Method and apparatus for implementing energy saving on a UE that is performing a scheduling requirement procedure

Abstract

The present disclosure relates to methods and devices for enabling a user equipment (UE - user equipment) (20) having a low power wake-up signal receiver (LP-WUR - low power wake-up signal receiver) (254) to reduce its energy consumption during a scheduling request procedure.

Description

Technical area

[0001] The present disclosure relates to wireless communication systems, and more particularly, to methods and apparatus for conserving power on a user equipment (UE) side of the wireless communication system. background

[0002] To reduce energy consumption, discontinuous reception (DRX) was introduced in 3GPP (Third Generation Partnership Project) wireless communication systems. Essentially, with DRX, the UE periodically enters a sleep state for a sleep period, during which a physical downlink control channel (PDCCH) is not monitored, before waking up for a wake period to monitor the PDCCH for possible downlink control data. The amount of energy that can be saved depends on how long and how frequently the UE remains in the sleep state. Obviously, the longer the UE remains in the sleep state, the greater the amount of energy saved.

[0003] To improve energy savings without sacrificing latency in 5G or New Radio (NR) wireless communication systems, 3GPP is ready to define a new architecture for UEs (see, for example, technical report TR 38.869).

[0004] Essentially, current UEs must periodically wake up once per DRX cycle, which dominates energy consumption during periods without signaling or data traffic. If UEs were able to wake up only when triggered, e.g., by a page, energy consumption could be drastically reduced. As explored by 3GPP, this is achieved by deploying the UE with both a main radio (MR) unit and a low-power wake-up receiver (LT-WUR).

[0005] Essentially, the MR unit corresponds to the 5G NR wireless communication unit, and the LT-WUR corresponds to a wireless communication unit used to monitor a wake-up signal during low-power conditions. Once the wake-up signal is detected, the LP-WUR can trigger the MR unit, which can transition from a low-power state to an active state.

[0006] The active state corresponds to a state in which the MR unit can exchange data with a 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] By “power-saving” state, the authors mean that the average power consumption of the MR unit in the power-saving state is lower (and preferably significantly lower, e.g., ten or even one hundred times lower) than the average power consumption of the MR unit in the active state.

[0008] By "wake-up receiver from the "low power" state, the authors mean that the LP-WUR is used to receive a wake-up signal while the MR unit is in a low power state. Obviously, monitoring the wake-up signal should be performed at low power consumption, and the average power consumption of the LP-WUR should therefore be lower (and preferably significantly lower, e.g., ten or even one hundred times lower) than the average power consumption of the MR unit when it is in the active state.

[0009] Thus, power consumption is reduced by placing the MR unit in a low-power state (e.g., turned off). The MR unit does not need to wake up periodically, and only needs to wake up 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, further enabling low latency.

[0010] However, there is a need to further reduce the energy consumption of specific processes, such as the scheduling request (SR) process.

[0011] The SR procedure enables a UE to request uplink (UL) resources to transmit data to the RAN. For that purpose, a UE may be allocated SR resources, which may be used by the UE to transmit a UL request (to request additional UL resources for an upcoming transmission). Such SR resources may, for example, be allocated by the RAN to a UE in a radio resource control (RRC) connected (RRC_CONNECTED) state or in an RRC inactive (RRC_INACTIVE) state. Essentially, the UL request is a physical layer message that can be sent by the UE in the SR resources to notify the RAN that it has UL data to be transmitted.In response to receiving such an SR-related UL request from the UE, the RAN may transmit a DL response to that UE over the PDCCH containing a UL grant indicating the UL resources granted to the UE for the upcoming transmission.

[0012] Once the UE transmits the SR-related UL request, it starts a timer (sr-ProhibitTimer) that defines a DL response period during which the DL response (containing the UL grant) can be received from the RAN. The UE does not know when the DL response will be received, so it must continuously monitor the PDCCH until the DL response is received. Thus, in some cases, the UE must monitor for almost the entire duration of the DL response period (i.e., the entire duration of the sr-ProhibitTimer). For example, if different logical channels (LCHs) with different respective priorities are defined, the UL request can use SR resources of an SR configuration mapped to a low-priority LCH.In such a case, the DL response is not prioritized by the RAN and could only be transmitted towards the end of the DL response period, while the UE starts monitoring the PDCCH directly at the beginning of the DL response period. Brief description

[0013] The present disclosure aims to improve the situation. In particular, the present disclosure aims to address 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 during which the MR unit must remain in the active state within a DL response period used to transmit a DL response to an uplink request transmitted during a random access procedure.

