Periodic event-triggered layer 1 measurement reporting

Abstract

Various example embodiments relate to devices, methods, apparatuses and computer readable media for periodic event-triggered Layer 1 measurement reporting A terminal device may be configured to periodically transmit event-triggered Layer 1 measurement reports to a network device, the event-triggered Layer 1 measurement reports being transmitted on periodic uplink resources associated with an event-triggered Layer 1 measurement reporting after the associated event is met, and to deactivate the periodic transmission of the event-triggered Layer 1 measurement reports in response to a predefined condition being fulfilled.

Description

PERIODIC EVENT-TRIGGERED LAYER 1 MEASUREMENT REPORTINGTECHNICAL FIELD

[0001] Various example embodiments described herein generally relate to communication technologies, and more particularly, to devices, methods, apparatuses and computer readable media for periodic event-triggered Layer 1 measurement reporting.BACKGROUND

[0002] Certain abbreviations that may be found in the description and / or in the figures are herewith defined as follows:ASN.1 Abstract Syntax Notation OneCG Configured GrantCSI Channel State InformationDCI Downlink Control Information gNB next generation Node-BLTM Layer 1 / Layer 2 Triggered MobilityMAC CE Media Access Control ElementMIMO Multiple Input Multiple OutputPDCCH Physical Downlink Control ChannelRRC Radio Resource ControlRS Reference SignalSR Scheduling RequestTA Timing AdvanceTCI Transmission Configuration IndicatorUCI Uplink Control InformationUE User Equipment

[0003] Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM), also known as lower layer triggered mobility, is a procedure in which a base station receives measurement reports (containing LI or Layer 3 (L3) measurements) from user equipment (UE), and on their basis the base station changes UE serving cell by a cell switch command signaled via a media access control element (MAC CE). LTM can offer improvements in handover latency and interruption time compared to Layer 3 (L3) based mobility. L3 mobility uses L3 measurement reporting which supports UE evaluated events for triggering of measurement reports and reduces signaling overheadcompared to periodic measurement reporting. Currently, LI measurement reporting does not support event triggering.SUMMARY

[0004] A brief summary of example embodiments is provided below to provide basic understanding of some aspects of various embodiments. It should be noted that this summary is not intended to identify key features of essential elements or define scopes of the embodiments, and its sole purpose is to introduce some concepts in a simplified form as a preamble for a more detailed description provided below.

[0005] In a first aspect, an example embodiment of a terminal device is provided. The terminal device may comprise at least one processor and at least one memory. The at least one memory may store instructions that, when executed by the at least one processor, cause the terminal device at least to periodically transmit event-triggered Layer 1 measurement reports to a network device, the event-triggered Layer 1 measurement reports being transmitted on periodic uplink resources associated with an event-triggered Layer 1 measurement reporting after the associated event is met, and to deactivate the periodic transmission of the event-triggered Layer 1 measurement reports in response to a predefined condition being fulfilled.

[0006] In a second aspect, an example embodiment of a network device is provided. The network device may comprise at least one processor and at least one memory. The at least one memory may store instructions that, when executed by the at least one processor, cause the network device at least to periodically receive event-triggered Layer 1 measurement reports from a terminal device, the event-triggered Layer 1 measurement reports being received on periodic uplink resources associated with an event-triggered Layer 1 measurement reporting after the associated event is met, and to stop receiving the event-triggered Layer 1 measurement reports in response to a predefined condition being fulfilled.

[0007] Example embodiments of methods, apparatuses and computer readable media are also provided, which generally correspond to the above-described example embodiments and a repetitive description thereof is omitted here for convenience.

[0008] Other features and advantages of the example embodiments of the present disclosure will also be apparent from the following description of specific embodiments when read in conjunction with the accompanying drawings, which illustrate, by way of example, the principles of example embodiments of the present disclosure.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Some example embodiments will now be described, by way of non-limiting examples, with reference to the accompanying drawings.

[0010] Fig lAis a schematic message flow diagram illustrating an example of an event-driven beam reporting procedure.

[0011] Fig IB is a schematic message flow diagram illustrating another example of an event- driven beam reporting procedure.

[0012] Fig 2 is a schematic message flow diagram illustrating an example of an event-triggered Layer 1 (LI) measurement reporting procedure.

[0013] Fig 3 is a schematic message flow diagram illustrating another example of an event- triggered LI measurement reporting procedure.

[0014] Fig 4 is a schematic flowchart illustrating an example of a method implemented at user equipment (UE).

[0015] Fig 5 is a schematic flowchart illustrating another example of a method implemented at UE.

[0016] Fig 6 is a schematic block diagram illustrating an example of an apparatus.

[0017] Fig 7 is a schematic flowchart illustrating an example of a method implemented at a base station.

[0018] Fig 8 is a schematic flowchart illustrating another example of a method implemented at a base station.

[0019] Fig 9 is a schematic block diagram illustrating an example of an apparatus.

[0020] Fig 10 is a schematic message flow diagram illustrating an example of a procedure of deactivating event-triggered LI measurement reporting.

[0021] Fig 11 is a schematic flowchart illustrating an example of a method implemented at UE.

[0022] Fig 12 is a schematic block diagram illustrating an example of an apparatus.

[0023] Fig 13 is a schematic flowchart illustrating an example of a method implemented at a base station.

[0024] Fig 14 is a schematic block diagram illustrating an example of an apparatus.

[0025] Fig 15 is a schematic block diagram illustrating an example of a terminal device.

[0026] Fig 16 is a schematic block diagram illustrating an example of a network device.

[0027] Throughout the drawings, same or similar reference numbers indicate same or similar elements. A repetitive description on the same elements would be omitted.DETAILED DESCRIPTION

[0028] Herein below, some example embodiments are described in detail with reference to the accompanying drawings. The following description shows details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known circuits, techniques and components are shown in block diagram form to avoid obscuring the described concepts and features.

[0029] As used herein, the term “terminal device” or “user equipment” (UE) refers to any entities or devices that can wirelessly communicate with the network devices or with each other. Examples of the terminal device can include a mobile phone, a mobile terminal (MT), a mobile station (MS), a subscriber station (SS), a portable subscriber station (PSS), an access terminal (AT), a computer, a wearable device, an on-vehicle communication device, a machine type communication (MTC) device, a D2D communication device, a V2X communication device, a sensor and the like. The term “terminal device” can be used interchangeably with UE, user terminal, mobile terminal, mobile station, or wireless device.

[0030] As used herein, the term “network device” refers to any suitable entities or devices that can provide cells or coverage, through which the terminal device can access the network or receive services. The network device may be referred to as a base station. The term “base station” used herein can represent a node B (NodeB or NB), an evolved node B (eNodeB or eNB), or a gNB or a like. The base station may be embodied as a macro base station, a relay node, or a low power node such as a pico base station or a femto base station. The base station may consist of several distributed network units, such as a central unit (CU), one or more distributed units (DUs), one or more remote radio heads (RRHs) or remote radio units (RRUs). The number and functions of these distributed units depend on the selected split RAN architecture.

[0031] Enhancements for mobility are under investigation, with an objective to support event- triggered LI measurement reporting in LTM for reducing overhead. In addition, LI measurement reporting is also used in beam management, and enhancements for multiple input multiple output (MIMO) include an objective to facilitate UE-initiated / event-driven beam management (BM). Two modes for event-driven beam reporting have been proposed for UE-initiated / event-driven BM, i.e., Mode A where beam reports are dynamically scheduled, and Mode B where beam reports are transmitted on pre-configured resources. Fig. 1 A illustrates beam report transmission procedure 100A according to Mode A, and Fig. IB illustrates beam report transmission procedure 100B according to Mode B. Referring to Fig. 1 A first, at 110, UE 10 may transmit to base station (BS) 20 a first uplink (UL) channel to request a resource for a second UL channel tocarry a beam report. In response to the request, base station 20 may dynamically allocate resources for the second UL channel to carry the beam report and send the resource allocation to UE 10 at 112. Upon detecting the resource allocation, UE 10 may transmit the beam report on the second UL channel to base station 20 at 114.

[0032] Referring to Fig. IB, in beam report transmission procedure 100B of Mode B, UE 10 may transmit a first UL channel notifying a second UL channel to carry beam report at 120. Then, UE 10 may transmit the beam report in the second UL channel at 122. The beam report is transmitted on pre-configured resources in the second UL channel, and base station 20 does not need to dynamically schedule resources for each beam report.

[0033] The event-triggered reporting in Mode A (i.e., procedure 100A) is considered as basic UE capability which shall be supported by all UEs supporting UE-initiated / event-driven beam reporting. Unfortunately, Mode A is not suitable for periodic reporting because each transmission on the second UL channel requires transmission of the first UL channel in order to acquire dynamical resource allocation for the second UL channel. Some use cases may require UE to periodically report information to the network as long as a condition for an event triggering the report is satisfied. For example, it is expected in mobility enhancements that event-triggered LI measurement reporting should be designed for the purposes of selecting a candidate beam / cell to trigger early DL or / and UL synchronization and selecting a target beam / cell to trigger the LTM cell switch procedure. In such use cases, UE may be required to periodically transmit event- triggered LI measurement reports such that the network can quickly react to beam / cell quality change and enable transmission configuration indicator (TCI) state activation and early uplink synchronization for a candidate target beam / cell.

[0034] Example embodiments of the present disclosure enable a periodic event-triggered LI measurement reporting. Aperiodic event-triggered LI measurement reporting refers to that after an event configured for an event-triggered reporting is met, the UE periodically reports the measurements associated with the event-triggered reporting. In each instance of the periodic reporting, the reported measurements may be same or different. For example, if UE is configured to report N number of beams in a report, then at each instance of the periodic reporting, the UE may report the N best beams from the, e.g., latest, measurements associated with the event- triggered reporting. Some example embodiments provide methods for enabling and indicating resources for the periodic event-triggered LI measurement reporting. The resources may comprise pre-configured periodic resources or dynamically scheduled resources. Some example embodiments provide methods for activating and deactivating the periodic event-triggered LI measurement reporting and introduce new triggers for activation and deactivation of the periodicevent-triggered LI measurement reporting and / or the pre-configured periodic resources. An efficient way for the periodic event-triggered LI measurement reporting is provided, which can reduce latency, overhead and interruption time in the LTM or beam management procedure. Beam management procedure refers to intra-cell or inter-cell beam management procedure without any change in the serving cell. Some examples or embodiments are described below in the context of the above-mentioned Mode A, but they are also applicable for the above- mentioned Mode B. Throughout the disclosure, the terms “event-triggered”, “event-based” and “event-driven” can be interchangeably used.

[0035] Fig 2 illustrates an example of event-triggered LI measurement reporting procedure 200. Procedure 200 may be performed in an LTM procedure, a beam management procedure, or other procedures where event-triggered LI measurement reporting may be applied.

[0036] Referring to Fig. 2, at 210, base station 20 may transmit configuration information for one or more event-triggered LI measurement reporting to UE 10. The configuration information for an event-triggered LI measurement reporting may comprise information associated with periodic LI measurement reports upon certain measurement event(s) is triggered. For example, the configuration information may contain information indicating one or more trigger events for the periodic LI measurement reporting. UE 10 may evaluate conditions for the one or more trigger events and, when a condition for any of the one or more trigger events is satisfied, UE 10 will transmit an indication of the event to the network. The one or more trigger events and corresponding conditions may be predefined at base station 20 and UE 10, and different measurement events / conditions may be predefined for different use cases and scenarios. For example, some measurement events / conditions may be defined for event-triggered beam reporting, and some measurement events / conditions may be defined for LI measurement reporting in LTM.

[0037] In an example, configuration information for an event-triggered LI measurement reporting may comprise at least one parameter indicating a periodicity for the periodic LI measurement reporting triggered by the measurement event. For example, the parameter may indicate interval or periodicity for periodic transmissions of the event-triggered LI measurement reports. The configuration information for an event-triggered LI measurement reporting may also comprise a parameter indicating the number of LI measurement reports that are allowed to be transmitted once the corresponding measurement event is triggered.

[0038] In an example, configuration information for an event-triggered LI measurement reporting may comprise information indicating a periodic UL grant configuration configured for the periodic event trigger LI measurement reporting. For example, the configuration informationmay comprise the periodic UL grant configuration per se, or it may comprise information such as a configuration identifier (ID) referring to the periodic UL grant configuration, and the periodic UL grant configuration may be configured in a separate message for UE 10. A UL grant configuration may comprise at least the information of time and frequency domain UL resources. In an example embodiment, the periodic UL grant configuration may comprise a configured grant (CG) configuration that configures CG Type 1 or CG Type 2 for UE 10. The CG configuration may contain information elements (IES) indicating, among others, the interval / periodicity parameter, the LI measurement report number parameter for the periodic UL resources. It is worth noting that CG Type 1 is active / usable since it is configured, and CG Type 2 may need to be activated before use.

[0039] Base station 20 may configure one or more periodic UL grant configurations (e.g., CG configurations) for UE 10 at 210, which each may be assigned with a configuration identifier (ID) to differentiate from each other. The periodic UL grant configuration may be dedicated to / specific for an event-triggered LI measurement reporting, or it may be multiplexed by other data or control information transmissions. In other words, a dedicated periodic UL grant configuration may be provided for an event-triggered LI measurement reporting, or a common or shared periodic UL grant configuration, e.g., used to transmit other data or / and control information, may be provided for an event-triggered LI measurement reporting. In an example, the periodic UL grant configuration may be specific to LI measurement reporting triggered by a certain event, and it may contain or be associated to an event ID of the corresponding event.

[0040] In an example, base station 20 may transmit the configuration information via RRC signaling e.g. RRCReconfiguration to UE 10. The RRCReconfiguration message may also include LTM candidate configuration which configures one or more LTM candidate cells for UE 10. The configuration may comprise one or more event-triggered reporting configurations.

[0041] Upon receiving the configuration information at 210, UE 10 may store the received configurations and transmit an RRCReconfigurationComplete message (not shown) to base station 20.

[0042] An event-triggered reporting configuration may comprise the information of an event to be evaluated or / and information of measurement reference signals (RSs) to be measured. Based on the configuration information, UE 10 may carry out LI measurements on one or more candidate RSs, beams or cells and evaluate whether a condition for a measurement event indicated in the configuration information is satisfied or not. If the condition is satisfied, UE 10 may determine at 211 that the corresponding measurement event is triggered and indicate to base station 20 at 212 that the measurement event is triggered. In an example, base station 20 mayalso consider the event indication as a request for resources to carry the LI measurement reports triggered by the indicated event.

[0043] In response to the event indication, base station 20 may request UE 10 to report LI measurements associated with the indicated event at 214. The request may be carried in a downlink (DL) control message, e.g. downlink control information (DCI). In an example, the DL control message may indicate the event for which the LI measurement reports are requested. If necessary, the DL control message may also contain additional information for transmission of the event-triggered LI measurement reports.

[0044] In an example, the DL control message may contain an indication indicating whether the periodic UL grant configuration configured in the configuration information for the periodic LI measurement reporting is activated for the event-triggered LI measurement reporting. For example, if the periodic UL grant configuration is configured grant (CG) Type 2, the DL control message may indicate whether the CG Type 2 is activated for the event-triggered LI measurement reporting. In an example, the DL control message may comprise a field Fl indicating whether the periodic UL grant configuration is activated or not. In an example, the field Fl may be a bit field having a bit location corresponding to the periodic UL grant configuration. If the bit location is set to a first value e.g. “1”, the corresponding periodic UL grant configuration is activated for the event-triggered LI measurement reporting. If the bit location is set to a second value e.g. “0”, the corresponding periodic UL grant configuration is not activated. In another example, the field Fl may have a value corresponding to e.g. an identifier of the periodic UL grant configuration to be activated. If no periodic UL grant configuration is activated, the field Fl may be set to a certain value.

