Method and apparatus for notifying RAN of wake-up signal monitoring status of UE using contention-based uplink resources

Abstract

The present disclosure relates to a method and apparatus for enabling a user equipment, UE, (20) to transmit information related to a low power wakeup signal receiver, LP-WUR, (254) of a wireless device (25) of the UE.

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 power 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 amount of power saved depends on how long the UE remains dormant and how often. Naturally, the longer the UE remains dormant, the greater the power 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 (and preferably significantly lower, for example, ten times or even a hundred times lower) than 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 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] However, new signaling methods are needed to enable the RAN to collect information from the UE with the LP-WUR in a manner that limits overhead and power consumption at the UE side, for example, to know whether the UE has activated wake-up signal reception through its LP-WUR. Summary of the Invention

[0012] This disclosure aims to improve this situation. Specifically, 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 that enables the RAN to know, at least in some cases, whether the UE has enabled wake-up signal reception via its LP-WUR in a manner that limits overhead and power consumption at the UE side.

[0013] 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 and a low-power wake-up receiver (LP-WUR), the MR unit being configured to exchange data with a radio access network (RAN) of the wireless communication system, the LP-WUR being configured to detect a wake-up signal transmitted by the RAN and, in response to detecting the wake-up signal transmitted by the RAN, trigger a transition of the MR unit from a very low-power state to an active state, wherein the method includes: transmitting information related to the LP-WUR to the RAN using a first contention-based uplink resource, wherein the first contention-based uplink resource is independent of a second contention-based uplink resource used for transmitting information unrelated to the LP-WUR.

[0014] In some embodiments, the method according to the first aspect may also include one or more of the following optional features, considered individually or in any technically possible combination.

[0015] In some embodiments of the method according to the first aspect, the second contention-based uplink resource includes a random access channel (RACH) resource, which is used by the MR unit to establish communication with the RAN.

[0016] In some embodiments of the method according to the first aspect, the second contention-based uplink resource includes a common configuration license (CG) uplink resource, which is used by the MR to transmit information unrelated to the LP-WUR, and the first contention-based uplink resource corresponds to a separate common CG uplink resource used by the radio device to transmit information related to the LP-WUR.

[0017] In some embodiments of the method according to the first aspect, information related to the LP-WUR is sent in the Media Access Control (MAC) control element (CE).

[0018] In some embodiments of the method according to the first aspect, information related to the LP-WUR is encoded in the Logical Channel Identifier (LCID) field of the MAC CE.

[0019] In some embodiments of the method according to the first aspect, the first contention-based uplink resource is divided into multiple subsets, and the method includes:

[0020] Select a subset from multiple subsets of the first contention-based uplink resources.

[0021] Send information related to LP-WUR by using a selected subset.

[0022] In some embodiments of the method according to the first aspect, the subset to be used is randomly selected from a plurality of subsets of first contention-based uplink resources.

[0023] In some embodiments of the method according to the first aspect, the subset to be used is selected based on a subset identifier received from the RAN.

[0024] In some embodiments of the method according to the first aspect, the information related to the LP-WUR transmitted by using a first contention-based uplink resource includes the wake-up signal monitoring status of the LP-WUR.

[0025] 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 perform a method according to any one of the embodiments of the first aspect.

[0026] According to a third aspect, this disclosure relates to a user equipment (UE) including a wireless means according to any one of the embodiments of this disclosure.

[0027] 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 plurality of wireless devices, at least some of which are low-power (LP) wireless devices, wherein each LP wireless device includes a master 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 low-power state to an active state, wherein the method includes:

[0028] A first contention-based uplink resource is allocated to the LP radio device, which is then used by the LP radio device to transmit information related to its LP-WUR.

[0029] A second contention-based uplink resource is allocated to the wireless device for transmitting information unrelated to the LP-WUR, wherein the second contention-based uplink resource is independent of the first contention-based uplink resource.

[0030] In some embodiments, the method according to the fourth aspect may also include one or more of the following optional features, considered individually or in any technically possible combination.

