Switching between wake-up times for lower power wake up mode

Abstract

Switching between wake-up times for lower power wake up mode 600, comprising the first apparatus 110 obtaining a first and second minimum time gaps 605, 606 between a respective first and second time

Description

[0002] The cellular communications technology and new radio (NR) developed in the third-generation partnership project (3GPP) offers increased performance and a wide range of services (e.g., ultra-reliable low-latency communications, URLLC). Besides latency, reliability, and availability, UE energy efficiency is also critical to the cellular communications. Currently, the wireless devices may have to be recharged per week or day, depending on individual’s usage time. In general, wireless devices consume tens of milliwatts in radio resource control (RRC) idle / inactive state and hundreds of milliwatts in RRC connected state. Design to prolong battery life is a necessity for improving energy efficiency as well as for better user experience. SUMMARY

[0003] In a first aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to: obtain a first minimum time gap between a first time period for monitoring a low-power wake-up signal, LP WUS, and an on-duration for a first discontinuous reception, DRX, cycle, and a second minimum time gap between a second time period for monitoring a LP WUS and an on-duration for a second DRX cycle, the second minimum time gap being different from the first minimum time gap; monitor the LP WUS from a second apparatus within the first time period before the first minimum time gap; and monitor the LP WUS from the second apparatus within the second time period before the second minimum time gap.

[0004] In a second aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus at least to: determine a first minimum time gap between a first time period for a low-power wake-up signal, LP WUS, and an on-duration for a first discontinuous reception, DRX, cycle, and a second minimum time gap between a second time period for a LP WUS and an on-duration for a second DRX cycle for a second apparatus, the second minimum time gap being different from the first minimum time gap; and determine whether to transmit a LP WUS during the first time period and the second time period to the first apparatus based on the first minimum time gap and the second minimum time gap.

[0005] In a third aspect of the present disclosure, there is provided a method. The method comprises: obtaining a first minimum time gap between a first time period for monitoring a low-power wake-up signal, LP WUS, and an on-duration for a first discontinuous reception, DRX, cycle, and a second minimum time gap between a second time period for monitoring a LP WUS and an on-duration for a second DRX cycle, the second minimum time gap being different from the first minimum time gap; monitoring the LP WUS from a second apparatus within the first time period before the first minimum time gap; and monitoring the LP WUS from the second apparatus within the second time period before the second minimum time gap.

[0006] In a fourth aspect of the present disclosure, there is provided a method. The method comprises: determining a first minimum time gap between a first time period for a low-power wake-up signal, LP WUS, and an on-duration for a first discontinuous reception, DRX, cycle, and a second minimum time gap between a second time period for a LP WUS and an on-duration for a second DRX cycle for a second apparatus, the second minimum time gap being different from the first minimum time gap; and determining whether to transmit a LP WUS during the first time period and the second time period to the first apparatus based on the first minimum time gap and the second minimum time gap-

[0007] In a fifth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for obtaining a first minimum time gap between a first time period for monitoring a low-power wake-up signal, LP WUS, and an on-duration for a first discontinuous reception, DRX, cycle, and a second minimum time gap between a second time period for monitoring a LP WUS and an on-duration for a second DRX cycle, the second minimum time gap being different from the first minimum time gap; means for monitoring the LP WUS from a second apparatus within the first time period before the first minimum time gap; and means for monitoring the LP WUS from the second apparatus within the second time period before the second minimum time gap.

[0008] In a sixth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises means for determining a first minimum time gap between a first time period for a low-power wake-up signal, LP WUS, and an on-duration for a first discontinuous reception, DRX, cycle, and a second minimum time gap between a second time period for a LP WUS and an on-duration for a second DRX cycle for a second apparatus, the second minimum time gap being different from the first minimum time gap; and means for determining whether to transmit a LP WUS during the first time period and the second time period to the first apparatus based on the first minimum time gap and the second minimum time gap.

[0009] In a seventh aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the third aspect.

[0010] In an eighth aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the fourth aspect.

[0011] It is to be understood that the Summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Some example embodiments will now be described with reference to the accompanying drawings, where:

[0013] FIG. 1A illustrates an example communication environment in which example embodiments of the present disclosure can be implemented;

[0014] FIG. IB illustrates a schematic diagram of operations of a terminal device with low-power wake-up receiver (WUR) based on which example embodiments of the present disclosure may be implemented;

[0015] FIG. 2 illustrates an example showing how the network uses downlink control information, DCI, as a wake-up signal;

[0016] FIG. 3 illustrates a signaling flow for minimum time gap capability reporting in accordance with some example embodiments of the present disclosure;

[0017] FIG. 4 illustrates example DRX configurations in accordance with some example embodiments of the present disclosure;

[0018] FIG. 5 illustrates a signaling flow for synchronization capability reporting in accordance with some example embodiments of the present disclosure;

[0019] FIG. 6 illustrates a signaling flow for dynamic switching of LP-WUS wake-up times in accordance with some example embodiments of the present disclosure;

[0020] FIG. 7A illustrates a flowchart of a method implemented at a first apparatus in accordance with some example embodiments of the present disclosure;

[0021] FIG. 7B illustrates a flowchart of a method implemented at a second apparatus in accordance with some example embodiments of the present disclosure;

[0022] FIG. 8A illustrates a flowchart of a method implemented at a first apparatus in accordance with some other example embodiments of the present disclosure;

[0023] FIG. 8B illustrates a flowchart of a method implemented at a second apparatus in accordance with some other example embodiments of the present disclosure;

[0024] FIG. 9A illustrates a flowchart of a method implemented at a first apparatus in accordance with some further example embodiments of the present disclosure;

[0025] FIG. 9B illustrates a flowchart of a method implemented at a second apparatus in accordance with some further example embodiments of the present disclosure;

[0026] FIG. 10 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

[0027] FIG. 11 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

[0028] Throughout the drawings, the same or similar reference numerals represent the same or similar element. DETAILED DESCRIPTION

[0029] Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. Embodiments described herein can be implemented in various manners other than the ones described below.

[0030] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

[0031] References in the present disclosure to “one embodiment,” “an embodiment,” “an example embodiment,” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0032] It shall be understood that although the terms “first,” “second,”..., etc. in front of noun(s) and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another and they do not limit the order of the noun(s). For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0033] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0034] As used herein, unless stated explicitly, performing a step “in response to A” does not indicate that the step is performed immediately after “A” occurs and one or more intervening steps may be included.

[0035] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the 5 terms “comprises”, “comprising”, “has”, “having”, “includes” and / or “including”, when used herein, specify the presence of stated features, elements, and / or components etc., but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof.

[0036] As used in this application, the term “circuitry” may refer to one or more or all 10 of the following: (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and (b) combinations of hardware circuits and software, such as (as applicable): (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0037] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) 15 accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0038] As used herein, the term “communication network” refers to a network following any suitable communication standards, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G), the second generation (2G), 2.5G, 2.75G, the third generation (3G), the fourth generation (4G), 4.5G, the fifth generation (5G), the sixth generation (6G) communication protocols, and / or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

[0039] As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, an Integrated Access and Backhaul (IAB) node, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, and so forth, depending on the applied terminology and technology. In some example embodiments, radio access network (RAN) split architecture comprises a Centralized Unit (CU) and a Distributed Unit (DU) at an IAB donor node. An IAB node comprises a Mobile Terminal (IAB-MT) part that behaves like a UE toward the parent node, and a DU part of an IAB node behaves like a base station toward the next-hop IAB node.

[0040] The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE), a Subscriber Station (SS), a Portable Subscriber Station, a Mobile Station (MS), or an Access Terminal (AT). The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), USB dongles, smart devices, wireless customer-premises equipment (CPE), an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. The terminal device may also correspond to a Mobile Termination (MT) part of an IAB node (e.g., a relay node). In the following description, the terms “terminal device”, “communication device”, “terminal”, “user equipment” and “UE” may be used interchangeably.

[0041] As used herein, the term “resource,” “transmission resource,” “resource block,” “physical resource block” (PRB), “uplink resource,” or “downlink resource” may refer to any resource for performing a communication, for example, a communication between a terminal device and a network device, such as a resource in time domain, a resource in frequency domain, a resource in space domain, a resource in code domain, or any other combination of the time, frequency, space and / or code domain resource enabling a communication, and the like. In the following, unless explicitly stated, a resource in both frequency domain and time domain will be used as an example of a transmission resource for describing some example embodiments of the present disclosure. It is noted that example embodiments of the present disclosure are equally applicable to other resources in other domains.

[0042] FIG. 1A illustrates a schematic diagram of an example communication environment 100 in which example embodiments of the present disclosure can be implemented. In the communication environment 100, a plurality of communication devices, including a terminal device 110 and a network device 120, can communicate with each other.

[0043] In the example of FIG. 1, the terminal device 110 may be a UE and the network device 120 may be a base station serving the UE. The serving area of the network device 120 may be called a cell 102. The network device 120 is operating in a radio access network (RAN) and thus is also referred to as a RAN network device.

[0044] In some example embodiments, the RAN architecture will include a centralized part, or central unit (CU), and a distributed part, or distributed unit (DU). The CU and the DU will be connected to one another by a so-called Fl interface. In some example embodiments, the CU may be split into a CU-UP (central unit-user plane) and a CU-CP (central unit-control plane). The CU-UP and the CU-CP will be connected to one another by a so-called El interface, and the Fl interface will be split between Fl-c and Fl-u interfaces for the control and user planes, respectively.

[0045] It is to be understood that the number of devices and their connections shown in FIG. 1 are only for the purpose of illustration without suggesting any limitation. The communication environment 100 may include any suitable number of devices configured to implementing example embodiments of the present disclosure. Although not shown, it would be appreciated that one or more additional devices may be located in the cell 102, and one or more additional cells may be deployed in the communication environment 100. It is noted that although illustrated as a network device, the network device 120 may be another device than a network device. Although illustrated as a terminal device, the terminal device 110 may be another device than a terminal device.

[0046] In the following, for the purpose of illustration, some example embodiments are described with the terminal device 110 operating as a UE and the network device 120 operating as a base station, e.g., gNB. However, in some example embodiments, operations described in connection with a terminal device may be implemented at a network device or other device, and operations described in connection with a network device may be implemented at a terminal device or other device.

[0047] In some example embodiments, a link from the network device 120 to the terminal device 110 is referred to as a downlink (DL), while a link from the terminal device 110 to the network device 120 is referred to as an uplink (UL). In DL, the network device 120 is a transmitting (TX) device (or a transmitter) and the terminal device 110 is a receiving (RX) device (or a receiver). In UL, the terminal device 110 is a TX device (or a transmitter) and the network device 120 is a RX device (or a receiver).

[0048] Communications in the communication environment 100 may be implemented according to any proper communication protocol(s), comprising, but not limited to, cellular communication protocols of the first generation (1G), the second generation (2G), the third generation (3G), the fourth generation (4G), the fifth generation (5G), the sixth generation (6G), and the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and / or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiple (OFDM), Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and / or any other technologies currently known or to be developed in the future.