[0045] In an example, the field Fl may be considered when the DL control message indicates the request for the LI measurement reports. If the DL control message does not indicate the request for the LI measurement reports, the field Fl may be ignored. In another example, the filed Fl may be interpreted as an implicit request for the LI measurement reports. If the field Fl indicates that certain periodic UL grant configuration is activated, UE 10 interprets the field Fl as a request for the LI measurement reports and will transmit the LI measurement reports based on the activated periodic UL grant configuration. If the field Fl indicates that no periodic UL grant configuration is activated, UE 10 interprets it as an indication that the LI measurement reports is not requested and will not transmit the LI measurement reports.

[0046] In an example, if the one or more periodic UL grant configurations configured for UE 10 are specific for event-triggered LI measurement reporting triggered by a certain measurement event, e.g., each periodic UL grant configuration is associated with an event ID, base station 20may configure the field Fl to activate the periodic UL grant configuration associated with the measurement event for which LI measurement reports are requested by base station 20. In an example embodiment, if the one or more periodic UL grant configurations configured for UE 10 are specific for event-triggered LI measurement reporting but not limited to any particular trigger event, base station 20 may configure the field Fl to activate any of the one or more periodic UL grant configurations for the requested LI measurement reports.

[0047] In an example, the field Fl also implies to UE 10 whether the LI measurement reports are requested to be transmitted in a periodic manner. For example, if the field Fl indicates activation of the periodic UL grant configuration, UE 10 interprets it as an indication that the LI measurement reports are requested to be transmitted in a periodic manner. If the field Fl indicates no activation of the periodic UL grant configuration, UE 10 interprets it as an indication that the LI measurement reports are not requested to be transmitted in a periodic manner.

[0048] In some examples, the DL control message may not need to activate the periodic UL grant configuration, and the field Fl may be omitted. For example, if the periodic UL grant configuration configured for UE 10 is CG Type 1, as CG Type 1 is active since it is configured and hence it does not need to be activated, the field F 1 may be omitted in the DL control message. In another example, the periodic UL grant configuration configured for UE 10 may be activated by UE 10, and the DL control message may not include the field Fl to activate the periodic UL grant configuration.

[0049] In some examples, the DL control message may include a field Pl indicating whether the event-triggered LI measurement reports are requested to be transmitted in a periodic manner. For example, if the field Pl is set to a first value e.g. “1”, base station 20 requests UE 10 to transmit the event-triggered LI measurement reports in the periodic manner. If the field Pl is set to a second value e.g. “0”, UE 10 is not requested to transmit the event-triggered LI measurement reports in the periodic manner. In an example, if the field Pl is set to a value indicating UE 10 to transmit the event-triggered LI measurement reports in the periodic manner, and another field indicates the activated periodic UL grant configuration, UE 10 interprets it as an indication that the LI measurement reports are requested to be transmitted in a periodic manner using the activated periodic UL grant. In another example, if the field Pl is set to a value indicating UE 10 to transmit the event-triggered LI measurement reports in the periodic manner, and another field does not indicate the activated periodic UL grant configuration, UE 10 interprets it as an indication that the LI measurement reports are requested to be transmitted in a periodic manner and UE 10 may request UL resource(s) for transmitting the periodic LI measurement reports.

[0050] In an example, if the DL control message indicates a request for the LI measurementreport but it does not activate the periodic UL grant configuration, the DL control message may also include a UL grant for transmission of the requested LI measurement report.

[0051] In an example, the DL control message may comprise downlink control information (DCI), e.g., DCI format 0 1, 0 0 or any DCI format scheduling UL resource allocation.

[0052] With reference to Fig. 2, optionally, UE 10 may decide whether to activate the periodic UL grant configuration or not at 216, if the periodic UL grant configuration can be activated by UE. In some examples, UE 10 may decide activation of the periodic UL grant configuration based on the event-triggered LI measurement report to be transmitted. For example, UE 10 may decide activation of the periodic UL grant configuration based on TCI state and / or UL synchronization status of a candidate cell or a reference signal (RS) / beam of the candidate cell associated with the event-triggered LI measurement report. If at least one TCI state of the RS / beam or candidate cell associated with the event-triggered LI measurement report is activated, and / or UE 10 has acquired UL synchronization with the RS / beam or candidate cell associated with the event-triggered LI measurement report, UE 10 may decide to activate the periodic UL grant configuration for the periodic event-triggered LI measurement reporting. The RSs / beams associated with an event-triggered reporting may refer to the RSs / beams configured to be measured and carry out event evaluation based on those measurements. Otherwise, UE 10 may decide not to activate the periodic UL grant configuration. UE 10 may acquire UL synchronization with the RS / beam or candidate cell through UE-based timing advance (TA) estimate or a contention free random access (CFRA) procedure towards the candidate cell triggered by PDCCH order received from base station 20. In an example, UE 10 may decide activation of the periodic UL grant configuration based on whether the UE has pre-processed the LTM candidate cell configuration or not. For example, if UE 10 has carried out early ASN. l (abstract syntax notation one) decoding or / and validity check for configuration of a certain LTM candidate cell associated with an event-triggered LI measurement reporting before cell switch, UE 10 may decide to activate the periodic UL grant configuration for the periodic event-triggered LI measurement reporting.

[0053] In an example, if UE 10 decides to activate a periodic UL grant configuration for a periodic event-triggered LI measurement reporting at 216, UE 10 may notify (not shown) base station 20 that the periodic UL grant configuration is activated.

[0054] If base station 20 explicitly or implicitly requests UE 10 to transmit the event-triggered LI measurement reports in the periodic manner at 214, then UE 10 may periodically transmit the event-triggered LI measurement reports to base station 20 at 218 based on the periodicity indicated in the configuration information. In an example, UE 10 may transmit the periodicreports via uplink control information (UCI) or MAC CE. If the periodic UL grant configuration has been configured and optionally activated for the event-triggered LI measurement reporting, UE 10 may transmit the periodic event-triggered LI measurement reports via UCI based on the periodic UL grant configuration. If the periodic UL grant configuration is also applicable for other data or control information, UE 10 may multiplex the other data or control information on the periodic UL resources allocated by the periodic UL grant configuration at 218. In an example, UE 10 may prioritize the event-triggered LI measurement reports on the periodic UL resources associated with the periodic UL grant configuration.

[0055] If base station 20 requests UE 10 to transmit the event-triggered LI measurement reports in the periodic manner but it does not configure the periodic UL grant configuration for the event- triggered LI measurement reporting or the periodic UL grant configuration is not activated, UE 10 may request UL resources for each periodic transmission of the event-triggered LI measurement reports. After receiving a UL resource allocation from the network, UE 10 may transmit the event-triggered LI measurement report via MAC CE or UCI based on the UL resource allocation, which will be discussed in detail below.

[0056] In another example, if base station 20 requests the event-triggered LI measurement report from UE 10 but it does not request UE 10 to transmit the report in the periodic manner, UE 10 may transmit the event-triggered LI measurement report for one time. In an example, the DL control message received at 214 may contain a UL grant for the one-time transmission of the requested event-triggered LI measurement report. In another example, UE 10 may use resources allocated in the periodic UL grant configuration for the one-time transmission of the requested event-triggered LI measurement report. In yet another example, UE 10 may request base station 20 to allocate resources for the one-time transmission of the event-triggered LI measurement report.

[0057] UE 10 may continue to carry out LI measurements and transmit the periodic event- triggered LI measurement reports at 218, as long as the condition for the measurement event is satisfied. If the configuration information for the periodic event-triggered LI measurement reporting provisions the number of reports that are allowed to be transmitted, UE 10 may stop the periodic reporting when the provisioned number of reports have been transmitted, or when the provisioned number of occasions of the periodic UL resources for the periodic event- triggered LI measurement reporting have elapsed regardless of whether the number of reports have been actually transmitted.

[0058] In the above examples, procedure 200 provides an effective way for periodic event- triggered LI measurement reporting, especially when the periodic UL grant configuration is usedfor the reporting. The network can configure UE with one or more periodic UL grant configurations specific for periodic event-triggered LI measurement reporting or specific for periodic reporting triggered by certain measurement event(s). The network can configure the periodicity of the periodic reporting to achieve balance between overhead and latency.

[0059] Fig 3 illustrates another example of event-triggered LI measurement reporting procedure 200A. Procedure 200A is a variant of procedure 200 shown in Fig. 2, and it includes some same or similar blocks denoted with the same reference numerals. Here the description will focus on the different blocks, and a repetitive description for the same blocks is omitted.

[0060] Referring to Fig. 3, it is assumed that base station 20 requests UE 10 to transmit the event-triggered LI measurement reports in the periodic manner at 214, but neither base station 20 nor UE 10 activates any periodic UL grant configuration for the periodic event-triggered LI measurement reporting, or base station 20 does not configure the periodic UL grant configuration for UE 10 at 210. Then UE 10 may carry out at 218 a periodic transmission of the requested event-triggered LI measurement reports as follows.

[0061] At 220, UE 10 may request base station 20 to allocate UL resources for at least one transmission of the event-triggered LI measurement report. For example, UE 10 may transmit a scheduling request (SR), a new UCI type, or a random access channel (RACH) preamble to base station 20 to request the UL resource allocation.

[0062] In response to the resource request received from UE 10, base station 20 may allocate UL resources for UE 10 and transmit a UL grant to UE 10 at 222.

[0063] Then UE 10 may transmit the event-triggered LI measurement report based on the UL grant at 224.

[0064] In an example, blocks 220-224 may be repeatedly carried out for each transmission of the event-triggered LI measurement report. In another example, if the DL control message received at 214 contains a UL grant for UE 10, UE 10 may transmit the first LI measurement report based on the UL grant and then carry out blocks 220-224 for each subsequent LI measurement report. In yet another example, base station 20 may configure periodic UL resources (e.g., by a periodic UL grant configuration) for UE 10 at 222, and then UE 10 may transmit the periodic event-triggered LI measurement reports at 224.

[0065] Compared with procedure 200 shown in Fig. 2, procedure 200A can flexibly allocate UL resources for the periodic event-triggered LI measurement reporting at the expense of slightly increased overhead.

[0066] Fig. 4 illustrates an example of method 300 for periodic event-triggered LI measurement reporting. Method 300 may be implemented at a terminal device, e.g., UE 10discussed above.

[0067] Referring to Fig. 4, method 300 may comprise, 310, receiving configuration information for one or more periodic event-triggered LI measurement reporting from the network, e.g., base station 20. The configuration information for an event-triggered LI measurement reporting may comprise information associated with periodic LI measurement reporting upon certain measurement event(s) is triggered. For example, the configuration information may indicate one or more events which will trigger the periodic LI measurement reporting. UE 10 may detect only the events indicated in the configuration information, or if other events than those indicated in the configuration information are detected, UE 10 would not trigger the periodic LI measurement reporting. The configuration information may indicate an interval / periodicity of the periodic LI measurement reporting. The configuration information may also indicate the maximum number of LI measurement reports that are allowed to be transmitted once the corresponding event is triggered.

[0068] In an example, the configuration information for an event-triggered LI measurement reporting may comprise information indicating a periodic UL grant configuration configured for the periodic event trigger LI measurement reporting. For example, the configuration information may comprise the periodic UL grant configuration per se, or it may comprise information such as a configuration identifier (ID) referring to the periodic UL grant configuration, and the periodic UL grant configuration may be configured in a separate message(s). The periodic UL grant configuration may indicate time-domain and frequency-domain UL resources, interval / periodicity of the UL resources, the maximum number of LI measurement reports allowed to be transmitted on the periodic UL resources, among others, for the periodic LI measurement reporting.

[0069] In an example, the configuration information for an event-triggered LI measurement reporting may comprise one or more periodic UL grant configurations for the periodic LI measurement reporting. Each periodic UL grant configuration may be assigned with a configuration identifier (ID). The periodic UL grant configuration may be dedicated to / specific for event-triggered LI measurement reporting, or it may be used for transmission of other data or control information. In an example, the periodic UL grant configuration may be specific to LI measurement reporting triggered by a certain measurement event, and it may contain or be associated to an event ID of the corresponding measurement event. The periodic UL grant configuration may be active / usable once it is configured, or it may need to be activated before use.

[0070] Method 300 may comprise, 311, determining that a measurement event is triggered and,312, transmitting an indication to base station 20 indicating that the measurement event is triggered. For example, based on the configuration information, UE 10 may carry out LI measurements and evaluate whether a condition for a measurement event indicated in the configuration information is satisfied or not. If the condition is satisfied, UE 10 may determine at 311 that the measurement event is triggered and transmit an indication to base station 20 at 312 indicating that the measurement event is triggered.

[0071] At 314, UE 10 may receive from base station 20 a downlink (DL) control message containing a request for LI measurement reports associated with the indicated measurement event. The DL control message may indicate the measurement event for which the LI measurement reports are requested.

[0072] In an example, the DL control message may contain a first field Fl indicating whether a periodic UL grant configuration is activated for periodic transmission of the event-triggered LI measurement reports, and / or a second field Pl indicating whether the event-triggered LI measurement reports are requested to be transmitted in a periodic manner. The first field Fl may indicate the configuration ID of the periodic UL grant configuration to be activated. In an example, the periodic UL grant configuration to be activated may be specific for the periodic LI measurement reporting triggered by the measurement event UE 10 indicated to base station 20 at 312.

[0073] In an example, the second field Pl may be omitted, and the first field Fl may implicitly indicate the periodic transmission of the event-triggered LI measurement reports. For example, if the first field Fl indicates activation of a periodic UL grant configuration for the event- triggered LI measurement reporting, the event-triggered LI measurement reports will be transmitted in the periodic manner based on the activated periodic UL grant configuration. If the first field Fl does not indicate activation of any periodic UL grant configuration for the event- triggered LI measurement reporting, UE 10 may not transmit the event-triggered LI measurement reports in the periodic manner.

[0074] In an example, the first field Fl may be omitted. For example, activation of the periodic UL grant configuration may be determined at UE 10, or the periodic UL grant configuration does not need to be activated. In another example, the second field Pl may implicitly indicate the activation of the periodic UL grant configuration. For example, if the second field Pl indicates periodic transmission of the event-triggered LI measurement reports, UE 10 may interpret it as an implicit indication of activation of the periodic UL grant configuration for the periodic LI measurement reporting. If the second field Pl does not indicate periodic transmission of the event-triggered LI measurement reports, UE 10 may not activate any periodic UL grantconfiguration.

[0075] In an example, method 300 may comprise, 316, determining whether to activate the periodic UL grant configuration or not. For example, the DL control message received at 314 may not indicate whether to activate the periodic UL grant configuration or not, and instead UE 10 may determine whether to activate the periodic UL grant configuration or not. If the DL control message received at 314 has indicated activation of the periodic UL grant configuration, block 316 may be omitted.