[0031] In some embodiments of the method according to the fourth aspect, the second contention-based uplink resource includes a random access channel (RACH) resource, which is used by a wireless device to establish communication with a BS.

[0032] In some embodiments of the method according to the fourth aspect, the second contention-based uplink resource includes a common configuration license (CG) uplink resource for radio devices to transmit information unrelated to the LP-WUR, and the first contention-based uplink resource corresponds to a separate common CG uplink resource for LP radio devices to transmit information related to their LP-WUR.

[0033] In some embodiments of the method according to the fourth aspect, the first contention-based uplink resources are divided into multiple subsets.

[0034] In some embodiments, the method according to the fourth aspect includes: sending to an LP radio device a mapping between a plurality of subsets of a first contention-based uplink resource and a plurality of corresponding subset identifiers, and sending to each LP radio device a subset identifier of the first contention-based uplink resource for use by the LP radio device.

[0035] In some embodiments, the method according to the fourth aspect includes: transmitting to an LP radio device a mapping between a plurality of subsets of first contention-based uplink resources and a plurality of corresponding numerical ranges for each LP radio device to select a subset of the first contention-based uplink resources.

[0036] In some embodiments of the method according to the fourth aspect, the information related to the LP-WUR transmitted using a first contention-based uplink resource includes the wake-up signal monitoring status of the LP-WUR.

[0037] 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 perform a method according to any one of the embodiments of the fourth aspect.

[0038] 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.

[0039] 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.

[0040] According to an eighth aspect, this 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 implement a method for sending control messages according to any one of the embodiments of this disclosure. Attached Figure Description

[0041] 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:

[0042] - Figure 1 This is a schematic diagram illustrating an example of a wireless communication system including a BS and a UE.

[0043] - Figure 2 This is a schematic diagram illustrating an example of a wireless device.

[0044] - Figure 3 This is a schematic diagram of a BS example.

[0045] - Figure 4 and Figure 5 These are flowcharts illustrating examples of methods for exchanging data implemented by the wireless devices of the BS and UE, respectively.

[0046] - Figure 6 and Figure 7 These are flowcharts illustrating other 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 of the embodiments 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 represents an example of a wireless communication system, which may be, for example, a 5G NR wireless communication system. More specifically, Figure 1 This refers to the RAN (Radio Access Network) of the wireless communication system, which is used to exchange data with UE 20 via radio signals. For example, the RAN can send data to UE 20 (downlink DL), such as data received from the core network (CN, not shown in the figure). The RAN can also receive data from UE 20 (uplink UL), which can be forwarded to the CN.

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

[0052] exist Figure 1 In the example shown, two UEs 20 are represented. UE 20 is located within the coverage area 31 of BS 30. The coverage area 31 of BS 30 essentially corresponds to the area where the UE can decode the PDCCH 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 20 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 device capable of running applications that require exchanging data with a remote receiver via wireless device 25.

[0055] like Figure 2 As shown, the wireless device 25 includes one or more processors 250 and one or more memories 251. The one or more processors 250 may include, for example, a central processing unit (CPU), a digital signal processor (DSP), a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), etc. The one or more memories 251 may include any type of computer-readable volatile and non-volatile memory (hard disk, solid-state drive, optical disk, electronic storage, etc.). The one or more memories 251 may store a computer program product 252 in the form of a set of program code instructions executable by the one or more processors 250 to implement all or part of the steps of 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, thanks to LP-WUR 254, MR unit 253 does not need to be periodically woken up in the low-power state, so MR unit 253 can be in a very deep sleep state and can even be turned off, because 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, for example, the wireless device 25 has moved out of the coverage area of ​​the wake-up signal, the wireless device 25 can return to an active state. 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 that are performed by the RAN.

[0067] like Figure 3 As shown, BS 30 includes one or more processors 300 and one or more memories 301. The one or more processors 300 may include, for example, a 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 (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 executable by the one or more processors 300 to implement all or part of the steps of a method for exchanging data at the RAN side according to any of the embodiments disclosed herein.

