Cell reselection with priority rule selection

Abstract

Embodiments of the present disclosure relate to devices, methods, apparatuses, and computer readable storage media for cell reselection with priority rule selection. In a method, a first apparatus obtains a configuration of a cell reselection indicating at least one condition for selecting a priority rule for the cell reselection. The at least one condition is based on at least one of: at least one cell quality threshold associated with a low power wake up signal (LP-WUS), a mobility state of the first apparatus, or capability for supporting LP-WUS of at least one frequency layer. If the at least one condition is satisfied, the first apparatus performs the cell reselection based on a first priority rule. The first priority rule prioritizes a first candidate cell corresponding to a first frequency layer supporting the LP-WUS over a second candidate cell corresponding to a second frequency layer.

Description

CELL RESELECTION WITH PRIORITY RULE SELECTIONCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority from, and the benefit of, US Provisional Application No. 63 / 702971 , filed Oct. 3, 2024, which is hereby incorporated by reference in its entirety.FIELDS

[0002] Various example embodiments of the present disclosure generally relate to the field of telecommunication, and in particular, to methods, devices, apparatuses and computer readable storage medium for cell reselection with priority rule selection.BACKGROUND

[0003] Fifth Generation (5G) systems are designed and developed targeting for both mobile telephony and vertical use cases. Besides latency, reliability, and availability, user equipment (UE) energy efficiency is also critical to 5G. Currently, 5G devices may have to be recharged per week or day, depending on individual’s usage time. In general, 5G devices consume tens of milliwatts in radio resource control (RRC) idle / inactive state and hundreds of milliwatts in RRC connected state. Designs to prolong battery life is a necessity for improving energy efficiency as well as for better user experience.

[0004] Energy efficiency is even more critical for UEs without a continuous energy source, e.g., UEs using small rechargeable and single coin cell batteries. Among vertical use cases, sensors and actuators are deployed extensively for monitoring, measuring, charging, etc. Generally, their batteries are not rechargeable and expected to last at least few years. Works are ongoing regarding UE supporting a low power mode.SUMMARY

[0005] 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 to: obtain a configuration of a cell reselection, the configuration indicating at least one condition for selecting a priority rule for the cell reselection, wherein the at least one condition is based on at least one of: at least one cell quality threshold associated with a low power wake up signal (LP-WUS), a mobility state of the first apparatus, or capability for supporting LP-WUS of at least one frequency layer; and in accordance with a determination that the at least one condition is satisfied, perform the cell reselection based on a first priority rule, the first priority rule prioritizing a first candidate cell corresponding to a first frequency layer over a second candidate cell corresponding to a second frequency layer, the first frequency layer isupporting the LP-WUS.

[0006] 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 to: transmit, to a first apparatus, a configuration of a cell reselection, the configuration indicating at least one condition for selecting a priority rule for the cell reselection, wherein the at least one condition is based on at least one of: at least one cell quality threshold associated with a low power wake up signal (LP-WUS), a mobility state of the first apparatus, or capability for supporting LP-WUS of at least one frequency layer.

[0007] In a third aspect of the present disclosure, there is provided a method. The method comprises: obtaining a configuration of a cell reselection, the configuration indicating at least one condition for selecting a priority rule for the cell reselection, wherein the at least one condition is based on at least one of: at least one cell quality threshold associated with a low power wake up signal (LP- WUS), a mobility state of the first apparatus, or capability for supporting LP-WUS of at least one frequency layer; and in accordance with a determination that the at least one condition is satisfied, performing the cell reselection based on a first priority rule, the first priority rule prioritizing a first candidate cell corresponding to a first frequency layer over a second candidate cell corresponding to a second frequency layer, the first frequency layer supporting the LP-WUS.

[0008] In a fourth aspect of the present disclosure, there is provided a method. The method comprises: transmitting, to a first apparatus, a configuration of a cell reselection, the configuration indicating at least one condition for selecting a priority rule for the cell reselection, wherein the at least one condition is based on at least one of: at least one cell quality threshold associated with a low power wake up signal (LP-WUS), a mobility state of the first apparatus, or capability for supporting LP-WUS of at least one frequency layer.

[0009] In a fifth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for obtaining a configuration of a cell reselection, the configuration indicating at least one condition for selecting a priority rule for the cell reselection, wherein the at least one condition is based on at least one of: at least one cell quality threshold associated with a low power wake up signal (LP-WUS), a mobility state of the first apparatus, or capability for supporting LP-WUS of at least one frequency layer; and means for in accordance with a determination that the at least one condition is satisfied, performing the cell reselection based on a first priority rule, the first priority rule prioritizing a first candidate cell corresponding to a first frequency layer over a second candidate cell corresponding to a second frequency layer, the first frequency layer supporting the LP- WUS.

[0010] In a sixth aspect of the present disclosure, there is provided a second apparatus. Thesecond apparatus comprises means for transmitting, to a first apparatus, a configuration of a cell reselection, the configuration indicating at least one condition for selecting a priority rule for the cell reselection, wherein the at least one condition is based on at least one of: at least one cell quality threshold associated with a low power wake up signal (LP-WUS), a mobility state of the first apparatus, or capability for supporting LP-WUS of at least one frequency layer.

[0011] 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.

[0012] 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.

[0013] 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

[0014] Some example embodiments will now be described with reference to the accompanying drawings, where:

[0015] FIG. 1 illustrates an example communication environment in which example embodiments of the present disclosure can be implemented;

[0016] FIG. 2A and FIG. 2B illustrate example block diagrams of operations of a first device with a wake-up receiver (WUR) according to some example embodiments of the present disclosure, respectively;

[0017] FIG. 3 illustrates an example signaling flow for cell reselection with priority rule selection according to some example embodiments of the present disclosure;

[0018] FIG. 4 illustrates a flowchart of a method implemented at a first apparatus according to some example embodiments of the present disclosure;

[0019] FIG. 5 illustrates a flowchart of a method implemented at a second apparatus according to some example embodiments of the present disclosure;

[0020] FIG. 6 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

[0021] FIG. 7 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

[0022] Throughout the drawings, the same or similar reference numerals represent the same or similar element.DETAILED DESCRIPTION

[0023] 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.

[0024] 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.

[0025] 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.

[0026] It shall be understood that although the terms “first,” “second” 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. 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.

[0027] 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.

[0028] 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.

[0029] 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 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.

[0030] As used in this application, the term “circuitry” may refer to one or more or all 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.

[0031] 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) 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.

[0032] As used herein, the term “communication network” refers to a network following any suitable communication standards, such as 6G, 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-loT) 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 (1 G), the second generation (2G), 2.5G, 2.75G, the third generation (3G), the fourth generation (4G), 4.5G, the fifth generation (5G) 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.

[0033] As used herein, the term “network device” refers to a node in a communication network viawhich 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 (I AB) 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.

[0034] 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.

[0035] 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 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 thepresent disclosure. It is noted that example embodiments of the present disclosure are equally applicable to other resources in other domains.

[0036] As discussed above, energy efficiency is very critical for UEs without a continuous energy source, e.g., UEs using small rechargeable and single coin cell batteries. Among vertical use cases, sensors and actuators are deployed extensively for monitoring, measuring, charging, etc. Generally, their batteries are not rechargeable and expected to last at least few years. Wearables include smart watches, rings, eHealth related devices, and medical monitoring devices. With typical battery capacity, it is challenging to sustain up to 1-2 weeks as required.

[0037] The power consumption depends on the configured length of wake-up periods, e.g., paging cycle. To meet the battery life requirements above, long extended discontinuous reception (eDRX) cycle may be used, resulting in high latency, which is not suitable for such services with requirements of both long battery life and low latency. For example, in fire detection and extinguishment use case, fire shutters shall be closed and fire sprinklers shall be turned on by the actuators within 1 to 2 seconds from the time the fire is detected by sensors. However, such long eDRX cycle cannot meet the delay requirements. eDRX is apparently not suitable for latency-critical use cases.

[0038] Some mechanisms on low-power wake up signal (LP-WUS) and receiver for new radio (NR) have been proposed, including: the low-power wake-up signal and receiver, including power saving benefit, coverage, system overhead impact, network energy impact and other related aspects; the receiver architecture for low-power wake-up receiver and provide analysis for power consumption, noise figure and etc.; layer one (L1 ) design and procedure changes needed to support the low-power wake-up signal and evaluations for the link performances; higher layer protocol changes needed to support the low-power wake-up signals.

