WO2022058004A1

WO2022058004A1 - Method for beam management

Info

Publication number: WO2022058004A1
Application number: PCT/EP2020/075857
Authority: WO
Inventors: Sami-Jukka Hakola; Daniela Laselva; Timo Koskela; Jorma Johannes Kaikkonen; Christian Rom
Original assignee: Nokia Technologies Oy
Priority date: 2020-09-16
Filing date: 2020-09-16
Publication date: 2022-03-24

Abstract

An apparatus comprising: means for receiving at least two sets of configurations for wake-up signal monitoring, wherein a first set of configurations comprises a first search space set for wake-up signal monitoring, and a second set of configurations comprises multiple second search space sets for wake-up signal monitoring and associated uplink radio resources to be used; means for monitoring time elapsed from a transmission of a latest beam report of a serving beam of the apparatus to a network; means for detecting, in response to said time not exceeding a predetermined threshold, wake-up signals using the first set of configurations; means for detecting, in response to said time being equal or exceeding the predetermined threshold, wake-up signals using the second set of configurations; and means for transmitting a beam report of a serving beam of the apparatus to the network.

Description

METHOD FOR BEAM MANAGEMENT

TECHNICAL FIELD

[0001] The present invention relates to beam management measurements.

BACKGROUND

[0002] In the standardization of 3GPP 5G NR, one of the recently introduced concepts is a Wake-up-Signal (WUS). For a user equipment (UE) to be able to operate in discontinuous reception (DRX) operation in RRC Connected mode, said UE must periodically perform beam management related operations. Now the network may send a Wake-Up-Signal (WUS) to the UE to indicate whether the UE is required to start a drx- OnDurationTimer, i.e. the UE is required to be active mode for a while and monitor its Physical Downlink Control channel (PDCCH). In case the WUS does not indicate the UE to wake up and start the timer, the UE can skip the PDCCH monitoring during DRX- OnDuration for achieving power saving.

[0003] However, when using long DRX cycles (i.e. non-active time), the beam quality of the UE may deteriorate during the DRX cycle. In the worst case, the beam could be lost especially, if the cell coverage area is small and fast moving beam blockers appear.

[0004] This may lead to a low PDCCH decoding likelihood at the time that precedes the next DRX-OnDuration, which in turn may cause the UE to miss the WUS and the corresponding data that the WUS indicates. If the UE loses its beam alignment, it needs to start the beam failure recovery (BFR) procedure. This will require additional signalling overhead and will disrupt the normal operation of UE until beam alignment is reestablished. However, the BFR procedure is slow, and such disruption may take several 100s of ms.

SUMMARY

[0005] Now, an improved method and technical equipment implementing the method have been invented, by which the above problems are alleviated. Various aspects include a method, an apparatus and a non-transitory computer readable medium comprising a computer program, or a signal stored therein, which are characterized by what is stated in the independent claims. Various details of the embodiments are disclosed in the dependent claims and in the corresponding images and description.

[0006] The scope of protection sought for various embodiments of the invention is set out by the independent claims. The embodiments and features, if any, described in this specification that do not fall under the scope of the independent claims are to be interpreted as examples useful for understanding various embodiments of the invention.

[0007] According to a first aspect, there is provided an apparatus configured to operate in a connected mode of a radio resource protocol (RRC), the apparatus comprising means for receiving at least two sets of configurations for wake-up signal monitoring, wherein a first set of configurations comprises a first search space set for wake-up signal monitoring, and a second set of configurations comprises multiple second search space sets for wakeup signal monitoring; means for monitoring time elapsed from a transmission of a latest beam report of a serving beam of the apparatus to a network; means for detecting, in response to said time not exceeding a predetermined threshold, wake-up signals using the first set of configurations; means for detecting, in response to said time being equal or exceeding the predetermined threshold, wake-up signals using the second set of configurations; and means for transmitting a beam report of a serving beam of the apparatus to the network.

[0008] According to an embodiment, the second set of configurations comprises associated uplink radio resources to be used, and said means for transmitting the beam report of the serving beam of the apparatus to the network is configured to use the uplink radio resources associated with the second set of configurations.

[0009] According to an embodiment, the search space sets of the second set of configurations are associated to same or different Control Resource Sets (CORESETs). [0010] According to an embodiment, a number of CORESETs to which search space sets are associated to depends on a capability of the apparatus regarding a number of simultaneous receive panels.

[0011] According to an embodiment, the apparatus further comprises means for monitoring a number of monitoring occasions since the latest wake-up signalling from the network indicating the apparatus to wake-up, and means for detecting, in response to said number of monitoring occasions exceeding a predetermined second threshold, wake-up signals using the second set of configurations.

[0012] According to an embodiment, the uplink radio resources provided for beam reporting have a fixed time domain relationship to the WUS monitoring occasions in time. [0013] According to an embodiment, the apparatus further comprises means for receiving an indication from the network to start detecting the wake-up signals using either first set or the second set of configurations.

[0014] According to an embodiment, the apparatus is configured to operate in a frequency band of millimeter waves (mmWave) of 3GPP 5G NR specifications. [0015] An apparatus according to a second aspect is configured to operate in a connected mode of a radio resource protocol (RRC), the apparatus comprising at least one processor and at least one memory, said at least one memory stored with computer program code thereon, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: receive at least two sets of configurations for wake-up signal monitoring, wherein a first set of configurations comprises a first search space set for wake-up signal monitoring, and a second set of configurations comprises multiple second search space sets for wake-up signal monitoring; monitor time elapsed from a transmission of a latest beam report of a serving beam of the apparatus to a network; detect, in response to said time not exceeding a predetermined threshold, wake-up signals using the first set of configurations; or detect, in response to said time being equal or exceeding the predetermined threshold, wake-up signals using the second set of configurations; and transmit a beam report of a serving beam of the apparatus to the network.

[0016] A method according to a third aspect comprises receiving, in an apparatus configured to operate in a connected mode of a radio resource protocol (RRC), at least two sets of configurations for wake-up signal monitoring, wherein a first set of configurations comprises a first search space set for wake-up signal monitoring, and a second set of configurations comprises multiple second search space sets for wake-up signal monitoring; monitoring time elapsed from a transmission of a latest beam report of a serving beam of the apparatus to a network; detecting, in response to said time not exceeding a predetermined threshold, wake-up signals using the first set of configurations; or detecting, in response to said time being equal or exceeding the predetermined threshold, wake-up signals using the second set of configurations; and transmitting a beam report of a serving beam of the apparatus to the network.

