Event-triggered reporting

Abstract

Example embodiments of the present disclosure are directed to a solution of event- triggered reporting. A method comprises receiving, from a second apparatus, an event- triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; determining a plurality of candidate cells, at least one event in the list of events being detected for each of the plurality of candidate cells; determining at least one candidate cell from the plurality of candidate cells to perform preparation of cell switch; and performing the cell switch preparation on at least one candidate cell.

Description

EVENT-TRIGGERED REPORTINGFIELDS

[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 event-triggered reporting.BACKGROUND

[0002] In order to ensure the communication continuousness in the wireless communication system, multiple technologies are proposed, such as cell switch. During the cell switch, the terminal device may switch among different cells. Further, technology of layer 1 / layer 2 (L1 / L2) triggered mobility (LTM) may be used for enabling the cell switch. LTM is a procedure in which the next generation node B (gNB) receives layer 1 (LI) and / or layer 3 (L3) measurement report(s) from a UE, and thus the gNB changes user equipment (UE)serving cell by a cell switch command signalled via a medium access control control element (MAC CE). The cell switch command indicates an LTM candidate configuration that the gNB previously prepared and provided to the UE through radio resource control (RRC) signalling. Then the UE switches to the target configuration according to the cell switch command. The LTM procedure may be used to reduce the mobility latency.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 to: receive, from a second apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; based on at least one event in the list of events being detected for a candidate cell of the list of candidate cells, pre-process a candidate cell configuration of the candidate cell; receive, from the second apparatus, a switch command of the candidate cell transmitted by the second apparatus in response to receiving a measurement report of the candidate cell; and determine a cell switch delay based on at least one of the following: whether the candidate icell configuration of the candidate cell has been pre-processed, a starting time point for pre-processing the candidate cell configuration, or an ending time point for pre-processing the candidate cell configuration.

[0004] In a second aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus to: transmit, to a first apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; receive, from the first apparatus, a measurement report transmitted by the first apparatus in response to at least one event in the list of events being detected for a candidate cell of the list of candidate cells; transmit, to the first apparatus, a switch command of the candidate cell in response to receiving the measurement report; and determine a cell switch delay based on at least one of the following: whether a candidate cell configuration of the candidate cell has been pre-processed by the first apparatus, a starting time point for pre-processing the candidate cell configuration, or an ending time point for preprocessing the candidate cell configuration.

[0005] In a third aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus to: receive, from a second apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; based on at least one event in the list of events being detected for a candidate cell of the list of candidate cells, perform preparation comprising time / frequency synchronization for the candidate cell; receive, from the second apparatus, a switch command of the candidate cell transmitted by the second apparatus in response to receiving a measurement report of the candidate cell; and determine a switch-related delay based on at least one of the following: whether the time / frequency synchronization for the candidate cell has been performed, a starting time point for performing the time / frequency synchronization for the candidate cell, or an ending time point for performing the time / frequency synchronization for the candidate cell.

[0006] In a fourth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises at least one processor; and at least one memory storinginstructions that, when executed by the at least one processor, cause the second apparatus to: transmit, to a first apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; receive, from the first apparatus, a measurement report transmitted by the first apparatus in response to at least one event in the list of events being detected for a candidate cell of the list of candidate cells; transmit, to the first apparatus, a switch command of the candidate cell in response to receiving the measurement report; and determine a switch- related delay based on at least one of the following: whether preparation comprising time / frequency synchronization for the candidate cell has been performed by the first apparatus, a starting time point for performing the time / frequency synchronization for the candidate cell, or an ending time point for performing the time / frequency synchronization for the candidate cell.

[0007] In a fifth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus to: receive, from a second apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; based on at least one event in the list of events being detected for a candidate cell of the list of candidate cells, perform preparation comprising user equipment (UE)-based timing advance (TA) estimation for the candidate cell; receive, from the second apparatus, a switch command of the candidate cell transmitted by the second apparatus in response to receiving a measurement report of the candidate cell; and determine a cell switch delay based on at least one of the following: whether the UE-based TA estimation for the candidate cell has been performed, a starting time point for performing the UE-based TA estimation for the candidate cell, or an ending time point for performing the UE-based TA estimation for the candidate cell.

[0008] In a sixth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus to: transmit, to a first apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; receive, from the first apparatus, a measurement report transmitted by the first apparatus inresponse to at least one event in the list of events being detected for a candidate cell of the list of candidate cells; transmit, to the first apparatus, a switch command of the candidate cell in response to receiving the measurement report; and determine a cell switch delay based on at least one of the following: whether preparation comprising user equipment (UE)-based timing advance (TA) estimation for the candidate cell has been performed by the first apparatus, a starting time point for performing the UE-based TA estimation for the candidate cell, or an ending time point for performing the UE-based TA estimation for the candidate cell.

[0009] In a seventh aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus to: receive, from a second apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; determine a plurality of candidate cells, at least one event in the list of events being detected for each of the plurality of candidate cells; determine at least one candidate cell from the plurality of candidate cells to perform preparation of cell switch based on at least one of the following: a plurality of signal qualities of the plurality of candidate cells, a plurality of time points at which the plurality of candidate cell fulfill respective reporting conditions, a plurality of events detected on the plurality of candidate cell, a priority order of the plurality of candidate cells, a plurality of switch types of the plurality of candidate cells, a plurality of switch states of the plurality of candidate cells, or a plurality of cell identities of the plurality of candidate cells; and perform the cell switch preparation on at least one candidate cell.

[0010] In an eighth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus to: generate, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells, wherein the LTM-based configuration comprises at least one of the following: an indication for enabling or disabling performing preparation of cell switch at the first apparatus, an event priority order used by the first apparatus to determine at least one candidate cell to perform the preparation of cell switch from a plurality of candidate cells, a candidate cell priorityorder used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, a switch type priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, or at least one rule used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells; and transmit the event-triggered reporting configuration to a first apparatus.

[0011] In a ninth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus to: receive, from a second apparatus, a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)- based configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; perform, based on the LTM-based configuration, measurements on the list of candidate cells; determine, based on measurement results of the measurements, at least one event being detected for a candidate cell of the list of candidate cells; suspend a transmission of a layer 1 (LI) measurement report triggered by the at least one event until a reporting criterion is fulfilled, wherein the reporting criterion is determined to be fulfilled at least based on a preparation of cell switch has been performed.

[0012] In a tenth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus to: transmit, to a first apparatus, a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration indicating and a list of candidate cells and a list of events configured for the list of candidate cells; and receive, from the first apparatus, a layer 1 (LI) measurement report triggered by at least one event in the list of events being detected for a candidate cell of the list of candidate cells, wherein the LI measurement report is transmitted by the first apparatus in response to a reporting criterion being fulfilled, wherein the reporting criterion is determined to be fulfilled at least based on a preparation of cell switch has been performed.

[0013] In an eleventh aspect of the present disclosure, there is provided a method. The method comprises: receiving, from a second apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; based on at least one event in the list of events being detected for acandidate cell of the list of candidate cells, pre-processing a candidate cell configuration of the candidate cell; receiving, from the second apparatus, a switch command of the candidate cell transmitted by the second apparatus in response to receiving a measurement report of the candidate cell; and determining a cell switch delay based on at least one of the following: whether the candidate cell configuration of the candidate cell has been pre- processed, a starting time point for pre-processing the candidate cell configuration, or an ending time point for pre-processing the candidate cell configuration.

[0014] In a twelfth aspect of the present disclosure, there is provided a method. The method comprises: transmitting, to a first apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; receiving, from the first apparatus, a measurement report transmitted by the first apparatus in response to at least one event in the list of events being detected for a candidate cell of the list of candidate cells; transmitting, to the first apparatus, a switch command of the candidate cell in response to receiving the measurement report; and determining a cell switch delay based on at least one of the following: whether a candidate cell configuration of the candidate cell has been pre-processed by the first apparatus, a starting time point for pre-processing the candidate cell configuration, or an ending time point for pre-processing the candidate cell configuration.

[0015] In a thirteenth aspect of the present disclosure, there is provided a method. The method comprises: receiving, from a second apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; based on at least one event in the list of events being detected for a candidate cell of the list of candidate cells, performing preparation comprising time / frequency synchronization for the candidate cell; receiving, from the second apparatus, a switch command of the candidate cell transmitted by the second apparatus in response to receiving a measurement report of the candidate cell; and determining a switch-related delay based on at least one of the following: whether the time / frequency synchronization for the candidate cell has been performed, a starting time point for performing the time / frequency synchronization for the candidate cell, or an ending time point for performing the time / frequency synchronization for the candidate cell.

[0016] In a fourteenth aspect of the present disclosure, there is provided a method. The method comprises: transmitting, to a first apparatus, an event-triggered reportingconfiguration indicating a list of candidate cells and a list of events configured for the list of candidate cells; receiving, from the first apparatus, a measurement report transmitted by the first apparatus in response to at least one event in the list of events being detected for a candidate cell of the list of candidate cells; transmitting, to the first apparatus, a switch command of the candidate cell in response to receiving the measurement report; and determining a switch-related delay based on at least one of the following: whether preparation comprising time / frequency synchronization for the candidate cell has been performed by the first apparatus, a starting time point for performing the time / frequency synchronization for the candidate cell, or an ending time point for performing the time / frequency synchronization for the candidate cell.

[0017] In a fifteenth aspect of the present disclosure, there is provided a method. The method comprises: receiving, from a second apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; based on at least one event in the list of events being detected for a candidate cell of the list of candidate cells, performing preparation comprising user equipment (UE)-based timing advance (TA) estimation for the candidate cell; receiving, from the second apparatus, a switch command of the candidate cell transmitted by the second apparatus in response to receiving a measurement report of the candidate cell; and determining a cell switch delay based on at least one of the following: whether the UE- based TA estimation for the candidate cell has been performed, a starting time point for performing the UE -based TA estimation for the candidate cell, or an ending time point for performing the UE-based TA estimation for the candidate cell.

[0018] In a sixteenth aspect of the present disclosure, there is provided a method. The method comprises: transmitting, to a first apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; receiving, from the first apparatus, a measurement report transmitted by the first apparatus in response to at least one event in the list of events being detected for a candidate cell of the list of candidate cells; transmitting, to the first apparatus, a switch command of the candidate cell in response to receiving the measurement report; and determining a cell switch delay based on at least one of the following: whether preparation comprising user equipment (UE)-based timing advance (TA) estimation for the candidate cell has been performed by the first apparatus, a starting time point forperforming the UE -based TA estimation for the candidate cell, or an ending time point for performing the UE-based TA estimation for the candidate cell.

[0019] In a seventeenth aspect of the present disclosure, there is provided a method. The method comprises: receiving, from a second apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; determining a plurality of candidate cells, at least one event in the list of events being detected for each of the plurality of candidate cells; determining at least one candidate cell from the plurality of candidate cells to perform preparation of cell switch based on at least one of the following: a plurality of signal qualities of the plurality of candidate cells, a plurality of time points at which the plurality of candidate cell fulfill respective reporting conditions, a plurality of events detected on the plurality of candidate cell, a priority order of the plurality of candidate cells, a plurality of switch types of the plurality of candidate cells, a plurality of switch states of the plurality of candidate cells, or a plurality of cell identities of the plurality of candidate cells; and performing the cell switch preparation on at least one candidate cell.