[0014] 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, wherein the wireless device comprises a main 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, in response to detecting a wake-up signal, to trigger a transition of the MR unit to an active state, wherein the wireless device is configured to perform a scheduling request (SR) procedure,by transmitting an uplink (UL) request to the RAN over SR resources and by receiving a downlink (DL) response indicating granted UL resources over a physical downlink control channel (PDCCH) within a DL response period, wherein the DL response period comprises an inactive sub-period followed by an active sub-period, and the method during the DL response period comprises: - monitoring for a wake-up signal by the LP-WUR during the inactive part-period, with the MR unit in a power-saving state, - in response to detecting a wake-up signal during the inactive sub-period: triggering a transition of the MR unit to the active state and performing PDCCH monitoring during the active sub-period.

[0015] In some embodiments, the method according to the first aspect may further comprise one or more of the following optional features, contemplated either alone or in any technically possible combination.

[0016] In some embodiments of the method according to the first aspect, in response to not detecting a wake-up signal during the inactive sub-period, the MR unit is maintained in the power saving state during the active sub-period.

[0017] In some embodiments of the method according to the first aspect, in response to not detecting a wake-up signal during the inactive sub-period, the LP-WUR does not monitor for a wake-up signal during the active sub-period.

[0018] In some embodiments, the method according to the first aspect comprises receiving a configuration for a DL response period that defines the inactive sub-period and the active sub-period within the DL response period.

[0019] In some embodiments of the method according to the first aspect, the configuration for a DL response period is received in system information sent by the RAN and / or the configuration for a DL response period is received in a radio resource control (RRC) message transmitted by the RAN.

[0020] In some embodiments of the method according to the first aspect, the DL response period comprises a plurality of active sub-periods and / or the DL response period comprises a plurality of inactive sub-periods.

[0021] In some embodiments, the method according to the first aspect comprises receiving, from the RAN, an indication of whether the DL response period begins with an active sub-period or with an inactive sub-period.

[0022] In some embodiments of the method according to the first aspect, the indication is received in system information transmitted by the RAN and / or the indication is received in a radio resource control (RRC) message transmitted by the RAN.

[0023] According to a second aspect, the present disclosure relates to a wireless device comprising at least one memory and at least one processor configured to perform a method according to any of the embodiments of the first aspect.

[0024] According to a third aspect, the present disclosure relates to a user equipment (UE) comprising a wireless device according to any of the embodiments of the present disclosure.

[0025] According to a fourth aspect, the present disclosure relates to a method for exchanging data in a wireless communication system, wherein the method is 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 comprises 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 a wake-up signal transmitted by the BS, to trigger a transition of the MR unit to an active state, wherein the BS is configured to perform a scheduling request (SR) procedure,by monitoring SR resources for receiving an uplink (UL) request from the wireless device and, in response to detecting a UL request from the wireless device, transmitting a downlink (DL) response indicating granted UL resources over a physical downlink control channel (PDCCH) within a DL response period, wherein the DL response period includes at least one inactive sub-period and at least one active sub-period, and wherein the BS is configured to transmit the DL response over the PDCCH to the wireless device only in the at least one active sub-period of the DL response period.

[0026] In some embodiments, the method according to the fourth aspect may further comprise one or more of the following optional features, contemplated either alone or in any technically possible combination.

[0027] In some embodiments, the method according to the fourth aspect comprises, in response to determining that the DL response is to be transmitted in an active sub-period following an inactive sub-period of the DL response period: transmitting a wake-up signal to the wireless device in that inactive sub-period.

[0028] In some embodiments, the method according to the fourth aspect comprises transmitting a configuration for a DL response period to the wireless device, wherein the configuration for a DL response period defines the at least one inactive sub-period and the at least one active sub-period within the DL response period.

[0029] In some embodiments of the method according to the fourth aspect, the configuration for a DL response period is transmitted in system information sent by the RAN and / or the configuration for a DL response period is transmitted in a radio resource control (RRC) message transmitted to the wireless device.

[0030] In some embodiments, the method according to the fourth aspect comprises transmitting to the wireless device an indication of whether the DL response period begins with an active sub-period or with an inactive sub-period.

[0031] In some embodiments of the method according to the fourth aspect, the indication is transmitted in system information sent by the RAN and / or the indication is transmitted in a radio resource control (RRC) message transmitted by the RAN.

[0032] According to a fifth aspect, the present disclosure relates to a base station (BS) comprising at least one memory and at least one processor configured to perform a method according to any of the embodiments of the fourth aspect.

[0033] According to a sixth aspect, the present disclosure relates to a wireless communication system comprising at least one base station according to any of the embodiments of the present disclosure and at least one user equipment according to any of the embodiments of the present disclosure.

[0034] According to a seventh aspect, the present disclosure relates to a computer program product comprising 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 of the embodiments 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 form between source code and object code, such as in a partially compiled form, or in any other desired form.

