Channel state information reference resource for measurement reporting

Abstract

Example embodiments of the present disclosure are directed to channel state information (CSI) reference resource for measurement reporting. A method comprises receiving, from a second apparatus, a message at least comprising configuration information associated with a time to trigger (TTT); determining, based on the configuration information, a TTT duration prior to a slot associated with an event-triggered measurement reporting, wherein the TTT duration is associated with a reference signal or a beam to be measured for an event-triggered measurement reporting; determining a CSI reference resource for the event-triggered measurement reporting based at least on the TTT duration.

Description

CHANNEL STATE INFORMATION REFERENCE RESOURCE FOR MEASUREMENT REPORTINGFIELD

[0001] Various example embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to methods, devices, apparatuses and computer readable storage medium for channel state information (CSI) reference resource for measurement reporting.BACKGROUND

[0002] In some discussed schemes, the event-triggered reporting is being considered for layer 1 (LI) measurement reporting for both beam management (BM) (for multiple-input multiple-output (MIMO) purposes) and cell switch procedure such as layer 1 / layer 2-triggered mobility (LTM), where the user equipment (UE) will be configured with events to determine when to send a report containing one or more measurements.SUMMARY

[0003] In a first aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to: receive, from a second apparatus, a message at least comprising configuration information associated with a time to trigger (TTT); determine, based on the configuration information, a TTT duration prior to a slot associated with an event-triggered measurement reporting, wherein the TTT duration is associated with a reference signal or a beam to be measured for an event-triggered measurement reporting; determine a channel State Information (CSI) reference resource for the event-triggered measurement reporting based at least on the TTT duration.

[0004] In a second aspect of the present disclosure, there is provided a method. The method comprises: receiving, by a first apparatus from a second apparatus, a message at least comprising configuration information associated with a TTT; determining, based onthe configuration information, a TTT duration prior to a slot associated with an event-triggered measurement reporting, wherein the TTT duration is associated with a reference signal or a beam to be measured for an event-triggered measurement reporting; determining a CSI reference resource for the event-triggered measurement reporting based at least on the TTT duration.

[0005] In a third aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for receiving, from a second apparatus, a message at least comprising configuration information associated with a TTT; means for determining, based on the configuration information, a TTT duration prior to a slot associated with an event-triggered measurement reporting, wherein the TTT duration is associated with a reference signal or a beam to be measured for an event-triggered measurement reporting; means for determining a CSI reference resource for the event-triggered measurement reporting based at least on the TTT duration.

[0006] In a fourth aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the second aspect.

[0007] It is to be understood that the Summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Some example embodiments will now be described with reference to the accompanying drawings, where:

[0009] FIG. 1 illustrates an example communication environment in which example embodiments of the present disclosure can be implemented;

[0010] FIG. 2 illustrates a signaling chart for the LTM procedure;

[0011] FIG. 3 illustrates an example of a CSI reference resource for periodic reporting;

[0012] FIG. 4 illustrates a signaling chart of communication according to some example embodiments of the present disclosure;

[0013] FIG. 5 illustrates an example diagram related to the timeline of determining theCSI reference resource at the end of the TTT duration in accordance with some example embodiments of the present disclosure;

[0014] FIG. 6 illustrates an example diagram related to the timeline of determining the CSI reference resource with a gap from the end of the TTT duration in accordance with some example embodiments of the present disclosure;

[0015] FIG. 7 illustrates a signaling chart of communication according to some example embodiments of the present disclosure;

[0016] FIG. 8 illustrates a flowchart of a method implemented at a first apparatus in accordance with some example embodiments of the present disclosure;

[0017] FIG. 9 illustrates a flowchart of a method implemented at a first apparatus in accordance with some example embodiments of the present disclosure;

[0018] FIG. 10 illustrates a flowchart of a method implemented at a first apparatus in accordance with some example embodiments of the present disclosure;

[0019] FIG. 11 illustrates a flowchart of a method implemented at a first apparatus in accordance with some example embodiments of the present disclosure;

[0020] FIG. 12 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

[0021] FIG. 13 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

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

[0023] Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. Embodiments described herein can be implemented in various manners other than the ones described below.

[0024] In the following description and claims, unless defined otherwise, all technicaland scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

[0025] References in the present disclosure to “one embodiment,” “an embodiment,” “an example embodiment,” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0026] It shall be understood that although the terms “first,” “second,”..., etc. in front of noun(s) and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another and they do not limit the order of the noun(s). For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0027] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0028] As used herein, unless stated explicitly, performing a step “in response to A” does not indicate that the step is performed immediately after “A” occurs and one or more intervening steps may be included.

[0029] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “has”, “having”, “includes” and / or “including”, when used herein, specify the presence of stated features, elements, and / or components etc., but do not preclude the presence or addition of one or more other features, elements,components and / or combinations thereof.

[0030] As used in this application, the term “circuitry” may refer to one or more or all of the following:(a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and(b) combinations of hardware circuits and software, such as (as applicable):(i) a combination of analog and / or digital hardware circuit(s) with software / firmware and(ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and(c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0031] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0032] As used herein, the term “communication network” refers to a network following any suitable communication standards, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generationcommunication protocols, including, but not limited to, the first generation (1G), the second generation (2G), 2.5G, 2.75G, the third generation (3G), the fourth generation (4G), 4.5G, the fifth generation (5G), 5.5G, the sixth generation (6G) communication protocols, and / or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

[0033] As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, an Integrated Access and Backhaul (IAB) node, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, and so forth, depending on the applied terminology and technology. In some example embodiments, radio access network (RAN) split architecture comprises a Centralized Unit (CU) and a Distributed Unit (DU) at an IAB donor node. An IAB node comprises a Mobile Terminal (IAB-MT) part that behaves like a UE toward the parent node, and a DU part of an IAB node behaves like a base station toward the next-hop IAB node.

[0034] The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE), a Subscriber Station (SS), a Portable Subscriber Station, a Mobile Station (MS), or an Access Terminal (AT). The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE), laptop -mountedequipment (LME), USB dongles, smart devices, wireless customer-premises equipment (CPE), an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. The terminal device may also correspond to a Mobile Termination (MT) part of an IAB node (e.g., a relay node). In the following description, the terms “terminal device”, “communication device”, “terminal”, “user equipment” and “UE” may be used interchangeably.

[0035] As used herein, the term “resource,” “transmission resource,” “resource block,” “physical resource block” (PRB), “uplink resource,” or “downlink resource” may refer to any resource for performing a communication, for example, a communication between a terminal device and a network device, such as a resource in time domain, a resource in frequency domain, a resource in space domain, a resource in code domain, or any other combination of the time, frequency, space and / or code domain resource enabling a communication, and the like. In the following, unless explicitly stated, a resource in both frequency domain and time domain will be used as an example of a transmission resource for describing some example embodiments of the present disclosure. It is noted that example embodiments of the present disclosure are equally applicable to other resources in other domains.

[0036] FIG. 1 illustrates an example communication network 100 in which example embodiments of the present disclosure can be implemented. As shown in FIG. 1, the communication network 100 may comprise a first apparatus 110 which may also be, for example, referred to as a terminal device or a UE.

[0037] The communication network 100 may further comprise a second apparatus 120, which may be, for example, considered as being a network device or being included in a network device. In some example embodiments, the network device may be discussed as a BS, a gNB, or an eNB.

[0038] A serving area provided by the second apparatus 120 is called a cell. The second apparatus 120 may provide one or more cells serving the first apparatus. For example, the first apparatus 110 may communicate with the second apparatus 120 within the cell 102.In some scenarios, the cell 102 may be considered as a cell that is serving the first apparatus 110.

[0039] In the following, for the purpose of illustration, some example embodiments are described with the first apparatus 110 operating as a terminal device and the second apparatus 120 operating as a network device. However, in some example embodiments, operations described in connection with a terminal device may be implemented at a network device or other device, and operations described in connection with a network device may be implemented at a terminal device or other device.

[0040] In some example embodiments, if the first apparatus 110 is a terminal device and second apparatus 120 is a network device, a link from the second apparatus 120 to first apparatus 110 is referred to as a downlink (DL), while a link from the first apparatus 110 to second apparatus 120 is referred to as an UL. In DL, the second apparatus 120 is a transmitting (TX) apparatus (or a transmitter) and the first apparatus 110 is a receiving (RX) apparatus (or a receiver). In UL, the first apparatus 110 is a TX apparatus (or a transmitter) and the second apparatus 120 is an RX apparatus (or a receiver).

[0041] It is to be understood that the number of devices and their connections shown in FIG. 1 are only for the purpose of illustration without suggesting any limitation. The communication environment 100 may include any suitable number of devices configured to implementing example embodiments of the present disclosure. Although not shown, it would be appreciated that one or more additional devices may be located in the cell 102, and one or more additional cells may be deployed in the communication environment 100. It is noted that although illustrated as a network device, the network device 120 may be another device than a network device. Although illustrated as a terminal device, the terminal device 110 may be another device than a terminal device.

[0042] In the following, for the purpose of illustration, some example embodiments are described with the terminal device 110 operating as a UE and the network device 120 operating as abase station. However, in some example embodiments, operations described in connection with a terminal device may be implemented at a network device or other device, and operations described in connection with a network device may be implemented at a terminal device or other device.

[0043] Communications in the communication environment 100 may be implemented according to any proper communication protocol(s), comprising, but not limited to,cellular communication protocols, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and / or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiple (OFDM), Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and / or any other technologies currently known or to be developed in the future.

[0044] In some discussed schemes, some aspects related to mobility enhancements have been discussed, i.e., enhancements to a handover or cell switch procedure, LTM, with event-based or event-triggered or event-driven (LI) measurement reporting. Event-triggered reporting, event -triggered LI measurement reporting, and event-triggered measurement reporting are used interchangeably herein. Some mobility enhancements related to the above-mentioned schemes are shown in the following:• Measurements related enhancements for purpose of supporting LTM:Measurement related enhancements are applicable to Intra-Central Unit (CU) Master Cell Group (MCG) / Secondary Cell Group (SCG) LTM and Inter-CU MCG / SCG LTM Specify necessary components to support event triggered LI measurement reporting Specify support for Channel State Information-Reference Signal (CSLRS) measurements for LTM procedures and enable CSLRS based beam management Specify CSI acquisition on candidate cell(s) based on CSLRS before or during LTM cell switchNOTE: Some discussed schemes may comprise a decision on whether to support CSI report before or during the LTM cell switch, as part of the CSI acquisition procedure.