[0039] In RRC I DLE / I NACTI VE modes, it’s observed that significant UE power saving gain (up to more than 90%) is obtained by using LP-WUS or wake up signal receiver (WUR) to trigger UE main radio (MR) paging monitoring compared with existing l-DRX operation (with and without paging early indication (PEI)), if sufficient relaxation to MR radio resource management (RRM) measurement is applied. Further, compared with existing eDRX operation, significant paging latency reduction and moderate UE power saving gain is observed, if LP-WUS monitoring and the corresponding paging monitoring after MR wake-up is performed not restricted within existing paging time window (PTW) of eDRX.

[0040] In RRC CONNECTED mode, it’s observed that moderate UE power saving gain (up to more than 10%) is obtained with marginal impact to capacity by using LP-WUS / WUR to trigger UE MR physical downlink control channel (PDCCH) monitoring compared with existing UE power saving techniques, across different types of extended reality (XR) traffic and system load scenarios. It’s also observed that significant UE power saving gain (up to more than 60%) and moderate user perceivedthroughput (UPT) improvement (up to more than 10%) is obtained tor tile transfer protocol (FTP) and instant messaging (IM) traffic, when the UE MR enters deep sleep state during LR LP-WUS monitoring. Furthermore, the feasibility on serving cell RRM measurement offloading from UE MR to LP-WUR by reasonable evaluation methodology has been verified.

[0041] In some mechanisms, an LP-WUS design commonly applicable to both I DLE / I NACTI VE and CONNECTED modes is specified. For example, on-off keying (OOK) (OOK-1 and / or OOK-4) based LP-WUS with overlaid Orthogonal Frequency-Division Multiplexing (OFDM) sequence(s) over OOK symbol has been specified. The LP-WUS design shall ensure that for I DLE / INACTIVE operation, the same information is delivered irrespective of LP-WUR type. The OFDM sequence may carry information. In addition, at least duty-cycled monitoring of LP-WUS is supported.

[0042] For IDLE / INACTIVE modes, procedure and configuration of LP-WUS indicating paging monitoring triggered by LP-WUS are specified, including at least configuration, sub-grouping and entry / exit condition for LP-WUS monitoring. Low power synchronization signal (LP-SS) with periodicity with Yms for LP-WUR is specified (Y may be predetermined), for synchronization and / or RRM for serving cell. LP-SS is based on OOK-1 and / or OOK-4 waveform with or without overlaid OFDM sequences. Further down selection between with and without overlaid OFDM sequences is to be considered. It is to be noted that for LP-WUR that may receive existing Primary Synchronization Signal (PSS) / Secondary Synchronization Signal (SSS), existing PSS / SSS may be used for synchronization and RRM instead of LP-SS.

[0043] Further RRM relaxation of UE MR for both serving and neighbor cell measurements, and UE serving cell RRM measurement offloaded from MR to LP-WUR are specified, including the necessary conditions.

[0044] For CONNECTED mode, procedures to allow UE MR PDCCH monitoring triggered by LP- WUS including activation and deactivation procedure of LP-WUS monitoring are specified. In CONNECTED mode, UE MR ultra-deep sleep is not considered, and UE RRM or radio link monitoring (RLM) or beam failure detection (BFD) or channel state information (CSI) measurements are performed by MR. The target coverage of LP-WUS and LP-SS shall be the coverage of physical uplink shared channel (PUSCH) for messages. The optimization of LP-WUS signal design for idle / inactive mode may be prioritized over the optimization for connected mode.

[0045] FIG. 1 illustrates 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 first apparatus 110 and a second apparatus 120, can communicate with each other.

[0046] In the example of FIG. 1 , the first apparatus 110 may include a terminal device and the second apparatus 120 may include a network device serving the terminal device. The serving area ofthe second apparatus 120 may be called as a cell (not shown).

[0047] 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 of the second apparatus 120, 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 second apparatus 120 may be another device than a network device. Although illustrated as a terminal device, the first apparatus 110 may be a device other than a terminal device.

[0048] In the following, for the purpose of illustration, some example embodiments are described with the first apparatus 110 operating as a terminal device and the second apparatus 120 operating as a network device. 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.

[0049] In some example embodiments, if the first apparatus 110 is a terminal device and the second apparatus 120 is a network device, a transmission direction from the second apparatus 120 to the first apparatus 110 is referred to as a downlink (DL), while a transmission direction from the first apparatus 110 to the second apparatus 120 is referred to as an uplink (UL). In DL, the second apparatus 120 is a transmitting (TX) device (or a transmitter) and the first apparatus 110 is a receiving (RX) device (or a receiver). In UL, the first apparatus 110 is a TX device (or a transmitter) and the second apparatus 120 is a RX device (or a receiver).

[0050] Communications in the communication environment 100 may be implemented according to any proper communication protocol(s), comprising, but not limited to, cellular communication protocols, 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.

[0051] In some example embodiments, the first apparatus 110 supports a low power mode. That is, the first apparatus 110 is an LP-WUS capable device. For example, in the low power mode, the first apparatus 110 may use a separate low-power wake-up receiver (LR) at the first apparatus 110,instead of the MR. In this way, the power consumption of the first apparatus 110 can be reduced.

[0052] FIG. 2A and FIG. 2B illustrate example block diagrams of operations of an apparatus with a WUR according to some example embodiments of the present disclosure, respectively. In the example of FIG. 2A and FIG. 2B, the first apparatus 110 may be implemented as a UE 200.

[0053] As shown in FIG. 2A, the main radio 210 of UE 200 may be in a sleep mode (or even powered off) for power saving and be activated only upon the reception of the wake-up signal from the network such as the second apparatus 120. In such limited function mode, the main radio 210 may e.g., perform relaxed cell re-selection evaluation / RRM / RLM / BFD measurements. Alternatively, the main radio 210 may not perform these operations. The LP WUS receiver 220 of UE 200 such as an ultra low power wake-up signal receiver may monitor the wake-up signal from the network. The network may trigger the UE 200 to wake-up exactly when needed in an event-driven manner, by transmitting a special wake-up signal (WUS) to the UE 200. The WUS is monitored by the dedicated LR 220 at the UE 200.

[0054] As shown in FIG. 2B, if UE 200 receives the WUS, the LP WUS receiver 220 may trigger the wake-up of the main radio 210 (that is, an ordinary NR transceiver) and communication may start. Thus, the ultra-low power receiver wakes up the main radio 210 and otherwise, the main radio 210 is OFF or kept in a deep sleep mode, as shown in FIG. 2A and FIG. 2B. The assumption is that the low- power wake-up receiver 220 may 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 NR transceiver, by designing a simple (WUS) signal and the use of dedicated hardware for its monitoring, which is only able to receive the WUS.

[0055] In example embodiments of the present disclosure, the WUS is generally refers to a Low- power WUS (LP-WUS), which is currently considered for both idle / inactive mode and connected mode. In some mechanisms, DL reception where LP-WUS may be used to wake up the main radio to receive PDCCH or physical downlink shared channel (PDSCH) (e.g., for paging or other data) has been proposed.

[0056] Furthermore, it has been considered that serving cell evaluations may be offloaded from MR to LR to enable large power saving. The LR may carry the serving cell evaluation related measurements based on new reference signal, low power synchronisation signal, LP-SS, or synchronization signal block (SSB) depending on the LR type. Only serving cell evaluations are being considered to be offloaded to the LR as the coverage of the low power signals and receiver is limited (LR has only 1 RX and higher noise figure).

[0057] Different LR types have been considered, mainly envelope detectors and sequence detectors, or the like. The envelope detectors (ED) LR is capable of detecting ON / OFF keying. The LR has no in-phase quadrature (IQ) branch to perform coherent / sequence detection. This receivermay only receive LP-WUS and LP-SS.

[0058] The sequence detectors (SD) LR uses IQ branches to perform coherent detection. It consumes more power due to the better accuracy of crystal oscillators (XO) used to drive the PLLs. This type of receiver may receive also SSB in addition to LP-WUS.

[0059] In radio access network 1 (RAN1 ), the common understanding is that UE may not support LP-WUS reception on all the bands supported by the UE. It needs to check if there is any issue and specification support needed for I DLE / I NACTI VE UEs.

[0060] As noted in LP-WUS work item the case of LR supporting fewer / subset of bands supported by MR was raised. In some mechanisms, MR and LR are allowed to camp on different layers. However, large amounts of changes are required for camping procedures. A first issue here is coverage. Based on the evaluation results, without introducing enhancement mechanism (e.g. repetition), the coverage performance of LP-WUS may still have some gap compared with the coverage performance of Msg3. Considering the typical frequency point in current NR deployment (e.g. 2.6GHz, 4.9GHz, 3.5GHz), deploy LR in a lower frequency point (e.g. 700MHz, 900MHz) is beneficial from improving LP-SS / LP- WUS’s coverage performance. A second issue here is hardware capabilities. The components in LR- WUR (for instance, RF BPF and LO) have lower processing complexity, which may reduce both the power consumption and the cost of LR. Therefore, if LR support all possible operating bands for MR, the requirement for processing complexity on the hardware components shall increase, which will result in higher power consumption and cost for the LR. Therefore, LR may support e.g., sub-set of bands supported by MR.

