Method and apparatus for selecting low power mode of operation using UE-specific threshold

Abstract

The invention relates to a method and a device for saving energy at a user equipment side of a wireless communication system.

Description

Technical Field

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

[0002] To reduce energy consumption, Extended Discontinuous Receiver (eDRX) has been introduced in 3GPP (3rd Generation Partnership Project) wireless communication systems. Essentially, in eDRX, the UE periodically enters sleep mode and remains dormant for a specified duration, during which time it does not monitor the Physical Downlink Control Channel (PDCCH). It is then woken up and remains awake for the specified duration to monitor the PDCCH for any possible downlink data. The energy saved depends on how long and how often the UE remains dormant. Naturally, the longer the UE remains dormant, the greater the energy savings. However, increasing the dormant duration introduces increased latency, making eDRX unsuitable for latency-critical use cases.

[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 eDRX cycle, which constitutes the main energy consumption during cycles without signaling or data traffic. Energy consumption could be significantly reduced if the UE could only be woken up when triggered (e.g., paging). As studied by 3GPP, this is achieved by providing the UE with both a main radio MR unit and a low-power wake-up receiver (LP-WUR).

[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 any state in which the MR unit exchanges data with the radio access network (RAN) of the wireless communication system without being triggered by the LP-WUR. Therefore, a woken-up MR unit is in an active state. Moreover, an MR unit that is dormant but periodically woken up without being triggered by the LP-WUR (e.g., eDRX) is also in an active state.

[0007] The low-power state corresponds to the state where the MR unit cannot exchange data with the RAN without being triggered by the LP-WUR. For example, the low-power state corresponds to the state where the MR unit is always asleep. However, since the MR unit does not need to be periodically woken up in the low-power state, the MR unit can sleep even more deeply than in the current UE and can even be turned off, because the LP-WUR can be used to turn on the MR unit.

[0008] "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.

[0009] 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 with low power, and therefore, the average power consumption of the LP-WUR should be lower than (and preferably significantly lower, for example, ten times or even a hundred times lower) the average power consumption of the MR unit when it is awake.

[0010] Therefore, power 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 be woken up by the LP-WUR at any time, thereby reducing latency compared to, for example, eDRX.

[0011] While the specific details of LP-WUR and wake-up signals remain to be defined, the fact that LP-WUR should be able to detect wake-up signals with low power consumption implies that, for a given base station (BS) of the RAN, the coverage achievable by a wake-up signal monitored by LP-WUR may be less than the coverage achievable by a PDCCH monitored by the MR unit (also known as the cell). Therefore, at cell boundaries, the LP-WUR of a UE may not always detect wake-up signals sent by the BS. Summary of the Invention

[0012] 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 enabling a UE to disable the reception of a wake-up signal when each UE may be unable to detect the wake-up signal.

[0013] To this end, this disclosure proposes using a minimum receive level threshold, whereby the expected receive level of the wake-up signal should be higher than the minimum receive level threshold to continue monitoring the wake-up signal. Conversely, if the expected receive level of the wake-up signal falls below the minimum receive level threshold, reception of the wake-up signal should be disabled. More specifically, it is recommended that the minimum receive level threshold be adjusted for each UE to take into account the specific wake-up signal detection capability of each UE's LP-WUR.

[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 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 detect a wake-up signal transmitted by the RAN, wherein the wireless device includes at least two operating modes, the at least two operating modes including a normal operating mode and a low-power operating mode, wherein:

[0015] - In normal operating mode, the MR unit is active.

[0016] - In low-power operation mode, the MR unit is in an extremely low-power state, and the LP-WUR is configured to trigger a transition to normal operation mode in response to the detection of a wake-up signal sent by the RAN.

[0017] The method includes:

[0018] - Indication of minimum receive level threshold received from RAN.

[0019] - The estimated received level represents the expected received level of the LP-WUR in response to the wake-up signal transmitted by the RAN.

[0020] - The operating mode of the wireless device is selected by comparing the estimated received level with the minimum received level threshold.

[0021] In some embodiments, the method according to the first aspect may also include one or more of the following optional features, either individually or in any technically possible combination.

[0022] In some embodiments of the method according to the first aspect, the indication of the minimum received level threshold is received by the wireless device in the Radio Resource Control (RRC) connected state, accompanied by an indication of the transition from the RRC connected state to the RRC inactive state.

[0023] In some embodiments of the method according to the first aspect, the indication of the minimum received level threshold is received in the RRC release message.