[0035] According to an eighth aspect, the present disclosure relates to a (non-transitory) computer-readable storage medium comprising instructions that, when executed by at least one processor, configure the at least one processor to perform a method for transmitting control messages according to any of the embodiments of the present disclosure. Short description of the drawings

[0036] The invention will be better understood upon reading the following description, given as an example and in no way limiting, with reference to the figures, which show: - Fig. 1: a schematic representation of an example of a wireless communication system comprising a BS and UEs, - Fig. 2: a schematic representation of an example of a wireless device, - Fig. 3: a schematic representation of an example of a BS, - Fig. 4: schematic representations of examples of different configurations of a DL response period, - Fig. 5: a schematic diagram illustrating the operation of a wireless device during a DL response period, - Fig. 6 and Fig. 7: Flowcharts illustrating examples of methods for exchanging data implemented by a BS and a wireless device of a UE, respectively.

[0037] In these figures, reference numerals that are identical from one figure to another indicate identical or similar elements. For clarity, the elements shown are not to scale unless expressly stated otherwise. Detailed description

[0038] The detailed description below with reference to the figures is intended to be a description of various configurations and is not intended to be the only configurations in which the presently described concepts may 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 may be practiced without these specific details. For example, while this disclosure may use 3GPP terminology, e.g., from 5G NR, to explain embodiments herein, this should not be seen as limiting the scope of the present disclosure.

[0039] In general, all terms used herein should be interpreted according to their usual meaning in the relevant technical field, unless another meaning is clearly indicated and / or clear from the context in which it is used. All references to an element, facility, component, means, step, etc. should be openly construed as referring to at least one instance of the element, facility, component, means, step, etc., unless expressly stated otherwise.Likewise, the order of steps of any methods disclosed herein, particularly in the figures, is provided for illustrative purposes only and does not imply any limitation on the present disclosure, which may be applied with the same steps performed in a different order and / or with all or part of the steps performed in parallel or together, unless a step is expressly described as following or preceding a step and / or where it is implicit that a step must follow or precede another step. Likewise, steps depicted in a figure that are surrounded by a dashed line are to be considered optional for the embodiment depicted in that figure.Any feature of any of the embodiments disclosed herein may be applied to any other embodiment whenever appropriate. Likewise, any advantage of any of the embodiments may be applicable to any other embodiment, and vice versa. Other objects, features, and advantages of the included embodiments will become apparent from the following description.

[0040] Fig. Figure 1 schematically illustrates an example of a wireless communication system, which may be, for example, a 5G NR wireless communication system. In particular, Fig. Figure 1 depicts a RAN of the wireless communication system used to exchange data with UEs 20 via radio signals. The RAN can, for example, send data to the UEs 20 (DL - downlink), such as data received from a core network (CN - core network, not shown in the figures). The RAN can also receive data from the UEs 20 (UL - uplink), and this data can be forwarded to the CN.

[0041] In the Fig. In the example illustrated in Figure 1, the RAN includes a base station (BS) 30. Of course, the RAN may include more than one BS 30 to expand the coverage area of ​​the wireless communication system. Each of these BSs may be referred to as an NB, eNodeB (or eNB), gNodeB (or gNB in ​​the case of a 5G NR wireless communication system), an access point, or the like, depending on the wireless communication standard(s) implemented.

[0042] In the Fig. In the example illustrated in Figure 1, two UEs 20 are shown. The UEs 20 are located in a coverage area 31 of the BS 30. The coverage area 31 of the BS 30 corresponds, for example, to the range in which UEs can decode a PDCCH transmitted by the BS 30.

[0043] Fig. Figure 2 schematically illustrates an example of a wireless device 25 suitable for implementing any method discussed in the present disclosure and performed on a UE 20. Essentially, the wireless device 25 corresponds to a device that provides wireless connectivity to the RAN of the wireless communication system and that can be used to exchange data with the RAN.

[0044] Such a wireless device 25 may be incorporated in a UE 20 as shown by Fig. 2. The UE 20 may be, for example, a mobile phone, a wireless modem, a wireless communication device, a handheld device, a laptop computer, or the like. The UE 20 may also be an Internet of Things (IoT) device, such as a wireless camera, a smart sensor, smart glasses, a (manned or unmanned) vehicle, a global positioning system device, etc., or any other device capable of executing applications that require exchanging data with remote receivers via the wireless device 25.

[0045] As through Fig. 2, 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 (magnetic hard drive, solid-state memory, optical disk, electronic memory, etc.).The one or more memories 251 may store a computer program product 252 in the form of a set of program-encoded 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 performed on the side of a UE according to any of the embodiments disclosed herein.

[0046] As through Fig. 2, the wireless device 25 also includes a main radio (MR) unit 253 and a low power wake-up signal receiver (LP-WUR) 254.