[0061] On the other hand, if IDLE mode camping is determined based on legacy approach, it may limit the opportunity for LP-WUS operation, considering LR may only support a limited number of candidate carriers / bands to reduce complexity and power consumption and that LP-WUS maybe deployed only to sub-set of possible carrier / bands. One approach to overcome this limitation is to ask UEs to camp on only the carriers / bands that supported by LR or where LPWUS is deployed / supported, so that UEs which support LP-WUS operation to prioritizes the carriers / bands that support LP-WUS.

[0062] In some mechanisms, LP-WUS or LR specific absolute re-selection priorities or offsets of priorities are introduced that LP-WUS capable devices may apply so that LP-WUS capable UEs prioritise camping on layers where LP-WUS is supported.

[0063] As in practise all the cells of a layer may not support LP-WUS or UE may not be in the coverage area of LP-WUS (determined by entry / exit conditions configured by network), it may not be beneficial for the UE to camp on LP-WUS layer. It is to be noted that it is assumed that LP-WUS may not be usable on whole cell area due to different signal design and simpler receiver structure (LR). UE camping on LP-WUS layer, without being able to use LP-WUS does not provide UE power saving benefits. This maybe negative from system load perspective (if LP-WUS layers are on lower frequencybands, the capacity e.g. for RACH may be limited).

[0064] In order to solve at least part of the above problems or other potential problems, a solution on cell reselection with priority rule selection is proposed. According to embodiments of the present disclosure, a first apparatus such as a terminal device obtains a configuration of a cell reselection. The configuration indicates at least one condition for selecting a priority rule for the cell reselection. For example, the first apparatus may receive the configuration of cell reselection from a second apparatus such as a network device. The at least one condition is based on at least one of: at least one cell quality threshold associated with a low power wake up signal (LP-WUS), a mobility state of the first apparatus, or capability for supporting LP-WUS of at least one frequency layer. If the at least one condition is satisfied, the first apparatus performs the cell reselection based on a first priority rule. The first priority rule prioritizes a first candidate cell corresponding to a first frequency layer supporting the LP-WUS over a second candidate cell corresponding to a second frequency layer. Otherwise, if the at least one condition is not satisfied, the first apparatus may perform the cell reselection based on a second priority rule. The second priority rule may not consider the supporting of LP-WUS.

[0065] In this manner, different priority-based cell reselection approaches can be achieved for different scenarios. The priority-based cell reselection mechanism may thus be adjusted so that it accounts for whether the first apparatus such as UE is in the LP-WUS coverage area such as on a layer in the band that supports LP-WUS and where UE supports LP-WUS. With such cell reselection, load balancing of apparatuses are allowed so that apparatuses that can benefit from LP-WUS are camping in LP-WUS carrier.

[0066] FIG. 3 illustrates an example signaling flow 300 for cell reselection with priority rule selection according to some example embodiments of the present disclosure. For the purposes of discussion, the diagram 300 will be discussed with reference to FIG. 1 , for example, by using the first apparatus 110 and the second apparatus 120.

[0067] In operation, the first apparatus 110 obtains (320) a configuration of a cell reselection (also referred to as cell reselection configuration). The configuration indicates at least one condition for selecting a priority rule for the cell reselection. By way of example, the at least one condition is based on at least one of: at least one cell quality threshold associated with the LP-WUS, a mobility state of the first apparatus 110, or capability for supporting LP-WUS of at least one frequency layer.

[0068] The cell reselection configuration may further include additional cell reselection information, such as a set of candidate cells, or candidate frequencies for cell reselection. The cell reselection configuration and the additional cell reselection information may be included in a single configuration message, or in separate messages. The cell reselection configuration or other configuration message for cell reselection may include assistance information for cell reselection. The assistance information may indicate at least one frequency or at least one neighbor cell applying a wake-up signal, the set ofcandidate cells or candidate frequencies comprising the at least one neighbor cell or the at least one frequency.

[0069] In some embodiments, the second apparatus 120 may transmit (310) the configuration of cell reselection to the first apparatus 110. The first apparatus 110 receives the configuration of cell reselection. For example, the cell reselection configuration may be included in a radio resource control (RRC) message from the second apparatus 120, or system information (SI) such as system information block (SIB) associated with the second apparatus 120, or any suitable message or signaling. Alternatively, at least part of the cell reselection configuration such as the at least one condition or the at least one threshold for the at least one condition may be predefined or specified.

[0070] In one example, if the second apparatus 120 does not provide the first apparatus 110 with the necessary LP-WUS information for each carrier (LP-WUS support and thresholds) in the serving cell, but the first apparatus 110 is required to obtain the information from the (target) cell(s) in the band(s) in which the LP-WUS is supported. Hence, the first apparatus 110 will read the necessary SIB from the carrier(s) in the band in which the first apparatus 110 support LP-WUS autonomously. This may be done prior to reselection and not be done as part of reselection.

[0071] As mentioned, the at least one condition is based on the at least one cell quality threshold. The cell quality may be reference signal received power (RSRP), reference signal received quality (RSRP), or the like. The cell reselection may be based on the measured cell quality and the at least one cell quality threshold.

[0072] By way of example, the at least one cell quality threshold may include but not limited to: a first threshold for starting monitoring the LP-WUS (also referred to as LP-WUS entry threshold), a second threshold for stopping monitoring the LP-WUS (also referred to as LP-WUS exist threshold), a third threshold for offloading a cell measurement to the LR of the first apparatus 110 (also referred to as LP-WUS RRM offloading threshold), a fourth threshold for relaxing a cell measurement by the MR of the first apparatus 110 (also referred to as LP-WUS RRM relaxation threshold), or a fifth threshold for applying the first priority rule. The fifth threshold may be configured for the cell reselection with the first priority rule being selected. That is, if the first priority rule is selected and the fifth threshold is configured, the first apparatus 110 may apply the fifth threshold instead of other thresholds.

[0073] At least one of the first, second third, fourth or fifth threshold may be indicated in the cell reselection configuration. Alternatively, or in addition, an offset between the fifth threshold and one of: the first threshold, the second threshold, the third threshold or the fifth threshold may be indicated in the cell reselection configuration. That is, the fifth threshold may be determined based on the configured offset and the other threshold(s). It is to be understood that these thresholds are only for the purpose of illustration, without suggesting any limitation. Embodiments of the present disclosureis not limited here. The first apparatus 110 may consider one or more of these thresholds for selecting a frequency layer.

[0074] In some example embodiments, the LP-WUS entry threshold and the LP-WUS exist threshold may be configured by the network for the LP-WUS operation, so that these thresholds may be used to determine whether the first apparatus 110 is allowed to use LP-WUS or whether the first apparatus 110 needs to monitor legacy paging. These thresholds may be used as entry or exist conditions for LP-WUS monitoring in idle or inactive mode. Table 1 below shows some example procedures regarding these thresholds.Table 1

[0075] For RRM offloading / relaxation, radio access network 2 (RAN2) has discussed this and made following agreements: for serving cell measurement offloading (i.e., serving cell measurement fully off-loaded to LR and no serving cell measurement via MR is required), RAN2 should focus on specifying the offloading criterion for serving cell for UEs supporting LP-WUS, and assume that RAN4 will define the measurement off-loading requirements for serving cell. RAN2 understand that the RRM measurement of the neigh boring cell may only be performed by MR. Can discuss again if RAN1 inform us otherwise. RAN2 will further discuss the neighbour cell measurement relaxation criteria (if the UE is using LR to measure the serving cell), e.g., considering re-use release (Rel)-16 criteria for ‘not at cell edge’ and ‘low mobility’.

[0076] The first apparatus 110 determines (330) whether the at least one condition is satisfied. If the at least one condition is satisfied, the first apparatus 110 select a first priority rule (also referred to as an LP-WUS specific priority rule). The first apparatus 110 performs (340) the cell reselection (or a cell selection) based on the first priority rule. The first priority rule prioritizes a first candidate cell corresponding to a first frequency layer supporting the LP-WUS over a second candidate cell corresponding to a second frequency layer. In other words, according to the first priority rule, thehigher priority (frequency) layer may be in a band supporting LP-WUS. If the first priority rule is selected, in addition to cell suitability criterions or instead of the cell suitability criterions, the first apparatus 110 may determine whether to reselect to the higher priority layer by considering the network configured LP-WUS entry / exit thresholds and / or network configured LP-WUS RRM offloading / relaxation threshold when determining the layer may be considered for the cell reselection.

