Reference beam reporting

Abstract

Example embodiments of the present disclosure are directed to reference beam reporting. A method comprises determining that at least one condition for a trigger event is satisfied; selecting, according to a specified criterion, one or more reference beams to be reported in a beam report, from at least one reference beam that is involved in satisfaction of the at least one condition for the trigger event; and transmitting, to a network device, the beam report comprising an indication of the one or more reference beams.

Description

REFERENCE BEAM REPORTINGFIELD

[0001] 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 reference beam reporting.BACKGROUND

[0002] A communication network may serve as a facility that enables communications between two or more communication devices or provides communication devices access to a data network. A mobile or wireless communication network is one example of a communication network. The communication network may operate in accordance with standards such as those provided by Third Generation Partnership Project (3 GPP) or European Telecommunications Standards Institute (ETSI). Examples of standards provided by 3GPP are the so-called 3GPP standards for cellular technology generations, such as 3GPP standards for 4G technology, 5G technology, 6G technology etc.SUMMARY

[0003] In a first aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to: determine that at least one condition for a trigger event is satisfied; select, according to a specified criterion, one or more reference beams to be reported in a beam report, from at least one reference beam that is involved in satisfaction of the at least one condition for the trigger event; and transmit, to a network device, the beam report comprising an indication of the one or more reference beams.

[0004] In a second aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus at least to: receive, from a terminal device, a beam report comprising an indication of one or more reference beams selected from at least one reference beam that is involved in satisfaction of at least one condition for a trigger event; and determine occurrence of the one or more reference beams with respect to a configured time window based on acriterion specified for the terminal device, wherein the configured time window is configured for the terminal device to determine whether the at least one condition for the trigger event is satisfied.

[0005] In a third aspect of the present disclosure, there is provided a method. The method comprises: determining that at least one condition for a trigger event is satisfied; selecting, according to a specified criterion, one or more reference beams to be reported in a beam report, from at least one reference beam that is involved in satisfaction of the at least one condition for the trigger event; and transmitting, to a network device, the beam report comprising an indication of the one or more reference beams.

[0006] In a fourth aspect of the present disclosure, there is provided a method. The method comprises: receiving, from a terminal device, a beam report comprising an indication of one or more reference beams selected from at least one reference beam that is involved in satisfaction of at least one condition for a trigger event; and determining occurrence of the one or more reference beams with respect to a configured time window based on a criterion specified for the terminal device, wherein the configured time window is configured for the terminal device to determine whether the at least one condition for the trigger event is satisfied.

[0007] In a fifth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for determining that at least one condition for a trigger event is satisfied; means for selecting, according to a specified criterion, one or more reference beams to be reported in a beam report, from at least one reference beam that is involved in satisfaction of the at least one condition for the trigger event; and means for transmitting, to a network device, the beam report comprising an indication of the one or more reference beams.

[0008] In a sixth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises means for receiving, from a terminal device, a beam report comprising an indication of one or more reference beams selected from at least one reference beam that is involved in satisfaction of at least one condition for a trigger event; and means for determining occurrence of the one or more reference beams with respect to a configured time window based on a criterion specified for the terminal device, wherein the configured time window is configured for the terminal device to determine whether the at least one condition for the trigger event is satisfied.

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

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

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

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

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

[0014] FIG. 2A illustrates a schematic diagram of example TCI state configurations;

[0015] FIG. 2B illustrates a schematic diagram of further example TCI state configurations;

[0016] FIG. 3 is a schematic diagram illustrating change of reference beam within the configured time window for an event-7;

[0017] FIG. 4 illustrates an example signaling flow for reference beam reporting based on a specified criterion in accordance with some example embodiments of the present disclosure;

[0018] FIG. 5 illustrates an example signaling flow for reference beam reporting based on a latest measured reference beam at the time of the first uplink transmission towards the network device in accordance with some example embodiments of the present disclosure;

[0019] FIG. 6 illustrates an example signaling flow for reference beam reporting based on a latest measured reference beam at a time of transmission of a beam report in accordance with some example embodiments of the present disclosure

[0020] FIG. 7A illustrates a schematic diagram of selection of a latest measured reference beam at the end of the configured time window to be reported in the beam report in accordance with some example embodiments of the present disclosure;

[0021] FIG. 7B illustrates a schematic diagram of selection of the latest measured reference beam at the time of the first PUCCH transmission in accordance with some example embodiments of the present disclosure;

[0022] FIG. 7C illustrates a schematic diagram of selection of the latest measured reference beam at the time of the actual transmission of the beam report in accordance with some example embodiments of the present disclosure;

[0023] FIG. 8 illustrates a signaling flow for reference beam reporting in accordance with some example embodiments of the present disclosure;

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

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

[0026] FIG. 10A illustrates a flowchart of a method implemented at a first apparatus in accordance with some example embodiments of the present disclosure;

[0027] FIG. 10B illustrates a flowchart of a method implemented at a second apparatus in accordance with some example embodiments of the present disclosure;

[0028] FIG. 11A illustrates a flowchart of a method implemented at a first apparatus in accordance with some example embodiments of the present disclosure;

[0029] FIG. 11B illustrates a flowchart of a method implemented at a second apparatus in accordance with some example embodiments of the present disclosure;

[0030] FIG. 12 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

[0031] FIG. 13 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

[0032] Throughout the drawings, the same or similar reference numerals represent the same or similar element.DETAILED DESCRIPTION

[0033] 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.

[0034] 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.

[0035] 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.

[0036] It shall be understood that although the terms “first,” “second,”..., etc. in front of noun(s) and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another and they do not limit the order of the noun(s). For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0037] 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.

[0038] As used herein, unless stated explicitly, performing a step “in response to A” doesnot indicate that the step is performed immediately after “A” occurs and one or more intervening steps may be included.

[0039] 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.

[0040] 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.

[0041] 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 processorintegrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0042] As used herein, the term “communication network” refers to a network following any suitable communication standards, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G), the second generation (2G), 2.5G, 2.75G, the third generation (3G), the fourth generation (4G), 4.5G, the fifth generation (5G), 5.5G, the sixth generation (6G) communication protocols, and / or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

[0043] As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, an Integrated Access and Backhaul (IAB) node, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, a transmission and reception point (TRP), 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.

[0044] 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 mayalso 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.

[0045] As used herein, the term “resource,” “transmission resource,” “resource block,” “physical resource block” (PRB), “uplink resource,” or “downlink resource” may refer to any resource for performing a communication, for example, a communication between a terminal device and a network device, such as a resource in time domain, a resource in frequency domain, a resource in space domain, a resource in code domain, or any other combination of the time, frequency, space and / or code domain resource enabling a communication, and the like. In the following, unless explicitly stated, a resource in both frequency domain and time domain will be used as an example of a transmission resource for describing some example embodiments of the present disclosure. It is noted that example embodiments of the present disclosure are equally applicable to other resources in other domains.

[0046] FIG. 1 illustrates a schematic diagram of an example communication environment 100 in which example embodiments of the present disclosure can be implemented. In the communication environment 100, a plurality of communication devices, including a terminal device 110 and a network device 120, may communicate with each other.

[0047] In the example of FIG. 1, the terminal device 110 may be a UE and the network device 120 may be a base station serving the UE. The network device 120 operates in a radio access network (RAN) and thus is also referred to as a RAN network device.

[0048] 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 implement example embodiments of the present disclosure. It is noted that although illustrated as a network device, the network device 120 may be another device than a network device. Although illustrated as a terminal device, the terminal device 110 may be another device than a terminal device.

[0049] In the following, for the purpose of illustration, some example embodiments are described with a terminal device 110 operating as a UE and a network device 120 operating as a base station, e.g., gNB. However, in some example embodiments, operations described in connection with a terminal device may be implemented at a network device or other device, and operations described in connection with a network device may be implemented at a terminal device or other device.

[0050] In some example embodiments, a communication direction from the network device 120 to the terminal device 110 is referred to as a downlink (DL), while a communication direction from the terminal device 110 to the network device 120 is referred to as an uplink (UL). In DL, the network device 120 is a transmitting (TX) device (or a transmitter) and the terminal device 110 is a receiving (RX) device (or a receiver). In UL, the terminal device 110 is a TX device (or a transmitter) and the network device 120 is an RX device (or a receiver).

[0051] 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 spreadOFDM (DFT-s-OFDM) and / or any other technologies currently known or to be developed in the future.

[0052] Some use cases where a UE could benefit from initiating the beam management reporting have been identified (e.g., to facilitate beam switch). The UE-initiated (UEI) beam management (UEIBM) feature is defined as the case where the UE may be configured with at least one event or condition, and then the UE may start beam reporting if the at least one event or condition occurs or is satisfied. The beam report may be transmitted by the UE only when needed, thereby avoiding unnecessary beam reports caused by periodic reporting with small periodicities and reducing the overhead. Moreover, the beam report may be transmitted upon the fulfilment of certain events or conditions, thereby avoiding long delays associated with periodic reporting configured with large periodicities and reducing latency.

[0053] Enhancements have been specified to facilitate UEI or event-driven beam management for the reduction of overhead and / or latency, assuming the unified transmission configuration indicator (TCI), while legacy channel state information (CSI) measurement and reporting configuration frameworks are leveraged, targeting frequency range 2 (FR2) and single transmission and reception point (sTRP) with intra-cell beam management and inter-cell beam management. The UL signaling content (and procedures as required) for UEI or event-driven beam reporting facilitates fast beam switching. The UL signaling medium or container is designed primarily for the purpose of beam reporting, considering the UEI or event-driven nature of the UL transmission.

