, ten times or even a hundred times lower) the average power consumption of the MR cell in the active state.

[0008] A "low-power" wake-up receiver means that the LP-WUR is used to receive wake-up signals when the MR unit is in a low-power state. Of course, the monitoring of the wake-up signal should be performed at low power, and therefore, the average power consumption of the LP-WUR should be lower than (and preferably significantly lower, for example, ten or even a hundred times lower) the average power consumption of the MR unit in the active state.

[0009] Therefore, energy consumption is reduced by placing the MR unit in a low-power state (e.g., off). The MR unit does not need to be periodically woken up and can be woken up only when triggered by the LP-WUR. Since the LP-WUR can continuously or at least frequently monitor the wake-up signal, the MR unit can potentially be woken up by the LP-WUR at any time, thereby further achieving low latency.

[0010] For example, LP-WUR can be used when the UE performs DRX. As discussed above, DRX is based on a DRX cycle, which includes a DRX active period (during which the UE needs to wake up for the wake-up duration) and a DRX inactive period (during which the UE enters sleep for the sleep duration). Based on this DRX cycle, LP-WUR can only be used to wake up the UE in the next DRX active period 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 can skip the next DRX active period, and the MR unit can remain in a low-power state (without monitoring the PDCCH) during the next DRX active period.

[0011] Therefore, LP-WUR can only be used to wake up the UE during a DRX active period if the RAN intends to send control data to the UE via PDCCH. However, the UE needs to remain awake for the entire wake-up duration of the DRX active period because the UE does not know in advance when the RAN will send control data during the DRX active period.

[0012] Therefore, it is necessary to further reduce energy consumption. Summary of the Invention

[0013] This disclosure aims to improve this situation. In particular, this disclosure aims to address at least some of the limitations of the prior art discussed above. Specifically, this disclosure aims to provide a solution for reducing the duration during which MR units need to remain active during the DRX activity period of a DRX cycle.

[0014] According to a first aspect, this disclosure relates to a method for exchanging data in a wireless communication system, the method being implemented by a wireless device of the wireless communication system, wherein the wireless device includes: a master radio (MR) unit configured to exchange data with a radio access network (RAN) of the wireless communication system; and a low-power wake-up receiver (LP-WUR) configured to monitor a wake-up signal transmitted by the RAN and trigger a transition of the MR unit to an active state in response to detecting the wake-up signal, wherein the wireless device is configured to have a discontinuous reception DRX cycle, wherein the DRX cycle includes a DRX active period and a DRX inactive period, during which the wireless device may receive control data from the RAN via a physical downlink control channel (PDCCH), and during the DRX inactive period, the wireless device does not perform PDCCH monitoring, wherein the DRX active period includes an inactive sub-period and a subsequent active sub-period, and wherein in response to the LP-WUR detecting a wake-up signal during the DRX inactive period, the method includes during the subsequent DRX active period:

[0015] - Wake-up signal monitoring is performed by LP-WUR during inactive sub-periods, during which the MR unit is in a low-power state.

[0016] - In response to the detection of a wake-up signal during the inactive sub-period: trigger the transition of the MR unit to the active state, and perform PDCCH monitoring during the active sub-period.

[0017] In some embodiments, the method according to the first aspect may further include one or more of the following optional features, considered individually or in any technically possible combination.

[0018] In some embodiments of the method according to the first aspect, in response to the absence of a wake-up signal during the inactive sub-period, the MR unit maintains the low-power state during the active sub-period.

[0019] In some embodiments of the method according to the first aspect, in response to the absence of a wake-up signal during the inactive sub-period, the LP-WUR does not perform wake-up signal monitoring during the active period.

[0020] In some embodiments, the method according to the first aspect includes receiving a DRX activity period configuration, the DRX activity period configuration defining the inactive sub-period and the active sub-period within the DRX activity period.

[0021] In some embodiments of the method according to the first aspect, the DRX activity period configuration is received in system information broadcast by the RAN, and / or in a Radio Resource Control (RRC) reconfiguration message sent by the RAN.

[0022] In some embodiments of the method according to the first aspect, if no wake-up signal is detected during a DRX inactivity period, the wireless device does not perform PDCCH monitoring during a subsequent DRX activity period.

[0023] In some embodiments of the method according to the first aspect, the DRX active period includes multiple active sub-periods, and / or the DRX active period includes multiple inactive sub-periods.

[0024] In some embodiments of the method according to the first aspect, the DRX activity period begins with an activity sub-period.

[0025] In some embodiments of the method according to the first aspect, during the DRX inactivity period, the MR unit is maintained in a low-power state that is different from the low-power state used during the inactivity sub-period of the DRX activity period.