[0017] An apparatus according to a fourth aspect comprises means for providing at least one user equipment with at least two sets of configurations for wake-up signal monitoring, wherein a first set of configurations comprises a first search space set for wake-up signal monitoring, and a second set of configurations comprises multiple second search space sets for wake-up signal monitoring; means for monitoring time elapsed from a reception of a latest beam report of a serving beam of the user equipment; means for transmitting, in response to said time not exceeding a predetermined threshold, wake-up signals to the user equipment using the first set of configurations; means for transmitting, in response to said time being equal or exceeding the predetermined threshold, wake-up signals to the user equipment using the second set of configurations; and means for receiving a beam report of a serving beam of the user equipment.

[0018] An apparatus according to a fifth aspect comprises at least one processor and at least one memory, said at least one memory stored with computer program code thereon, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: provide at least one user equipment with at least two sets of configurations for wake-up signal monitoring, wherein a first set of configurations comprises a first search space set for wake-up signal monitoring, and a second set of configurations comprises multiple second search space sets for wake-up signal monitoring; monitor time elapsed from a reception of a latest beam report of a serving beam of the user equipment; transmit, in response to said time not exceeding a predetermined threshold, wake-up signals to the user equipment using the first set of configurations; or transmit, in response to said time being equal or exceeding the predetermined threshold, wake-up signals to the user equipment using the second set of configurations; and receive a beam report of a serving beam of the user equipment.

[0019] A method according to a sixth aspect comprises providing at least one user equipment with at least two sets of configurations for wake-up signal monitoring, wherein a first set of configurations comprises a first search space set for wake-up signal monitoring, and a second set of configurations comprises multiple second search space sets for wake-up signal monitoring; monitoring time elapsed from a reception of a latest beam report of a serving beam of the user equipment; transmitting, in response to said time not exceeding a predetermined threshold, wake-up signals to the user equipment using the first set of configurations; or transmitting, in response to said time being equal or exceeding the predetermined threshold, wake-up signals to the user equipment using the second set of configurations; and receiving a beam report of a serving beam of the user equipment.

[0020] Computer readable storage media according to further aspects comprise code for use by an apparatus, which when executed by a processor, causes the apparatus to perform the above methods.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] For a more complete understanding of the example embodiments, reference is now made to the following descriptions taken in connection with the accompanying drawings in which:

[0022] Fig. 1 shows a schematic block diagram of an apparatus for incorporating the embodiments;

[0023] Fig. 2 shows schematically a layout of an apparatus according to an example embodiment;

[0024] Fig. 3 shows a part of an exemplifying radio access network;

[0025] Fig. 4 shows a beam alignment procedure for 5G NR networks;

[0026] Fig. 5 shows an example of wake-up signalling (WUS);

[0027] Fig. 6 shows an example of problems in WUS relating to long DRX cycles;

[0028] Fig. 7 shows a flow chart for a beam management and WUS procedure in a user equipment according to an embodiment;

[0029] Fig. 8 shows an example of multi-WUS configuration of the UE and the related WUS monitoring illustrating some embodiments; and

[0030] Fig. 9 shows a flow chart for a beam management and WUS procedure in a network element according to an embodiment. DETAILED DESCRIPTON OF SOME EXAMPLE EMBODIMENTS

[0031] The following describes in further detail suitable apparatus and possible mechanisms carrying out the beam management operations. While the following focuses on beam management in 5G networks, the embodiments as described further below are by no means limited to be implemented in said networks only, but they are applicable in any network supporting beam management operations, such as in 4G/LTE networks.

[0032] In this regard, reference is first made to Figures 1 and 2, where Figure 1 shows a schematic block diagram of an exemplary apparatus or electronic device 50, which may incorporate the necessary functions for the beam management operations according to the embodiments. Figure 2 shows a layout of an apparatus according to an example embodiment. The elements of Figs. 1 and 2 will be explained next.

[0033] The electronic device 50 may for example be a mobile terminal or user equipment of a wireless communication system. The apparatus 50 may comprise a housing 30 for incorporating and protecting the device. The apparatus 50 further may comprise a display 32 and a keypad 34. Instead of the keypad, the user interface may be implemented as a virtual keyboard or data entry system as part of a touch-sensitive display.

[0034] The apparatus may comprise a microphone 36 or any suitable audio input which may be a digital or analogue signal input. The apparatus 50 may further comprise an audio output device, such as anyone of: an earpiece 38, speaker, or an analogue audio or digital audio output connection. The apparatus 50 may also comprise a battery 40 (or the device may be powered by any suitable mobile energy device such as solar cell, fuel cell or clockwork generator). The apparatus may further comprise a camera 42 capable of recording or capturing images and/or video. The apparatus 50 may further comprise an infrared port 41 for short range line of sight communication to other devices. In other embodiments the apparatus 50 may further comprise any suitable short-range communication solution such as for example a Bluetooth wireless connection or a USB/firewire wired connection.

[0035] The apparatus 50 may comprise a controller 56 or processor for controlling the apparatus 50. The controller 56 may be connected to memory 58 which may store both user data and instructions for implementation on the controller 56. The memory may be random access memory (RAM) and/or read only memory (ROM). The memory may store computer-readable, computer-executable software including instructions that, when executed, cause the controller/processor to perform various functions described herein. In some cases, the software may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein. The controller 56 may further be connected to codec circuitry 54 suitable for carrying out coding and decoding of audio and/or video data or assisting in coding and decoding carried out by the controller.

[0036] The apparatus 50 may further comprise a first card reader 46 and a second card reader 48, which may be supplied with a first subscriber identity module (SIM/USIM) associated with a first network and a second SIM/USIM associated with a second network, respectively, for providing user information and being suitable for providing authentication information for authentication and authorization of the user at the first network and the second network.

[0037] The apparatus 50 may comprise radio interface circuitry 52 connected to the controller and suitable for generating wireless communication signals for example for communication with a cellular communications network, a wireless communications system or a wireless local area network. The apparatus 50 may further comprise an antenna 44 connected to the radio interface circuitry 52 for transmitting radio frequency signals generated at the radio interface circuitry 52 to other apparatus(es) and for receiving radio frequency signals from other apparatus(es).