[0068] like Figure 3As shown, BS 30 also includes a wireless communication unit 303 configured to exchange data with UE 20 using radio signals, and more specifically with the MR unit 253 of the wireless device 25 included in these UEs 20. The wireless communication unit 303 may be, for example, a 3G, 4G, 5G, NR, WiFi, WiMax, or other transceivers. In a preferred embodiment, the wireless communication unit 303 of BS 30 corresponds to a 5G NR transceiver.

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

[0071] like Figure 3 As 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, this disclosure aims to enable BS 30 to collect information about the LP-WUR 254 of wireless device 25 within its coverage area, such as whether wireless device 25 within its coverage area has enabled its LP-WUR 254 and can detect wake-up signals sent by BS 30. For example, if wireless device 25 wishes to switch to a low-power operating mode, it needs to notify BS 30 that wireless device 25 has begun using its LP-WUR 254 to monitor downlink wake-up signals. In other words, wireless device 25 may need to send its LP-WUR 254 wake-up signal monitoring status to BS 30. For example, the wake-up signal monitoring status may indicate that the LP-WUR 254 is activated and ready to detect wake-up signals (e.g., if wireless device 25 switches to a low-power operating mode), or that the LP-WUR 254 is deactivated and cannot detect wake-up signals (e.g., if wireless device 25 switches to normal operating mode). Upon receiving such a wake-up signal monitoring status from the wireless device 25, the BS 30 may enable the transmission of wake-up signals to the wireless device 25 (if the wake-up signal monitoring status indicates that LP-WUR 254 is activated) or disable the transmission of wake-up signals to the wireless device 25 (if the wake-up signal monitoring status indicates that LP-WUR 254 is deactivated).

[0073] We now present an example of a signaling policy that can be implemented to enable a wireless device 25 equipped with an LP-WUR 254 to send information related to its LP-WUR 254 to the BS 30. This disclosure primarily relates to... Figure 2 The radio device 25 referred to is equipped with an LP-WUR 254 that can switch the MR unit 253 from a low-power state to an active state. Of course, the BS 30 may also have a UE 20 with a conventional radio device (i.e., a radio device without an LP-WUR) within its coverage area 31. In the following text, the radio device 25 equipped with the LP-WUR 254 may be referred to as the LP radio device 25 when it is necessary to distinguish it from a conventional radio device without an LP-WUR.

[0074] We now provide a non-limiting example of how (LP) wireless device 25 can provide BS 30 with information related to its LP-WUR 254.

[0075] Contention-based uplink resources

[0076] Figure 4 A diagram illustrating the steps of an exemplary embodiment of a method 40 for exchanging data, implemented by BS 30. Figure 5The diagram illustrates the corresponding steps of an exemplary embodiment of a method 50 for exchanging data implemented by the LP wireless device 25 of the UE 20.

[0077] like Figure 4 As shown, the method 40 for exchanging data includes:

[0078] Step S40: Allocate a first contention-based uplink resource for the LP radio device 25 to transmit information related to its LP-WUR 254 to the LP radio device 25.

[0079] Step S41: Allocate a second contention-based uplink resource (i.e., for the wireless device to transmit information unrelated to LP-WUR) to the wireless device, wherein the second contention-based uplink resource is independent of the first contention-based uplink resource.

[0080] "Contest-based uplink resources" refers to uplink resources shared by multiple wireless devices, on which each of these wireless devices can decide for itself to send messages, which may therefore conflict with messages from other wireless devices sharing these uplink resources.

[0081] The first contention-based uplink resource is allocated to the LP radio devices 25 and can be used by these LP radio devices 25 to transmit information related to their LP-WUR 254, such as wake signal monitoring status. In some examples, the first contention-based resource may be used solely for transmitting wake signal monitoring status. In other examples, the first contention-based uplink resource may also be used alternatively or in combination to transmit other types of information related to the LP-WUR 254 of the LP radio devices 25.