[0026] According to a second aspect, this disclosure relates to a wireless device including at least one memory and at least one processor configured to perform a method according to any embodiment of the first aspect.

[0027] According to a third aspect, this disclosure relates to a user equipment (UE) that includes a wireless means according to any one of the embodiments of this disclosure.

[0028] According to a fourth aspect, this disclosure relates to a method for exchanging data in a wireless communication system, the method being implemented by a base station (BS) of a radio access network (RAN) of the wireless communication system, wherein the BS is configured to exchange data with a wireless device, wherein the wireless device includes a main radio (MR) unit and a low-power wake-up receiver (LP-WUR), wherein the LP-WUR is configured to detect a wake-up signal transmitted by the BS and, in response to detecting the wake-up signal transmitted by the BS, trigger a transition of the MR unit to an active state, wherein the BS is configured to have a discontinuous reception DRX cycle, wherein the DRX cycle includes a DRX active period and a DRX inactive period, wherein during the DRX active period, the BS may transmit control data to the wireless device via a physical downlink control channel (PDCCH), and during the DRX inactive period, the BS does not transmit control data to the wireless device via the PDCCH, wherein the DRX active period includes at least one inactive sub-period and at least one active sub-period, and 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.

[0029] In some embodiments, the method according to the fourth aspect may further include one or more of the following optional features, considered individually or in any technically possible combination.

[0030] In some embodiments, the method according to the fourth aspect includes: in response to determining that control data is to be transmitted during an active sub-period following an inactive sub-period of the DRX active period, sending a wake-up signal to the wireless device during the inactive sub-period.

[0031] In some embodiments, the method according to the fourth aspect includes sending a wake-up signal to the wireless device during a DRX inactivity period prior to the DRX active period in response to determining that control data will be sent during a DRX active period.

[0032] In some embodiments, the method according to the fourth aspect includes sending a DRX activity period configuration to the wireless device, wherein the DRX activity period configuration defines the at least one inactive sub-period and the at least one active sub-period within the DRX activity period.

[0033] In some embodiments of the method according to the fourth aspect, the DRX activity period configuration is sent in system information broadcast by the RAN, and / or the DRX activity period configuration is sent in a Radio Resource Control (RRC) reconfiguration message sent to the radio device.

[0034] In some embodiments of the method according to the fourth aspect, the DRX activity period begins with an activity sub-period.

[0035] According to a fifth aspect, this disclosure relates to a base station (BS) including at least one memory and at least one processor configured to perform a method according to any embodiment of the fourth aspect.

[0036] According to a sixth aspect, this disclosure relates to a wireless communication system including at least one base station according to any embodiment of the present disclosure and at least one user equipment according to any embodiment of the present disclosure.

[0037] According to a seventh aspect, this disclosure relates to a computer program product including instructions that, when executed by at least one processor, configure the at least one processor to perform a method for exchanging data according to any embodiment of the present disclosure. The computer program product may use any programming language and may be in the form of source code, object code, or any intermediate form between source code and object code, such as a partially compiled form, or any other desired form.

[0038] According to an eighth aspect, this disclosure relates to a (non-transitory) computer-readable storage medium including instructions that, when executed by at least one processor, configure the at least one processor to perform a method for sending control messages according to any embodiment of the present disclosure. Attached Figure Description

[0039] The invention will be better understood after reading the following description, which is given by way of non-limiting example and with reference to the accompanying drawings, which illustrate:

[0040] - Figure 1 : A schematic representation of an example of a wireless communication system including a BS and a UE.

[0041] - Figure 2 : A schematic representation of an example of a wireless device,

[0042] - Figure 3 : A schematic representation of a BS example

[0043] - Figure 4 : An illustrative representation of examples of DRX activity period configurations.

[0044] - Figure 5 : This shows a schematic representation of the operation of the wireless device during the DRX cycle.

[0045] - Figure 6 and Figure 7 : Flowcharts showing examples of methods for exchanging data implemented by the wireless devices of the BS and UE, respectively.

[0046] In these figures, the same reference numerals in each figure denote the same or similar elements. For clarity, unless otherwise explicitly stated, the elements shown are not drawn to scale. Detailed Implementation

[0047] The detailed description set forth below with reference to the accompanying drawings is intended as a description of various configurations and is not intended to represent the only configuration in which the concepts described herein can be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. For example, although 3GPP terms from, for example, 5G NR may be used in this disclosure to exemplify embodiments herein, this should not be considered as limiting the scope of this disclosure.