[0049] Energy efficiency is even more critical for UE without a continuous energy source, e.g., UE using small rechargeable and single coin cell batteries. The power consumption depends on the configured length of wake-up periods, e.g., paging cycle. To meet the battery life requirements above, eDRX cycle with large value is expected to be used, resulting in high latency, which is not suitable for such services with requirements of both long battery life and low latency. A UE architecture is proposed by using a wakeup signal to trigger the main radio and a separate receiver which has the ability to monitor wake-up signal with ultra-low power consumption. Main radio (also referred to as main transceiver) works for data transmission and reception, which can be turned off or set to deep sleep unless it is turned on. The power consumption for monitoring wake-up signal depends on the wake-up signal design and the hardware module of the wake-up receiver used for signal detecting and processing.

[0050] FIG. IB illustrates a schematic diagram of operations of a terminal device 110 with low-power wake-up receiver (WUR) based on which some example embodiments of the present disclosure may be implemented. Such a terminal device 110 primarily targets low-power WUS / WUR for power-sensitive, small form-factor devices such as loT devices (e.g., industrial sensors, or controllers) and wearables. Other use cases are not precluded, e.g., extended reality (XR), smart glasses, or smart phones. As illustrated in FIG. IB, the terminal device 110 includes a main radio (MR) 112 and a separate receiver, i.e., an ultralow power wake-up receiver (LP-WUR) 114. The main radio 112 may include a transceiver for transmission and / or reception.

[0051] The main radio 112 of the terminal device 110 may be in a sleep mode (or even powered off) for power saving when not being needed for any processing (e.g., traffic / measurements) and be activated only upon the reception of the wake-up signal (WUS) from the network (e.g., from a network device). The network may trigger the terminal device 110 to wake-up when needed in an event-driven manner, by transmitting a special WUS to the terminal device 110, which is monitored by the dedicated low-power WUS receiver 114 at the terminal device 110. When the terminal device 110 receives the WUS, the WUS receiver 114 can trigger the wake-up of the ordinary transceiver (which is included in the main radio 112) and communication can start. Thus, the ultra-low power wake-up receiver 114 wakes up the main radio 112 and otherwise, the main radio 112 is OFF or kept in a deep sleep mode, as shown in FIG. IB. The assumption is that the low-power wake-up receiver can be operated in an always ‘on’ manner with very low power consumption. In fact, it is expected that it will consume significantly less power compared to the transceiver, by designing a simple (WUS) signal and the use of dedicated hardware for its monitoring, which is only able to receive the WUS.

[0052] The Discontinuous Reception (DRX) mechanism is designed by for power saving in the communication systems. It is also proposed an advanced signal called Downlink Control Information of Power Saving (DCP) or DRX-adaption.

[0053] FIG. 2 illustrates how the network uses downlink control information, DO, (format 2 6. i.e., DCI 2 6) as a wake-up signal. The DRX configuration for the terminal device is a long DRX cycle configuration 210, e.g., with on-duration (OnDuration) 220, 220, and etc. In long DRX cycle execution 240, the terminal device monitors a preconfigured specific wake-up signal window 250 ahead of a long DRX on-duration 220 for this wake-up signal.

[0054] If the terminal device detects no DCI wake up signal in the window 250, it assumes no traffic in the next ONDuration 220 and conserves main radio power by not monitoring for traffic in the next ONDuration 220. If the terminal device detects the DCI2 6 with a wake-up signal in a wake-up signal window 270, then the terminal device may trigger the main radio / receiver in the next ONDuration 220, and UE energy may be consumed.

[0055] For a network to configure the wake-up signal feature for a terminal device, it needs to determine that the terminal device supports this feature and a parameter of minimum time gap “MinTimeGap” that the terminal device can support. This “MinTimeGap” parameter that accounts for the time needed by a terminal device to process the wake-up signal and wake the terminal device into a state where it is fully ready to monitor for the OnDuration when a positive wake-up signal is processed.

[0056] In some embodiments, the network device may determine if a terminal device supports the wake-up signal feature using the UE capability enquiry procedure. In the UE capability enquiry procedure, the network device may transmit a UE capability enquiry to the terminal device to request for UE capabilities, and the terminal device may respond with UE capability information.

[0057] In some examples, the network device may request for UE capabilities during the registration procedure. In this case, the network may then store the UE capabilities locally. This means that the UE may not need to send UE capabilities every time the RRC connection is established or re-established. In some examples, the network device may request for UE capabilities at any time during RRC connected state. In some other examples, if the terminal device changes its radio capabilities, the terminal device may initiate a Tracking Area Updating (TAU) procedure and include the IE UE radio capability information update needed in the TAU request message. The network device may then request for new UE capabilities from the terminal device.

[0058] In some embodiments, the UE capability information may indicate capability information about the “MinTimeGap” parameter. The MinTimeGap parameter for DRX is determined based on the subcarrier spacing (SCS) numerology. For a given subcarrier spacing numerology, the terminal device may inform the network device with one of two predefined values, for the minimum amount of time it needs to ramp up the main radio to be fully ready to process the next ONDuration. For example, for SCS = 15kHz, this value can be either 1 slot (1ms) or 3 slots (3 ms) and for SCS=120 kHz, this can be either 2 slots (0.25 ms) or 24 slots (3.0 ms).

[0059] It can be seen that the MinTimeGap parameter for DRX is defined in terms of slot durations and is defined per SCS. Each SCS has its own slot duration, and only 2 values defined per SCS. The maximum is common for all SCS, e.g., 3 ms. The minimum may not fall below 0.25 ms if that corresponds to 1 or more slots. SCS 120kHz has slot duration = 125us hence 2 slots = 0.25ms.

[0060] As mentioned earlier, a new signal with a new and separate low power receiver is now exploited to allow the main radio to be powered down to a much deeper and low power sleep mode, meaning that it will require far more time to wake up and be ready for the ONDuration (to monitor physical downlink control channel, PDCCH).

[0061] In some embodiments, different sleep states (or sleep modes) may be defined for a terminal device. In some cases, values ranging from 0ms and 20ms may be used for connected mode power savings analysis. For example, the sleep states considered for LP WUS / WUR evaluation in RRCCONNECTED mode may be defined as a deep sleep state with a 20 ms transition time to a wake up state, a light sleep state with a 6 ms transition time to a wake up state, and a micro sleep without any transition time to a wake up state.

[0062] For the deepest and most power saving mode, the ultra-deep sleep state, may be difficult to be defined for LP-WUS / WUR in RRC CONNECTED state as a 400 ms transition time is too long to allow the MR to be ready for PDCCH monitoring from the ultra-deep sleep state considering the traffic requirements. Therefore, the power saving gain for LP-WUS / WUR would be determined by the time duration in which the MR can be kept in a sleep state, and significantly lower power consumed by LP WUS / LP WUR compared to the PDCCH monitoring by MR. Regarding latency, the transition time for the MR to start up upon LP-WUS detection by LP-WUR may not be worse comparing to the existing power saving mechanism since the MR could be in micro, light, or deep sleep state as legacy, but is not allowed to be in ultra-deep sleep state when LR is monitoring LP-WUS, as described above.

[0063] The power saving modes may work with the DRX mechanism. Some typical DRX configurations may include a long DRX cycle time (e.g., 160 or 320 ms), a relatively small on-duration (e.g., 8 or 10 ms), and a relatively large inactivity timer (e.g., 80 or 100 ms). It can be observed from the DRX configurations that the effective “off-duration” or “off-period” may vary dramatically due to the use of the particularly long inactivity timers. For example, if a DRX configuration with a DRX cycle time of 160 ms, an on-duraiton of 10 ms, and an inactivity timer of 100 ms, the effective “off-duration” may vary from 150ms to only 50ms, depending on whether the inactivity timer is applied.

[0064] Another procedure, similar to the UE capability procedure, that may be applied by the UE to support other power saving features, is the UE assistance procedure. In the UE assistance procedure, the terminal device reports UE assistance information after the RRC connection is established. The UE capability information may be considered as a set of static information whereas UE assistance information may be of dynamic nature. In addition, the UE assistance information may be sent when the UE needs. The purpose of this procedure is to inform the network of UE assistance information, including but not limited to, power saving preference, SPS assistance information, maximum physical downlink shared channel (PDSCH) / physical uplink shared channel (PUSCH) bandwidth configuration preference, overheating assistance information, or the delay budget report carrying desired increment / decrement in the Uu air interface delay, or connected mode DRX cycle length, or the like.

[0065] Upon configuring the terminal device to provide power preference indications, the network device may consider that the terminal device does not prefer a configuration primarily optimized for power saving until the terminal device explicitly indicates otherwise.

[0066] Examples of how a UE uses this procedure to inform the network of some preferences may include a parameter “MaxMIMO-LayerPreference-rl6” which is sent when the terminal device reports the MIMO configuration less than what it has reported in UE capability information and it is expected for the network to send RRC reconfiguration information to downgrade the MIMO as reported; a parameter “reducedMaxCCs” which is sent when the terminal device would report less component carriers (CCs) than the number of CCs in the current setup and it is expected for the network device to reduce the number of CCs.

[0067] By analyzing the current procedures supported for the DRX, it needs to configure the minimum time gap between LP-WUS reception and the MR to start PDCCH monitoring.

[0068] The period between when the LP-WUS is successfully detected and the time when the main radio can start monitoring for PDCCH traffic may vary depending on several factors including the main radio wake up time, and the time required by the main radio to synchronize after it wakes uped. The main radio wake up time may depend on proprietary hardware design choices for a terminal device, and the sleep mode(s) / power saving level(s) that is selected or supported by the terminal device, such as the deep sleep state, light sleep state, micro sleep state, or ultra-deep sleep state. The time required by the main radio to synchronize after it wakes uped may depend on the proprietary hardware design choices, the last synchronization event (and low drift), and / or the availability of synchronization signals configured by the network.

[0069] As the DCP feature is to be applicable to as many different use cases as possible, ranging from home utility meters, smart wearables, to tracking, safety and industrial loT devices, it can be easily envisaged that there will be numerous permutations of the following factors, including LP-WUS receiver designs, network configurations of synchronization signals, network configurations of connected mode discontinuous Reception (C-DRX) or LP-WUS (group or UE specific), device power consumption saving target, and application latency target. Any change in any of the factors above, may change the optimum (i.e. shortest / lowest latency) wake-up time that can be supported by both the network and device.

[0070] In example embodiments of the present disclosure, it proposes some solutions for reporting capabilities of minimum time gap and / or synchronization time of a terminal device based on configuration information associated with DRX. Some other solutions are proposed to support dynamic switching between a plurality of minimum time gaps for LP-WUS wake-up times.

[0071] Example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0072] FIG. 3 illustrates a signaling flow 300 for minimum time gap capability reporting in accordance with some example embodiments of the present disclosure. For the purposes of discussion, the signaling flow 300 will be discussed with reference to FIG. 1. The signaling flow 300 may involve the terminal device 110 and the network device 120 in FIG. 1.

[0073] In the signaling flow 300, the network device 120 transmits (305), to the terminal device 110, configuration information associated with a DRX procedure for the terminal device 110.

[0074] In some example embodiments, the configuration information may indicate at least one of the following: a DRX cycle time, an on-duration timer value, or an inactivity timer value. In some example embodiments, the configuration information may include connected mode DRX (cDRX) configuration information. In some examples, a DRX cycle configured according to the cDRX configuration information may be referred to as a cDRX cycle.