[0047] As discussed above, the MR unit 253 corresponds to a main wireless communication unit of the wireless device 25, which is used to exchange data with BSs 30 of the RAN using radio signals. The MR unit 253 can implement one or more wireless communication protocols and can be, for example, a 3G, 4G, 5G, NR, WiFi, WiMax, etc., transceiver or the like. In preferred embodiments, the MR unit 253 corresponds to a 5G NR wireless communication unit.

[0048] The LP-WUR 254 corresponds to a secondary wireless communication unit of the wireless device 25, which is used to monitor a wake-up signal transmitted by BSs 30 of the RAN at low power consumption. The wake-up signal may take any form that allows it to be detected at low power consumption. Non-limiting examples of the wake-up signal and the LP-WUR 254 are provided in technical report TR 38.869. It is noted that in some examples, the wake-up signal may even be a specific 5G NR signal, for example, using a low-level modulation and coding scheme (MCS). In this case, the LP-WUR 254 may consist of the components of a 5G NR wireless communication unit that are explicitly expected to be capable of detecting such a specific 5G NR signal.

[0049] As discussed above, the primary purpose of the LP-WUR 254 is to monitor and detect a wake-up (DL) signal transmitted through the RAN of the wireless communication system. Thus, the LP-WUR 254 may be unidirectional, meaning it has only receive (DL) capabilities and no transmit (UL) capabilities. However, in some examples, the LP-WUR 254 may also have transmit capabilities, allowing it to also transmit data to the RAN (UL).

[0050] The wireless device 25 is designed to operate in at least two operating modes, including a normal operating mode and a power saving operating mode: - in normal operating mode, the MR unit 253 is in an active state, - in the power saving mode of operation, the MR unit 253 is in a power saving state and the LP-WUR 254 is configured to trigger a transition to the normal operating mode in response to detecting a wake-up signal transmitted by the RAN.

[0051] As discussed above, the active state corresponds to any state in which the MR unit 253 can exchange data with the RAN without being triggered by the LP-WUR.

[0052] The power-save state corresponds to a state in which the MR unit 253 cannot exchange data with the RAN without being triggered by the LP-WUR 254. For example, the power-save state corresponds to the state in which the MR unit 253 is always in sleep mode. However, since the MR unit 253 does not need to wake up periodically in the power-save state, the MR unit 253 can be in extremely deep sleep mode thanks to the LP-WUR 254 and can even be turned off, since the LP-WUR 254 can be used to turn on the MR unit 253. It is also noted that it is possible to consider different power-save states for the MR unit 253, each with a different average power consumption.For example, it is possible to consider a very low power state having the lowest average power consumption, as well as one or more intermediate power-saving states having an average power consumption greater than the average power consumption of the very low power state. For example, the very low power state may correspond to the one in which the MR unit 253 is turned off, and an intermediate power-saving state may correspond to the one in which the MR unit 253 is in the sleep state without being turned off.

[0053] It should be noted that in some examples, the LP-WUR 254 may also be configured to trigger the MR unit 253 when other conditions are verified. For example, the LP-WUR 254 may be configured to trigger the MR unit 253 when a predetermined timer has expired without detecting a wake-up signal. Such a timer may be used to ensure that the wireless device 25 can return to the active state if, for example, the wireless device 25 has moved out of the coverage area of ​​the wake-up signal. Of course, the duration of this timer should be sufficiently long to ensure that the MR unit 253 can remain in a power-saving state for long periods of time.

[0054] Fig. 3 schematically illustrates an example of a BS 30 suitable for implementing any method discussed in the present disclosure as well as performed by the RAN.

[0055] As through Fig. 3, the OS 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, a DSP, an FPGA, an ASIC, etc. The one or more memories 301 may include any type of computer-readable volatile and non-volatile memory (magnetic hard disk, solid-state memory, optical disk, electronic memory, etc.). The one or more memories 301 may store a computer program product 302 in the form of a set of program-encoded 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 performed at the RAN side according to any of the embodiments disclosed herein.

[0056] As through Fig. 3, the BS 30 also includes a wireless communication unit 303 configured to exchange data with UEs 20 using radio signals, and in particular with MR units 253 of wireless devices 25 included in these UEs 20. The wireless communication unit 303 may, for example, be a 3G, 4G, 5G, NR, WiFi, WiMax, etc. transceiver or the like. In preferred embodiments, the wireless communication unit 303 of the BS 30 corresponds to a 5G NR transceiver.

[0057] As through Fig. 3, the BS 30 also includes a wake-up signal transmitter (WUT) 304 configured to transmit wake-up signals to UEs having a wireless device 25 including an LP-WUR 254. In the embodiment illustrated by Fig. In the example illustrated in Figure 3, the WUT 304 is shown as separate from the wireless communication unit 303. However, the WUT 304 may also be included in the wireless communication unit 303, e.g., if the wireless communication unit 303 is a 5G NR transceiver and if the wake-up signal is a specific 5G NR signal.