[0054] The “unified” TCI framework has been introduced, meaning that TCI states providing quasi co-location (QCL) assumptions for the reception of DL signals and channels may be used to provide spatial sources for the transmission of UL signals and channels to determine UL TX spatial filter.

[0055] There is a pool of TCI states configured via radio resource control (RRC), and such TCI states may also be called “configured TCI states”. A subset of these configured TCI states may be activated via media access control control element (MAC CE) with up to 8 TCI codepoints, each codepoint pointing to joint DL or UL TCI states or separate DL TCI states or separate UL TCI states. Such TCI states may also be called “activated TCI states”.

[0056] The unified TCI framework also defines the concept of “indicated TCI states”,which may be joint DL or UL TCI states or separate DL and separate UL TCI states. That means that one or multiple (in case of multi-TRP for instance) of the configured TCI states may be indicated TCI state(s) at a time. The unified TCI framework for sTRP has been introduced. FIG. 2A illustrates a schematic diagram 200A of example TCI state configurations. As illustrated in FIG. 2A, one joint DL or UL TCI state may be indicated at a time, or one separate DL and one separate UL TCI state may be indicated at a time for the UE. The unified TCI framework for multi-TRP (mTRP) has been extended. FIG.2B illustrates a schematic diagram 200B of further example TCI state configurations. As illustrated in FIG. 2B, up to two joint TCI states may be indicated at a time, or up to two separate DL and up to two separate UL TCI states may be indicated at a time for the UE.

[0057] In some embodiments, three events have been defined which may trigger a beam report (e.g., the UEIBM report). The three events include an event-2, an event-1 and an event-7. The event-2 may occur when the quality of at least one new beam (such as its layer 1 reference signal received power (Ll-RSRP)) becomes a certain “threshold value” better than that of the current beam. For example, the network may configure the UE with a certain threshold (e.g., 3 dB). When the UE measures a new beam with an Ll-RSRP that is 3 dB better than the Ll-RSRP of the current beam, then a UEIBM report is triggered. The event- 1 may occur when the quality of the current beam is worse than a certain threshold. The event- 1 may be used to avoid costly procedures like beam failure recovery (BFR). The event-7 may occur when the quality (such as Ll-RSRP) of at least one new beam becomes a threshold value better than the reference signal (RS) derived from the activated TCI state with the Q-th best quality. Q may be a RRC configured value with subjective to UE capability signalling. The event-7 may be used to update the active TCI state list.

[0058] In the context of triggering event determination for the event-2, two options have been defined. The first option is the basic functionality, once the Ll-RSRP of the new beam becomes a threshold value better than the current beam, UEI beam report occurs. The second option is subject to UE capability. If within a time window (which is configurable), the number of event-2 instance(s) for at least one same new beam is greater than or equal to a configurable number M, the UEI beam report occurs.

[0059] There may be two procedures for sending these beam reports by the UE to the network, including Mode A and Mode B. In Mode A, the second UL channel for the UEI report may be dynamically scheduled by the gNB. The UE may send an UL indication inthe first physical uplink control channel (PUCCH) channel to request resources from the gNB for a second UL channel to carry the UEI report. The gNB may indicate via downlink control information (DCI) to the UE a resource in a second UL channel to carry the UEI report, and the UE may then send the UEI report on the second UL channel. In Mode B, the second UL channel for the UEI report may be pre-configured by the gNB. The UE may send an UL indication in the first PUCCH channel to notify the gNB that a UEI report will be transmitted in a second UL channel, and the UE may then send the UEI report on the second UL channel. The Mode A may be the baseline and may be supported by all UEs capable of UEIBM, while Mode B may be optional and may be supported only by some UEs.

[0060] In the context of what to report, i.e., the UL signal content of the UEIBM report for event-2 with Ll-RSRP as quality metric, it has been agreed that the UE reports N beams, for example the top N beams, with N>1 configured by the network via RRC, and at least one of those N beams satisfies the event-2. Then, in addition to those N beams, the network may configure via RRC the UE to also report the current beam.

[0061] In the context of which RSs should be monitored or measured for current and new beams by the UE for the event-2, the UE may be supposed to monitor the current beam and a certain number of new beams (note that “new” beams are sometimes referred to as well as “candidate beams” or “candidate new beams”). For example, the RS(s) for the new beam(s) may be explicitly configured by the network via RRC and may be either a set of synchronization signal blocks (SSBs) or a set of channel state information-reference signals (CSI-RSs). The RS for the current beam may be related to the indicated TCI state, with an implicit method such that the current beam may be either the actual RS in the indicated TCI state or the SSB which is quasi co-located (QCLed) with the actual RS in the indicated TCI state. This may depend on the configured set of new beams, to make sure that current and new beams are of the same “type,”, e.g., either all SSBs or all CSI-RSs.

[0062] For the event-7, an issue is how to actually select the RS for the beam derived from the activated TCI state with the Q-th best quality, which is referred to as a reference beam. Some method for the event-2 may be adopted. For example, for the event-7, the scheme- 1 and scheme-2 for deriving ‘RS for current beam’ on the event-2 may be reused. In scheme-1, the ‘RS for current beam’ is the QCL RS in the activated TCI state with the Q-th best quality. In scheme-2, the ‘RS for current beam’ is the SSB which is QCLed withthe QCL RS in the activated TCI state with the Q-th best quality. The basic feature of the triggering event determination for the event-7 may include that once the quality of at least one new beam becomes a threshold value better than the RS derived from the activated TCI state with the Q-th best quality, the UE initiated beam report occurs. It is noted that for the event-2, in the scheme-1, the RS for current beam is the QCL RS in the indicated TCI state, whereas in the scheme-2, the RS for current beam is the SSB which is QCLed with the QCL RS in the indicated TCI state.

[0063] In case the time window and counter are configured, the reference beam of the event-7 may change during the time window. FIG. 3 is a schematic diagram 300 illustrating change of reference beam within the configured time window for the event-7. As illustrated in FIG. 3, the event-7 is configured with Q=2, and there are three active TCI states for a UE, including the indicated TCI state TCI#1, the activated TCI state TCI#2, and the activated TCI state TCI#3. Within the first part of the configured time window 301, TCI#3 is the activated TCI with the second (Q=2) best quality among the three activated TCI states, thus TCI#3 is the reference beam. Within the second part of the configured time window 303, TCI#2 is the activated TCI with the second (Q=2) best quality among the three activated TCI states, thus TCI#2 is the reference beam. In other words, within the whole configured time window, there are two reference beams. The reference beam of the event-7 changes within the whole configured time window.

[0064] Unlike the event-2, where the current beam is uniquely identified by the indicated TCI state as a reference beam, the event-7 may not have such a unique identification for the “reference beam”. Therefore, for the event-7, a related issue not yet solved is about which reference beam needs to be reported by the UE when the event-7 is triggered. As an example, similar to the beam report of the event-2, N new beams may be reported, with N configured by the network. Alternately, the reference beam (instead of the current beam) may be reported, if the network configures the UE to report that via RRC. On the other hand, a further issue lies in that, in case the reference beam changes within the time window, which reference beam may be included in the actual beam report. Note that the issue arises also because the event-7 may be triggered by measurements that assume different or multiple reference beams within the time window (as illustrated in FIG. 1), but only one will be the reference beam reported by the UE.

[0065] In accordance with some example embodiments of the present disclosure, there is provided some solutions to identify the reference beam to be included in the beam reportwhen a time window is configured for determination of the occurrence of a trigger event. This may be important when the index of the reference beam changes either within the configured time window or after the triggering of the event-7 but before the time of the actual transmission of the beam report. In a solution, if a device, e.g., a terminal device determines that at least one condition for a trigger event is satisfied, the terminal device selects, according to a specified criterion, one or more reference beams to be reported in a beam report, from at least one reference beam that is involved in satisfaction of the at least one condition for the trigger event, and then transmits, to a network device, the beam report including an indication of the one or more reference beams. In this way, the terminal device may report the most recent or fresh information about the reference beam to the network device. The network device may have less outdated information to take any further action, for example on beam switching or on active TCI state list update.

[0066] Example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0067] FIG. 4 illustrates an example signaling flow 400 for reference beam reporting based on a specified criterion in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the signaling flow 400 will be discussed with reference to FIG. 1. As shown in FIG. 4, the signaling flow 400 involves the terminal device 110, and the network device 120. In some example embodiments, the terminal device 110 may be or may be included in a UE. The network device 120 may include a gNB.

[0068] The network device 120 may transmit (401) configuration associated with a trigger event for beam reporting. The terminal device 110 may receive (403) the configuration from the network device 120. In some example embodiments, the configuration associated with the trigger event may include corresponding information that defines at least one condition under which the trigger event occurs and how the terminal device 110 reports. The configuration associated with the trigger event may further indicate a configured time window during which the at least one condition of the trigger event is evaluated to determine whether one or more conditions are satisfied.