[0048] Generally, unless a different meaning is clearly given and / or implied from the context of the use of the term, all terms used herein shall be interpreted according to their common meaning in the relevant art. Unless otherwise expressly stated, all references to an element, apparatus, component, member, step, etc., shall be openly interpreted as referring to at least one instance of that element, apparatus, component, member, step, etc. Furthermore, the order of steps of any method disclosed herein, particularly the order of steps in the figures, is provided for illustrative purposes only and is not intended to limit the disclosure. The same steps may be applied in a different order, and / or in all or part of steps performed in parallel or in combination, unless explicitly stated that a step follows or precedes another step, and / or where an implicit step must follow or precede another step. Additionally, in the figures, steps indicated by dashed lines are considered optional for the embodiments represented in the figures. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, as long as applicable. Similarly, any advantage of any of the embodiments may be applied to any other embodiment, and vice versa. Other objectives, features, and advantages of the appended embodiments will become apparent from the following description.

[0049] Figure 1 The illustration depicts an example of a wireless communication system, which could be, for example, a 5G NR wireless communication system. More specifically, Figure 1 This refers to the RAN of the wireless communication system, which is used to exchange data with UE 20 via radio signals. For example, the RAN can send data to UE 20 (downlink DL), such as data received from the core network (CN, not shown in the figure). The RAN can also receive data from UE 20 (uplink UL), which can be forwarded to the CN.

[0050] exist Figure 1In the example shown, the RAN includes one base station BS 30. Of course, the RAN can include more than one BS 30 to increase the coverage of the wireless communication system. Depending on the implemented wireless communication standard, each of these BSs can be referred to as an NB, eNodeB (or eNB), gNodeB (or gNB in ​​the case of a 5G NR wireless communication system), access point, etc.

[0051] exist Figure 1 In the example shown, two UEs 20 are represented. UE 20 is located within the coverage area 31 of BS 30. The coverage area 31 of BS 30 corresponds, for example, to an area where the UE can decode the PDCCH transmitted by BS 30.

[0052] Figure 2 An example of a wireless device 25 suitable for implementing any of the methods discussed in this disclosure at the UE 20 is illustrated schematically. Essentially, the wireless device 25 corresponds to equipment that provides wireless connectivity to a RAN of a wireless communication system and can be used to exchange data with that RAN.

[0053] Such a wireless device 25 can be included in the UE 20, such as Figure 2 As shown. UE 20 can be, for example, a cellular phone, wireless modem, wireless communication device, handheld device, laptop computer, etc. UE 20 can also be an Internet of Things (IoT) device, such as a wireless camera, smart sensor, smart meter, smart glasses, (manned or unmanned) vehicle, GPS device, etc., or any other device that can run applications that require exchanging data with a remote receiver via wireless device 25.

[0054] like Figure 2 As shown, the wireless device 25 includes one or more processors 250 and one or more memories 251. The one or more processors 250 may include, for example, a central processing unit (CPU), a digital signal processor (DSP), a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), etc. The one or more memories 251 may include any type of computer-readable volatile and non-volatile memory (hard disk, solid-state drive, optical disk, electronic storage, etc.). The one or more memories 251 may store a computer program product 252 in the form of a set of program code instructions to be executed by the one or more processors 250 to implement all or part of the steps of a method for exchanging data executed on the UE side according to any embodiment of the embodiments disclosed herein.

[0055] like Figure 2As shown, the wireless device 25 also includes a main radio MR unit 253 and a low-power wake-up signal receiver LP-WUR 254.

[0056] As discussed above, MR unit 253 corresponds to the main wireless communication unit of wireless device 25, which is used to exchange data with BS 30 of RAN using radio signals. MR unit 253 can implement one or more wireless communication protocols and can be, for example, a 3G, 4G, 5G, NR, WiFi, WiMax transceiver, etc. In a preferred embodiment, MR unit 253 corresponds to a 5G NR wireless communication unit.

[0057] The LP-WUR 254 corresponds to the secondary wireless communication unit of the wireless device 25, which is used to monitor a wake-up signal transmitted by the BS 30 of the RAN in a low-power manner. The wake-up signal can take any form that enables it to be detected in a low-power manner. Non-limiting examples of wake-up signals and the LP-WUR 254 are provided in technical report TR 38.869. It should be noted that in some examples, the wake-up signal can even be, for example, a specific 5G NR signal using a low-order modulation and coding scheme (MCS). In this case, the LP-WUR 254 may include components of the 5G NR wireless communication unit that are strictly required to detect such a specific 5G NR signal.

[0058] As discussed above, the primary purpose of the LP-WUR 254 is to monitor and detect wake-up signals (DL) transmitted by the RAN of a wireless communication system. Therefore, the LP-WUR 254 can be unidirectional only, i.e., having only receive (DL) capability and no transmit (UL) capability. However, in some examples, the LP-WUR 254 may also have transmit capability, allowing it to transmit (UL) data to the RAN as well.