[0077] In some example embodiments, if the at least one condition is not satisfied, the first apparatus 110 may select a second priority rule. The first apparatus 110 may perform the cell reselection based on the second priority rule. The second priority rule determines priority of cells of frequency layers without considering capability for supporting LP-WUS. That is, according to the second priority rule, LP-WUS layers are not prioritized. In other words, the first apparatus 110 may use normal (non-LP-WUS specific) absolute reselection priorities.

[0078] In some example embodiments, the first apparatus 110 may perform the cell reselection based on the second priority rule for a time length. After the time length, the first apparatus 110 may continue performing the cell reselection based on the first priority rule. The time length may be predefined. Alternatively, the time length may be configured by the second apparatus 120, for example, in the cell reselection configuration or any other suitable configuration message. Alternatively, the first apparatus 110 may determine the time length based on at least one of: an idle discontinuous reception cycle, or a low power synchronization signal periodicity.

[0079] In some example embodiments, the first priority rule may be configured by the second apparatus 120. The configured first priority rule may be independently from the second priority rule. For example, the first priority rule and the second priority rule may be configured in two separate messages.

[0080] Alternatively, the first priority rule may be determined based on the second priority rule and at least one offset for at least one frequency layer. The second priority rule and the at least one offset may be configured by the second apparatus 120.

[0081] By way of example, if a cell or frequency supports LP-WUS, an offset is added into R value (that is, the priority value determined by the second priority rule) of the cell or the frequency. The offset may be configured per cell or per LP-WUS layers frequency. During the cell reselection procedure, if the serving cell or frequency supports LP-WUS or SIB broadcasts an offset for the serving cell or frequency, cell-ranking criterion R, for serving cell is added with the offset. If a neighboring cell or frequency supports LP-WUS, or SIB broadcasts the offset for the neighboring cell or frequency, cell-ranking criterion R, for neighboring cell is added with the offset.

[0082] In this way, the cell or frequency that supports LP-WUS may be prioritized. During the cell reselection procedure, if the cell or frequency supports LP-WUS or SIB broadcasts with indication that the cell or frequency may be prioritized, the first apparatus 110 may prioritize this cell or frequency atmost.

[0083] The first apparatus 110 may perform a cell reselection evaluation on at least a part of the set of candidate cells or candidate frequencies based on the cell reselection configuration and the assistance information mentioned above. In this way, the network is able to direct the apparatuses such as UEs supporting WUS to a proper cell or frequency applying the WUS. As such, the power consumption is reduced, while the latency and mobility performance are ensured.

[0084] In this manner, the first apparatus 110 may have different priorities configured / supported for the frequency layers that support LP-WUS. Those priorities may be applied if the at least one condition is satisfied. For example, if the target cell on the (LP-WUS) layer, exceeds the quality threshold set for LP-WUS entry, the LP-WUS specific priorities may be applied.

[0085] As mentioned, the first apparatus 110 selects the priority rule based on the at least one condition. In an example embodiments, the at least one condition may include a first condition that the first apparatus 110 is camping on a frequency layer not supporting the LP-WUS. For example, if the first condition is satisfied, the first apparatus 110 may choose the LP-WUS specific priority rule. The at least one condition may further include a second condition that a candidate cell supports the LP-WUS. The candidate cell may be a strongest cell.

[0086] The at least one condition may further include a third condition that a cell quality of the candidate cell supporting the LP-WUS satisfies the at least one cell quality threshold. For example, if the cell quality such as RSRP or RSRQ is higher than the LP-WUS entry threshold, or higher than the LP-WUS RRM offloading or relaxation threshold, the third condition is satisfied. The cell quality of the candidate cell may be based on at least one of: a measurement of SSB by a main radio of the first apparatus 110 or a measurement of LP-SS by the MR or LR of the first apparatus 110.

[0087] The at least one condition may further include a fourth condition that the mobility state of the first apparatus 110 indicates that the first apparatus 110 is stationary or with mobility lower than a mobility threshold. For example, if the first apparatus 110 is stationary or with low mobility, the fourth condition is satisfied. The at least one condition may further include a fifth condition that the first apparatus 110 is not at a cell edge. In some example embodiments, the mobility state of the first apparatus 110 or whether the first apparatus 110 is at the cell edge may be based on a comparison between a measured cell quality and at least one threshold for relaxing a cell measurement.

[0088] The at least one condition may further include a sixth condition that the first apparatus 110 is camping on a frequency layer supporting the LP-WUS and a time duration for a cell quality of a candidate cell on the frequency layer exceeding the at least one cell quality threshold exceeds a time length. The time length may be predefined, configured by the second apparatus 120, or alternatively determined by the first apparatus 110 based on an idle discontinuous reception cycle, and / or an LP- SS periodicity.

[0089] It is to be understood that these conditions are only for the purpose of illustration, without suggesting any limitation. These conditions may be applied separately, or in any combination. Any other suitable condition may be applied. Embodiments of the present disclosure is not limited here.

[0090] In some example embodiments, if the first apparatus 110 is camping on a frequency layer not supporting the LP-WUS, the first apparatus 110 may determine whether to perform the cell reselection based on the first priority rule based on the at least one condition. As an example, if a target cell on a prioritized frequency layer based on the first priority rule supports the LP-WUS and a cell quality of the target cell satisfies the at least one cell quality threshold, the first apparatus 110 may select the target cell. As another example, if the mobility state of the first apparatus 110 indicates a mobility lower than a mobility threshold, the first apparatus 110 may select the target cell on the prioritized frequency layer based on the first priority rule.

[0091] In some example embodiments, the cell quality of the target cell satisfies the at least one cell quality threshold based the cell quality being higher than or equal to at least one of: a first threshold for starting monitoring the LP-WUS on the target cell, a third threshold for offloading a measurement of the target cell to a LP-WUS receiver (LR) of the first apparatus 110, or a fourth threshold for relaxing a measurement of the target cell by a main radio (MR) of the first apparatus 110, or a fifth threshold for applying the first priority rule.

[0092] In some example embodiments, offsets are introduced to cell quality metrics (i.e. RSRP and / or RSRQ) so that the first apparatus 110 may not be expected to re-select to the higher priority LP-WUS layers unless the cells exceed said threshold(s).

[0093] These offsets may be specifically configured as new LP-WUS reselection thresholds or be based on configured thresholds for entry / exit and / or RRM offloading / relaxation. In one possible embodiment, the LP-WUS layer cell suitability criterion is adjusted / changed based on configured thresholds.

[0094] In one possible additional embodiment, the mobility state of the first apparatus 110 may be considered. The mobility state of the first apparatus 110 may show medium / high mobility meaning that the first apparatus 110 does not get significant benefit from LP-WUS e.g. due to frequent changes between the LP-WUS entry / exit conditions when performing cell reselections. In this case, the above offsets to the cell quality metrics shall be ignored (considered 0), or / and the first apparatus 110 will use normal (non-LP-WUS specific) absolute reselection priorities.

[0095] In other possible additional embodiment, the measurement relaxation criterions for the first apparatus 110 not at cell edge, stationary first apparatus 110 or the first apparatus 110 with low mobility are considered. The measurement relaxation criterions may be used to determine e.g. whether the first apparatus 110 is stationary or not, the first apparatus 110 with low mobility or not or not at cell edge or not. Apparatuses that are not stationary or at cell edge or not low mobility does notget significant benefit from LP-WUS e.g. due to not being able to use LP-WUS or frequent changes between the LP-WUS entry / exit conditions. In this case, the above offsets to the cell quality metrics may be ignored (considered 0), or / and the first apparatus 110 will use normal (non-LP-WUS specific) absolute reselection priorities.

[0096] In some embodiments the first apparatus 110 considers whether or not the strongest cell of the higher priority target layer supports LP-WUS (i.e. has LP-WUS configured via system information of the cell). For example, if the strongest cell (to which the first apparatus 110 is re-selecting) on the target higher priority layer does not support LP-WUS, the first apparatus 110 may not apply any alteration in thresholds or fall-backs to normal priorities (instead of LP-WUS specific priorities for LR capable UEs).

[0097] In some related embodiments, the first apparatus 110 may consider the presence of RRM measurement offloading / relaxation threshold configuration to determine whether the cell is suitable for re-selection.

[0098] In some embodiments, the first apparatus 110 may consider measurements made using SSB and / or LP-SS by either the LR or the MR, to support the cell reselection process.