[0075] In some examples, the configuration information may include a plurality of DRX configurations, each DRX configuration may include a set of DRX parameters such as a DRX cycle time, an on-duration timer value, and / or an inactivity timer value. In some examples, the inactivity timer value may or may not be configured or applied for a DRX cycle. Depending on the DRX cycle time, a DRX cycle may be configured as a long DRX cycle or a short DRX cycle. It would be appreciated that the configuration information may include one or more other parameters for the DRX procedure, such as a DRX slot offset.

[0076] In some example embodiments, the configuration information in a capability request or in a channel or cell configuration for the terminal device 110. In the example embodiments of the present disclosure, the network device 120 may indicate in the capability enquiry the considered cell / channel configuration, so that terminal device 110 may report the minimum time gap capability accordingly. The capability request may include, e.g., a UE capability enquiry in the UE capability enquiry procedure. The configuration information associated with the DRX procedure may be provided to the terminal device 110 in any other appropriate ways.

[0077] In some example embodiments, the network device 120 may request the minimum time gap capability of the terminal device 110, but without consideration of network, cell, or channel configuration.

[0078] FIG. 4 illustrates an example DRX configuration 400 in accordance with some example embodiments of the present disclosure. In the long DRX cycle #n, the terminal device 110 performs PDCCH reception in an on-duration 410 with a length equal to the configured on-duration timer (represented as drx-onDuration timer). Data transmission spill over into the “non-on-duration”, i.e., the duration of the inactive period 412 with a length equal to the configured inactivity timer (represented as drx-inaclivily timer). During the off-period (after the expiration of the inactivity timer), the terminal device 110 may monitor a wake-up signal (e.g., a LP WUS) in a wake-up signal window 420 ahead of an on-duration 430 in the next long DRX cycle #n+l. Depending on whether the wakeup signal is detected in the wake-up signal window 420, the terminal device 110 may determine whether to activate the transceiver (e.g., the main transceiver 114) in the next on-duration 430. Such a wake-up signal window herein is also referred to as a time period for monitoring a LP WUS. The terminal device 110 may also monitor a wake-up signal in a wake-up signal window 440 ahead of an on-duration 450 in a next long DRX cycle.

[0079] The terminal device 110 receives (310), from the network device 120, the configuration information associated with the DRX procedure and determines (315), at least one minimum time gap based on the configuration information. A minimum time gap is between a time period for monitoring a LP WUS (i.e., the wake up signal window) and an on-duration of the DRX procedure (during which the terminal device 110 may start monitoring for PDCCH traffic). With the configuration information associated with the DRX procedure, the terminal device 110 may be able to estimate the wake up time left between successive on-durations in the DRX procedure, and determine one or more required minimum time gaps for DRX.

[0080] In the example of FIG. 4, based on the configuration of the DRX cycle value, the on-duration value, and the inactivity timer, the terminal device 110 may determine that a relatively short wake up time is left between the wake up signal window 420 and the next on-duration 430, and a relatively large wake up time is left between the wake up signal window 440 and the next on-duration 450. When facing with the relatively short wake up time, the terminal device 110 may be transitioned into a less deep sleep mode so it can transition to a wake-up state in a faster way. When facing with the relatively long wake up time, the terminal device 110 may be transitioned into a deeper sleep mode for more power saving but longer time to activate.

[0081] In some example embodiments, the terminal device 110 may determine, based on the DRX configuration(s), which one or more minimum time gaps that it can use. For example, if the terminal device 110 determines a relatively short wake up time left between the wake up signal window 420 and the next on-duration 430, the terminal device 110 may determine a minimum time gap that does not exceed the non-on-duration period (by taking the inactivity timer into account). Similarly, the terminal device 110 may determine a minimum time gap that does not exceed the time gap between successive on-durations 430 and 450 for the long DRX cycle #n+l.

[0082] In some example embodiments, the terminal device 110 may be provided with a subset of minimum time gap values, e g., in the configuration information from the network device 120. The terminal device 110 may select one or more suitable minimum time gaps from the configured subset of minimum time gap values. In some example embodiments, the network device 120 may configure a requirement for a minimum time gap, and the terminal device 110 may determine whether it meets the requirement and select the corresponding minimum time gap if the requirement is satisfied.

[0083] In some examples, the terminal device 110 may be allowed to select a relatively long minimum time gap as such a long time gap can be supported in any circumstances. The terminal device 110 may be allowed to select a relatively short minimum time gap when a corresponding requirement for such a short time gap is satisfied.

[0084] In some example embodiments, in addition to the DRX configuration, the terminal device 110 may determine a suitable minimum time gap further based on nonnetwork information. Such non-network information may include, for example, the power consumption or power level of the terminal device, the application level latency, proprietary hardware configuration options, the sleep mode(s) / power saving level(s) selected / supported by the terminal device. For example, the terminal device 110 under different circumstances, e.g., at different battery levels or different power consumption levels, may determine different minimum time gaps.

[0085] The terminal device 110 transmits (320), to the network device 120, capability information indicating the at least one minimum time gap. The at least one minimum time gap may be reported as minimum time gap capability of the terminal device 110.

[0086] In some example embodiments, the terminal device 110 may receive, from the network device 120, a request to report minimum time gap capability. In an example, the request may be in a UE capability enquiry. In some example embodiments, the configuration information associated with the DRX procedure is provided in a UE capability enquiry from the network device 120, to request for the minimum time gap capability of the terminal device 110. The terminal device 110 may report back the minimum time gap capability of the terminal device 110 in the UE capability information to the network device 120. As such, DRX configuration information (e.g., cDRX configuration information) may be introduced as part of the UE capability procedure where the network requests the minimum gap time capability of the terminal device.

[0087] In some example embodiments, the network device may request the terminal device 110 to report the minimum time gap capability for a specific target DRX cycle. The terminal device 110 may receive, from the network device 120, a request to report minimum time gap capability for the target DRX cycle. In this case, the terminal device 110 may determine, based on the configuration information, a minimum time gap between a time period for monitoring the LP WUS and an on-duration in that target DRX cycle. Then the terminal device 110 may transmit, to the network device 120, the capability information indicating the determined minimum time gap for the target DRX cycle.

[0088] In some example embodiments, the network device 120 may request the terminal device 110 to report the capability that is applicable up to a certain target DRX cycle(s), or below certain target DRX cycle(s). The terminal device 110 may determine, based on the configuration information, at least one first minimum time gap applicable to a first target DRX cycle with a first DRX configuration and / or at least one second minimum time gap applicable to a second target DRX cycle with a second DRX configuration different from the first DRX configuration. Then the terminal device 110 may transmit, to the network device 120, the capability information indicating the at least one first minimum time gap and / or the at least one second minimum time gap.

[0089] As the DRX configurations are different, different minimum time gaps may be determined for the respective DRX cycles. As shown in the example of FIG. 4, the minimum time gap determined for the long DRX cycle #n may be different from the minimum time gap determined for the long DRX cycle #n+l.

[0090] In some example embodiments, the terminal device 110 may receive, from the network device 120, a request to minimum time gap capability for the first target DRX cycle and the second target DRX cycle. The terminal device 110 may determine the different minimum time gaps for the different DRX cycles as requested by the network device 120.

[0091] In some example embodiments, the terminal device 110 may determine and transmit, to the network device 120, the capability information indicating a minimum time gap corresponding to an ultra-deep sleep mode of the terminal device 110 and a minimum time gap corresponding to a sleep mode of the terminal device 110. The minimum time gap corresponding to the ultra-deep sleep mode may be a relatively long time gap, e.g., the longest minimum time gap configured to be applicable by the terminal device 110. In this case, the relatively long minimum time gap (e.g., long-minTimeGap-R19) may be used for maximum power savings. On the other hand, the minimum time gap corresponding to a non-deep sleep mode of the terminal device may be a relatively short time gap, e.g., a shortest minimum time gap configured to be applicable by the terminal device 110. In this case, the relatively short minimum time gap (e.g., short-minTimeGap-R19) may be used by the terminal device 110, to indicate the time gap it needs to justify using the LP WUS for power saving.

[0092] In some examples, an end point of a minimum time gap may be defined as the beginning of the slot where the terminal device may start the on-duration timer (e.g., drx-onDurationTimer) or start PDCCH monitoring. This follows the convention adopted for the definition of the Release-16 minTimeGap. In some examples, a start point of the minimum time gap may be defined as the end of the slot of the final transmission of the WUS. This start point is independent of the length of the WUS, which may vary between one or more slots depending on the payload and modulation scheme and may not use all symbols within a slot.

[0093] As an alternative, the start point of the minimum time gap may be defined as the start of the slot of the first transmission of the WUS. This start point is independent of the device implementation on how many WUS bits it requires to successfully detect and / or decode the WUS, as some device implementation may allow early decision without waiting for the final transmission of the WUS. The end point of the minimum time gap may be defined as the beginning of the slot where the terminal device may start the on-duration timer (e.g., drx-onDurationTimer) or start PDCCH monitoring. This follows the convention adopted for the definition of the Release-16 minTimeGap.

[0094] In some example embodiments, the terminal device 110 may report to the network device in the capability information a plurality of separate sets of minimum time gaps according to a shared spectrum channel access mode.

[0095] The network device 120 receives (325), from the terminal device 110, the capability information of the terminal device 110. The network device 120 performs (330) a communication with the terminal device 110 in the DRX procedure based on the received capability information. The network device 120 may schedule the LP WUS and / or PDCCH traffic based on the minimum time gap capability reported by the terminal device 110.

[0096] With the capability information about the minimum time gaps, it may avoid the configuration of LP WUS when the required minimum time gap of the terminal device 110 exceeds the time between successive on-durations (which may be hereafter referred to as off-duration).

[0097] In some example embodiments, with the capability information about the minimum time gap capability of the terminal device, the network device 120 may update the configuration information associated with the DRX procedure for the terminal device 110. For example, the network device 120 may optimize the DRX configuration(s), e.g., adjust one or more of the DRX parameters, to maximise UE power savings using the LP WUS or alternatively disable the LP WUS.

[0098] In some example embodiments, if group-WUS is being used, the network device 120 may transmit a LP WUS to a group of UEs comprising the terminal device 110. The groups of UEs may include those reporting the same or similar minimum time gap values.

[0099] In some example embodiments, the network device 120 may adjust a data transmission in an on-duration of the DRX procedure for the terminal device 110. For example, the network device 120 may dynamically shorten or buffer data transmissions to ensure that the terminal device 110 is able to exploit the long minimum time gap. As another example, the network device 120 may dynamically lengthen data transmissions to ensure that the terminal device 110 is able to exploit the short minimum time gap.

[0100] In some example embodiments, the network device 120 may configure a minimum time gap that is anywhere between the values indicated by the terminal device 110. This could be very useful in helping the network to group UEs to use the same group LP-WUS signal.

[0101] In some example embodiments, if the LP-WUS operation is not possible, the terminal device may enable PDCCH monitoring in the on-duration configured for the DRX procedure as per legacy. The LP-WUS operation may be automatically resumed during the next “non-ONDuration” period that exceeds the minimum time gap reported by the terminal device.

[0102] In some example embodiments, when determining a minimum time gap, the terminal device 110 may account for the time required to resynchronize a transceiver (e.g., the MR) of the terminal device 110. The transceiver (e.g., the MR) of the terminal device 110 is deactivated in the sleep mode and require some time to synchronize after it wakes up to monitor downlink traffic.