[0024] In some embodiments of the method according to the first aspect, a low-power operating mode is selected in response to an estimated received level greater than a minimum received level threshold.

[0025] In some embodiments of the method according to the first aspect, a normal operating mode is selected in response to an estimated received level being below a minimum received level threshold.

[0026] In some embodiments, the method according to the first aspect includes notifying the RAN that a wake-up signal cannot be received at the wireless device in response to an estimated received level being below a minimum received level threshold.

[0027] In some embodiments of the method according to the first aspect, notifying the RAN that a wake-up signal cannot be received at the wireless device is accomplished by using auxiliary information, such as by using the Small Data Transmission (SDT) procedure.

[0028] According to a second aspect, this disclosure relates to a wireless device including at least one memory and at least one processor, the at least one processor being configured to implement a method according to any one of the embodiments of the first aspect.

[0029] 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.

[0030] 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, the wireless device including 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 from a very low-power state to an active state, wherein the method includes:

[0031] - Determine the minimum receive level threshold for wireless devices.

[0032] - Sends an indication of the minimum receive level threshold to the wireless device.

[0033] In some embodiments, the method according to the fourth aspect may also include one or more of the following optional features, either individually or in any technically possible combination.

[0034] In some embodiments of the method according to the fourth aspect, a minimum received level threshold is determined based on information received from the wireless device.

[0035] In some embodiments of the method according to the fourth aspect, a minimum received level threshold is determined based on information representing the receiver sensitivity of the wireless device.

[0036] In some embodiments of the method according to the fourth aspect, an indication of a minimum received level threshold is included in the Radio Resource Control (RRC) release message.

[0037] In some embodiments, the method according to the fourth aspect includes disabling the transmission of a wake-up signal to the wireless device in response to receiving an indication from the wireless device that a wake-up signal cannot be received.

[0038] According to a fifth aspect, this disclosure relates to a base station (BS) including at least one memory and at least one processor, the at least one processor being configured to implement a method according to any one of the embodiments of the fourth aspect.

[0039] According to a sixth aspect, this disclosure relates to a wireless communication system comprising at least one base station according to any one of the embodiments of this disclosure and at least one user equipment according to any one of the embodiments of this disclosure.

[0040] According to a seventh aspect, this disclosure relates to a computer program product comprising instructions that, when executed by at least one processor, configure the at least one processor to implement a method for exchanging data according to any of the embodiments of this 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.

[0041] According to an eighth aspect, this disclosure relates to a (non-transient) computer-readable storage medium comprising instructions that, when executed by at least one processor, configure the at least one processor to implement a method for sending control messages according to any one of the embodiments of this disclosure. Attached Figure Description

[0042] 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:

[0043] - Figure 1 : A schematic representation of an example of a wireless communication system including a BS and a UE.

[0044] - Figure 2 : A schematic representation of an example of a wireless device,

[0045] - Figure 3 : A schematic representation of a BS example

[0046] - Figure 4 and Figure 5 The flowcharts show examples of methods for exchanging data implemented by the wireless devices of the BS and UE, respectively.

[0047] 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

[0048] 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.

[0049] Generally, unless a different meaning is clearly given and / or implied from the context of the use of the term, all terms used herein will be interpreted according to their common meaning in the relevant art. Unless otherwise expressly stated, all references to a / an / said element, device, component, element, step, etc., will be interpreted openly as referring to at least one instance of said element, device, component, element, step, etc. Furthermore, the order of steps of any method disclosed herein, particularly in the figures, is provided for illustrative purposes only and is not intended to limit the disclosure. The disclosure may be applied where the same steps are performed in a different order and / or where steps are performed in parallel or in combination, unless a step is explicitly described as occurring after or before another step and / or where it is implied that a step must occur after or before another step. Moreover, in a figure, steps enclosed by dashed lines should be considered optional for the embodiment represented in that figure. Where appropriate, any feature of any of the embodiments disclosed herein may be applied to any other embodiment. Similarly, any advantage of any embodiment described herein may be applied to any other embodiment, and vice versa. Other objects, features, and advantages of the appended embodiments will be apparent from the following description.

[0050] Figure 1 The illustration depicts an example of a wireless communication system, which may be, for example, a 5G NR wireless communication system. More specifically, Figure 1The RAN represents a wireless communication system that exchanges data with the UE via radio signals. For example, the RAN can send data to the UE (downlink DL), such as data received from the core network (CN, not shown in the figure). The RAN can also receive data from the UE (uplink UL), which can be forwarded to the CN.