[0059] The wireless device 25 is adapted to operate in at least two operating modes, including a normal operating mode and a low-power operating mode:

[0060] - In normal operating mode, MR unit 253 is active.

[0061] - In low-power operation mode, MR unit 253 is in a low-power state, and LP-WUR 254 is configured to trigger a transition to normal operation mode in response to the detection of a wake-up signal transmitted by RAN.

[0062] As discussed above, the active state corresponds to any state in which MR unit 253 can exchange data with the RAN without being triggered by LP-WUR.

[0063] A low-power state corresponds to a state in which MR unit 253 cannot exchange data with the RAN without being triggered by LP-WUR 254. For example, a low-power state corresponds to MR unit 253 always being in sleep mode. However, thanks to LP-WUR 254, MR unit 253 does not need to be periodically woken up in a low-power state, so MR unit 253 can be in a very deep sleep state and can even be turned off, since LP-WUR 254 can be used to turn on MR unit 253. Furthermore, it should be noted that different low-power states with correspondingly different average power consumption can be considered for MR unit 253. For example, an extremely low-power state with the lowest average power consumption can be considered, as well as one or more medium-low-power states with average power consumption greater than that of the extremely low-power state. For example, an extremely low-power state can correspond to MR unit 253 being turned off, and a medium-low-power state can correspond to MR unit 253 being in sleep mode without being turned off.

[0064] It should be noted that in some examples, the LP-WUR 254 can also be configured to trigger the MR unit 253 when other conditions are verified. For example, the LP-WUR 254 can be configured to trigger the MR unit 253 if a predetermined timer has expired without a detected wake-up signal. Such a timer can be used to ensure that the wireless device 25 can return to an active state when, for example, the wireless device 25 has moved out of the coverage area of ​​the wake-up signal. Of course, the duration of the timer should be long enough to ensure that the MR unit 253 remains in a low-power state for an extended period.

[0065] Figure 3 An example of a BS 30 is schematically shown that is suitable for implementing any of the methods discussed in this disclosure that are performed by the RAN.

[0066] like Figure 3 As shown, BS 30 includes one or more processors 300 and one or more memories 301. The one or more processors 300 may include, for example, a CPU, DSP, FPGA, ASIC, etc. The one or more memories 301 may include any type of computer-readable volatile and non-volatile memory (hard disk, solid-state drive, optical disk, electronic storage, etc.). The one or more memories 301 may store a computer program product 302 in the form of a set of program code instructions to be executed by the one or more processors 300 to implement all or part of the steps of a method for exchanging data executed on the RAN side according to any embodiment of the embodiments disclosed herein.

[0067] like Figure 3As shown, BS 30 also includes a wireless communication unit 303 configured to exchange data with UE 20 using radio signals, and more specifically with the MR unit 253 of the wireless device 25 included in these UEs 20. The wireless communication unit 303 may be, for example, a 3G, 4G, 5G, NR, WiFi, WiMax, or other transceivers. In a preferred embodiment, the wireless communication unit 303 of BS 30 corresponds to a 5G NR transceiver.

[0068] like Figure 3 As shown, BS 30 also includes a wake-up signal transmitter (WUT) 304, which is configured to send a wake-up signal to a UE having a wireless device 25 including an LP-WUR 254. Figure 3 In the example shown, WUT 304 is represented as separate from wireless communication unit 303. However, WUT 304 may also be included in wireless communication unit 303, for example, if wireless communication unit 303 is a 5G NR transceiver and if the wake-up signal is a specific 5G NR signal.

[0069] As discussed above regarding LP-WUR 254, if WUT 304 is separate from wireless communication unit 30, then the primary purpose of the WUT is to transmit (DL) wake-up signals. Therefore, WUT 304 can be unidirectional, i.e., having only transmit (DL) capability and no receive (UL) capability. However, in some examples, WUT 304 may also have receive capability, allowing it to receive (UL) data from UE 20's LP-WUR 254.

[0070] like Figure 3 As shown, BS 30 may also include a network communication unit 305 configured to exchange data with other base stations of the RAN and / or with the CN. The network communication unit 305 may support one or more suitable communication protocols, which may be wired (including optical) and / or wireless.

[0071] As discussed above, this disclosure aims to further reduce energy consumption when performing discontinuous reception DRX. It should be noted that DRX also covers the extended DRX (eDRX) defined by 3GPP. In DRX, the radio device 25 operates according to a DRX cycle, which includes:

[0072] - During DRX inactivity periods, wireless device 25 does not perform PDCCH monitoring, and

[0073] - During DRX activity periods, during which the radio device 25 can receive control data from the RAN via the PDCCH.