[0076] In an example, UE 10 may determine activation of the periodic UL grant configuration based on the event-triggered LI measurement report to be transmitted. For example, UE 10 may determine activation of the periodic UL grant configuration based on TCI state and / or synchronization status of a reference signal (RS), a candidate beam or a candidate cell associated with the event-triggered LI measurement report. If at least one TCI state of the RS, the candidate beam or the candidate cell associated with the event-triggered LI measurement report is activated, and / or UE 10 has acquired UL synchronization with the RS, the candidate beam or the candidate cell associated with the event-triggered LI measurement report, UE 10 may decide to activate the periodic UL grant configuration for the periodic event-triggered LI measurement reporting. Otherwise, UE 10 may decide not to activate the periodic UL grant configuration. In another example, UE 10 may decide activation of the periodic UL grant configuration based on whether the UE has pre-processed the LTM candidate cell configuration or not. For example, if UE 10 has carried out early ASN.l decoding or / and validity check for configuration of a certain LTM candidate cell associated with an event-triggered LI measurement reporting before cell switch, UE 10 may decide to activate periodic UL grant configuration for the periodic event-triggered LI measurement reporting.

[0077] In an example, if UE 10 decides to activate a periodic UL grant configuration for the periodic event-triggered LI measurement reporting at 316, UE 10 may notify (not shown) base station 20 that the periodic UL grant configuration is activated.

[0078] If the DL control message received at 314 requests UE 10 to transmit the event-triggered LI measurement reports in the periodic manner, UE 10 may periodically transmit the event- triggered LI measurement reports to base station 20 at 318 based on the periodicity indicated in the configuration information received at 310. The periodic reports may be conveyed via uplink control information (UCI) or MAC CE. In an example, if a periodic UL grant configuration is available or activated for the event-triggered LI measurement reporting, UE 10 may transmit the periodic event-triggered LI measurement reports based on the periodic UL grant configuration. If the periodic UL grant configuration is also applicable for transmission of other data or controlinformation, UE 10 may prioritize the event-triggered LI measurement reports on the periodic UL resources associated with the periodic UL grant configuration.

[0079] UE 10 may continue to perform LI measurements and transmit the periodic event- triggered LI measurement reports at 318, as long as the condition for the event is satisfied. If the event condition becomes unmet, UE 10 may stop the periodic event-triggered LI measurement reporting. In an example, if the configuration information for the periodic event-triggered LI measurement reporting provisions the maximum number of reports allowed to be transmitted, UE 10 may stop the periodic reporting when the provisioned number of reports have been transmitted, or when the provisioned number of occasions of the periodic UL resources for the periodic event-triggered LI measurement reporting have elapsed regardless of whether the number of reports have been actually transmitted.

[0080] In an example, if the DL control message received at 314 requests the event-triggered L 1 measurement report but it does not request UE 10 to transmit the report in the periodic manner, UE 10 may transmit the event-triggered L 1 measurement report for one time at 318. For example, the DL control message received at 314 may contain a UL grant for the one-time transmission of the requested event-triggered LI measurement report. In another example, UE 10 may use resources allocated in the periodic UL grant configuration for the one-time transmission of the requested event-triggered LI measurement report. In yet another example, UE 10 may request base station 20 to allocate UL resources for the one-time transmission of the event-triggered LI measurement report.

[0081] Fig 5 illustrates another example of method 300 A for a periodic event-triggered LI measurement reporting that may be implemented at a terminal device, e.g., the UE 10 discussed above. Method 300A is a variant of method 300 discussed above with reference to Fig. 4, and it includes some same or similar blocks denoted with the same reference numerals. Here the description will focus on the different blocks, and a repetitive description for the same blocks is omitted.

[0082] Referring to Fig. 5, it is assumed that the DL control message received at 314 requests UE 10 to transmit the event-triggered LI measurement reports in the periodic manner, but neither base station 20 nor UE 10 activates any periodic UL grant configuration for the periodic event- triggered LI measurement reporting, or base station 20 does not configure the periodic UL grant configuration for UE 10. Method 300Amay include the following blocks for UE 10 to carry out periodic transmission of the requested event-triggered LI measurement reports.

[0083] At 320, UE 10 may transmit a request for UL resources for at least one transmission of the event-triggered LI measurement report to base station 20. For example, UE 10 may transmita scheduling request (SR), a new UCI type or an RACH preamble to request the UL resources.

[0084] At 322, UE 10 may receive a UL grant from base station 20. The UL grant carries information of UL resources allocated to UE 10.

[0085] Then UE 10 may transmit the event-triggered LI measurement report based on the UL grant at 324.

[0086] The method in blocks 320-324 may be repeatedly carried out for each periodic transmission of the event-triggered LI measurement reports, until, for example, the event condition becomes unmet, or the maximum limit set for the number of reports is met. In another example, if the DL control message received at 314 comprises a UL grant for UE 10, UE 10 may transmit the first LI measurement report based on the UL grant and then carry out the method in blocks 320-324 for each subsequent LI measurement report. In yet another example, base station 20 may configure periodic UL resources (e.g., by a periodic UL grant configuration) for UE 10 at 322, and UE 10 may transmit the periodic event-triggered LI measurement reports at 324.

[0087] Fig 6 is a schematic block diagram illustrating an example of apparatus 400. Apparatus 400 may be implemented to comprise or to form at least a part of a terminal device such as UE 10 discussed above. The blocks of apparatus 400 may be implemented with software, hardware, firmware or any combination thereof to perform at least a part of operations related to UE 10.

[0088] Referring to Fig. 6, apparatus 400 may comprise means 410 for receiving configuration information for one or more periodic event-triggered Layer 1 measurement reporting, means 411 for determine that a measurement event is triggered, and means 412 for transmitting an indication of the measurement event being triggered based on the configuration information. Means 410 may be configured to receive the configuration information from a network device, e.g., base station 20 discussed above. The configuration information for an event-triggered LI measurement reporting may comprise information associated with periodic LI measurement reporting upon certain measurement event(s) is triggered. For example, the configuration information may indicate one or more events that will trigger the periodic LI measurement reporting. Based on the configuration information, UE 10 may carry out LI measurements and evaluate whether conditions for the one or more events are satisfied or not. If any one of the event conditions is satisfied, means 411 may determine that the measurement event is triggered, and means 412 may transmit the indication to base station 20 indicating that the measurement event is triggered.

[0089] In an example, the configuration information for an event-triggered LI measurement reporting may include a parameter indicating an interval or periodicity of the periodic LI measurement reporting triggered by the measurement event. , The configuration information foran event-triggered LI measurement reporting may also comprise a parameter indicating the maximum number of LI measurement reports allowed to be transmitted once the corresponding event is triggered. Alternatively or additionally, the configuration information for an event- triggered LI measurement reporting may comprise information indicating a periodic UL grant configuration configured for the periodic event trigger LI measurement reporting. For example, the configuration information may comprise the periodic UL grant configuration per se, or it may comprise information such as a configuration identifier (ID) referring to the periodic UL grant configuration, and the periodic UL grant configuration may be configured in a separate message(s). The periodic UL grant configuration may configure, among others, time-domain and frequency-domain UL resources, interval / periodicity of the UL resources, and the maximum number of LI measurement reports allowed to be transmitted on the periodic UL resources, for the periodic event-triggered LI measurement reporting.

[0090] In an example, the configuration information for an event-triggered LI measurement reporting may configure one or more periodic UL grant configurations for UE 10. Each periodic UL grant configuration may be assigned with a configuration identifier (ID). The periodic UL grant configuration may be specific for event-triggered LI measurement reporting, or it may be used for transmission of other data or control information as well. In an example, the periodic UL grant configuration may be specific to LI measurement reporting triggered by a certain event, and it may contain or be associated to an event ID of the corresponding event. The periodic UL grant configuration may be active / usable once it is configured, or it may need to be activated before use.

[0091] Apparatus 400 may further comprise means 414 for receiving a downlink (DL) control message from base station 20. The DL control message may comprise a request for the LI measurement reports triggered by the measurement event UE 10 indicated to base station 20. In an example, the DL control message may comprise a first field Fl indicating whether a periodic UL grant configuration is activated for periodic transmission of the event-triggered LI measurement reports, and / or a second field Pl indicating whether the event-triggered LI measurement reports are requested to be transmitted in a periodic manner. In an example, the first field Fl may implicitly indicate the periodic transmission of the event-triggered LI measurement reports, and the second field Pl may be omitted. For example, if the first field Fl indicates activation of a periodic UL grant configuration for the event-triggered LI measurement reporting, the event-triggered LI measurement reports will be transmitted in the periodic manner based on the activated periodic UL grant configuration. If the first field Fl does not indicate activation of any periodic UL grant configuration for the event-triggered LI measurementreporting, UE 10 may not transmit the event-triggered LI measurement reports in the periodic manner. In an example, the first field Fl may be omitted. For example, activation of the periodic UL grant configuration may be determined at UE 10, the periodic UL grant configuration may not need to be activated, or the second field Pl may implicitly indicate the activation of the periodic UL grant configuration. For example, if the second field Pl indicates periodic transmission of the event-triggered LI measurement reports, UE 10 may interpret it as an implicit indication of activation of the periodic UL grant configuration for the periodic LI measurement reporting. If the second field Pl does not indicate periodic transmission of the event-triggered LI measurement reports, UE 10 may not activate any periodic UL grant configuration.

[0092] In an example, apparatus 400 may comprise means 416 for determining whether to activate a periodic UL grant configuration for the periodic event-triggered LI measurement reporting when for example the DL control message received from base station 20 does not indicate whether to activate the periodic UL grant configuration or not. Means 416 may determine activation of the periodic UL grant configuration based on the event-triggered LI measurement report to be transmitted. For example, means 416 may determine activation of the periodic UL grant configuration based on TCI state and / or UL synchronization status of a reference signal (RS), a candidate beam or a candidate cell associated with the event-triggered LI measurement report. If at least one TCI state of the RS, the candidate beam or the candidate cell associated with the event-triggered LI measurement report is activated, and / or the apparatus 400 has acquired UL synchronization with the RS, the candidate beam or the candidate cell associated with the event-triggered LI measurement report, means 416may decide to activate the periodic UL grant configuration for the periodic event-triggered LI measurement reporting. Otherwise, means 416 may decide not to activate the periodic UL grant configuration. In an example, means 416 may determine activation of the periodic UL grant configuration based on whether the apparatus 400 has pre-processed the LTM candidate cell configuration or not. For example, if apparatus 400 has carried out early ASN.l decoding or / and validity check for configuration of a certain LTM candidate cell associated with an event-triggered LI measurement reporting before cell switch, means 416 may decide to activate the periodic UL grant configuration for the periodic event-triggered LI measurement reporting.

[0093] Apparatus 400 may comprise means 418 for transmitting the periodic event-triggered LI measurement reports to base station 20 based on the periodicity indicated in the configuration information received from base station 20. The periodic reports may be conveyed via uplink control information (UCI) or MAC CE. In an example, if a periodic UL grant configuration is available or activated for the event-triggered L 1 measurement reporting, means 418 may transmitthe periodic event-triggered LI measurement reports based on the periodic UL grant configuration. If the periodic UL grant configuration is also applicable for transmission of other data or control information, means 418 may prioritize the event-triggered LI measurement report transmission on the periodic UL resources associated with the periodic UL grant configuration.

[0094] Means 418 may be configured to periodically transmit the event-triggered LI measurement reports as long as the condition for the measurement event is satisfied. If the event condition becomes unmet, the transmission of the periodic event-triggered LI measurement reports may be ended. In an example, if the configuration information for the periodic event- triggered LI measurement reporting provisions the maximum number of reports allowed to be transmitted, the periodic reporting may be stopped when the maximum number of the reports have been transmitted, or when the maximum number of occasions of the periodic UL resources for the periodic event-triggered LI measurement reporting have elapsed regardless of whether the number of reports have been actually transmitted.

[0095] In an example, if the DL control message received at means 414 requests the event- triggered LI measurement report but it does not indicate periodic transmission, means 418 may transmit the event-triggered LI measurement report for one time. In an example, the DL control message may comprise a UL grant for the one-time transmission of the requested event-triggered LI measurement report. In another example, means 418 may use UL resources allocated in the periodic UL grant configuration for the one-time transmission of the requested event-triggered LI measurement report. In yet another example, means 418 may request base station 20 to allocate UL resources for the one-time transmission of the event-triggered LI measurement report.

[0096] In an example, means 418 may comprise means 420 for requesting base station 20 to allocate UL resources for at least one transmission of the event-triggered LI measurement report. If the DL control message received at means 414 requests periodic transmission of the event- triggered LI measurement reports, but no periodic UL grant configuration is available or activated for the periodic event-triggered LI measurement reporting, means 420 may transmit the resource request to base station 20. The resource request may be a scheduling request (SR), a new UCI type, or a random access channel (RACH) preamble transmission.

[0097] Means 418 may further comprise means 422 for receiving a UL grant from base station 20, and means 424 for transmitting the event-triggered LI measurement report based on the UL grant.

[0098] In an example, means 420-424 may repeatedly carry out the above operations for each periodic transmission of the event-triggered LI measurement reports, until for example the eventcondition becomes unmet or the maximum limit set for the number of LI measurement reports is met. In another example, if the DL control message received at means 414 comprises a UL grant, the first LI measurement report may be transmitted based on the UL grant and then the means 420-424 may carry out the above operations for each subsequent LI measurement report. In yet another example, means 422 may receive a periodic UL grant configuration from base station 20, and means 424 may transmit the periodic event-triggered LI measurement reports based on the periodic UL grant configuration.

[0099] Fig 7 is a schematic flowchart illustrating an example of method 500 for collecting periodic event-triggered LI measurement reports. Method 500 may be implemented at a network device, e.g., base station 20 discussed above.

[0100] Referring to Fig. 7, method 500 may comprise, 510, transmitting configuration information for one or more periodic event-triggered LI measurement reporting to a terminal device e.g. UE 10 discussed above. The configuration information for an event-triggered LI measurement reporting may comprise information associated with periodic LI measurement reporting upon certain measurement event(s) is triggered. For example, the configuration information may indicate one or more events which will trigger the periodic LI measurement reporting. If UE 10 detects a condition for any of the indicated events is satisfied, UE 10 may trigger the periodic LI measurement reporting. The configuration information may indicate an interval / periodicity of the periodic LI measurement reporting. The configuration information may also indicate the maximum number of LI measurement reports allowed to be transmitted once the corresponding event is triggered.

[0101] In an example, the configuration information for an event-triggered LI measurement reporting may comprise information indicating one or more periodic UL grant configurations configured for the periodic event trigger LI measurement reporting. Each periodic UL grant configuration may be assigned with a configuration identifier (ID). The periodic UL grant configuration may indicate time-domain and frequency-domain UL resources, interval / periodicity of the UL resources, the maximum number of LI measurement reports allowed to be transmitted on the periodic UL resources, among others, for the periodic LI measurement reporting. The periodic UL grant configuration may be specific for event-triggered LI measurement reporting, or it may be also applicable for transmission of other data or control information. In an example, the periodic UL grant configuration may be specific to LI measurement reporting triggered by a certain measurement event, and it may contain or be associated to an event ID of the corresponding event. The periodic UL grant configuration may be active / usable once it is configured, or it may need to be activated before use.

[0102] At 512, base station 20 may receive an indication from UE 10 indicating that a measurement event is triggered at UE 10. The event was indicated in the configuration information transmitted to UE 10 at 510.

[0103] In response to the event indication, base station 20 may transmit a downlink (DL) control message requesting LI measurement reports triggered by the indicated event to UE 10 at 514. In an example, the DL control message may contain a first field Fl indicating whether a periodic UL grant configuration is activated for periodic transmission of the event-triggered LI measurement reports, and / or a second field Pl indicating whether the event-triggered LI measurement reports are requested to be transmitted in a periodic manner. The first field Fl may indicate the configuration ID of the periodic UL grant configuration to be activated. In an example, the periodic UL grant configuration to be activated may be specific for the periodic LI measurement reporting triggered by the measurement event UE 10 indicated to base station 20 at 512.