[0045] Regarding the event -based / triggered-Ll measurement reporting for LTM, the discussion on event-triggered LI measurement reporting for LTM has been started, and some agreements have been discussed in some previous schemes, which are shown in the following:• LI LTM measurement event configuration is associated with LI measurement resource configuration provided in LTM configuration via Radio Resource Control (RRC) signaling.• Event triggered LI measurement should be designed for the following LTM purposes: Select the candidate beam / cell to trigger early synchronization.Select the target beam / cell and trigger LTM cell switch procedure.• For event triggered LI measurement, use of beam level measurement result for event evaluation is baseline.• Support the following LTM events based on beam specific quality of serving cell and candidate cells as the LI LTM measurement events.Event LTM2: Beam of serving cell becomes worse than an absolute threshold;Event LTM3: Beam of candidate cell becomes amount of offset better than beam of a serving cell;Event LTM4: Beam of candidate cell becomes better than an absolute threshold; Event LTM5: Beam of serving cell becomes worse than absolute thresholdl and Beam of candidate cell becomes better than another absolute threshold2.• Support the beam config of both Synchronization Signal Block (SSB) and CSLRS in LI measurement resource configuration in LTM config.• For LTM event evaluation, Time to Trigger (TTT), hysteresis for entering / leaving, and / or beam specific offset can be applied.• Current beam (i.e. a beam corresponding to the indicated Transmission Configuration Indication (TCI) state) is used for event evaluation in LI measurement reporting for serving cell.• Any beam in candidate RS configuration can be used for LTM event evaluation. • Beam level measurement result, not cell level measurement result, is used LTM event evaluation.LTM event triggered measurement configuration can be taken as baseline:LTM measurement resource configuration is provided in LTM-config.Event triggered report config is provided in serving cell config.• Medium Access Control (MAC) layer handles the event evaluation and measurement report triggering.• For measurement resource configuration, LTM CSI resource configuration is reused if possible.• For measurement reporting configuration, LTM-CSI-ReportConfig is reused if possible.• For association between measurement resource configuration and measurement reporting configuration, LTM way is reused if possible.• The entire event evaluation procedure is handled by MAC based on the latest LI measured results reported by LI.• TTT operates only based on a timer (like TTT used in L3 event triggered Measurement Report (MR)).• Same RS type should be used for both serving and neighboring cell for event LTM3 and event LTM5.• TTT is evaluated per beam, and measurement report is only triggered by beam that has satisfied the condition (entering / leaving) for the whole duration of TTT.• TTT timer is not restarted if the current beam changes and the entering condition is still met with the new current beam.• TTT is applied to the leaving condition.• Network can configure which RS type (SSB or CSLRS) is used for LTM event evaluation.Either CSLRS or SSB could be configured as candidate beam and the measurement RS of the serving cell beam is determined based on the candidate beam to ensure same RS type, i.e. the RS for current beam of serving cell is same as or Quasi Co-Located (QCLed) with the Quasi Co-Location Reference Signal (QCL RS) of the indicated TCI state.• Synchronization Signal and Physical Broadcast Channel Block Resource Indicator (SSBRI) and CSI-RS Resource Indicator (CRI) are used to represent the candidate beam Identification (ID) in LTM MR MAC CE.• For event-triggered LI LTM measurement reporting, max N is total number of all beams included into MR MAC CE.• For event-triggered LI LTM measurement reporting, Network (NW) controls if the beam(s) not satisfying the event could be reported according to N beams in MR MAC CE.• A single MAC CE format for the event -triggered LI measurement report is used for both the SSB and CSI-RS reference signals.• Support the truncated measurement report MAC CE• For gNB scheduled reporting and event triggered reportingAt least periodic CSI-RS is supported for Layer 1 Reference Signal Received Power (Ll-RSRP) measurement for candidate cellAt least CSI-RS for beam management is supported for Ll-RSRP measurement for candidate cell• The RSs of the candidate cell(s) for event evaluation are explicitly configured

[0046] LTM is a cell switch procedure, where UE’s serving cell (Primary Cell (PCell) or Primary Secondary Cell (PSCell)) is switched by the network by sending an LTM cell switch command. An LTM switch command is currently assumed delivered by MAC signaling using a MAC CE. Hence, not using RRC signaling as a L3 based handover which is one of the current methods for changing between cells. LTM cell switch decision is based on measurements (for example LI measurements) that are performed and reported (for example LI measurement report) by the UE. Measurements and reporting are based on LTM candidate cell configuration provided by the network for one or more LTM candidate cells. An LTM candidate cell may be neighboring cells or a UE’ s current serving cells (e.g. one of the current secondary cell).

[0047] In some discussed schemes, LTM measurements on a neighboring candidate cell are performed using SSBs transmitted by the candidate cell for which the SSBconfiguration is provided to the UE.

[0048] Before the cell switch, network may optionally activate one or more TCI state(s) for one or more candidate cells for early Downlink (DL) synchronization. Once a candidate cell TCI state is activated the UE may start tracking the downlink time / frequency synchronization using the reference signals associated with the activated TCI state(s). The UE may also perform early Uplink (UL) synchronization before the cell switch if this is requested by the network.

[0049] Reference is now made to FIG. 2, which shows a signaling chart for the LTM procedure. Specifically, FIG. 2 shows a scenario of Intra-CU LTM handover between UE 202 and gNB 204.

[0050] Firstly, at block 205, the UE 202 may be in an RRC CONNECTED mode, meaning that the UE 202 is connected to the gNB 204. Then, the UE 202 may send (210) a MeasurementReport message to the gNB 204. The gNB 204 may decide to configure LTM and initiate LTM preparation. At block 215, the gNB 204 may perform the LTM candidate preparation.

[0051] After performing the LTM candidate preparation, the gNB 204 may transmit (220) an RRCReconfiguration message to the UE 202 including the LTM candidate configurations. The UE 202 may store the LTM candidate configurations and transmit (225) an RRCReconfigurationComplete message to the gNB 204. The UE 202 may perform the DL synchronization with the candidate cell(s) (via early TCI activation) before receiving the cell switch command.

[0052] The UE 202 may, at step 230 and 235, perform early Timing Advance (TA) acquisition with the candidate cell(s) as requested by the network (i.e., gNB 204) before receiving the cell switch command. This is done via Contention-Free Random Access (CFRA) triggered by a Physical Downlink Control Channel (PDCCH) order from the source cell, following which the UE 202 sends preamble towards the indicated candidate cell.

[0053] At this step, in order to minimize the data interruption of the source cell due to CFRA towards the candidate cell(s), the UE 202 may not receive random access response from the network for the purpose of TA value acquisition and the TA value of the candidate cell is indicated in the cell switch command. The UE 202 may not maintain theTA timer for the candidate cell and relies on network implementation to guarantee the TA validity.

[0054] The UE 202 may perform LI measurements on the configured candidate cell(s) and transmit (240) LI measurement reports to the gNB 204. LI measurement should be performed as long as RRC reconfiguration (at step 220) is applicable.

[0055] The gNB 204 may, at block 245, decide to execute cell switch to a target cell. Then the gNB 204 may transmit (250) a cell switch command MAC CE triggering cell switch by including the candidate configuration index of the target cell. The UE 202, at block 255, may switch to the target cell and apply the configuration indicated by candidate configuration index.

[0056] The UE 202 may perform (260) the random-access procedure towards the target cell, if UE 202 does not have valid TA of the target cell. Finally, the UE 202 may complete (265) the LTM cell switch procedure by sending RRCReconfigurationComplete message to target cell. For RACH-based LTM, if the UE 202 has performed a RA procedure in step 260, the UE 202 may consider that LTM cell switch execution is successfully completed when the random-access procedure is successfully completed. For RACH-less LTM, the UE 202 may consider that LTM cell switch execution is successfully completed when the UE 202 determines that the network has successfully received its first UL data.

[0057] The steps 230-265 can be performed multiple times for subsequent LTM using the LTM candidate configuration(s) provided in step 220. The procedure over the air interface described with reference to FIG. 2 is applicable to both intra-gNodeB-Distributed Unit Ll / 2 triggered mobility (intra-gNB-DU LTM) and inter-gNodeB-Distributed Unit Ll / 2 triggered mobility (inter-gNB-DU LTM). The overall LTM procedures over Fl-C interface are captured in some discussed schemes.

[0058] Regarding the CSI reference resource, the CSI reference resource for a serving cell, i.e., for measurements which are reported to the serving cell using LI measurement reporting of type periodic, semi-persistent (SP), or aperiodic, is defined as shown in the following:In the frequency domain, the CSI reference resource is defined by the group of downlink physical resource blocks corresponding to the band to which the derived CSI relates.- In the time domain, the CSI reference resource for a CSI reporting in uplink slot n' is defined by a single downlink slotn ncsi_ref ^offset '2^KOffset’ where ^offset is a parameter configured by higher layer as specified in clause 4.2 of [6 TS 38.213], and where / J.Koffsetis the subcarrier spacing configuration for K0^setwith a value of 0 for frequency range 1,- where fiULarethe subcarrier spacing configurations for DL and UL, respectively, and N^ot offsetand / ^offset are determined by higher-layer configured ca-SlotOffset for the cells transmitting the uplink and downlink- where for periodic and semi-persistent CSI reporting- if a single CSI-RS / SSB resource is configured for channel measurement ncsi _re / is the smallest value greater than or equal to 4 • 2kDL, such that it corresponds to a valid downlink slot, or- if multiple CSI-RS / SSB resources are configured for channel measurement ncsi _re / is the smallest value greater than or equal to 5 • 2^, such that it corresponds to a valid downlink slot.- where for aperiodic CSI reporting, if the UE is indicated by the Downlink Control Information (DCI) to report CSI in the same slot as the CSI request, ncsi _re / is such that the reference resource is in the same valid downlink slot as the corresponding CSI request, otherwise ncsi _re / is the smallest value greater than or equal tosuch that slot n- ncsi_ref corresponds to a valid downlink slot, where Z' corresponds to the delay requirement in some discussed schemes.- when periodic or semi-persistent CSI-RS / CSI Interference Measurement (CSI-IM) or SSB is used for channel / interference measurements, the UE is not expected to measure channel / interference on the CSI-RS / CSI-IM / SSB whose last OFDM symbol is received up to Z' symbols before transmission time of the first OFDM symbol of the aperiodic CSI reporting.