[0103] In some example embodiments, synchronization time capability information may also be signaled by the terminal device 110 to the network device 120. The synchronization time capability information indicates a synchronization duration (also referred to as synchronization time) required by a transceiver (e.g.,) to synchronize after it wakes up. As mentioned above, such synchronization duration may be taken into account in determining a minimum time gap. The time required for synchronization may be appended to the minimum time gap value(s) reported by the terminal device 110. As alternative or in addition, the synchronization duration and the minimum time gap may be separately signalled to the network device.

[0104] FIG. 5 illustrates a signaling flow 500 for synchronization time capability reporting in accordance with some example embodiments of the present disclosure. For the purposes of discussion, the signaling flow 500 will be discussed with reference to FIG. 1. The signaling flow 500 may involve the terminal device 110 and the network device 120 in FIG. 1.

[0105] The network device 120 transmits (505), to the terminal device 110, configuration information associated with a DRX procedure for the terminal device 110.

[0106] The terminal device 110 receives (510) the configuration information associated with the DRX procedure from the network device 120 and determines (515) a synchronization duration of a transceiver based on the configuration information. This transceiver is configured to be woken up upon reception of a LP WUS from the network device 120, e.g., the main radio 114 of the terminal device 110 in FIG. IB. This transceiver is deactivated in a sleep mode and activated to monitor downlink traffic (e.g., PDCCH traffic) after the terminal device 110 (e.g., the WUR 112) detects a wake-up signal from the network device 120. The terminal device 110 transmits (520), to the network device 120, capability information indicating the synchronization duration of the transceiver.

[0107] The configuration information associated with the DRX procedure (e.g., cDRX configuration information) may be similar to those discussed with reference to FIG. 3. The configuration information may be transmitted to the terminal device 110 in a UE capability enquiry during the UE capability enquiry procedure. In some examples, the configuration information that the terminal device 110 uses to report or determine the synchronization time of the transceiver are provided as a part of the UE capability enquiry or as a part of cell or channel configuration.

[0108] In some example embodiments, the configuration information may indicate at least one of the following: a DRX cycle time, an on-duration timer value, or an inactivity timer value. In some example embodiments, the configuration information may further indicate a reference signal, RS, periodicity for the terminal device 110. The RS periodicity may include a periodicity for a synchronization signal block (SSB), a periodicity of a tracking reference signal (TRS), or a periodicity of other reference signal that may be used for synchronization.

[0109] The synchronization time required by the transceiver after it has been woken may at least partially depend on the network configuration of synchronization signals (e.g., the RS periodicity / periodicities), network configuration of connected mode discontinuous Reception (c-DRX) or LP-WUS (group or UE specific), or the like. Thus, by taking into account the DRX configuration indicated in the configuration information for the DRX procedure, the terminal device 110 may report back to the network device 120 the synchronization duration required by the transceiver.

[0110] In some example embodiments, the terminal device 110 may determine the synchronization duration required by the transceiver at least based on the RS periodicity configured for the terminal device 110. The synchronization duration required by the transceiver partially depends on the reference signal configured by the network device for synchronization. Thus, the network device 120 may provide the intended RS periodicity or periodicities to the terminal device 110 (e.g., in the configuration information carried in the UE capability enquiry or cell / channel configuration). The terminal device 110 may report back the synchronization duration(s) for the intended RS periodicity or periodicities. In some example embodiments, the network device 120 may provide a plurality of potential RS periodicities, and the terminal device 110 may determine and report different synchronization durations for the plurality of potential RS periodicities.

[0111] In some example embodiments, in addition to the DRX configuration, there may be other factors that may impact on the synchronization time required by the transceiver after it has been woken. Those factors may include, for example, LP-WUS receiver designs, device power consumption saving target, application latency target or the like. Any change in one or more of the factors above, may change the optimum (i.e. shortest / lowest latency) wake-up time that can be supported by both the network and device, and may thus also change the synchronization time of the transceiver. In some example embodiments, in addition to the DRX configuration, the terminal device 110 may also consider non-network information to determine the synchronization duration of the transceiver. Such information may include, for example, the power consumption or power level of the terminal device, the application level latency, proprietary hardware configuration options, the sleep mode(s) / power saving level(s) selected / supported by the terminal device. For example, the terminal device 110 under different circumstances, e.g., at different battery levels or different power consumption levels, may determine different synchronization durations.

[0112] The network device 120 receive (525), from the terminal device 110, capability information of the terminal device 110 indicating the synchronization duration of the transceiver of the terminal device 110, the transceiver being configured to be woken up upon the terminal device 110 receiving a LP WUS from the network device 120. The network device 120 performs (530) a communication with the terminal device 110 in the DRX procedure based on the capability information.

[0113] In some example embodiments, with the capability information about the synchronization duration of the transceiver of the terminal device 110, the network device 120 may update the configuration information associated with the DRX procedure for the terminal device 110. For example, the network device 120 may optimize the DRX configuration(s), e.g., adjust one or more of the DRX parameters, to maximise UE power savings using LP WUS or alternatively disable LP WUS. In some example embodiments, the network device 120 may modify a reference signal for synchronization of the transceiver, e.g., to increase or describe the RS periodicity configured for the terminal device 110.

[0114] In some example embodiments, if the network device 120 also receives the minimum time gap capability of the terminal device 110 (either in the same UE capability information with the synchronization time capability or reported separately from the synchronization time capability), the network device 120 may update the configuration information associated with the DRX procedure for the terminal device 110 based on both the reported minimum time gap(s) and synchronization duration. In some example embodiments, for each minimum time gap, the terminal device 110 may determine and report a corresponding synchronization duration required by the transceiver in the terminal device 110. The network device 120 may take the minimum time gap together with its associated synchronization duration into account when updating the configuration information for DRX.

[0115] In some example embodiments, if the LP-WUS operation is not possible, the terminal device may enable PDCCH monitoring in the on-duration configured for the DRX procedure as per legacy. The LP-WUS operation may be automatically resumed during the next “non-ONDuration” period that exceeds the minimum time gap reported by the terminal device.

[0116] Conventionally, it is assumed one wake-up time (corresponding to one minimum time gap) for the whole DRX session. In some example embodiments of the present disclosure, the terminal device 110 and the network device 120 may apply a plurality of minimum time gaps (LP-WUS wake-up times) for a DRX procedure (e.g., a cDRX procedure or a cDRX session in the connected mode of the terminal device 110), in order to improve UE power consumption. The terminal device 110 is allowed to dynamical switching between a plurality of minimum time gaps in different DRX cycles in the same DRX procedure (or the same DRX session).

[0117] FIG. 6 illustrates a signaling flow 600 for dynamic switching of LP-WUS wakeup times in accordance with some example embodiments of the present disclosure. For the purposes of discussion, the signaling flow 600 will be discussed with reference to FIG. I. The signaling flow 600 may involve the terminal device 110 and the network device 120 in FIG. 1.

[0118] In the signaling 600, the terminal device 110 obtains (605) a first minimum time gap between a first time period for monitoring a LP WUS and an on-duration for a first DRX cycle, and a second minimum time gap between a second time period for monitoring a LP WUS and an on-duration for a second DRX cycle. The second minimum time gap is different from the first minimum time gap. The first and second minimum time gaps may be selected from a plurality of minimum time gaps applicable for the terminal device 110. It would be appreciated that the terminal device 110 may apply more than two minimum time gaps, each may be determined for a particular DRX cycle during the DRX procedure.

[0119] The terminal device 110 monitors (610) the LP WUS from a network device 120 within the first time period before the first minimum time gap, and switch to the second minimum time gap. The terminal device 110 monitors (620) the LP WUS from the network device 120 within the second time period before the second minimum time gap.

[0120] With the minimum time gap determined, the terminal device 110 may determine a wake up signal time window (e.g., the first time period or the second time period) to monitor for LP WUS, in order to determine whether to wake up the transceiver (e.g., the MR) for PDCCH monitoring. The wake up signal time window may at least have a distance from the next on-duration in the next DRX cycle being lager than or equal to the minimum time gap, so that the transceiver is ready for PDCCH monitoring when a LP WUS is detected in the time window.

[0121] The first DRX cycle and the second DRX cycle may be the successive DRX cycles in the DRX procedure, or may be non-successive DRX cycles. For example, the terminal device 110 may apply the first minimum time gaps for more than one first DRX cycle and switch to the second minimum time gap for one or more second DRX cycles.

[0122] At the network side, the network device 120 also determines (606) the first minimum time gap between the first time period for a LP WUS and an on-duration for a first DRX cycle, and the second minimum time gap between a second time period for a LP WUS and an on-duration for the second DRX cycle for a network device 120. That is to say, the network device 120 and the terminal device 110 may be aligned with each other about the minimum time gaps for use in specific DRX cycles.

[0123] Then the network device 120 determines (612, 622) whether to transmit a LP WUS during the first time period and the second time period to the terminal device 110 based on the first minimum time gap and the second minimum time gap. For example, for a DRX cycle with less wake up time than the minim time gap, the network device 120 may decide not to transmit a LP WUS to wake up the terminal device 110 in that DRX cycle. In a case where the wake up time is greater than or equal to the corresponding minimum time gap, the network device 120 may transmit a LP WUS to wake up the terminal device 110 and perform data transmission in the on-duration of the DRX cycle.

[0124] In some example embodiments, the terminal device 110 may be configured by the network device 120 the plurality of minimum time gaps including the first minimum time gap and the second minimum time gap. In some example embodiments, the terminal device 110 may determine and report the plurality of minimum time gaps in its capability information to the network device 120, for example, in such a way as described with reference to FIG. 3. Specifically, the terminal device 110 may receive, from the network device 120, configuration information associated with a DRX procedure, indicating, for example, DRX cycle time, on-duration, inactivity timer, or the like. The terminal device 110 may then determine, based on the configuration information, the first minimum time gap for the first DRX cycle and the second minimum time gap for the second DRX cycle.

[0125] In some example embodiments, the terminal device 110 may receive, from the network device 120, the configuration information associated with a DRX procedure for the terminal device 110, and determine, based on the configuration information, at least one minimum time gap. Then the terminal device 110 may transmit, to the network device 120, capability information indicating the at least one minimum time gap. The network device 120 may determine at least one minimum time gap for the terminal device 110 based on the configuration information transmitted, or may receive, from the terminal device 110, capability information indicating the at least one minimum time gap.

[0126] In some example embodiments, if the configuration information comprises a plurality of DRX configurations (each DRX configuration may indicate a DRX cycle time, an on-duration timer value, or an inactivity timer value), the terminal device 110 may determine a same minimum time gap for the plurality of DRX configurations. In some example embodiments, the terminal device 110 may determine a plurality of minimum time gaps for the plurality of DRX configurations, respectively. In some example embodiments, the terminal device 110 may determine and report to the network device 120 an indication indicating no LP-WUS operation for a given DRX configuration among the plurality of DRX configurations, and wherein the capability information indicates the indication. From the capability information reported from the terminal device 110, or by determining based on the configuration information for the terminal device 110, the network device 120 may also determine whether the same or different minimum time gaps are determined for the plurality of DRX configurations. It is noted that each of the plurality of DRX configurations may be applied for one or more DRX cycles.

[0127] In some example embodiments, the terminal device 110 may determine, based on the configuration information, a first off-duration within the first DRX cycle and a second off-duration within the second DRX cycle. The off-duration (sometimes referred to effective off-duration) within a DRX cycle may be determined based on the DRX cycle time, the on-duration value, whether or not the inactivity timer is applied in the DRX cycle, and the inactivity timer value when the inactivity time is applied. The DRX configuration for different DRX cycles may be different, so different off-durations may be determined for the different DRX cycles.