[0074] To reduce the need to keep MR unit 253 active during DRX activity periods, it is proposed to divide the DRX activity periods into multiple sub-periods, which include:

[0075] - One or more inactive sub-periods during which the RAN is unable to send control data to radio device 25 via PDCCH, and

[0076] - One or more active sub-periods during which the RAN can send control data to the radio device 25 via the PDCCH.

[0077] Since control data cannot be received via PDCCH during inactive sub-periods of the DRX active period, the MR unit 253 of the radio device 25 can be placed in a low-power state during each inactive sub-period of the DRX active period, so that the MR unit 253 no longer needs to be active for the entire duration of the DRX active period. Furthermore, and as will be discussed below, if the DRX active period includes an active sub-period following an inactive sub-period, the RAN can use the inactive sub-period to indicate whether it intends to transmit control data via PDCCH during the subsequent active sub-period. For example, such an indication can be transmitted as a wake-up signal to be detected by the LP-WUR 254 of the radio device 25. Therefore, if a wake-up signal is detected during an inactive sub-period of the DRX active period, the MR unit 253 can transition to an active state during the subsequent active sub-period of that DRX active period. Conversely, if no wake-up signal is detected during an inactive sub-period, the MR unit 253 can remain in a low-power state during the subsequent active sub-period. Furthermore, in some cases, if the LP-WUR 254 does not detect a wake-up signal during an inactive sub-period of the DRX active period, the LP-WUR 254 may also transition to a low-power state (e.g., off) for the duration of subsequent active sub-periods of the DRX active period to further reduce energy consumption during the DRX active period. In some examples, the LP-WUR 254 may also be placed in a low-power state (e.g., off) for all active sub-periods of the DRX active period.

[0078] As discussed above, a DRX active period may include one or more active sub-periods and one or more inactive sub-periods, which are arranged such that a DRX active period consists of alternations of active and inactive sub-periods. In other words, an active sub-period cannot immediately precede or follow another active sub-period, and an inactive sub-period cannot immediately precede or follow another inactive sub-period. Preferably, an active sub-period follows an inactive sub-period so that the wireless device 25 can be instructed whether its MR unit 253 needs to be put into an active state during the subsequent active sub-period.

[0079] Figure 4 These are illustrative examples of different DRX activity time-of-day configurations.

[0080] exist Figure 4 In the example shown in part a), the DRX active period consists of a single inactive sub-period followed by a single active sub-period.

[0081] exist Figure 4 In the example shown in part b), the DRX active period comprises three sub-periods. More specifically, the DRX active period begins with a first active sub-period, followed by an inactive sub-period, and then a second active sub-period. In this case, when a wake-up signal is detected in the preceding DRX inactive period, MR unit 253 transitions to an active state during the duration of the first active sub-period to perform PDCCH monitoring. During the inactive sub-period, PDCCH monitoring is not performed, and MR unit 253 may be placed in a low-power state. LP-WUR 254 performs wake-up signal monitoring during the inactive sub-period. If a wake-up signal is detected, MR unit 253 transitions to an active state during the duration of the second active sub-period to perform PDCCH monitoring. If no wake-up signal is detected, MR unit 253 may remain in a low-power state during the duration of the second active sub-period. LP-WUR 254 does not need to perform wake-up signal monitoring during the second active sub-period, making it possible to place in a low-power state in some examples.

[0082] exist Figure 4 In the example shown in part c), the DRX active period comprises four sub-periods. More specifically, the DRX active period begins with a first inactive sub-period, followed by a first active sub-period, followed by a second inactive sub-period, and then a second active sub-period.

[0083] exist Figure 4In the example shown in part d), the DRX active period comprises five sub-periods. More specifically, the DRX active period begins with a first active sub-period, followed by a first inactive sub-period, then a second active sub-period, then a second inactive sub-period, and finally a third active sub-period.

[0084] In some examples, the same duration can be considered for all inactive sub-periods and for all active sub-periods. However, it is also possible to consider inactive sub-periods with durations different from active sub-periods. Furthermore, inactive sub-periods can all have the same duration, or the duration can vary between different inactive sub-periods. Similarly, active sub-periods can all have the same duration, or the durations of active sub-periods can differ from one another.

[0085] Consider with Figure 4 The examples provided are compared to other DRX activity period configurations, such as those including additional active sub-periods and / or additional inactive sub-periods. The selection of a particular DRX activity period configuration corresponds to a specific, but not limiting, embodiment of this disclosure.