[0059] A slot in a serving cell shall be considered to be a valid downlink slot if certain conditions are met, wherein the conditions mentioned herein are shown in the following:Conditions:- it comprises at least one higher layer configured downlink or flexible symbol, and - it does not fall within a configured measurement gap for that UE

[0060] If there is no valid downlink slot for the CSI reference resource corresponding to a CSI Report Setting in a serving cell, CSI reporting is omitted for the serving cell in uplink slot n'.

[0061] For a CSI report with reportQuantity not set to ‘ ssb-Index-RSRP\ ‘ ssb-Index-SINR' , ‘ s sb -Index-RSRP -Index' or "ssb- Index-SINR-Index' , after the CSI report (re)configuration, serving cell activation, Bandwidth Part (BWP) change, or activation of Semi-Persistent CSI (SP-CSI), the UE reports a CSI report only after receiving at least one CSI-RS transmission occasion for channel measurement and CSI-RS and / or CSI-IM occasion for interference measurement no later than CSI reference resource and drops the report otherwise.

[0062] For a CSI report configuration containing a list of sub-configurations provided by csi-ReportSubConfigToAddModList, after the CSI report (re)configuration, serving cell activation, BWP change, or activation of Semi-Persistent CSI (SP-CSI), the UE reports a CSI report including one or more sub-reports only after receiving at least one CSI-RS transmission occasion for channel measurement and CSI-RS and / or CSI-IM occasion for interference measurement, per sub-configuration, no later than CSI reference resource and drops the report otherwise, where the sub-configuration is the activated / triggered one for Aperiodic / Semi-Persistent CSI (AP / SP-CSI) reporting, or the configured one for Periodic CSI (P-CSI) reporting.

[0063] Regarding the Ll-RSRP reporting, if the higher layer parameter timeRestrictionForChannelMeasurements in CSI-ReportConfig s set to "notConfigured" , the UE shall derive the channel measurements for computing Ll-RSRP value reported in uplink slot n based on only the SS / PBCH or NZP CSI-RS, no later than the CSI reference resource, associated with the CSI resource setting.

[0064] If the higher layer parameter timeRestrictionForChannelMeasurements in CSI-ReportConfig is set to "Configured" , the UE shall derive the channel measurements for computing Ll-RSRP reported in uplink slot n based on only the most recent, no later thanthe CSI reference resource, occasion of SS / PBCH or Non-Zero Power CSI-RS (NZP CSI-RS) associated with the CSI resource setting.

[0065] Reference is now made to FIG. 3, which shows an example of CSI reference resource for a periodic reporting using the ncsi _ref aforementioned.

[0066] According to FIG. 3, the UE may determine a part of the RSs or a part of the measurements performed before the CSI reference resource as valid measurement resource or measurement occasions for a periodic reporting.

[0067] In some discussed schemes, an event-triggered reporting is being considered for reporting of LI measurements for both BM (for MIMO purposes) and LTM (for cell switch purposes), where the UE will be configured with events to determine when to send a report containing one or more measurements. For example, an event may be configured where the UE is required to evaluate the quality of a candidate beam / RS (e.g., for LTM this would be an RS transmitted from a candidate cell) against a threshold, or the quality of the current beam (RS associated with the current serving beam) being used by the UE in the current serving cell.

[0068] For cell switch, MAC CE (e g., LTM Measurement Report (MR) MAC-CE) is selected as a reporting medium for event triggered LI measurement results. Layer 1 sends the measurements to the Layer 2 (MAC), and MAC layer runs the event evaluation. The event triggered report may be triggered when at least one RS (i.e. serving RS / beam or candidate RS / beam) fulfills the reporting criteria (such as LTM 2 / 3 / 4Z5) for the duration of the TTT. When TTT expires and the RS has fulfilled the condition for the TTT duration, an LTM MR (LTM measurement report) MAC CE is triggered to convey the RS information to network.

[0069] A TTT (time to trigger) is agreed to be run on RS / beam level i.e. for each of the RS / beam associated with an event triggered reporting, a TTT may be used separately.

[0070] For the Layer 1 measurement reporting, CSI reference resource is defined to determine the valid measurement (RS) occasions (i.e., RSs no later than the DL slot overlapping with CSI reference resource) for reporting. Based on that, for a reporting slot, the UE may determine whether a report can be dropped, depending on the position of the Measurement Reference Signal (meas RS) occasion(s) relative to the CSI Refence Resource. In some cases (e.g., in periodic and SP reporting), this is also used to determinereference timing of the occupancy of the CSI processing unit associated with that report.

[0071] For the periodic / SP / aperiodic reporting, the CSI reference is typically determined with respect the uplink reporting slot timing. However, for MAC CE based event triggered reporting or any other reporting when the reporting is triggered only when the event is met, the existing definition for CSI reference resource for periodic / SP / aperiodic reporting can’t be applied.

[0072] The scheme for determining the CSI reference resource and performing the event triggered layer 1 measurement reporting such that appropriate set of measurements or RS occasions can be determined for a reporting is desirable.

[0073] In accordance with some example embodiments of the present disclosure, there is provided a solution for defining CSI reference resource for measurement reporting. In this solution, a message at least comprising configuration information associated with a time to trigger (TTT) is received by the first apparatus 110. For example, the configuration information can contain the information of the value of the maximum time or duration a TTT should run. A TTT duration prior to a slot associated with an event-triggered measurement reporting is determined based on the configuration information. The TTT duration is associated with a RS or a beam to be measured for an event-triggered measurement reporting. The first apparatus 110 determines CSI reference resource for the event-triggered measurement reporting based at least on the TTT duration.

[0074] In this way, CSI reference resource can be defined for a MAC-CE based event triggered reporting or a reporting which considers a timer (similar to TTT) based event evaluation to determine whether a reporting needs to be triggered, and valid RS occasions can also be defined for event evaluation for such reporting. Thus, a higher efficiency for performing the event triggered reporting can be achieved. Furthermore, a higher flexibility for performing measurements and transmitting the measurement report can also be realized. Furthermore, both first apparatus where the measurements are performed and second apparatus to which the measurements are reported, can have same understanding of measurements or RS occasions used for reporting.

[0075] The proposed method according to the present disclosure has key aspects that for an event triggered layer 1 measurement reporting, especially, when the reporting is performed using the layer 2 MAC CE container or using an event evaluation based on a timer (such as TTT) to determine whether to trigger a reporting, two aspects areconsidered: for the first aspect, it is proposed that the CSI reference resource is determined based on a time to trigger (TTT) timer duration, or any other timer or counter used for event evaluation, associated with the report; for the second aspect, it is proposed that the valid RS occasions or measurements for an event evaluation for a RS are determined based on the CSI reference resource or a time to trigger (TTT) timer duration associated with the report. The embodiments of the present disclosure are presented using the time to trigger (TTT) timer duration, however, all the embodiments are not limited to only to a TTT and can be applied to any other timer or counter used for event evaluation to determine whether to trigger a reporting.

[0076] It should be noted that the solutions proposed herein can be applied to any measurement reporting or used for any purpose (including but not limited to cell switching), where a TTT or any similar counter (any counter or timer) based evaluation can be used to trigger a measurement report.

[0077] Example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0078] FIG. 4 shows a signaling chart 400 related to the process of determining the CSI reference resource according to some example embodiments of the present disclosure. FIG. 5 shows an example diagram related to the timeline of determining the CSI reference resource at the end of the TTT duration. FIG. 6 shows an example diagram related to the timeline of determining the CSI reference resource with a gap from the end of the TTT duration.

[0079] Reference is now made to FIG. 4, which shows a signaling chart 400 for communication according to some example embodiments of the present disclosure. As shown in FIG. 4, the signaling chart 400 involves a first apparatus 110, a second apparatus 120 and a candidate cell 130. For the purpose of discussion, reference is made to FIG.1, FIG. 5 and FIG. 6 to describe the signaling chart 400. The signaling chart 400 is related to the determination of the TTT duration and the CSI reference resource.

[0080] In the scenario shown in FIG. 4, the candidate cell 130 may be a cell that can be switched to during the LTM process, and the second apparatus 120 may also be referred to as a serving cell (or a network device) currently serving the first apparatus 110. Furthermore, in this scenario the first apparatus 110 may also be referred to as a UE (or a terminal device) as well.

[0081] As shown, the first apparatus 110 may receive (405), from a second apparatus 120, a message at least comprising configuration information associated with a TTT. For example, the configuration information may indicate to the first apparatus 110 a value for which a TTT should run, or a time point / a condition to start a TTT timer for at least one TTT duration.

[0082] In some embodiments, the message received by the first apparatus 110 may be an RRC configuration message. While in some other embodiments the message may be an RRC reconfiguration message. Furthermore, the message may also indicate a gap for determining the CSI reference resource.

[0083] In some embodiments, in addition to the configuration information associated with the TTT, it is possible that the RRC configuration message may also comprise an event-triggered measurement reporting configuration and / or a configuration of one or more RS occasion. Alternatively, in some further embodiments, the message may be an activation command associated with a RS transmission associated with the event-triggered reporting or an activation command activating the event-triggered reporting.

[0084] In some embodiments, the first apparatus 110 may also receive, via the message, an indication of one or more occasions of an RS or the beam, such as an SSB or a CSI-RS, to be measured. As an example, as shown in FIG. 5, the message received by the first apparatus 110 may also indicate at least one occasion for the RS 506, RS 508, RS 510 and RS 512 for performing measurements. For example, the message may contain the configuration information of RS to be measured for the event-triggered reporting such as at least the time domain information to indicate the time locations or occasions, like periodicity, of the RS.

[0085] After receiving the message, the first apparatus 110 may transmit (410), to the second apparatus 120, an acknowledgement of the message indicating that the message comprising the configuration information is correctly received.

[0086] Then, the first apparatus 110 may determine a TTT duration prior to a slot associated with an event-triggered measurement reporting (e.g., an UL slot) based on the configuration information of the TTT.

[0087] In some embodiments, the TTT duration mentioned herein may be related to one measurement RS or beam. On the other hand, the TTT duration may also be related to allmeasurement RSs or beams that the first apparatus 110 has received.

[0088] In some embodiments, as a first option for determining the TTT duration, the TTT duration may be associated with a RS or a beam to be measured for an event-triggered measurement reporting. In other words, the TTT duration may be determined separately per measurement RS / beam (e.g., SSB or CSI-RS) associated with the event triggered layer 1 measurement reporting.

[0089] For example, the TTT duration may be determined differently based on the type of the RS or a type of the RS / beam. As an example, a TTT duration associated with a RS / beam from the second apparatus 120 may be different from a TTT duration associated with a RS / beam from the candidate cell 130.