[0128] In the specific example of FIG. 4, an off-duration within DRX cycle #n is from the end point of the inactivity period 412 corresponding to the inactivity timer to the start point of the next DRX cycle #n+l; and an off-duration within DRX cycle #n+l is from the end point of the on-duration 430 to the start point of the next DRX cycle as no inactivity timer is used in DRX cycle #n+l.

[0129] The terminal device 110 may determine the first minimum time gap for the first DRX cycle based on the first off-duration, and determine the second minimum time gap for the second DRX cycle based on the second off-duration. Similarly, the network device 120 may also determine the first and second minimum time gaps based on the configuration information to the terminal device 110.

[0130] The transition or switching between minimum time gaps among the DRX cycles may be determined based on one or more rules for gap selection shared by the network device 120 and the terminal device 110, without an explicit signaling from the terminal device 110 to the network device 120 or from the network device 120 to the terminal device 110. The rules for gap selection may be applied to select, from a plurality of candidate minimum time gaps, a minimum time gap for a DRX cycle based on the determined off-duration in the DRX cycle and one or more thresholds. In some examples, if an off-duration for a DRX cycle is larger than Threshold Value A but is smaller than Threshold Value B, then a minimum time gap “minGap Value 1” may be applied; if an off-duration for a DRX cycle is larger than Threshold Value A and also larger than Threshold Value B, then a minimum time gap “minGap Value 2” may be applied. If an off-duration for a DRX cycle is smaller than Threshold Value A but is larger than Threshold Value B, then the minimum time gap may be determined as zero, indicating that no LP-WUS transmission and the terminal device 110 may perform normal PDCCH monitoring.

[0131] In some examples, the switching between minimum time gaps among the DRX cycles may be completed within a DRX cycle to impact the next cDRX cycle. For example, the terminal device 110 may determine, within the first DRX cycle, to switch from the first minimum time gap to the second minimum time gap in the next second DRX cycle.

[0132] In some example embodiments, the transition or switching between minimum time gaps among the DRX cycles may be indicated with an explicit signalling. The terminal device 110 may receive, from the network device 120, an indication indicating a switching from the first minimum time gap in the first DRX cycle to the second minimum time gap in the second DRX cycle. As the switching is controlled by the network device 120, it may also determine which minimum time gap is applied in the certain DRX cycles for the terminal device 110. In some example embodiments, the indication for switching may be received by the terminal device 110 during the first DRX cycle. By receiving the indication for switching, the terminal device 110 may determine that the second minimum time gap is applied for the next DRX cycle.

[0133] In some example embodiments, the indication for minimum time gap switching may be signalled dynamically (e.g., within a DRX cycle, to impact the next DRX cycle) using Layer 1 / 2 transmissions, e.g., one or more DCI bits or MAC level headers. In some example embodiments, the indication for minimum time gap switching may be configured for the terminal device 110 in a semi-static manner, e.g., using a radio resource control, RRC, configuration. In some example embodiments, the indication from the network device 120 may include more than one candidate minimum time gap for the terminal device 110 to select for the next DRX cycle. In this case, the terminal device 110 may indicate a preference of minimum time gap in UL feedback to the network device.

[0134] In some example embodiments, the indication for minimum time gap switching may be configured for the terminal device 110 in a semi-static manner using UE assistance procedure.

[0135] The terminal device 110 may transmit, to the network device 120, preference information indicating at least one of the following: the first minimum time gap for the first DRX cycle, the second minimum time gap for the second DRX cycle, or a switching from the first minimum time gap in the first DRX cycle to the second minimum time gap in the second DRX cycle. The terminal device 110 may transmit, to the network device 120, the preference information in assistance information of the terminal device 110, during the UE assistance procedure. In this case, the network device 120 may determine, based on the preference information, the first minimum time gap for the first DRX cycle, the second minimum time gap for the second DRX cycle, or determine to switch from the first minimum time gap to the second minimum time gap.

[0136] In some example embodiments, the terminal device 110 may report to the network device a time gap configuration indicating at least one target minimum time gap selected from the plurality of minimum time gaps that are reported to the network device 120. By receiving such configuration, the network device 120 may determine which minimum time gap to be applied by the terminal device 110. This may be useful in helping the network to group UEs to use the same group LP-WUS signal.

[0137] In some example embodiments, if the LP-WUS operation is not possible, the terminal device may enable PDCCH monitoring in the on-duration configured for the DRX procedure as per legacy. The LP-WUS operation may be automatically resumed during the next “non-on-duration” period that exceeds the minimum time gap reported by the terminal device.

[0138] In some example embodiments, the terminal device 110 may provide synchronization time capability for each minimum gap time gap reported to the network device. The synchronization time capability indicates a synchronization duration required by a transceiver to resynchronize after it wakes up. In some example embodiments, the time required by the transceiver (e.g., the main radio 114) for re-synchronization may be appended to the minimum time gap value(s) the terminal device 110 reports or reported separately.

[0139] As described above with reference to FIG. 4, the parameters that the terminal device 110 uses to determine the synchronization duration(s) may be provided as a part of the UE capability enquiry (in the configuration information for DRX), or as a part of cell / channel configuration. In some example embodiments, the terminal device 110 determines the synchronization duration(s) at least based on the RS periodicity configured for the UE and / or provided in the UE capability enquiry. In some examples, the RS periodicity may be the SSB periodicity determined in the cell configuration, or the periodicity of tracking reference signals configured to the terminal device 110.

[0140] In some example embodiments, the network device 120 may provide the intended RS periodicity or periodicities in the configuration information for DRX (e.g., included in a UE capability enquiry). Then the terminal device 110 may report the synchronization duration(s) for the RS periodicities requested.

[0141] In one proposed embodiment, the terminal device 110 may report separate sets of minimum time gap values, and / or separate sets of synchronization durations for the transceiver according to the shared spectrum access mode.

[0142] FIG. 7A shows a flowchart of an example method 700 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 700 will be described from the perspective of the first apparatus. In some example embodiments, the first apparatus may be or may be comprised in the terminal device 110 in FIG. 1.

[0143] At block 710, the first apparatus receives, from a second apparatus, configuration information associated with a discontinuous reception, DRX, procedure for the first apparatus.

[0144] At block 720, the first apparatus determines, based on the configuration information, at least one minimum time gap each between a time period for monitoring a low-power wake-up signal, LP WUS, and an on-duration of the DRX procedure.

[0145] At block 730, the first apparatus transmits, to the second apparatus, capability information indicating the at least one minimum time gap.

[0146] In some example embodiments, the configuration information indicates at least one of the following: a DRX cycle time, an on-duration timer value, or an inactivity timer value.

[0147] In some example embodiments, the method 700 further comprises: receiving, from the second apparatus, the configuration information in a capability request or in a channel or cell configuration for the first apparatus.

[0148] In some example embodiments, the method 700 further comprises: determining, based on the configuration information, a minimum time gap between a time period for monitoring the LP WUS and an on-duration in a target DRX cycle; and transmitting, to the second apparatus, the capability information indicating the determined minimum time gap for the target DRX cycle.

[0149] In some example embodiments, the method 700 further comprises: receiving, from the second apparatus, a request to report minimum time gap capability for the target DRX cycle.

[0150] In some example embodiments, the method 700 further comprises: determining, based on the configuration information, at least one first minimum time gap applicable to a first target DRX cycle with a first DRX configuration and / or at least one second minimum time gap applicable to a second target DRX cycle with a second DRX configuration different from the first DRX configuration; and transmitting, to the second apparatus, the capability information indicating the at least one first minimum time gap and / or the at least one second minimum time gap.

[0151] In some example embodiments, the method 700 further comprises: receiving, from the second apparatus, a request to minimum time gap capability for the first target DRX cycle and the second target DRX cycle.

[0152] In some example embodiments, the method 700 further comprises: transmitting, to the second apparatus, the capability information indicating a minimum time gap corresponding to an ultra-deep sleep mode of the first apparatus and a minimum time gap corresponding to a sleep mode of the first apparatus.

[0153] In some example embodiments, the first apparatus is or is comprised in a terminal device. In some example embodiments, the second apparatus is or is comprised in a network device.

[0154] FIG. 7B shows a flowchart of an example method 702 implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 702 will be described from the perspective of the network device 120 in FIG. 1.

[0155] At block 750, the second apparatus transmits, to a first apparatus, configuration information associated with a discontinuous reception, DRX, procedure for the first apparatus.

[0156] At block 760, the second apparatus receives, from the first apparatus, capability information of the first apparatus indicating at least one minimum time gap each between a time period for monitoring a low-power wake-up signal, LP WUS, and an on-duration of the DRX procedure.

[0157] At block 770, the second apparatus performs a communication with the first apparatus in the DRX procedure based on the capability information.

[0158] In some example embodiments, the second apparatus is caused to perform, based on the capability information, at least one of the following: updating the configuration information associated with the DRX procedure for the first apparatus; transmitting a LP WUS to a group of apparatus comprising the first apparatus; or adjusting a data transmission in an on-duration of the DRX procedure.

[0159] In some example embodiments, the configuration information indicates at least one of the following: a DRX cycle time, an on-duration timer value, or an inactivity timer value.

[0160] In some example embodiments, the method 702 further comprises: transmitting, to the first apparatus, the configuration information in a capability request or in a channel or cell configuration for the first apparatus.

[0161] In some example embodiments, the method 702 further comprises: transmitting, to the first apparatus, a request to report minimum time gap capability for a target DRX cycle, receiving, from the first apparatus, the capability information indicating a determined minimum time gap for the target DRX cycle.

[0162] In some example embodiments, the method 702 further comprises: transmitting, to the first apparatus, a request to minimum time gap capability that is applicable up to a first target DRX cycle and / or below a second target DRX cycle; receiving, from the first apparatus, the capability information indicating at least one first minimum time gap applicable to a first target DRX cycle with a first DRX configuration and / or at least one second minimum time gap applicable to a second target DRX cycle with a second DRX configuration different from the first DRX configuration.

[0163] In some example embodiments, the method 702 further comprises: receiving, from the first apparatus, the capability information indicating a minimum time gap corresponding to an ultra-deep sleep mode of the first apparatus and a minimum time gap corresponding to a light sleep mode of the first apparatus.

[0164] In some example embodiments, the method 702 further comprises: receiving, from the first apparatus, the capability information indicating a plurality of separate sets of minimum time gaps according to a shared spectrum channel access mode.

[0165] In some example embodiments, a first apparatus capable of performing any of the method 700 (for example, the terminal device 110 in FIG. 1) may comprise means for performing the respective operations of the method 700. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the terminal device 110 in FIG. 1.

[0166] In some example embodiments, the first apparatus comprises means for receiving, from a second apparatus, configuration information associated with a discontinuous reception, DRX, procedure for the first apparatus; means for determining, based on the configuration information, at least one minimum time gap each between a time period for monitoring a low-power wake-up signal, LP WUS, and an on-duration of the DRX procedure; and means for transmitting, to the second apparatus, capability information indicating the at least one minimum time gap.

[0167] In some example embodiments, the configuration information indicates at least one of the following: a DRX cycle time, an on-duration timer value, or an inactivity timer value.