[0086] In some examples, the DRX activity period configuration may be predefined. In other examples, the DRX activity period configuration may be set by radio device 25 or by the RAN. In the latter case, the DRX activity period configuration to be used by radio device 25 is received, for example, by radio device 25 in system information broadcast by RAN's BS 30 and / or in a Radio Resource Control (RRC) reconfiguration message sent by RAN's BS 30. Of course, other control messages may be used by the RAN to send the DRX activity period configuration to radio device 25. In some cases, the DRX activity period configuration may be sent together with the DRX cycle configuration, which defines the DRX activity periods and DRX inactivity periods within a DRX cycle.

[0087] Figure 5 This schematically illustrates how wireless device 25 can be assumed in a non-limiting manner. Figure 4 The non-limiting example shown in part d) is the DRX activity period configuration to reduce its energy consumption.

[0088] In such Figure 5 In the example shown, the LP-WUR 254 performs wake-up signal monitoring during the DRX inactivity period of the DRX cycle, while the MR unit 253 is in a low-power state, such as the extremely low-power state discussed above.

[0089] exist Figure 5In part a), LP-WUR 254 does not detect a wake-up signal, causing PDCCH monitoring to be omitted during subsequent DRX activity periods. Therefore, MR unit 253 can remain in a low-power state throughout the entire DRX activity period, thereby reducing energy consumption compared to performing PDCCH monitoring at each DRX activity period. Furthermore, in some examples, and as... Figure 5 As shown in part a) in a non-limiting manner, the LP-WUR 254 can also be placed in a low-power state (e.g., off) throughout the entire DRX activity period.

[0090] exist Figure 5 In part b), LP-WUR 254 detects a wake-up signal at time T0 during the DRX inactive period. Therefore, radio device 25 assumes it may receive control data via PDCCH during the next DRX active period. Since the DRX active period begins with a first active sub-period, LP-WUR 254 transitions MR unit 253 to an active state during the duration of the first active sub-period, during which radio device 25 can receive control data via PDCCH. Since control data is not received via PDCCH during the first inactive sub-period, MR unit 253 can be placed in a low-power state during the duration of the first inactive sub-period. However, LP-WUR 254 performs wake-up signal monitoring during the first inactive sub-period. LP-WUR 254 detects a wake-up signal at time T1 during the first inactive sub-period, meaning the RAN can transmit control data via PDCCH during the subsequent active sub-period (i.e., the second active sub-period). Therefore, the LP-WUR 254 transitions the MR unit 253 to an active state during the duration of the second active sub-period, during which the wireless device 25 can receive control data via the PDCCH. Since no control data is received via the PDCCH during the second inactive sub-period, the MR unit 253 can be placed in a low-power state during the duration of the second inactive sub-period. However, the LP-WUR 254 performs wake-up signal monitoring during the second inactive sub-period. Figure 5 In the example shown in part b), no wake-up signal is detected during the second inactive sub-period, meaning the RAN does not intend to send control data via PDCCH during the subsequent sub-period (i.e., the third active sub-period). Therefore, MR unit 253 can remain in a low-power state during the third active sub-period. Furthermore, LP-WUR 254 does not need to perform wake-up signal monitoring during the third active sub-period. Therefore, LP-WUR 254 can be placed in a low-power state during the third active sub-period. For example, LP-WUR 254 can be turned off during the third active sub-period. In some examples, and as... Figure 5 As shown in part b) in a non-limiting manner, the LP-WUR 254 can also be placed in a low-power state (e.g., off) during all active sub-periods of the DRX active period.

[0091] It should be noted that the same low-power state of MR unit 253 can be used during both DRX inactivity and DRX activity periods. However, in some cases, different low-power states of MR unit 253 can be used during DRX inactivity and DRX activity periods respectively. For example, the low-power state used during DRX inactivity periods may correspond to the extremely low-power state of MR unit 253 discussed above, while the low-power state used during DRX activity periods may correspond to the moderately low-power state of MR unit 253.

[0092] Figure 6 The diagram illustrates the steps of an exemplary embodiment of a method 60 for exchanging data implemented by BS 30. Figure 7 The diagram illustrates the corresponding steps of an exemplary embodiment of a method 70 for exchanging data implemented by the wireless device 25 of the UE 20. It should be noted that... Figure 6 and Figure 7 Only a single inactive sub-period and a single active sub-period are shown. However, if a DRX active period includes more than one inactive sub-period and / or more than one active sub-period, the corresponding steps can be repeated.

[0093] As discussed above, the DRX active period includes one or more inactive sub-periods and one or more active sub-periods, and BS 30 is configured to send control data to the radio device 25 of UE 20 via PDCCH only during the active sub-periods. In other words, during the inactive sub-periods of the DRX active period, control data may not be sent to the radio device 25 via PDCCH.