[0051] exist Figure 1 In the example shown, the RAN includes one base station BS 30. Of course, the RAN can include more than one BS30 to increase the coverage of the wireless communication system. Depending on the implemented wireless communication standard, each of these BSs can be called an NB, eNodeB (or eNB), gNodeB (or gNB, in the case of 5G NR wireless communication systems), access point, etc.

[0052] exist Figure 1 The example shown illustrates two UEs, 20-1 and 20-2. UEs 20-1 and 20-2 are located within the coverage area 31 (also known as the cell) of BS 30. The coverage area 31 of BS 30 essentially corresponds to the area where UEs can decode PDCCHs transmitted by BS 30.

[0053] Figure 2 An example of a wireless device 25 suitable for implementing any of the methods discussed in this disclosure at the UE is illustrated schematically. Essentially, the wireless device 25 corresponds to a device that provides wireless connectivity to a RAN (Radio Radio Network) of a wireless communication system and can be used to exchange data with said RAN.

[0054] This 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, vehicle (manned or unmanned), GPS device, etc., or any other equipment that can run applications that require exchanging data with a remote receiver via wireless device 25.

[0055] like Figure 2As 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 (magnetic hard disk, solid-state disk, 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 a method for exchanging data at the UE side according to any of the embodiments disclosed herein.

[0056] like Figure 2 As shown, the wireless device 25 also includes a main radio MR unit 253 and a low-power wake-up signal receiver LP-WUR 254.

[0057] 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.

[0058] 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.

[0059] As discussed above, the primary purpose of the LP-WUR 254 is to monitor and detect wake-up signals (DL) sent 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 send (UL) data to the RAN.

[0060] 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:

[0061] - In normal operating mode, MR unit 253 is active.

[0062] - 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 sent by RAN.

[0063] 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. Therefore, a woken-up MR unit 253 is in an active state. Moreover, an MR unit 253 that is dormant but periodically woken up (e.g., eDRX) without being triggered by LP-WUR 254 is also in an active state.

[0064] The low-power state corresponds to the state where MR unit 253 cannot exchange data with the RAN without being triggered by LP-WUR 254. For example, the low-power state corresponds to the state where MR unit 253 is always in sleep mode. However, since MR unit 253 does not need to be periodically woken up in the low-power state, due to the presence of LP-WUR 254, MR unit 253 can be in deep sleep mode and can even be turned off, as LP-WUR 254 can be used to turn on MR unit 253.

[0065] 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. This timer can be used to ensure that the wireless device 25 can return to an active state, for example, when the wireless device 25 has moved out of the wake-up signal's coverage area. 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.

[0066] Figure 3 An example of a BS 30 is schematically shown that is suitable for implementing any of the methods discussed in this disclosure by the RAN.

[0067] like Figure 3As 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 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 301 may include any type of computer-readable volatile and non-volatile memory (magnetic 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 a method for exchanging data at the RAN side according to any of the embodiments disclosed herein.

[0068] like Figure 3 As 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.

[0069] 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.

[0070] As discussed above regarding LP-WUR 254, if WUT 304 is separate from wireless communication unit 30, then the primary purpose of WUT 304 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 can also have receive capability, allowing it to receive (UL) data from UE 20's LP-WUR 254.

[0071] like Figure 3As shown, BS 30 may further 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.

[0072] As discussed above, the coverage area 31 of BS 30 can be wider than the coverage area achievable by the wake-up signal transmitted by BS 30. Therefore, wireless device 25 should be able to assess whether it will exceed the coverage area of ​​the wake-up signal, and if it does, it should avoid switching to a low-power operating mode.

[0073] Figure 4 A diagram illustrating the steps of an exemplary embodiment of a method 40 for exchanging data, implemented by BS 30. Figure 5 The diagram illustrates the corresponding steps of an exemplary embodiment of a method 50 for exchanging data implemented by the wireless device 25 of the UE 20.

[0074] like Figure 4 As shown, the method 40 for exchanging data includes step S40, namely, determining a minimum reception level threshold for a given wireless device 25, and step S41, namely, sending an indication of the determined minimum reception level threshold to the given wireless device 25.

[0075] As described above, the minimum receive level threshold is specifically determined for the wireless device 25 under consideration, and is selected, for example, from a plurality of possible minimum receive level thresholds, or from a range of possible minimum receive thresholds.