[0168] In some example embodiments, the first apparatus further comprises: means for receiving, from the second apparatus, the configuration information in a capability request or in a channel or cell configuration for the first apparatus.

[0169] In some example embodiments, the first apparatus further comprises: means for determining, based on the configuration information, a minimum time gap between a time period for monitoring the LP WUS and an on-duration in a target DRX cycle; and means for transmitting, to the second apparatus, the capability information indicating the determined minimum time gap for the target DRX cycle. [0170|In some example embodiments, the first apparatus further comprises: means for receiving, from the second apparatus, a request to report minimum time gap capability for the target DRX cycle.

[0171] In some example embodiments, the first apparatus further comprises: means for determining, based on the configuration information, at least one first minimum time gap applicable to a first target DRX cycle with a first DRX configuration and / or at least one second minimum time gap applicable to a second target DRX cycle with a second DRX configuration different from the first DRX configuration; and means for transmitting, to the second apparatus, the capability information indicating the at least one first minimum time gap and / or the at least one second minimum time gap.

[0172] In some example embodiments, the first apparatus further comprises: means for receiving, from the second apparatus, a request to minimum time gap capability for the first target DRX cycle and the second target DRX cycle.

[0173] In some example embodiments, the first apparatus further comprises: means for transmitting, to the second apparatus, the capability information indicating a minimum time gap corresponding to an ultra-deep sleep mode of the first apparatus and a minimum time gap corresponding to a sleep mode of the first apparatus.

[0174] In some example embodiments, the first apparatus is or is comprised in a terminal device, and wherein the second apparatus is or is comprised in a network device.

[0175] In some example embodiments, a second apparatus capable of performing any of the method 702 (for example, the network device 120 in FIG. 1) may comprise means for performing the respective operations of the method 702. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the network device 120 in FIG. 1.

[0176] In some example embodiments, the second apparatus comprises means for transmitting, to a first apparatus, configuration information associated with a discontinuous reception, DRX, procedure for the first apparatus; means for receiving, from the first apparatus, capability information of the first apparatus indicating at least one minimum time gap each between a time period for monitoring a low-power wake-up signal, LP WUS, and an on-duration of the DRX procedure; and means for performing a communication with the first apparatus in the DRX procedure based on the capability information.

[0177] In some example embodiments, the second apparatus is caused to perform, based on the capability information, at least one of the following: updating the configuration information associated with the DRX procedure for the first apparatus; transmitting a LP WUS to a group of apparatus comprising the first apparatus; or adjusting a data transmission in an on-duration of the DRX procedure.

[0178] In some example embodiments, the configuration information indicates at least one of the following: a DRX cycle time, an on-duration timer value, or an inactivity timer value.

[0179] In some example embodiments, the second apparatus further comprises: means for transmitting, to the first apparatus, the configuration information in a capability request or in a channel or cell configuration for the first apparatus.

[0180] In some example embodiments, the second apparatus further comprises: means for transmitting, to the first apparatus, a request to report minimum time gap capability for a target DRX cycle; means for receiving, from the first apparatus, the capability information indicating a determined minimum time gap for the target DRX cycle.

[0181] In some example embodiments, the second apparatus further comprises: means for transmitting, to the first apparatus, a request to minimum time gap capability that is applicable up to a first target DRX cycle and / or below a second target DRX cycle; means for receiving, from the first apparatus, the capability information indicating at least one first minimum time gap applicable to a first target DRX cycle with a first DRX configuration and / or at least one second minimum time gap applicable to a second target DRX cycle with a second DRX configuration different from the first DRX configuration.

[0182] In some example embodiments, the second apparatus further comprises: means for receiving, from the first apparatus, the capability information indicating a minimum time gap corresponding to an ultra-deep sleep mode of the first apparatus and a minimum time gap corresponding to a light sleep mode of the first apparatus.

[0183] In some example embodiments, the second apparatus further comprises: means for receiving, from the first apparatus, the capability information indicating a plurality of separate sets of minimum time gaps according to a shared spectrum channel access mode.

[0184] FIG. 8A shows a flowchart of an example method 800 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 800 will be described from the perspective of the terminal device 110 in FIG. 1.

[0185] At block 810, the first apparatus receives, from a second apparatus, configuration information associated with a discontinuous reception, DRX, procedure for the first apparatus.

[0186] At block 820, the first apparatus determines, based on the configuration information, a synchronization duration of a transceiver, the transceiver being configured to be woken up upon reception of a low-power wake-up signal, LP WUS, from the second apparatus.

[0187] At block 830, the first apparatus transmits, to the second apparatus, capability information indicating the synchronization duration of the transceiver.

[0188] In some example embodiments, the configuration information indicates at least one of the following: a DRX cycle time, an on-duration timer value, an inactivity timer value, or a reference signal, RS, periodicity for the first apparatus.

[0189] In some example embodiments, the RS periodicity comprises a periodicity for a synchronization signal block, SSB, or a periodicity of a tracking reference signal.

[0190] In some example embodiments, the method 800 further comprises: receiving, from the second apparatus, the configuration information in a capability request or in a channel or cell configuration for the first apparatus.

[0191] In some example embodiments, the method 800 further comprises: transmitting, to the second apparatus, capability information indicating the synchronization duration of the transceiver and at least one minimum time gap each between a time period for monitoring the LP WUS and an on-duration of the DRX procedure.

[0192] In some example embodiments, the first apparatus is or is comprised in a terminal device. In some example embodiments, the second apparatus is or is comprised in a network device.

[0193] FIG. 8B shows a flowchart of an example method 802 implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 802 will be described from the perspective of the network device 120 in FIG. 1.

[0194] At block 850, the second apparatus transmits, to a first apparatus, configuration information associated with a discontinuous reception, DRX, procedure for the first apparatus.

[0195] At block 860, the second apparatus receives, from the first apparatus, capability information of the first apparatus indicating a synchronization duration of a transceiver of the first apparatus, the transceiver being configured to be woken up upon the first apparatus receiving a low-power wake-up signal, LP WUS, from the second apparatus.

[0196] At block 870, the second apparatus performs a communication with the first apparatus in the DRX procedure based on the capability information.

[0197] In some example embodiments, the method 802 further comprises performing, based on the capability information, at least one of the following: updating the configuration information associated with the DRX procedure for the first apparatus; modifying a reference signal for synchronization of the transceiver.

[0198] In some example embodiments, the configuration information indicates at least one of the following: a DRX cycle time, an on-duration timer value, an inactivity timer value, or a reference signal, RS, periodicity for the first apparatus.

[0199] In some example embodiments, the RS periodicity comprises a periodicity for a synchronization signal block, SSB, or a periodicity of a tracking reference signal.

[0200] In some example embodiments, the method 802 further comprises: transmitting, to the first apparatus, the configuration information in a capability request or in a channel or cell configuration for the first apparatus.

[0201] In some example embodiments, the method 802 further comprises: receiving, from the first apparatus, capability information indicating the synchronization duration of the transceiver and a minimum time gap between a time period for monitoring the LP WUS and an on-duration of the DRX procedure.

[0202] In some example embodiments, the first apparatus is or is comprised in a terminal device. In some example embodiments, the second apparatus is or is comprised in a network device.

[0203] In some example embodiments, a first apparatus capable of performing any of the method 800 (for example, the terminal device 110 in FIG. 1) may comprise means for performing the respective operations of the method 800. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the terminal device 110 in FIG. 1.

[0204] In some example embodiments, the first apparatus comprises means for receiving, from a second apparatus, configuration information associated with a discontinuous reception, DRX, procedure for the first apparatus; means for determining, based on the configuration information, a synchronization duration of a transceiver, the transceiver being configured to be woken up upon reception of a low-power wake-up signal, LP WUS, from the second apparatus; and means for transmitting, to the second apparatus, capability information indicating the synchronization duration of the transceiver.

[0205] In some example embodiments, the configuration information indicates at least one of the following: a DRX cycle time, an on-duration timer value, an inactivity timer value, or a reference signal, RS, periodicity for the first apparatus. |0206|In some example embodiments, the RS periodicity comprises a periodicity for a synchronization signal block, SSB, or a periodicity of a tracking reference signal.

[0207] In some example embodiments, the first apparatus further comprises: means for receiving, from the second apparatus, the configuration information in a capability request or in a channel or cell configuration for the first apparatus.

[0208] In some example embodiments, the first apparatus further comprises: means for transmitting, to the second apparatus, capability information indicating the synchronization duration of the transceiver and at least one minimum time gap each between a time period for monitoring the LP WUS and an on-duration of the DRX procedure.

[0209] In some example embodiments, the first apparatus is or is comprised in a terminal device, and wherein the second apparatus is or is comprised in a network device.

[0210] In some example embodiments, a second apparatus capable of performing any of the method 802 (for example, the network device 120 in FIG. 1) may comprise means for performing the respective operations of the method 802. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the network device 120 in FIG. 1.

[0211] In some example embodiments, the second apparatus comprises means for transmitting, to a first apparatus, configuration information associated with a discontinuous reception, DRX, procedure for the first apparatus; means for receiving, from the first apparatus, capability information of the first apparatus indicating a synchronization duration of a transceiver of the first apparatus, the transceiver being configured to be woken up upon the first apparatus receiving a low-power wake-up signal, LP WUS, from the second apparatus; and means for performing a communication with the first apparatus in the DRX procedure based on the capability information.

[0212] In some example embodiments, the second apparatus further comprises means for performing, based on the capability information, at least one of the following: updating the configuration information associated with the DRX procedure for the first apparatus; modifying a reference signal for synchronization of the transceiver.

[0213] In some example embodiments, the configuration information indicates at least one of the following: a DRX cycle time, an on-duration timer value, an inactivity timer value, or a reference signal, RS, periodicity for the first apparatus.

[0214] In some example embodiments, the RS periodicity comprises a periodicity for a synchronization signal block, SSB, or a periodicity of a tracking reference signal.

[0215] In some example embodiments, the second apparatus further comprises: means for transmitting, to the first apparatus, the configuration information in a capability request or in a channel or cell configuration for the first apparatus.

[0216] In some example embodiments, the second apparatus further comprises: means for receiving, from the first apparatus, capability information indicating the synchronization duration of the transceiver and a minimum time gap between a time period for monitoring the LP WUS and an on-duration of the DRX procedure.

[0217] In some example embodiments, the first apparatus is or is comprised in a terminal device. In some example embodiments, the second apparatus is or is comprised in a network device.

[0218] FIG. 9A shows a flowchart of an example method 900 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 900 will be described from the perspective of the terminal device 110 in FIG. 1.

[0219] At block 910, the first apparatus obtains a first minimum time gap between a first time period for monitoring a low-power wake-up signal, LP WUS, and an on-duration for a first discontinuous reception, DRX, cycle, and a second minimum time gap between a second time period for monitoring a LP WUS and an on-duration for a second DRX cycle, the second minimum time gap being different from the first minimum time gap.

[0220] At block 920, the first apparatus monitors the LP WUS from a second apparatus within the first time period before the first minimum time gap.

[0221] At block 930, the first apparatus monitors the LP WUS from the second apparatus within the second time period before the second minimum time gap.

[0222] In some example embodiments, the method 900 further comprises: receiving, from the second apparatus, configuration information associated with a DRX procedure for the first apparatus; and determining, based on the configuration information, the first minimum time gap for the first DRX cycle and the second minimum time gap for the second DRX cycle.