[0069] The trigger event is an event defined to trigger a beam report based on measurements of reference signals on respective beams. In some examples, the trigger event may include the event-7. The event-7 may occur when the quality (such as Ll-RSRP)of at least one new beam becomes a threshold value better than the RS derived from the activated TCI state with the Q-th best quality. For the event-7, a reference beam is corresponding to the RS derived from the activated TCI state with the Q-th best quality. For example, if the value of Q is configured as 2, then a reference beam is determined as a beam corresponding to an activated TCI state that is measured to have the second best quality. In addition to the event-7, there may be other trigger events whose reference beam is not uniquely identified. The example embodiments may be similarly applied to those trigger events.

[0070] Based on the received configuration, the terminal device 110 may measure beams associated with the active TCI states, and possible new beams, to determine whether the at least one condition for the trigger event is satisfied. Specially, the network device 120 may transmit DL RSs on the beams and the terminal device 110 may measure the DL RSs on the beams.

[0071] Based on the measurement on the beams, the terminal device 110 determines (405) that the at least one condition for the trigger event is satisfied. The terminal device 110 may then determine to report this situation to the network device 120.

[0072] In some cases, the terminal device 110 may determine that at least one reference beam may be used or involved in the determination that at least one condition for the trigger event is satisfied. For example, the at least one condition may include that the quality of at least one new beam becomes a threshold value better than a reference beam measured to satisfy a configured quality in an activated TCI state among a plurality of activated TCI states. The at least one reference beam may include characteristics such as being measured to satisfy the configured quality, or being in the activated TCI state. As an example, the at least one condition may include that the quality (such as Ll-RSRP) of at least one new beam becomes a threshold value better than the reference beam derived from the activated TCI state with the Q-th best quality. In some examples, Q may be configured by the network device 120. For example, Q may be 2 or any other value. If a beam is measured to be the Q-th best quality among all the beams for the active TCI states, then it may be determined to satisfy the configured quality and thus may be selected as a reference beam. Then if a new beam is measured to have a quality that is a threshold value better than the quality of the reference beam, than the at least one condition of the trigger event is satisfied, and the terminal device 110 may trigger beam reporting with the network device.

[0073] As the reference beam is the beam with the Q-th best quality, among all the beams, it is possible that the reference beam may change over time. Thus, the terminal device 110 may determine that at least one reference beam may be used or involved in the determination that at least one condition for the trigger event is satisfied.

[0074] Then if the at least one condition for the trigger event is satisfied and the beam reporting is triggered, the terminal device 110 then selects (407), according to a specified criterion, one or more reference beams to be reported in a beam report, from at least one reference beam that is involved in satisfaction of the at least one condition for the trigger event. In some example embodiments, the specified criterion may be used to indicate the terminal device 110 to select the specific reference beam to be included in the beam report.

[0075] In some example embodiments, the determination of whether the at least one condition for the trigger event is satisfied may involve a configured time window (also referred to as the configured time window for trigger event determination). The configured time window may define a specific duration or period during which certain conditions are expected to be satisfied to potentially trigger a particular action, e.g., the transmission of the beam report. For example, the configured time window may serve to ensure that the transmission of the beam report is triggered only when at least one condition is satisfied over the specified duration or period, thus preventing unnecessary reporting that may occur due to transient or incidental condition satisfaction. For instance, if the terminal device 110 detects that at least one condition for the trigger event is satisfied within the configured time window, the terminal device 110 may decide to initiate the beam report. In the present disclosure, the configured time window may be sliding or fixed with respect to the transmission of the first PUCCH, but it would be appreciated that the present disclosure does not limit it thereto.

[0076] In some example embodiments, the specified criterion applied in selecting the reference beam(s) to be reported may be determined based on the configured time window. In some example embodiments, depending on the specified criterion, the selected one or more reference beams to be reported in the beam report may include a latest measured reference beam at an end of the configured time window. Alternatively, the selected one or more reference beams to be reported in the beam report may include a latest measured reference beam at the beginning of the configured time window. For example, if more than one reference beam is determined within the configured time window, the terminal device 110 may select the latest measured reference beam at the beginning or the end ofthe configured time window. FIG. 7A illustrates a schematic diagram 700A of selection of a latest measured reference beam at the end of the configured time window to be reported in the beam report in accordance with some example embodiments of the present disclosure.

[0077] In the schematic diagram 700A, it is assumed that the terminal device 110 have 3 active TCI states, with TCI#1 being the indicated TCI state and the best in terms of Ll-RSRP, TCI#2 being the activated TCI state, and TCI#3 being another activated TCI state. The terminal device 110 is configured with the trigger event, e.g., the event-7, Q=2. For simplicity, a set of new beams to be monitored is composed of a single new beam. The event-7 may be triggered, if, within the configured time window, the new beam is M (configured by the network device 120) times a threshold value better than the beam associated to the second (as Q=2) best activated TCI state.

[0078] Within the configured time window, the reference beam corresponding to the TCI#3 is assumed to be the reference beam to be considered for trigger event determination, as the Ll-RSRP of TCI#3 is better than Ll-RSRP of TCI#2. That is, the TCI#3 is the TCI state with the Q-th best quality. However, the Ll-RSRP of TCI#3 degrades while Ll-RSRP of TCI#2 improves over time outside of the configured time window. In particular, the Ll-RSRP of TCI#2 is better than Ll-RSRP of TCI#3 at both the times of first PUCCH and PUSCH for beam reporting.

[0079] In this scenario, the terminal device 110 may have multiple options to select which reference beam to be included in the beam report. For example, as illustrated in FIG. 7 A, the terminal device 110 may still select the latest measured reference beam at the end of the configured time window, i.e., the reference beam corresponding to the TCI#3.

[0080] Alternatively, in some example embodiments, the at least one reference beam is measured within the configured time window. The selected one or more reference beams to be reported in the beam report may include a reference beam with a highest signal quality within the configured time window. For example, the terminal device 110 may measure at least one reference beam within the configured time window. The terminal device 110 may select, from the at least one reference beam, the reference beam with the best or highest Ll-RSRP measured within the configured time window to be included in the beam report.

[0081] Alternatively, in some example embodiments, the selected one or more reference beams to be reported in the beam report may include a reference beam with the greatest number of measurement times within the configured time window. For example, the terminal device 110 may measure at least one reference beam within the configured time window. The terminal device 110 may select, from the at least one reference beam, the reference beam that is mostly evaluated or measured among all reference beams within the configured time window to be included in the beam report. If more than one reference beam that occupies the same period of time within the configured time window. The selected one or more reference beams to be reported in the beam report may include the latest measured reference beam at the end of the configured time window. For example, if there is more than one reference beam that has occupied that same most of the time within the configured time window, the terminal device 110 may select the latest measured reference beam at the end of the configured time window to be included in the beam report.

[0082] Alternatively, in some example embodiments, if a reference beam remains unchanged within the configured time window, the selected one or more reference beams to be reported in the beam report may include the reference beam. For example, if the index of the reference beam does not change within the configured time window, the terminal device 110 may select this reference beam to be included in the beam report.

[0083] In some example embodiments, the specified criterion may be determined based on reception of at least one downlink reference signal from the network device 120. The selected one or more reference beams to be reported in the beam report may include a reference beam associated with the latest reception of a downlink reference signal. For example, the reference beam may relate to the latest DL RS transmission. For example, if the DL RSs may be SSBs with e.g. 40 or 80 ms periodicity, the transmission of the DL RS may be before the first PUCCH transmission, or it may be between the first PUCCH and the PUSCH (i.e., the second UL channel) transmission. Then, the time of the latest DL RS transmission may be used to determine the reference beam to be included in the beam report, rather than the time of an UL transmission. It is assumed that the terminal device 110 measures all the occasions of the DL RS in order to give the most accurate report. This may be applicable to the tracking reference signal (TRS) (with a periodicity from 10 to 80 slots) and to the CSI-RS (with a periodicity varying from 4 to 480 slots).

[0084] The terminal device 110 transmits (409) the beam report to the network device 120. The beam report includes an indication of the one or more reference beams. Thenetwork device 120 receives (411) the beam report from a terminal device. For example, the network device 120 may transmit an uplink resource scheduled for transmission of the beam report to the terminal device 110. The terminal device 110 may receive the uplink resource, and transmit the beam report to the network device 120 by using the uplink resource. The network device 120 may receive the beam report from the terminal device on the uplink resource. The beam report may further include at least one indication of at least one beam that is measured to be with a threshold value better than the at least one reference beam.

[0085] In some example embodiments, there may be a plurality of reference beams to be determined. The terminal device 110 may transmit an indication of the number of reference beams to the network device 120. For example, the indication of the number of reference beams may be included in the beam report. Alternatively, the terminal device 110 may transmit the indication separately.

[0086] In some example embodiments, it may be up to the network device 120 to decide how many reference beams are reported by the terminal device 110 by scheduling a proper uplink resource. The terminal device 110 may determine whether the uplink resource is available for transmission of the beam report with one or more reference beams. If the terminal device 110 determines that uplink resource is available for transmission of the beam report with one reference beam, the terminal device 110 may transmit the beam report including the indication of the one reference beam selected from the at least one reference beam to the network device 120. If the terminal device 110 determines that uplink resource is available for transmission of the beam report with a plurality of reference beams, the terminal device 110 may transmit the beam report at least including respective indications of the plurality of reference beams to the network device 120. For example, the terminal device 110 may report to the network device 120 that three reference beams have been determined. The network device 120 may ask the terminal device 110 to report just one reference beam. In this case, the terminal device 110 may transmit the beam report including one reference beam. Alternatively, the network device 120 may ask the terminal device 110 to report all of the three reference beams. The terminal device 110 may then transmit the beam report including the three reference beams.