[0104] In an example, the first field Fl may (implicitly) indicate the periodic transmission of the requested event-triggered LI measurement reports, and the second field Pl may be omitted. For example, if the first field Fl indicates activation of a periodic UL grant configuration for the event-triggered LI measurement reporting, the event-triggered LI measurement reports will be transmitted in the periodic manner based on the activated periodic UL grant configuration. If the first field Fl does not indicate activation of any periodic UL grant configuration for the event- triggered LI measurement reporting, UE 10 is not requested to transmit the event-triggered LI measurement reports in the periodic manner.

[0105] In an example, the first field Fl may be omitted. For example, activation of the periodic UL grant configuration may be determined at UE 10, or the periodic UL grant configuration does not need to be activated. In another example, the second field Pl may (implicitly) indicate the activation of the periodic UL grant configuration. For example, if the second field Pl indicates periodic transmission of the event-triggered LI measurement reports, it may be interpreted as an implicit indication of activation of the periodic UL grant configuration for the periodic LI measurement reporting. If the second field Pl does not indicate periodic transmission of the event-triggered LI measurement reports, it may be interpreted as an indication that no periodic UL grant configuration is activated.

[0106] In an example, the DL control message transmitted at 514 may not indicate whether to activate the periodic UL grant configuration or not. Instead, activation of the periodic UL grant configuration may be determined at UE 10.

[0107] If the DL control message transmitted at 514 requests UE 10 to transmit the event-triggered LI measurement reports in the periodic manner, base station 20 may receive the periodic event-triggered LI measurement reports from UE 10 at 516 based on the periodicity indicated in the configuration information transmitted to UE 10 at 510. The periodic reports may be received in uplink control information (UCI) or MAC CE. In an example, if a periodic UL grant configuration is available or activated for the event-triggered LI measurement reporting, base station 20 may receive the periodic event-triggered LI measurement reports from UE 10 based on the periodic UL grant configuration. In an example, if the configuration information for the periodic event-triggered LI measurement reporting provisions the maximum number of reports allowed to be transmitted, base station 20 may stop receiving the periodic event-triggered LI measurement reports when the maximum limit set for the number of reports is met, or when the maximum number of occasions of the periodic UL resources for the periodic event-triggered LI measurement reporting have elapsed.

[0108] In an example, if the DL control message transmitted at 514 requests the event-triggered L 1 measurement report but it does not request UE 10 to transmit the report in the periodic manner, base station 20 may receive the event-triggered LI measurement report for one time at 518. For example, the DL control message may comprise a UL grant for the one-time transmission of the requested event-triggered LI measurement report. In another example, base station 20 may receive the one-time transmission of the requested event-triggered LI measurement report on resources allocated in the periodic UL grant configuration. In yet another example, base station 20 may allocate UL resources for the one-time transmission of the event-triggered LI measurement report in response to a resource request received from UE 10.

[0109] Fig 8 illustrates another example of method 500A for collecting periodic event- triggered LI measurement reports that may be implemented at base station 20. Method 500Ais a variant of method 500 discussed above with reference to Fig. 7, and it includes some same or similar blocks denoted with the same reference numerals. Here the description will focus on the different blocks, and a repetitive description for the same blocks is omitted.

[0110] Referring to Fig. 8, it is assumed that the DL control message transmitted to UE 10 at 514 requests UE 10 to transmit the event-triggered LI measurement reports in the periodic manner, but no periodic UL grant configuration is available or activated for the periodic event- triggered LI measurement reporting. In this case, method 500Amay include the following blocks for base station 20 to receive the periodic event-triggered LI measurement reports at 516.

[0111] At 518, base station 20 may receive a request for UL resources for at least one transmission of the event-triggered LI measurement report. In some examples, the UL resource request may comprise a scheduling request (SR), a new UCI type, or an RACH preambletransmission.

[0112] In response to the resource request, base station 20 may allocate UL resources for UE 10 and transmit a UL grant to UE 10 at 520.

[0113] At 522, base station 20 may receive the event-triggered LI measurement report based on the UL grant.

[0114] In an example, the blocks 518-522 may be repeatedly carried out for each periodic transmission of the event-triggered LI measurement reports, until for example the number of the received reports reaches the maximum limit set in the configuration information for the periodic event-triggered LI measurement reporting. In another example, the DL control message transmitted at 514 may comprise a UL grant for UE 10, base station 20 may receive the first LI measurement report based on the UL grant and then carry out blocks 518-522 for each subsequent LI measurement report. In yet another example, base station 20 may configure periodic UL resources (e.g., by a periodic UL grant configuration) for UE 10 at 520 and then receive the periodic event-triggered LI measurement reports on the periodic UL resources. It can reduce the signaling overhead.

[0115] Fig 9 is a schematic block diagram illustrating an example of apparatus 600. Apparatus 600 may be implemented to comprise or to form at least a part of a network device such as base station 20 discussed above. The blocks of apparatus 600 may be implemented with software, hardware, firmware or any combination thereof to perform at least a part of operations related to base station 20.

[0116] Referring to Fig. 9, apparatus 600 may comprise means 610 for transmitting configuration information for one or more periodic event-triggered LI measurement reporting to a terminal device e.g. UE 10 discussed above. The configuration information for an event- triggered LI measurement reporting may comprise information associated with periodic LI measurement reporting upon certain measurement event(s) is triggered. For example, the configuration information may indicate one or more measurement events which will trigger the periodic LI measurement reporting. If any of the indicated events is detected at UE 10, UE 10 may trigger the periodic LI measurement reporting. The configuration information may indicate an interval / periodicity of the periodic LI measurement reporting. In an example, the configuration information may also indicate the maximum number of LI measurement reports allowed to be transmitted once the corresponding event is triggered.

[0117] In an example, the configuration information for an event-triggered LI measurement reporting may comprise information indicating one or more periodic UL grant configurations configured for the periodic event trigger LI measurement reporting. Each periodic UL grantconfiguration may be assigned with a configuration identifier (ID). The periodic UL grant configuration may indicate time-domain and frequency-domain UL resources, interval / periodicity of the UL resources, the maximum number of LI measurement reports allowed to be transmitted on the periodic UL resources, among others, for the periodic LI measurement reporting. The periodic UL grant configuration may be specific for event-triggered LI measurement reporting, or it may be also applicable for transmission of other data or control information. In an example, the periodic UL grant configuration may be specific to LI measurement reporting triggered by a certain event, and it may contain or be associated to an event ID of the corresponding event. The periodic UL grant configuration may be active / usable once it is configured, or it may need to be activated before use.

[0118] Apparatus 600 may comprise means 612 for receiving an indication from UE 10 indicating that a measurement event is triggered, and means 614 for transmitting a downlink (DL) control message to UE 10 in response to the event indication. The DL control message may request UE 10 to transmit LI measurement reports associated with the indicated event. In an example, the DL control message may comprise a first field Fl indicating whether a periodic UL grant configuration is activated for periodic transmission of the event-triggered LI measurement reports, and / or a second field Pl indicating whether the event-triggered LI measurement reports are requested to be transmitted in a periodic manner. The first field Fl may indicate the configuration ID of the periodic UL grant configuration to be activated. In an example, the periodic UL grant configuration to be activated may be specific for the periodic LI measurement reporting triggered by the measurement event.

[0119] In an example, the first field Fl may (implicitly) indicate the periodic transmission of the requested event-triggered LI measurement reports, and the second field Pl may be omitted. For example, if the first field Fl indicates activation of a periodic UL grant configuration for the event-triggered LI measurement reporting, it implies that the event-triggered LI measurement reports will be transmitted in the periodic manner based on the activated periodic UL grant configuration. If the first field Fl does not indicate activation of any periodic UL grant configuration for the event-triggered LI measurement reporting, it implies that the event- triggered LI measurement reports are not requested to be transmitted in the periodic manner.

[0120] In an example, the first field Fl may be omitted. For example, activation of the periodic UL grant configuration may be determined at UE 10, or the periodic UL grant configuration does not need to be activated. In another example, the second field Pl may (implicitly) indicate the activation of the periodic UL grant configuration. For example, if the second field Pl indicates periodic transmission of the event-triggered LI measurement reports, it may be interpreted as animplicit indication of activation of the periodic UL grant configuration for the periodic LI measurement reporting. If the second field Pl does not indicate periodic transmission of the event-triggered LI measurement reports, it may be interpreted as an indication that no periodic UL grant configuration is activated.

[0121] In an example, the DL control message transmitted by means 614 may not indicate whether to activate the periodic UL grant configuration or not. Instead, activation of the periodic UL grant configuration may be determined at UE 10.

[0122] Apparatus 600 may comprise means 616 for receiving the periodic event-triggered LI measurement reports based on the periodicity indicated in the configuration information, if the DL control message requests the periodic event-triggered LI measurement reports. Means 616 may receive the periodic reports via uplink control information (UCI) or MAC CE. In an example, if a periodic UL grant configuration is available or activated for the event-triggered LI measurement reporting, means 616 may receive the periodic event-triggered LI measurement reports on periodic UL resources assigned by the periodic UL grant configuration. In an example, if the configuration information for the periodic event-triggered LI measurement reporting provisions the maximum number of reports allowed to be transmitted, means 616 may stop receiving the periodic event-triggered LI measurement reports when the maximum limit set for the number of reports is met, or when the maximum number of occasions of the periodic UL resources for the periodic event-triggered LI measurement reporting have elapsed.

[0123] In an example, if the DL control message transmitted by means 614 requests the event- triggered LI measurement report but it does not request UE 10 to transmit the report in the periodic manner, means 616 may receive the event-triggered LI measurement report for one time. For example, the DL control message may comprise a UL grant for the one-time transmission of the requested event-triggered LI measurement report. In another example, means 616 may receive the one-time transmission of the requested event-triggered LI measurement report on resources allocated in the periodic UL grant configuration. In yet another example, means 616 may transmit the event-triggered LI measurement report on UL resources allocated to UE 10 in a separate message, e.g., in response to a resource request received from UE 10.

[0124] In an example, means 616 may comprise means 618 for receiving from UE 10 a request for UL resources for at least one transmission of the event-triggered LI measurement report, and means 620 for transmitting a UL grant to UE 10 in response to the UL resource request. The UL resource request may comprise a scheduling request (SR), a new UCI type, or an RACH preamble transmission. The UL grant may allocate UL resources for UE 10 to transmit the event- triggered LI measurement report.

[0125] Means 616 may comprise means 622 for receiving the event-triggered LI measurement report based on the UL grant.

[0126] In an example, means 618-622 may carry out the above operations repeatedly for each periodic transmission of the event-triggered LI measurement reports, until for example the number of the received reports reaches the maximum limit set for the number of reports in the configuration information for the periodic event-triggered LI measurement reporting. In another example, the DL control message transmitted by means 614 may comprise a UL grant for UE 10, the first LI measurement report may be received based on the UL grant and then means 618-622 may carry out the above operations for each subsequent LI measurement report. In yet another example, means 620 may configure periodic UL resources (e.g., by a periodic UL grant configuration) for UE 10 and then means 622 may receive the periodic event-triggered LI measurement reports on the periodic UL resources. It can reduce the signaling overhead.

[0127] Examples of enabling periodic event-triggered LI measurement reporting have been described above. As discussed above, UE 10 may keep to periodically transmit the event- triggered LI measurement reports as long as the event condition is satisfied. However, it may increase the overhead of the system. In some use cases, the periodic LI measurement reporting may become useless or undesirable in case for example some conditions, status or environment change. Some examples provide example methods for deactivating the periodic LI measurement reporting, which are discussed below.

[0128] Fig 10 is a schematic message flow diagram illustrating an example of procedure 700 of deactivating periodic event-triggered LI measurement reporting. Procedure 700 may be applied in an LTM procedure, a beam management procedure, or other procedures where periodic event-triggered LI measurement reporting is carried out.

[0129] Referring to Fig. 10, at 710, UE 10 may transmit periodic event-triggered LI measurement reports on periodic UL resources associated with periodic event-triggered LI measurement reporting to base station 20 after the associated event is met. For example, UE 10 may transmit the periodic LI measurement reports based on a period UL grant configuration allocating the periodic UL resources for the periodic reporting. Since the periodic transmission of the event-triggered LI measurement reports has been described above, a repetitive description thereof is omitted here for convenience.

[0130] At 712, UE 10 may deactivate the periodic transmission of the event-triggered LI measurement reports if a predefined condition is fulfilled. In an example, UE 10 may also deactivate the periodic UL resources for the periodic LI measurement reporting at 714 if the predefined condition is fulfilled. UE 10 may deactivate the periodic LI measurement reportingonly, or deactivate both the periodic LI measurement reporting and the periodic UL resources for the periodic LI measurement reporting. For example, if the periodic UL resources are specific for the periodic LI measurement reporting, UE 10 may deactivate both the periodic LI measurement reporting and the periodic UL resources. If the periodic UL resources are also applicable for transmissions of other data or control information, UE 10 may deactivate only the periodic LI measurement reporting and maintain the periodic UL resources active.

[0131] In some examples, UE 10 may deactivate the periodic LI measurement reporting and optionally the periodic UL resources for the periodic LI measurement reporting in response to an indication received from base station 20. For example, base station 20 may send to UE 10 an indication indicating deactivation of a configuration for the periodic LI measurement reporting, and / or an indication indicating deactivation of a periodic UL grant configuration allocating the periodic UL resources for the periodic LI measurement reporting.

[0132] If base station 20 instructs UE 10 to deactivate the periodic LI measurement reporting, UE 10 may deactivate only the periodic LI measurement reporting, but the periodic UL resources may be still active for example for transmission of other data of control information, or for transmission of LI measurement reports triggered by other measurement events that base station 20 does not instruct UE 10 to deactivate. If base station 20 instructs UE 10 to deactivate the periodic UL resources, UE 10 may deactivate the periodic UL resources and the periodic LI measurement reporting on the periodic UL resources.

[0133] In an example, the indication to deactivate periodic LI measurement reporting of an event-triggered reporting may be received in a downlink control message. The downlink control message may be a DCI or MAC-CE message. In some examples, a field may be used to inform about the deactivation of the periodic LI measurement reporting. When the value of the field is set to a first value, e.g., “0”, it may indicate that the periodic LI measurement reporting or / and periodic UL resources associated with the periodic LI measurement reporting are deactivated, and when the field is set to a second value, e.g., “1” it may indicate no change in the reporting configuration. In an example, the field provisioning the UL resource allocation associated with an event-triggered reporting (and that may have triggered periodic reporting) may be used to deactivate the periodic reporting or / and the periodic UL resources if the periodic reporting is active. For example, a field which is used to activate or trigger the periodic reporting may be used also to deactivate the active periodic LI measurement reporting or / and the periodic UL resources. For example, when UE receives the field the first time, UE will activate the periodic reporting in response to the field; when UE receives the field the second time, UE will deactivate the periodic reporting in response to the field. In some examples, the downlink control messagemay contain a field indicating the information of the event or event-triggered reporting for which the periodic LI measurement reporting needs to be deactivated.