[0223] In some example embodiments, the method 900 further comprises: determining, based on the configuration information, a first off-duration within the first DRX cycle and a second off-duration within the second DRX cycle; determining the first minimum time gap for the first DRX cycle based on the first off-duration; and determining the second minimum time gap for the second DRX cycle based on the second off-duration.

[0224] In some example embodiments, the method 900 further comprises: receiving, from the second apparatus, an indication indicating a switching from the first minimum time gap in the first DRX cycle to the second minimum time gap in the second DRX cycle.

[0225] In some example embodiments, the indication is received during the first DRX cycle.

[0226] In some example embodiments, the method 900 further comprises: receiving, from the second apparatus, the indication in a radio resource control, RRC, configuration.

[0227] In some example embodiments, the method 900 further comprises: transmitting, to the second apparatus, preference information indicating at least one of the following: the first minimum time gap for the first DRX cycle, the second minimum time gap for the second DRX cycle, or a switching from the first minimum time gap in the first DRX cycle to the second minimum time gap in the second DRX cycle.

[0228] In some example embodiments, the method 900 further comprises: transmitting, to the second apparatus, the preference information in assistance information of the first apparatus.

[0229] In some example embodiments, the method 900 further comprises: receiving, from the second apparatus, configuration information associated with a DRX procedure for the first apparatus; determining, based on the configuration information, at least one minimum time gap; and transmitting, to the second apparatus, capability information indicating the at least one minimum time gap.

[0230] In some example embodiments, the method 900 further comprises: determine a same minimum time gap for the plurality of DRX configurations; determine a plurality of minimum time gaps for the plurality of DRX configurations, respectively; or determine an indication indicating no LP-WUS operation for a given DRX configuration among the plurality of DRX configurations. In some example embodiments, the capability information indicates the indication.

[0231] In some example embodiments, the method 900 further comprises: receiving, from the second apparatus, time gap configuration indicating at least one target minimum time gap, a target minimum time gap being selected from the plurality of minimum time gaps reported to the second apparatus. In some example embodiments, at least one of the first and second minimum time gaps is selected from the at least one target minimum time gap-

[0232] In some example embodiments, the first apparatus is or is comprised in a terminal device. In some example embodiments, the second apparatus is or is comprised in a network device.

[0233] FIG. 9B shows a flowchart of an example method 902 implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 902 will be described from the perspective of the network device 120 in FIG. 1.

[0234] At block 950, the second apparatus determines a first minimum time gap between a first time period for a low-power wake-up signal, LP WUS, and an on-duration for a first discontinuous reception, DRX, cycle, and a second minimum time gap between a second time period for a LP WUS and an on-duration for a second DRX cycle for a second apparatus, the second minimum time gap being different from the first minimum time gap.

[0235] At block 960, the second apparatus determines whether to transmit a LP WUS during the first time period and the second time period to the first apparatus based on the first minimum time gap and the second minimum time gap.

[0236] In some example embodiments, the method 902 further comprises: transmitting, to the first apparatus, configuration information associated with a DRX procedure for the first apparatus, and determining, based on the configuration information, the first minimum time gap for the first DRX cycle and the second minimum time gap for the second DRX cycle.

[0237] In some example embodiments, the method 902 further comprises: determining, based on the configuration information, a first off-duration within the first DRX cycle and a second off-duration within the second DRX cycle; determining the first minimum time gap for the first DRX cycle based on the first off-duration; and determining the second minimum time gap for the second DRX cycle based on the second off-duration.

[0238] In some example embodiments, the method 902 further comprises: transmitting, to the first apparatus, an indication indicating a switching from the first minimum time gap in the first DRX cycle to the second minimum time gap in the second DRX cycle.

[0239] In some example embodiments, the indication is transmitted during the first DRX cycle.

[0240] In some example embodiments, the method 902 further comprises: transmitting, to the first apparatus, the indication in a radio resource control, RRC, configuration.

[0241] In some example embodiments, the method 902 further comprises: receiving, from the first apparatus, preference information indicating at least one of the following: the first minimum time gap for the first DRX cycle, the second minimum time gap for the second DRX cycle, or a switching from the first minimum time gap in the first DRX cycle to the second minimum time gap in the second DRX cycle; and determining, based on the preference information, the first minimum time gap for the first DRX cycle and the second minimum time gap for the second DRX cycle.

[0242] In some example embodiments, the method 902 further comprises: receiving, from the first apparatus, the preference information in assistance information of the first apparatus.

[0243] In some example embodiments, the method 902 further comprises: transmitting, to the first apparatus, configuration information associated with a DRX procedure for the first apparatus; and receiving, from the first apparatus, capability information indicating the at least one minimum time gap.

[0244] In some example embodiments, the method 902 further comprises: receive, from the first apparatus, capability information indicating: a same minimum time gap for the plurality of DRX configurations; a plurality of minimum time gaps for the plurality of DRX configurations, respectively; or an indication indicating no LP-WUS operation for a given DRX configuration among the plurality of DRX configurations, and wherein the capability information indicates the indication.

[0245] In some example embodiments, the method 902 further comprises: transmitting, to the first apparatus, time gap configuration indicating at least one target minimum time gap, a target minimum time gap being between the plurality of minimum time gaps reported to the second apparatus; and wherein at least one of the first and second minimum time gaps is selected from the at least one target minimum time gap.

[0246] In some example embodiments, a first apparatus capable of performing any of the method 900 (for example, the terminal device 110 in FIG. 1) may comprise means for performing the respective operations of the method 900. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the terminal device 110 in FIG. 1.

[0247] In some example embodiments, the first apparatus comprises means for obtaining a first minimum time gap between a first time period for monitoring a low-power wake-up signal, LP WUS, and an on-duration for a first discontinuous reception, DRX, cycle, and a second minimum time gap between a second time period for monitoring a LP WUS and an on-duration for a second DRX cycle, the second minimum time gap being different from the first minimum time gap; means for monitoring the LP WUS from a second apparatus within the first time period before the first minimum time gap; and means for monitoring the LP WUS from the second apparatus within the second time period before the second minimum time gap.

[0248] In some example embodiments, the first apparatus further comprises: means for receiving, from the second apparatus, configuration information associated with a DRX procedure for the first apparatus; and means for determining, based on the configuration information, the first minimum time gap for the first DRX cycle and the second minimum time gap for the second DRX cycle.

[0249] In some example embodiments, the first apparatus further comprises: means for determining, based on the configuration information, a first off-duration within the first DRX cycle and a second off-duration within the second DRX cycle; means for determining the first minimum time gap for the first DRX cycle based on the first off-duration; and means for determining the second minimum time gap for the second DRX cycle based on the second off-duration.

[0250] In some example embodiments, the first apparatus further comprises: means for receiving, from the second apparatus, an indication indicating a switching from the first minimum time gap in the first DRX cycle to the second minimum time gap in the second DRX cycle. [0251 ]In some example embodiments, the indication is received during the first DRX cycle.

[0252] In some example embodiments, the first apparatus further comprises: means for receiving, from the second apparatus, the indication in a radio resource control, RRC, configuration.

[0253] In some example embodiments, the first apparatus further comprises: means for transmitting, to the second apparatus, preference information indicating at least one of the following: means for the first minimum time gap for the first DRX cycle, means for the second minimum time gap for the second DRX cycle, or means for a switching from the first minimum time gap in the first DRX cycle to the second minimum time gap in the second DRX cycle.

[0254] In some example embodiments, the first apparatus further comprises: means for transmitting, to the second apparatus, the preference information in assistance information of the first apparatus.

[0255] In some example embodiments, the first apparatus further comprises: means for receiving, from the second apparatus, configuration information associated with a DRX procedure for the first apparatus; means for determining, based on the configuration information, at least one minimum time gap; and means for transmitting, to the second apparatus, capability information indicating the at least one minimum time gap.

[0256] In some example embodiments, the first apparatus further comprises: determine a same minimum time gap for the plurality of DRX configurations; determine a plurality of minimum time gaps for the plurality of DRX configurations, respectively; or determine an indication indicating no LP-WUS operation for a given DRX configuration among the plurality of DRX configurations, and wherein the capability information indicates the indication.

[0257] In some example embodiments, the first apparatus further comprises: means for receiving, from the second apparatus, time gap configuration indicating at least one target minimum time gap, a target minimum time gap being selected from the plurality of minimum time gaps reported to the second apparatus; and wherein at least one of the first and second minimum time gaps is selected from the at least one target minimum time gap.

[0258] In some example embodiments, a second apparatus capable of performing any of the method 902 (for example, the network device 120 in FIG. 1) may comprise means for performing the respective operations of the method 902. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the network device 120 in FIG. 1.

[0259] In some example embodiments, the second apparatus comprises means for determining a first minimum time gap between a first time period for a low-power wakeup signal, LP WUS, and an on-duration for a first discontinuous reception, DRX, cycle, and a second minimum time gap between a second time period for a LP WUS and an on-duration for a second DRX cycle for a second apparatus, the second minimum time gap being different from the first minimum time gap; and means for determining whether to transmit a LP WUS during the first time period and the second time period to the first apparatus based on the first minimum time gap and the second minimum time gap.

[0260] In some example embodiments, the second apparatus further comprises: means for transmitting, to the first apparatus, configuration information associated with a DRX procedure for the first apparatus; and means for determining, based on the configuration information, the first minimum time gap for the first DRX cycle and the second minimum time gap for the second DRX cycle.

[0261] In some example embodiments, the second apparatus further comprises: means for determining, based on the configuration information, a first off-duration within the first DRX cycle and a second off-duration within the second DRX cycle; means for determining the first minimum time gap for the first DRX cycle based on the first off-duration; and means for determining the second minimum time gap for the second DRX cycle based on the second off-duration.

[0262] In some example embodiments, the second apparatus further comprises: means for transmitting, to the first apparatus, an indication indicating a switching from the first minimum time gap in the first DRX cycle to the second minimum time gap in the second DRX cycle.

[0263] In some example embodiments, the indication is transmitted during the first DRX cycle.

[0264] In some example embodiments, the second apparatus further comprises: means for transmitting, to the first apparatus, the indication in a radio resource control, RRC, configuration.

[0265] In some example embodiments, the second apparatus further comprises: means for receiving, from the first apparatus, preference information indicating at least one of the following: means for the first minimum time gap for the first DRX cycle, means for the second minimum time gap for the second DRX cycle, or means for a switching from the first minimum time gap in the first DRX cycle to the second minimum time gap in the second DRX cycle; and means for determining, based on the preference information, the first minimum time gap for the first DRX cycle and the second minimum time gap for the second DRX cycle.

[0266] In some example embodiments, the second apparatus further comprises: means for receiving, from the first apparatus, the preference information in assistance information of the first apparatus.

[0267] In some example embodiments, the second apparatus further comprises: means for transmitting, to the first apparatus, configuration information associated with a DRX procedure for the first apparatus; and means for receiving, from the first apparatus, capability information indicating the at least one minimum time gap.

[0268] In some example embodiments, the second apparatus further comprises: receive, from the first apparatus, capability information indicating: a same minimum time gap for the plurality of DRX configurations; a plurality of minimum time gaps for the plurality of DRX configurations, respectively; or an indication indicating no LP-WUS operation for a given DRX configuration among the plurality of DRX configurations, and wherein the capability information indicates the indication.