[0087] In some example embodiments, the specified criterion may be configured by the network device 120. For example, the network device 120 may transmit signaling indicating a specified criterion to the terminal device 110, e.g., via RRC or MAC CE. Forexample, there may be a set of pre-defined rules for the specified criterion. For example, one rule considering the time of the beam report transmission, another rule considering the time of the first PUCCH transmission, and another rule considering the end of the configured time window, and so on. The network device 120 may then configure via RRC the terminal device 110 to use one of such rules. Such rules may allow the network device 120 to have the flexibility to either configure different terminal devices differently or configure the same terminal device differently over time.

[0088] In some example embodiments, alternatively, the specified criterion may be prespecified or fixed at the terminal device 110. For example, the terminal device 110 may indicate to the network device 120 the conditions or parametrization under which the reference beam has changed within the configured time window. The indication may further include how many reference beams are embedded in the first PUCCH. In such scenario, in response to such indication, the network device 120 may allocate corresponding resources for the beam report to include more than one reference beam to be reported on the physical uplink shared channel (PUSCH).

[0089] In some example embodiments, the time of the beam report transmission may allow to capture potential variations of the index of the reference beam even after the end of the configured time window. The specified criterion may be determined based on a first uplink transmission towards the network device 120. FIG. 5 illustrates an example signaling flow 500 for reference beam reporting based on a latest measured reference beam at the time of the first uplink transmission towards the network device in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the signaling flow 500 will be discussed with reference to FIG. 1. As shown in FIG. 5, the signaling flow 500 involves the terminal device 110, and the network device 120.

[0090] The network device 120 may transmit (501) configuration associated with a trigger event for beam reporting. The terminal device 110 may receive (503) the configuration from the network device 120. The terminal device 110 determines (505) that at least one condition for the trigger event is satisfied. The steps 501, 503 and 505 may be similar to the steps 401, 403 and 405 in FIG. 4. For details, reference may be made to the above description, which will not be repeated here.

[0091] In some cases, the terminal device 110 may determine that at least one reference beam may be used or involved in the determination that at least one condition for thetrigger event is satisfied. The network device 120 may transmit signaling indicating a specified criterion for selecting the corresponding reference beam to the terminal device 110. For example, the network device 120 may transmit, to the terminal device 110, signaling indicating the specified criterion for selecting the latest measured reference beam at the time of the first uplink transmission for beam reporting. The terminal device 110 may receive the signaling from the network device 120. The terminal device 110 then selects (507), from the at least one reference beam that is involved in satisfaction of the at least one condition for the trigger event, the latest measured reference beam at the time of the first uplink transmission towards the network device 120.

[0092] In some example embodiments, the determination of whether the at least one condition for the trigger event is satisfied may involve a configured time window. The first uplink transmission may include a first uplink transmission outside of the configured time window. For example, the first uplink transmission may include a first uplink transmission after the end of the configured time window. The first uplink transmission may include a first transmission of uplink control information. The uplink control information may include PUCCH. For example, the terminal device 110 selects the latest measured reference beam at the time of first PUCCH transmission by the terminal device 110.

[0093] FIG. 7B illustrates a schematic diagram 700B of selection of the latest measured reference beam at the time of the first PUCCH transmission in accordance with some example embodiments of the present disclosure. The example of FIG. 7B is illustrated with the same assumption as in the example of FIG. 7A. Different from the example of FIG. 7A where the terminal device 110 selects the latest measured reference beam at the end of the configured time window, i.e., the reference beam corresponding to TCI#3, in FIG. 7B, the terminal device 110 may select the latest measured reference beam at the time of the first PUCCH transmission, which is the reference beam corresponding to the TCI#2.

[0094] The terminal device 110 transmits (509) a beam report including an indication of the latest measured reference beam at the time of the first uplink transmission towards the network device to the network device 120. In some example embodiments, the beam report may further include at least one indication of at least one beam that is measured to be with a threshold value better than the at least one reference beam. The network device 120 receives (511) the beam report from a terminal device.

[0095] In some example embodiments, there may be a plurality of reference beams to be determined. The terminal device 110 may transmit an indication of the number of reference beams to the network device 120. The terminal device 110 determines whether the uplink resource is available for transmission of the beam report with one or more reference beams. If the terminal device 110 determines that uplink resource is available for transmission of the beam report with one reference beam, the terminal device 110 may transmit the beam report including the indication of the latest measured reference beam at the time of the first uplink transmission towards the network device. If the terminal device 110 determines that uplink resource is available for transmission of the beam report with a plurality of reference beams, the terminal device 110 may transmit the beam report at least including respective indications of the plurality of reference beams to the network device 120.

[0096] In some example embodiments, the specified criterion may be determined based on a transmission occasion of the beam report. FIG. 6 illustrates an example signaling flow 600 for reference beam reporting based on a latest measured reference beam at a time of transmission of a beam report in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the signaling flow 600 will be discussed with reference to FIG. 1. As shown in FIG. 6, the signaling flow 600 involves the terminal device 110, and the network device 120.

[0097] The network device 120 may transmit (601) configuration associated with a trigger event for beam reporting. The terminal device 110 may receive (603) the configuration from the network device 120. The terminal device 110 determines (605) that at least one condition for the trigger event is satisfied. The steps 601, 603 and 605 may be similar to the steps 401, 403 and 405 in FIG. 4. For details, reference may be made to the above description, which will not be repeated here.

[0098] In some cases, the terminal device 110 may determine that at least one reference beam may be used or involved in the determination that at least one condition for the trigger event is satisfied. In some example embodiments, the network device 120 may transmit signaling indicating a specified criterion of selecting the latest measured reference beam at the time of the transmission of the beam report for beam reporting to the terminal device 110. The terminal device 110 may select the latest measured reference beam for the beam report by applying the specified criterion. The terminal device 110 selects (607), from at least one reference beam that is involved in satisfaction of the atleast one condition for the trigger event, a latest measured reference beam at a time of transmission of a beam report. In some example embodiments, the determination of whether the at least one condition for the trigger event is satisfied may involve a configured time window. The time of transmission of the beam report may be after the end of the configured time window. For example, the terminal device 110 may select the latest measured reference beam at the time of transmission of the beam report after the end of the configured time window.

[0099] The terminal device 110 transmits (609) a beam report including an indication of the latest measured reference beam at the time of the transmission of the beam report to the network device 120. In some example embodiments, the beam report may further include at least one indication of at least one beam that is measured to be with a threshold value better than the at least one reference beam. In some example embodiments, the transmission of a beam report may be carried in the PUSCH. The network device 120 receives (611) the beam report from the terminal device 110.

[0100] In some example embodiments, the time of the transmission of the beam report is scheduled by the network device. For example, the time at which the terminal device 110 transmits the beam report on the PUSCH scheduled by the network device 120. The terminal device 110 may transmit a request for transmitting the beam report to the network device 120. The network device 120 may transmit scheduling information of the resource for the beam report to the terminal device 110. The terminal device 110 may receive the scheduling information, and transmit the beam report to the network device by using the resource. For example, the terminal device 110 may select the latest measured reference beam at the time at which the terminal device 110 transmits the beam report on the PUSCH.

[0101] FIG. 7C illustrates a schematic diagram 700C of selection of the latest measured reference beam at the time of the actual transmission of the beam report in accordance with some example embodiments of the present disclosure. The example of FIG. 7B is illustrated with the same assumption as in the example of FIG. 7 A and FIG. 7B. However, in the example of FIG. 7C, the terminal device 110 may select the latest measured reference beam at the time of the actual transmission of the beam report, which is the reference beam corresponding to the TCI#2.

[0102] In some example embodiments, the time of the transmission of the beam report may be a time of a pre-configured resource of the terminal device 110. The terminal device110 may transmit an indication indicative of transmission of the beam report to the network device, and then transmit the beam report using the pre-configured resource to the network device. For example, the pre-configured resource may include configured grant. For example, the terminal device 110 may select the latest measured reference beam at the time at which the terminal device 110 transmits the beam report in the CG-PUSCH.

[0103] In some example embodiments, there may be a plurality of reference beams to be determined. The terminal device 110 may transmit an indication of the number of reference beams to the network device 120. The terminal device 110 determines whether the uplink resource is available for transmission of the beam report with one or more reference beams. If the terminal device 110 determines that uplink resource is available for transmission of the beam report with one reference beam, the terminal device 110 may transmit the beam report including the indication of the latest measured reference beam at the time of the transmission of the beam report. If the terminal device 110 determines that uplink resource is available for transmission of the beam report with a plurality of reference beams, the terminal device 110 may transmit the beam report at least including respective indications of the plurality of reference beams to the network device 120.

[0104] FIG. 8 illustrates a signaling flow 800 for reference beam reporting in accordance with some example embodiments of the present disclosure. As shown in FIG. 8, the signaling flow 800 involves a UE 810 and a gNB 820. The UE 810 may be an example of the terminal device 110 in FIG. 1. The gNB 820 may be an example of the network device 120 in FIG. 1. The signaling flow 800 may be an example of the signaling flow 400, the signaling flow 500, or the signaling flow 600.

[0105] In the signaling flow 800, the UE 810 is configured (801) with the event-7 for beam reporting. At 803, the gNB 820 transmits DL RS(s) to the UE 810.