[0076] As will be discussed below, wireless device 25 will use a minimum receive level threshold to determine whether the expected receive level of the wake-up signal allows it to be detected by LP-WUR 254. If the expected receive level of the wake-up signal allows it to be detected by LP-WUR 254, then wireless device 25 may switch to a low-power operating mode if energy saving is required. Conversely, if the expected receive level of the wake-up signal prevents it from being detected by LP-WUR 254, then wireless device 25 should avoid switching to a low-power operating mode and should therefore remain in normal operating mode.

[0077] Using a minimum receive level threshold specific to radio device 25, rather than using the same minimum receive level threshold for all radio devices 25 (and UE 20), is advantageous because the corresponding LP-WUR 254 of radio devices 25 within the PDCCH coverage 31 of BS 30 can have, for example, different receiver sensitivities. This means that a wake-up received at a given receive level may be detected by some LP-WUR 254s with good receiver sensitivity, but not by some LP-WUR 254s with poor receiver sensitivity. Therefore, adjusting the minimum receive level threshold for each radio device 25, compared to using the same minimum receive level threshold for all radio devices 25, allows for an increase in the number of radio devices 25 that can benefit from low-power operation modes.

[0078] To determine the minimum receive level threshold specific to wireless device 25, BS 30 can use information associated with that wireless device 25. In some examples, such information associated with a particular wireless device 25 can be retrieved from a database accessible to BS 30. In other examples, and as... Figure 4 The method 40 for exchanging data, shown in a non-limiting manner, includes step S42, namely receiving information from a wireless device 25 and determining a minimum reception level threshold for the wireless device 25 based at least on the information received from the wireless device 25.

[0079] For example, the information received (and / or retrieved from a database) may represent the receiver sensitivity of the LP-WUR 254 of wireless device 25, or may be used to estimate the receiver sensitivity of the LP-WUR 254 of wireless device 25. BS 30 may use such information representing the receiver sensitivity of the LP-WUR 254 of wireless device 25 to adjust the minimum receive level threshold for the expected receive level of the wake-up signal.

[0080] For example, information indicating the receiver sensitivity of the LP-WUR254 can be received from the wireless device 25 in a UE assistance message and / or a UE capability message.

[0081] According to another example, BS 30 can use information received from wireless device 25 to estimate the receiver sensitivity of LP-WUR 254. This information can be received from wireless device 25 as a measurement report, in which wireless device 25 reports the measurement results of a reference signal associated with the wake-up signal.

[0082] In some examples, the information indicating receiver sensitivity can correspond to the actual receiver sensitivity of the LP-WUR 254 (e.g., expressed in dBm).

[0083] In other examples, different types of LP-WURs may be predefined, each with a different predefined receiver sensitivity. In this case, the information representing the receiver sensitivity can correspond to an identifier of the type of LP-WUR 254 of the wireless device 25 under consideration, and the BS 30 can use the identifier to retrieve the corresponding predefined receiver sensitivity and determine a suitable minimum received level threshold.

[0084] In other examples, BS 30 may use information received from wireless device 25 during the calibration phase. For instance, such a calibration phase may include BS 30 repeatedly transmitting a calibration signal (which may be a wake-up signal or a reference signal) for detection by the LP-WUR 254 of wireless device 25. BS 30 may begin transmitting the calibration signal at low transmit power and may gradually increase the transmit power with each repetition. LP-WUR 254 attempts to detect the calibration signal and, once detected, measures its received level. This measured received level of the calibration signal is sent to BS 30, which can use this measured received level to select a minimum received level threshold for wireless device 25.

[0085] Of course, BS 30 may use other types of information to determine the minimum reception threshold specifically for the wireless device 25 under consideration, and the selection of specific types of information corresponds to specific and non-limiting embodiments of this disclosure.

[0086] During step S41, BS 30 indicates the minimum receive level threshold to the wireless device 25 by using any appropriate signaling message.

[0087] For example, a minimum receive level threshold can be sent in a Radio Resource Control (RRC) message. For instance, an indication of the minimum receive level threshold is sent when the wireless device 25 is in an RRC connected state. For example, the RRC message used to indicate when the wireless device 25 transitions to an RRC inactive state is, for example, an RRC release message.