[0082] The second contention-based uplink resource is typically allocated to radio devices, specifically both the LP radio device 25 and the conventional radio device within the coverage area 31 of BS 30. This second contention-based uplink resource is used to transmit information unrelated to the LP-WUR and is independent of the first contention-based resource.

[0083] Therefore, the first contention-based uplink resource can be used solely by LP radio device 25, while the second contention-based uplink resource can be used by both LP radio device 25 (e.g., in normal operating mode) and conventional radio devices. Thus, the first contention-based uplink resource is shared by fewer radio devices than the second contention-based resource, which reduces the probability of collisions because only LP radio device 25 competes for the first contention-based uplink resource. Reducing the probability of collisions for information transmitted by LP radio devices 25 related to their LP-WUR 254 reduces the need for retransmissions, which in turn reduces the associated signaling overhead and associated power consumption of LP radio device 25.

[0084] In, for example, 5G NR wireless communication systems, examples of contention-based uplink resources include Random Access Channel (RACH) resources used by radio devices to establish communication with BS 30. Such RACH resources are allocated to radio devices regardless of their Radio Resource Control (RRC) status. In some examples, a second contention-based uplink resource corresponds to a RACH resource allocated by BS 30 to enable each radio device (LP or conventional) within its coverage area to initiate communication with BS 30. In this case, the first contention-based uplink resource is independent of the RACH resource shared by all radio devices and corresponds to a contention-based uplink resource that can be used solely by LP radio devices 25 to transmit information related to their LP-WUR 254. In some examples, the first contention-based uplink resource can be allocated to all LP radio devices 25 regardless of their RRC state (e.g., RRC connected (RRC_CONNECTED), RRC idle (RRC_IDLE), or RRC inactive (RRC_INACTIVE) state) and can be regarded as an LP RACH resource for use by LP radio devices 25.

[0085] In, for example, 5G NR wireless communication systems, other examples of contention-based uplink resources include publicly configured licensed (CG) uplink resources. For instance, such publicly configured CG uplink resources are allocated to radio devices in the RRC_CONNECTED state. "Public" means that these CG uplink resources can be shared by multiple radio devices. Furthermore, 5G NR wireless communication systems may also allocate dedicated CG uplink resources to specific radio devices in the RRC_CONNECTED state, which are used only by that specific radio device and are therefore not contention-based uplink resources. In some examples, a second contention-based uplink resource corresponds to a publicly configured CG uplink resource, and a first contention-based uplink resource corresponds to a separate publicly configured CG uplink resource, for example, that will be used only by LP radio devices 25 to transmit information related to their LP-WUR 254.

[0086] like Figure 4 As shown, the method 40 for exchanging data includes step S42: sending information describing a first contention-based uplink resource allocated to the LP wireless device 25. For example, the transmission of this information describing the allocated first contention-based uplink resource by the BS 30 can be a broadcast transmission (e.g., in the case of LP RACH resources), or the transmission can be a multicast transmission (e.g., in the case of public CG uplink resources). Furthermore, method 40 includes step S43: sending information describing a second contention-based uplink resource allocated to the wireless devices (LP wireless device 25 and conventional wireless devices). For example, the transmission of this information describing the allocated second contention-based uplink resource by the BS 30 can be a broadcast transmission (e.g., in the case of RACH resources), or the transmission can be a multicast transmission (e.g., in the case of public CG uplink resources).

[0087] like Figure 4 As shown, the method 40 for exchanging data then includes step S44: receiving information related to the LP-WUR 254 of the LP radio device 25 in a first contention-based uplink resource.

[0088] For example, each LP radio device 25 may transmit its LP-WUR 254 wake-up monitoring status in these first contention-based uplink resources, and the BS 30 may use the received wake-up monitoring status to control the transmission of wake-up signals to the LP radio device 25 from which it has received the wake-up monitoring status. In some examples, if the identity of the LP radio device 25 making the transmission is not implicit to the BS 30, the information associated with the LP radio device 25's LP-WUR 254 may also include the identifier of that LP radio device 25, so that the BS 30 knows which LP radio device 25 has, for example, activated or deactivated its LP-WUR 254.