[0099] In some related embodiments, when the first apparatus 110 is camping on layer that supporting LP-WUS, but the first apparatus 110 has not exceeded LP-WUS related threshold for a given time (such as the time length mention above), the first apparatus 110 may choose to fall-back using normal (non-LP-WUS capable) devices priorities. Alternatively, the first apparatus 110 may stop using LP-WUS capable device specific offsets to priorities. The related thresholds may be LP-WUS entry and / or RRM offloading / relaxation.

[0100] In some embodiments, if the first apparatus 110 falls back to normal / legacy priorities (from LP-WUS / LR capable device priorities), then those normal priorities are applied for a certain time. The certain time (also referred to as a time length or a timer) may be predefined, configured or determined by the first apparatus 110. For example, the related timer may be dependent on the applied idle DRX cycle lengths and / or LP-SS periodicity.

[0101] In some embodiments, the behaviour of the first apparatus 110 such as the UE behaviour, may depend whether the first apparatus 110 supports LP-WUS on the frequency band of the target cell.

[0102] Further embodiments regarding the cell reselection with the priority rule selection based on the at least one condition will be described. The cell reselection configuration such as absolute priority reselection configuration may be provided by the second apparatus 120 such as the network via dedicated or broadcast signalling with special configuration for LP-WUS capable devices. The cell reselection configuration may include also specific configuration for the suitability threshold(s) to be applied for the LP-WUS layer(s), for example, Threshx, HighQ =Threshx, HighQ_LP us.

[0103] In one example of implementations, the first apparatus 110 may be configured to obtain the LP-WUS entry threshold (such as ThLP-wus, entry) from the LP-WUS target cell to be used as suitability threshold, that is, Threshx, HighQ = Th p-wus, entry.

[0104] When the first apparatus 110 is camping on layer that does not support LP-WUS, the first apparatus 110 may evaluate the need / possibility to do a reselection to higher priority layer.

[0105] If the (target) cell in the higher priority layer is indicated to support LP-WUS by provided information, the first apparatus 110 may determine if the cell quality of the target cell exceeds (or meets) the configured LP-WUS related threshold. Otherwise, the first apparatus 110 may fall back to using normal (non-LP-WUS specific, or wo LP-WUS specific offsets) absolute priorities

[0106] In some examples, the first apparatus 110 may apply the normal absolute reselection priorities for a certain time after the first apparatus 110 has deemed the target (LP-WUS) layer not to meet the applied threshold(s).

[0107] In some example embodiment, the second apparatus 120 may provide the first apparatus 110 with absolute priority reselection configuration via dedicated or broadcast signalling with special configuration for LP-WUS capable devices. The configuration may include also mobility state related configurations. When the first apparatus 110 is camping on layer that does not support LP-WUS, the first apparatus 110 may evaluate the need / possibility to do a reselection to higher priority layer.

[0108] If the first apparatus 110 is in low mobility state, the first apparatus 110 applies the LP-WUS specific absolute priority reselection thresholds or offsets. Otherwise, the first apparatus 110 may fall back to using normal (non-LP-WUS specific, or wo LP-WUS specific offsets) absolute priorities.

[0109] As mentioned, the priority rule selection may be based on the mobility state of the first apparatus 110 such as UE mobility state. Table 2 below illustrates information related to UE mobility state. The UE mobility state may the measurement relaxation criterions. Table 3 shows the measurement relaxations based on mobility and UE location. Table 2 and Table 3 may be based on a standard or technical specification (TS).Table 2_- If number of cell reselections during time period TcRmax is greater than or equal to NCR_M but less than or equal to NCR_H.High-mobility state criteria:- If number of cell reselections during time period Tc max is greater than NCR_H.The UE shall not consider consecutive reselections where a cell is reselected again right after one reselection for mobility state detection criteria. If the UE is capable of HSDN and the cellEquivalentSize is configured, the UE counts the number of cell reselections for this cell as cellEquivalentSize configured for this cell.State transitions:The UE shall:- if the criteria for High-mobility state is detected:- enter High-mobility state.- else if the criteria for Medium-mobility state is detected:- enter Medium-mobility state.- else if criteria for either Medium- or High-mobility state is not detected during time period TcRmaxHyst:- enter Normal-mobility state.If the UE is in High- or Medium-mobility state, the UE shall apply the speed dependent scaling rules as defined in a standard.Scaling rulesUE shall apply the following scaling rules:- If neither Medium- nor High-mobility state is detected:- no scaling is applied.- If High-mobility state is detected:- Add the sf-High of "Speed dependent Scali ng Factor for Qhyst" to Qhyst if broadcasted in system information;- For NR cells, multiply TreselectionN by the sf-High of "Speed dependent ScalingFactor for Treselec- tionNR1' if broadcasted in system information;- For EUTRA cells, multiply TreselectionEUT A by the sf-High of "Speed dependent ScalingFactor for TreselectionEUT A11if broadcasted in system information.- If Medium-mobility state is detected:- Add the sf-Medium of "Speed dependent ScalingFactor for Qhyst" to Qhyst if broadcasted in system information;- For NR cells, multiply TreselectionNR by the sf-Medium of "Speed dependent ScalingFactor for TreselectionNR" if broadcasted in system information;- For EUTRA cells, multiply TreselectionEUTRA by the sf-Medium of "Speed dependent ScalingFactor for TreselectionEUTRA1' if broadcasted in system information.In case scaling is applied to any TreselectionRAT parameter, the UE shall round up the result after all scalings to the nearest second.Table 3

[0110] Alternatively, or in addition, in some example embodiments, when the first apparatus 110 is camping on layer that does not support LP-WUS, the first apparatus 110 evaluates the need / possibility to do a reselection to a layer supporting LP-WUS or related measurement relaxations. If the reselection to the layer is due to LP-WUS support on that layer, the first apparatus 110 may evaluate the applicability of using LP-WUS and / or measurement relaxation on the layer, prior to reselecting to the layer. Reselection may be based on higher priority, equal priority or to lower priority (e.g. if source cell quality is low). Hence, to obtain the necessary reselection evaluation information, the first apparatus 110 may read the system information containing the relevant LP-WUS, measurement relaxation and related thresholds from the target cell / layer. The first apparatus 110 may receive the relevant LP-WUS, measurement relaxation and related thresholds by dedicated signalling or broadcast signalling from the network.

[0111] Based on measurements performed on the target layer and the obtained LP-WUS / relaxed measurement thresholds, the first apparatus 110 may reselect to the target layer if LP-WUS monitoring and / or measurement relaxation may be applied or used. This option may use the higher priority options in above examples, but use of higher priority layers (option) is not a pre-request.

[0112] With these embodiments, it allows load balancing of devices so that only devices that can benefit from LP-WUS are camping in LP-WUS carrier.

[0113] As mentioned, the first apparatus 110 may perform (340) the cell reselection based on the selected priority rule. The first apparatus 110 then may determine priorities for frequency layers and reselect the target cell based on the priorities and other conditions such as cell qualities of candidate cells. Table 4 illustrates several cell reselection criteria which may be applied in combination with the present cell reselection with priority rule selection. Some thresholds in Table 4 may be adjusted based on the at least one threshold described herein.Table 4Otherwise, cell reselection to a cell on a higher priority NR frequency or inter-RAT frequency than the serving frequency shall be performed if:- A cell of a higher priority RAT / frequency fulfils Srxlev > Threshx, Highp during a time interval Treselection- RAT; and- More than 1 second has elapsed since the UE camped on the current serving cell.Cell reselection to a cell on an equal priority NR frequency shall be based on ranking for intra-frequency cell reselection as defined in a standard.If threshServingLowQ is broadcast in system information and more than 1 second has elapsed since the UE camped on the current serving cell, cell reselection to a cell on a lower priority NR frequency or inter- RAT frequency than the serving frequency shall be performed if:- The serving cell fulfils Squal < Threshsen / ing, LOWQ and a cell of a lower priority NR or E-UTRAN RAT / frequency fulfils Squal > Threshx, LOWQ during a time interval TreselectionRAT.Otherwise, cell reselection to a cell on a lower priority NR frequency or inter-RAT frequency than the serving frequency shall be performed if:- The serving cell fulfils Srxlev < Threshsen / ing, LOWP and a cell of a lower priority RAT / frequency fulfils Srxlev> Threshx, LOWP during a time interval TreselectionRAT; and- More than 1 second has elapsed since the UE camped on the current serving cell.Cell reselection to a higher priority RAT / frequency shall take precedence over a lower priority RAT / fre- quency if multiple cells of different priorities fulfil the cell reselection criteria.If more than one cell meets the above criteria, the UE shall reselect a cell as follows:- If the highest-priority frequency is an NR frequency, the highest ranked cell among the cells on the highest priority frequency(ies) meeting the criteria according to a standard;- If the highest-priority frequency is from another RAT, the strongest cell among the cells on the highest priority frequency(ies) meeting the criteria of that RAT.It would be appreciated that some example specifications and embodiments are providec above, and the detailed description may be varied.