[0269] In some example embodiments, the second apparatus further comprises: means for transmitting, to the first apparatus, time gap configuration indicating at least one target minimum time gap, a target minimum time gap being between the plurality of minimum time gaps reported to the second apparatus; and wherein at least one of the first and second minimum time gaps is selected from the at least one target minimum time gap.

[0270] FIG. 10 is a simplified block diagram of a device 1000 that is suitable for implementing example embodiments of the present disclosure. The device 1000 may be provided to implement a communication device, for example, the terminal device 110 or the network device 120 as shown in FIG. 1. As shown, the device 1000 includes one or more processors 1010, one or more memories 1020 coupled to the processor 1010, and one or more communication modules 1040 coupled to the processor 1010.

[0271] The communication module 1040 is for bidirectional communications. The communication module 1040 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interfaces may represent any interface that is necessary for communication with other network elements. In some example embodiments, the communication module 1040 may include at least one antenna.

[0272] The processor 1010 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 1000 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

[0273] The memory 1020 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 1024, an electrically programmable read only memory (EPROM), a flash memory, a hard disk, a compact disc (CD), a digital video disk (DVD), an optical disk, a laser disk, and other magnetic storage and / or optical storage. Examples of the volatile memories include, but are not limited to, a random-access memory (RAM) 1022 and other volatile memories that will not last in the power-down duration.

[0274] A computer program 1030 includes computer executable instructions that are executed by the associated processor 1010. The instructions of the program 1030 may include instructions for performing operations / acts of some example embodiments of the present disclosure. The program 1030 may be stored in the memory, e.g., the ROM 1024. The processor 1010 may perform any suitable actions and processing by loading the program 1030 into the RAM 1022.

[0275] The example embodiments of the present disclosure may be implemented by means of the program 1030 so that the device 1000 may perform any process of the disclosure as discussed with reference to FIG. 3 to FIG. 9B. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0276] In some example embodiments, the program 1030 may be tangibly contained in a computer readable medium which may be included in the device 1000 (such as in the memory 1020) or other storage devices that are accessible by the device 1000. The device 1000 may load the program 1030 from the computer readable medium to the RAM 1022 for execution. In some example embodiments, the computer readable medium may include any types of non-transitory storage medium, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0277] FIG. 11 shows an example of the computer readable medium 1100 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 1100 has the program 1030 stored thereon.

[0278] Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, and other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. Although various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0279] Some example embodiments of the present disclosure also provide at least one computer program product tangibly stored on a computer readable medium, such as a non-transitory computer readable medium. The computer program product includes computerexecutable instructions, such as those included in program modules, being executed in a device on a target physical or virtual processor, to carry out any of the methods as described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

[0280] Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. The program code may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program code, when executed by the processor or controller, cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

[0281] In the context of the present disclosure, the computer program code or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

[0282] The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0283] Further, although operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, although several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Unless explicitly stated, certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated, various features that are described in the context of a single embodiment may also be implemented in a plurality of embodiments separately 5 or in any suitable sub-combination.

[0284] Although the present disclosure has been described in languages specific to structural features and / or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are 10 disclosed as example forms of implementing the claims.

Claims

1. A first apparatus comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to:obtain a first minimum time gap between a first time period for monitoring a low-power wake-up signal, LP WUS, and an on-duration for a first discontinuous reception, DRX, cycle, and a second minimum time gap between a second time period for monitoring a LP WUS and an on-duration for a second DRX cycle, the second minimum time gap being different from the first minimum time gap;monitor the LP WUS from a second apparatus within the first time period before the first minimum time gap; andmonitor the LP WUS from the second apparatus within the second time period before the second minimum time gap.

2. The first apparatus of claim 1, wherein the first apparatus is further caused to:receive, from the second apparatus, configuration information associated with a DRX procedure for the first apparatus; anddetermine, based on the configuration information, the first minimum time gap for the first DRX cycle and the second minimum time gap for the second DRX cycle.

3. The first apparatus of claim 2, wherein the first apparatus is further caused to:determine, based on the configuration information, a first off-duration within the first DRX cycle and a second off-duration within the second DRX cycle;determine the first minimum time gap for the first DRX cycle based on the first off-duration; anddetermine the second minimum time gap for the second DRX cycle based on the second off-duration.

4. The first apparatus of claim 1, wherein the first apparatus is further caused to:receive, from the second apparatus, an indication indicating a switching from the first minimum time gap in the first DRX cycle to the second minimum time gap in the second DRXcycle.

5. The first apparatus of claim 4, wherein the indication is received during the first DRX cycle.

6. The first apparatus of claim 4 or 5, wherein the first apparatus is further caused to:receive, from the second apparatus, the indication in a radio resource control, RRC, configuration.

7. The first apparatus of claim 1, wherein the first apparatus is further caused to:transmit, to the second apparatus, preference information indicating at least one of the following:the first minimum time gap for the first DRX cycle,the second minimum time gap for the second DRX cycle, ora switching from the first minimum time gap in the first DRX cycle to the second minimum time gap in the second DRX cycle.

8. The first apparatus of claim 7, wherein the first apparatus is further caused to: transmit, to the second apparatus, the preference information in assistance information of the first apparatus.

9. The first apparatus of any of claims 1 to 8, wherein the first apparatus is caused to:receive, from the second apparatus, configuration information associated with a DRX procedure for the first apparatus;determine, based on the configuration information, at least one minimum time gap; and transmit, to the second apparatus, capability information indicating the at least one minimum time gap.

10. The first apparatus of claim 9, wherein the configuration information comprises a plurality of DRX configurations, and a DRX configuration at least one of the following: a DRX cycle time, an on-duration timer value, or an inactivity timer value; andwherein the first apparatus is caused to:determine a same minimum time gap for the plurality of DRX configurations;determine a plurality of minimum time gaps for the plurality of DRXconfigurations, respectively; ordetermine an indication indicating no LP-WUS operation for a given DRX configuration among the plurality of DRX configurations, and wherein the capability information indicates the indication.

11. The first apparatus of claim 10, wherein the first apparatus is further caused to:receive, from the second apparatus, time gap configuration indicating at least one target minimum time gap, a target minimum time gap being selected from the plurality of minimum time gaps reported to the second apparatus; andwherein at least one of the first and second minimum time gaps is selected from the at least one target minimum time gap.

12. A second apparatus comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus at least to:determine a first minimum time gap between a first time period for a low-power wake-up signal, LP WUS, and an on-duration for a first discontinuous reception, DRX, cycle, and a second minimum time gap between a second time period for a LP WUS and an on-duration for a second DRX cycle for a second apparatus, the second minimum time gap being different from the first minimum time gap; anddetermine whether to transmit a LP WUS during the first time period and the second time period to the first apparatus based on the first minimum time gap and the second minimum time gap.

13. The second apparatus of claim 12, wherein the second apparatus is further caused to:transmit, to the first apparatus, configuration information associated with a DRX procedure for the first apparatus; anddetermine, based on the configuration information, the first minimum time gap for the first DRX cycle and the second minimum time gap for the second DRX cycle.

14. The second apparatus of claim 13, wherein the second apparatus is further caused to:determine, based on the configuration information, a first off-duration within the first DRX cycle and a second off-duration within the second DRX cycle;determine the first minimum time gap for the first DRX cycle based on the first off-duration; anddetermine the second minimum time gap for the second DRX cycle based on the second off-duration.

15. The second apparatus of claim 12, wherein the second apparatus is further caused to:transmit, to the first apparatus, an indication indicating a switching from the first minimum time gap in the first DRX cycle to the second minimum time gap in the second DRX cycle.

16. The second apparatus of claim 12, wherein the second apparatus is further caused to:receive, from the first apparatus, preference information indicating at least one of the following:the first minimum time gap for the first DRX cycle,the second minimum time gap for the second DRX cycle, ora switching from the first minimum time gap in the first DRX cycle to the second minimum time gap in the second DRX cycle; anddetermine, based on the preference information, the first minimum time gap for the first DRX cycle and the second minimum time gap for the second DRX cycle.

17. The second apparatus of claim 16, wherein the second apparatus is further caused to:receive, from the first apparatus, the preference information in assistance information of the first apparatus.

18. The second apparatus of any of claims 12 to 17, wherein the second apparatus is caused to:transmit, to the first apparatus, configuration information associated with a DRX procedure for the first apparatus; andreceive, from the first apparatus, capability information indicating the at least oneminimum time gap.

19. The second apparatus of claim 18, wherein the configuration information comprises a plurality of DRX configurations, and a DRX configuration at least one of the following: a DRX cycle time, an on-duration timer value, or an inactivity timer value; andwherein the second apparatus is caused to: receive, from the first apparatus, capability information indicating:a same minimum time gap for the plurality of DRX configurations;a plurality of minimum time gaps for the plurality of DRX configurations, respectively; oran indication indicating no LP-WUS operation for a given DRX configuration among the plurality of DRX configurations, and wherein the capability information indicates the indication.

20. The second apparatus of any of claims 12 to 19, wherein the second apparatus is further caused to:transmit, to the first apparatus, time gap configuration indicating at least one target minimum time gap, a target minimum time gap being between the plurality of minimum time gaps reported to the second apparatus; andwherein at least one of the first and second minimum time gaps is selected from the at least one target minimum time gap.

21. A method comprising:obtaining, by a first apparatus, a first minimum time gap between a first time period for monitoring a low-power wake-up signal, LP WUS, and an on-duration for a first discontinuous reception, DRX, cycle, and a second minimum time gap between a second time period for monitoring a LP WUS and an on-duration for a second DRX cycle, the second minimum time gap being different from the first minimum time gap.monitoring the LP WUS from a second apparatus within the first time period before the first minimum time gap.monitoring the LP WUS from the second apparatus within the second time period before the second minimum time gap.

22. A method comprising:determining, by a second apparatus, a first minimum time gap between a first time period for a low-power wake-up signal, LP WUS, and an on-duration for a first discontinuous reception, DRX, cycle, and a second minimum time gap between a second time period for a LP WUS and an on-duration for a second DRX cycle for a second apparatus, the second minimum time gap being different from the first minimum time gap.determining whether to transmit a LP WUS during the first time period and the second time period to the first apparatus based on the first minimum time gap and the second minimum time gap.

23. A first apparatus comprising:means for obtaining a first minimum time gap between a first time period for monitoring a low-power wake-up signal, LP WUS, and an on-duration for a first discontinuous reception, DRX, cycle, and a second minimum time gap between a second time period for monitoring a LP WUS and an on-duration for a second DRX cycle, the second minimum time gap being different from the first minimum time gap;means for monitoring the LP WUS from a second apparatus within the first time period before the first minimum time gap; andmeans for monitoring the LP WUS from the second apparatus within the second time period before the second minimum time gap.

24. A second apparatus comprising:means for determining a first minimum time gap between a first time period for a low-power wake-up signal, LP WUS, and an on-duration for a first discontinuous reception, DRX, cycle, and a second minimum time gap between a second time period for a LP WUS and an on-duration for a second DRX cycle for a second apparatus, the second minimum time gap being different from the first minimum time gap; andmeans for determining whether to transmit a LP WUS during the first time period and the second time period to the first apparatus based on the first minimum time gap and the second minimum time gap.

25. A computer readable medium comprising instructions stored thereon for causing an apparatus at least to perform the method of claim 21 or the method of claim 22.

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