[0094] exist Figure 6 In the non-limiting example shown, the method 60 for exchanging data includes step S60: during an inactive sub-period of a DRX active period, evaluating whether control data should be transmitted to the wireless device 25 via PDCCH in a subsequent active sub-period. If control data is to be transmitted via PDCCH in a subsequent active sub-period... Figure 6 If the marker S60a is used, then the method 60 for exchanging data includes: step S61 of sending a wake-up signal to the wireless device 25 during the current inactive sub-period, and step S62 of sending control data to the wireless device 25 via PDCCH during the subsequent active sub-period. Conversely ( Figure 6The marker S60b indicates that no wake-up signal is sent during the current inactive sub-period (and no control data is sent to the wireless device 25 via PDCCH during the subsequent active sub-period).

[0095] In some examples, and such as Figure 6 As shown, the method 60 for exchanging data includes step S63: during a DRX inactivity period, evaluating whether to transmit control data to the wireless device 25 via PDCCH during a subsequent DRX activity period. If control data is to be transmitted via PDCCH during a subsequent DRX activity period... Figure 6 If the marker S63a is specified, then the method 60 for exchanging data includes step S64: sending a wake-up signal to the wireless device 25 during the current DRX inactivity period. Conversely ( Figure 6 The marker S63b indicates that no wake-up signal is sent during the current DRX inactive period (and no control data is sent to the wireless device 25 via PDCCH during the subsequent DRX active period).

[0096] In some examples, and such as Figure 6 As shown in the non-limiting example, the method 60 for exchanging data includes step S65 of sending a DRX activity period configuration to the radio device 25. As discussed above, the DRX activity period configuration can be sent, for example, in system information broadcast by the BS 30 and / or in a Radio Resource Control (RRC) reconfiguration message sent to the radio device 25 (if the radio device 25 is in the RRC_CONNECTED state).

[0097] As discussed above, Figure 7 The diagram illustrates corresponding steps of an exemplary embodiment of a method 70 for exchanging data, which can be implemented in BS 30. Figure 6 The method 60 for exchanging data shown is implemented by the wireless device 25.

[0098] like Figure 7 As shown, the method 70 for exchanging data includes: during a DRX active period, step S70 of wake-up signal monitoring performed by LP-WUR 254 during an inactive sub-period (while MR unit 253 is in a low-power state). If no wake-up signal is detected during the current inactive sub-period ( Figure 7 If the marker S70b is used, then PDCCH monitoring is not performed during the subsequent active sub-period, and MR unit 253 can be maintained in a low-power state for the duration of the subsequent active sub-period (and, in some examples, LP-WUR 254 does not perform wake-up signal monitoring during the subsequent active sub-period and can be placed in a low-power state). Conversely ( Figure 7The method 70 for exchanging data (marked S70a) includes: step S71 of triggering the transition of MR unit 253 to an active state, and step S72 of performing PDCCH monitoring during a subsequent active sub-period.

[0099] In some examples, and such as Figure 7 As shown, the method 70 for exchanging data includes: during the DRX inactivity period, the LP-WUR 254 performs a wake-up signal monitoring step S73 (while the MR unit 253 is in a low-power state).

[0100] If no wake-up signal is detected during the current DRX inactivity period ( Figure 7 If the flag S73b is set in the diagram, then PDCCH monitoring is not performed during the subsequent DRX activity period, and MR unit 253 can be maintained in a low-power state for the duration of the subsequent DRX activity period (and, in some examples, LP-WUR 254 does not perform wake-up signal monitoring during the subsequent DRX activity period and can be placed in a low-power state). Therefore, steps S70, S71, and S72 discussed above are not performed.

[0101] in turn( Figure 7 The method 70 for exchanging data (marked S73a) performs steps S70, S71 and S72 as discussed above.

[0102] In some examples, and such as Figure 7 As shown, the method 70 for exchanging data includes step S74 of receiving a DRX activity period configuration from the RAN to be used during the DRX activity period. This DRX activity period configuration is received, for example, in system information broadcast by the RAN and / or in a Radio Resource Control (RRC) reconfiguration message sent by the RAN.

[0103] It should be emphasized that this disclosure is not limited to the exemplary embodiments described above. Variations of the exemplary embodiments described above are also within the scope of this disclosure.