[0088] The indication of the minimum receive level threshold can correspond to the actual value of the minimum receive level threshold selected by BS 30. In other examples, the indication can correspond to an identifier of the minimum receive level threshold. In this case, the mapping between different possible minimum receive level thresholds and their corresponding identifiers can be pre-configured at wireless device 25. For example, such mapping can be predefined (e.g., specified by a standard), or it can be sent to wireless device 25 by BS 30 (e.g., included in system information broadcast by BS 30, or included in a message dedicated to wireless device 25).

[0089] As discussed above, Figure 5The diagram illustrates corresponding steps of an exemplary embodiment of a method 50 for exchanging data, which can be implemented in BS 30. Figure 4 The method 40 for exchanging data shown is implemented by the wireless device 25 of UE 20.

[0090] like Figure 5 As shown, the method 50 for exchanging data includes step S50, namely, receiving from BS 30 an indication of a minimum receive level threshold specifically determined for the wireless device 25. As discussed above, this indication can be received via any suitable message. For example, when the wireless device 25 is in an RRC connection state, the indication can be received in an RRC message, such as via an RRC release message.

[0091] As discussed above, in some examples, BS 30 can determine the minimum receive level threshold based on information transmitted by wireless device 25. Figure 5 In a non-limiting example, method 50 for exchanging data includes step S53, which involves sending such information to BS30.

[0092] like Figure 5 As shown in the non-limiting example, the method 50 for exchanging data includes step S51, which is to estimate the received level representing the expected received level of the LP-WUR 254 to the wake-up signal sent by the BS 30.

[0093] Essentially, the estimated receive level corresponds to any parameter that can be used to predict whether the wireless device 25 will be likely to detect the wake-up signal sent by the BS 30 to the wireless device 25. In fact, any measurement, including a measurement of the path loss between the BS 30 and the wireless device 25, can be considered as representing the expected receive level of the LP-WUR 254 to the wake-up signal sent by the BS 30, since the path loss depends on the distance between the BS 30 and the LP-WUR 254. Therefore, the estimated receive level can be determined, for example, by measuring any radio signal sent by the BS 30. For example, the estimated receive level can be determined by measuring a reference signal sent by the wireless communication unit 303 of the BS 30 (measured by the MR unit 253) or a reference signal sent by the WUT 304 of the BS 30 (measured by the MR unit 253 or by the LP-WUR 254). In other examples, the estimated receive level can also be determined based on a measurement of the wake-up signal sent by the BS 30. For example, the estimated receive level can be determined based on the following:

[0094] - The received level measured by the LP-WUR 254 of wireless device 25 for a wake-up signal sent from BS 30 to another wireless device, and / or

[0095] - The received level measured by the LP-WUR 254 of the wireless device 25 for a wake-up signal received during a previous period when the wireless device 25 was in a low-power operating mode.

[0096] For example, the estimated received level determined based on measurements of the reference signal transmitted by BS 30 can correspond to the reference signal received power RSRP and / or the reference signal received quality RSRQ of the reference signal as defined in the 3GPP specifications.

[0097] like Figure 5 As shown in the non-limiting example, the method 50 for exchanging data includes step S52, which selects the operating mode of the wireless device 25 by comparing an estimated received level (determined during step S51) with a minimum received level threshold (received in step S50).

[0098] For example, if wireless device 25 determines that the estimated received level is greater than the minimum received level threshold received from BS 30 ( Figure 5 If energy saving is required, the wireless device 25 considers that it can switch to a low-power operation mode. (Refer to S52a)

[0099] Conversely, if the wireless device 25 determines that the estimated received level is lower than the minimum received level threshold received from BS 30 ( Figure 5 If, as per reference S52b), the wireless device 25 determines that it cannot receive the wake-up signal, it should not transition to a low-power operating mode. Alternatively, and as... Figure 5 As shown in the non-limiting example, in this case, the wireless device 25 can notify the BS 30 that a wake-up signal cannot be received at the wireless device 25 by sending a corresponding message to the BS 30 during step S54. The BS 30 can be notified of the inability to receive a wake-up signal at the wireless device 25 using any suitable signaling message. For example, the wireless device 25 can use an auxiliary signal and / or a small data transmission SDT procedure to notify the BS 30 that a wake-up signal cannot be received.

[0100] like Figure 4 As shown in the non-limiting example, in this case, the method 40 for exchanging data includes step S43, namely receiving an indication from the wireless device 25 that it cannot receive a wake-up signal. In response to receiving such an indication from the wireless device 25, BS 30 may, for example, disable sending a wake-up signal to that particular wireless device 25.