[0106] At 805, the UE 810 determines that the event-7 is triggered with X different reference beams within the configured time window. In other words, the event-7 is triggered with a change in the reference beam. At 807, the UE 810 transmits the first PUCCH with the indication of X different reference beams triggering the event-7 to the gNB 820.

[0107] The gNB 820 may receive the first PUCCH, and know the information of the reference beam. At 809, the gNB 820 transmits DCI scheduling a beam report to the UE 810. If the DCI indicates scheduling of a beam report to include the X reference beams,at 811, the UE 810 transmits the beam report with all the X reference beams included to the gNB 820. In other examples, if the DCI indicates scheduling of a beam report to include a number of reference beams less than X, then the UE 810 may need to select one or more reference beams (depending on the scheduling of the gNB 820) from all the X different reference beams.

[0108] FIG. 9A shows a flowchart of an example method 900A implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 900A will be described from the perspective of the terminal device 110 in FIG. 1.

[0109] At block 910, the terminal device 110 determines that at least one condition for a trigger event is satisfied.

[0110] At block 920, the terminal device 110 selects, according to a specified criterion, one or more reference beams to be reported in a beam report, from at least one reference beam that is involved in satisfaction of the at least one condition for the trigger event.[OHl] At block 930, the terminal device 110 transmits, to a network device, the beam report comprising an indication of the one or more reference beams.

[0112] In some example embodiments, the at least one reference beam includes at least one of the following characteristics: being measured to satisfy a configured quality; or being in an activated transmission configuration indication, TCI, state.

[0113] In some example embodiments, the specified criterion is configured by the network device or is pre-specified at the first apparatus.

[0114] In some example embodiments, the determining whether the at least one condition for the trigger event is satisfied involves a configured time window. The specified criterion is determined based on the configured time window.

[0115] In some example embodiments, the selected one or more reference beams to be reported in the beam report comprise at least one of the following: a latest measured reference beam at an end of the configured time window; or a latest measured reference beam at a beginning of the configured time window.

[0116] In some example embodiments, the at least one reference beam is measured within the configured time window, and the selected one or more reference beams to be reportedin the beam report comprise at least one of the following: a reference beam with a highest signal quality within the configured time window; or a reference beam with a greatest number of measurement times within the configured time window; or a latest measured reference beam at an end of the configured time window, in accordance with a determination of more than one reference beam that occupies a same period of time within the configured time window.

[0117] In some example embodiments, the selected one or more reference beams to be reported in the beam report comprise: a reference beam, in accordance with a determination that the reference beam remains unchanged within the configured time window.

[0118] In some example embodiments, the specified criterion is determined based on reception of at least one downlink reference signal from the network device.

[0119] In some example embodiments, the selected one or more reference beams to be reported in the beam report comprise: a reference beam associated with a latest reception of a downlink reference signal.

[0120] In some example embodiments, the determining whether the at least one condition for the trigger event is satisfied involves a configured time window, and the beam report is transmitted on a transmission occasion. The specified criterion is determined based on: a first uplink transmission towards the network device after an end of the configured time window, or the transmission occasion.

[0121] In some example embodiments, the method 900A further comprises: transmitting, to the network device, an indication of the number of reference beam; receiving, from the network device, an uplink resource scheduled for transmission of the beam report; and transmitting, to the network device, the beam report using the uplink resource.

[0122] In some example embodiments, the method 900A further comprises: in accordance with a determination that the uplink resource is available for transmission of a beam report with one or more reference beams, transmitting to the network device, the beam report comprising the indication of the one or more reference beams selected from the at least one reference beam; and in accordance with a determination that the uplink resource is available for transmission of a beam report with the plurality of reference beams, transmitting to the network device, the beam report at least including respectiveindications of the plurality of reference beams.

[0123] In some example embodiments, the beam report further comprises at least one indication of at least one beam that is measured to be with a threshold value better than the at least one reference beam.

[0124] In some example embodiments, the method 900A further comprises: receiving, from the network device, configuration for the trigger event.

[0125] In some example embodiments, the first apparatus is or is comprised in a terminal device.

[0126] FIG. 9B shows a flowchart of an example method 900B implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 900B will be described from the perspective of the network device 120 in FIG. 1.

[0127] At block 940, the network device 120 receives, from a terminal device, a beam report comprising an indication of one or more reference beams selected from at least one reference beam that is involved in satisfaction of at least one condition for a trigger event.

[0128] At block 950, the network device 120 determines occurrence of the one or more reference beams with respect to a configured time window based on a criterion specified for the terminal device, wherein the configured time window is configured for the terminal device to determine whether the at least one condition for the trigger event is satisfied.

[0129] In some example embodiments, the at least one reference beam includes at least one of the following characteristics: being measured to satisfy a configured quality; or being in an activated transmission configuration indication, TCI, state.

[0130] In some example embodiments, the one or more reference beams indicated in the beam report comprise at least one of the following: a latest measured reference beam at an end of the configured time window; or a latest measured reference beam at a beginning of the configured time window.

[0131] In some example embodiments, the one or more reference beams indicated in the beam report comprise at least one of the following: a reference beam with a highest signal quality within the configured time window; or a reference beam with a greatest number of measurement times within the configured time window; or a latest measured referencebeam at an end of the configured time window, in accordance with a determination of more than one reference beam that occupies a same period of time within the configured time window.

[0132] In some example embodiments, the one or more reference beams indicated in the beam report comprise: a reference beam that remains unchanged within the configured time window.

[0133] In some example embodiments, the method 900B further comprises: receiving, from the terminal device, an indication of the number of reference beam; transmitting, to the terminal device, an uplink resource scheduled for transmission of the beam report; and receiving the beam report from the terminal device on the uplink resource.

[0134] In some example embodiments, the method 900B further comprises: based on the uplink resource being available for transmission of a beam report with one or more reference beams, receiving from the terminal device, the beam report comprising the indication of the one or more reference beams selected from the at least one reference beam; and based on the uplink resource being available for transmission of a beam report with the plurality of reference beams, receiving from the terminal device, the beam report at least including respective indications of the plurality of reference beams.

[0135] In some example embodiments, the method 900B further comprises: transmitting, to the terminal device, signaling indicating the specified criterion.

[0136] In some example embodiments, the method 900B further comprises: transmitting, to the terminal device, configuration for the trigger event.

[0137] In some example embodiments, a first apparatus capable of performing any of the method 900A (for example, the terminal device 110 in FIG. 1) may comprise means for performing the respective operations of the method 900A. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the terminal device 110 in FIG. 1.

[0138] In some example embodiments, the first apparatus comprises means for determining that at least one condition for a trigger event is satisfied; means for selecting, according to a specified criterion, one or more reference beams to be reported in a beam report, from at least one reference beam that is involved in satisfaction of the at least onecondition for the trigger event; and means for transmitting, to a network device, the beam report comprising an indication of the one or more reference beams.

[0139] In some example embodiments, the at least one reference beam includes at least one of the following characteristics: being measured to satisfy a configured quality; or being in an activated transmission configuration indication, TCI, state.

[0140] In some example embodiments, the specified criterion is configured by the network device or is pre-specified at the first apparatus.

[0141] In some example embodiments, the determining whether the at least one condition for the trigger event is satisfied involves a configured time window; and the specified criterion is determined based on the configured time window.

[0142] In some example embodiments, the selected one or more reference beams to be reported in the beam report comprise at least one of the following: a latest measured reference beam at an end of the configured time window; or a latest measured reference beam at a beginning of the configured time window.

[0143] In some example embodiments, the at least one reference beam is measured within the configured time window, and the selected one or more reference beams to be reported in the beam report comprise at least one of the following: a reference beam with a highest signal quality within the configured time window; or a reference beam with a greatest number of measurement times within the configured time window; or a latest measured reference beam at an end of the configured time window, in accordance with a determination of more than one reference beam that occupies a same period of time within the configured time window.

[0144] In some example embodiments, the selected one or more reference beams to be reported in the beam report comprise: a reference beam, in accordance with a determination that the reference beam remains unchanged within the configured time window.

[0145] In some example embodiments, the specified criterion is determined based on reception of at least one downlink reference signal from the network device.

[0146] In some example embodiments, the selected one or more reference beams to be reported in the beam report comprise: a reference beam associated with a latest reception of a downlink reference signal.

[0147] In some example embodiments, the determining whether the at least one condition for the trigger event is satisfied involves a configured time window, and the beam report is transmitted on a transmission occasion. The specified criterion is determined based on: a first uplink transmission towards the network device after an end of the configured time window, or the transmission occasion.

[0148] In some example embodiments, the first apparatus further comprises: means for transmitting, to the network device, an indication of the number of reference beam; means for receiving, from the network device, an uplink resource scheduled for transmission of the beam report; and means for transmitting, to the network device, the beam report using the uplink resource.

[0149] In some example embodiments, the first apparatus further comprises: means for in accordance with a determination that the uplink resource is available for transmission of a beam report with one or more reference beams, transmitting to the network device, the beam report comprising the indication of the one or more reference beams selected from the at least one reference beam; and means for in accordance with a determination that the uplink resource is available for transmission of a beam report with the plurality of reference beams, transmitting to the network device, the beam report at least including respective indications of the plurality of reference beams.

[0150] In some example embodiments, the beam report further comprises at least one indication of at least one beam that is measured to be with a threshold value better than the at least one reference beam.