[0038] In the following, different exemplifying embodiments will be described using, as an example of an access architecture to which the embodiments may be applied, a radio access architecture based on Long Term Evolution Advanced (LTE Advanced, LTE-A) or new radio (NR, 5G), without restricting the embodiments to such an architecture, however. A person skilled in the art appreciates that the embodiments may also be applied to other kinds of communications networks having suitable means by adjusting parameters and procedures appropriately. Some examples of other options for suitable systems are the universal mobile telecommunications system (UMTS) radio access network (UTRAN or E-UTRAN), long term evolution (LTE, the same as E-UTRA), wireless local area network (WLAN or WiFi), worldwide interoperability for microwave access (WiMAX), Bluetooth®, personal communications services (PCS), ZigBee®, wideband code division multiple access (WCDMA), systems using ultra-wideband (UWB) technology, sensor networks, mobile ad-hoc networks (MANETs) and Internet protocol multimedia subsystems (IMS) or any combination thereof.

[0039] Figure 3 depicts examples of simplified system architectures only showing some elements and functional entities, all being logical units, whose implementation may differ from what is shown. The connections shown in Figure 3 are logical connections; the actual physical connections may be different. It is apparent to a person skilled in the art that the system typically comprises also other functions and structures than those shown in Figure 3. The embodiments are not, however, restricted to the system given as an example but a person skilled in the art may apply the solution to other communication systems provided with necessary properties.

[0040] The example of Figure 3 shows a part of an exemplifying radio access network. [0041] Figure 3 shows user devices 300 and 302 configured to be in a wireless connection on one or more communication channels in a cell with an access node (such as (e/g)NodeB) 304 providing the cell. The physical link from a user device to a (e/g)NodeB is called uplink or reverse link and the physical link from the (e/g)NodeB to the user device is called downlink or forward link. It should be appreciated that (e/g)NodeBs or their functionalities may be implemented by using any node, host, server or access point etc. entity suitable for such a usage.

[0042] A communication system typically comprises more than one (e/g)NodeB in which case the (e/g)NodeBs may also be configured to communicate with one another over links, wired or wireless, designed for the purpose. These links may be used for signaling purposes. The (e/g)NodeB is a computing device configured to control the radio resources of communication system it is coupled to. The NodeB may also be referred to as a base station, an access point or any other type of interfacing device including a relay station capable of operating in a wireless environment. The (e/g)NodeB includes or is coupled to transceivers. From the transceivers of the (e/g)NodeB, a connection is provided to an antenna unit that establishes bi-directional radio links to user devices. The antenna unit may comprise a plurality of antennas or antenna elements. The (e/g)NodeB is further connected to core network 310 (CN or next generation core NGC). Depending on the system, the counterpart on the CN side can be a serving gateway (S-GW, routing and forwarding user data packets), packet data network gateway (P-GW), for providing connectivity of user devices (UEs) to external packet data networks, or mobile management entity (MME), etc. The CN may comprise network entities or nodes that may be referred to management entities. Examples of the network entities comprise at least an Access and Mobility Management Function (AMF).

[0043] The user device (also called a user equipment (UE), a user terminal, a terminal device, a wireless device, a mobile station (MS) etc.) illustrates one type of an apparatus to which resources on the air interface are allocated and assigned, and thus any feature described herein with a user device may be implemented with a corresponding network apparatus, such as a relay node, an eNB, and an gNB. An example of such a relay node is a layer 3 relay (self-backhauling relay) towards the base station.

[0044] The user device typically refers to a portable computing device that includes wireless mobile communication devices operating with or without a subscriber identification module (SIM), including, but not limited to, the following types of devices: a mobile station (mobile phone), smartphone, personal digital assistant (PDA), handset, device using a wireless modem (alarm or measurement device, etc.), laptop and/or touch screen computer, tablet, game console, notebook, and multimedia device. It should be appreciated that a user device may also be a nearly exclusive uplink only device, of which an example is a camera or video camera loading images or video clips to a network. A user device may also be a device having capability to operate in Internet of Things (loT) network which is a scenario in which objects are provided with the ability to transfer data over a network without requiring human-to-human or human-to-computer interaction.

Accordingly, the user device may be an loT-device. The user device may also utilize cloud. In some applications, a user device may comprise a small portable device with radio parts (such as a watch, earphones or eyeglasses) and the computation is carried out in the cloud. The user device (or in some embodiments a layer 3 relay node) is configured to perform one or more of user equipment functionalities. The user device may also be called a subscriber unit, mobile station, remote terminal, access terminal, user terminal or user equipment (UE) just to mention but a few names or apparatuses.

[0045] Various techniques described herein may also be applied to a cyber-physical system (CPS) (a system of collaborating computational elements controlling physical entities). CPS may enable the implementation and exploitation of massive amounts of interconnected ICT devices (sensors, actuators, processors microcontrollers, etc.) embedded in physical objects at different locations. Mobile cyber physical systems, in which the physical system in question has inherent mobility, are a subcategory of cyberphysical systems. Examples of mobile physical systems include mobile robotics and electronics transported by humans or animals.

[0046] Additionally, although the apparatuses have been depicted as single entities, different units, processors and/or memory units (not all shown in Fig. 1) may be implemented.

[0047] 5G enables using multiple input - multiple output (MIMO) antennas, many more base stations or nodes than the LTE (a so-called small cell concept), including macro sites operating in co-operation with smaller stations and employing a variety of radio technologies depending on service needs, use cases and/or spectrum available. 5G mobile communications supports a wide range of use cases and related applications including video streaming, augmented reality, different ways of data sharing and various forms of machine type applications (such as (massive) machine-type communications (mMTC), including vehicular safety, different sensors and real-time control. 5G is expected to have multiple radio interfaces, namely below 6GHz, cmWave and mmWave, and also capable of being integrated with existing legacy radio access technologies, such as the LTE. Integration with the LTE may be implemented, at least in the early phase, as a system, where macro coverage is provided by the LTE and 5G radio interface access comes from small cells by aggregation to the LTE. In other words, 5G is planned to support both inter- RAT operability (such as LTE-5G) and inter-RI operability (inter-radio interface operability, such as below 6GHz - cmWave, below 6GHz - cmWave - mmWave). One of the concepts considered to be used in 5G networks is network slicing in which multiple independent and dedicated virtual sub-networks (network instances) may be created within the same infrastructure to run services that have different requirements on latency, reliability, throughput and mobility.