[0058] As discussed above for the LP-WUR 254, the primary purpose of the WUT 304, when separate from the wireless communication unit 30, is to transmit a (DL) wake-up signal. Thus, the WUT 304 may be unidirectional, meaning it may only have transmit (DL) capabilities and no receive (UL) capabilities. However, in some examples, the WUT 304 may also have receive capabilities, allowing it to also receive (UL) data from an LP-WUR 254 of a UE 20.

[0059] As through Fig. As illustrated in Figure 3, the 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 that are wired (including fiber optic) and / or wireless.

[0060] As discussed above, the present disclosure aims to further reduce the power consumption of the wireless device 25 when performing an SR procedure.

[0061] As discussed above, during an SR procedure, the wireless device 25 typically uses SR resources to transmit a UL (uplink) request to the RAN (requesting UL resources for an upcoming transmission), and the RAN may transmit a DL (downlink) response to the wireless device 25 over the PDCCH during a DL response period (e.g., defined by the sr-ProhibitTimer). The DL response includes an indication of the granted UL resources, if any. Such SR resources may, for example, be allocated by the BS to a wireless device 25 in the RRC_CONNECTED state or in an RRC_INACTIVE state.

[0062] For example, the SR-related UL request is transmitted by the MR unit 253 in the active state. However, in other examples, the UL request may be transmitted by the LP-WUR 254 (assuming the LP-WUR 254 has transmission capabilities), in which case the MR unit 253 may be in a power-saving state when the LP-WUR 254 transmits the UL request.

[0063] In order to reduce the need to keep the MR unit 253 in the active state during a DL response period of an SR procedure, it is proposed to divide the DL response period (e.g., defined by the sr-ProhibitTimer) into a plurality of sub-periods containing the following: - one or more inactive sub-periods during which the RAN cannot transmit a DL response to the wireless device 25, and - one or more active sub-periods during which the RAN may transmit a DL response to the wireless device 25.

[0064] Since no DL response can be received during an inactive sub-period of the DL response period, the MR unit 253 of the wireless device 25 may be placed in a power-saving state during each inactive sub-period of the DL response period, such that the MR unit 253 no longer needs to remain in the active state for the entire duration of the DL response period. Also, and as discussed below, if the DL response period includes an active sub-period following an inactive sub-period, the RAN may use this inactive sub-period to indicate whether this RAN intends to transmit the DL response during the following active sub-period. For example, such an indication may be sent as a wake-up signal to be detected by the LP-WUR 254 of the wireless device 25.Thus, if a wake-up signal is detected during an inactive sub-period of the DL response period, the MR unit 253 may transition to the active state for the following active sub-period of the DL response period. Conversely, if no wake-up signal is detected during an inactive sub-period, the MR unit 253 may remain in a power-saving state during the following active sub-period. Likewise, in some cases, if no wake-up signal is detected by the LP-WUR 254 during an inactive sub-period of the DL response period, the LP-WUR 254 may also transition to a power-saving state (e.g., be turned off) for the duration of the following active sub-period of the DL response period to further reduce power consumption during the DL response period. In some examples, the LP-WUR 254 may also be placed in a power-saving state during all active sub-periods of the DL response period (e.g.,switched off).

[0065] As discussed above, the DL response period may include one or more active sub-periods and one or more inactive sub-periods arranged such that the DL response period is composed of an alternation of one or more active sub-periods and one or more inactive sub-periods. In other words, an active sub-period cannot be immediately followed or preceded by another active sub-period, and an inactive sub-period cannot be immediately followed or preceded by another inactive sub-period. Preferably, an inactive sub-period is always followed by an active sub-period to be able to indicate to the wireless device 25 whether its MR unit 253 needs to be placed in the active state for that following active sub-period.

[0066] Fig. Figure 4 schematically illustrates various examples of configurations of a DL response period.

[0067] In the case of part a) of Fig. In the example illustrated in Figure 4, the DL response period includes a single inactive sub-period followed by a single active sub-period.

[0068] In the case of part b) of Fig. In the example illustrated in Figure 4, the DL response period comprises three subperiods. Specifically, the DL response period begins with a first active subperiod, followed by an inactive subperiod, followed by a second active subperiod.

[0069] In the case of part c) of Fig. In the example illustrated in Figure 4, the DL response period comprises four sub-periods. Specifically, the DL response period begins with a first inactive sub-period, followed by a first active sub-period, followed by a second inactive sub-period, followed by a second active sub-period.

[0070] In the case of part d) of Fig. In the example illustrated in Figure 4, the DL response period comprises five subperiods. Specifically, the DL response period begins with a first active subperiod, followed by a first inactive subperiod, followed by a second active subperiod, followed by a second inactive subperiod, followed by a third active subperiod.