[0020] In an eighteenth aspect of the present disclosure, there is provided a method. The method comprises: generating, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells, wherein the LTM-based configuration comprises at least one of the following: an indication for enabling or disabling performing preparation of cell switch at the first apparatus, an event priority order used by the first apparatus to determine at least one candidate cell to perform the preparation of cell switch from a plurality of candidate cells, a candidate cell priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, a switch type priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, or at least one rule used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells; and transmitting the event- triggered reporting configuration to a first apparatus.

[0021] In a nineteenth aspect of the present disclosure, there is provided a method. The method comprises: receiving, from a second apparatus, a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; performing, based on the LTM-basedconfiguration, measurements on the list of candidate cells; determining, based on measurement results of the measurements, at least one event being detected for a candidate cell of the list of candidate cells; suspending a transmission of a layer 1 (LI) measurement report triggered by the at least one event until a reporting criterion is fulfilled, wherein the reporting criterion is determined to be fulfilled at least based on a preparation of cell switch has been performed.

[0022] In a twentieth aspect of the present disclosure, there is provided a method. The method comprises: transmitting, to a first apparatus, a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration indicating and a list of candidate cells and a list of events configured for the list of candidate cells; and receiving, from the first apparatus, a layer 1 (LI) measurement report triggered by at least one event in the list of events being detected for a candidate cell of the list of candidate cells, wherein the LI measurement report is transmitted by the first apparatus in response to a reporting criterion being fulfilled, wherein the reporting criterion is determined to be fulfilled at least based on a preparation of cell switch has been performed.

[0023] In a twenty-first aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for receiving, from a second apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; means for, based on at least one event in the list of events being detected for a candidate cell of the list of candidate cells, preprocessing a candidate cell configuration of the candidate cell; means for receiving, from the second apparatus, a switch command of the candidate cell transmitted by the second apparatus in response to receiving a measurement report of the candidate cell; and means for determining a cell switch delay based on at least one of the following: whether the candidate cell configuration of the candidate cell has been pre-processed, a starting time point for pre-processing the candidate cell configuration, or an ending time point for preprocessing the candidate cell configuration.

[0024] In a twenty-second aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises means for transmitting, to a first apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; means for receiving, from the first apparatus, a measurement report transmitted by the first apparatus in response to at leastone event in the list of events being detected for a candidate cell of the list of candidate cells; means for transmitting, to the first apparatus, a switch command of the candidate cell in response to receiving the measurement report; and means for determining a cell switch delay based on at least one of the following: whether a candidate cell configuration of the candidate cell has been pre-processed by the first apparatus, a starting time point for pre-processing the candidate cell configuration, or an ending time point for preprocessing the candidate cell configuration.

[0025] In a twenty-third aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for receiving, from a second apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; means for, based on at least one event in the list of events being detected for a candidate cell of the list of candidate cells, performing preparation comprising time / frequency synchronization for the candidate cell; means for receiving, from the second apparatus, a switch command of the candidate cell transmitted by the second apparatus in response to receiving a measurement report of the candidate cell; and means for determining a switch-related delay based on at least one of the following: whether the time / frequency synchronization for the candidate cell has been performed, a starting time point for performing the time / frequency synchronization for the candidate cell, or an ending time point for performing the time / frequency synchronization for the candidate cell.

[0026] In a twenty-fourth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises means for transmitting, to a first apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; means for receiving, from the first apparatus, a measurement report transmitted by the first apparatus in response to at least one event in the list of events being detected for a candidate cell of the list of candidate cells; means for transmitting, to the first apparatus, a switch command of the candidate cell in response to receiving the measurement report; and means for determining a switch- related delay based on at least one of the following: whether preparation comprising time / frequency synchronization for the candidate cell has been performed by the first apparatus, a starting time point for performing the time / frequency synchronization for the candidate cell, or an ending time point for performing the time / frequencysynchronization for the candidate cell.

[0027] In a twenty-fifth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for receiving, from a second apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; means for, based on at least one event in the list of events being detected for a candidate cell of the list of candidate cells, performing preparation comprising user equipment (UE)-based timing advance (TA) estimation for the candidate cell; means for receiving, from the second apparatus, a switch command of the candidate cell transmitted by the second apparatus in response to receiving a measurement report of the candidate cell; and means for determining a cell switch delay based on at least one of the following: whether the UE -based TA estimation for the candidate cell has been performed, a starting time point for performing the UE- based TA estimation for the candidate cell, or an ending time point for performing the UE-based TA estimation for the candidate cell.

[0028] In a twenty-sixth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises means for transmitting, to a first apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; means for receiving, from the first apparatus, a measurement report transmitted by the first apparatus in response to at least one event in the list of events being detected for a candidate cell of the list of candidate cells; means for transmitting, to the first apparatus, a switch command of the candidate cell in response to receiving the measurement report; and means for determining a cell switch delay based on at least one of the following: whether preparation comprising user equipment (UE)-based timing advance (TA) estimation for the candidate cell has been performed by the first apparatus, a starting time point for performing the UE-based TA estimation for the candidate cell, or an ending time point for performing the UE-based TA estimation for the candidate cell.

[0029] In a twenty-seventh aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for receiving, from a second apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; means for determining a plurality of candidate cells, at least one event in the list of events being detected for each of theplurality of candidate cells; means for determining at least one candidate cell from the plurality of candidate cells to perform preparation of cell switch based on at least one of the following: a plurality of signal qualities of the plurality of candidate cells, a plurality of time points at which the plurality of candidate cell fulfill respective reporting conditions, a plurality of events detected on the plurality of candidate cell, a priority order of the plurality of candidate cells, a plurality of switch types of the plurality of candidate cells, a plurality of switch states of the plurality of candidate cells, or a plurality of cell identities of the plurality of candidate cells; and means for performing the cell switch preparation on at least one candidate cell.

[0030] In a twenty-eighth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises means for generating, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells, wherein the LTM-based configuration comprises at least one of the following: an indication for enabling or disabling performing preparation of cell switch at the first apparatus, an event priority order used by the first apparatus to determine at least one candidate cell to perform the preparation of cell switch from a plurality of candidate cells, a candidate cell priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, a switch type priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, or at least one rule used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells; and means for transmitting the event-triggered reporting configuration to a first apparatus.

[0031] In a twenty -ninth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for receiving, from a second apparatus, a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; means for performing, based on the LTM-based configuration, measurements on the list of candidate cells; means for determining, based on measurement results of the measurements, at least one event being detected for a candidate cell of the list of candidate cells; means for suspending a transmission of a layer 1 (LI) measurement report triggered by the at least one event until a reporting criterion is fulfilled, wherein the reporting criterion is determined to be fulfilled at least based on a preparation of cell switch has been performed.

[0032] In a thirtieth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises means for transmitting, to a first apparatus, a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration indicating and a list of candidate cells and a list of events configured for the list of candidate cells; and means for receiving, from the first apparatus, a layer 1 (LI) measurement report triggered by at least one event in the list of events being detected for a candidate cell of the list of candidate cells, wherein the LI measurement report is transmitted by the first apparatus in response to a reporting criterion being fulfilled, wherein the reporting criterion is determined to be fulfilled at least based on a preparation of cell switch has been performed.

[0033] In a thirty-first 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 any of the eleventh to the twentieth aspect.

[0034] 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

[0035] Some example embodiments will now be described with reference to the accompanying drawings, where:

[0036] FIG. 1 illustrates a signaling flow of LTM;

[0037] FIG. 2 illustrates an example communication environment in which example embodiments of the present disclosure can be implemented;

[0038] FIG. 3 A illustrates an event -triggered reporting procedure in which example embodiments of the present disclosure can be implemented;

[0039] FIG. 3B illustrates a signaling flow of communication in accordance with some embodiments of the present disclosure;

[0040] FIG. 3C illustrates an event-triggered reporting in LTM procedure in which example embodiments of the present disclosure can be implemented;

[0041] FIG. 4 A and FIG. 4B illustrate signaling flows of communication in accordance with some embodiments of the present disclosure;

[0042] FIG. 5 illustrates a flowchart of a method implemented at a first apparatus according to some example embodiments of the present disclosure;

[0043] FIG. 6 illustrates a flowchart of a method implemented at a second apparatus according to some example embodiments of the present disclosure;

[0044] FIG. 7 illustrates a flowchart of a method implemented at a first apparatus according to some example embodiments of the present disclosure;

[0045] FIG. 8 illustrates a flowchart of a method implemented at a second apparatus according to some example embodiments of the present disclosure;

[0046] FIG. 9 illustrates a flowchart of a method implemented at a first apparatus according to some example embodiments of the present disclosure;

[0047] FIG. 10 illustrates a flowchart of a method implemented at a second apparatus according to some example embodiments of the present disclosure;

[0048] FIG. 11 illustrates a flowchart of a method implemented at a first apparatus according to some example embodiments of the present disclosure;

[0049] FIG. 12 illustrates a flowchart of a method implemented at a second apparatus according to some example embodiments of the present disclosure;

[0050] FIG. 13 illustrates a flowchart of a method implemented at a first apparatus according to some example embodiments of the present disclosure;

[0051] FIG. 14 illustrates a flowchart of a method implemented at a second apparatus according to some example embodiments of the present disclosure;

[0052] FIG. 15 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

[0053] FIG. 16 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

[0054] Throughout the drawings, the same or similar reference numerals represent the same or similar element.DETAILED DESCRIPTION

[0055] 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.

[0056] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

[0057] 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.

[0058] It shall be understood that although the terms “first,” “second” and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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 andif 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.

[0064] As used herein, the term “communication network” refers to a network following any suitable communication standards, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G), the second generation (2G), 2.5G, 2.75G, the third generation (3G), the fourth generation (4G), 4.5G, the fifth generation (5G) communication protocols, 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.

[0065] 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.

[0066] The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE), a Subscriber Station (SS), a Portable Subscriber Station, a Mobile Station (MS), or an Access Terminal (AT). The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), USB dongles, smart devices, wireless customerpremises 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.

[0067] As used herein, the term “resource,” “transmission resource,” “resource block,” “physical resource block” (PRB), “uplink resource,” or “downlink resource” may refer to any resource for performing a communication, for example, a communication between a terminal device and a network device, such as a resource in time domain, a resource in frequency domain, a resource in space domain, a resource in code domain, or any other resource enabling a communication, and the like.

[0068] As discussed above, the technology of LTM is used for enabling the cell switch. During the LTM, the gNB receives LI and / or L3 measurement report(s) from a UE, and on their basis the gNB changes UE serving cell by a cell switch command signalled via a MAC CE. The cell switch command indicates an LTM candidate configuration that the gNB previously prepared and provided to the UE through RRC signalling. Then the UE switches to the target configuration according to the cell switch command. The LTMprocedure can be used to reduce the mobility latency.

[0069] Reference is now made to FIG. 1, which illustrates a signaling flow 100 of LTM. In the example of FIG.1, when configured by the network, it is possible to activate TCI states of one or multiple cells that are different from the current serving cell. For instance, one or more of the TCI states of the LTM candidate cells can be activated in advance before any of those cells become the serving cell. This allows the UE to be downlink (DL) synchronized with those cells, thereby facilitating a faster cell switch to one of those cells when cell switch is triggered.