[0115] Example embodiments for cell reselection with priority rule selection are described above with reference to the signaling flow 300. With these embodiments, cell reselection for UE capable of LP-WUS can be enhanced. Moreover, power saving can be enhanced by prioritizing the frequency layer supporting LP-WUS in suitable scenarios. Reduced power consumption. These embodiments enable load balancing of devices so that only devices that can benefit from LP-WUS are camping in LP-WUS carrier. The power consumption can also be reduced.

[0116] FIG. 4 shows a flowchart of an example method 400 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 400 will be described from the perspective of the first apparatus 110 in FIG. 1.

[0117] At block 410, the first apparatus 110 obtains a configuration of a cell reselection. The configuration indicates at least one condition for selecting a priority rule for the cell reselection. Theat least one condition is based on at least one of: at least one cell quality threshold associated with a low power wake up signal (LP-WUS), a mobility state of the first apparatus, or capability for supporting LP-WUS of at least one frequency layer.

[0118] At block 420, the first apparatus 110 determines whether the at least one condition is satisfied. If the at least one condition is satisfied, at block 430, the first apparatus 110 performs the cell reselection based on a first priority rule. The first priority rule prioritizes a first candidate cell corresponding to a first frequency layer over a second candidate cell corresponding to a second frequency layer. The first frequency layer supports the LP-WUS.

[0119] In some example embodiments, the configuration is obtained from at least one of: a radio resource control (RRC) message from a second apparatus, or system information associated with the second apparatus.

[0120] In some example embodiments, the at least one cell quality threshold comprises at least one of: a first threshold for starting monitoring the LP-WUS, a second threshold for stopping monitoring the LP-WUS, a third threshold for offloading a cell measurement to a LP-WUS receiver (LR) of the first apparatus, a fourth threshold for relaxing a cell measurement by a main radio (MR) of the first apparatus, or a fifth threshold for applying the first priority rule.

[0121] In some example embodiments, the configuration indicates at least one of: the first threshold, the second threshold, the third threshold, the fourth threshold, the fifth threshold, or an offset between the fifth threshold and one of: the first threshold, the second threshold, the third threshold or the fifth threshold.

[0122] In some example embodiments, the at least one condition comprises at least one of: a first condition that the first apparatus is camping on a frequency layer not supporting the LP-WUS, a second condition that a candidate cell supports the LP-WUS, a third condition that a cell quality of the candidate cell supporting the LP-WUS satisfies the at least one cell quality threshold, a fourth condition that the mobility state of the first apparatus indicates that the first apparatus is stationary or with mobility lower than a mobility threshold, a fifth condition that the first apparatus is not at a cell edge, or a sixth condition that the first apparatus is camping on a frequency layer supporting the LP- WUS and a time duration for a cell quality of a candidate cell on the frequency layer exceeding the at least one cell quality threshold exceeds a time length.

[0123] In some example embodiments, the cell quality of the candidate cell is based on at least one of: a measurement of a synchronization signal block (SSB) by a main radio (MR) of the first apparatus or a measurement of a low power synchronization signal (LP-SS) by the MR or a LP-WUS receiver (LR) of the first apparatus.

[0124] In some example embodiments, the mobility state of the first apparatus 110 or whether the first apparatus 110 is at the cell edge is based on a comparison between a measured cell quality andat least one threshold for relaxing a neighboring cell measurement.

[0125] In some example embodiments, the method 400 further comprises: in accordance with a determination that the at least one condition is not satisfied, performing the cell reselection based on a second priority rule, the second priority rule determining priority of cells of frequency layers without considering capability for supporting LP-WUS.

[0126] In some example embodiments, the method 400 further comprises: performing the cell reselection based on the second priority rule for a time length.

[0127] In some example embodiments, the first priority rule is configured by the second apparatus and is independently from the second priority rule. Alternatively, the first priority rule may be determined based on the second priority rule and at least one offset for at least one frequency layer.

[0128] In some example embodiments, the time length is predefined, or configured by a second apparatus, or determined based on at least one of: an idle discontinuous reception cycle, or a low power synchronization signal (LP-SS) periodicity.

[0129] In some example embodiments, the method 400 further comprises: in accordance with a determination that the first apparatus is camping on a frequency layer not supporting the LP-WUS, determining whether to perform the cell reselection based on the first priority rule based on the at least one condition.

[0130] In some example embodiments, determining whether to perform the cell reselection based on the first priority rule comprises at least one of: in accordance with a determination that a target cell on a prioritized frequency layer based on the first priority rule supports the LP-WUS and a cell quality of the target cell satisfies the at least one cell quality threshold, select the target cell; and in accordance with a determination that the mobility state of the first apparatus indicates a mobility lower than a mobility threshold, select the target cell on the prioritized frequency layer based on the first priority rule.

[0131] In some example embodiments, the cell quality of the target cell satisfies the at least one cell quality threshold based the cell quality being higher than or equal to at least one of: a first threshold for starting monitoring the LP-WUS on the target cell, a third threshold for offloading a measurement of the target cell to a LP-WUS receiver (LR) of the first apparatus, or a fourth threshold for relaxing a measurement of the target cell by a main radio (MR) of the first apparatus, or a fifth threshold for applying the first priority rule.

[0132] In some example embodiments, the first apparatus comprises a terminal device, and the second apparatus comprises a network device.

[0133] FIG. 5 shows a flowchart of an example method 500 implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 500 will be described from the perspective of the second apparatus 120 in FIG. 1.

[0134] At block 510, the second apparatus 120 transmits, to a first apparatus, a configuration of a cell reselection. The configuration indicates at least one condition for selecting a priority rule for the cell reselection. The at least one condition is based on at least one of: at least one cell quality threshold associated with a low power wake up signal (LP-WUS), a mobility state of the first apparatus, or capability for supporting LP-WUS of at least one frequency layer.

[0135] In some example embodiments, the configuration is comprised in at least one of: a radio resource control (RRC) message, or system information associated with the second apparatus.

[0136] In some example embodiments, the at least one cell quality threshold comprises at least one of: a first threshold for starting monitoring the LP-WUS, a second threshold for stopping monitoring the LP-WUS, a third threshold for offloading a cell measurement to a LP-WUS receiver (LR) of the first apparatus, a fourth threshold for relaxing a cell measurement by a main radio (MR) of the first apparatus, or a fifth threshold for applying the first priority rule.

[0137] In some example embodiments, the configuration indicates at least one of: the first threshold, the second threshold, the third threshold, the fourth threshold, the fifth threshold, or an offset between the fifth threshold and one of: the first threshold, the second threshold, the third threshold or the fifth threshold.

[0138] In some example embodiments, the at least one condition comprises at least one of: a first condition that the first apparatus is camping on a frequency layer not supporting the LP-WUS, a second condition that a candidate cell supports the LP-WUS, a third condition that a cell quality of the candidate cell supporting the LP-WUS satisfies the at least one cell quality threshold, a fourth condition that the mobility state of the first apparatus indicates that the first apparatus is stationary or with mobility lower than a mobility threshold, a fifth condition that the first apparatus is not at a cell edge, or a sixth condition that the first apparatus is camping on a frequency layer supporting the LP- WUS and a time duration for a cell quality of a candidate cell on the frequency layer exceeding the at least one cell quality threshold exceeds a time length.

[0139] In some example embodiments, the method 500 further comprises: transmitting a configuration of the time length to the first apparatus.

[0140] In some example embodiments, the time length is determined based on at least one of: an idle discontinuous reception cycle of the first apparatus, or a low power synchronization signal (LP- SS) periodicity.

[0141] In some example embodiments, the first apparatus comprises a terminal device, and the second apparatus comprises a network device.

[0142] In some example embodiments, a first apparatus capable of performing any of the method 400 (for example, the first apparatus 110 in FIG. 1 ) may comprise means for performing the respective operations of the method 400. The means may be implemented in any suitable form. For example, themeans may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the first apparatus 110 in FIG. 1 .

[0143] In some example embodiments, the first apparatus comprises means for obtaining a configuration of a cell reselection, the configuration indicating at least one condition for selecting a priority rule for the cell reselection, wherein the at least one condition is based on at least one of: at least one cell quality threshold associated with a low power wake up signal (LP-WUS), a mobility state of the first apparatus, or capability for supporting LP-WUS of at least one frequency layer; and means for in accordance with a determination that the at least one condition is satisfied, performing the cell reselection based on a first priority rule, the first priority rule prioritizing a first candidate cell corresponding to a first frequency layer over a second candidate cell corresponding to a second frequency layer, the first frequency layer supporting the LP-WUS.