[0090] In some embodiments, as a second option for determining the TTT duration, the TTT duration is associated with a plurality of RSs or beams to be measured. The TTT duration may also be associated with per event type or reporting configuration associated with the event-triggered measurement reporting. In other words, the TTT duration may be determined per resource set, e.g., across all measurement RSs / beams, or per event type or per report configuration associated with the event-triggered LI measurement reporting.

[0091] In some embodiments, the TTT duration may overlap with at least one DL slot. As an example, the overlapped DL slot may be used as the slot for transmitting the CSI reference resource.

[0092] In some embodiments, the TTT duration may comprise a slot or a symbol in the slot where a TTT timer is expected to expire and a condition for the event-triggered measurement reporting is still fulfilled. As an example, at time point 520 as shown in FIG.5, the TTT timer is expected to expire and a DL slot allocated for the CSI reference resource may be located at time point 520.

[0093] In some embodiments, the TTT duration may correspond to the latest TTT in a plurality of TTTs. As an example, in the scenario shown in FIG. 5, there are two TTTs, namely TTT 502 and TTT 504. In the scenario shown in FIG. 5, the latest TTT may be the TTT 504 since this TTT is the most recent TTT started by the TTT timer.

[0094] In some embodiments, the determination of the latest TTT may be defined to the first apparatus 110 where the first apparatus 110 may consider the latest TTT to be the latest TTT duration that overlaps with at least one DL slot.

[0095] In one example, the TTT duration may be defined as the slot or the first / last symbol of the slot where the TTT is expected to expire if the reporting criteria is fulfilled still.

[0096] In some embodiments, the latest TTT mentioned herein may be related to one measurement RS or beam. On the other hand, the latest TTT may also be related to all measurement RSs or beams that the first apparatus 110 has received.

[0097] In some embodiments, as in the first option for determining the TTT duration, the latest TTT may be the latest TTT for one measurement RSs / beam or the latest TTT may be the latest TTT for one measurement RSs / beam that overlaps with the at least one DL slot. On the other hand, as in the second option for determining the TTT duration, the latest TTT may be the latest TTT duration across all measurement RSs / beams (e.g., the largest TTT duration) or the latest TTT may be the latest TTT duration across all measurement RSs / beams (e.g., the largest TTT duration) that overlaps with the at least one DL slot.

[0098] As described above, the TTT duration is prior to a slot associated with the event-triggered measurement reporting. In some other embodiments, the slot may be the first UL slot carrying an uplink control or data transmission after the latest TTT duration in the at least one TTT duration.

[0099] In some embodiments, the slot for the event triggered reporting as mentioned above may be an available UL slot after the TTT duration for carrying an uplink signal for requesting uplink resources for the event -triggered measurement reporting. For example, the UL slot may be the next available UL slot carrying the UL signal, i.e., scheduling request (SR), to indicate the event triggered reporting is triggered and requesting the UL resource for the report (two step reporting).

[0100] In some other embodiments, the slot may be an available UL slot after the TTT duration for carrying the event-triggered measurement reporting.

[0101] For example, the UL slot may be the next UL slot carrying the MAC CE (for one step report, when the UL resources are available, and there is no need of SR) associated with the event triggered reporting. In the above scenario, since the gNB (i.e., the second apparatus 120) will know about the reporting slot after receiving the report, the gNB may need to derive the CSI ref resource once it receives the report.

[0102] In yet another example, the UL slot may be the first UL slot after each latest TTT duration or the first UL slot carrying the Physical Uplink Shared Channel (PUSCH) or Physical Uplink Control Channel (PUCCH) after each latest TTT.

[0103] In other words, from the perspective of the second apparatus 120, a potential CSI reference resource is assumed with respect to the latest TTT duration and UL slot that comes after the latest TTT duration. The first apparatus 110 may or may not have a report or related information always in this UL slot.

[0104] Also, the second apparatus 120 may not expect an event report before ending of a latest TTT duration. When the UL slot is not fixed and cannot be determined before the reporting is triggered / performed, the first apparatus 110 and the second apparatus 120 may have the common understanding on the UL slot which can be used to determine the CSI reference resource beforehand at both the first apparatus 110 and the second apparatus 120 side.

[0105] Based on the configuration information of TTT, the first apparatus 110 may start (415) a TTT timer of the first TTT after processing the event-triggered measurement reporting configuration. For example, a TTT timer for a measurement RS / beam may start after the processing the RRC (re-)configuration containing the event triggered measurement reporting configuration (e.g., after sending the acknowledgment and processing RRC (re ^configuration command).

[0106] Alternatively, the first apparatus 110 may start the TTT timer of the first TTT after a processing of an activation command for activating the event-triggered measurement reporting configuration. For example, a TTT timer may start after the processing of the activation command activating the event triggered measurement reporting configuration (if the event triggered reporting is activated via layerl / layer2 control signaling). Alternatively, the first apparatus 110 may start the TTT timer of the first TTT after a processing of an activation command (layerl / layer2 control signaling) for activating the measurement on at least an RS or at least an RS associated with the event-triggered measurement reporting.In some embodiments, the first apparatus 110 may start, from the first symbol of the one or more occasions, the TTT timer of the first TTT in the plurality of TTTs. For example, a TTT start time for a measurement RS / beam may be defined to the first apparatus 110 from the first symbol of the earliest occasion of the measurement RS resource. As shownin FIG. 5, the first apparatus 110 may start the TTT timer of the first TTT from the first symbol of occasion 514.

[0107] As an option, the first apparatus 110 may restart the TTT timer for the second TTT upon an expiry of the first TTT. That is, the restart of the TTT timer may be upon the expiry of the previous TTT.

[0108] As shown in FIG. 5, the first apparatus 110 may restart (430) the TTT timer of a second TTT (e.g. the TTT 504 in FIG. 5) subsequent to the first TTT (e.g. the TTT 502 in FIG. 5).

[0109] In one option, the first apparatus 110 may restart the TTT timer for the second TTT associated with an RS or a beam upon the expiry of the first or previous TTT associated with the RS or beam. As another option, the first apparatus 110 may restart the TTT timer for an RS or a beam for the second TTT upon an expiry of all first TTTs associated with all RSs or beams to be measured for the event-triggered measurement reporting. For example, the restart of the TTT timer may be upon the expiry of all TTTs associated with event report configuration (e.g., upon the expiry of the TTT with the largest duration).

[0110] After starting the TTT timer, the first apparatus 110 may determine (420) a CSI reference resource for the event-triggered measurement reporting based at least on the TTT duration. For example, for an event triggered layer 1 measurement reporting, the first apparatus 110 may determine a CSI reference resource based on a TTT timer duration associated with the report.[OHl] In some embodiments, as an option, the first apparatus 110 may determine the most recent DL slot, that is no later than an end of the TTT duration, as the CSI reference resource. For example, the CSI reference resource is defined by considering a latest TTT associated with the report that ended prior to the UL slot (shown in FIG. 5).

[0112] For example, the CSI reference resource is the most recent DL slot no later than the ending of TTT duration of the latest TTT associated with the report that ended prior to the UL slot (UL slot carrying the SR or MAC-CE or measurement report, or UL slot scheduled to carry any UL control or data after the TTT duration).

[0113] In some other embodiment, as a second option for determining the DL slot for CSI reference resource, the first apparatus 110 may determine the most recent DL slotwith at least a gap before the end of the TTT duration, as the CSI reference resource (shown in FIG. 6). The gap may comprise at least one symbol or at least one slot determined based on at least one of a capability of the first apparatus, a reporting quantity associated with the event-triggered measurement reporting, or the event-triggered measurement reporting configuration.

[0114] As shown in FIG. 6, the DL slot determined to be the slot for the CSI reference resource is prior to the end of the TTT duration with a gap “X”.

[0115] In some embodiments, the gap comprises at least one symbol or at least one slot. For example, the CSI Reference Resource is the most recent DL slot which is at least X symbols / slots before the ending of TTT duration of the latest TTT associated with the report that ended prior to the UL slot (UL slot carrying the SR or MAC-CE or measurement report, or UL slot scheduled to carry any UL control or data after the TTT duration).

[0116] In some embodiments, the first apparatus 110 may determine the gap based on the capability of the first apparatus 110 or a reporting quantity associated with the measurement report for the event-triggered reporting. For example, the value of X may be based on the capability of the first apparatus 110.

[0117] In some other examples, the value of X may be a function of CSI computation delay / time where the CSI computation time may be determined based on the capability of the first apparatus 110 and the reporting quantity (e.g., Ll-RSRP, Layer 1 Signal to Interference plus Noise Ratio (Ll-SINR), etc.). For example, X may equal to or larger than the CSI computation delay / time.

[0118] In some embodiments, the first apparatus 110 may obtain a configuration of the gap from an event-triggered measurement reporting configuration. For example, the value of X may be configured to the first apparatus 110 (e.g., as a part of the event triggered LI measurement reporting configuration).

[0119] In some embodiments, if a periodic reporting is configured for the event-triggered measurement reporting, the first apparatus 110 may determine the CSI reference resource for the first periodic reporting or first reporting instance of the event-triggered measurement reporting based at least on the TTT duration.

[0120] For example, for the event triggered layer 1 measurement reporting, when theperiodic reporting is configured, an initial report may be triggered when a configured event is met. For the periodic reports associated with the event triggered layer 1 measurement reporting (excluding an initial event triggered report triggered when a configured event is met) the CSI reference resource may be determined based on the UL slot carrying the report (e.g., not based on the TTT duration).

[0121] In some embodiments, if a report on leave is configured for the event-triggered measurement reporting, the first apparatus 110 may determine the CSI reference resource for the event-triggered measurement reporting triggered due to report on leave. For example, a report on leave is triggered when an RS or a beam which met the condition in the past and triggered a report, now does not meet the condition any more, therefore a repot may be sent to indicate that the RS / beam does not meet the condition of reporting.

[0122] After determining the CSI reference resource, the first apparatus 110 may perform (425) measurement on the second apparatus 120 and the candidate cell 130 (if any).

[0123] After the TTT duration is expired, the first apparatus 110 may determine (435) whether at least one reporting event is met or triggered for the valid measurements or RS occasions. The details related to the valid measurements and RS occasions will be described below with reference to FIG. 7.

[0124] If the reporting event is met, the first apparatus 110 may transmit (440) a scheduling request requesting uplink resources for transmitting the measurement report. Then the first apparatus 110 may receive (445) the UL resource allocation from the second apparatus 120. Based on the UL resource allocation, the first apparatus 110 may send (450) the LTM measurement report to the second apparatus 120 via, for example, a MAC-CE message.