[0089] In some examples, the first contention-based uplink resources are divided into multiple subsets. Such separate subsets can be used by different LP radio devices 25, such that the number of LP radio devices 25 competing for a particular subset is less than the total number of LP radio devices 25 in the coverage area 31 of the BS 30, which further reduces the probability of collisions and the need for retransmissions.

[0090] In some examples, the first subset of contention-based uplink resources available to a particular LP radio device 25 can be selected by the BS 30. In this case, the BS 30 can send a message to each particular LP radio device 25 within its coverage area 31, the message containing an identifier of the specific subset of the first contention-based uplink resources available to that particular LP radio device 25. For example, an LP radio device 25 in the RRC_CONNECTED state can receive such a subset identifier in a dedicated message.

[0091] In some examples, BS 30 may, for instance, pre-transmit a mapping between multiple subsets of the first contention-based uplink resource and multiple corresponding subset identifiers during a broadcast transmission. Therefore, when receiving a subset identifier of the first contention-based uplink resource from BS 30, LP radio device 25 can determine the corresponding subset of the first contention-based uplink resource that it can use. Table 1 shows an example of the mapping between multiple subsets of the first contention-based uplink resource and multiple corresponding subset identifiers that BS 30 can transmit to LP radio devices 25 within its coverage area 31. In the example in Table 1, the first contention-based uplink resource is divided into three subsets, represented by R1, R2, and R3, respectively. The identifier for subset R1 corresponds to ID1, the identifier for subset R2 corresponds to ID2, and the identifier for subset R3 corresponds to ID3. Therefore, for each subset identifier, BS 30 transmits a description of the corresponding subset of the first contention-based uplink resource.

[0092] Table 1

[0093] Subset identifier The first subset of contention-based uplink resources ID1 R1 ID2 R2 ID3 R3

[0094] Table 2 shows an example of subset identifiers sent to five LP radio devices 25, denoted as UE1, UE2, UE3, UE4 and UE5 respectively.

[0095] Table 2

[0096] LP wireless device Subset identifier UE1 ID1 UE2 ID2 UE3 ID3 UE4 ID1 UE5 ID2

[0097] Therefore, in the example in Table 2:

[0098] LP radio devices UE1 and UE4 should use the first contention-based uplink resource subset R1 (subset identifier ID1).

[0099] LP radio devices UE2 and UE5 should use the first contention-based uplink resource subset R2 (subset identifier ID2).

[0100] The LP radio device UE5 should use the first contention-based uplink resource subset R3 (subset identifier ID3).

[0101] In other examples, a subset of the first contention-based uplink resources available to a particular LP radio device 25 may be directly selected by that particular LP radio device 25. For example, an LP radio device 25 that has already received (e.g., in a broadcast transmission by BS 30) a description of multiple subsets of the first contention-based uplink resources from BS 30 may randomly select one of the subsets when it needs to transmit information related to its LP-WUR 254. Based on the previously received description of the subsets of the first contention-based uplink resources, such random selection can be performed in any RRC state of the LP radio device 25, including when the LP radio device 25 is in the RRC_IDLE state.

[0102] In some examples, BS 30 may transmit a mapping between multiple subsets of the first contention-based uplink resources and multiple corresponding numerical ranges for each LP radio device 25 to select a subset of the first contention-based uplink resources. In this case, LP radio device 25 may randomly select values, and it may select a subset of the first contention-based uplink resources associated with the range to which the selected value belongs. Such features may be used, for example, to introduce ranges of different sizes, such that the subset with the largest associated numerical range has a greater probability of being selected than other subsets. For example, the size of the numerical range may be set according to the corresponding size of the different subsets of the first contention-based uplink resources. For example, the size of the numerical range set for a given subset may be proportional to the size of the subset (i.e., proportional to the number of uplink resources that make up the subset).