Claims

1. A method (70) for exchanging data in a wireless communication system, the method being implemented by a wireless device (25) of the wireless communication system, wherein the wireless device comprises: The main radio MR unit (253) is configured to exchange data with the radio access network (RAN) of the wireless communication system. And a low-power wake-up receiver LP-WUR (254), the LP-WUR being configured to monitor a wake-up signal transmitted by the RAN and trigger a transition of the MR unit to an active state in response to the detection of a wake-up signal, wherein the radio device (25) is configured to receive discontinuous DRX cycles, wherein the DRX cycle includes a DRX active period and a DRX inactive period, during which the radio device (25) is capable of receiving control data from the RAN via a physical downlink control channel PDCCH, and during the DRX inactive period, the radio device (25) does not perform PDCCH monitoring, wherein the DRX active period includes an inactive sub-period and a subsequent active sub-period, and wherein in response to the LP-WUR (254) detecting a wake-up signal during the DRX inactive period, the method includes during the subsequent DRX active period: - (S70) During the inactive sub-period, wake-up signal monitoring is performed by the LP-WUR (254) while the MR unit is in a low-power state. - In response to the detection of a wake-up signal during the inactive sub-period: (S71) trigger the transition of the MR unit to the active state, and (S72) perform PDCCH monitoring during the active sub-period.

2. The method (70) of claim 1, wherein in response to no wake-up signal being detected during the inactive sub-period, the MR unit maintains the low-power state during the active sub-period.

3. The method (70) of claim 2, wherein in response to no wake-up signal being detected during the inactive sub-period, the LP-WUR does not perform wake-up signal monitoring during the active period.

4. The method (70) according to any one of the preceding claims, comprising: (S74) Receive DRX activity period configuration, the DRX activity period configuration defining the inactive sub-period and the active sub-period within the DRX activity period.

5. The method (70) according to claim 4, wherein the DRX activity period configuration is received in system information broadcast by the RAN, and / or in a Radio Resource Control (RRC) reconfiguration message sent by the RAN.

6. The method (70) according to any one of the preceding claims, wherein if no wake-up signal is detected during a DRX inactivity period, the wireless device (25) does not perform PDCCH monitoring during a subsequent DRX activity period.

7. The method (70) according to any one of the preceding claims, wherein the DRX active period includes a plurality of active sub-periods, and / or, the DRX active period includes a plurality of inactive sub-periods.

8. The method (70) according to any one of the preceding claims, wherein the DRX activity period begins with an activity sub-period.

9. The method (70) according to any one of the preceding claims, wherein during the DRX inactive period, the MR unit is maintained in a low-power state, which is 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 memory (251) and at least one processor (250), said at least one processor being configured to perform the method (70) according to any one of the preceding claims.

11. A user equipment (UE) (20) comprising the wireless means according to claim 10.

12. A method (60) for exchanging data in a wireless communication system, the method being 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 trigger a transition of the MR unit to an active state in response to detecting the wake-up signal transmitted by the BS, wherein the BS is configured to receive discontinuous DRX cycles, wherein the DRX cycle includes a DRX active period and a DRX inactive period, wherein during the DRX active period the BS is capable of transmitting control data to the wireless device via a physical downlink control channel (PDCCH), and during the DRX inactive period the BS does not transmit control data to the wireless device via the PDCCH, wherein the DRX active period includes at least one inactive sub-period and at least one active sub-period, and wherein the BS is configured to transmit control data to the wireless device via the PDCCH only during at least one active sub-period.

13. The method (60) according to claim 12, comprising: In response to determining that control data should be transmitted in an active sub-period following an inactive sub-period of the DRX active period, (S60) a wake-up signal is transmitted to the wireless device in the inactive sub-period.

14. The method (60) according to any one of claims 12 to 13, comprising: In response to determining that control data should be transmitted during the DRX active period, (S63) a wake-up signal is transmitted to the wireless device during the DRX inactive period prior to the DRX active period.

15. The method (60) according to any one of claims 12 to 14, comprising: (S65) Send a DRX activity period configuration to the wireless device, wherein the DRX activity period configuration defines the at least one inactive sub-period and the at least one active sub-period within the DRX activity period.

16. The method (60) of claim 15, wherein the DRX activity period configuration is sent in system information broadcast by the RAN, and / or the DRX activity period configuration is sent in a Radio Resource Control (RRC) reconfiguration message sent to the radio device.

17. The method (60) according to any one of claims 12 to 16, wherein the DRX activity period begins with an activity sub-period.

18. A base station BS (30) comprising at least one memory (301) and at least one processor (300), said at least one processor being configured to perform the 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 that, when executed by at least one processor, configure the at least one processor to perform the method (70) according to any one of claims 1 to 9 or the method (60) according to any one of claims 12 to 17.

21. A computer-readable storage medium comprising instructions that, when executed by at least one processor, configure the at least one processor to perform the method (70) according to any one of claims 1 to 9 or the method (60) according to any one of claims 12 to 17.

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