[0125] It is also possible that the first apparatus 110 may transmit the measurement report without requesting the UL resource allocation, if the UL resources are available.

[0126] FIG. 7 shows a signaling chart 700 related to the process of determining valid measurements or RS occasions according to some example embodiments of the present disclosure.

[0127] Reference is now made to FIG. 7, which shows a signaling chart 700 for communication according to some example embodiments of the present disclosure. As shown in FIG. 7, the signaling chart 700 involves a first apparatus 110, a second apparatus120 and a candidate cell 130. For the purpose of discussion, reference is made to FIG.1, FIG. 5 and FIG. 6 to describe the signaling chart 700. The signaling chart 700 is related to the determination of valid RS measurements or valid RS occasions for event evaluation.

[0128] In the scenario shown in FIG. 7, the overall process for determining the TTT duration and a slot for the CSI reference resource is similar to the scenario shown in FIG.4, thus the details will not be repeated herein.

[0129] As shown in FIG. 7, the first apparatus 110 may receive (705), from a second apparatus 120, a message at least comprising configuration information associated with a TTT. The configuration information may also indicate directly or indirectly a certain number of RS measurements or RS occasions that are used for event evaluation. Alternatively or in addition, the configuration information may also indicate a time period that is associated with the valid RS measurements or RS occasions.

[0130] In some embodiments, the TTT duration is associated with a plurality of RSs or beams to be measured. Alternatively, the TTT duration is associated with a RS or a beam to be measured.

[0131] The first apparatus 110 may transmit (710) an acknowledgement to the second apparatus 120 after successfully receiving the message.

[0132] After starting (715) a TTT timer, the first apparatus 110 may determine (720) a CSI reference resource for an event-triggered measurement reporting based at least on a TTT duration that is determined based on the configuration information and at least one DL slot. It is to be understood that the determination of the CSI reference resource has been described with reference to FIGs. 4-6, which will not be repeated here.

[0133] Furthermore, the first apparatus 110 may determine (725) a channel measurement valid for an event evaluation or for reporting. Alternatively or in addition, the first apparatus 110 may determine a channel measurement valid for reporting for the event-triggered measurement reporting based at least on the CSI reference resource.

[0134] In some embodiments, as the first option for determining the valid channel measurement, the first apparatus 110 may determine the channel measurement valid for the event evaluation based on at least one measurement made or received no later than the CSI reference resource in a time domain. For example, for an event evaluation for a measurement RS associated with an event triggered measurement reporting, the firstapparatus 110 may use the channel measurements (e.g., Ll-RSRP, Ll-SINR, etc.) based on the measurements made / received (e.g. received by L2) no later than the CSI reference resource associated with the event triggered measurement reporting.

[0135] In other words, the measurement that is made or received prior to the CSI reference resource in a time domain or the measurement that is made or received at the same time with the CSI reference resource may be selected as valid channel measurements.

[0136] In some embodiments, the first apparatus 110 may determine the channel measurement valid for the event evaluation based on at least one measurement until a time period after the CSI reference resource in a time domain and no later than the end of the TTT duration.

[0137] For example, for an event evaluation for a measurement RS associated with an event triggered measurement reporting, the first apparatus 110 may use the channel measurements (e.g., Ll-RSRP, Ll-SINR, etc.) based on the measurements made / received until the a certain number (e.g., 3 slots or symbols) of slots / symbols after the CSI reference resource associated with the event triggered measurement reporting, but no later than the ending of the TTT duration of the latest TTT associated with RS.

[0138] In some embodiments, the first apparatus 110 may determine the channel measurement valid for the event evaluation based on at least one RS occasion no later than the CSI reference resource in a time domain. For example, for an event evaluation for a measurement RS associated with an event triggered measurement reporting, the first apparatus 110 may use the channel measurements (e.g., Ll-RSRP, Ll-SINR) based on the RS occasions no later than the CSI reference resource associated with the event triggered measurement reporting.

[0139] In some embodiments, the first apparatus 110 may determine the channel measurement valid for the event evaluation based on at least one RS occasion until a time period after the CSI reference resource in a time domain and no later than the end of the TTT duration.

[0140] Alternatively or in addition, for an event evaluation for a measurement RS associated with an event triggered measurement reporting, the first apparatus 110 may use the channel measurements (e.g., Ll-RSRP, Ll-SINR, etc.) based on the RS occasions until the a certain number (e.g., 3 slots or symbols) of slots / symbols after the CSI referenceresource associated with the event triggered measurement reporting, but no later than the ending of the TTT duration of the latest TTT associated with RS.

[0141] In some embodiments, the time period may be based on at least one of a capability of the first apparatus 110. For example, the time period may be based on the computation time required by the first apparatus 110. Alternatively, the time period may also be based on a configuration from the second apparatus 120. In some embodiment, the time period may be based on at least the reporting quantity to be computed and reported in a measurement report for the event-triggered reporting.

[0142] In some embodiments, the at least one RS occasion comprises a certain number of most recent RS occasions no later than the CSI reference resource in the time domain. In other words, for an event evaluation for a measurement RS associated with an event triggered measurement reporting, the first apparatus 110 may be further configured to consider only certain measurements or RS occasions (e.g., 3 most recent measurements or RS occasions).

[0143] For example, the first apparatus 110 may be configured to consider only a certain number of most recent occasions of the RS that are no later than the CSI reference resource.

[0144] In some embodiments, the first apparatus 110 may obtain an indication of the certain number from a configuration of the event-triggered measurement reporting. For example, the certain number may be indicated to the first apparatus 110 in the report configuration by the second apparatus 120. Another example, it may be indicated to consider only the most recent occasion to the first apparatus 110 in the report configuration by the second apparatus 120.

[0145] In some embodiments, as the second option for determining the valid channel measurement, the first apparatus 110 may determine a channel measurement valid for an event evaluation or reporting for the event-triggered measurement reporting based at least on the TTT duration.

[0146] In some embodiments, the first apparatus 110 may determine the channel measurement valid for the event evaluation or reporting based on at least one measurement no later than the end of the TTT duration.

[0147] For example, for an event evaluation for a measurement RS associated with an event triggered measurement reporting, the first apparatus 110 may use the channelmeasurements (e.g., Ll-RSRP, Ll-SINR, etc.) based on the measurements made / received no later than the ending of the TTT duration of the latest TTT associated with RS.

[0148] Alternatively or in addition, the first apparatus 110 may determine the channel measurement valid for the event evaluation or reporting based on at least one RS occasion no later than the end of the TTT duration.

[0149] For example, for an event evaluation for a measurement RS associated with an event triggered measurement reporting, the first apparatus 110 may use the channel measurements (e.g., Ll-RSRP, Ll-SINR, etc.) based on the RS occasions no later than the ending of the TTT duration of the latest TTT associated with RS.

[0150] Based on the determined valid measurements or valid RS occasions, the first apparatus 110 may perform (730) measurements on at least one of the second apparatus 120 and one or more different candidate cells.

[0151] As shown in FIG. 7, the first apparatus 110 may restart (735) the TTT timer when the previous TTT expires.

[0152] Then, the first apparatus 110 may perform (740) the event evaluation for the event-triggered measurement using the channel measurement (e.g., the valid measurements selected by the first apparatus 110 based on the first option or the second option for determining valid channel measurement).

[0153] If the reporting event is determined to be met based on the channel measurements, the first apparatus 110 may transmit (745) a scheduling request requesting uplink resources for transmitting the measurement report.

[0154] Then, the first apparatus 110 may receive (750) the UL resource allocation from the second apparatus 120.

[0155] Although the above process is described with respect to the first apparatus 110, it should be understood that the same or similar procedure of determining CSI reference resource or valid measurements may also run at the NW side (e.g., at the second apparatus 120 or at the candidate cell 130).

[0156] As shown in FIG. 7, the first apparatus 110 may send (755) the LTM measurement report to the second apparatus 120 via, for example, a MAC-CE message.

[0157] FIG. 8 shows a flowchart of an example method 800 implemented at a firstapparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 800 will be described from the perspective of the first apparatus 110 in FIG. 1.

[0158] At block 810, the first apparatus 110 receives, from a second apparatus, a message at least comprising configuration information associated with a TTT.

[0159] At block 820, the first apparatus 110 determines, based on the configuration information, a TTT duration prior to a slot associated with an event-triggered measurement reporting, wherein the TTT duration is associated with a RS or a beam to be measured for an event -triggered measurement reporting.

[0160] At block 830, the first apparatus 110 determines a CSI reference resource for the event-triggered measurement reporting based at least on the TTT duration.

[0161] In some example embodiments, the TTT duration overlaps with at least one DL slot.

[0162] In some example embodiments, the TTT duration comprises a slot or a symbol in the slot where a TTT timer is expected to expire and a condition for the event-triggered measurement reporting is still fulfilled.

[0163] In some example embodiments, the TTT duration corresponds to the latest TTT in a plurality of TTTs.

[0164] In some example embodiments, the method 800 further comprises: starting the TTT timer of the first TTT in the plurality of TTTs after processing the event-triggered measurement reporting configuration or after a processing of an activation command for activating the event-triggered measurement reporting configuration or after a processing of an activation command for activating at least an RS or at least a measurement on at least an RS to be measured for the event-triggered measurement reporting.

[0165] In some example embodiments, the method 800 further comprises: receiving, via the message, an indication of one or more occasions of the RS or the beam to be measured; and starting, from the first symbol of the one or more occasions, the TTT timer of the first TTT in the plurality of TTTs.

[0166] In some example embodiments, the method 800 further comprises: restarting the TTT timer of a second TTT subsequent to the first TTT upon at least one of: an expiry ofthe first TTT, or an expiry of all first TTTs associated with all reference signals or beams to be measured for the event -triggered measurement reporting.

[0167] In some example embodiments, the slot is an available uplink slot after the TTT duration for carrying an uplink signal for requesting uplink resources for the event-triggered measurement reporting or carrying the event-triggered measurement reporting.

[0168] In some example embodiments, the slot is a first uplink slot carrying an uplink control or data transmission after the latest TTT duration in the at least one TTT duration.

[0169] In some example embodiments, the method 800 further comprises: determining the most recent DL slot, that is no later than an end of the TTT duration, as the CSI reference resource.

[0170] In some example embodiments, the method 800 further comprises: determining the most recent DL slot with at least a gap before the end of the TTT duration, as the CSI reference resource.