[0103] Table 3 shows an example of a mapping between multiple numerical ranges and corresponding subsets R1, R2, and R3 of the first contention-based uplink resources that can be transmitted by the BS 30 to the LP radio device 25 within its coverage area 31. In the example in Table 3, the different ranges are defined by different values ​​V1, V2, and V3, such that 0 < V1 < V2 < V3. Therefore, if the LP radio device 25 selects a value between V1 and V2, it will use the first contention-based resource subset R2 to transmit information related to its LP-WUR254.

[0104] Table 3

[0105] Numerical range The first subset of contention-based uplink resources 0 to V1 R1 V1 to V2 R2 V2 to V3 R3

[0106] As discussed above, Figure 5 The 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 LP wireless device 25.

[0107] like Figure 5 As shown, the method 50 for exchanging data includes step S50: receiving, by the LP radio device 25, a description of the allocated first contention-based resource (sent by the BS during step S42), and step S51: receiving, by the LP radio device 25, a description of the second contention-based uplink resource (sent by the BS during step S43).

[0108] like Figure 5As shown, when the LP wireless device 25 needs to send information related to its LP-WUR 254 to the BS 30, the data exchange method 50 includes step S52: sending a message including the information related to the LP-WUR 254 of the LP wireless device to the BS 30 using a first contention-based uplink resource. For example, the information related to the LP-WUR 254 of the wireless device can be sent by the LP-WUR 254 (provided that the LP-WUR 254 has the transmission capability) or by the MR unit 253.

[0109] As discussed above, information related to the LP-WUR of the PL radio device may include a wake-up signal monitoring status, indicating whether wake-up signal monitoring is activated or deactivated at the LP radio device 25. The transmission of information related to the LP-WUR 254 can use any suitable format. In some examples, the LP-WUR-related information can be sent in the Media Access Control (MAC) control element (CE), for example, when the LP radio device 25 is in the RRC_CONNECTED state. For example, the LP-WUR-related information can be included in the payload of the MAC CE, or the information can be encoded in the Logical Channel Identifier (LCID) field of the MAC CE. In practice, the LCID field can take different values, some of which are currently reserved for future use. Therefore, some of these reserved LCID values ​​can be used to encode information related to the LP-WUR 254. For example, one LCID value can be used to indicate that wake-up signal monitoring is activated at the LP radio device 25, and another different LCID value can be used to indicate that wake-up signal monitoring is deactivated at the LP radio device 25. As discussed above, the MAC CE may also include an identifier for the LP radio device 25, such as the cell radio network temporary identifier (C-RNTI) of the LP radio device 25.

[0110] exist Figure 5 In the example, it is assumed in a non-restrictive manner that the first contention-based uplink resource is divided into multiple subsets. Therefore, the method 50 for exchanging data includes step S53: selecting a subset from the multiple subsets of the first contention-based uplink resource, and step S52: using the selected subset of the first contention-based uplink resource to send information related to the LP-WUR.

[0111] As discussed above, the LP radio device 25 may select the subset to use, for example, based on a subset identifier previously received from the BS 30, or it may select the subset randomly (possibly based on a mapping between multiple subsets of the first contention-based uplink resources and multiple corresponding numerical ranges, for example, a previously configured mapping previously received from the BS 30).

[0112] Schedule request resources

[0113] Figure 6 A diagram illustrating the steps of an exemplary embodiment of a method 60 for exchanging data, implemented by BS 30. Figure 7 The diagram illustrates the corresponding steps of an exemplary embodiment of a method 70 for exchanging data implemented by the wireless device 25 of the UE 20.

[0114] like Figure 6 As shown, the method 60 for exchanging data includes step S60: allocating scheduling request SR resources to wireless device 25.

[0115] Such SR resources are dedicated to a given wireless device and therefore cannot be used by other wireless devices. These SR resources may, for example, be allocated by BS 30 to wireless device 25 in either the RRC_CONNECTED or RRC_INACTIVE state. Essentially, an SR message is a physical layer message that wireless device 25 can send in an SR resource to notify BS 30 that the wireless device has UL data to send. In response to receiving an SR message from wireless device 25, BS 30 may send a UL authorization to wireless device 25.