[0048] Frequency bands for 5G NR are separated into two frequency ranges: Frequency Range 1 (FR1) including sub-6 GHz frequency bands, i.e. bands traditionally used by previous standards, but also new bands extended to cover potential new spectrum offerings from 410 MHz to 7125 MHz, and Frequency Range 2 (FR2) including frequency bands from 24.25 GHz to 52.6 GHz. Thus, FR2 includes the bands in the mmWave range, which due to their shorter range and higher available bandwidth require somewhat different approach in radio resource management compared to bands in the FR1.

[0049] The current architecture in LTE networks is fully distributed in the radio and fully centralized in the core network. The low latency applications and services in 5G require to bring the content close to the radio which leads to local break out and multiaccess edge computing (MEC). 5G enables analytics and knowledge generation to occur at the source of the data. This approach requires leveraging resources that may not be continuously connected to a network such as laptops, smartphones, tablets and sensors. MEC provides a distributed computing environment for application and service hosting. It also has the ability to store and process content in close proximity to cellular subscribers for faster response time. Edge computing covers a wide range of technologies such as wireless sensor networks, mobile data acquisition, mobile signature analysis, cooperative distributed peer-to-peer ad hoc networking and processing also classifiable as local cloud/fog computing and grid/mesh computing, dew computing, mobile edge computing, cloudlet, distributed data storage and retrieval, autonomic self-healing networks, remote cloud services, augmented and virtual reality, data caching, Internet of Things (massive connectivity and/or latency critical), critical communications (autonomous vehicles, traffic safety, real-time analytics, time-critical control, healthcare applications).

[0050] The communication system is also able to communicate with other networks, such as a public switched telephone network or the Internet 312, or utilize services provided by them. The communication network may also be able to support the usage of cloud services, for example at least part of core network operations may be carried out as a cloud service (this is depicted in Fig. 3 by “cloud” 314). The communication system may also comprise a central control entity, or a like, providing facilities for networks of different operators to cooperate for example in spectrum sharing.

[0051] Edge cloud may be brought into radio access network (RAN) by utilizing network function virtualization (NFV) and software defined networking (SDN). Using edge cloud may mean access node operations to be carried out, at least partly, in a server, host or node operationally coupled to a remote radio head or base station comprising radio parts. It is also possible that node operations will be distributed among a plurality of servers, nodes or hosts. Application of cloudRAN architecture enables RAN real time functions being carried out at the RAN side (in a distributed unit, DU) and non-real time functions being carried out in a centralized manner (in a centralized unit, CU 308).

[0052] It should also be understood that the distribution of tasks between core network operations and base station operations may differ from that of the LTE or even be nonexistent. Some other technology advancements probably to be used are Big Data and all-IP, which may change the way networks are being constructed and managed. 5G (or new radio, NR) networks are being designed to support multiple hierarchies, where MEC servers can be placed between the core and the base station or nodeB (gNB). It should be appreciated that MEC can be applied in 4G networks as well. The gNB is a next generation Node B (or, new Node B) supporting the 5G network (i.e., the NR).

[0053] 5G may also utilize non-terrestrial nodes 306, e.g. access nodes, to enhance or complement the coverage of 5G service, for example by providing backhauling, wireless access to wireless devices, service continuity for machine-to -machine (M2M) communication, service continuity for Internet of Things (loT) devices, service continuity for passengers on board of vehicles, ensuring service availability for critical communications and/or ensuring service availability for future railway/maritime/aeronautical communications. The non-terrestrial nodes may have fixed positions with respect to the Earth surface or the non-terrestrial nodes may be mobile nonterrestrial nodes that may move with respect to the Earth surface. The non-terrestrial nodes may comprise satellites and/or HAPSs. Satellite communication may utilize geostationary earth orbit (GEO) satellite systems, but also low earth orbit (LEO) satellite systems, in particular mega-constellations (systems in which hundreds of (nano)satellites are deployed). Each satellite in the mega-constellation may cover several satellite-enabled network entities that create on-ground cells. The on-ground cells may be created through an on-ground relay node 304 or by a gNB located on-ground or in a satellite.

[0054] A person skilled in the art appreciates that the depicted system is only an example of a part of a radio access system and in practice, the system may comprise a plurality of (e/g)NodeBs, the user device may have an access to a plurality of radio cells and the system may comprise also other apparatuses, such as physical layer relay nodes or other network elements, etc. At least one of the (e/g)NodeBs or may be a Home(e/g)nodeB. Additionally, in a geographical area of a radio communication system a plurality of different kinds of radio cells as well as a plurality of radio cells may be provided. Radio cells may be macro cells (or umbrella cells) which are large cells, usually having a diameter of up to tens of kilometers, or smaller cells such as micro-, femto- or picocells. The (e/g)NodeBs of Fig. 1 may provide any kind of these cells. A cellular radio system may be implemented as a multilayer network including several kinds of cells. Typically, in multilayer networks, one access node provides one kind of a cell or cells, and thus a plurality of (e/g)NodeBs are required to provide such a network structure.

[0055] For fulfilling the need for improving the deployment and performance of communication systems, the concept of “plug-and-play” (e/g)NodeBs has been introduced. Typically, a network which is able to use “plug-and-play” (e/g)Node Bs, includes, in addition to Home (e/g)NodeBs (H(e/g)nodeBs), a home node B gateway, or HNB-GW (not shown in Fig. 1). A HNB Gateway (HNB-GW), which is typically installed within an operator’s network may aggregate traffic from a large number of HNBs back to a core network.

[0056] The Radio Resource Control (RRC) protocol is used in various wireless communication systems for defining the air interface between the UE and a base station, such as eNB/gNB. This protocol is specified by 3GPP in in TS 36.331 for LTE and in TS 38.331 for 5G. In terms of the RRC, the UE may operate in LTE and in 5G in an idle mode or in a connected mode, wherein the radio resources available for the UE are dependent on the mode where the UE at present resides. In 5G, the UE may also operate in inactive mode. In the RRC idle mode, the UE has no connection for communication, but the UE is able to listen to page messages. In the RRC connected mode, the UE may operate in different states, such as CELL DCH (Dedicated Channel), CELL FACH (Forward Access Channel), CELL PCH (Cell Paging Channel) and URA PCH (URA Paging Channel). The UE may communicate with the eNB/gNB via various logical channels like Broadcast Control Channel (BCCH), Paging Control Channel (PCCH), Common Control Channel (CCCH), Dedicated Control Channel (DCCH), Dedicated Traffic Channel (DTCH).