[0151] In some example embodiments, the first apparatus further comprises: means for receiving, from the network device, configuration for the trigger event.

[0152] In some example embodiments, the first apparatus is or is comprised in a terminal device.

[0153] In some example embodiments, a second apparatus capable of performing any of the method 900B (for example, the network device 120 in FIG. 1) may comprise means for performing the respective operations of the method 900B. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the network device 120 in FIG. 1.

[0154] In some example embodiments, the second apparatus comprises means for receiving, from a terminal device, a beam report comprising an indication of one or more reference beams selected from at least one reference beam that is involved in satisfaction of at least one condition for a trigger event; and means for determining occurrence of the one or more reference beams with respect to a configured time window based on a criterion specified for the terminal device, wherein the configured time window is configured for the terminal device to determine whether the at least one condition for the trigger event is satisfied.

[0155] In some example embodiments, the at least one reference beam includes at least one of the following characteristics: being measured to satisfy a configured quality; or being in an activated transmission configuration indication, TCI, state.

[0156] In some example embodiments, the one or more reference beams indicated in the beam report comprise at least one of the following: a latest measured reference beam at an end of the configured time window; or a latest measured reference beam at a beginning of the configured time window.

[0157] In some example embodiments, the one or more reference beams indicated in the beam report comprise at least one of the following: a reference beam with a highest signal quality within the configured time window; or a reference beam with a greatest number of measurement times within the configured time window; or a latest measured reference beam at an end of the configured time window, in accordance with a determination of more than one reference beam that occupies a same period of time within the configured time window.

[0158] In some example embodiments, the one or more reference beams indicated in the beam report comprise: a reference beam that remains unchanged within the configured time window.

[0159] In some example embodiments, the second apparatus further comprises: means for receiving, from the terminal device, an indication of the number of reference beam; means for transmitting, to the terminal device, an uplink resource scheduled for transmission of the beam report; and means for receiving the beam report from the terminal device on the uplink resource.

[0160] In some example embodiments, the second apparatus further comprises: meansfor based on the uplink resource being available for transmission of a beam report with one or more reference beams, receiving from the terminal device, the beam report comprising the indication of the one or more reference beams selected from the at least one reference beam; and means for based on the uplink resource being available for transmission of a beam report with the plurality of reference beams, receiving from the terminal device, the beam report at least including respective indications of the plurality of reference beams.

[0161] In some example embodiments, the second apparatus further comprises: means for transmitting, to the terminal device, signaling indicating the specified criterion.

[0162] In some example embodiments, the second apparatus further comprises: means for transmitting, to the terminal device, configuration for the trigger event.

[0163] FIG. 10A shows a flowchart of an example method 1000 A implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 1000A will be described from the perspective of the terminal device 110 in FIG. 1.

[0164] At block 1010, the terminal device 110 determines that at least one condition for a trigger event is satisfied.

[0165] At block 1020, the terminal device 110 selects, from at least one reference beam that is involved in satisfaction of the at least one condition for the trigger event, a latest measured reference beam at a time of a first uplink transmission towards a network device.

[0166] At block 1030, the terminal device 110 transmits, to the network device, a beam report comprising an indication of the latest measured reference beam at the time of the first uplink transmission towards the network device.

[0167] In some example embodiments, the determining whether the at least one condition for the trigger event is satisfied involves a configured time window.

[0168] In some example embodiments, the at least one reference beam includes at least one of the following characteristics: being measured to satisfy a configured quality; or being in an activated transmission configuration indication, TCI, state.

[0169] In some example embodiments, the first uplink transmission comprises a first uplink transmission outside of the configured time window.

[0170] In some example embodiments, the first uplink transmission comprises a first transmission of uplink control information.

[0171] In some example embodiments, the method 1000 A further comprises: receiving, from the network device, signaling indicating a specified criterion of selecting the latest measured reference beam at the time of the first uplink transmission for beam reporting; and selecting the latest measured reference beam for the beam report by applying the specified criterion.

[0172] In some example embodiments, the method 1000 A further comprises: transmitting, to the network device, an indication of the number of reference beam; receiving, from the network device, an uplink resource scheduled for transmission of the beam report; and transmitting, to the network device, the beam report using the uplink resource.

[0173] In some example embodiments, the method 1000A further comprises: in accordance with a determination that the uplink resource is available for transmission of a beam report with one reference beam, transmitting to the network device, the beam report comprising the indication of the latest measured reference beam at the time of the first uplink transmission towards the network device; and in accordance with a determination that the uplink resource is available for transmission of a beam report with the plurality of reference beams, transmitting to the network device, the beam report at least including respective indications of the plurality of reference beams.

[0174] In some example embodiments, the beam report further comprises at least one indication of at least one beam that is measured to be with a threshold value better than the at least one reference beam.

[0175] In some example embodiments, the method 1000 A further comprises: receiving, from the network device, configuration for the trigger event.

[0176] In some example embodiments, the first apparatus is or is comprised in a terminal device.

[0177] FIG. 10B shows a flowchart of an example method 1000B implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 1000B will be described from the perspective of the network device 120 in FIG. 1.

[0178] At block 1040, the network device 120 receives, from a terminal device, a beam report comprising an indication of a reference beam for a trigger event.

[0179] At block 1050, the network device 120 determines that the reference beam is a latest reference beam measured by the terminal device at a time of a first uplink transmission, among at least one reference beam that is involved in satisfaction of at least one condition for the trigger event.

[0180] In some example embodiments, the at least one reference beam includes at least one of the following characteristics: being measured to satisfy a configured quality; or being in an activated transmission configuration indication, TCI, state.

[0181] In some example embodiments, the first uplink transmission comprises a first uplink transmission outside of a configured time window, wherein the determining whether the at least one condition for the trigger event is satisfied involves a configured time window.

[0182] In some example embodiments, the first uplink transmission comprises a first transmission of uplink control information.

[0183] In some example embodiments, the method 1000B further comprises: transmitting, to the terminal device, signaling indicating a specified criterion of selecting the latest measured reference beam at the time of the first uplink transmission for beam reporting.

[0184] In some example embodiments, the method 1000B further comprises: transmitting, to the terminal device, configuration for the trigger event.

[0185] In some example embodiments, a first apparatus capable of performing any of the method 1000A (for example, the terminal device 110 in FIG. 1) may comprise means for performing the respective operations of the method 1000A. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the terminal device 110 in FIG. 1.

[0186] In some example embodiments, the first apparatus comprises means for determining that at least one condition for a trigger event is satisfied; means for selecting, from at least one reference beam that is involved in satisfaction of the at least one condition for the trigger event, a latest measured reference beam at a time of a first uplinktransmission towards a network device; and means for transmitting, to the network device, a beam report comprising an indication of the latest measured reference beam at the time of the first uplink transmission towards the network device.

[0187] In some example embodiments, the determining whether the at least one condition for the trigger event is satisfied involves a configured time window.

[0188] In some example embodiments, the at least one reference beam includes at least one of the following characteristics: being measured to satisfy a configured quality; or being in an activated transmission configuration indication, TCI, state.

[0189] In some example embodiments, the first uplink transmission comprises a first uplink transmission outside of the configured time window.

[0190] In some example embodiments, the first uplink transmission comprises a first transmission of uplink control information.

[0191] In some example embodiments, the first apparatus further comprises: means for receiving, from the network device, signaling indicating a specified criterion of selecting the latest measured reference beam at the time of the first uplink transmission for beam reporting; and means for selecting the latest measured reference beam for the beam report by applying the specified criterion.

[0192] In some example embodiments, the first apparatus further comprises: means for transmitting, to the network device, an indication of the number of reference beam; means for receiving, from the network device, an uplink resource scheduled for transmission of the beam report; and means for transmitting, to the network device, the beam report using the uplink resource.

[0193] In some example embodiments, the first apparatus further comprises: means for in accordance with a determination that the uplink resource is available for transmission of a beam report with one reference beam, transmitting to the network device, the beam report comprising the indication of the latest measured reference beam at the time of the first uplink transmission towards the network device; and means for in accordance with a determination that the uplink resource is available for transmission of a beam report with the plurality of reference beams, transmitting to the network device, the beam report at least including respective indications of the plurality of reference beams.

[0194] In some example embodiments, the beam report further comprises at least oneindication of at least one beam that is measured to be with a threshold value better than the at least one reference beam.

[0195] In some example embodiments, the first apparatus further comprises: means for receiving, from the network device, configuration for the trigger event.

[0196] In some example embodiments, the first apparatus is or is comprised in a terminal device.

[0197] In some example embodiments, a second apparatus capable of performing any of the method 1000B (for example, the network device 120 in FIG. 1) may comprise means for performing the respective operations of the method 1000B. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the network device 120 in FIG. 1.

[0198] In some example embodiments, the second apparatus comprises means for receiving, from a terminal device, a beam report comprising an indication of a reference beam for a trigger event; and means for determining that the reference beam is a latest reference beam measured by the terminal device at a time of a first uplink transmission, among at least one reference beam that is involved in satisfaction of at least one condition for the trigger event.

[0199] In some example embodiments, the at least one reference beam includes at least one of the following characteristics: being measured to satisfy a configured quality; or being in an activated transmission configuration indication, TCI, state.

[0200] In some example embodiments, the first uplink transmission comprises a first uplink transmission outside of a configured time window, wherein the determining whether the at least one condition for the trigger event is satisfied involves a configured time window.