[0134] In an example, UE 10 may deactivate the periodic LI measurement reporting for an event-triggered LI measurement reporting and optionally the periodic UL resources when UE 10 receives from base station 20 an indication to deactivate at least one TCI state of a reference signal (RS), a candidate beam or a candidate cell associated with the event-triggered LI measurement reporting, or an indication to activate at least one TCI state of an RS, a candidate beam or a candidate cell different from the RS, the candidate beam or the candidate cell associated with the event-triggered LI measurement reporting, or a PDCCH order triggering an RACH preamble transmission towards a candidate cell different from the candidate cell associated with the event-triggered LI measurement reporting.

[0135] For example, in the LTM procedure, base station 20 can configure multiple candidate cells for UE 10 and select at least one of them as a target candidate cell. Base station 20 can activate at least one TCI state of the target candidate cell or a reference signal (RS) or beam of the target candidate cell in advance before the target candidate cell becomes the serving cell, which allows UE 10 to be DL synchronized with the target candidate cell. UE 10 may also be UL synchronized with the target candidate cell through an early TA acquisition procedure. The early TA acquisition procedure may be triggered by PDCCH order or realized through UE-based TA measurement. In the former case, in response to the PDCCH order received from the serving cell, UE 10 transmits an RACH preamble to the candidate cell, but UE 10 does not receive random access response (RAR) from the candidate cell for the purpose of TA value acquisition. The base station to which the candidate cell belongs calculates the TA value and sends it to base station 20 to which the serving cell belongs, and the serving cell sends the TA value in the LTM cell switch command MAC CE to UE 10 when triggering LTM cell switch. Since UE 10 is DL and UL synchronized with the target candidate cell, a faster cell switch can be performed when the cell switch is triggered to the target candidate cell.

[0136] If UE 10 receives from base station 20 the indication to deactivate at least one TCI state of the RS, the candidate beam or the candidate cell associated with the event-triggered LI measurement reporting, UE 10 can interpret it as an implication that the candidate cell is not selected as a target candidate cell and there is small possibility of cell switch to the candidate cell. Therefore, UE 10 may decide to deactivate the periodic LI measurement reporting associated with the candidate cell and optionally the periodic UL resources for the event- triggered LI measurement reporting. Each cell may be configured with more than one RSs or beams. If base station 20 deactivates the TCI state of an RS or beam of the candidate cell differentfrom the RS or beam of the candidate cell for which the event-triggered LI measurement reporting is triggered, UE 10 may also deactivate the periodic LI measurement reporting associated with the candidate cell and optionally the periodic UL resources for the event- triggered LI measurement reporting.

[0137] In some LTM use cases, base station 20 may select only one of the candidate cells as the target candidate cell. If UE 10 receives from base station 20 an indication to activate at least one TCI state of an RS, a candidate beam or a candidate cell different from the RS, the candidate beam or the candidate cell associated with the event-triggered LI measurement reporting, or a PDCCH order triggering an RACH preamble transmission towards a candidate cell different from the candidate cell associated with the event-triggered LI measurement reporting, UE 10 may interpret the TCI state activation indication or the PDCCH order as an implication that a new candidate cell is selected as the target candidate cell, and the candidate cell associated with the event-triggered LI measurement reporting is not selected as the target candidate cell any longer. Therefore, UE 10 may decide to deactivate the periodic LI measurement reporting associated with the candidate cell and optionally the periodic UL resources for the event- triggered LI measurement reporting.

[0138] In an example, UE 10 may decide to deactivate the periodic LI measurement reporting and optionally the periodic UL resources for the event-triggered LI measurement reporting when UE 10 receives a cell switch command from base station 20. UE 10 will switch to a new serving cell indicated in the cell switch command, and the base station to which the new serving cell belongs may configure new event-triggered reporting configurations for UE 10.

[0139] In some examples, UE 10 may deactivate the periodic LI measurement reporting and optionally the periodic UL resources for the periodic LI measurement reporting based on one or more conditions determined at UE 10.

[0140] In an example, when UE 10 decides to deactivate at least one TCI state of the RS, the candidate beam or the candidate cell associated with the periodic LI measurement reporting, UE 10 may deactivate the periodic LI measurement reporting and optionally the periodic UL resources for the event-triggered LI measurement reporting. For example, UE 10 may decide to deactivate at least one TCI state of the RS, the candidate beam or the candidate cell based on the LI measurements of the RS, the candidate beam or the candidate cell. If the LI measurements show that quality of RS, the candidate beam or the candidate cell becomes worse than an absolute threshold or an amount of offset worse than another candidate cell or an RS or beam of the another candidate cell or the current serving cell, UE 10 may determine that the candidate cell is not selected as the target candidate cell any longer and the TCI state of the RS, the candidatebeam or the candidate cell is deactivated. Therefore, UE 10 may decide to deactivate the periodic LI measurement reporting associated with the candidate cell and optionally the periodic UL resources for the event-triggered LI measurement reporting.

[0141] In an example, when UE 10 decides to trigger or initiate UL synchronization with an RS, a candidate beam or a candidate cell different from the RS, the candidate beam or the candidate cell associated with the event-triggered LI measurement reporting, UE 10 may deactivate the periodic LI measurement reporting and optionally the periodic UL resources for the event-triggered LI measurement reporting. As discussed above, in a case where only one candidate cell is selected as the target candidate cell, UE’s synchronization with a new candidate cell implies that the new candidate cell is selected as the target candidate cell, and the candidate cell associated with the event-triggered LI measurement reporting is not selected as the target candidate cell any longer. Therefore, UE 10 may decide to deactivate the periodic LI measurement reporting associated with the candidate cell and optionally the periodic UL resources for the event-triggered LI measurement reporting.

[0142] In an example, when UE 10 declares beam failure with the candidate beam or the candidate cell associated with the event-triggered LI measurement reporting, UE 10 may decide to deactivate the periodic LI measurement reporting and optionally the periodic UL resources for the event-triggered LI measurement reporting.

[0143] In some examples, the UE 10 may deactivate the periodic LI measurement reporting and optionally the periodic UL resources for the periodic LI measurement reporting based on the LI measurement results obtained at UE 10. For example, if the LI measurement results show that the candidate cell associated with the event-triggered LI measurement reporting becomes not suitable for being selected as the target candidate cell, UE 10 may decide to deactivate the periodic LI measurement reporting associated with the candidate cell and optionally the periodic UL resources for the event-triggered LI measurement reporting.

[0144] In an example, UE 10 may determine that the candidate cell is not suitable for being selected as the target candidate cell if the LI measurement results show at least one of the following conditions:- quality of the RS, the candidate beam or the candidate cell becomes below a threshold,- difference between quality of the RS, the candidate beam or the candidate cell and quality of a serving cell RS, a serving cell indicated beam or the serving cell becomes below a threshold, or- quality of the serving cell or the serving cell indicated beam becomes above a threshold.

[0145] The above conditions / measurement results are described by way of example, and otherconditions / measurement results may also be used to determine whether the candidate cell is suitable for being selected as the target candidate cell or not. If the candidate cell is not suitable for being selected as the target candidate cell, UE 10 may decide to deactivate the periodic LI measurement reporting associated with the candidate cell and optionally the periodic UL resources for the event-triggered LI measurement reporting.

[0146] As discussed above, base station 20 may define the maximum number of periodic LI measurement reports allowed to be transmitted once the corresponding event is triggered. In an example, UE 10 may decide to deactivate the periodic LI measurement reporting and optionally the periodic UL resources for the event-triggered LI measurement reporting when the maximum limit set for the number of the periodic LI measurement reports is met, or when the maximum number of occasions of the periodic UL resources for the periodic event-triggered LI measurement reporting have elapsed regardless of whether the number of reports have been actually transmitted.

[0147] In an example, base station 20 may schedule non-event based LI measurement reporting, e.g., a periodic or semi-persistent CSI reporting, for a candidate cell or an RS / beam of a candidate cell. If UE 10 receives from base station 20 an indication to activate the non-event based LI measurement reporting (e.g., the periodic or semi-persistent CSI reporting) for a candidate cell or an RS / beam of a candidate cell associated with the event-triggered LI measurement reporting, UE 10 may decide to deactivate the periodic LI measurement reporting and optionally the periodic UL resources for the event-triggered LI measurement reporting.

[0148] In an example, when UE 10 decides to pre-process the candidate cell configuration of a candidate cell different from the candidate cell associated with the event-triggered LI measurement reporting, UE 10 may deactivate the periodic LI measurement reporting and optionally the periodic UL resources for the event-triggered LI measurement reporting. The preprocessing refers ASN.l decoding or / and validity check of the candidate cell configuration before cell switch.

[0149] Some example conditions have been described above for triggering deactivation of the periodic LI measurement reporting and optionally the periodic UL resources for the event- triggered LI measurement reporting. The example embodiments are not limited in any way to the example conditions described above, and other conditions may also be used as a trigger for deactivation of the periodic LI measurement reporting and optionally the periodic UL resources for the event-triggered LI measurement reporting.

[0150] With reference to Fig. 10, at 716, UE 10 may send a notification of the deactivation to base station 20. The notification may indicate that UE 10 has deactivated the periodic LImeasurement reporting, or both the periodic LI measurement reporting and the periodic UL resources for an event-triggered LI measurement reporting. The notification may be sent in an uplink control information or in a MAC-CE or in an RRC message. In some examples, base station 20 may know the deactivation of the periodic LI measurement reporting and the periodic UL resources, and block 716 may be omitted. For example, if UE 10 performs the deactivation based on an indication or message received from base station 20 as discussed above, base station 20 would also know the deactivation.

[0151] At 718, base station 20 may stop receiving the periodic event-triggered LI measurement reports when a predetermined condition is fulfilled. In an example, base station 20 may also deactivate the periodic UL resources for the periodic event-triggered LI measurement reports at 720 when the predetermined condition is fulfilled. For example, if the periodic UL resources are specific for the periodic LI measurement reporting, base station 20 may deactivate the periodic UL resources when it stops receiving the periodic LI measurement reports. If the periodic UL resources are also applicable for transmissions of other data or control information, base station 20 may stop receiving the periodic LI measurement reports but maintain the periodic UL resources active.

[0152] In an example, base station 20 may decide to stop receiving the periodic event-triggered LI measurement reports and optionally deactivate the periodic UL resources in response to the notification received from UE 10 at 716.

[0153] In an example, as discussed above, UE 10 may deactivate the periodic LI measurement reporting and the periodic UL resources in response to an indication received from base station 20. Hence base station 20 may stop receiving the periodic event-triggered LI measurement reports and optionally deactivate the periodic UL resources when it transmits the indication to UE 10. For example, base station 20 may stop receiving the periodic event-triggered LI measurement reports and optionally deactivate the periodic UL resources when at least one of the following indications is transmitted to UE 10:- an indication to deactivate the periodic event-triggered LI measurement reporting, which may be associated with a configuration for event-triggered LI measurement reporting;- an indication to deactivate the periodic UL resources for an event-triggered LI measurement reporting, which may be associated with a periodic UL grant configuration allocating the periodic UL resources;- an indication to deactivate at least one TCI state of a candidate cell or an RS / beam of the candidate cell associated with the event-triggered LI measurement reporting;- an indication to activate at least one TCI state of an RS / beam or candidate cell different fromthe RS / beam or candidate cell associated with the event-triggered LI measurement reporting;- a PDCCH order triggering an RACH preamble transmission towards a candidate cell different from the candidate cell associated with the event-triggered LI measurement reporting; or- a cell switch command.

[0154] As the above-listed example indications / messages have been discussed in the above description, a redundant description thereof is omitted here for convenience. The example embodiments are not limited in any way to the example indications / messages described above, and other indications / messages may also be used as a trigger for base station 20 to stop receiving the periodic LI measurement reports and optionally deactivate the periodic UL resources for the event-triggered LI measurement reporting.

[0155] In an example, as discussed above, base station 20 may define, for example in the configuration for the periodic event-triggered LI measurement reporting, the maximum number of periodic LI measurement reports allowed to be transmitted once the corresponding event is triggered. Then base station 20 may decide to stop receiving the periodic LI measurement reports and optionally deactivate the periodic UL resources for the event-triggered LI measurement reporting when the number of periodic LI measurement reports received from UE 10 reaches the maximum limit set in the configuration information, or when the maximum number of occasions of the periodic UL resources for the periodic event-triggered LI measurement reporting have elapsed regardless of whether the maximum number of reports have been actually received.

[0156] In an example, base station 20 may schedule non-event based LI measurement reporting, e.g., a periodic or semi-persistent CSI reporting, for a candidate cell or an RS / beam of the candidate cell. If base station 20 schedules the non-event based LI measurement reporting for an RS / beam or candidate cell associated with the event-triggered LI measurement reporting and informs UE 10 to activate the scheduled non-event based LI measurement reporting, base station 20 may decide to stop receiving the periodic LI measurement reports and optionally deactivate the periodic UL resources for the event-triggered LI measurement reporting.

[0157] It is worth of noting that in procedure 700, base station 20 and UE 10 would have a common understanding of states of the periodic LI measurement reporting and the periodic UL resources to ensure proper transmitting and receiving of the periodic LI measurement reports on the periodic UL resources. If necessary, additional signaling may be used to make sure that base station 20 and UE 10 can align their understanding to each other.

[0158] Fig 11 is a schematic flowchart illustrating an example of method 800 for deactivatingthe periodic event-triggered LI measurement reporting. Method 800 may be implemented at a terminal device, e.g., UE 10 discussed above.

[0159] Referring to Fig. 11, method 800 may comprise, 810, transmitting periodic event- triggered LI measurement reports to a network device e.g. base station 20 discussed above after the associated event is met. The periodic event-triggered LI measurement reports may be transmitted on periodic UL resources associated with an event-triggered LI measurement reporting. For example, UE 10 may transmit the periodic LI measurement reports based on a period UL grant configuration allocating the periodic UL resources for the event-triggered LI measurement reporting.

[0160] Method 800 may comprise, 812, deactivating the periodic event-triggered LI measurement reporting if a predefined condition is fulfilled, and optionally, 814, deactivating the periodic UL resources for the event-triggered LI measurement reporting in response to the predefined condition being fulfilled. UE 10 may deactivate the periodic LI measurement reporting only, or deactivate both the periodic LI measurement reporting and the periodic UL resources for the event-triggered LI measurement reporting. For example, if the periodic UL resources are specific for the periodic LI measurement reporting, UE 10 may deactivate both the periodic LI measurement reporting and the periodic UL resources. If the periodic UL resources are also applicable for transmissions of other data or control information, UE 10 may deactivate only the periodic LI measurement reporting and maintain the periodic UL resources active.

[0161] In some examples, UE 10 may deactivate the periodic LI measurement reporting and optionally the periodic UL resources for the event-triggered LI measurement reporting in response to an indication received from base station 20. For example, base station 20 may send to UE 10 an indication indicating deactivation of a configuration for the event-triggered LI measurement reporting, and / or an indication indicating deactivation of a periodic UL grant configuration allocating the periodic UL resources for the event-triggered LI measurement reporting.

[0162] In an example, the indication to deactivate periodic LI measurement reporting of an event-triggered reporting may be received in a downlink control message. The downlink control message may be a DCI or MAC-CE message. In some examples, a field may be used to inform about the deactivation of the periodic LI measurement reporting. When the value of the field is set to a first value, e.g., “0”, it may indicate that the periodic LI measurement reporting or / and periodic UL resources associated with the periodic LI measurement reporting are deactivated, and when the field is set to a second value, e.g., “1” it may indicate no change in the reportingconfiguration. In an example, the field provisioning the UL resource allocation associated with an event-triggered reporting (and that may have triggered periodic reporting) may be used to deactivate the periodic reporting or / and the periodic UL resources if the periodic reporting is active. For example, a field which is used to activate or trigger the periodic reporting may be used also to deactivate the active periodic LI measurement reporting or / and the periodic UL resources. For example, when UE receives the field the first time, UE will activate the periodic reporting in response to the field; when UE receives the field the second time, UE will deactivate the periodic reporting in response to the field. In some examples, the downlink control message may contain a field indicating the information of the event or event-triggered reporting for which the periodic LI measurement reporting needs to be deactivated.