[0171] In some example embodiments, the gap comprises at least one symbol or at least one slot.

[0172] In some example embodiments, the method 800 further comprises: determining the gap based on at least one of a capability of the first apparatus or a reporting quantity associated with the event-triggered measurement reporting.

[0173] In some example embodiments, the method 800 further comprises: obtaining a configuration of the gap from an event-triggered measurement reporting configuration.

[0174] In some example embodiments, the method 800 further comprises: in accordance with a determination that a periodic reporting is configured for the event-triggered measurement reporting, determining the CSI reference resource for the first periodic reporting or first reporting instance of the event-triggered measurement reporting based at least on the TTT duration.

[0175] In some example embodiments, the message comprises a radio resource control, RRC, configuration message, or an RRC reconfiguration message, or an activation command associated with a reference signal transmission.

[0176] In some example embodiments, the first apparatus comprises a terminal device and the second apparatus comprises a network device.

[0177] FIG. 9 shows a flowchart of an example method 900 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 900 will be described from the perspective of the first apparatus 110 in FIG. 1.

[0178] At block 910, the first apparatus 110 receives, from a second apparatus, a message at least comprising configuration information associated with a TTT.

[0179] At block 920, the first apparatus 110 determines, based on the configuration information, a TTT duration prior to a slot associated with an event-triggered measurement reporting, wherein the TTT duration is associated with a plurality of reference signals or beams to be measured or is per event type or reporting configuration associated with the event-triggered measurement reporting.

[0180] At block 930, the first apparatus 110 determines a CSI reference resource based at least on the TTT duration.

[0181] In some example embodiments, the TTT duration overlaps with at least one DL slot.

[0182] In some example embodiments, the TTT duration comprises a slot or a symbol in the slot where a TTT timer is expected to expire and a condition for the event-triggered measurement reporting is still fulfilled.

[0183] In some example embodiments, the TTT duration corresponds to the latest TTT in a plurality of TTTs.

[0184] In some example embodiments, the method 900 further comprises: starting the TTT timer of the first TTT in the plurality of TTTs after processing the event-triggered measurement reporting configuration or after a processing of an activation command for activating the event-triggered measurement reporting configuration or after a processing of an activation command for activating at least an RS or at least a measurement on at least an RS to be measured for the event-triggered measurement reporting.

[0185] In some example embodiments, the method 900 further comprises: receiving, via the message, an indication of one or more occasions of the reference signal or the beam to be measured; and starting, from the first symbol of the one or more occasions, the TTT timer of the first TTT in the plurality of TTTs.

[0186] In some example embodiments, the method 900 further comprises: restarting the TTT timer of a second TTT subsequent to the first TTT upon at least one of: an expiry of the first TTT, or an expiry of all first TTTs associated with all reference signals or beams to be measured for the event -triggered measurement reporting.

[0187] In some example embodiments, the slot is an available uplink slot after the TTT duration for carrying an uplink signal for requesting uplink resources for the event-triggered measurement reporting or carrying the event-triggered measurement reporting.

[0188] In some example embodiments, the slot is the first uplink slot carrying an uplink control or data transmission after the latest TTT duration in the at least one TTT duration.

[0189] In some example embodiments, the method 900 further comprises: determining a most recent DL slot, that is no later than an end of the TTT duration, as the CSI reference resource.

[0190] In some example embodiments, the method 900 further comprises: determining a most recent DL slot with at least a gap before the end of the TTT duration, as the CSI reference resource.

[0191] In some example embodiments, the gap comprises at least one symbol or at least one slot.

[0192] In some example embodiments, the method 900 further comprises: determining the gap based on at least one of a capability of the first apparatus or a reporting quantity associated with the event-triggered measurement reporting.

[0193] In some example embodiments, the method 900 further comprises: obtaining a configuration of the gap from an event-triggered measurement reporting configuration.

[0194] In some example embodiments, the method 900 further comprises: in accordance with a determination that a periodic reporting is configured for the event-triggered measurement reporting, determining the CSI reference resource for the first periodic reporting or first reporting instance of the event-triggered measurement reporting based at least on the TTT duration.

[0195] In some example embodiments, the message comprises a radio resource control, RRC, configuration message or an RRC reconfiguration message, or an activation command associated with a reference signal transmission.

[0196] In some example embodiments, the first apparatus comprises a terminal device and the second apparatus comprises a network device.

[0197] FIG. 10 shows a flowchart of an example method 1000 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 1000 will be described from the perspective of the first apparatus 110 in FIG. 1.

[0198] At block 1010, the first apparatus 110 receives, from a second apparatus, a message at least comprising configuration information associated with a TTT.

[0199] At block 1020, the first apparatus 110 determines a CSI reference resource for an event-triggered measurement reporting based at least on a TTT duration that is determined based on the configuration information and at least one DL slot, and

[0200] At block 1030, the first apparatus 110 determines a channel measurement valid for an event evaluation or for reporting for the event-triggered measurement reporting based at least on the CSI reference resource.

[0201] At block 1040, the first apparatus 110 performs the event evaluation or reporting for the event -triggered measurement based on the channel measurement.

[0202] In some example embodiments, the TTT duration overlaps with the at least one DL slot and prior to a slot associated with the event -triggered measurement reporting.

[0203] In some example embodiments, the slot is an available uplink slot after the TTT duration for carrying an uplink signal for requesting uplink resources for the event-triggered measurement reporting or carrying the event-triggered measurement reporting.

[0204] example embodiments, the slot is a first uplink slot carrying an uplink control or data transmission after the latest TTT duration in the at least one TTT duration.

[0205] In some example embodiments, the TTT duration comprises a slot or a symbol in the slot where a TTT timer is expected to expire and a condition for the event-triggered measurement reporting is still fulfilled.

[0206] In some example embodiments, the TTT duration is associated with a plurality of reference signals or beams to be measured or associated with a reference signal or a beam to be measured.

[0207] In some example embodiments, the method 1000 further comprises: determining a most recent DL slot, that is no later than an end of the TTT duration, as the CSI reference resource.

[0208] In some example embodiments, the method 1000 further comprises: determining a most recent DL slot with at least a gap before an end of the TTT duration, as the CSI reference resource, wherein the gap comprises at least one symbol or at least one slot determined based on at least one of a capability of the first apparatus, a reporting quantity associated with the event-triggered measurement reporting, or the event-triggered measurement reporting configuration.

[0209] In some example embodiments, the method 1000 further comprises: determining the channel measurement valid for the event evaluation based on at least one measurement made or received no later than the CSI reference resource in a time domain.

[0210] In some example embodiments, the method 1000 further comprises: determining the channel measurement valid for the event evaluation based on at least one reference signal occasion no later than the CSI reference resource in a time domain.

[0211] In some example embodiments, the at least one reference signal occasion comprises a certain number of most recent reference signal occasions no later than the CSI reference resource in the time domain.

[0212] In some example embodiments, the method 1000 further comprises: obtaining an indication associated with the certain number from a configuration of the event-triggered measurement reporting.

[0213] In some example embodiments, the method 1000 further comprises: determining the channel measurement valid for the event evaluation based on at least one measurement until a time period after the CSI reference resource in a time domain and no later than the end of the TTT duration.

[0214] In some example embodiments, the method 1000 further comprises: determining the channel measurement valid for the event evaluation based on at least one reference signal occasion until a time period after the CSI reference resource in a time domain and no later than the end of the TTT duration.

[0215] In some example embodiments, the time period is based on at least one of acapability of the first apparatus, a reporting quantity associated with the event-triggered measurement reporting, or a configuration from the second apparatus.

[0216] In some example embodiments, the method 1000 further comprises: in accordance with a determination that a periodic reporting is configured for the event-triggered measurement reporting, determining the CSI reference resource for the first periodic reporting or first reporting instance of the event-triggered measurement reporting based at least on the TTT duration.

[0217] In some example embodiments, the message comprises a radio resource control, RRC, configuration message or an RRC reconfiguration message, or an activation command associated with a reference signal transmission.

[0218] In some example embodiments, the first apparatus comprises a terminal device and the second apparatus comprises a network device.

[0219] FIG. 11 shows a flowchart of an example method 1100 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 1100 will be described from the perspective of the first apparatus 110 in FIG. 1.

[0220] At block 1110, the first apparatus 110 receives, from a second apparatus, a message at least comprising configuration information associated with a TTT.

[0221] At block 1120, the first apparatus 110 determines, based on the configuration information, a TTT duration prior to a slot associated with an event-triggered measurement reporting, wherein the TTT duration is associated with at least one reference signal or at least one beam to be measured for an event-triggered measurement reporting.

[0222] At block 1130, the first apparatus 110 determines a channel measurement valid for an event evaluation or reporting for the event-triggered measurement reporting based at least on the TTT duration.

[0223] At block 1140, the first apparatus 110 performs the event evaluation for the event-triggered measurement using the channel measurement.

[0224] In some example embodiments, the TTT duration overlaps with the at least one DL slot and prior to a slot associated with the event -triggered measurement reporting.

[0225] In some example embodiments, the TTT duration comprises a slot or a symbol inthe slot where a TTT timer is expected to expire and a condition for the event-triggered measurement reporting is still fulfilled.

[0226] In some example embodiments, the TTT duration is associated with a plurality of reference signals or beams to be measured or associated with a reference signal or a beam to be measured.

[0227] In some example embodiments, the TTT duration corresponds to the latest TTT in a plurality of TTTs associated with the plurality of reference signals or beams to be measured, or corresponds to the latest TTT in a plurality of TTTs associated with the reference signal or the beam to be measured.

[0228] In some example embodiments, the slot is an available uplink slot after the TTT duration for carrying an uplink signal for requesting uplink resources for the event-triggered measurement reporting or carrying the event-triggered measurement reporting.

[0229] In some example embodiments, the slot is the first uplink slot carrying an uplink control or data transmission after the latest TTT duration in the at least one TTT duration.

[0230] In some example embodiments, the method 1100 further comprises: determining the channel measurement valid for the event evaluation or reporting based on at least one measurement no later than the end of the TTT duration.

[0231] In some example embodiments, the method 1100 further comprises: determining the channel measurement valid for the event evaluation or reporting based on at least one reference signal occasion no later than the end of the TTT duration.

[0232] In some example embodiments, the method 1100 further comprises: in accordance with a determination that a periodic reporting is configured for the event-triggered measurement reporting, determining a channel measurement valid for the first periodic reporting or first reporting instance of the event-triggered measurement reporting based at least on the TTT duration

[0233] In some example embodiments, the message comprises a radio resource control, RRC, configuration message or an RRC reconfiguration message, or an activation command associated with a reference signal transmission.