[0201] In some example embodiments, the first uplink transmission comprises a first transmission of uplink control information.

[0202] In some example embodiments, the second apparatus further comprises: means for transmitting, to the terminal device, signaling indicating a specified criterion of selecting the latest measured reference beam at the time of the first uplink transmission for beam reporting.

[0203] In some example embodiments, the second apparatus further comprises: means for transmitting, to the terminal device, configuration for the trigger event.

[0204] FIG. 11 A shows a flowchart of an example method 1100 A implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 1100A will be described from the perspective of the terminal device 110 in FIG. 1

[0205] At block 1110, determining that at least one condition for a trigger event is satisfied.

[0206] At block 1120, selecting, from at least one reference beam that is involved in satisfaction of the at least one condition for the trigger event, a latest measured reference beam at a time of transmission of a beam report.

[0207] At block 1130, transmitting, to a network device, the beam report comprising an indication of the latest measured reference beam at the time of the transmission of the beam report.

[0208] In some example embodiments, the determining whether the at least one condition for the trigger event is satisfied involves a configured time window.

[0209] In some example embodiments, the at least one reference beam includes at least one of the following characteristics: being measured to satisfy a configured quality; or being in an activated transmission configuration indication, TCI, state.

[0210] In some example embodiments, the transmission of a beam report is carried in a physical uplink shared channel.

[0211] In some example embodiments, the time of the transmission of the beam report is scheduled by the network device.

[0212] In some example embodiments, the method 1100A further comprises: transmitting, to the network device, a request for transmitting the beam report; receiving, from the network device, scheduling information of a resource for the beam report; and transmitting, to the network device, the beam report using the resource.

[0213] In some example embodiments, the time of the transmission of the beam report is a time of a pre-configured resource of the first apparatus.

[0214] In some example embodiments, the method 1100A further comprises:transmitting, to the network device, an indication indicative of transmission of the beam report; and transmitting, to the network device, the beam report using the pre-configured resource.

[0215] In some example embodiments, the method 1100A further comprises: selecting, among the at least one reference beam, a latest measured reference beam at a time of the transmission for the beam report after an end of a configured time window for determining whether the at least one condition for the trigger event is satisfied.

[0216] In some example embodiments, the method 1100A further comprises: receiving, from the network device, signaling indicating a specified criterion of selecting the latest measured reference beam at the time of the transmission of the beam report for beam reporting; and selecting the latest measured reference beam for the beam report by applying the specified criterion.

[0217] In some example embodiments, the method 1100A further comprises: transmitting, to the network device, an indication of the number of reference beam; receiving, from the network device, an uplink resource scheduled for transmission of the beam report; and transmitting, to the network device, the beam report using the uplink resource.

[0218] In some example embodiments, the method 1100A further comprises: in accordance with a determination that the uplink resource is available for transmission of a beam report with one reference beam, transmitting to the network device, the beam report comprising the indication of the latest measured reference beam at the time of the transmission of the beam report; and in accordance with a determination that the uplink resource is available for transmission of a beam report with the plurality of reference beams, transmitting to the network device, the beam report at least including respective indications of the plurality of reference beams.

[0219] In some example embodiments, the beam report further comprises at least one indication of at least one beam that is measured to be with a threshold value better than the at least one reference beam.

[0220] In some example embodiments, the method 1100A further comprises: receiving, from the network device, configuration for the trigger event.

[0221] In some example embodiments, the first apparatus is or is comprised in a terminaldevice.

[0222] FIG. 11B shows a flowchart of an example method 1100B implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 1100B will be described from the perspective of the network device 120 in FIG. 1.

[0223] At block 1140, the network device 120 receives, from a terminal device, a beam report comprising an indication of a reference beam for a trigger event.

[0224] At block 1150, the network device 120 determines that the reference beam is a latest reference beam measured by the terminal device at a time of transmission of the beam report, among at least one reference beam that is involved in satisfaction of at least one condition for the trigger event.

[0225] In some example embodiments, the at least one reference beam includes at least one of the following characteristics: being measured to satisfy a configured quality; or being in an activated transmission configuration indication, TCI, state.

[0226] In some example embodiments, the transmission of a beam report is carried in a physical uplink shared channel.

[0227] In some example embodiments, the time of the transmission of the beam report is scheduled by the network device.

[0228] In some example embodiments, the method 1100B further comprises: receiving, from the terminal device, a request for transmitting the beam report; transmitting, to the terminal device, scheduling information of a resource for the beam report; and receiving, from the terminal device, the beam report on the resource.

[0229] In some example embodiments, the time of the transmission of the beam report is a time of a pre-configured resource of the terminal device.

[0230] In some example embodiments, the method 1100B further comprises: receiving, from the terminal device, an indication indicative of transmission of the beam report; and receiving, from the terminal device, the beam report on the pre-configured resource.

[0231] In some example embodiments, the latest measured reference beam indicated in the beam report comprise a latest measured reference beam at a time of the transmission for the beam report after an end of a configured time window for determining whether theat least one condition for the trigger event is satisfied.

[0232] In some example embodiments, the method 1100B further comprises: transmitting, to the terminal device, signaling indicating a specified criterion of selecting the latest measured reference beam at the time of the transmission of the beam report for beam reporting.

[0233] In some example embodiments, the method 1100B further comprises: transmitting, to the terminal device, configuration for the trigger event.

[0234] In some example embodiments, a first apparatus capable of performing any of the method 1100A (for example, the terminal devicellO in FIG. 1) may comprise means for performing the respective operations of the method 1100A. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the terminal device 110 in FIG. 1.

[0235] In some example embodiments, the first apparatus comprises means for determining that at least one condition for a trigger event is satisfied; means for selecting, from at least one reference beam that is involved in satisfaction of the at least one condition for the trigger event, a latest measured reference beam at a time of transmission of a beam report; and means for transmitting, to a network device, the beam report comprising an indication of the latest measured reference beam at the time of the transmission of the beam report.

[0236] In some example embodiments, the determining whether the at least one condition for the trigger event is satisfied involves a configured time window.

[0237] In some example embodiments, the at least one reference beam includes at least one of the following characteristics: being measured to satisfy a configured quality; or being in an activated transmission configuration indication, TCI, state.

[0238] In some example embodiments, the transmission of a beam report is carried in a physical uplink shared channel.

[0239] In some example embodiments, the time of the transmission of the beam report is scheduled by the network device.

[0240] In some example embodiments, the first apparatus further comprises: means fortransmitting, to the network device, a request for transmitting the beam report; means for receiving, from the network device, scheduling information of a resource for the beam report; and means for transmitting, to the network device, the beam report using the resource.

[0241] In some example embodiments, the time of the transmission of the beam report is a time of a pre-configured resource of the first apparatus.

[0242] In some example embodiments, the first apparatus further comprises: means for transmitting, to the network device, an indication indicative of transmission of the beam report; and means for transmitting, to the network device, the beam report using the preconfigured resource.

[0243] In some example embodiments, the first apparatus further comprises: means for selecting, among the at least one reference beam, a latest measured reference beam at a time of the transmission for the beam report after an end of a configured time window for determining whether the at least one condition for the trigger event is satisfied.

[0244] In some example embodiments, the first apparatus further comprises: means for receiving, from the network device, signaling indicating a specified criterion of selecting the latest measured reference beam at the time of the transmission of the beam report for beam reporting; and means for selecting the latest measured reference beam for the beam report by applying the specified criterion.

[0245] In some example embodiments, the first apparatus further comprises: means for transmitting, to the network device, an indication of the number of reference beam; means for receiving, from the network device, an uplink resource scheduled for transmission of the beam report; and means for transmitting, to the network device, the beam report using the uplink resource.

[0246] In some example embodiments, the first apparatus further comprises: means for in accordance with a determination that the uplink resource is available for transmission of a beam report with one reference beam, transmitting to the network device, the beam report comprising the indication of the latest measured reference beam at the time of the transmission of the beam report; and means for in accordance with a determination that the uplink resource is available for transmission of a beam report with the plurality of reference beams, transmitting to the network device, the beam report at least includingrespective indications of the plurality of reference beams.

[0247] In some example embodiments, the beam report further comprises at least one indication of at least one beam that is measured to be with a threshold value better than the at least one reference beam.

[0248] In some example embodiments, the first apparatus further comprises: means for receiving, from the network device, configuration for the trigger event.

[0249] In some example embodiments, the first apparatus is or is comprised in a terminal device.

[0250] In some example embodiments, a second apparatus capable of performing any of the method 1100B (for example, the network device 120 in FIG. 1) may comprise means for performing the respective operations of the method 1100B. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the network device 120 in FIG. 1.

[0251] In some example embodiments, the second apparatus comprises means for receiving, from a terminal device, a beam report comprising an indication of a reference beam for a trigger event; and means for determining that the reference beam is a latest reference beam measured by the terminal device at a time of transmission of the beam report, among at least one reference beam that is involved in satisfaction of at least one condition for the trigger event.

[0252] In some example embodiments, the at least one reference beam includes at least one of the following characteristics: being measured to satisfy a configured quality; or being in an activated transmission configuration indication, TCI, state.

[0253] In some example embodiments, the transmission of a beam report is carried in a physical uplink shared channel.

[0254] In some example embodiments, the time of the transmission of the beam report is scheduled by the network device.