[0070] When configured by the network, it is possible to initiate UL timing advance (TA) acquisition (called early TA) procedure of one or multiple cells that are different from the current serving cells. If the cell has the same NTA as the current serving cells or NTA=0, early TA acquisition procedure is not required. The network may request the UE to perform early TA acquisition of a candidate cell before a cell switch. The early TA acquisition procedure is triggered by physical downlink control channel (PDCCH) order or realized through UE-based TA measurement as configured by radio resource control (RRC).

[0071] In the former case, the gNB to which the candidate cell belongs calculates the TA value based on the RACH preamble transmission on the candidate cell triggered by a PDCCH order and sends it to the gNB to which the serving cell belongs. The serving cell sends the TA value in the LTM cell switch command MAC CE when triggering LTM cell switch. In the latter case, the UE performs TA measurement for the candidate cells after being configured by RRC but the exact time the UE performs TA measurement is up to UE implementation. The UE applies the TA value measured by itself and performs RACH- less LTM upon receiving the cell switch command. The network may also send a TA value in the LTM cell switch command MAC CE without early TA acquisition.

[0072] Depending on the availability of a valid TA value, the UE performs either a random access channel (RACH)-less LTM or RACH-based LTM cell switch. If the TA value is provided in the cell switch command, the UE applies the TA value as instructed by the network. In the case where UE-based TA measurement is configured, but no TA value is provided in the cell switch command, the UE applies the TA value by itself if available. Meanwhile, the UE performs RACH-less LTM cell switch upon receiving the cell switch command. If no valid TA value is available, the UE performs RACH-basedLTM cell switch.

[0073] Regardless of whether the UE is configured for UE-based TA measurement for a certain candidate cell, it will still follow the PDCCH order, which includes requesting a random access procedure towards the candidate cells. This also applies to the candidate cells for which the UE is capable of deriving TA values by itself. Additionally, regardless of whether the UE has already performed a random access procedure towards the candidate cells, it will still follow the UE-based measurement configuration if configured by the network.

[0074] For RACH-less LTM, the UE accesses the target cell using either a configured grant or a dynamic grant. The configured grant is provided in the LTM candidate configuration, and the UE selects the configured grant occasion associated with the beam indicated in the cell switch command. Upon initiation of LTM cell switch to the target cell, the UE starts to monitor PDCCH on the target cell for dynamic scheduling. Before RACH-less LTM procedure completion, the UE shall not trigger random access procedure if it does not have a valid physical uplink control channel (PUCCH) resource for triggered Scheduling Requests (SRs).

[0075] The following principles apply to LTM in Rel-18: security key is maintained upon an LTM cell switch; Subsequent LTM is supported. LTM supports both intra-gNB- distributed unit (DU) and intra-gNB- centralized unit (CU) inter-gNB-DU mobility. LTM supports both intra-frequency and inter-frequency mobility, including mobility to interfrequency cell that is not a current serving cell. LTM is supported only for licensed spectrum. The following scenarios are supported: PCell change in non- carrier aggregation (CA) scenario and non-DC scenario; primary cell (PCell) and secondary cells (SCells) change in CA scenario; Dual connectivity scenario, PCell and master cell group (MCG) SCell(s) change and intra-secondary node (SN) primary secondary cell (PSCell) and secondary cell group (SCG) SCell(s) change without master node (MN) involvement. LTM for simultaneous PCell and PSCell change is not supported. While the UE has stored LTM candidate configurations the UE can also execute any layer 3 (L3) handover command sent by the network.

[0076] TLTM -RRC-processing parameter in the cell switch delay is related to early ASN. 1 decoding and validity check, which is part of the cell switch if UE is not capable of doing this step before the cell switch either always, depending on the number of candidate cells in the LTM configuration or when receiving TCI state activation command or PDCCHorder for a cell.

[0077] TLTM -processing is the time for UE processing, consisting of applying the target cell parameters and L1 / L2 change. The value for this parameter depends on UE capability, but this processing delay is always part of the cell switch.

[0078] Tfirst-Rs and TRS-PTOC are needed when the UE does not have fine time / frequency synchronization to the target cell’s DL. Tfirst-Rs and TRS-PTOC are zero when the target TCI state in the cell switch command is considered active with downlink synchronization, for which many conditions are defined.

[0079] Below agreements have been made on event-triggered reporting. LI LTM measurement event configuration is associated with LI measurement resource configuration provided in LTM configuration via RRC signaling. Further, below agreements on measurement enhancements for LTM have been made:• Event triggered LI measurement should be designed for the following LTM purposes: o- Select the candidate beam / cell to trigger early synchronization. o- 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. o-Event LTM2: Beam of serving cell becomes worse than absolute threshold; o -Event LTM3: Beam of candidate cell becomes amount of offset better than beam of serving cell; o-Event LTM4: Beam of candidate cell becomes better than absolute threshold; o-Event LTM5: Beam of serving cell becomes worse than absolute threshold 1 and Beam of candidate cell becomes better than another absolute threshold2.• Support the beam configuration of both synchronization signal and physical broadcast channel (PBCH) block (SSB) and channel state information (CSI)-reference signal (RS) in LI measurement resource configuration in LTM config. Working assumption: Same RS type should be used for both serving and neighbouring cell for event LTM3 and event LTM5.• RAN2 assumes filtering of the LI measure results is needed. It’s up to RANI whether the specified LI filtering is needed or ok to leave it to UE implementation.• For LTM event evaluation, time to trigger (TTT), hysteresis for entering / leaving, and / or beam specific offset can be applied.

[0080] Regarding L3 measurement report, some reporting delay requirements may be defined. For example, reported reference signal receiving power (RSRP), reference signal receiving quality (RSRQ), and reference signal (RS)-signal to interference plus noise ratio (SINR) measurements contained in event triggered measurement reports shall meet the requirements. Further, the UE shall not send any event triggered measurement reports as long as no reporting criteria is fulfilled.

[0081] The measurement reporting delay is defined as the time between an event that will trigger a measurement report and the point when the UE starts to transmit the measurement report over the air interface. This requirement assumes that the measurement report is not delayed by other RRC signalling on the dedicated control channel (DCCH). This measurement reporting delay excludes a delay uncertainty resulted when inserting the measurement report to the transmission time interval (TTI) of the uplink DCCH. The delay uncertainty is: 2 * TTIDCCH. This measurement reporting delay excludes a delay which caused by no UL resources being available for UE to send the measurement report on.

[0082] The event triggered measurement reporting delay, measured without L3 filtering shall be less than Tidentify intra with index Or T identify intra without index- When L3 filtering is USed an additional delay can be expected. In Evolved Universal Terrestrial Radio Access New Radio (EUTRA-NR) Dual Connection (EN-DC) and New radio-Evolved-universal terrestrial radio access Dual Connectivity (NE-DC) operation, when the UE is configured to perform E-UTRA Sounding reference signal (SRS) carrier-based switching an additional delay can be expected in FR1 if the UE is capable of per-FR gap, or an additional delay can be expected in both FR1 and FR2 if the UE is not capable of per-FR gap.

[0083] A cell is detectable only if at least one SSBs measured from the cell being configured remains detectable during the time period Tidentify intra without index OT T identify intra with index • If a cell which has been detectable at least for the time period Tidentify intra without index or Tidentify intra with index becomes undetectable for a period5 seconds and then the cell becomes detectable again with the same spatial reception parameter andtriggers an event, the event triggered measurement reporting delay shall be less than TSSB measurement period intra provided the timing to that cell has not changed more than ± 3200 / 211Tcwhile the measurement gap has not been available and L3 filtering has not been used, where u is the subcarrier spacing (SCS) configuration. When L3 filtering is used, an additional delay can be expected. In EN-DC and NE-DC operation, when the UE is configured to perform E-UTRA SRS carrier-based switching an additional delay can be expected in FR1 if the UE is capable of per-FR gap, or an additional delay can be expected in both FR1 and FR2 if the UE is not capable of per-FR gap.

[0084] The main goal of LTM is to shorten the interruption caused by handover / cell switch from L3 based handover. Rel-18 introduced multiple ways to do this, but there is still room for improvement. In Rel-18, only periodic, aperiodic and semi-persistent LTM LI measurement reporting was supported. Event-triggered LI measurement reporting is introduced for LTM candidate cells in Rel-19. The purpose of event-triggered report for LTM is to reduce LI measurement reporting overhead on both UE and the network side, and to enable network to configure early DL synchronization or cell switch based on the event-triggered reports. Hence, event triggered report can be considered as the first step towards cell switch. Once the event becomes fulfilled, the UE is allowed event triggered reporting delay of one measurement period before it is required to send the report.

[0085] One of the challenges with the current framework is that after receiving the report, the network may configure other steps of LTM procedure, such as early DL and UL synchronization (i.e., early TCI activation, PDCCH order), before the cell switch. Hence, when the mentioned procedures occur after the event triggered reporting, the time from event condition becoming fulfilled and the time when the cell switch command is sent may become long although the interruption time due to early DL and UL sync, during cell switch is shortened. In other words, the early procedures take long time even if the cell switch time may be reduced, therefore the total time from event triggering to entering the other cell is long. Hence, optimization of the cell switch procedure based on event- triggered LI reporting should be considered.

[0086] According to the embodiments of the present discourse, an event-triggered reporting has been proposed. Especially, the preparation operation may be performed during the cell switch, such that the interruption duration caused by the cell switch may be shortened.Example Environment

[0087] FIG. 2 shows an example communication environment 200 in which example embodiments of the present disclosure can be implemented. The network communication 200 includes a first apparatus 210, a second apparatus 220-1 and optional second apparatuses 220-2 and 220-3. In the following text, the second apparatuses 220-1, 220-2 and 220-3 are collectively referred to as the second apparatuses 220 or individually referred to as the second apparatus 220. Additionally, the second apparatuses 220 may provide one or more coverage areas, also called as cells.

[0088] As illustrated in FIG. 2, the communication environment 200 includes a first cell 240 (also called as source cell or serving cell), a second cell 230-1 and an optional second cell 230-2. In the following text, the second cell 230-1 and the second cell 230-2 are collectively referred to as the second cell 230, and also may be call as candidate cell 230. Further, one of the candidate cells 230 may be selected as a target cell during a cell switch.

[0089] In some embodiments, different cells may be provided by different second apparatus 220. Alternatively, in some embodiments, a same second apparatus 220 may provide more than one cell. For example, in some embodiments, the first cell 240, the second cell 230-1 and the second cell 230-2 may be provided by the second apparatus 220-1. In some other embodiments, the first cell 240, the second cell 230-1 and the second cell 230-2 may be provided by the second apparatus 220-1, the second apparatus 220-2 and the second apparatus 220-3, respectively.

[0090] In addition, in the example of FIG. 2, the first apparatus 210 may move over time. As illustrated in FIG. 2, the first apparatus 210 locates at different positions at different time points (T1 and T2). When moving, the first apparatus 210 may switch among different cells.

[0091] In the example FIG. 2, the first apparatus 220 is serving by the first cell 240. Further, the first apparatus 220 may be configured to measure the second cells 230. Based on the measurement result, the first apparatus 220 may determine a target cell from the second cells and trigger a cell switch to the target cell.