[0234] In some example embodiments, the first apparatus comprises a terminal device and the second apparatus comprises a network device.

[0235] In some example embodiments, a first apparatus capable of performing any of the method 800 (for example, the first apparatus 110 in FIG. 1) may comprise means for performing the respective operations of the method 800. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the first apparatus 110 in FIG. 1.

[0236] In some example embodiments, the first apparatus comprises means for receiving, from a second apparatus, a message at least comprising configuration information associated with a TTT; means for determining, based on the configuration information, a TTT duration prior to a slot associated with an event-triggered measurement reporting, wherein the TTT duration is associated with a reference signal or a beam to be measured for an event-triggered measurement reporting; means for determining a CSI reference resource for the event -triggered measurement reporting based at least on the TTT duration.

[0237] In some example embodiments, the TTT duration overlaps with at least one DL slot.

[0238] In some example embodiments, the TTT duration comprises a slot or a symbol in the slot where a TTT timer is expected to expire and a condition for the event-triggered measurement reporting is still fulfilled.

[0239] In some example embodiments, the TTT duration corresponds to the latest TTT in a plurality of TTTs.

[0240] In some example embodiments, the first apparatus further comprises: means for starting the TTT timer of the first TTT in the plurality of TTTs after processing the event-triggered measurement reporting configuration or after a processing of an activation command for activating the event-triggered measurement reporting configuration or after a processing of an activation command for activating at least an RS or at least a measurement on at least an RS to be measured for the event-triggered measurement reporting.

[0241] In some example embodiments, the first apparatus further comprises: means for receiving, via the message, an indication of one or more occasions of the reference signal or the beam to be measured; and means for starting, from the first symbol of the one or more occasions, the TTT timer of the first TTT in the plurality of TTTs.

[0242] In some example embodiments, the first apparatus further comprises: means for restarting the TTT timer of a second TTT subsequent to the first TTT upon at least one of an expiry of the first TTT, or an expiry of all first TTTs associated with all reference signals or beams to be measured for the event-triggered measurement reporting.

[0243] In some example embodiments, the slot is an available uplink slot after the TTT duration for carrying an uplink signal for requesting uplink resources for the event-triggered measurement reporting or carrying the event-triggered measurement reporting.

[0244] In some example embodiments, the slot is a first uplink slot carrying an uplink control or data transmission after the latest TTT duration in the at least one TTT duration.

[0245] In some example embodiments, the first apparatus further comprises: means for determining the most recent DL slot, that is no later than an end of the TTT duration, as the CSI reference resource.

[0246] In some example embodiments, the first apparatus further comprises: means for determining the most recent DL slot with at least a gap before the end of the TTT duration, as the CSI reference resource.

[0247] In some example embodiments, the gap comprises at least one symbol or at least one slot.

[0248] In some example embodiments, the first apparatus further comprises: means for determining the gap based on at least one of a capability of the first apparatus or a reporting quantity associated with the event-triggered measurement reporting.

[0249] In some example embodiments, the first apparatus further comprises: means for obtaining a configuration of the gap from an event-triggered measurement reporting configuration.

[0250] In some example embodiments, the first apparatus further comprises: means for in accordance with a determination that a periodic reporting is configured for the event-triggered measurement reporting, determining the CSI reference resource for the first periodic reporting or first reporting instance of the event-triggered measurement reporting based at least on the TTT duration.

[0251] In some example embodiments, the message comprises a radio resource control, RRC, configuration message, or an RRC reconfiguration message, or an activationcommand associated with a reference signal transmission.

[0252] In some example embodiments, the first apparatus comprises a terminal device and the second apparatus comprises a network device.

[0253] In some example embodiments, a first apparatus capable of performing any of the method 900 (for example, the first apparatus 110 in FIG. 1) may comprise means for performing the respective operations of the method 900. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the first apparatus 110 in FIG. 1.

[0254] In some example embodiments, the first apparatus comprises means for receiving, from a second apparatus, a message at least comprising configuration information associated with a TTT; means for determining, based on the configuration information, a TTT duration prior to a slot associated with an event-triggered measurement reporting, wherein the TTT duration is associated with a plurality of reference signals or beams to be measured or is per event type or reporting configuration associated with the event-triggered measurement reporting; and means for determining a channel State Information, CSI, reference resource based at least on the TTT duration.

[0255] In some example embodiments, the TTT duration overlaps with at least one DL slot.

[0256] In some example embodiments, the TTT duration comprises a slot or a symbol in the slot where a TTT timer is expected to expire and a condition for the event-triggered measurement reporting is still fulfilled.

[0257] In some example embodiments, the TTT duration corresponds to the latest TTT in a plurality of TTTs.

[0258] In some example embodiments, the first apparatus further comprises: means for starting the TTT timer of the first TTT in the plurality of TTTs after processing the event-triggered measurement reporting configuration or after a processing of an activation command for activating the event-triggered measurement reporting configuration or after a processing of an activation command for activating at least an RS or at least a measurement on at least an RS to be measured for the event-triggered measurement reporting.

[0259] In some example embodiments, the first apparatus further comprises: means for receiving, via the message, an indication of one or more occasions of the reference signal or the beam to be measured; and means for starting, from the first symbol of the one or more occasions, the TTT timer of the first TTT in the plurality of TTTs.

[0260] In some example embodiments, the first apparatus further comprises: means for restarting the TTT timer of a second TTT subsequent to the first TTT upon at least one of: an expiry of the first TTT, or an expiry of all first TTTs associated with all reference signals or beams to be measured for the event-triggered measurement reporting.

[0261] In some example embodiments, the slot is an available uplink slot after the TTT duration for carrying an uplink signal for requesting uplink resources for the event-triggered measurement reporting or carrying the event-triggered measurement reporting.

[0262] In some example embodiments, the slot is the first uplink slot carrying an uplink control or data transmission after the latest TTT duration in the at least one TTT duration.

[0263] In some example embodiments, the first apparatus further comprises: means for determining a most recent DL slot, that is no later than an end of the TTT duration, as the CSI reference resource.

[0264] In some example embodiments, the first apparatus further comprises: means for determining a most recent DL slot with at least a gap before the end of the TTT duration, as the CSI reference resource.

[0265] In some example embodiments, the gap comprises at least one symbol or at least one slot.

[0266] In some example embodiments, the first apparatus further comprises: means for determining the gap based on at least one of a capability of the first apparatus or a reporting quantity associated with the event-triggered measurement reporting.

[0267] In some example embodiments, the first apparatus further comprises: means for obtaining a configuration of the gap from an event-triggered measurement reporting configuration.

[0268] In some example embodiments, the first apparatus further comprises: means for in accordance with a determination that a periodic reporting is configured for the event-triggered measurement reporting, determining the CSI reference resource for the firstperiodic reporting or first reporting instance of the event-triggered measurement reporting based at least on the TTT duration.

[0269] In some example embodiments, the message comprises a radio resource control, RRC, configuration message or an RRC reconfiguration message, or an activation command associated with a reference signal transmission.

[0270] In some example embodiments, the first apparatus comprises a terminal device and the second apparatus comprises a network device.

[0271] In some example embodiments, a first apparatus capable of performing any of the method 1000 (for example, the first apparatus 110 in FIG. 1) may comprise means for performing the respective operations of the method 1000. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the first apparatus 110 in FIG. 1.

[0272] In some example embodiments, the first apparatus comprises means for receiving, from a second apparatus, a message at least comprising configuration information associated with a TTT; means for determining a CSI reference resource for an event-triggered measurement reporting based at least on a TTT duration that is determined based on the configuration information and at least one DL slot; and means for determining a channel measurement valid for an event evaluation or for reporting for the event -triggered measurement reporting based at least on the CSI reference resource; and means for performing the event evaluation or reporting for the event-triggered measurement based on the channel measurement.

[0273] In some example embodiments, the TTT duration overlaps with the at least one downlink, DL, slot and prior to a slot associated with the event-triggered measurement reporting.

[0274] In some example embodiments, the slot is an available uplink slot after the TTT duration for carrying an uplink signal for requesting uplink resources for the event-triggered measurement reporting or carrying the event-triggered measurement reporting.

[0275] In some example embodiments, the slot is a first uplink slot carrying an uplink control or data transmission after the latest TTT duration in the at least one TTT duration.

[0276] In some example embodiments, the TTT duration comprises a slot or a symbol in the slot where a TTT timer is expected to expire and a condition for the event-triggered measurement reporting is still fulfilled.

[0277] In some example embodiments, the TTT duration is associated with a plurality of reference signals or beams to be measured or associated with a reference signal or a beam to be measured.

[0278] In some example embodiments, the first apparatus further comprises: means for determining a most recent DL slot, that is no later than an end of the TTT duration, as the CSI reference resource.

[0279] In some example embodiments, the first apparatus further comprises: means for determining a most recent DL slot with at least a gap before an end of the TTT duration, as the CSI reference resource , wherein the gap comprises at least one symbol or at least one slot determined based on at least one of a capability of the first apparatus, a reporting quantity associated with the event -triggered measurement reporting, or the event -triggered measurement reporting configuration.

[0280] In some example embodiments, the first apparatus further comprises: means for determining the channel measurement valid for the event evaluation based on at least one measurement made or received no later than the CSI reference resource in a time domain.

[0281] In some example embodiments, the first apparatus further comprises: means for determining the channel measurement valid for the event evaluation based on at least one reference signal occasion no later than the CSI reference resource in a time domain.

[0282] In some example embodiments, the at least one reference signal occasion comprises a certain number of most recent reference signal occasions no later than the CSI reference resource in the time domain.

[0283] In some example embodiments, the first apparatus further comprises: means for obtaining an indication associated with the certain number from a configuration of the event-triggered measurement reporting.

[0284] In some example embodiments, the first apparatus further comprises: means for determining the channel measurement valid for the event evaluation based on at least one measurement until a time period after the CSI reference resource in a time domain and nolater than the end of the TTT duration.

[0285] In some example embodiments, the first apparatus further comprises: means for determining the channel measurement valid for the event evaluation based on at least one reference signal occasion until a time period after the CSI reference resource in a time domain and no later than the end of the TTT duration.

[0286] In some example embodiments, the time period is based on at least one of a capability of the first apparatus, a reporting quantity associated with the event-triggered measurement reporting, or a configuration from the second apparatus.