[0071] In some examples, it is possible to consider an identical duration for all inactive sub-periods and all active sub-periods. However, it is also possible to consider a duration for the inactive sub-periods that is different from the duration of the active sub-periods. Likewise, the inactive sub-periods may all have the same duration, or the duration may vary from one inactive sub-period to another. Similarly, the active sub-periods may all have the same duration, or the duration may vary from one active sub-period to another.

[0072] Other configurations of a DL response period may be considered, which, compared to those in Fig. 4, for example, additional active sub-periods and / or additional inactive sub-periods. The selection of a specific configuration for a DL response period corresponds to a specific, but non-limiting, embodiment of the present disclosure.

[0073] In some examples, the configuration for a DL response period may be predefined. In other examples, the configuration for a DL response period may be determined by the wireless device 25 or by the RAN. In the latter case, the configuration for a DL response period to be used by the wireless device 25 is received, for example, by the wireless device 25 in system information sent by a BS 30 of the RAN and / or in a radio resource control (RRC) message transmitted by a BS 30 of the RAN (for example, an RRC reconfiguration message). Of course, other control messages may be used by the RAN to transmit a configuration for a DL response period to the wireless device 25.

[0074] In some cases, the RAN may also transmit to the wireless device 25 an indication of whether the DL response period begins with an active sub-period or an inactive sub-period, which is included in the DL response period configuration or separate from the DL response period configuration. If such an indication (whether the DL response period begins with an active sub-period or an inactive sub-period) is transmitted separately from the DL response period configuration, the structure of the DL response period may be dynamically adapted by modifying only the type of sub-period with which the DL response period begins, i.e., either an inactive sub-period or an active sub-period.Such an indication may, for example, be included in system information sent by the RAN and / or in a radio resource control (RRC) message transmitted by the RAN. Such an indication may, for example, consist of a single bit. For example, a value of '0' may be used to indicate that the DL response period begins with an inactive sub-period, while a value of '1' may be used to indicate that the DL response period begins with an active sub-period.

[0075] It is noted that a BS 30 may specify the same DL response period configuration for all UEs 20 in its coverage area 31, or it may specify different DL response period configurations for all or part of the UEs 20 in its coverage area 31. For example, the BS 31 may specify UE-specific DL response period configurations. In some cases, the BS 30 may also modify one or more DL response period configurations based on its current or predicted load / traffic.

[0076] Fig. Figure 5 schematically illustrates a non-limiting example of how the wireless device 25 can reduce its power consumption by adopting, in a non-limiting way, the configuration for a DL response period described in part d) of Fig. 4 is shown.

[0077] As through Fig. As illustrated in Figure 5, the wireless device 25 transmits a UL request at a time T0. This UL request is transmitted, for example, by the MR unit 253 in the active state.

[0078] Accordingly, the wireless device 25 considers that it may receive a DL response (containing a UL grant) during a subsequent DL response period.

[0079] If the DL response period is defined by a timer (e.g., the sr-ProhibitTimer), it can start immediately after the UL request is transmitted. In the non-limiting example of Fig. 5, however, the DL response period is slightly delayed relative to T0. In other examples, the DL response period can, of course, start directly at T0.

[0080] Since the DL response period begins with a first active sub-period, the MR unit 253 is in the active state for the duration of the first active sub-period, during which the wireless device 25 can receive a DL response over the PDCCH. However, in the non-limiting example represented by Fig. 5, no DL response is received during the first inactive sub-period.

[0081] Since no DL response is to be received during the first inactive sub-period, the MR unit 253 can be placed in a power-saving state for the duration of the first inactive sub-period. However, the LP-WUR 254 monitors for a wake-up signal during the first inactive sub-period. Fig. 5, no wake-up signal is detected during the first inactive sub-period, which means that the RAN does not intend to transmit a DL response during the following sub-period, i.e., the second active sub-period. Accordingly, the MR unit 253 does not need to perform PDCCH monitoring and may be kept in a power-saving state during the second active sub-period. Also, the LP-WUR 254 does not need to monitor for a wake-up signal during the second inactive sub-period. Accordingly, the LP-WUR 254 may be placed in a power-saving state during the second active sub-period. For example, the LP-WUR 254 may be turned off during the second active sub-period. In some examples, and as described in a non-limiting manner in Fig. 5, the LP-WUR 254 may also be placed in a power saving state (e.g., turned off) during all active sub-periods of the DL response period.

[0082] Since no DL response is to be received during the second inactive sub-period, the MR unit 253 can remain in a power-saving state for the duration of the second inactive sub-period. However, the LP-WUR 254 monitors for a wake-up signal during the second inactive sub-period. Fig. 5, the LP-WUR 254 detects a wake-up signal at time T1 within the second inactive sub-period, which means that the RAN can transmit the DL response during the following active sub-period, i.e., the third active sub-period. Accordingly, the LP-WUR 254 transitions the MR unit 253 to the active state for the duration of the third active sub-period, during which the wireless device 25 can receive a DL response to its UL request. In the Fig. 5, the MR unit 253 receives the DL response (containing a UL grant) at a time T2.