[0092] In the communication environment 200, a link from the first apparatus 210 to the second apparatus 220 is referred to as an uplink, while a link from the second apparatus 220 to the first apparatus 210 is referred to as a downlink. In downlink, the secondapparatus 220 is a transmitting (TX) device (or a transmitter) and the first apparatus 210 is a receiving (RX) device (or a receiver). In uplink, the first apparatus 210 is a TX device (or a transmitter) and the second apparatus 220 is a RX device (or a receiver).

[0093] It is to be understood that the number of devices and their connections shown in FIG. 2 are only for the purpose of illustration without suggesting any limitation. The communication environment 200 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, and one or more additional cells may be deployed in the communication environment 200. It is noted that although illustrated as a network device, the second apparatus 220 may be another device than a network device. Although illustrated as a first apparatus, the first apparatus 210 may be another device than a first apparatus.

[0094] Communications in the communication environment 200 may be implemented according to any proper communication protocol(s), comprising, but not limited to, cellular communication protocols of the first generation (1G), the second generation (2G), the third generation (3G), the fourth generation (4G), the fifth generation (5G), 5.5G, the sixth generation (6G), and the like, 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.Work Principle and Example Signaling for Communication

[0095] For the purposes of discussion, below example embodiments will be discussed with reference to FIG. 2, for example, by using the first apparatus 210 and the second apparatus 220, where the first apparatus 210 may function as a terminal apparatus and the second apparatus 220 may function as a network apparatus. Further, the second apparatus 220 may be serving the first apparatus 210, and the first apparatus 210 is locating in a cellprovided by the second apparatus 220.

[0096] It is to be understood that the operations at the first apparatus 210 and the second apparatus 220 should be coordinated. In other words, the second apparatus 220 and the first apparatus 210 should have a common understand about configurations, parameters and so on. Such a common understand may be implemented by any suitable interactions between the second apparatus 220 and the first apparatus 210 or both the second apparatus 220 and the first apparatus 210 applying the same rule, policy, and / or the like.

[0097] In the following, although some operations are described from a perspective of the first apparatus 210, it is to be understood that the corresponding operations should be performed by the second apparatus 220. Similarly, although some operations are described from a perspective of the second apparatus 220, it is to be understood that the corresponding operations should be performed by the first apparatus 210. Merely for brevity, some of the same or similar contents are omitted here.

[0098] As discussed above, current reporting delay requirements are defined for L3 measurement report. However, since LI event triggered reporting is defined for the first time in Rel-19, there are no reporting delay requirements defined. According to some embodiments of the present disclosure, the LI -based measurement reporting delay mechanism may be introduced.

[0099] Reference is now made to FIG. 3A illustrates an event-triggered reporting procedure 300A in which example embodiments of the present disclosure can be implemented. In the example of FIG. 3 A, the first apparatus 210 shall not send any event triggered measurement reports as long as no reporting criteria is fulfilled. Example processes will be discussed with reference to FIG. 3B, which illustrates a signaling flow of communication in accordance with some embodiments of the present disclosure.

[0100] In operation, the second apparatus 220 transmit (310-1) an LTM-based configuration to the first apparatus 210, and the first apparatus 210 receives (320-2) the LTM-based configuration accordingly. In particular, the LTM-based configuration indicates a list of candidate cells and a list of events configured for the list of candidate cells. It should be noted that in some cases, a same event configuration may be configured to the list of candidate cells. That is, all of the candidate cells are configured with a same list of events. Alternatively, in some cases, the event configuration is configured percandidate cell, i.e., the event configurations for different candidate cells are independently from each other.

[0101] Next, the first apparatus 210 performs (320) measurements on the list of candidate cells based on the LTM-based configuration. In some example embodiments, the measurement may comprise at least one of the following: an LI signal quality associated with a specific event measurement, an LI reference signal receiving power (RSRP) measurement, an LI signal to interference plus noise ratio (SINR) measurement, an LI received signal strength indication (RSSI) measurement, or an LI reference signal receiving quality (RSRQ) measurement.

[0102] Next, the first apparatus 210 determines (330) at least one event being detected for a candidate cell of the list of candidate cells based on measurement results of the measurements. Based on the LI -based measurement reporting delay mechanism, the first apparatus 210 suspend a transmission of an LI measurement report triggered by the at least one event until a reporting criterion is fulfilled. In particular, the reporting criterion is determined to be fulfilled at least based on a preparation of cell switch has been performed.

[0103] In some example embodiments, the preparation of cell switch may comprise at least one of the following: pre-processing a candidate cell configuration of the candidate cell, time / frequency synchronization, user equipment (UE)-based timing advance (TA) estimation, a transmission configuration indicator (TCI) state activation comprising downlink synchronization, a random access channel (RACH)-based TA acquisition, or a physical downlink control channel (PDCCH) ordered RACH preamble transmission.

[0104] In some example embodiments, the first apparatus 210 may perform the preparation of cell switch in response to one of the following: a detection of the at least one of event, a transmission of the LI measurement report triggered by the at least one event, or a reception of acknowledgement of the LI measurement report.

[0105] Optionally, the first apparatus 210 may report its capability -related information on the preparation to the second apparatus 220. Specifically, in some example embodiments, the first apparatus 210 may transmit capability -related information to the second apparatus 220, where the capability-related information indicates that the first apparatus 210 supports the preparation based on detecting the at least one event.

[0106] Optionally, whether the preparation is allowed to performed may be controlled by the second apparatus 220. Specifically, in some example embodiments, the event- triggered reporting configuration transmitted by the second apparatus 220 may comprise an indication for enabling or disabling performing the preparation based on detecting the at least one event.

[0107] As the preparation has been considered as a reporting delay requirement, in some example embodiments, in response to receiving the LI measurement report, the second apparatus 220 may determine that the preparation has been performed by the first apparatus 210.

[0108] In a case that the preparation is pre-processing a candidate cell configuration of the candidate cell, the first apparatus 210 may transmit the LI measurement report to the second apparatus 220 on a condition that the candidate cell configuration has been pre- processed. As a result, the second apparatus 220 may determine that pre-processing the candidate cell configuration has been performed by the first apparatus 210 in response to receiving the LI measurement report.

[0109] In a case that the preparation is a preparation comprising time / frequency synchronization for the candidate cell, the first apparatus 210 may transmit the LI measurement report to the second apparatus on a condition that the time / frequency synchronization has been performed. As a result, the second apparatus 220 may determine that the time / frequency synchronization has been performed has been performed by the first apparatus 210 in response to receiving the LI measurement report.

[0110] In a case that the preparation is a preparation comprising UE-based TA estimation for the candidate cell, the first apparatus 210 may transmit the LI measurement report to the second apparatus on a condition that the UE-based TA estimation has been performed. As a result, the second apparatus 220 may determine that the UE-based TA estimation has been performed has been performed by the first apparatus 210 in response to receiving the LI measurement report.

[0111] According to the above procedures, the preparation procedure may be considered as a factor for controlling the transmission of LI measurement report, which influences the calculation of cell switch delay (DLTM), which is the delay from the end of the last TTI containing the command for cell switch (such as, a MAC CE) until the time the firstapparatus 210 transmits the first UL message on the target cell. As illustrated in FIG. 3B, the second apparatus 220 may determine (360-2) a cell switch delay by assuming the preparation of cell switch has been performed by the first apparatus 210. The first apparatus 210 may also determine (360-1) the cell switch delay accordingly.

[0112] In the following, example embodiments of utilizing the preparation to shorten the cell switch delay will be discussed. It should be noted that below example embodiments may be implemented regardless of whether the LI reporting delay requirement is performed.

[0113] Reference is now made to FIG. 3C, which illustrates an event-triggered reporting in LTM procedure 300C in which example embodiments of the present disclosure can be implemented. As discussed below, according to example embodiments of the present disclosure, the cell switch delay may be shortened.

[0114] Example embodiments where the preparation is pre-processing a configuration of a candidate cell configuration of the candidate cell will be discussed by referring to FIG. 3B.

[0115] As illustrated in FIG. 3B, the second apparatus 220 transmit (310-1) an event- triggered reporting configuration (such as, an LTM-based configuration, or a layer 3 (L3) event-triggered reporting configuration), and the first apparatus 210 receives (320-2) the event-triggered reporting configuration accordingly. In particular, the event-triggered reporting configuration indicates a list of candidate cells and a list of events configured for the list of candidate cells. It should be noted that in some cases, a same event configuration may be configured to list of candidate cells, that is, all of the candidate cells have a same list of events. Alternatively, in some cases, the event configuration is configured per candidate cell, the event configurations for different candidate cells are independently from each other.

[0116] Then, based on at least one event in the list of events being detected for a candidate cell of the list of candidate cells, the first apparatus 210 pre-processes a candidate cell configuration of the candidate cell.

[0117] In order to trigger a cell switch to the candidate cell, the first apparatus 210 may transmit (340-1) a measurement report of the candidate cell to the second apparatus 220. In response to receiving (340-2) the measurement report, the second apparatus 220 maytransmit (350-1) a switch command (such as, a MAC CE) to the first apparatus 210, and the first apparatus 210 receives (350-2) the switch command accordingly.

[0118] The first apparatus 21 may determine (360-1) and / or the second apparatus 220 may determine (360-2) the cell switch delay based on at least one of the following:• whether the candidate cell configuration of the candidate cell has been pre-processed,• a starting time point for pre-processing the candidate cell configuration, or• an ending time point for pre-processing the candidate cell configuration.

[0119] In some example embodiments, the first apparatus 210 may start to pre-process the candidate cell configuration in response to one of the following:• a detection of the at least one of event,• a transmission of a measurement report triggered by the at least one event, or• a reception of acknowledgement of the measurement report.

[0120] In some example embodiments, the first apparatus 210 may perform early decoding and / or validity check on the candidate cell configuration. In some example embodiments, the cell switch delay may be determined based at least in part on a first parameter. In this event, the first apparatus 210 and / or the second apparatus 220 may set the first parameter to be a first value based on that the early decoding and / or validity check has been performed, and may set the first parameter to be a second value larger than the first value based on that the early decoding and / or validity check has not been performed accordingly. One example first parameter may be TLTM -RRC-processing, where TLTM-RRC- processing is the time for ASN. l decoding and validity / compliance check for the RRC configuration of the LTM target cell indicated in the LTM cell switch command.

[0121] Alternatively, in some embodiments, the first apparatus 210 may apply at least one parameter of the candidate cell configuration. In some example embodiments, the cell switch delay may be determined based at least in part on a second parameter. In this event, the first apparatus 210 may set the second parameter to be a first value based on that at least part of the at least one parameter has been applied, and set the second parameter to be a second value larger than the first value based on that the at least one parameter has not been applied accordingly. One example second parameter may be TLTM -processing, whereTLTM -processing is the time for UE processing, consisting of applying the target cell parameters and L1 / L2 change.

[0122] In some example embodiments, whether and when to perform the pre-processing may be informed to the second apparatus 220, such that the second apparatus 220 may determine cell switch delay properly. Specifically, the first apparatus 210 may transmit a message to the second apparatus, where the message comprises at least one of the following:• an indication whether the candidate cell configuration of the candidate cell has been pre-processed by the first apparatus,• an indication that the first apparatus 210 is to pre-process the candidate cell configuration,• an indication of a starting time point for pre-processing the candidate cell configuration, or• an indication of an ending time point for pre-processing the candidate cell configuration.

[0123] In one embodiment, the message may be the event -triggered report (such as, LI measurement report). Alternatively, the message may be in a separate message different from the event -triggered report.