[0163] If base station 20 instructs UE 10 to deactivate the periodic LI measurement reporting, UE 10 may deactivate only the periodic LI measurement reporting, but the periodic UL resources may be still active for example for transmissions of other data of control information, or for transmissions of LI measurement reports triggered by other events that base station 20 does not instruct UE 10 to deactivate. If base station 20 instructs UE 10 to deactivate the periodic UL resources, UE 10 may deactivate the periodic UL resources and the periodic LI measurement reporting on the periodic UL resources.

[0164] In an example, UE 10 may deactivate the periodic LI measurement reporting and optionally the periodic UL resources when UE 10 receives from base station 20 an indication to deactivate at least one TCI state of a candidate cell or a reference signal (RS) / beam of the candidate cell associated with the event-triggered LI measurement reporting, or an indication to activate at least one TCI state of an RS / beam or a candidate cell different from the RS / beam or the candidate cell associated with the event-triggered LI measurement reporting, or a PDCCH order triggering an RACH preamble transmission towards a candidate cell different from the candidate cell associated with the event-triggered LI measurement reporting. In the LTM procedure, base station 20 can activate at least one TCI state of a target candidate cell or a reference signal (RS) or beam of the candidate cell in advance before the target candidate cell becomes the serving cell, which allows UE 10 to be DL synchronized with the target candidate cell. UE 10 may also be UL synchronized with the target candidate cell through an early TA acquisition procedure which may be triggered by PDCCH order or realized through UE-based TA measurement. As UE 10 is DL and UL synchronized with the target candidate cell, a faster cell switch can be performed when the cell switch is triggered to the target candidate cell. If UE 10 receives from base station 20 the indication to deactivate at least one TCI state of the RS / beamor candidate cell associated with the event-triggered LI measurement reporting, UE 10 may interpret it as an implication that the candidate cell is not selected as the target candidate cell and there is small possibility of cell switch to the candidate cell. Therefore, UE 10 may decide to deactivate the periodic LI measurement reporting associated with the candidate cell and optionally the periodic UL resources for the event-triggered LI measurement reporting. Each cell may be configured with more than one RSs or beams. If base station 20 deactivates the TCI state of an RS or beam of the candidate cell different from the RS or beam of the candidate cell for which the event-triggered LI measurement reporting is triggered, UE 10 may also deactivate the periodic LI measurement reporting associated with the candidate cell and optionally the periodic UL resources for the event-triggered LI measurement reporting.

[0165] In some LTM use cases, base station 20 may select only one of the candidate cells configured for UE 10 as the target candidate cell. If UE 10 receives from base station 20 an indication to activate at least one TCI state of an RS, a candidate beam or a candidate cell different from the RS, the candidate beam or the candidate cell associated with the event- triggered LI measurement reporting, or a PDCCH order triggering an RACH preamble transmission towards a candidate cell different from the candidate cell associated with the event- triggered LI measurement reporting, UE 10 may interpret the TCI state activation indication or the PDCCH order as an implication that a new candidate cell is selected as the target candidate cell, and the candidate cell associated with the event-triggered LI measurement reporting is not selected as the target candidate cell any longer. Therefore, UE 10 may decide to deactivate the periodic LI measurement reporting associated with the candidate cell and optionally the periodic UL resources for the event-triggered LI measurement reporting.

[0166] In an example, UE 10 may decide to deactivate the periodic LI measurement reporting and optionally the periodic UL resources for the event-triggered LI measurement reporting when UE 10 receives a cell switch command from base station 20. UE 10 will switch to a new serving cell indicated in the cell switch command, and the base station to which the new serving cell belongs may configure new event-triggered reporting configurations for UE 10.

[0167] In some examples, UE 10 may deactivate the periodic LI measurement reporting and optionally the periodic UL resources for the event-triggered LI measurement reporting based on one or more conditions determined at UE 10.

[0168] In an example, when UE 10 decides to deactivate at least one TCI state of the RS, the candidate beam or the candidate cell associated with the event-triggered LI measurement reporting, UE 10 may deactivate the periodic LI measurement reporting and optionally the periodic UL resources for the event-triggered LI measurement reporting. For example, UE 10may decide to deactivate at least one TCI state of the RS, the candidate beam or the candidate cell based on the LI measurements of the RS, the candidate beam or the candidate cell. If the LI measurements show that quality of RS, the candidate beam or the candidate cell becomes worse than an absolute threshold or an amount of offset worse than another candidate cell or an RS or beam of the another candidate cell or the current serving cell, UE 10 may determine that the candidate cell is not selected as the target candidate cell any longer and the TCI state of the RS, the candidate beam or the candidate cell is deactivated. Therefore, UE 10 may decide to deactivate the periodic LI measurement reporting associated with the candidate cell and optionally the periodic UL resources for the event-triggered LI measurement reporting.

[0169] In an example, when UE 10 decides to trigger or initiate UL synchronization with an RS, a candidate beam or a candidate cell different from the RS, the candidate beam or the candidate cell associated with the event-triggered LI measurement reporting, UE 10 may deactivate the periodic LI measurement reporting and optionally the periodic UL resources for the event-triggered LI measurement reporting. As discussed above, in a case where only one candidate cell is selected as the target candidate cell, UE’s synchronization with a new candidate cell implies that the new candidate cell is selected as the target candidate cell, and the candidate cell associated with the event-triggered LI measurement reporting is not selected as the target candidate cell any longer. Therefore, UE 10 may decide to deactivate the periodic LI measurement reporting associated with the candidate cell and optionally the periodic UL resources for the event-triggered LI measurement reporting.

[0170] In an example, when UE 10 declares beam failure with the candidate beam or the candidate cell associated with the event-triggered LI measurement reporting, UE 10 may decide to deactivate the periodic LI measurement reporting and optionally the periodic UL resources for the event-triggered LI measurement reporting.

[0171] In some examples, UE 10 may deactivate the periodic LI measurement reporting and optionally the periodic UL resources for the event-triggered LI measurement reporting based on the LI measurement results obtained at UE 10. For example, if the LI measurement results show that the candidate cell associated with the periodic LI measurement reporting becomes not suitable for being selected as the target candidate cell, UE 10 may decide to deactivate the periodic LI measurement reporting associated with the candidate cell and optionally the periodic UL resources for the event-triggered LI measurement reporting.

[0172] In an example, UE 10 may determine that the candidate cell is not suitable for being selected as the target candidate cell if the LI measurement results show at least one of the following conditions:- quality of the RS, the candidate beam or the candidate cell becomes below a threshold,- difference between quality of the RS, the candidate beam or the candidate cell and quality of a serving cell RS, a serving cell indicated beam or the serving cell becomes below a threshold, or- quality of the serving cell or the serving cell indicated beam becomes above a threshold.

[0173] The above conditions / measurement results are described by way of example, and other conditions / measurement results may also be used to determine whether the candidate cell is suitable for being selected as the target candidate cell or not. If the candidate cell is not suitable for being selected as the target candidate cell, UE 10 may decide to deactivate the periodic LI measurement reporting associated with the candidate cell and optionally the periodic UL resources for the event-triggered LI measurement reporting.

[0174] As discussed above, base station 20 may determine, e.g., for the configuration for the periodic event-triggered LI measurement reporting, the maximum number of periodic LI measurement reports allowed to be transmitted once the corresponding event is triggered. In an example, UE 10 may decide to deactivate the periodic LI measurement reporting and optionally the periodic UL resources for the event-triggered LI measurement reporting when the periodic LI measurement reports have been transmitted for the maximum number of times, or when the maximum number of occasions of the periodic UL resources for the periodic event-triggered LI measurement reporting have elapsed regardless of whether the number of reports have been actually transmitted.

[0175] In an example, base station 20 may schedule non-event based LI measurement reporting, e.g., a periodic or semi-persistent CSI reporting, for the candidate cell or the RS / beam of the candidate cell. If UE 10 receives from base station 20 an indication to activate the non-event based LI measurement reporting (e.g., the periodic or semi-persistent CSI reporting) for the candidate cell or the RS / beam of the candidate cell associated with the event-triggered LI measurement reporting, UE 10 may decide to deactivate the periodic LI measurement reporting associated with the candidate cell and optionally the periodic UL resources for the event- triggered LI measurement reporting.

[0176] In an example, when UE 10 decides to pre-process the candidate cell configuration of a candidate cell different from the candidate cell associated with the event-triggered LI measurement reporting, UE 10 may deactivate the periodic LI measurement reporting and optionally the periodic UL resources for the event-triggered LI measurement reporting. The preprocessing refers ASN.l decoding or / and validity check of the candidate cell configuration before cell switch.

[0177] Some examples of conditions have been described above for triggering deactivation of the periodic LI measurement reporting and optionally the periodic UL resources for the event- triggered LI measurement reporting. The example embodiments are not limited in any way to the example conditions described above, and other conditions may also be used as a trigger for deactivation of the periodic LI measurement reporting and optionally the periodic UL resources for the event-triggered LI measurement reporting.

[0178] With reference to Fig. 11, method 800 may comprise, 816, transmitting a notification of the deactivation to base station 20. The notification may indicate that UE 10 has deactivated the periodic LI measurement reporting, or both the periodic LI measurement reporting and the periodic UL resources for the periodic LI measurement reporting. The notification may be sent in an uplink control information or in a MAC-CE or in an RRC message. In some examples, base station 20 can know the deactivation of the periodic LI measurement reporting and the periodic UL resources, and block 816 may be omitted. For example, if UE 10 carries out the deactivation based on an indication or message received from base station 20 as discussed above, base station 20 would also know the deactivation.

[0179] Fig 12 is a schematic block diagram illustrating an example of apparatus 900. Apparatus 900 may be implemented to comprise or to form at least a part of a terminal device such as UE 10 discussed above. The blocks of apparatus 900 may be implemented with software, hardware, firmware or any combination thereof to perform at least a part of operations related to UE 10.

[0180] Referring to Fig. 12, apparatus 900 may comprise means 910 for transmitting periodic event-triggered LI measurement reports to a network device e.g. base station 20 discussed above after the associated event is met. Means 910 may transmit the periodic event-triggered LI measurement reports on periodic UL resources associated with an event-triggered LI measurement reporting. For example, means 910 may transmit the periodic LI measurement reports based on a period UL grant configuration allocating the periodic UL resources for the event-triggered LI measurement reporting.

[0181] Apparatus 900 may comprise means 912 for deactivating the periodic LI measurement reporting for an event-triggered LI measurement reporting if a predefined condition is fulfilled. In an example, apparatus 900 may further comprise means 914 for deactivating the periodic UL resources for the event-triggered LI measurement reporting in response to the predefined condition being fulfilled. Apparatus 900 may deactivate the periodic LI measurement reporting only, or deactivate both the periodic LI measurement reporting and the periodic UL resources for the event-triggered LI measurement reporting.

[0182] In some examples, means 912 may deactivate the periodic LI measurement reporting and, optionally, means 914 may deactivate the periodic UL resources for the event-triggered LI measurement reporting, based on an indication received from base station 20. For example, base station 20 may send to apparatus 900 an indication indicating deactivation of a configuration for the event-triggered LI measurement reporting, and / or an indication indicating deactivation of a periodic UL grant configuration allocating the periodic UL resources for the event-triggered LI measurement reporting. If base station 20 indicates to deactivate the periodic LI measurement reporting, means 912 may deactivate the periodic LI measurement reporting, but the periodic UL resources may be maintained active for example for transmissions of other data of control information, or for transmissions of LI measurement reports triggered by other events that are not requested to be deactivated. If base station 20 indicates to deactivate the periodic UL resources, means 914 may deactivate the periodic UL resources, and means 912 may deactivate the periodic LI measurement reporting on the periodic UL resources.

[0183] In an example, the indication to deactivate periodic LI measurement reporting of an event-triggered reporting may be received in a downlink control message. The downlink control message may be a DCI or MAC-CE message. In some examples, a field may be used to inform about the deactivation of the periodic LI measurement reporting. When the value of the field is set to a first value, e.g., “0”, it may indicate that the periodic LI measurement reporting or / and periodic UL resources associated with the periodic LI measurement reporting are deactivated, and when the field is set to a second value, e.g., “1” it may indicate no change in the reporting configuration. In an example, the field provisioning the UL resource allocation associated with an event-triggered reporting (and that may have triggered periodic reporting) may be used to deactivate the periodic reporting or / and the periodic UL resources if the periodic reporting is active. For example, a field which is used to activate or trigger the periodic reporting may be used also to deactivate the active periodic LI measurement reporting or / and the periodic UL resources. For example, when UE receives the field the first time, UE will activate the periodic reporting in response to the field; when UE receives the field the second time, UE will deactivate the periodic reporting in response to the field. In some examples, the downlink control message may contain a field indicating the information of the event or event-triggered reporting for which the periodic LI measurement reporting needs to be deactivated.

[0184] In an example, means 912 may deactivate the periodic LI measurement reporting and, optionally, the means 914 may deactivate the periodic UL resources for the event-triggered LI measurement reporting when apparatus 900 receives from base station 20 an indication to deactivate at least one TCI state of a candidate cell or a reference signal (RS) / beam of thecandidate cell associated with the event-triggered LI measurement reporting, or an indication to activate at least one TCI state of an RS / beam or a candidate cell different from the RS / beam or the candidate cell associated with the event-triggered LI measurement reporting, or a PDCCH order triggering an RACH preamble transmission towards a candidate cell different from the candidate cell associated with the event-triggered LI measurement reporting. Apparatus 900 may interpret such indications, including the PDCCH order, as an implication that the candidate cell associated with the event-triggered LI measurement reporting is not selected as the target candidate cell any longer and there is small possibility of cell switch to the candidate cell. Therefore, means 912 may deactivate the periodic LI measurement reporting associated with the candidate cell and, optionally, means 914 may deactivate the periodic UL resources for the event- triggered LI measurement reporting.

[0185] In an example, means 912 may deactivate the periodic LI measurement reporting and means 914 may deactivate the periodic UL resources for the event-triggered LI measurement reporting, in response to a cell switch command received from base station 20.

[0186] In some examples, means 912 may deactivate the periodic LI measurement reporting and, optionally, means 914 may deactivate the periodic UL resources for the event-triggered LI measurement reporting, based on one or more conditions determined at apparatus 900. For example, if apparatus 900 decides to deactivate at least one TCI state of the RS, the candidate beam or the candidate cell associated with the event-triggered LI measurement reporting, means 912 may deactivate the periodic LI measurement reporting and, optionally, means 914 may deactivate the periodic UL resources for the event-triggered LI measurement reporting. Apparatus 900 may decide to deactivate at least one TCI state of the RS, the candidate beam or the candidate cell based on the LI measurements of the RS, the candidate beam or the candidate cell. If the LI measurements show that quality of RS, the candidate beam or the candidate cell becomes worse than an absolute threshold or an amount of offset worse than another candidate cell, an RS or beam of the another candidate cell, or the current serving cell, the candidate cell may not be selected as the target candidate cell any longer and the TCI state of the candidate cell or the RS / beam of the candidate cell may be deactivated. Therefore, means 912 may deactivate the periodic LI measurement reporting and, optionally, means 914 may deactivate the periodic UL resources for the event-triggered LI measurement reporting.