[0057] The transitions between the states is controlled by a state machine of the RRC. When the UE is powered up, it is in a disconnected mode/idle mode. The UE may transit to RRC connected mode with an initial attach or with a connection establishment. If there is no activity from the UE for a short time, eNB/gNB may suspend its session by moving to RRC Inactive and can resume its session by moving to RRC connected mode. The UE can move to the RRC idle mode from the RRC connected mode or from the RRC inactive mode.

[0058] When the UE is operating in Frequency Range 2 (FR2), the radio beam alignment procedure between the gNB and the UE for both reception and transmission (Rx/Tx) includes the following steps with the corresponding phases P-1, P-2 and P-3 identified in Figure 4: a) the gNB transmitting reference signals in different directions using different Tx beams (P-1 and P-2); b) the UE providing feedback on the best gNB beam (P-1 and P-2); c) the UE transmitting reference signals in different directions using different Tx beam configurations (P-3); d) the gNB providing feedback on the best UE beam (P-2 and P-3).

[0059] In Frequency Range 1 (FR1), beam forming is only used from the gNB perspective and the UE uses a single beam, wherein the Rx/Tx beam alignment procedure consists in phases P-1 and P-2.

[0060] In FR2, both gNB and UE are expected to operate using “narrow” beams meaning that gNB operates using radiation patterns narrower than sector-wide beams and UE operates using radiation patterns narrower than omni-directional beams, as illustrated in Figure 4. The reasons for the beam-based operations depend on the need for an increased array/antenna gain to compensate the higher coupling loss at mmWaves, but also due to technological limitations. For instance, the achievable power amplifier (PA) output power decreases as a function of the carrier frequency for any PA technology class, and when going to higher carrier frequencies more and more of the Effective/Equivalent Isotropic Radiated Power (EIRP) needs to be provided with an increased antenna/array gain. That can be achieved by narrowing the radiation patterns, i.e. using narrow beams/dir ections.

[0061] Beam-based operation requires a good beam correspondence between the gNB and UE, which is challenging to maintain since, with very narrow beams and, therefore, a large degree of freedom in the spatial domain, it is rather sensitive to blockages and beam misalignment between gNB and UE, as well as to mobility and rotation effects of the UE. [0062] For a UE to be able to operate in discontinuous reception (DRX) operation in RRC Connected mode in FR2, said UE must periodically perform beam management related operations, such as channel state information reference signals/ synchronization signal blocks (CSI-RS/SSB) measurements, as well as to report periodically the result of these measurements to the network. In addition to these operations defined in 3 GPP Release 15 standard set, the following Release 16 introduced a concept of a Wake-up- Signal (WUS). WUS can also be referred to as DCP, i.e. DCI (Downlink Control Information) Format Scrambled with PS-RNTI (Power Saving- Radio Network Temporary Identifier). For further details of the DCP configuration that makes use of DCI format 2 6 a reference is made to the specification 3GPP TS 38.331 Rel-16.

[0063] Figure 5 illustrates the concept of WUS. The network indicates in a WUS to the UE whether the UE is required to start a drx-OnDurationTimer, i.e. the UE is required to be on active time and monitor PDCCH, if it receives a wake-up indication in the WUS occasions preceding the drx-OnDuration. In case the WUS does not indicate the UE to wake up/start the timer (e.g. the NW has no downlink data or any other control information to be transmitted during the next OnDuration for the given UE), the UE can skip the PDCCH monitoring during DRX-OnDuration for achieving power saving. The UE can be configured with one or more monitoring occasions for WUS detection before the onDuration, as illustrated in Figure 5.

[0064] However, when using long DRX cycles (i.e. non-active time), the serving beam switch procedure may be delayed, and the serving beam quality may deteriorate during the DRX cycle. In the worst case, the beam could be lost especially in FR2, where the cell coverage area is small and fast moving blockers may appear.

[0065] This may lead to a low PDCCH decoding likelihood at the (time that precedes the) next DRX-OnDuration, which in turn may cause the UE to miss the WUS and the corresponding data that the WUS indicates. If the UE loses its beam alignment, it needs to start the beam failure recovery (BFR) procedure. This will require additional signalling overhead and will disrupt the normal operation of UE until beam alignment is re- established. Such disruption may take several 100s of ms, as the phases Pl, P2 and P3 have to be completed again.

[0066] Figure 6 illustrates the above problems, especially relating to long DRX cycles, where the last measurement report, sent by the UE using a first beam, which is available at the network and received during the previous DRX-OnDurationl, may not be indicative of the beam quality changes occurring during the DRX cycle, which may lead to the deterioration, or even the failure of the first beam, before it could be switched to another beam during the subsequent DRX-OnDuration2. Consequently, the network sends WUS on the first beam, which may not be detected by the UE, leading to missing the corresponding PDCCH and data.

[0067] For solving the problem, the beam failure recovery (BFR) procedure is far from optimal due to inherent slowness, as explained above. The problem could be solved by a network implementation, where UEs with high mobility shall not be configured with long DRX cycles. However, a UE in low mobility configured with long DRX cycle changing from low mobility to high mobility would undergo the same problem before the DRX cycle could be eventually reconfigured.

[0068] Another solution would be to transmit WUS continuously in beam sweeping manner from multiple beams to the UE. Such an approach would provide beam diversity but would require reserving lots of network resources. Also, the ambiguity would remain at the gNB side about on which beam the UE was able to receive the WUS in order to decide which beam to use during onDuration for the UE.

[0069] In the following, an enhanced method for allowing a UE to minimize the occurrence of beam misalignments upon wake-up signal monitoring will be described in more detail, in accordance with various embodiments.

[0070] The method, which is disclosed in Figure 7 as reflecting the operation of a terminal apparatus, such as a user equipment (UE), configured to operate in a connected mode of the RRC, wherein the method comprises receiving (700) at least two sets of configurations for wake-up signal monitoring, wherein a first set of configurations comprises a first search space set for wake-up signal monitoring, and a second set of configurations comprises multiple second search space sets for wake-up signal monitoring; monitoring (702) time elapsed from a transmission of a latest beam report of a serving beam of the apparatus to a network; detecting (704), in response to said time not exceeding a predetermined first threshold, wake-up signals using the first set of configurations; or detecting (706), in response to said time being equal or exceeding the predetermined threshold, wake-up signals using the second set of configurations; and transmitting (708) a beam report of a serving beam of the apparatus to the network.