[0124] In some embodiments, whether the pre-processing procedure has been performed may be determined based on some default rules. As one example, the second apparatus 220 may determine that pre-processing the candidate cell configuration has been performed by the first apparatus 210 based on that a time length between a starting time point for pre-processing and the cell switch command is larger than or equal to a threshold. Accordingly, the second apparatus 220 may determine that pre-processing the candidate cell configuration has not been performed by the first apparatus 210 based on that the time length between the starting time point and the cell switch command is smaller than or equal to a threshold.

[0125] Optionally, the first apparatus may report its capability-related information on the preparation to the second apparatus 220. Specifically, in some example embodiments, the first apparatus 210 may transmit capability -related information to the second apparatus 220, where the capability -related information indicates that the first apparatus 210supports pre-processing the candidate cell configuration based on detecting the at least one event.

[0126] Optionally, whether the preparation is allowed to performed may be controlled by the second apparatus 220. Specifically, in some example embodiments, the event- triggered reporting configuration transmitted by the second apparatus 220 may comprise an indication for enabling or disabling pre-processing the candidate cell configuration associated to event triggered reporting condition becoming fulfilled.

[0127] Example embodiments where the preparation comprises time / frequency synchronization for the candidate cell will be discussed by referring to FIG. 3B.

[0128] As illustrated in FIG. 3B, the second apparatus 220 transmit (310-1) an event- triggered reporting configuration (such as, an LTM-based configuration, or a layer 3 (L3) event-triggered reporting configuration), and the first apparatus 210 receives (320-2) the event-triggered reporting configuration accordingly. In particular, the event-triggered reporting configuration indicates a list of candidate cells and a list of events configured for the list of candidate cells. It should be noted that in some cases, a same event configuration may be configured to list of candidate cells, that is, all of the candidate cells have a same list of events. Alternatively, in some cases, the event configuration is configured per candidate cell, the event configurations for different candidate cells are independently from each other.

[0129] Then, based on at least one event in the list of events being detected for a candidate cell of the list of candidate cells, the first apparatus 210 performs preparation comprising time / frequency synchronization for the candidate cell.

[0130] In order to trigger a cell switch to the candidate cell, the first apparatus 210 may transmit (340-1) a measurement report of the candidate cell to the second apparatus 220. In response to receiving (340-2) the measurement report, the second apparatus 220 may transmit (350-1) a switch command (such as, a MAC CE) to the first apparatus 210, and the first apparatus 210 receives (350-2) the switch command accordingly.

[0131] The first apparatus 210 may determine (360-1) and / or the second apparatus 220 may determine (360-2) a switch-related delay based on at least one of the following:• whether the time / frequency synchronization for the candidate cell has been performed,• a starting time point for performing the time / frequency synchronization for the candidate cell, or• an ending time point for performing the time / frequency synchronization for the candidate cell.

[0132] In some example embodiments, the switch-related delay may comprise at least one of the following: a cell switch delay, a physical downlink control channel (PDCCH) ordered random access channel (RACH) delay, or a transmission configuration indicator (TCI) state activation delay.

[0133] In some example embodiments, the first apparatus 210 may start to perform the time / frequency synchronization in response to one of the following:• a detection of the at least one of event,• a transmission of a measurement report triggered by the at least one event, or• a reception of acknowledgement of the measurement report.

[0134] In some example embodiments, the first apparatus 210 may perform the time / frequency synchronization in accordance with a determination that none of TCI states in the activated TCI state list are associated with the candidate cell. Alternatively, in some example embodiments, the first apparatus 210 may perform the time / frequency synchronization in accordance with a determination that at least one transmission configuration indicator (TCI) state associated with candidate cell is comprised in an activated TCI state list. . Alternatively, or in addition, in some example embodiments, the first apparatus 210 may perform the time / frequency synchronization in accordance with a determination that at least one reference signal (RS) of the candidate cell that triggered the measurement report through a configured condition becoming fulfilled is associated to a TCI state in an activated TCI state list, for example, the TCI state in an activated TCI state list has a QCL relationship to the at least one reference signal (RS) that triggered the measurement report.

[0135] In some example embodiments, the switch-related delay may be determined based at least in part on a parameter. In this event, the first apparatus 210 and / or the second apparatus 220 may set the parameter to be a first value based on that the time / frequency synchronization has been performed and may set the parameter to be a second value largerthan the first value based on that the time / frequency synchronization has not been performed.

[0136] In some example embodiments, the parameter may comprise at least one of the following: a first parameter for fine time and / or frequency synchronization, or a second parameter for reference signal (RS) processing (such as, a second parameter for synchronization signal and physical broadcast channel (PBCH) block (SSB) processing).

[0137] One example first parameter may be Tfirst-RS, where Tfirst-Rs is the time for fine time tracking and acquiring full timing information of the target cell, which may be defined as the time until the first SSB transmission after processing the cell switch command. Another example second parameter may be TRS-PTOC, where TRS-PTOC is the time for SSB processing.

[0138] In some example embodiments, whether and when to perform the preparation comprising time / frequency synchronization for the candidate cell may be informed to the second apparatus 220, such that the second apparatus 220 may determine cell switch delay properly. Specifically, the first apparatus 210 may transmit a message to the second apparatus, where the message comprises at least one of the following:• an indication whether the time / frequency synchronization has been performed by the first apparatus,• an indication that the first apparatus 210 is to perform the time / frequency synchronization,• an indication of a starting time point for performing the time / frequency synchronization, or• an indication of an ending time point for performing the time / frequency synchronization.

[0139] In one embodiment, the message may be the event -triggered report (such as, LI measurement report). Alternatively, the message may be in a separate message different from the event -triggered report.

[0140] In some embodiments, whether the pre-processing procedure has been performed may be determined based on some default rules. As one example, the second apparatus 220 may determine that the time / frequency synchronization has been performed by the first apparatus 210 based on that a time length between a starting time point forperforming the preparation and the cell switch command is larger than or equal to a threshold. Accordingly, the second apparatus 220 may determine that the time / frequency synchronization has not been performed by the first apparatus 210 based on that the time length between the starting time point and the cell switch command is smaller than or equal to a threshold.

[0141] Optionally, the first apparatus may report its capability-related information on the preparation to the second apparatus 220. Specifically, in some example embodiments, the first apparatus 210 may transmit capability -related information to the second apparatus 220, where the capability -related information indicates that the first apparatus 210 supports the preparation comprising the time / frequency synchronization based on detecting the at least one event.

[0142] Optionally, whether the preparation is allowed to performed may be controlled by the second apparatus 220. Specifically, in some example embodiments, the event- triggered reporting configuration transmitted by the second apparatus 220 may comprise an indication for enabling or disabling performing the preparation comprising the time / frequency synchronization.

[0143] Example embodiments where the preparation comprises user equipment (UE)- based timing advance (TA) estimation for the candidate cell will be discussed by referring to FIG. 3B.

[0144] As illustrated in FIG. 3B, the second apparatus 220 transmit (310-1) an event- triggered reporting configuration (such as, an LTM-based configuration, or a layer 3 (L3) event-triggered reporting configuration), and the first apparatus 210 receives (320-2) the event-triggered reporting configuration accordingly. In particular, the event-triggered reporting configuration indicates a list of candidate cells and a list of events configured for the list of candidate cells. It should be noted that in some cases, a same event configuration may be configured to list of candidate cells, that is, all of the candidate cells have a same list of events. Alternatively, in some cases, the event configuration is configured per candidate cell, the event configurations for different candidate cells are independently from each other.

[0145] Then, based on at least one event in the list of events being detected for a candidate cell of the list of candidate cells, the first apparatus 210 performs the preparationcomprising UE-based TA estimation for the candidate cell.

[0146] In order to trigger a cell switch to the candidate cell, the first apparatus 210 may transmit (340-1) a measurement report of the candidate cell to the second apparatus 220. In response to receiving (340-2) the measurement report, the second apparatus 220 may transmit (350-1) a switch command (such as, a MAC CE) to the first apparatus 210, and the first apparatus 210 receives (350-2) the switch command accordingly.

[0147] The first apparatus 21 may determine (360-1) and / or the second apparatus 220 may determine (360-2) the cell switch delay and whether the cell switch is RACH-based or RACH-less based on at least one of the following:• whether the UE-based TA estimation for the candidate cell has been performed,• a starting time point for performing the UE-based TA estimation for the candidate cell, or• an ending time point for performing the UE-based TA estimation for the candidate cell.

[0148] In some example embodiments, the first apparatus 210 may start to perform the UE-based TA estimation in response to one of the following:• a detection of the at least one of event,• a transmission of a measurement report triggered by the at least one event, or• a reception of acknowledgement of the measurement report.

[0149] In some example embodiments, whether and when to perform the preparation comprising UE-based TA estimation for the candidate cell may be informed to the second apparatus 220, such that the second apparatus 220 may determine cell switch delay properly. Specifically, the first apparatus 210 may transmit a message to the second apparatus, where the message comprises at least one of the following:• an indication whether the preparation or the UE-based TA estimation has been performed by the first apparatus,• an indication that the first apparatus 210 is to perform the preparation or the UE-based TA estimation,• an indication of a starting time point for performing the preparation or the UE-basedTA estimation, or• an indication of an ending time point for performing the preparation or the UE-based TA estimation.

[0150] In one embodiment, the message may be the event -triggered report (such as, LI measurement report). Alternatively, the message may be in a separate message different from the event -triggered report.

[0151] In some embodiments, whether the preparing comprising the UE-based TA estimation has been performed may be determined based on some default rules. As one example, the second apparatus 220 may determine that the preparation comprising the UE-based on TA has been performed by the first apparatus 210 based on that a time length between a starting time point for performing the preparation and the cell switch command is larger than or equal to a threshold. According, the second apparatus 220 may determine that the preparation comprising the UE-based on TA has not been performed by the first apparatus 210 based on that the time length between the starting time point and the cell switch command is smaller than or equal to a threshold.

[0152] Optionally, the first apparatus may report its capability -related information on the preparation to the second apparatus 220. Specifically, in some example embodiments, the first apparatus 210 may transmit capability -related information to the second apparatus 220, where the capability -related information indicates that the first apparatus 210 supports the preparation comprising the UE-based on TA estimation based on detecting the at least one event.

[0153] Optionally, whether the preparation is allowed to performed may be controlled by the second apparatus 220. Specifically, in some example embodiments, the event- triggered reporting configuration transmitted by the second apparatus 220 may comprise an indication for enabling or disabling performing the preparation comprising the UE- based on TA estimation based on detecting the at least one event. In some example embodiments, the indication may allow the UE not to perform UE based TA estimation before a condition for event triggered reporting is fulfilled. Alternatively, in some example embodiments, the indication may instruct the UE to not wait for the reporting condition to become fulfilled and perform UE based TA estimation regardless of whether the reporting condition is fulfilled.

[0154] Although the above example embodiments are discussed separately, it should be noted that the preparation may comprise more than one operation. In other words, the above discussed example embodiments may be implemented in combination manner. As one example, the preparation may comprise two or more operations of: pre-processing a candidate cell configuration of the candidate cell, time / frequency synchronization, user equipment (UE)-based timing advance (TA) estimation, and other preparation procedures. In this event, the cell switch delay may be determined based on multiple preparation procedures. Merely for brevity, such simply stacked implementation examples will not be discussed in detail anymore.