[0116] like Figure 6 As shown, the method 60 for exchanging data then includes step S61: sending a description of the SR resources allocated to the wireless device 25 by the BS 30 to the wireless device 25.

[0117] like Figure 6 As shown, the method 60 for exchanging data then includes step S62: receiving an SR message from the wireless device 25 and in the SR resources allocated to the first wireless device 25, the SR message including information related to the LP-WUR 25 of the wireless device 25. The BS 30 receiving the SR message from the wireless device 25 can determine, for example, which specific wireless device 25 has sent the SR message based on the SR-specific resources used, and thus can identify the specific wireless device 25 to which the received LP-WUR related information applies.

[0118] Therefore, information related to LP-WUR 254 is received by sending SR messages using pre-allocated resources, so that no specific signaling overhead is required to obtain resources for sending such LP-WUR related information, thereby limiting the power consumption of the wireless device 25.

[0119] As discussed above, BS 30 can then control the transmission of a wake-up signal to wireless device 25 based on the received information related to the LP-WUR 254 of wireless device 25. For example, if wireless device 25 indicates that it has activated monitoring of the wake-up signal (e.g., due to a transition to a low-power operating mode), BS 30 can enable the transmission of the wake-up signal to wake up the MR unit 253 of wireless device 25 if necessary.

[0120] As discussed above, Figure 7 The diagram illustrates corresponding steps of an exemplary embodiment of a method 70 for exchanging data, which can be implemented in BS 30. Figure 6 The method 60 for exchanging data shown is implemented by the wireless device 25.

[0121] like Figure 7 As shown, the method 70 for exchanging data includes step S70: the wireless device 25 receives a description of the allocated SR resources sent by the BS 30 during step S61.

[0122] like Figure 7 As shown, when the wireless device 25 needs to send information related to its LP-WUR 254 to the BS 30, the data exchange method 70 includes step S71: sending an SR message containing the information related to the wireless device's LP-WUR 254 to the BS 30 using the allocated SR resources. For example, the information related to the wireless device's LP-WUR 254 can be sent by the LP-WUR 254 itself (provided that the LP-WUR 254 has a transmission capability) or by the MR unit 253.

[0123] As discussed above, information related to the LP-WUR of the wireless device may include a wake-up signal monitoring status, indicating whether wake-up signal monitoring is activated or deactivated at the wireless device 25. The transmission of information related to the LP-WUR 254 can use any suitable format. For example, a single bit can be added to the SR message to encode, for example, the wake-up signal monitoring status of the LP-WUR 254 of the wireless device 25. For instance, a bit value '1' can be used to indicate that wake-up signal monitoring is activated at the LP wireless device 25, and a bit value '0' can be used to indicate that wake-up signal monitoring is deactivated at the LP wireless device 25. Therefore, in some examples, LP-WUR-related information may include a single bit, thus limiting signaling overhead and power consumption of the wireless device 25.

[0124] It should be emphasized that this disclosure is not limited to the exemplary embodiments described above. Variations of the exemplary embodiments described above are also within the scope of this disclosure.

[0125] For example, the present invention has been described primarily by considering LP-WUR-related information, including the wake-up signal monitoring status of the LP-WUR 254. In other examples, other types of LP-WUR-related information may also be considered alternatively or in combination. For example, information indicating the duration for which wake-up signal monitoring will be activated, information indicating the received level of the wake-up signal, etc., may be transmitted.

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 includes a main radio (MR) unit (253) and a low-power wake-up receiver (LP-WUR) (254), the MR unit being configured to exchange data with a radio access network (RAN) of the wireless communication system, the LP-WUR being configured to detect a wake-up signal transmitted by the RAN and, in response to detecting the wake-up signal transmitted by the RAN, trigger a transition of the MR unit from a very low-power state to an active state, wherein the method includes: (S52) Information related to the LP-WUR is sent to the RAN by using a first contention-based uplink resource, wherein the first contention-based uplink resource is independent of a second contention-based uplink resource used to send information unrelated to the LP-WUR.