[0144] In some example embodiments, the configuration is obtained from at least one of: a radio resource control (RRC) message from a second apparatus, or system information associated with the second apparatus.

[0145] In some example embodiments, the at least one cell quality threshold comprises at least one of: a first threshold for starting monitoring the LP-WUS, a second threshold for stopping monitoring the LP-WUS, a third threshold for offloading a cell measurement to a LP-WUS receiver (LR) of the first apparatus, a fourth threshold for relaxing a cell measurement by a main radio (MR) of the first apparatus, or a fifth threshold for applying the first priority rule.

[0146] In some example embodiments, the configuration indicates at least one of: the first threshold, the second threshold, the third threshold, the fourth threshold, the fifth threshold, or an offset between the fifth threshold and one of: the first threshold, the second threshold, the third threshold or the fifth threshold.

[0147] In some example embodiments, the at least one condition comprises at least one of: a first condition that the first apparatus is camping on a frequency layer not supporting the LP-WUS, a second condition that a candidate cell supports the LP-WUS, a third condition that a cell quality of the candidate cell supporting the LP-WUS satisfies the at least one cell quality threshold, a fourth condition that the mobility state of the first apparatus indicates that the first apparatus is stationary or with mobility lower than a mobility threshold, a fifth condition that the first apparatus is not at a cell edge, or a sixth condition that the first apparatus is camping on a frequency layer supporting the LP- WUS and a time duration for a cell quality of a candidate cell on the frequency layer exceeding the at least one cell quality threshold exceeds a time length.

[0148] In some example embodiments, the cell quality of the candidate cell is based on at least one of: a measurement of a synchronization signal block (SSB) by a main radio (MR) of the first apparatus or a measurement of a low power synchronization signal (LP-SS) by the MR or a LP-WUS receiver(LR) of the first apparatus.

[0149] In some example embodiments, the mobility state of the first apparatus or whether the first apparatus is at the cell edge is based on a comparison between a measured cell quality and at least one threshold for relaxing a neighboring cell measurement.

[0150] In some example embodiments, the first apparatus further comprises: means for in accordance with a determination that the at least one condition is not satisfied, performing the cell reselection based on a second priority rule, the second priority rule determining priority of cells of frequency layers without considering capability for supporting LP-WUS.

[0151] In some example embodiments, the cell reselection is performed based on the second priority rule for a time length.

[0152] In some example embodiments, the first priority rule is configured by the second apparatus and is independently from the second priority rule, or the first priority rule is determined based on the second priority rule and at least one offset for at least one frequency layer.

[0153] In some example embodiments, the time length is predefined, or configured by a second apparatus, or determined based on at least one of: an idle discontinuous reception cycle, or a low power synchronization signal (LP-SS) periodicity.

[0154] In some example embodiments, the first apparatus further comprises: means for in accordance with a determination that the first apparatus is camping on a frequency layer not supporting the LP- WUS, determining whether to perform the cell reselection based on the first priority rule based on the at least one condition.

[0155] In some example embodiments, if a target cell on a prioritized frequency layer based on the first priority rule supports the LP-WUS and a cell quality of the target cell satisfies the at least one cell quality threshold, the target cell may be selected. If the mobility state of the first apparatus indicates a mobility lower than a mobility threshold, the target cell on the prioritized frequency layer based on the first priority rule may be selected.

[0156] In some example embodiments, the cell quality of the target cell satisfies the at least one cell quality threshold based the cell quality being higher than or equal to at least one of: a first threshold for starting monitoring the LP-WUS on the target cell, a third threshold for offloading a measurement of the target cell to a LP-WUS receiver (LR) of the first apparatus, or a fourth threshold for relaxing a measurement of the target cell by a main radio (MR) of the first apparatus, or a fifth threshold for applying the first priority rule.

[0157] In some example embodiments, a second apparatus capable of performing any of the method 500 (for example, the second apparatus 120 in FIG. 1 ) may comprise means for performing the respective operations of the method 500. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatusmay be implemented as or included the second apparatus 120 in FIG. 1.

[0158] In some example embodiments, the second apparatus comprises means for transmitting, to a first apparatus, a configuration of a cell reselection, the configuration indicating at least one condition for selecting a priority rule for the cell reselection, wherein the at least one condition is based on at least one of: at least one cell quality threshold associated with a low power wake up signal (LP-WUS), a mobility state of the first apparatus, or capability for supporting LP-WUS of at least one frequency layer.

[0159] In some example embodiments, the configuration is comprised in at least one of: a radio resource control (RRC) message, or system information associated with the second apparatus.

[0160] In some example embodiments, the at least one cell quality threshold comprises at least one of: a first threshold for starting monitoring the LP-WUS, a second threshold for stopping monitoring the LP-WUS, a third threshold for offloading a cell measurement to a LP-WUS receiver (LR) of the first apparatus, a fourth threshold for relaxing a cell measurement by a main radio (MR) of the first apparatus, or a fifth threshold for applying the first priority rule.

[0161] In some example embodiments, the configuration indicates at least one of: the first threshold, the second threshold, the third threshold, the fourth threshold, the fifth threshold, or an offset between the fifth threshold and one of: the first threshold, the second threshold, the third threshold or the fifth threshold.

[0162] In some example embodiments, the at least one condition comprises at least one of: a first condition that the first apparatus is camping on a frequency layer not supporting the LP-WUS, a second condition that a candidate cell supports the LP-WUS, a third condition that a cell quality of the candidate cell supporting the LP-WUS satisfies the at least one cell quality threshold, a fourth condition that the mobility state of the first apparatus indicates that the first apparatus is stationary or with mobility lower than a mobility threshold, a fifth condition that the first apparatus is not at a cell edge, or a sixth condition that the first apparatus is camping on a frequency layer supporting the LP- WUS and a time duration for a cell quality of a candidate cell on the frequency layer exceeding the at least one cell quality threshold exceeds a time length.

[0163] In some example embodiments, the second apparatus further comprises: means for transmitting a configuration of the time length to the first apparatus.

[0164] In some example embodiments, the time length is determined based on at least one of: an idle discontinuous reception cycle of the first apparatus, or a low power synchronization signal (LP-SS) periodicity.

[0165] FIG. 6 is a simplified block diagram of a device 600 that is suitable for implementing example embodiments of the present disclosure. The device 600 may be provided to implement a communication device, for example, the first apparatus 110 or the second apparatus 120 as shown inFIG. 1. As shown, the device 600 includes one or more processors 610, one or more memories 620 coupled to the processor 610, and one or more communication modules 640 coupled to the processor 610.

[0166] The communication module 640 is for bidirectional communications. The communication module 640 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 640 may include at least one antenna.

[0167] The processor 610 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 600 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.

[0168] The memory 620 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) 624, 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) 622 and other volatile memories that will not last in the power-down duration.

[0169] A computer program 630 includes computer executable instructions that are executed by the associated processor 610. The instructions of the program 630 may include instructions for performing operations / acts of some example embodiments of the present disclosure. The program 630 may be stored in the memory, e.g., the ROM 624. The processor 610 may perform any suitable actions and processing by loading the program 630 into the RAM 622.

[0170] The example embodiments of the present disclosure may be implemented by means of the program 630 so that the device 600 may perform any process of the disclosure as discussed with reference to FIG. 3 to FIG. 5. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0171] In some example embodiments, the program 630 may be tangibly contained in a computer readable medium which may be included in the device 600 (such as in the memory 620) or other storage devices that are accessible by the device 600. The device 600 may load the program 630 from the computer readable medium to the RAM 622 for execution. In some example embodiments, the computer readable medium may include any types of non-transitory storage medium, such asROM, 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).

[0172] FIG. 7 shows an example of the computer readable medium 700 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 700 has the program 630 stored thereon.

[0173] 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.

[0174] 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 computer-executable 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. Machineexecutable 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.

[0175] 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.

[0176] 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 variousprocesses and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

[0177] 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.

[0178] 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 or in any suitable subcombination.

[0179] 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 disclosed as example forms of implementing the claims.

Claims

WHAT IS CLAIMED IS:1 . A first apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus to: obtain a configuration of a cell reselection, the configuration indicating at least one condition for selecting a priority rule for the cell reselection, wherein the at least one condition is based on at least one of: at least one cell quality threshold associated with a low power wake up signal (LP-WUS), a mobility state of the first apparatus, or capability for supporting LP-WUS of at least one frequency layer; and in accordance with a determination that the at least one condition is satisfied, perform the cell reselection based on a first priority rule, the first priority rule prioritizing a first candidate cell corresponding to a first frequency layer over a second candidate cell corresponding to a second frequency layer, the first frequency layer supporting the LP-WUS.