[0287] In some example embodiments, the first apparatus further comprises: means for in accordance with a determination that a periodic reporting is configured for the event-triggered measurement reporting, determining the CSI reference resource for the first periodic reporting or first reporting instance of the event-triggered measurement reporting based at least on the TTT duration.

[0288] In some example embodiments, the message comprises a radio resource control, RRC, configuration message or an RRC reconfiguration message, or an activation command associated with a reference signal transmission.

[0289] In some example embodiments, the first apparatus comprises a terminal device and the second apparatus comprises a network device.

[0290] In some example embodiments, a first apparatus capable of performing any of the method 1100 (for example, the first apparatus 110 in FIG. 1) may comprise means for performing the respective operations of the method 1100. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the first apparatus 110 in FIG. 1.

[0291] In some example embodiments, the first apparatus comprises means for receiving, from a second apparatus, a message at least comprising configuration information associated with a TTT; means for determining, based on the configuration information, a TTT duration prior to a slot associated with an event-triggered measurement reporting, wherein the TTT duration is associated with at least one reference signal or at least one beam to be measured for an event-triggered measurement reporting; means for determining a channel measurement valid for an event evaluation or reporting for theevent-triggered measurement reporting based at least on the TTT duration; and means for performing the event evaluation for the event-triggered measurement using the channel measurement.

[0292] In some example embodiments, the TTT duration overlaps with the at least one DL slot and prior to a slot associated with the event -triggered measurement reporting.

[0293] In some example embodiments, the TTT duration comprises a slot or a symbol in the slot where a TTT timer is expected to expire and a condition for the event-triggered measurement reporting is still fulfilled.

[0294] In some example embodiments, the TTT duration is associated with a plurality of reference signals or beams to be measured or associated with a reference signal or a beam to be measured.

[0295] In some example embodiments, the TTT duration corresponds to the latest TTT in a plurality of TTTs associated with the plurality of reference signals or beams to be measured, or corresponds to the latest TTT in a plurality of TTTs associated with the reference signal or the beam to be measured.

[0296] In some example embodiments, the slot is an available uplink slot after the TTT duration for carrying an uplink signal for requesting uplink resources for the event-triggered measurement reporting or carrying the event-triggered measurement reporting.

[0297] In some example embodiments, the slot is the first uplink slot carrying an uplink control or data transmission after the latest TTT duration in the at least one TTT duration.

[0298] In some example embodiments, the first apparatus further comprises: means for determining the channel measurement valid for the event evaluation or reporting based on at least one measurement no later than the end of the TTT duration.

[0299] In some example embodiments, the first apparatus further comprises: means for determining the channel measurement valid for the event evaluation or reporting based on at least one reference signal occasion no later than the end of the TTT duration.

[0300] In some example embodiments, the first apparatus further comprises: means for in accordance with a determination that a periodic reporting is configured for the event-triggered measurement reporting, determining a channel measurement valid for the first periodic reporting or first reporting instance of the event-triggered measurement reportingbased at least on the TTT duration

[0301] In some example embodiments, the message comprises a radio resource control, RRC, configuration message or an RRC reconfiguration message, or an activation command associated with a reference signal transmission.

[0302] In some example embodiments, the first apparatus comprises a terminal device and the second apparatus comprises a network device.

[0303] FIG. 12 is a simplified block diagram of a device 1200 that is suitable for implementing example embodiments of the present disclosure. The device 1200 may be provided to implement a communication device, for example, the first apparatus 110 or the second apparatus 120 as shown in FIG. 1. As shown, the device 1200 includes one or more processors 1210, one or more memories 1220 coupled to the processor 1210, and one or more communication modules 1240 coupled to the processor 1210.

[0304] The communication module 1240 is for bidirectional communications. The communication module 1240 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interfaces may represent any interface that is necessary for communication with other network elements. In some example embodiments, the communication module 1240 may include at least one antenna.

[0305] The processor 1210 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 1200 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

[0306] The memory 1220 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 1224, an electrically programmable read only memory (EPROM), a flash memory, a hard disk, a compact disc (CD), a digital video disk (DVD), an optical disk, a laser disk, and other magnetic storage and / or optical storage. Examples of the volatile memories include, but are not limited to, a random-access memory (RAM) 1222 and other volatile memories that will not last in the power-downduration.

[0307] A computer program 1230 includes computer executable instructions that are executed by the associated processor 1210. The instructions of the program 1230 may include instructions for performing operations / acts of some example embodiments of the present disclosure. The program 1230 may be stored in the memory, e.g., the ROM 1224. The processor 1210 may perform any suitable actions and processing by loading the program 1230 into the RAM 1222.

[0308] The example embodiments of the present disclosure may be implemented by means of the program 1230 so that the device 1200 may perform any process of the disclosure as discussed with reference to FIG. 2 to FIG. 7. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0309] In some example embodiments, the program 1230 may be tangibly contained in a computer readable medium which may be included in the device 1200 (such as in the memory 1220) or other storage devices that are accessible by the device 1200. The device 1200 may load the program 1230 from the computer readable medium to the RAM 1222 for execution. In some example embodiments, the computer readable medium may include any types of non-transitory storage medium, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0310] FIG. 13 shows an example of the computer readable medium 1300 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 1300 has the program 1230 stored thereon.

[0311] Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, and other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. Although various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware,software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0312] Some example embodiments of the present disclosure also provide at least one computer program product tangibly stored on a computer readable medium, such as a non-transitory computer readable medium. The computer program product includes computerexecutable instructions, such as those included in program modules, being executed in a device on a target physical or virtual processor, to carry out any of the methods as described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

[0313] Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. The program code may be provided to a processor or controller of a general-purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program code, when executed by the processor or controller, cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

[0314] In the context of the present disclosure, the computer program code or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

[0315] The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random-accessmemory (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.

[0316] Further, although operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, although several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Unless explicitly stated, certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated, various features that are described in the context of a single embodiment may also be implemented in a plurality of embodiments separately or in any suitable sub-combination.

[0317] Although the present disclosure has been described in languages specific to structural features and / or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

WHAT IS CLAIMED IS:

1. A first apparatus comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to:receive, from a second apparatus, a message at least comprising configuration information associated with a time to trigger, TTT;determine, based on the configuration information, a TTT duration prior to a slot associated with an event-triggered measurement reporting, wherein the TTT duration is associated with a reference signal or a beam to be measured for an event-triggered measurement reporting; anddetermine a channel state information, CSI, reference resource for the event-triggered measurement reporting based at least on the TTT duration.

2. The first apparatus of claim 1, wherein the TTT duration overlaps with at least one downlink, DL, slot.

3. The first apparatus of claim 1 or 2, wherein the TTT duration comprises a slot or a symbol in the slot where a TTT timer is expected to expire and a condition for the event-triggered measurement reporting is still fulfilled.

4. The first apparatus of any of claims 1-3, wherein the TTT duration corresponds to the latest TTT in a plurality of TTTs.

5. The first apparatus of claim 4, wherein the first apparatus is further caused to: start the TTT timer of the first TTT in the plurality of TTTs after processing the event-triggered measurement reporting configuration or after a processing of an activation command for activating the event-triggered measurement reporting configuration or after a processing of an activation command for activating at least an RS or at least a measurement on at least an RS to be measured for the event-triggered measurement reporting.

6. The first apparatus of claim 4, wherein the first apparatus is further caused to: receive, via the message, an indication of one or more occasions of the reference signal or the beam to be measured; andstart, from the first symbol of the one or more occasions, the TTT timer of the first TTT in the plurality of TTTs.

7. The first apparatus of claim 5 or 6, wherein the first apparatus is caused to: restart the TTT timer of a second TTT subsequent to the first TTT upon at least one of: an expiry of the first TTT, oran expiry of all first TTTs associated with all reference signals or beams to be measured for the event-triggered measurement reporting.

8. The first apparatus of any of claims 1-7, wherein the slot is an available uplink slot after the TTT duration for carrying an uplink signal for requesting uplink resources for the event-triggered measurement reporting or carrying the event-triggered measurement reporting.

9. The first apparatus of any of claims 1-7, wherein the slot is a first uplink slot carrying an uplink control or data transmission after the latest TTT duration in the at least one TTT duration.

10. The first apparatus of any of claims 1-9, wherein the first apparatus is caused to: determine the most recent DL slot, that is no later than an end of the TTT duration, as the CSI reference resource.

11. The first apparatus of any of claims 1-10, wherein the first apparatus is caused to: determine the most recent DL slot with at least a gap before the end of the TTT duration, as the CSI reference resource.

12. The first apparatus of claim 11, wherein the gap comprises at least one symbol or at least one slot.

13. The first apparatus of claim 11 or 12, wherein the first apparatus is caused to: determine the gap based on at least one of a capability of the first apparatus or a reporting quantity associated with the event-triggered measurement reporting.

14. The first apparatus of claim 11 or 12, wherein the first apparatus is caused to: obtain a configuration of the gap from an event-triggered measurement reporting configuration.

15. The first apparatus of any of claims 1-14, wherein the first apparatus is caused to: in accordance with a determination that a periodic reporting is configured for the event-triggered measurement reporting, determine the CSI reference resource for the first periodic reporting or first reporting instance of the event-triggered measurement reporting based at least on the TTT duration.

16. The first apparatus of any of claims 1-15, wherein the message comprises a radio resource control, RRC, configuration message, or an RRC reconfiguration message, or an activation command associated with a reference signal transmission.

17. The first apparatus of any of claims 1-16, wherein the first apparatus comprises a terminal device and the second apparatus comprises a network device.

18. A method comprising:receiving, by a first apparatus from a second apparatus, a message at least comprising configuration information associated with a time to trigger, TTT;determining, based on the configuration information, a TTT duration prior to a slot associated with an event-triggered measurement reporting, wherein the TTT duration is associated with a reference signal or a beam to be measured for an event-triggered measurement reporting; anddetermining a channel state information, CSI, reference resource for the event-triggered measurement reporting based at least on the TTT duration.

19. A first apparatus comprising:means for receiving, from a second apparatus, a message at least comprising configuration information associated with a time to trigger, TTT;means for determining, based on the configuration information, a TTT duration prior to a slot associated with an event-triggered measurement reporting, wherein the TTT duration is associated with a reference signal or a beam to be measured for an event-triggered measurementreporting; andmeans for determining a channel state information, CSI, reference resource for the event-triggered measurement reporting based at least on the TTT duration.

20. A computer readable medium comprising instructions stored thereon for causing an apparatus at least to perform the method of claim 18.

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