2. The method (50) according to claim 1, wherein the second contention-based uplink resource includes a random access channel (RACH) resource, which is provided by the MR unit for establishing communication with the RAN.

3. The method (50) according to any one of the preceding claims, wherein the second contention-based uplink resource includes a common configuration license (CG) uplink resource, the CG uplink resource being used by the MR to transmit information unrelated to the LP-WUR, and the first contention-based uplink resource corresponding to a separate common CG uplink resource being used by the wireless device to transmit information related to the LP-WUR.

4. The method (50) according to claim 3, wherein the information related to the LP-WUR is sent in the Media Access Control (MAC) control element (CE).

5. The method (50) of claim 4, wherein information related to the LP-WUR is encoded in the logical channel identifier (LCID) field of the MACCE.

6. The method (50) according to any one of the preceding claims, wherein the first contention-based uplink resource is divided into multiple subsets, and the method comprises: (S53) Select a subset from the multiple subsets of the first contention-based uplink resources. (S52) Send information related to the LP-WUR by using the selected subset.

7. The method (50) of claim 6, wherein the subset to be used is randomly selected from a plurality of subsets of the first contention-based uplink resources.

8. The method (50) of claim 6, wherein the subset to be used is selected based on a subset identifier received from the RAN.

9. The method (50) according to any one of the preceding claims, wherein the information related to the LP-WUR transmitted by using the first contention-based uplink resource includes the wake-up signal monitoring status of the LP-WUR.

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

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

12. 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 plurality of wireless devices, at least some of which are low-power LP wireless devices (25), wherein each LP wireless device (25) includes a main radio MR unit (253) and a low-power wake-up receiver (LP-WUR) (254), wherein the LP-WUR is configured to detect a wake-up signal transmitted by the BS and, in response to detecting the wake-up signal transmitted by the BS, trigger a transition of the MR unit from a low-power state to an active state, wherein the method includes: (S40) Allocate a first contention-based uplink resource to the LP radio device, the first contention-based uplink resource being used by the LP radio device to transmit information related to their LP-WUR. (S41) Allocate a second contention-based uplink resource to the wireless device, the second contention-based uplink resource being used by the wireless device to transmit information unrelated to the LP-WUR, wherein the second contention-based uplink resource is independent of the first contention-based uplink resource.

13. The method (40) of claim 12, wherein the second contention-based uplink resource includes a random access channel (RACH) resource, the RACH resource being used by the radio device to establish communication with the BS.

14. The method (40) according to any one of claims 12 to 13, wherein the second contention-based uplink resource includes a common configuration license (CG) uplink resource for the radio device to transmit information unrelated to the LP-WUR, and the first contention-based uplink resource corresponds to a separate common CG uplink resource for the LP radio devices to transmit information related to their LP-WUR.

15. The method (40) according to any one of claims 12 to 14, wherein the first contention-based uplink resource is divided into a plurality of subsets.

16. The method (40) according to claim 15, comprising: The mapping between multiple subsets of the first contention-based uplink resources and multiple corresponding subset identifiers is sent to the LP radio device, and a subset identifier of the subset of the first contention-based uplink resources available for use by the LP radio device is sent to each LP radio device.

17. The method (40) according to claim 15, comprising: A mapping is sent to the LP radio device between multiple subsets of the first contention-based uplink resources and multiple corresponding numerical ranges for each LP radio device to select a subset of the first contention-based uplink resources.

18. The method (40) according to any one of claims 12 to 17, wherein the information related to the LP-WUR transmitted by using the first contention-based uplink resource includes the wake-up signal monitoring status of the LP-WUR.

19. 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 perform the method (40) according to any one of claims 12 to 18.

20. A wireless communication system comprising at least one base station (30) according to claim 19 and at least one user equipment (20) according to claim 11.

21. A computer program product (252, 302) comprising instructions that, when executed by at least one processor, configure the at least one processor to perform the method (50) according to any one of claims 1 to 9 or the method (40) according to any one of claims 12 to 18.

22. 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 (50) according to any one of claims 1 to 9 or the method (40) according to any one of claims 12 to 18.

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