[0101] Therefore, this disclosure proposes to increase the number of UEs 20 that can be placed in low-power operation mode by setting a UE-specific minimum received level threshold to authorize the use of low-power operation mode. Figure 1In the example shown, UE 20-2 has better receiver sensitivity than UE 20-1. Therefore, the RAN configures a lower minimum receive level threshold for UE 20-2 than the minimum receive level threshold for UE 20-1. Therefore, UE 20-2 can use the low-power operation mode of its radio device 25 in a wider coverage area 32-2 than UE 20-1 can use it in.

[0102] If the same minimum receive level threshold is used for all UEs 20, this same minimum receive level threshold will essentially correspond to the minimum receive level threshold required to prevent UE 20-1 from using a low-power operating mode (in which it cannot receive a wake-up signal), thus forcing all UEs 20 to use a low-power operating mode only within coverage area 32-1. In turn, this disclosure enables UE 20-2 to use its radio device 25 in a lower-power operating mode over a wider coverage area 32-2, thereby providing increased energy savings for UE 20-2.

Claims

1. A method (50) 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 detect a wake-up signal transmitted by the RAN, wherein the wireless device includes at least two operating modes, the at least two operating modes including a normal operating mode and a low-power operating mode, wherein: - In the normal operating mode, the MR unit is in an active state. - In the low-power operation mode, the MR unit is in an extremely low-power state, and the LP-WUR is configured to trigger a transition to the normal operation mode in response to detecting a wake-up signal sent by the RAN. The method includes: - (S50) Receive an indication of the minimum receive level threshold from the RAN. - (S51) Estimate the expected reception level of the LP-WUR for the wake-up signal sent by the RAN. - (S52) Select the operating mode of the wireless device by comparing the estimated received level with the minimum received level threshold.

2. The method (50) according to claim 1, wherein the indication of the minimum received level threshold is received by the wireless device in a Radio Resource Control (RRC) connected state, and is accompanied by an indication of transition from the RRC connected state to an RRC inactive state.

3. The method (50) according to claim 2, wherein the indication of the minimum received level threshold is received in an RRC release message.

4. The method (50) according to any one of the preceding claims, wherein the low-power operation mode is selected in response to the estimated received level being greater than the minimum received level threshold.

5. The method (50) according to any one of the preceding claims, wherein the normal operating mode is selected in response to the estimated received level being lower than the minimum received level threshold.

6. The method (50) of claim 5, the method comprising notifying the RAN that a wake-up signal cannot be received at the wireless device in response to the estimated receive level being lower than the minimum receive level threshold.

7. The method (50) of claim 6, wherein the notification that the RAN cannot receive a wake-up signal at the wireless device is accomplished by using auxiliary information, such as by using a small data transmission SDT process.

8. A wireless device (25) comprising at least one memory (251) and at least one processor (250), the at least one processor being configured to implement the method (50) according to any one of the preceding claims.

9. A user equipment (UE) (20), the UE comprising the wireless device (25) according to claim 8.

10. A method (40) 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), the wireless device including 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, in response to detecting the wake-up signal transmitted by the BS, trigger a transition of the MR unit from a very low-power state to an active state, wherein the method includes: - (S40) Determine the minimum received level threshold for the wireless device. - (S41) Send an indication of the minimum receive level threshold to the wireless device.

11. The method (40) of claim 10, wherein the minimum receive level threshold is determined based on information received from the wireless device.

12. The method (40) according to any one of claims 10 to 11, wherein the minimum reception level threshold is determined based on information representing the receiver sensitivity of the wireless device.

13. The method (40) according to any one of claims 10 to 12, wherein the indication of the minimum received level threshold is included in the Radio Resource Control (RRC) release message.

14. The method (40) according to any one of claims 10 to 13, the method comprising, in response to receiving an indication from the wireless device that a wake-up signal cannot be received, disabling the transmission of a wake-up signal to the wireless device.

15. A base station (BS) (30), the BS comprising at least one memory (301) and at least one processor (300), the at least one processor being configured to implement the method (40) according to any one of claims 10 to 14.

16. A wireless communication system comprising at least one base station (30) according to claim 15 and at least one user equipment (20) according to claim 9.

17. A computer program product comprising instructions that, when executed by at least one processor, configure the at least one processor to perform the method according to any one of claims 1 to 7 or the method according to any one of claims 10 to 14.

18. 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 according to any one of claims 1 to 7 or the method according to any one of claims 10 to 14.

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