[0083] Fig. 6 illustrates a diagram showing steps of an exemplary embodiment of a method 60 for exchanging data implemented by a BS 30. Fig. Figure 7 illustrates a diagram showing corresponding steps of an exemplary embodiment of a method 70 for exchanging data implemented by a wireless device 25 of a UE 20. It is noted that the Fig. 6 and Fig. 7 may only show a single inactive sub-period and a single active sub-period, but the corresponding steps may also be repeated if the DL response period includes more than one inactive sub-period and / or more than one active sub-period.

[0084] As discussed above, the DL response period includes one or more inactive sub-periods and one or more active sub-periods, and the BS 30 is configured to transmit a DL response to a UL request to the wireless device 25 of a UE 20 only during one or more active sub-periods. In other words, no DL response may be transmitted to the wireless device 25 during inactive sub-periods of the DL response period.

[0085] In the Fig. 6, the method 60 for exchanging data during an inactive sub-period of the DL response period includes a step S60 of evaluating whether a DL response (containing a UL grant) should be transmitted to the wireless device 25 over the PDCCH in the following active sub-period. If in the following active sub-period (reference sign S60a in Fig. 6) a DL response is to be transmitted over the PDCCH, the method 60 for exchanging data comprises a step S61 of transmitting a wake-up signal to the wireless device 25 in the current inactive sub-period and a step S62 of transmitting, during the following active sub-period, the DL response over the PDCCH to the wireless device 25. In return (reference symbol S60b in Fig. 6) no wake-up signal is transmitted during the current inactive sub-period (and no DL response is transmitted to the wireless device 25 during the following active sub-period).

[0086] As discussed above, the DL response period is typically triggered by the wireless device 25 transmitting a UL request using SR resources. As indicated by Fig. 6, the method 60 for exchanging data includes a step S63 of monitoring the SR resources for a UL request. If a UL request is detected (reference symbol S63a in Fig. 6), a DL response period is triggered. In return (reference symbol S63b in Fig. 6) no DL response period is triggered.

[0087] In some examples, and as in the non-limiting example of Fig. 6, the method 60 for exchanging data includes a step S64 of transmitting a configuration for a DL response period to the wireless device 25. As discussed above, the configuration for a DL response period may be transmitted, for example, in system information sent by the BS 30 and / or in a radio resource control (RRC) message transmitted to the wireless device 25. As discussed above, an indication of whether the DL response period begins with an inactive period or with an active period may also be transmitted to the wireless device 25.

[0088] As discussed above, Fig. 7 is a diagram showing corresponding steps of an exemplary embodiment of a method 70 for exchanging data that may be implemented by a wireless device 25 when the BS 30 executes the method 60 for exchanging data implemented by Fig. 6 is implemented.

[0089] As through Fig. 7, the method 70 for exchanging data during a DL response period includes a step S70 of monitoring for a wake-up signal during an inactive sub-period by the LP-WUR 254 (while the MR unit 253 is in a power-saving state). If during the current inactive sub-period (reference symbol S70b in Fig. 7) no wake-up signal is detected, no PDCCH monitoring is performed during the following active sub-period, and the MR unit 253 may be maintained in a power-saving state for the duration of the following active sub-period (and in some examples, the LP-WUR 254 does not monitor for a wake-up signal during the following active sub-period and may be placed in a power-saving state). In turn (reference symbol S70a in Fig. 7), the method 70 for exchanging data comprises a step S71 of triggering a transition of the MR unit 253 to the active state and a step S72 of performing PDCCH monitoring during the following active sub-period to receive the DL response indicating the granted UL resources.

[0090] As discussed above, the DL response period is typically triggered by the wireless device 25 transmitting a UL request over SR resources. As indicated by Fig. 7, the method 70 for exchanging data includes a step S73 of evaluating whether a UL request should be transmitted to the RAN. If a UL request should be transmitted (reference symbol S73a in Fig. 7), the method 70 for exchanging data includes a step S74 of transmitting the UL request using the SR resources, which triggers a DL response period. In return (reference symbol S73b in Fig. 7) no DL response period is triggered.

[0091] In some examples, and as in the non-limiting example of Fig.7, the method 70 for exchanging data includes a step S75 of receiving a DL response period configuration from the RAN to be used during the one or more DL response periods. As discussed above, the DL response period configuration is received, for example, in system information sent by the RAN and / or in a radio resource control (RRC) message transmitted by the RAN. As discussed above, the wireless device 25 may also receive an indication from the RAN as to whether the DL response period begins with an inactive period or an active period.