[0071] Thus, the method enables the UE to be configured with multiple sets of WUS monitoring configurations, where each set may comprise one or more search space sets for monitoring WUS and/or Control Resource Set (CORESET) configurations. The UE determines which set to use at a given time based on the beam measurement reporting status and/or validity regarding the current serving beam. For instance, the UE can be configured with two sets of the WUS monitoring configurations; i.e. a default set 1 and an extended set 2, wherein the use of the extended set 2 may be configured with default UL radio resources that are valid only when/if the set 2 is in use. The UE is also provided with one or more threshold values for the time elapsed since the latest beam measurement reporting, based on which the UE determines which set is in use for WUS monitoring.

Thus, the probability of the UE missing the WUS due to deterioration or failure of the first beam of the UE can be minimized.

[0072] According to an embodiment, the second set of configurations comprises associated uplink radio resources to be used, wherein the beam report of the serving beam of the apparatus is transmitted to the network using the uplink radio resources associated with the second set of configurations. Hence, instead of using the default UL radio resources for transmitting the beam report of the serving beam of the apparatus to the network, the apparatus may receive, along with the second set of configurations, UL radio resources defined be the network. The UE then uses the UL radio resources associated with the second set of configurations for transmitting the beam report of the serving beam of the apparatus to the network.

[0073] The multi -WUS configuration of the UE and the related WUS monitoring are illustrated in Figure 8. The UE is provided with a configuration of at least two sets of search space sets for WUS monitoring: Set 1, which is used by default, comprises a first search space set for WUS monitoring and no implicit beam reporting before / at the onDuration, and Set 2, comprising multiple search space sets for the WUS monitoring as well as uplink radio resources for beam reporting allocated just before the onDuration. [0074] In a default operation, the UE uses Set 1 and monitors only one beam at the determined monitoring occasions (upper monitoring timeline in Figure 8). However, the operation with Set 1 may be subject to a change in beam reporting status, such as the time elapsed since the latest beam measurement reporting extending a threshold value, or an explicit indication from the network to refrain using Set 1. In either case, the UE starts to use Set 2 and monitors a plurality of (in this example three) beams at their determined monitoring occasions (lower monitoring timeline in Figure 8). The UE may assume that the network sends a WUS on one said of said beams. Upon detecting the WUS on one of said beams, the UE uses either the default or the provided uplink radio resources for reporting the preferred beam just before the start of the onDuration. In practise, the UE indicates in the report the beam ID, over which it detected and received the WUS-DCI. If the WUS indicates a wake-up, the UE continues to monitor the indicated beam at the monitoring occasions during the onDuration.

[0075] According to an embodiment, the search space sets of the second set of configurations are associated to same or different Control Resource Sets (CORESETs). [0076] According to an embodiment, a number of CORESETs to which search space sets are associated to depends on a UE capability regarding a number of simultaneous receive panels. Thus, if the monitoring occasions are in the same slot, but not necessarily overlapping, the UE may need to have multiple panels switched on simultaneously to monitor a plurality of beams.

[0077] According to an embodiment, the method further comprises monitoring a number of monitoring occasions since the latest wake-up signalling from the network indicating the apparatus to wake-up, and detecting, in response to said number of monitoring occasions exceeding a predetermined second threshold, wake-up signals using the second set of configurations. Consequently, if the UE has not received WUS indicating the UE to wake up for at least N monitoring occasions (e.g. N-consecutive DRX cycles) where N is configured by the network, the UE assumes that the set 2 is in use. In one example, when the UE has detected a WUS indicating the UE to wake up, it may switch back to use the default set (set 1). [0078] According to an embodiment, the uplink radio resources provided for beam reporting have a fixed time domain relationship to the WUS monitoring occasions in time. For example, the resources may be allocated with n slot/symbols after the last WUS occasion that precedes an onDuration.

[0079] According to an embodiment, the method further comprises receiving an indication from the network to start detecting the wake-up signals using either first set or the second set of configurations. Thus, in some occasions instead of waiting the threshold values to be reached, the network may force the UE to use either of the configuration sets. For example, based on the current PDCCH load and/or past failures event of a UE using the first set, the network may determine to force the UE to use the second set of configuration.

[0080] Alternatively, when network indicates to the UE to enter DRX, it may additionally indicate to the UE to adopt set 1 or set 2 to be used or the UE may be configured to select by default either of the sets. In one option, the default set (set 1 or set 2) is based on the DRX cycle length, where the set 2 would be selected when the cycle length is longer or equal to X milliseconds. Alternatively, one set could be associated to shortDRXcycle configuration and another set to longDRXcycle configuration.

[0081] According to an embodiment, the synchronization signal (SS) set configurations and/or CORESET configurations are a sub-set of configurations used in Active time or separate configurations. In some possible implementations, the Set(s) (selected Set(s) among many or parameters) used for WUS monitoring may be associated to Active time configurations so that applied changes/modifications to Active Time sets would be reflected in WUS monitoring configurations.

[0082] According to an embodiment, the apparatus (UE) is configured to operate in a frequency band of millimeter waves (mmWave) of 3 GPP 5G NR specifications.

[0083] An apparatus according to an aspect of the invention is arranged to implement the method as described above, and possibly one or more of the embodiments related thereto. Thus, the apparatus, such as the apparatus depicted in Figure 1, configured to operate in a connected mode of the RRC and comprising means for receiving at least two sets of configurations for wake-up signal monitoring, wherein a first set of configurations comprises a first search space set for wake-up signal monitoring, and a second set of configurations comprises multiple second search space sets for wake-up signal monitoring; means for monitoring time elapsed from a transmission of a latest beam report of a serving beam of the apparatus to a network; means for detecting, in response to said time not exceeding a predetermined threshold, wake-up signals using the first set of configurations; means for detecting, in response to said time being equal or exceeding the predetermined threshold, wake-up signals using the second set of configurations; and means for transmitting a beam report of a serving beam of the apparatus to the network.