2. The first apparatus of claim 1 , wherein the configuration is obtained from at least one of: a radio resource control (RRC) message from a second apparatus, or system information associated with the second apparatus.

3. The first apparatus of claim 1 or 2, wherein the at least one cell quality threshold comprises at least one of: a first threshold for starting monitoring the LP-WUS, a second threshold for stopping monitoring the LP-WUS, a third threshold for offloading a cell measurement to a LP-WUS receiver (LR) of the first apparatus, a fourth threshold for relaxing a cell measurement by a main radio (MR) of the first apparatus, or a fifth threshold for applying the first priority rule.

4. The first apparatus of claim 3, wherein the configuration indicates at least one of: the first threshold, the second threshold, the third threshold, the fourth threshold, the fifth threshold, or an offset between the fifth threshold and one of: the first threshold, the second threshold, the third threshold or the fifth threshold.

5. The first apparatus of any of claims 1 -4, wherein the at least one condition comprises at least one of: a first condition that the first apparatus is camping on a frequency layer not supporting the LP-WUS, a second condition that a candidate cell supports the LP-WUS, a third condition that a cell quality of the candidate cell supporting the LP-WUS satisfies the at least one cell quality threshold, a fourth condition that the mobility state of the first apparatus indicates that the first apparatus is stationary or with mobility lower than a mobility threshold, a fifth condition that the first apparatus is not at a cell edge, or a sixth condition that the first apparatus is camping on a frequency layer supporting the LP-WUS and a time duration for a cell quality of a candidate cell on the frequency layer exceeding the at least one cell quality threshold exceeds a time length.

6. The first apparatus of claim 5, wherein the cell quality of the candidate cell is based on at least one of: a measurement of a synchronization signal block (SSB) by a main radio (MR) of the first apparatus or a measurement of a low power synchronization signal (LP-SS) by the MR or a LP-WUS receiver (LR) of the first apparatus.

7. The first apparatus of claim 5, wherein the mobility state of the first apparatus or whether the first apparatus is at the cell edge is based on a comparison between a measured cell quality and at least one threshold for relaxing a neighboring cell measurement.

8. The first apparatus of any of claims 1-7, wherein the first apparatus is further caused to: in accordance with a determination that the at least one condition is not satisfied, perform the cell reselection based on a second priority rule, the second priority rule determining priority of cells of frequency layers without considering capability for supporting LP-WUS.

9. The first apparatus of claim 8, wherein the first apparatus is further caused to: perform the cell reselection based on the second priority rule for a time length.

10. The first apparatus of claim 8 or 9, wherein: the first priority rule is configured by the second apparatus and is independently from the second priority rule, or the first priority rule is determined based on the second priority rule and at least one offset for at leastone frequency layer.

11. The first apparatus of claim 5 or 9, wherein the time length is predefined, or configured by a second apparatus, or determined based on at least one of: an idle discontinuous reception cycle, or a low power synchronization signal (LP-SS) periodicity.

12. The first apparatus of any of claims 1-11 , wherein the first apparatus is further caused to: in accordance with a determination that the first apparatus is camping on a frequency layer not supporting the LP-WUS, determine whether to perform the cell reselection based on the first priority rule based on the at least one condition.

13. The first apparatus of claim 12, wherein determining whether to perform the cell reselection based on the first priority rule comprises at least one of: in accordance with a determination that a target cell on a prioritized frequency layer based on the first priority rule supports the LP-WUS and a cell quality of the target cell satisfies the at least one cell quality threshold, select the target cell; and in accordance with a determination that the mobility state of the first apparatus indicates a mobility lower than a mobility threshold, select the target cell on the prioritized frequency layer based on the first priority rule.

14. The first apparatus of claim 13, wherein the cell quality of the target cell satisfies the at least one cell quality threshold based the cell quality being higher than or equal to at least one of: a first threshold for starting monitoring the LP-WUS on the target cell, a third threshold for offloading a measurement of the target cell to a LP-WUS receiver (LR) of the first apparatus, or a fourth threshold for relaxing a measurement of the target cell by a main radio (MR) of the first apparatus, or a fifth threshold for applying the first priority rule.

15. The first apparatus of any of claims 1 -14, wherein the first apparatus comprises a terminal device, and the second apparatus comprises a network device.

16. A second apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, causethe second apparatus to: transmit, to a first apparatus, a configuration of a cell reselection, the configuration indicating at least one condition for selecting a priority rule for the cell reselection, wherein the at least one condition is based on at least one of: at least one cell quality threshold associated with a low power wake up signal (LP- WUS), a mobility state of the first apparatus, or capability for supporting LP-WUS of at least one frequency layer.

17. The second apparatus of claim 16, wherein the configuration is comprised in at least one of: a radio resource control (RRC) message, or system information associated with the second apparatus.

18. The second apparatus of claim 16 or 17, wherein the at least one cell quality threshold comprises at least one of: a first threshold for starting monitoring the LP-WUS, a second threshold for stopping monitoring the LP-WUS, a third threshold for offloading a cell measurement to a LP-WUS receiver (LR) of the first apparatus, a fourth threshold for relaxing a cell measurement by a main radio (MR) of the first apparatus, or a fifth threshold for applying the first priority rule.

19. The second apparatus of claim 18, wherein the configuration indicates at least one of: the first threshold, the second threshold, the third threshold, the fourth threshold, the fifth threshold, or an offset between the fifth threshold and one of: the first threshold, the second threshold, the third threshold or the fifth threshold.

20. The second apparatus of any of claims 16-19, wherein the at least one condition comprises at least one of: a first condition that the first apparatus is camping on a frequency layer not supporting the LP-WUS, a second condition that a candidate cell supports the LP-WUS, a third condition that a cell quality of the candidate cell supporting the LP-WUS satisfies the at least one cell quality threshold, a fourth condition that the mobility state of the first apparatus indicates that the first apparatus is stationary or with mobility lower than a mobility threshold,a fifth condition that the first apparatus is not at a cell edge, or a sixth condition that the first apparatus is camping on a frequency layer supporting the LP-WUS and a time duration for a cell quality of a candidate cell on the frequency layer exceeding the at least one cell quality threshold exceeds a time length.21 . The second apparatus of claim 20, wherein the second apparatus is further caused to: transmit a configuration of the time length to the first apparatus.

22. The second apparatus of claim 21 , wherein the time length is determined based on at least one of: an idle discontinuous reception cycle of the first apparatus, or a low power synchronization signal (LP-SS) periodicity.

23. The second apparatus of any of claims 16-22, wherein the first apparatus comprises a terminal device, and the second apparatus comprises a network device.

24. A method comprising: obtaining, at a first apparatus, a configuration of a cell reselection, the configuration indicating at least one condition for selecting a priority rule for the cell reselection, wherein the at least one condition is based on at least one of: at least one cell quality threshold associated with a low power wake up signal (LP- WUS), a mobility state of the first apparatus, or capability for supporting LP-WUS of at least one frequency layer; and in accordance with a determination that the at least one condition is satisfied, performing the cell reselection based on a first priority rule, the first priority rule prioritizing a first candidate cell corresponding to a first frequency layer over a second candidate cell corresponding to a second frequency layer, the first frequency layer supporting the LP-WUS.

25. A method comprising: transmitting, at a second apparatus to a first apparatus, a configuration of a cell reselection, the configuration indicating at least one condition for selecting a priority rule for the cell reselection, wherein the at least one condition is based on at least one of: at least one cell quality threshold associated with a low power wake up signal (LP-WUS), a mobility state of the first apparatus, or capability for supporting LP-WUS of at least one frequency layer.

26. A first apparatus comprising: means for obtaining a configuration of a cell reselection, the configuration indicating at least onecondition for selecting a priority rule for the cell reselection, wherein the at least one condition is based on at least one of: at least one cell quality threshold associated with a low power wake up signal (LP-WUS), a mobility state of the first apparatus, or capability for supporting LP-WUS of at least one frequency layer; and means for in accordance with a determination that the at least one condition is satisfied, performing the cell reselection based on a first priority rule, the first priority rule prioritizing a first candidate cell corresponding to a first frequency layer over a second candidate cell corresponding to a second frequency layer, the first frequency layer supporting the LP-WUS.

27. A second apparatus comprising: means for transmitting, to a first apparatus, a configuration of a cell reselection, the configuration indicating at least one condition for selecting a priority rule for the cell reselection, wherein the at least one condition is based on at least one of: at least one cell quality threshold associated with a low power wake up signal (LP-WUS), a mobility state of the first apparatus, or capability for supporting LP-WUS of at least one frequency layer.

28. A computer readable medium comprising instructions stored thereon for causing an apparatus at least to perform the method of claim 24 or the method of claim 25.

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