[0155] In some cases, when the UE is configured with event-triggered LI reporting for multiple LTM candidate cells and more than one of these candidate cells fulfill the event condition, the UE may not be able to perform the preparation procedure(s) on all the triggered candidate cells as discussed above. If so, the UE may select one or more candidate cells to perform the preparation procedure(s). Example embodiments about how to select one or more candidate cells to perform the preparation procedure(s) will be discussed as below.

[0156] As illustrated in FIG. 3B, the second apparatus 220 transmit (310-1) an event- triggered reporting configuration (such as, an LTM-based configuration, or a layer 3 (L3) event-triggered reporting configuration), and the first apparatus 210 receives (320-2) the event-triggered reporting configuration accordingly. In particular, the event-triggered reporting configuration indicates a list of candidate cells and a list of events configured for the list of candidate cells. It should be noted that in some cases, a same event configuration may be configured to list of candidate cells, that is, all of the candidate cells have a same list of events. Alternatively, in some cases, the event configuration is configured per candidate cell, the event configurations for different candidate cells are independent from each other.

[0157] Next, the first apparatus 210 performs (320) measurements on the list of candidate cells, based on the LTM-based configuration. Based on the measurements result, the first apparatus 210 determines a plurality of candidate cells, at least one event in the list of events being detected for each of the plurality of candidate cells.

[0158] In some embodiments, the first apparatus 210 determines at least one candidate cell from the plurality of candidate cells to perform preparation of cell switch based on aplurality of signal qualities of the plurality of candidate cells. In some example embodiments, the signal quality may comprise at least one of the following: a signal quality associated with a specific event, a reference signal receiving power (RSRP), a signal to interference plus noise ratio (SINR), a received signal strength indication (RSSI), or a reference signal receiving quality (RSRQ).

[0159] Alternatively, or in addition, in some embodiments, the first apparatus 210 determines at least one candidate cell from the plurality of candidate cells to perform preparation of cell switch based on a plurality of time points at which the plurality of candidate cell fulfill respective reporting conditions.

[0160] Alternatively, or in addition, in some embodiments, the first apparatus 210 determines at least one candidate cell from the plurality of candidate cells to perform preparation of cell switch based on a plurality of events detected on the plurality of candidate cell. For example, the candidate cell on which a specific Event is detected.

[0161] Alternatively, or in addition, in some embodiments, the first apparatus 210 determines at least one candidate cell from the plurality of candidate cells to perform preparation of cell switch based on a priority order of the plurality of candidate cells.

[0162] Alternatively, or in addition, in some embodiments, the first apparatus 210 determines at least one candidate cell from the plurality of candidate cells to perform preparation of cell switch based on a plurality of switch types of the plurality of candidate cells. In some example embodiments, the switch type comprises at least one of the following: an intra-the next Generation Node B (gNB) switch, an inter-gNB switch, an intra-centralized unit (CU) switch, or an inter-CU switch.

[0163] Alternatively, or in addition, in some embodiments, first apparatus 210 determines at least one candidate cell from the plurality of candidate cells to perform preparation of cell switch based on a plurality of switch states of the plurality of candidate cells. In some example embodiments, the switch state may be associated with a completion state of at least one of the following: pre-processing a candidate cell configuration of the candidate cell, a time / frequency synchronization, a user equipment (UE)-based timing advance (TA) estimation, a transmission configuration indicator (TCI) state activation with downlink synchronization, a random access channel (RACH)-based TA acquisition, or a physical downlink control channel (PDCCH) ordered RACH preamble transmission.

[0164] Alternatively, or in addition, in some embodiments, first apparatus 210 determines at least one candidate cell from the plurality of candidate cells to perform preparation of cell switch based on a plurality of cell identities of the plurality of candidate cells. For example, the candidate cell(s) with lower identify may be select to perform the preparation of cell switch.

[0165] In some embodiments, parameters / configurations / rules used for selecting the candidate cell(s) may be configured by the second apparatus 220. For example, in some example embodiments, the event-triggered reporting configuration may comprise at least one of the following:• an indication for enabling or disabling performing the preparation,• an event priority order used by the first apparatus 210 to determine the at least one candidate cell from the plurality of candidate cells,• a candidate cell priority order used by the first apparatus 210 to determine the at least one candidate cell from the plurality of candidate cells,• a switch type priority order used by the first apparatus 210 to determine the at least one candidate cell from the plurality of candidate cells, or• at least one rule used by the first apparatus 210 to determine the at least one candidate cell from the plurality of candidate cells.

[0166] Optionally, the first apparatus 210 may report its capability -related information on performing the preparation to the second apparatus 220. Specifically, in some example embodiments, the first apparatus 210 may transmit capability -related information to the second apparatus 220, where the capability-related information indicates at least of the following: the first apparatus 210 supporting the preparation, the specific preparation procedure supported by the first apparatus 210, or a maximum number of candidate cells on which the first apparatus 210 is capable of performing preparation and so on.

[0167] Merely for a better understanding of the above processes, some example embodiments will be further discussed, where UE is used as an example of the first apparatus 210 and the gNB is used as an example of the second apparatus 220.

[0168] In a nutshell, when a condition for LI event triggered reporting becomes fulfilled for an LTM candidate cell, the UE shall do one or more of the following preparationoperations for this candidate cell either as soon as the event condition becomes fulfilled or at the time of reporting (i.e., the reporting occasion in which the report is sent or when the report reception has been acknowledged (i.e., in case the report requires acknowledge, e.g., when report is sent over PUSCH or via MAC-CE): 1) Initiating pre-processing of the LTM candidate cell configuration; 2) Performing fine time / frequency (T / F) synchronization; and / or 3) Performing UE-based TA estimation.

[0169] When the UE has performed one or more of the above preparation operation(s) before the cell switch based on event-triggered reporting, the UE is not allowed time for these processes in the cell switch delay (i.e., the UE cell switch delay may omit one or more delay components related to the above processes).

[0170] Optionally, the UE may indicate its capability in terms of which operation(s) could be supported / performed upon an event is fulfilled for event triggered LI measurement reporting. The UE may further indicate for how many RSs / cells it can support for certain operation(s).

[0171] If the event condition becomes fulfilled for more than one candidate cells at the same time and the UE is not capable of doing preparation operation(s) for all these candidate cells, the UE may prioritize preparation operation(s) for some of the candidate cells based on predefined conditions or network configuration.

[0172] Additionally, in some embodiment, the preparation operation(s) may be applied for all events that trigger LI report or only to some of them. In one example, the preparation operation(s) may be applied for one or more predefined or configured event. In another example, the preparation operation(s) may be applied for an event-triggered reporting configuration.

[0173] In one embodiment, the UE may indicate either in the event-triggered report or in a separate message which of operation(s) have been performed based on LI reporting event condition becoming fulfilled.

[0174] In another embodiment, the UE will not send the event -triggered LI report before one or more of the preparation step(s) have been performed.

[0175] Reference is now made to FIG. 4A and 4B, which illustrate signaling flows 400A and 400B of communication in accordance with some embodiments of the presentdisclosure.

[0176] In the example of FIG. 4A and FIG. 4B, the UE is configured with LI measurements and event -triggered LI measurement reporting for one or more LTM candidate cells (i.e., cell configurations of candidate cells physical cell identifier 2 (PCI 2) and PCI 3), for example, the LTM configuration comprises: event configuration, measurement configuration, event-based reporting configuration. Optionally, the LTM configuration may define / enable / disable pre-processing of LTM configuration based on event and additional configuration for selection prioritization).

[0177] The UE will evaluate based on measurements whether the condition for the event triggered reporting becomes fulfilled for the configured event.

[0178] When the event condition becomes fulfilled, LI event -triggered reporting delay may be introduced, which comprises for example one Ll-RSRP measurement period within which the UE may realize that the condition is fulfilled. However, the delay requirement for LI event triggered reporting may also be defined differently. The UE may, e.g., send the report immediately after the condition becomes fulfilled or the delay may include additional components.

[0179] In some embodiments, UE may perform preparation operation(s) based on event condition becoming fulfilled at the time of event condition becoming fulfilled (as illustrated at block 410 in FIG. 4 A), or event triggered reporting being sent (as illustrated at block 450 in FIG. 4 A), or acknowledgement of Event triggered reporting is received.

[0180] The UE shall perform the preparation operation(s): pre-processing of LTM candidate cell configuration (referred to as preparation #1). This means that the UE performs a) early ASN.1 decoding and validity check and may also additionally perform b) other UE processing.

[0181] In some embodiments, depending on whether operation a) operation b), or operations a) and b) are performed, once the UE receives cell switch command, TLTM-RRC- processing and / or TLTM -processing may be considered as equals to zero when determining the cell switch delay.

[0182] In one embodiment, the UE may still be given some time for processing during the cell switch, and the value of TLTM -processing may be larger than zero but lower thanwithout event-triggered reporting (or without event-triggered reporting based preprocessing).

[0183] Alternatively, in some embodiments, The UE shall perform the preparation comprising fine (DL) T / F synchronization (referred to as preparation #2). In some embodiments, while performing the measurement after the event condition becomes fulfilled and before sending the measurement report, or immediately after sending the report, the UE shall also acquire fine time / frequency synchronization of the cell for this cell. In some embodiments, when the UE has acquired fine T / F synchronization, the UE is not allowed time to do this during TCI state activation, PDCCH ordered RACH procedure or cell switch (Tfirst-RS and TRS-PTOC = 0. In some embodiments, T / F tracking may apply until TCI state activation, PDCCH order or cell switch, or it may apply for a predefined time, after which the UE is not required to have fine T / F synchronization with the target cell and Tfirst-Rs and TRS -proc 0.

[0184] The UE may perform this operation for the cell the event-triggered condition becomes fulfilled: Either only if TCI state(s) of this cell are on the active TCI state list when the event condition becomes fulfilled, or if TCI state(s) associated with the reference signal (RS) that triggered the report for a candidate cell are on the active TCI state list, or if there is no TCI state on the active TCI state list associated with the cell / beam (for which event is met), or in any case.

[0185] Alternatively, in some embodiments, the UE shall perform the preparation comprising UE-based TA estimation (referred to as preparation #3). If network has configured the UE to do UE based TA estimation for a candidate cell for which an event condition becomes fulfilled, the UE shall perform and / or initiate TA estimation once the event condition becomes fulfilled.

[0186] In some embodiments, when the UE is configured with event -triggered LI reporting for multiple LTM candidate cells, and more than one of these cells fulfill the event condition, the UE may not be able to perform one or more of steps 1-3 to all of these cells. In such scenario, the UE may be allowed to perform one or more of steps 1-3 for a subset of the cells for which event condition becomes fulfilled according to UE capability.

[0187] In some embodiments, the selection of cells for which the UE shall perform the preparation(s) may be based on signal quality of the candidate cell. In some embodiments,the signal quality of the candidate cell may be absolute signal level (e.g. Ll-RSRP or L3- RSRP), where the UE performs the preparation(s) for the candidate cell(s) with highest signal level. The signal quality may refer to cell quality or RS set quality or quality of a reference resource (such as RS of the activated TCI state). Alternatively, the signal quality of the candidate cell may be a signal level related to the configured event (when different events are configured for different cells).