[0092] It is emphasized that the present disclosure is not limited to the above exemplary embodiments. Variants of the above exemplary embodiments are also within the scope of the present disclosure. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] TR 38.869

[0003]

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, the wireless device comprising 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, in response to detecting a wake-up signal, to trigger a transition of the MR unit to an active state, the wireless device (25) being configured to perform a scheduling request (SR) procedure,by transmitting an uplink (UL) request to the RAN for SR resources and by receiving a downlink (DL) response indicating granted UL resources over a physical downlink control channel (PDCCH) within a DL response period, wherein the DL response period comprises an inactive sub-period followed by an active sub-period, and the method during the DL response period comprises: - (S70) monitoring for a wake-up signal by the LP-WUR (254) during the inactive sub-period, wherein the MR unit is in a power-saving state, - in response to detecting a wake-up signal during the inactive sub-period: (S71) triggering a transition of the MR unit to the active state and (S72) performing PDCCH monitoring during the active sub-period. [2] The method (70) of claim 1, wherein the MR unit is maintained in the power saving state during the active sub-period in response to not detecting a wake-up signal during the inactive sub-period. [3] The method (70) of claim 2, wherein the LP-WUR, in response to not detecting a wake-up signal during the inactive sub-period, does not monitor for a wake-up signal during the active sub-period. [4] The method (70) of any preceding claim, comprising (S75) receiving a configuration for a DL response period that defines the inactive sub-period and the active sub-period within the DL response period. [5] The method (70) of claim 4, wherein the configuration for a DL response period is received in system information sent by the RAN and / or the configuration for a DL response period is received in a radio resource control (RRC) message transmitted by the RAN. [6] Method (70) according to one of the preceding claims, wherein the DL response period comprises a plurality of active sub-periods and / or the DL response period comprises a plurality of inactive sub-periods. [7] A method (70) according to any one of the preceding claims, comprising receiving, from the RAN, an indication of whether the DL response period begins with an active sub-period or with an inactive sub-period. [8] The method (70) of claim 7, wherein the indication is received in system information transmitted by the RAN and / or the indication is received in a radio resource control (RRC) message transmitted by the RAN. [9] A wireless device (25) comprising at least one memory (251) and at least one processor (250) configured to perform a method (70) according to any one of the preceding claims. [10] A user equipment (UE) (20) comprising a wireless device according to claim 9. [11] 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, the BS being configured to exchange data with a wireless device (25), the wireless device comprising a main radio (MR) unit (253) and a low power wake-up receiver (LP-WUR) (254), the LP-WUR being configured to detect a wake-up signal transmitted by the BS and, in response to detecting a wake-up signal transmitted by the BS, to trigger a transition of the MR unit to an active state, the BS (30) being configured to perform a scheduling request (SR) procedure,by monitoring SR resources for receiving an uplink (UL) request from the wireless device and, in response to detecting a UL request from the wireless device, transmitting a downlink (DL) response indicating granted UL resources over a physical downlink control channel (PDCCH) within a DL response period, wherein the DL response period includes at least one inactive sub-period and at least one active sub-period, and wherein the BS is configured to transmit the DL response over the PDCCH to the wireless device only in the at least one active sub-period of the DL response period. [12] The method (60) of claim 11, comprising, in response to determining that the DL response is to be transmitted in an active sub-period following an inactive sub-period of the DL response period: (S61) transmitting a wake-up signal to the wireless device in that inactive sub-period. [13] The method (60) of any one of claims 11 to 12, comprising (S64) transmitting a configuration for a DL response period to the wireless device, wherein the configuration for a DL response period defines the at least one inactive sub-period and the at least one active sub-period within the DL response period. [14] The method (60) of claim 13, wherein the configuration for a DL response period is transmitted in system information sent by the RAN and / or the configuration for a DL response period is transmitted in a radio resource control (RRC) message transmitted by the wireless device. [15] The method (60) of any one of claims 11 to 14, comprising transmitting to the wireless device an indication of whether the DL response period begins with an active sub-period or with an inactive sub-period. [16] The method (60) of claim 15, wherein the indication is transmitted in system information sent by the RAN and / or the indication is transmitted in a radio resource control (RRC) message transmitted by the RAN. [17] Base station (BS - base station) (30), comprising at least one memory (301) and at least one processor (300) configured to carry out a method (60) according to one of claims 11 to 16. [18] A wireless communication system comprising at least one base station (30) according to claim 17 and at least one user device (20) according to claim 10. [19] A computer program product (252, 302) comprising instructions that, when executed by at least one processor, configure the at least one processor to perform a method (70) according to any one of claims 1 to 8 or a method (60) according to any one of claims 11 to 16. [20] A computer-readable storage medium comprising instructions that, when executed by at least one processor, configure the at least one processor to perform a method (70) according to any one of claims 1 to 8 or a method (60) according to any one of claims 11 to 16.

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