[0084] An apparatus according to a further aspect comprises at least one processor and at least one memory, said at least one memory stored with computer program code thereon, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to operate in a connected mode of the RRC and at least to perform: receive at least two sets of configurations for wake-up signal monitoring, wherein a first set of configurations comprises a first search space set for wake-up signal monitoring, and a second set of configurations comprises multiple second search space sets for wake-up signal monitoring; monitor time elapsed from a transmission of a latest beam report of a serving beam of the apparatus to a network; detect, in response to said time not exceeding a predetermined threshold, wake-up signals using the first set of configurations; or detect, in response to said time being equal or exceeding the predetermined threshold, wake-up signals using the second set of configurations; and transmit a beam report of a serving beam of the apparatus to the network.

[0085] Another aspect relates to the operation of a base station or an access point, such as a gNB, according to the flow chart of Figure 9, wherein the method comprises providing (900) at least one user equipment with at least two sets of configurations for wake-up signal monitoring, wherein a first set of configurations comprises a first search space set for wake-up signal monitoring, and a second set of configurations comprises multiple second search space sets for wake-up signal monitoring; monitoring (902) time elapsed from a reception of a latest beam report of a serving beam of the user equipment; transmitting (904), in response to said time not exceeding a predetermined threshold, wake-up signals to the user equipment using the first set of configurations; or transmitting (906), in response to said time being equal or exceeding the predetermined threshold, wake-up signals to the user equipment using the second set of configurations; and receiving (908) a beam report of a serving beam of the user equipment.

[0086] Hence, at the network side, once a UE is configured with multiple sets of WUS monitoring configurations, the network should keep track of the active set at a given UE. Then the network will transmit the WUS-DCI for the UE on one or more search space set(s) based on the determined set of a UE. Upon receiving the beam indication, i.e. indicating which beam the UE was able to receive the WUS, the network will use it in order to decide which beam to use to scheduling data to the UE during the onDuration. [0087] The method and the embodiments related thereto may be implemented in an apparatus implementing an access point or a base station of a radio access network, such as an eNB or a gNB. The apparatus may comprise at least one processor and at least one memory, said at least one memory stored with computer program code thereon, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: provide at least one user equipment with at least two sets of configurations for wake-up signal monitoring, wherein a first set of configurations comprises a first search space set for wake-up signal monitoring, and a second set of configurations comprises multiple second search space sets for wake-up signal monitoring; monitor time elapsed from a reception of a latest beam report of a serving beam of the user equipment; transmit, in response to said time not exceeding a predetermined threshold, wake-up signals to the user equipment using the first set of configurations; or transmit, in response to said time being equal or exceeding the predetermined threshold, wake-up signals to the user equipment using the second set of configurations; and receive a beam report of a serving beam of the user equipment.

[0088] Such an apparatus may likewise comprise: means for providing at least one user equipment with at least two sets of configurations for wake-up signal monitoring, wherein a first set of configurations comprises a first search space set for wake-up signal monitoring, and a second set of configurations comprises multiple second search space sets for wake-up signal monitoring; means for monitoring time elapsed from a reception of a latest beam report of a serving beam of the user equipment; means for transmitting, in response to said time not exceeding a predetermined threshold, wake-up signals to the user equipment using the first set of configurations; means for transmitting, in response to said time being equal or exceeding the predetermined threshold, wake-up signals to the user equipment using the second set of configurations; and means for receiving a beam report of a serving beam of the user equipment.

[0089] In general, the various embodiments of the invention may be implemented in hardware or special purpose circuits or any combination thereof. While various aspects of the invention may be illustrated and described as block diagrams or using some other pictorial representation, it is well understood that these blocks, apparatus, systems, techniques or methods 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.

[0090] Embodiments of the inventions may be practiced in various components such as integrated circuit modules. The design of integrated circuits is by and large a highly automated process. Complex and powerful software tools are available for converting a logic level design into a semiconductor circuit design ready to be etched and formed on a semiconductor substrate.

[0091] Programs, such as those provided by Synopsys, Inc. of Mountain View, California and Cadence Design, of San Jose, California automatically route conductors and locate components on a semiconductor chip using well established rules of design as well as libraries of pre stored design modules. Once the design for a semiconductor circuit has been completed, the resultant design, in a standardized electronic format (e.g., Opus, GDSII, or the like) may be transmitted to a semiconductor fabrication facility or "fab" for fabrication.

[0092] The foregoing description has provided by way of exemplary and non-limiting examples a full and informative description of the exemplary embodiment of this invention. However, various modifications and adaptations may become apparent to those skilled in the relevant arts in view of the foregoing description, when read in conjunction with the accompanying drawings and the appended examples. However, all such and similar modifications of the teachings of this invention will still fall within the scope of this invention.

Claims

1. An apparatus configured to operate in a connected mode of a radio resource protocol (RRC), the apparatus comprising means for receiving at least two sets of configurations for wake-up signal monitoring, wherein a first set of configurations comprises a first search space set for wake-up signal monitoring, and a second set of configurations comprises multiple second search space sets for wake-up signal monitoring; means for monitoring time elapsed from a transmission of a latest beam report of a serving beam of the apparatus to a network; means for detecting, in response to said time not exceeding a predetermined threshold, wake-up signals using the first set of configurations; means for detecting, in response to said time being equal or exceeding the predetermined threshold, wake-up signals using the second set of configurations; and means for transmitting a beam report of a serving beam of the apparatus to the network.

2. The apparatus according to claim 1, wherein the second set of configurations comprises associated uplink radio resources to be used, and said means for transmitting the beam report of the serving beam of the apparatus to the network is configured to use the uplink radio resources associated with the second set of configurations.

3. The apparatus according to claim 1 or 2, wherein the search space sets of the second set of configurations are associated to same or different Control Resource Sets (CORESETs).

4. The apparatus according to claim 3, wherein a number of CORESETs to which search space sets are associated to depends on a capability of the apparatus regarding a number of simultaneous receive panels.

5. The apparatus according to any preceding claim, further comprising

23 means for monitoring a number of monitoring occasions since the latest wake-up signalling from the network indicating the apparatus to wake-up, and means for detecting, in response to said number of monitoring occasions exceeding a predetermined second threshold, wake-up signals using the second set of configurations.

6. The apparatus according to any preceding claim, wherein the uplink radio resources provided for beam reporting have a fixed time domain relationship to the WUS monitoring occasions in time.