[0188] In some embodiments, the selection of cells for which the UE shall perform the preparation(s) may be based on a network defined priority order. That is, UE prioritizes the candidate cells in the order which they are configured in the LTM candidate cell configuration. Additionally, the network may provide a list which includes a priority order for candidate cells based on serving cell.

[0189] In some embodiments, the UE may be set always to prioritize intra-CU cell switch over inter-CU cell switch, (as an example, network may prioritize intra-CU cell switch over inter-CU switch).

[0190] Additionally, in some embodiments, whether the certain process / step applies for a candidate cell / beam or not may be configured per candidate cell / beam.

[0191] In some embodiments, the selection of cells for which the UE shall perform the preparation(s) may be based on: type of the configured event, e.g. prioritize cells that are configured with event LTM5.

[0192] In some embodiments, the selection of cells for which the UE shall perform the preparation(s) may be based on: the order in which the events were triggered.

[0193] In some embodiments, the selection of cells for which the UE shall perform the preparation(s) may be based on: the status of already performed step(s). For example, the UE may prioritize candidate cells / beams for a certain step (e.g., preparation #1 if one or more (e.g., preparation #2 or / and preparation #3) of other steps have already been performed for that cell / beams, e.g., the UE may prioritize candidate cells / beams for preprocessing (preparation #1) if there is TCI state(s) associated with the cell / beam is on active TCI state list (preparation #2) or / and UE-based TA acquisition has been performed (preparation #3) for that cell / beam based on the status of RACH-based TA acquisition, if any.

[0194] For example, the UE may prioritize candidate cell / beams for a certain step (e.g., preparation #1 and / or preparation #2 and / or preparation #3) if the UE has performed a PRACH transmission (e.g., PDCCH ordered PRACH transmission) towards that cell or using that beam.

[0195] In some embodiments, if the UE is performing one of the preparation #1 and / or preparation #2 and / or preparation #3, an indication towards the network may be transmitted. From this indication the network can calculate the exact processing delay upon cell switch without the corresponding components.

[0196] In some embodiments, the indication may be a specific indication per preparation #l / #2 / #3 which indicates UE has or will perform the processing. Alternatively, in some embodiments, the indication may be an event triggered measurement report indicating the cell switch components.

[0197] In another option, whether a certain step has been performed or not may be determined based on the value of the duration (Tms) between the time instance when the UE starts performing preparation #1 and / or preparation #2 and / or preparation #3 (e.g., when event-triggered reporting is sent or other conditions as mentioned above) and the cell switch. Minimum delay(s) / duration(s), e.g., Xmsmay be defined. If the T is larger than X, then it can be assumed that the certain step has been performed; otherwise, not.

[0198] In yet another embodiment, there is no indication from the UE to the network about performing preparation #1 and / or preparation #2 and / or preparation #3, but the UE will send the event -triggered LI report only after one or more of preparations 1 to 3 have been performed depending on UE capability and the requirement. In other words, one or more of preparations #1 to #3 are calculated in the LI event triggered reporting delay and when the network receives the report, it knows that the UE has performed one or more of preparations #1 to #3 depending on the requirement and UE capability.

[0199] The above may be implemented in cell switch delay requirement.

[0200] It should be noted that similar discussion as for Tfirst-Rs and TRS-PTOC may also be implemented for PDCCH ordered RACH delay and TCI state activation delay after event- triggered LI reporting. Example Method

[0201] FIG. 5 shows a flowchart of an example method 500 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 500 will be described from the perspective of the first apparatus 210 in FIG. 2.

[0202] At block 510, the first apparatus 210 receives, from a second apparatus, an event- triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells.

[0203] At block 520, based on at least one event in the list of events being detected for a candidate cell of the list of candidate cells, the first apparatus 210 pre-processes a candidate cell configuration of the candidate cell.

[0204] At block 530, the first apparatus 210 receives, from the second apparatus, a switch command of the candidate cell transmitted by the second apparatus in response to receiving a measurement report of the candidate cell.

[0205] At block 540, the first apparatus 210 determines a cell switch delay based on at least one of the following: whether the candidate cell configuration of the candidate cell has been pre-processed, a starting time point for pre-processing the candidate cell configuration, or an ending time point for pre-processing the candidate cell configuration.

[0206] In some example embodiments, the first apparatus 210 starts to pre-process the candidate cell configuration in response to one of the following: a detection of the at least one of event, a transmission of a measurement report triggered by the at least one event, or a reception of acknowledgement of the measurement report.

[0207] In some example embodiments, the first apparatus 210 performs early decoding and / or validity check on the candidate cell configuration; or applies at least one parameter of the candidate cell configuration.

[0208] In some example embodiments, the first apparatus 210, based on that the early decoding and / or validity check has been performed, sets the first parameter to be a first value; or based on that the early decoding and / or validity check has not been performed, sets the first parameter to be a second value larger than the first value.

[0209] In some example embodiments, the first apparatus 210, based on that at least part of the at least one parameter has been applied, sets the second parameter to be a first value; or based on that the at least one parameter has not been applied, sets the second parameter to be a second value larger than the first value.

[0210] In some example embodiments, the first apparatus 210 transmits, to the second apparatus, a message comprising at least one of the following: an indication whether thecandidate cell configuration of the candidate cell has been pre-processed by the first apparatus, an indication that the first apparatus is to pre-process the candidate cell configuration, an indication of a starting time point for pre-processing the candidate cell configuration, or an indication of an ending time point for pre-processing the candidate cell configuration.

[0211] In some example embodiments, the first apparatus 210 transmits, to the second apparatus, a measurement report triggered by the at least one event on a condition that the candidate cell configuration has been pre-processed.

[0212] In some example embodiments, the first apparatus 210 transmits, to the second apparatus, capability -related information indicating that the first apparatus supports preprocessing the candidate cell configuration based on detecting the at least one event.

[0213] In some example embodiments, the event -triggered reporting configuration comprises an indication for enabling or disabling pre-processing the candidate cell configuration.

[0214] In some example embodiments, the event -triggered reporting configuration comprises at least one of the following: a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration, or a layer 3 (L3) event-triggered reporting configuration.

[0215] In some example embodiments, the first apparatus 210 comprises a terminal apparatus and the second apparatus 220 comprises a network apparatus.

[0216] FIG. 6 shows a flowchart of an example method 600 implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 600 will be described from the perspective of the second apparatus 220 in FIG. 2.

[0217] At block 610, the second apparatus 220 transmits, to a first apparatus, an event- triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells.

[0218] At block 620, the second apparatus 220 receives, from the first apparatus, a measurement report transmitted by the first apparatus in response to at least one event in the list of events being detected for a candidate cell of the list of candidate cells.

[0219] At block 630, the second apparatus 220 transmits, to the first apparatus, a switchcommand of the candidate cell in response to receiving the measurement report, and

[0220] At block 640, the second apparatus 220 determines a cell switch delay based on at least one of the following: whether a candidate cell configuration of the candidate cell has been pre-processed by the first apparatus, a starting time point for pre-processing the candidate cell configuration, or an ending time point for pre-processing the candidate cell configuration.

[0221] In some example embodiments, the second apparatus 220 receives, from the first apparatus, a message comprising at least one of the following: an indication whether the candidate cell configuration of the candidate cell has been pre-processed by the first apparatus, an indication that the first apparatus is to pre-process the candidate cell configuration, an indication of a starting time point for pre-processing the candidate cell configuration, an indication of an ending time point for pre-processing the candidate cell configuration; and determining the cell switch delay based on the message.

[0222] In some example embodiments, the second apparatus 220 determines that preprocessing the candidate cell configuration has been performed by the first apparatus based on that a time length between a starting time point for pre-processing and the cell switch command is larger than or equal to a threshold; or determines that pre-processing the candidate cell configuration has not been performed by the first apparatus based on that the time length between the starting time point and the cell switch command is smaller than or equal to a threshold.

[0223] In some example embodiments, the second apparatus 220 determines that preprocessing the candidate cell configuration has been performed by the first apparatus in response to receiving the measurement report.

[0224] In some example embodiments, the first apparatus starts to pre-process the candidate cell configuration in response to one of the following: a detection of the at least one of event, a transmission of the measurement report triggered by the at least one event, or a reception of acknowledgement of the measurement report.

[0225] In some example embodiments, the second apparatus 220, based on that the early decoding and / or validity check has been performed, sets the first parameter to be a first value; or based on that the early decoding and / or validity check has not been performed, sets the first parameter to be a second value larger than the first value.

[0226] In some example embodiments, the second apparatus 220, based on that at least part of the at least one parameter has been applied, sets the second parameter to be a first value; or based on that the at least one parameter has not been applied, sets the second parameter to be a second value larger than the first value.

[0227] In some example embodiments, the second apparatus 220 receives, from the first apparatus, capability -related information indicating that the first apparatus supports preprocessing the candidate cell configuration based on detecting the at least one event.

[0228] In some example embodiments, the event-triggered reporting configuration comprises an indication for enabling or disabling pre-processing the candidate cell configuration.

[0229] In some example embodiments, the event-triggered reporting configuration comprises at least one of the following: a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration, or a layer 3 (L3) event-triggered reporting configuration.

[0230] In some example embodiments, the first apparatus 210 comprises a terminal apparatus and the second apparatus 220 comprises a network apparatus.

[0231] FIG. 7 shows a flowchart of an example method 700 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 700 will be described from the perspective of the first apparatus 210 in FIG. 2.

[0232] At block 710, the first apparatus 210 receives, from a second apparatus, an event- triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells.

[0233] At block 720, based on at least one event in the list of events being detected for a candidate cell of the list of candidate cells, the first apparatus 210 performs preparation comprising time / frequency synchronization for the candidate cell.

[0234] At block 730, the first apparatus 210 receives, from the second apparatus, a switch command of the candidate cell transmitted by the second apparatus in response to receiving a measurement report of the candidate cell.

[0235] At block 740, the first apparatus 210 determines a switch-related delay based on at least one of the following: whether the time / frequency synchronization for the candidatecell has been performed, a starting time point for performing the time / frequency synchronization for the candidate cell, or an ending time point for performing the time / frequency synchronization for the candidate cell.

[0236] In some example embodiments, the first apparatus 210 starts to perform the time / frequency synchronization in response to one of the following: a detection of the at least one of event, a transmission of a measurement report triggered by the at least one event, or a reception of acknowledgement of the measurement report.

[0237] In some example embodiments, the switch-related delay comprises at least one of the following: a cell switch delay, a physical downlink control channel (PDCCH) ordered random access channel (RACH) delay, or a transmission configuration indicator (TCI) state activation delay.

[0238] In some example embodiments, the first apparatus 210, based on that the time / frequency synchronization has been performed, sets the parameter to be a first value; or based on that the time / frequency synchronization has not been performed, sets the parameter to be a second value larger than the first value.

[0239] In some example embodiments, the parameter comprises at least one of the following: a first parameter for fine time and / or frequency synchronization, or a second parameter for reference signal (RS) processing.

[0240] In some example embodiments, the first apparatus 210 performs the time / frequency synchronization in accordance with a determination that: at least one transmission configuration indicator (TCI) state associated with candidate cell is comprised in an activated TCI state list, a reference signal (RS) associated with the candidate cell has a Quasi Co-Location (QCL) relationship with a transmission configuration indicator (TCI) state in an activated TCI state list, wherein a measurement result of the RS triggers the at least one event on the candidate cell, or none of TCI states in the activated TCI state list are associated with the candidate cell.