[0187] In an example, when apparatus 900 triggers or initiates UL synchronization with an RS, a candidate beam or a candidate cell different from the RS, the candidate beam or the candidate cell associated with the event-triggered LI measurement reporting, means 912 may deactivate the periodic LI measurement reporting and, optionally, means 914 may deactivate the periodicUL resources for the event-triggered LI measurement reporting. As discussed above, in a case where only one candidate cell is selected as the target candidate cell, UE’s synchronization with a new candidate cell implies that the new candidate cell is selected as the target candidate cell, and the candidate cell associated with the event-triggered LI measurement reporting is not selected as the target candidate cell any longer. Therefore, means 912 may deactivate the periodic LI measurement reporting and, optionally, means 914 may deactivate the periodic UL resources for the event-triggered LI measurement reporting.

[0188] In an example, when beam failure is declared with the candidate beam or the candidate cell associated with the event-triggered LI measurement reporting, means 912 may deactivate the periodic LI measurement reporting and, optionally, means 914 may deactivate the periodic UL resources for the event-triggered LI measurement reporting.

[0189] In some examples, means 912 may deactivate the periodic LI measurement reporting and, optionally, means 914 may deactivate the periodic UL resources for the event-triggered LI measurement reporting, based on the LI measurement results of the RS / beam or candidate cell associated with the event-triggered LI measurement reporting. For example, if the LI measurement results show that the candidate cell associated with the event-triggered LI measurement reporting becomes not suitable for being selected as the target candidate cell, means 912 may deactivate the periodic LI measurement reporting associated with the candidate cell and, optionally, means 914 may deactivate the periodic UL resources for the event-triggered LI measurement reporting.

[0190] In an example, a candidate cell is not suitable for being selected as the target candidate cell if the LI measurement results of the candidate cell show at least one of the following conditions:- quality of the candidate cell or the RS / beam of the candidate cell becomes below a threshold,- difference between quality of the candidate cell or the RS / beam of the candidate cell and quality of a serving cell or an RS / beam of the serving cell becomes below a threshold, or- quality of the serving cell or the serving cell indicated beam becomes above a threshold.

[0191] The above conditions / measurement results are described by way of example, and other conditions / measurement results may also be used to determine whether the candidate cell is suitable for being selected as the target candidate cell or not. If the candidate cell is not suitable for being selected as the target candidate cell, means 912 may deactivate the periodic LI measurement reporting associated with the candidate cell and, optionally, means 914 may deactivate the periodic UL resources for the event-triggered LI measurement reporting.

[0192] In an example, when the periodic LI measurement reports have been transmitted for amaximum number of times, or when the maximum number of occasions of the periodic UL resources for the periodic event-triggered LI measurement reporting have elapsed regardless of whether the number of reports have been actually transmitted, means 912 may deactivate the periodic LI measurement reporting and, optionally, means 914 may deactivate the periodic UL resources for the event-triggered LI measurement reporting.

[0193] In an example, base station 20 may schedule non-event based LI measurement reporting, e.g., a periodic or semi-persistent CSI reporting, for a candidate cell or an RS / beam of the candidate cell. In response to an indication received from base station 20 indicating activation of the non-event based LI measurement reporting (e.g., the periodic or semi-persistent CSI reporting) for the candidate cell or the RS / beam of the candidate cell associated with the event- triggered LI measurement reporting, means 912 may deactivate the periodic LI measurement reporting associated with the candidate cell and, optionally, means 914 may deactivate the periodic UL resources for the event-triggered LI measurement reporting.

[0194] In an example, when apparatus 900 decides to pre-process the candidate cell configuration of a candidate cell different from the candidate cell associated with the event- triggered LI measurement reporting, means 912 may deactivate the periodic LI measurement reporting and optionally means 914 may deactivate the periodic UL resources for the event- triggered LI measurement reporting. The pre-processing refers ASN. l decoding or / and validity check of the candidate cell configuration before cell switch.

[0195] Some examples of conditions for triggering deactivation of the periodic LI measurement reporting and optionally the periodic UL resources for the event-triggered LI measurement reporting have been described above. The example embodiments are not limited in any way to the example conditions described above, and other conditions may also be used as a trigger for deactivation of the periodic LI measurement reporting and optionally the periodic UL resources for the event-triggered LI measurement reporting.

[0196] With reference to Fig. 12, apparatus 900 may comprise means 916 for transmitting a notification of the deactivation to base station 20. The notification may indicate that the periodic LI measurement reporting is deactivated, or both the periodic LI measurement reporting and the periodic UL resources for the event-triggered LI measurement reporting are deactivated. In some examples, base station 20 can know the deactivation of the periodic LI measurement reporting and the periodic UL resources, means 916 may be omitted. For example, if the deactivation is carried out in response to an indication or message received from base station 20 as discussed above, the base station 20 would also know the deactivation.

[0197] Fig 13 is a schematic flowchart illustrating an example of method 1000 for deactivatingthe periodic event-triggered LI measurement reporting. Method 1000 may be implemented at a network device, e.g., base station 20 discussed above.

[0198] Referring to Fig. 13, method 1000 may comprise, 1010, receiving periodic event- triggered LI measurement reports from a terminal device e.g. UE 10 discussed above after the associated event is met. The periodic event-triggered LI measurement reports may be received on periodic UL resources associated with periodic event-triggered LI measurement reporting. For example, base station 20 may receive the periodic LI measurement reports based on a period UL grant configuration allocating the periodic UL resources for the periodic reporting.

[0199] In an example, method 1000 may comprise, 1012, receiving a notification from UE 10 indicating that UE 10 has deactivated the periodic LI measurement reporting, or both the periodic LI measurement reporting and the periodic UL resources for the event-triggered LI measurement reporting. In some examples, if UE 10 carries out the deactivation based on an indication or message received from base station 20, base station 20 would also know the deactivation, and block 1012 may be omitted.

[0200] Method 1000 may comprise, 1014, stopping receiving the periodic event-triggered LI measurement reports if a predefined condition is fulfilled and, optionally, 1016, deactivating the periodic uplink resources for the event-triggered LI measurement reporting in response to the predefined condition being fulfilled. For example, if the periodic UL resources are specific for the periodic LI measurement reporting, base station 20 may deactivate the periodic UL resources when it stops receiving the periodic LI measurement reports. If the periodic UL resources are also applicable for transmissions of other data or control information, base station 20 may stop receiving the periodic LI measurement reports but maintain the periodic UL resources active.

[0201] In an example, base station 20 may decide to stop receiving the periodic event-triggered LI measurement reports and, optionally, deactivate the periodic UL resources in response to the notification received from UE 10 at 1012.

[0202] In an example, as discussed above, UE 10 may deactivate the periodic LI measurement reporting and the periodic UL resources in response to an indication received from base station 20. Hence base station 20 may stop receiving the periodic event-triggered LI measurement reports and optionally deactivate the periodic UL resources when it transmits the indication to UE 10. For example, base station 20 may stop receiving the periodic event-triggered LI measurement reports and optionally deactivate the periodic UL resources when base station 20 transmit at least one of the following indications to UE 10:- an indication to deactivate the periodic event-triggered LI measurement reporting, which may be associated with a configuration for event-triggered LI measurement reporting;- an indication to deactivate the periodic UL resources for the periodic event-triggered LI measurement reporting, which may be associated with a periodic UL grant configuration allocating the periodic UL resources;- an indication to deactivate at least one TCI state of a candidate cell or an RS / beam of the candidate cell associated with the event-triggered LI measurement reporting;- an indication to activate at least one TCI state of an RS / beam or candidate cell different from the RS / beam or candidate cell associated with the event-triggered LI measurement reporting;- a PDCCH order triggering an RACH preamble transmission towards a candidate cell different from the candidate cell associated with the event-triggered LI measurement reporting; or- a cell switch command.

[0203] As the above-listed example indications / messages have been discussed in the above description, a redundant description thereof is omitted here for convenience. The example embodiments are not limited in any way to the example indications / messages described above, and other indications / messages may also be used as a trigger for base station 20 to stop receiving the periodic LI measurement reports and optionally deactivate the periodic UL resources for the event-triggered LI measurement reporting.

[0204] In an example, as discussed above, base station 20 may define, for example for the configuration of the event-triggered LI measurement reporting, the maximum number of periodic LI measurement reports allowed to be transmitted once the corresponding event is triggered. Then base station 20 may decide to stop receiving the periodic LI measurement reports and optionally deactivate the periodic UL resources for the periodic LI measurement reporting when the number of periodic LI measurement reports received from UE 10 reaches the maximum limit, or when the maximum number of occasions of the periodic UL resources for the event-triggered LI measurement reporting have elapsed regardless of whether the maximum number of reports have been actually received.

[0205] In an example, base station 20 may schedule non-event based LI measurement reporting, e.g., a periodic or semi-persistent CSI reporting, for a candidate cell or an RS / beam of the candidate cell. If base station 20 schedules the non-event based LI measurement reporting for an RS / beam or candidate cell associated with the event-triggered LI measurement reporting and informs UE 10 to activate the scheduled non-event based LI measurement reporting, base station 20 may decide to stop receiving the periodic LI measurement reports and optionally deactivate the periodic UL resources for the event-triggered LI measurement reporting.

[0206] Fig 14 is a schematic block diagram illustrating an example of apparatus 1100.Apparatus 1100 may be implemented to comprise or to form at least a part of a network device such as base station 20 discussed above. The blocks of apparatus 1100 may be implemented with software, hardware, firmware or any combination thereof to perform at least a part of operations related to base station 20.

[0207] Referring to Fig. 14, apparatus 1100 may comprise means 1110 for receiving periodic event-triggered LI measurement reports from a terminal device e.g., UE 10 discussed above. In an example, the periodic event-triggered LI measurement reports may be received on periodic UL resources for an event-triggered LI measurement reporting after the associated event is met.

[0208] In an example, apparatus 1100 may comprise means 1112 for receiving a notification from UE 10 indicating that UE 10 has deactivated the periodic LI measurement reporting, or both the periodic LI measurement reporting and the periodic UL resources for the event- triggered LI measurement reporting. In some examples, if UE 10 carries out the deactivation based on an indication or message received from apparatus 1100, apparatus 1100 would also know the deactivation, and means 1112 may be omitted.

[0209] Apparatus 1100 may comprise means 1114 for stopping receiving the periodic event- triggered LI measurement reports when a predefined condition is fulfilled and, optionally, means 1116 for deactivating the periodic uplink resources for the event-triggered LI measurement reporting in response to the predefined condition being fulfilled. For example, if the periodic UL resources are specific for the periodic LI measurement reporting, means 1116 may deactivate the periodic UL resources when means 1114 stops receiving the periodic LI measurement reports. If the periodic UL resources are also applicable for transmissions of other data or control information, when means 1114 stops receiving the periodic LI measurement reports, means 1116 may maintain the periodic UL resources active.

[0210] In an example, means 1114 may stop receiving the periodic event-triggered LI measurement reports and, optionally, means 1116 may deactivate the periodic UL resources in response to the notification received at means 1112 from UE 10.

[0211] In an example, means 1114 may stop receiving the periodic event-triggered LI measurement reports and, optionally, means 1116 may deactivate the periodic UL resources for the event-triggered LI measurement reporting, when at least one of the following indications / messages is transmitted to UE 10:- an indication to deactivate the periodic event-triggered LI measurement reporting, which may be associated with a configuration for event-triggered LI measurement reporting;- an indication to deactivate the periodic UL resources for the event-triggered LI measurement reporting, which may be associated with a periodic UL grant configurationallocating the periodic UL resources;- an indication to deactivate at least one TCI state of a candidate cell or an RS / beam of the candidate cell associated with the event-triggered LI measurement reporting;- an indication to activate at least one TCI state of an RS / beam or candidate cell different from the RS / beam or candidate cell associated with the event-triggered LI measurement reporting;- a PDCCH order triggering an RACH preamble transmission towards a candidate cell different from the candidate cell associated with the event-triggered LI measurement reporting; or- a cell switch command.

[0212] In an example, means 1114 may stop receiving the periodic event-triggered LI measurement reports and, optionally, means 1116 may deactivate the periodic UL resources for the event-triggered LI measurement reporting, when the number of periodic LI measurement reports received from UE 10 reaches the maximum limit set in the periodic LI measurement reporting configuration, or when the maximum number of occasions of the periodic UL resources for the periodic event-triggered LI measurement reporting have elapsed regardless of whether the maximum number of reports have been actually received.

[0213] In an example, if a non-event based LI measurement reporting, e.g., a periodic or semi- persistent CSI reporting, is scheduled and activated for a candidate cell or an RS / beam of the candidate cell associated with the periodic LI measurement reporting, means 1114 may stop receiving the periodic event-triggered LI measurement reports associated with the candidate cell or the RS / beam of the candidate cell and, optionally, means 1116 may deactivate the periodic UL resources for the event-triggered LI measurement reporting.

[0214] Fig 15 illustrates an example of terminal device 1200. Referring to Fig. 15, terminal device 1200 may comprise one or more processors 1210, one or more memories 1220 and one or more transceivers 1230 interconnected through one or more buses 1240. One or more buses 1240 may be address, data, or control buses, and may include any interconnection mechanism such as series of lines on a motherboard or integrated circuit, fiber, optics or other optical communication equipment, and the like. Each of one or more transceivers 1230 may comprise a receiver and a transmitter, which are connected to one or more antennas 1250. Terminal device 1200 may wirelessly communicate with a network device e.g. a base station through one or more antennas 1250. One or more memories 1220 may include instructions 1222 which, when executed by one or more processors 1210, may cause terminal device 1200 to perform operations relating to UE 10 described above.

[0215] Fig 16 illustrates an example of network device 1300. Referring to Fig. 16, networkdevice 1300 may comprise one or more processors 1310, one or more memories 1320, one or more transceivers 1330 and one or more network interfaces 1360 interconnected through one or more buses 1340. One or more buses 1340 may be address, data, or control buses, and may include any interconnection mechanism such as a series of lines on a motherboard or integrated circuit, fiber, optics or other optical communication equipment, and the like. Each of one or more transceivers 1330 may comprise a receiver and a transmitter, which are connected to one or more antennas 1350. Network device 1300 may operate as a master node, a secondary node, a candidate master node or a candidate secondary node for terminal device 1200 in a dual connectivity mode, or as a single serving base station for terminal device 1200 in a single connectivity mode. Network device 1300 may wirelessly communicate with terminal device 1200 through one or more antennas 1350. One or more network interfaces 1360 may provide wired or wireless communication links through which network device 1300 may communicate with other network devices, entities, elements or functions. For example, network device 1300 may communicate with a core network (not shown) via backhaul connections. One or more memories 1320 may include instructions 1322 which, when executed by one or more processors 1310, may cause network device 1300 to perform operations relating to base station 20 described above.

[0216] One or more processors 1210, 1310 discussed above may be of any appropriate type that is suitable for the local technical network, and may include one or more of general purpose processors, special purpose processor, microprocessors, a digital signal processor (DSP), one or more processors in a processor based multi-core processor architecture, as well as dedicated processors such as those developed based on Field Programmable Gate Array (FPGA) and Application Specific Integrated Circuit (ASIC). One or more processors 1210, 1310 may be configured to control other elements of the terminal / network devices and operate in cooperation with them to implement the procedures discussed above.