7. The apparatus according to any preceding claim, further comprising means for receiving an indication from the network to start detecting the wakeup signals using either first set or the second set of configurations.

8. The apparatus according to any preceding claim, wherein the apparatus is configured to operate in a frequency band of millimeter waves (mmWave) of 3GPP 5G NR specifications.

9. An apparatus configured to operate in a connected mode of a radio resource protocol (RRC), the apparatus comprising at least one processor and at least one memory, said at least one memory stored with computer program code thereon, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: receive at least two sets of configurations for wake-up signal monitoring, wherein a first set of configurations comprises a first search space set for wake-up signal monitoring, and a second set of configurations comprises multiple second search space sets for wake-up signal monitoring; monitor time elapsed from a transmission of a latest beam report of a serving beam of the apparatus to a network; detect, in response to said time not exceeding a predetermined threshold, wakeup signals using the first set of configurations; or detect, in response to said time being equal or exceeding the predetermined threshold, wake-up signals using the second set of configurations; and transmit a beam report of a serving beam of the apparatus to the network.

10. The apparatus according to claim 9, wherein the second set of configurations comprises associated uplink radio resources to be used, and the apparatus comprises code configured to cause the apparatus to transmit the beam report of the serving beam of the apparatus to the network using the uplink radio resources associated with the second set of configurations.

11. The apparatus according to claim 9 or 10, wherein the search space sets of the second set of configurations are associated to same or different Control Resource Sets (CORESETs).

12. The apparatus according to claim 11, wherein a number of CORESETs to which search space sets are associated to depends on a capability of the apparatus regarding a number of simultaneous receive panels.

13. The apparatus according to any of claims 9 - 12, wherein the apparatus comprises code configured to cause the apparatus to monitor a number of monitoring occasions since the latest wake-up signalling from the network indicating the apparatus to wake-up, and detect, in response to said number of monitoring occasions exceeding a predetermined second threshold, wake-up signals using the second set of configurations.

14. The apparatus according to any of claims 9 - 13, wherein the uplink radio resources provided for beam reporting have a fixed time domain relationship to the WUS monitoring occasions in time.

15. The apparatus according to any of claims 9 - 14, wherein the apparatus comprises code configured to cause the apparatus to receive an indication from the network to start detecting the wake-up signals using either first set or the second set of configurations.

16. The apparatus according to any of claims 9 - 15, wherein the apparatus is configured to operate in a frequency band of millimeter waves (mmWave) of 3 GPP 5GNR specifications.

17. A method comprising: receiving, in an apparatus configured to operate in a connected mode of a radio resource protocol (RRC), at least two sets of configurations for wake-up signal monitoring, wherein a first set of configurations comprises a first search space set for wake-up signal monitoring, and a second set of configurations comprises multiple second search space sets for wake-up signal monitoring; monitoring time elapsed from a transmission of a latest beam report of a serving beam of the apparatus to a network; detecting, in response to said time not exceeding a predetermined threshold, wake-up signals using the first set of configurations; or detecting, in response to said time being equal or exceeding the predetermined threshold, wake-up signals using the second set of configurations; and transmitting a beam report of a serving beam of the apparatus to the network.

18. The method according to claim 17, wherein the second set of configurations comprises associated uplink radio resources to be used, and wherein the beam report of the serving beam of the apparatus is transmitted to the network using the uplink radio resources associated with the second set of configurations.

19. The method according to claim 18 or 19, wherein the search space sets of the second set of configurations are associated to same or different Control Resource Sets (CORESETs).

26

20. The method according to claim 17, wherein a number of CORESETs to which search space sets are associated to depends on a UE capability regarding a number of simultaneous receive panels.

21. The method according to any of claims 17 - 20, the method further comprising monitoring a number of monitoring occasions since the latest wake-up signalling from the network indicating the apparatus to wake-up, and detecting, in response to said number of monitoring occasions exceeding a predetermined second threshold, wake-up signals using the second set of configurations.

22. The method according to any of claims 17 - 21, wherein the uplink radio resources provided for beam reporting have a fixed time domain relationship to the WUS monitoring occasions in time.

23. The method according to any of claims 17 - 22, the method further comprising receiving an indication from the network to start detecting the wake-up signals using either first set or the second set of configurations.

24. The method according to any of claims 17 - 23, wherein the apparatus is configured to operate in a frequency band of millimeter waves (mmWave) of 3 GPP 5GNR specifications.

25. An apparatus comprising means for providing at least one user equipment with at least two sets of configurations for wake-up signal monitoring, wherein a first set of configurations comprises a first search space set for wake-up signal monitoring, and a second set of configurations comprises multiple second search space sets for wake-up signal monitoring; means for monitoring time elapsed from a reception of a latest beam report of a serving beam of the user equipment;

27 means for transmitting, in response to said time not exceeding a predetermined threshold, wake-up signals to the user equipment using the first set of configurations; means for transmitting, in response to said time being equal or exceeding the predetermined threshold, wake-up signals to the user equipment using the second set of configurations; and means for receiving a beam report of a serving beam of the user equipment.

26. An apparatus comprising at least one processor and at least one memory, said at least one memory stored with computer program code thereon, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus at least to perform: provide at least one user equipment with at least two sets of configurations for wake-up signal monitoring, wherein a first set of configurations comprises a first search space set for wake-up signal monitoring, and a second set of configurations comprises multiple second search space sets for wake-up signal monitoring; monitor time elapsed from a reception of a latest beam report of a serving beam of the user equipment; transmit, in response to said time not exceeding a predetermined threshold, wake-up signals to the user equipment using the first set of configurations; or transmit, in response to said time being equal or exceeding the predetermined threshold, wake-up signals to the user equipment using the second set of configurations; and receive a beam report of a serving beam of the user equipment.

27. A method comprising providing at least one user equipment with at least two sets of configurations for wake-up signal monitoring, wherein a first set of configurations comprises a first search space set for wake-up signal monitoring, and a second set of configurations comprises multiple second search space sets for wake-up signal monitoring; monitoring time elapsed from a reception of a latest beam report of a serving beam of the user equipment;

28 transmitting, in response to said time not exceeding a predetermined threshold, wake-up signals to the user equipment using the first set of configurations; or transmitting, in response to said time being equal or exceeding the predetermined threshold, wake-up signals to the user equipment using the second set of configurations; and receiving a beam report of a serving beam of the user equipment.

29