[0255] In some example embodiments, the second apparatus further comprises: means for receiving, from the terminal device, a request for transmitting the beam report; means for transmitting, to the terminal device, scheduling information of a resource for the beamreport; and means for receiving, from the terminal device, the beam report on the resource.

[0256] In some example embodiments, the time of the transmission of the beam report is a time of a pre-configured resource of the terminal device.

[0257] In some example embodiments, the second apparatus further comprises: means for receiving, from the terminal device, an indication indicative of transmission of the beam report; and means for receiving, from the terminal device, the beam report on the pre-configured resource.

[0258] In some example embodiments, the latest measured reference beam indicated in the beam report comprise a latest measured reference beam at a time of the transmission for the beam report after an end of a configured time window for determining whether the at least one condition for the trigger event is satisfied.

[0259] In some example embodiments, the second apparatus further comprises: means for transmitting, to the terminal device, signaling indicating a specified criterion of selecting the latest measured reference beam at the time of the transmission of the beam report for beam reporting.

[0260] In some example embodiments, the second apparatus further comprises: means for transmitting, to the terminal device, configuration for the trigger event.

[0261] FIG. 12 is a simplified block diagram of a device 1200 that is suitable for implementing example embodiments of the present disclosure. The device 1200 may be provided to implement a communication device, for example, the terminal device 110 or the network device 120 as shown in FIG. 1. As shown, the device 1200 includes one or more processors 1210, one or more memories 1220 coupled to the processor 1210, and one or more communication modules 1240 coupled to the processor 1210.

[0262] The communication module 1240 is for bidirectional communications. The communication module 1240 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 1240 may include at least one antenna.

[0263] The processor 1210 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purposecomputers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 1200 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.

[0264] The memory 1220 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) 1224, 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) 1222 and other volatile memories that will not last in the power-down duration.

[0265] A computer program 1230 includes computer executable instructions that are executed by the associated processor 1210. The instructions of the program 1230 may include instructions for performing operations / acts of some example embodiments of the present disclosure. The program 1230 may be stored in the memory, e.g., the ROM 1224. The processor 1210 may perform any suitable actions and processing by loading the program 1230 into the RAM 1222.

[0266] The example embodiments of the present disclosure may be implemented by means of the program 1230 so that the device 1200 may perform any process of the disclosure as discussed with reference to FIG. 4 to FIG. 11B. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0267] In some example embodiments, the program 1230 may be tangibly contained in a computer readable medium which may be included in the device 1200 (such as in the memory 1220) or other storage devices that are accessible by the device 1200. The device 1200 may load the program 1230 from the computer readable medium to the RAM 1222 for execution. In some example embodiments, the computer readable medium may include any types of non-transitory storage medium, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0268] FIG. 13 shows an example of the computer readable medium 1300 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 1300 has the program 1230 stored thereon.

[0269] 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.

[0270] Some example embodiments of the present disclosure also provide at least one computer program product tangibly stored on a computer readable medium, such as a non-transitory computer readable medium. The computer program product includes computerexecutable instructions, such as those included in program modules, being executed in a device on a target physical or virtual processor, to carry out any of the methods as described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

[0271] 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.

[0272] In the context of the present disclosure, the computer program code or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

[0273] 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.

[0274] 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 sub-combination.

[0275] 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

47WHAT IS CLAIMED IS:

1. A first apparatus comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to:determine that at least one condition for a trigger event is satisfied;select, according to a specified criterion, one or more reference beams to be reported in a beam report, from at least one reference beam that is involved in satisfaction of the at least one condition for the trigger event; andtransmit, to a network device, the beam report comprising an indication of the one or more reference beams.

2. The first apparatus of claim 1, wherein the at least one reference beam includes at least one of the following characteristics:being measured to satisfy a configured quality; orbeing in an activated transmission configuration indication, TCI, state.

3. The first apparatus of claim 1, wherein the specified criterion is configured by the network device or is pre-specified at the first apparatus.

4. The first apparatus of any of claims 1 to 3, whereinthe determining whether the at least one condition for the trigger event is satisfied involves a configured time window; andthe specified criterion is determined based on the configured time window.

5. The first apparatus of claim 4, wherein the selected one or more reference beams to be reported in the beam report comprise at least one of the following:a latest measured reference beam at an end of the configured time window; or a latest measured reference beam at a beginning of the configured time window.

6. The first apparatus of claim 4, wherein the at least one reference beam is measured within the configured time window, and the selected one or more reference48beams to be reported in the beam report comprise at least one of the following:a reference beam with a highest signal quality within the configured time window; ora reference beam with a greatest number of measurement times within the configured time window; ora latest measured reference beam at an end of the configured time window, in accordance with a determination of more than one reference beam that occupies a same period of time within the configured time window.

7. The first apparatus of claim 4, wherein the selected one or more reference beams to be reported in the beam report comprise:a reference beam, in accordance with a determination that the reference beam remains unchanged within the configured time window.

8. The first apparatus of any of claims 1 to 3, wherein the specified criterion is determined based on reception of at least one downlink reference signal from the network device.

9. The first apparatus of claim 8, wherein the selected one or more reference beams to be reported in the beam report comprise:a reference beam associated with a latest reception of a downlink reference signal.

10. The first apparatus of any of claims 1 to 3, wherein the determining whether the at least one condition for the trigger event is satisfied involves a configured time window, wherein the beam report is transmitted on a transmission occasion; and wherein the specified criterion is determined based on:a first uplink transmission towards the network device after an end of the configured time window, orthe transmission occasion.

11. The first apparatus of any of claims 1 to 10, wherein the first apparatus is caused to:transmit, to the network device, an indication of the number of reference beam; receive, from the network device, an uplink resource scheduled for transmission49of the beam report; andtransmit, to the network device, the beam report using the uplink resource.

12. The first apparatus of claim 11, wherein the at least one reference beam comprises a plurality of reference beams, and the first apparatus is caused to:in accordance with a determination that the uplink resource is available for transmission of a beam report with one or more reference beams, transmit, to the network device, the beam report comprising the indication of the one or more reference beams selected from the at least one reference beam; andin accordance with a determination that the uplink resource is available for transmission of a beam report with the plurality of reference beams, transmit, to the network device, the beam report at least including respective indications of the plurality of reference beams.

13. The first apparatus of any of claims 1 to 12, wherein the beam report further comprises at least one indication of at least one beam that is measured to be with a threshold value better than the at least one reference beam.

14. The first apparatus of any of claims 1 to 13, wherein the first apparatus is caused to:receive, from the network device, configuration for the trigger event.

15. The first apparatus of any of claims 1 to 14, wherein the first apparatus is or is comprised in a terminal device.

16. A second apparatus comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus at least to:receive, from a terminal device, a beam report comprising an indication of one or more reference beams selected from at least one reference beam that is involved in satisfaction of at least one condition for a trigger event; anddetermine occurrence of the one or more reference beams with respect to a configured time window based on a criterion specified for the terminal device, wherein50the configured time window is configured for the terminal device to determine whether the at least one condition for the trigger event is satisfied.

17. The second apparatus of claim 16, wherein the at least one reference beam includes at least one of the following characteristics:being measured to satisfy a configured quality; orbeing in an activated transmission configuration indication, TCI, state.

18. The second apparatus of claim 16 or 17, wherein the one or more reference beams indicated in the beam report comprise at least one of the following:a latest measured reference beam at an end of the configured time window; or a latest measured reference beam at a beginning of the configured time window.

19. The second apparatus of claim 16 or 17, wherein the one or more reference beams indicated in the beam report comprise at least one of the following:a reference beam with a highest signal quality within the configured time window; ora reference beam with a greatest number of measurement times within the configured time window; ora latest measured reference beam at an end of the configured time window, in accordance with a determination of more than one reference beam that occupies a same period of time within the configured time window.

20. The second apparatus of claim 16 or 17, wherein the one or more reference beams indicated in the beam report comprise:a reference beam that remains unchanged within the configured time window.

21. A method comprising:determining that at least one condition for a trigger event is satisfied; selecting, according to a specified criterion, one or more reference beams to be reported in a beam report, from at least one reference beam that is involved in satisfaction of the at least one condition for the trigger event; andtransmitting, to a network device, the beam report comprising an indication of the one or more reference beams.

22. A method comprising:receiving, from a terminal device, a beam report comprising an indication of one or more reference beams selected from at least one reference beam that is involved in satisfaction of at least one condition for a trigger event; anddetermining occurrence of the one or more reference beams with respect to a configured time window based on a criterion specified for the terminal device, wherein the configured time window is configured for the terminal device to determine whether the at least one condition for the trigger event is satisfied.

23. A first apparatus comprising:means for determining that at least one condition for a trigger event is satisfied; means for selecting, according to a specified criterion, one or more reference beams to be reported in a beam report, from at least one reference beam that is involved in satisfaction of the at least one condition for the trigger event; andmeans for transmitting, to a network device, the beam report comprising an indication of the one or more reference beams.

24. A second apparatus comprising:means for receiving, from a terminal device, a beam report comprising an indication of one or more reference beams selected from at least one reference beam that is involved in satisfaction of at least one condition for a trigger event; andmeans for determining occurrence of the one or more reference beams with respect to a configured time window based on a criterion specified for the terminal device, wherein the configured time window is configured for the terminal device to determine whether the at least one condition for the trigger event is satisfied.

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

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