[0217] One or more memories 1220, 1320 may include at least one storage medium in various forms, such as a transitory memory and / or a non-transitory memory. The transitory memory may include, but not limited to, for example, a random access memory (RAM) or a cache. The non- transitory memory may include, but not limited to, for example, a read only memory (ROM), a hard disk, a flash memory, 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). Further, one or more memories 1220, 1320 may include but not limited to an electric, a magnetic, an optical, an electromagnetic, an infrared, or a semiconductor system, apparatus, or device or any combination of the above.

[0218] It would be understood that blocks in the drawings may be implemented in various manners, including software, hardware, firmware, or any combination thereof. In some embodiments, one or more blocks may be implemented using software and / or firmware, for example, machine-executable instructions stored in the storage medium. In addition to or instead of machine-executable instructions, parts or all of the blocks in the drawings may be implemented, at least in part, by one or more hardware logic components. For example, and without limitation, illustrative types of hardware logic components that can be used include Field-Programmable Gate Arrays (FPGAs), Application-Specific Integrated Circuits (ASICs), Application-Specific Standard Products (ASSPs), System-on-Chip systems (SOCs), Complex Programmable Logic Devices (CPLDs), etc.

[0219] Some example embodiments further provide program instruction or instructions which, when executed by one or more processors, may cause a device or apparatus to perform the procedures described above. The program instruction for carrying out procedures of the example embodiments may be written in any combination of one or more programming languages. The program instruction may be provided to one or more processors or controllers of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program instruction, when executed by the processor or controller, cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program instruction 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.

[0220] Some example embodiments further provide a computer program product or a computer readable medium having the program instruction or instructions stored therein. The computer readable medium may be any tangible medium that may contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. The machine readable medium may be a machine readable signal medium or a machine readable storage medium. A machine readable medium may include but is 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 machine 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.

[0221] 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.

[0222] Further, while 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, while 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. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable sub-combination.

[0223] Throughout the present disclosure, reference to “one embodiment,” “an embodiment,” “some embodiments,” “other embodiments,” etc. indicates that one or more particular features, structures, steps, concepts, and / or characteristics in accordance with principles of the present disclosure may be included in connection with the embodiment. However, such references do not necessarily mean that all embodiments include the particular features, structures, steps, concepts, and / or characteristics, or that an embodiment includes all features, structures, steps, concepts, and / or characteristics. Some embodiments may include one or more such features, structures, steps, concepts, and / or characteristics, in various combinations thereof. It should be understood that one or more of the features, structures, steps, concepts, and / or characteristics described with reference to one embodiment can be combined with one or more of the features, structures, steps, concepts, and / or characteristics of any of the other embodiments provided herein. That is, any of the features, structures, steps, concepts, and / or characteristics described herein can be mixed and matched to create hybrid embodiments, and such hybrid embodiments are within the scope of the present disclosure. Moreover, references to “one embodiment,” “an embodiment,” “some embodiments,” “other embodiments,” etc. in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments. It should further be understood that various features, structures, steps, concepts, and / or characteristics of disclosed embodiments are independent of and separate from one another, and may be used orpresent individually or in various combinations with one another to create alternative embodiments which are considered part of the present disclosure. Therefore, the present disclosure is not limited to only the embodiments specifically described herein, as it would be too cumbersome to describe all of the numerous possible combinations and subcombinations of features, structures, steps, concepts, and / or characteristics, and the examples of embodiments disclosed herein are not intended as limiting the broader aspects of the present disclosure.

[0224] Although the subject matter has been described in a language that is specific to structural features and / or method actions, it is to be understood the subject matter defined in the appended claims is not limited to the specific features or actions described above. On the contrary, the above-described specific features and actions are disclosed as an example of implementing the claims.

Claims

CLAIMS:

1. A terminal device, comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the terminal device at least to perform: periodically transmitting, to a network device, event-triggered Layer 1 measurement reports on periodic uplink resources associated with an event-triggered Layer 1 measurement reporting after the associated event is met; and deactivating the periodic transmission of the event-triggered Layer 1 measurement reports in response to a predefined condition being fulfilled.

2. The terminal device of claim 1, wherein the instructions, when executed by the at least one processor, further cause the terminal device at least to perform: deactivating the periodic uplink resources for the periodic transmission of the event- triggered Layer 1 measurement reports in response to the predefined condition being fulfilled.

3. The terminal device of claim 1 or 2, wherein the predefined condition comprises reception of an indication from the network device.

4. The terminal device of claim 3, wherein the indication received from the network device comprises at least one of the following: a first indication to deactivate the periodic transmission of the event-triggered Layer 1 measurement reports, a second indication to deactivate the periodic uplink resources on which the event-triggered Layer 1 measurement report are periodically transmitted, a third indication to deactivate at least one transmission configuration indicator state of a reference signal, a candidate beam or a candidate cell associated with the event-triggered Layer 1 measurement reporting,a fourth indication to activate at least one transmission configuration indicator state of a reference signal, a candidate beam or a candidate cell different from the reference signal, the candidate beam or the candidate cell associated with the event-triggered Layer 1 measurement reporting, a physical downlink control channel order triggering a random access preamble transmission towards a candidate cell different from the candidate cell associated with the event- triggered Layer 1 measurement reporting, or a cell switch command.

5. The terminal device of claim 4, wherein the first indication is associated with an event- triggered Layer 1 measurement reporting configuration based on which the event-triggered Layer 1 measurement reports are triggered, the second indication is associated with a periodic uplink grant configuration configuring the periodic uplink resources.

6. The terminal device of claim 1 or 2, wherein the predefined condition comprises at least one of the following: the terminal device determines to deactivate at least one transmission configuration indicator state of a reference signal, a candidate beam or a candidate cell associated with the event-triggered Layer 1 measurement reporting, uplink synchronization is triggered or initiated for a reference signal, a candidate beam or a candidate cell different from the reference signal, the candidate beam or the candidate cell associated with the event-triggered Layer 1 measurement reporting, beam failure is declared for the candidate beam or the candidate cell associated with the event-triggered Layer 1 measurement reporting, or a candidate cell configuration is pre-processed for a candidate cell different from the candidate cell associated with the event-triggered Layer 1 measurement reporting.

7. The terminal device of claim 1 or 2, wherein the predefined condition is related to Layer 1 measurement result obtained at the terminal device.

8. The terminal device of claim 7, wherein the predefined condition comprises at least one of the following: quality of a candidate reference signal, a candidate beam or a candidate cell comprised in the event-triggered Layer 1 measurement report becomes below a first threshold, difference in quality between the candidate reference signal, the candidate beam or the candidate cell and a serving cell reference signal, a serving cell indicated beam or a serving cell becomes below a second threshold, or the serving cell or serving cell indicated beam quality becomes above a third threshold.

9. The terminal device of claim 1 or 2, wherein the predefined condition comprises at least one of the following: non-event based Layer 1 measurement reporting is scheduled for a reference signal, a candidate beam or a candidate cell associated with the event-triggered Layer 1 measurement reporting, the event-triggered Layer 1 measurement report has been periodically transmitted for a predetermined number of times, or a predetermined number of occasions of the periodic uplink resources have elapsed for the periodic transmission of the event-triggered Layer 1 measurement reports.

10. The terminal device of any of claims 1 to 9, wherein the instructions, when executed by the at least one processor, further cause the terminal device at least to perform: notifying the network device of deactivation of the periodic transmission of the event- triggered Layer 1 measurement reports or deactivation of the periodic uplink resources.I L A network device, comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the network device at least to perform:periodically receiving, from a terminal device, event-triggered Layer 1 measurement reports on periodic uplink resources associated with an event-triggered Layer 1 measurement reporting after the associated event is met; and stopping receiving the event-triggered Layer 1 measurement reports in response to a predefined condition being fulfilled.

12. The network device of claim 11, wherein the instructions, when executed by the at least one processor, further cause the network device at least to perform: deactivating the periodic uplink resources for periodic transmission of the event-triggered Layer 1 measurement reports in response to the predefined condition being fulfilled.

13. The network device of claim 11 or 12, wherein the predefined condition comprises an indication being transmitted to the terminal device.

14. The network device of claim 13, wherein the indication transmitted to the terminal device comprises at least one of the following: a first indication to deactivate the periodic transmission of the event-triggered Layer 1 measurement reports, a second indication to deactivate the periodic uplink resources on which the event-triggered Layer 1 measurement reports are periodically transmitted, a third indication to deactivate at least one transmission configuration indicator state of a reference signal, a candidate beam or a candidate cell associated with the event-triggered Layer 1 measurement reporting, a fourth indication to activate at least one transmission configuration indicator state of a reference signal, a candidate beam or a candidate cell different from the reference signal, the candidate beam or the candidate cell associated with the event-triggered Layer 1 measurement reporting, a physical downlink control channel order triggering a random access preamble transmission towards a candidate cell different from the candidate cell associated with the event- triggered Layer 1 measurement reporting, ora cell switch command.

15. The network device of claim 14, wherein the first indication is associated with an event- triggered Layer 1 measurement reporting configuration based on which the event-triggered Layer 1 measurement reports are triggered, the second indication is associated with a periodic uplink grant configuration configuring the periodic uplink resources.

16. The network device of claim 11 or 12, wherein the predefined condition comprises at least one of the following: the network device schedules non-event based Layer 1 measurement reporting of the terminal device for a reference signal, a candidate beam or a candidate cell associated with the event-triggered Layer 1 measurement reporting, the network device receives, from the terminal device, a notification of deactivation of the periodic transmission of the event-triggered Layer 1 measurement reports or deactivation of the periodic uplink resources, the event-triggered Layer 1 measurement reports have been periodically received for a predetermined number of times, or a predetermined number of occasions of the periodic uplink resources have elapsed for the periodic transmission of the event-triggered Layer 1 measurement reports.

17. A method comprising: periodically transmitting, to a network device, event-triggered Layer 1 measurement reports on periodic uplink resources associated with an event-triggered Layer 1 measurement reporting after the associated event is met; and deactivating the periodic transmission of the event-triggered Layer 1 measurement reports in response to a predefined condition being fulfilled.

18. The method of claim 17, further comprising:deactivating the periodic uplink resources for the periodic transmission of the event- triggered Layer 1 measurement reports in response to the predefined condition being fulfilled.

19. The method of claim 17 or 18, wherein the predefined condition comprises reception of an indication from the network device.

20. The method of claim 19, wherein the indication received from the network device comprises at least one of the following: a first indication to deactivate the periodic transmission of the event-triggered Layer 1 measurement reports, a second indication to deactivate the periodic uplink resources on which the event-triggered Layer 1 measurement report are periodically transmitted, a third indication to deactivate at least one transmission configuration indicator state of a reference signal, a candidate beam or a candidate cell associated with the event-triggered Layer 1 measurement reporting, a fourth indication to activate at least one transmission configuration indicator state of a reference signal, a candidate beam or a candidate cell different from the reference signal, the candidate beam or the candidate cell associated with the event-triggered Layer 1 measurement reporting, a physical downlink control channel order triggering a random access preamble transmission towards a candidate cell different from the candidate cell associated with the event- triggered Layer 1 measurement reporting, or a cell switch command.

21. The method of claim 20, wherein the first indication is associated with an event- triggered Layer 1 measurement reporting configuration based on which the event-triggered Layer 1 measurement reports are triggered, the second indication is associated with a periodic uplink grant configuration configuring the periodic uplink resources.

22. The method of claim 17 or 18, wherein the predefined condition comprises at least one of the following: a terminal device determines to deactivate at least one transmission configuration indicator state of a reference signal, a candidate beam or a candidate cell associated with the event- triggered Layer 1 measurement reporting, uplink synchronization is triggered or initiated for a reference signal, a candidate beam or a candidate cell different from the reference signal, the candidate beam or the candidate cell associated with the event-triggered Layer 1 measurement reporting, beam failure is declared for the candidate beam or the candidate cell associated with the event-triggered Layer 1 measurement reporting, or a candidate cell configuration is pre-processed for a candidate cell different from the candidate cell associated with the event-triggered Layer 1 measurement reporting.

23. The method of claim 17 or 18, wherein the predefined condition is related to Layer 1 measurement result obtained at a terminal device.

24. The method of claim 23, wherein the predefined condition comprises at least one of the following: quality of a candidate reference signal, a candidate beam or a candidate cell comprised in the event-triggered Layer 1 measurement report becomes below a first threshold, difference in quality between the candidate reference signal, the candidate beam or the candidate cell and a serving cell reference signal, a serving cell indicated beam or a serving cell becomes below a second threshold, or the serving cell or serving cell indicated beam quality becomes above a third threshold.

25. The method of claim 17 or 18, wherein the predefined condition comprises at least one of the following: non-event based Layer 1 measurement reporting is scheduled for a reference signal, a candidate beam or a candidate cell associated with the event-triggered Layer 1 measurement reporting,the event-triggered Layer 1 measurement report has been periodically transmitted for a predetermined number of times, or a predetermined number of occasions of the periodic uplink resources have elapsed for the periodic transmission of the event-triggered Layer 1 measurement reports.

26. The method of any of claims 17 to 25, further comprising: notifying the network device of deactivation of the periodic transmission of the event- triggered Layer 1 measurement reports or deactivation of the periodic uplink resources.

27. A method comprising: periodically receiving, from a terminal device, event-triggered Layer 1 measurement reports on periodic uplink resources associated with an event-triggered Layer 1 measurement reporting after the associated event is met; and stopping receiving the event-triggered Layer 1 measurement reports in response to a predefined condition being fulfilled.

28. The method of claim 27, further comprising: deactivating the periodic uplink resources for periodic transmission of the event-triggered Layer 1 measurement reports in response to the predefined condition being fulfilled.

29. The method of claim 27 or 28, wherein the predefined condition comprises an indication being transmitted to a terminal device.

30. The method of claim 29, wherein the indication transmitted to the terminal device comprises at least one of the following: a first indication to deactivate the periodic transmission of the event-triggered Layer 1 measurement reports, a second indication to deactivate the periodic uplink resources on which the event-triggered Layer 1 measurement reports are periodically transmitted,a third indication to deactivate at least one transmission configuration indicator state of a reference signal, a candidate beam or a candidate cell associated with the event-triggered Layer 1 measurement reporting, a fourth indication to activate at least one transmission configuration indicator state of a reference signal, a candidate beam or a candidate cell different from the reference signal, the candidate beam or the candidate cell associated with the event-triggered Layer 1 measurement reporting, a physical downlink control channel order triggering a random access preamble transmission towards a candidate cell different from the candidate cell associated with the event- triggered Layer 1 measurement reporting, or a cell switch command.

31. The method of claim 30, wherein the first indication is associated with an event- triggered Layer 1 measurement reporting configuration based on which the event-triggered Layer 1 measurement reports are triggered, the second indication is associated with a periodic uplink grant configuration configuring the periodic uplink resources.

32. The method of claim 27 or 28, wherein the predefined condition comprises at least one of the following: the network device schedules non-event based Layer 1 measurement reporting of a terminal device for a reference signal, a candidate beam or a candidate cell associated with the event- triggered Layer 1 measurement reporting, the network device receives, from the terminal device, a notification of deactivation of the periodic transmission of the event-triggered Layer 1 measurement reports or deactivation of the periodic uplink resources, the event-triggered Layer 1 measurement reports have been periodically received for a predetermined number of times, or a predetermined number of occasions of the periodic uplink resources have elapsed for the periodic transmission of the event-triggered Layer 1 measurement reports.

33. An apparatus, comprising means for performing the method of any of claims 17 to 32.

Images