[0241] In some example embodiments, the first apparatus may perform the time / frequency synchronization for a pre-determined duration.

[0242] In some example embodiments, the first apparatus 210 transmits, to the second apparatus, a message comprising at least one of the following: an indication whether thetime / frequency synchronization has been performed by the first apparatus, an indication that the first apparatus is to perform the time / frequency synchronization, an indication of a starting time point for performing the time / frequency synchronization, or an indication of an ending time point for performing the time / frequency synchronization.

[0243] In some example embodiments, the first apparatus 210 transmits, to the second apparatus, a measurement report triggered by the at least one event on a condition that the time / frequency synchronization has been performed.

[0244] In some example embodiments, the first apparatus 210 transmits, to the second apparatus, capability-related information indicating that the first apparatus supports the preparation comprising the time / frequency synchronization based on detecting the at least one event.

[0245] In some example embodiments, the event-triggered reporting configuration comprises an indication for enabling or disabling performing the preparation comprising the time / frequency synchronization.

[0246] In some example embodiments, the event-triggered reporting configuration comprises at least one of the following: a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration, or a layer 3 (L3) event-triggered reporting configuration.

[0247] In some example embodiments, the first apparatus 210 comprises a terminal apparatus and the second apparatus 220 comprises a network apparatus.

[0248] FIG. 8 shows a flowchart of an example method 800 implemented at a second apparatus 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 second apparatus 220 in FIG. 2.

[0249] At block 810, the second apparatus 220 transmits, to a first apparatus, an event- triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells.

[0250] At block 820, the second apparatus 220 receives, from the first apparatus, a measurement report transmitted by the first apparatus in response to at least one event in the list of events being detected for a candidate cell of the list of candidate cells.

[0251] At block 830, the second apparatus 220 transmits, to the first apparatus, a switchcommand of the candidate cell in response to receiving the measurement report.

[0252] At block 840, the second apparatus 220 determines a switch-related delay based on at least one of the following: whether preparation comprising time / frequency synchronization for the candidate cell has been performed by the first apparatus, a starting time point for performing the time / frequency synchronization for the candidate cell, or an ending time point for performing the time / frequency synchronization for the candidate cell.

[0253] In some example embodiments, the second apparatus 220 receives, from the first apparatus, a message comprising at least one of the following: an indication whether the time / frequency synchronization has been performed by the first apparatus, an indication that the first apparatus is to perform the time / frequency synchronization, an indication of a starting time point for performing the time / frequency synchronization, or an indication of an ending time point for performing the time / frequency synchronization.

[0254] In some example embodiments, the second apparatus 220 determines that the time / frequency synchronization has been performed by the first apparatus based on that a time length between a starting time point for performing the preparation and the cell switch command is larger than or equal to a threshold; or determines that the time / frequency synchronization has not been performed by the first apparatus based on that the time length between the starting time point and the cell switch command is smaller than or equal to a threshold.

[0255] In some example embodiments, the second apparatus 220 determines that the time / frequency synchronization has been performed by the first apparatus in response to receiving the measurement report.

[0256] In some example embodiments, the first apparatus starts to perform the time / frequency synchronization in response to one of the following: a detection of the at least one of event, a transmission of the measurement report triggered by the at least one event, or a reception of acknowledgement of the measurement report.

[0257] In some example embodiments, the switch-related delay is determined based at least in part on a parameter, and the first apparatus is further caused to: based on that the time / frequency synchronization has been performed, setting the parameter to be a first value; or based on that the time / frequency synchronization has not been performed, settingthe parameter to be a second value larger than the first value.

[0258] In some example embodiments, the parameter comprises at least one of the following: a first parameter for fine time and / or frequency synchronization, or a second parameter for reference signal (RS) processing.

[0259] In some example embodiments, the second apparatus 220 receives, from the first apparatus, capability-related information indicating that the first apparatus supports the preparation comprising the time / frequency synchronization based on detecting the at least one event.

[0260] In some example embodiments, the event-triggered reporting configuration comprises an indication for enabling or disabling the preparation comprising the time / frequency synchronization.

[0261] In some example embodiments, the event -triggered reporting configuration comprises at least one of the following: a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration, or a layer 3 (L3) event-triggered reporting configuration.

[0262] In some example embodiments, the first apparatus 210 comprises a terminal apparatus and the second apparatus 220 comprises a network apparatus.

[0263] 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 210 in FIG. 2.

[0264] At block 910, the first apparatus 210 receives, from a second apparatus, an event- triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells.

[0265] At block 920, based on at least one event in the list of events being detected for a candidate cell of the list of candidate cells, the first apparatus 210 performs preparation comprising user equipment (UE)-based timing advance (TA) estimation for the candidate cell.

[0266] At block 930, the first apparatus 210 receives, from the second apparatus, a switch command of the candidate cell transmitted by the second apparatus in response to receiving a measurement report of the candidate cell.

[0267] At block 940, the first apparatus 210 determines a cell switch delay based on at least one of the following: whether the UE -based TA estimation for the candidate cell has been performed, a starting time point for performing the UE -based TA estimation for the candidate cell, or an ending time point for performing the UE -based TA estimation for the candidate cell.

[0268] In some example embodiments, the first apparatus 210 starts to perform the UE- based TA estimation in response to one of the following: a detection of the at least one of event, a transmission of a measurement report triggered by the at least one event, or a reception of acknowledgement of the measurement report.

[0269] In some example embodiments, the first apparatus 210 transmits, to the second apparatus, a message comprising at least one of the following: an indication whether the preparation or the UE-based TA estimation has been performed by the first apparatus, an indication that the first apparatus is to perform the preparation or the UE-based TA estimation, an indication of a starting time point for performing the preparation or the UE- based TA estimation, or an indication of an ending time point for performing the preparation or the UE-based TA estimation.

[0270] In some example embodiments, the preparation further comprises pre-processing a candidate cell configuration of the candidate cell.

[0271] In some example embodiments, the first apparatus 210 determines the cell switch delay further based on at least one of the following: whether the candidate cell configuration of the candidate cell has been pre-processed, a starting time point for preprocessing the candidate cell configuration, or an ending time point for pre-processing the candidate cell configuration.

[0272] In some example embodiments, the first apparatus 210 transmits, to the second apparatus, a message comprising at least one of the following: an indication whether the candidate cell configuration of the candidate cell has been pre-processed by the first apparatus, an indication that the first apparatus is to pre-process the candidate cell configuration, an indication of a starting time point for pre-processing the candidate cell configuration, or an indication of an ending time point for pre-processing the candidate cell configuration.

[0273] In some example embodiments, the preparation further comprisestime / frequency synchronization.

[0274] In some example embodiments, the first apparatus 210 determines the cell switch delay further based on at least one of the following: whether the time / frequency synchronization for the candidate cell has been performed, a starting time point for performing the time / frequency synchronization for the candidate cell, or an ending time point for performing the time / frequency synchronization for the candidate cell.

[0275] In some example embodiments, the first apparatus 210 transmits, to the second apparatus, a message comprising at least one of the following: an indication whether the time / frequency synchronization has been performed by the first apparatus, an indication that the first apparatus is to perform the time / frequency synchronization, an indication of a starting time point for performing the time / frequency synchronization, or an indication of an ending time point for performing the time / frequency synchronization.

[0276] In some example embodiments, the first apparatus 210 transmits, to the second apparatus, a measurement report triggered by the at least one event on a condition that the preparation has been performed.

[0277] In some example embodiments, the first apparatus 210 transmits, to the second apparatus, capability-related information indicating that the first apparatus supports the preparation based on detecting the at least one event.

[0278] In some example embodiments, the event-triggered reporting configuration comprises an indication for enabling or disabling performing the preparation.

[0279] In some example embodiments, the event-triggered reporting configuration comprises at least one of the following: a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration, or a layer 3 (L3) event-triggered reporting configuration.

[0280] In some example embodiments, the first apparatus 210 comprises a terminal apparatus and the second apparatus 220 comprises a network apparatus.

[0281] FIG. 10 shows a flowchart of an example method 1000 implemented at a second 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 second apparatus 220 in FIG. 2.

[0282] At block 1010, the second apparatus 220 transmits, to a first apparatus, an event -triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells.

[0283] At block 1020, the second apparatus 220 receives, from the first apparatus, a measurement report transmitted by the first apparatus in response to at least one event in the list of events being detected for a candidate cell of the list of candidate cells.

[0284] At block 1030, the second apparatus 220 transmits, to the first apparatus, a switch command of the candidate cell in response to receiving the measurement report.

[0285] At block 1040, the second apparatus 220 determines a cell switch delay based on at least one of the following: whether preparation comprising user equipment (UE)- based timing advance (TA) estimation for the candidate cell has been performed by the first apparatus, a starting time point for performing the UE-based TA estimation for the candidate cell, or an ending time point for performing the UE-based TA estimation for the candidate cell.

[0286] In some example embodiments, the second apparatus 220 receives, from the first apparatus, a message comprising at least one of the following: an indication whether the preparation or the UE-based TA estimation has been performed by the first apparatus, an indication that the first apparatus is to perform the preparation or the UE-based TA estimation, an indication of a starting time point for performing the preparation or the UE- based TA estimation, or an indication of an ending time point for performing the preparation or the UE-based TA estimation.

[0287] In some example embodiments, the preparation further comprises pre-processing a candidate cell configuration of the candidate cell.

[0288] In some example embodiments, the second apparatus 220 determines the cell switch delay further based on at least one of the following: whether the candidate cell configuration of the candidate cell has been pre-processed, a starting time point for preprocessing the candidate cell configuration, or an ending time point for pre-processing the candidate cell configuration.

[0289] In some example embodiments, the second apparatus 220 transmits, to the second apparatus, a message comprising at least one of the following: an indication whether the candidate cell configuration of the candidate cell has been pre-processed bythe first apparatus, an indication that the first apparatus is to pre-process the candidate cell configuration, an indication of a starting time point for pre-processing the candidate cell configuration, or an indication of an ending time point for pre-processing the candidate cell configuration.

[0290] In some example embodiments, the preparation further comprises time / frequency synchronization.

[0291] In some example embodiments, the second apparatus 220 determines the cell switch delay further based on at least one of the following: whether the time / frequency synchronization for the candidate cell has been performed, a starting time point for performing the time / frequency synchronization for the candidate cell, or an ending time point for performing the time / frequency synchronization for the candidate cell.

[0292] In some example embodiments, the first apparatus is further caused to: transmit, to the second apparatus, a message comprising at least one of the following: an indication whether the time / frequency synchronization has been performed by the first apparatus, an indication that the first apparatus is to perform the time / frequency synchronization, an indication of a starting time point for performing the time / frequency synchronization, or an indication of an ending time point for performing the time / frequency synchronization.

[0293] In some example embodiments, the second apparatus 220 determines that the preparation has been performed by the first apparatus based on that a time length between a starting time point for performing the preparation and the cell switch command is larger than or equal to a threshold; or determines that the preparation has not been performed by the first apparatus based on that the time length between the starting time point and the cell switch command is smaller than or equal to a threshold.

[0294] In some example embodiments, the second apparatus 220 determines that the preparation has been performed by the first apparatus in response to receiving the measurement report.

[0295] In some example embodiments, the first apparatus starts to perform the UE- based TA estimation in response to one of the following: a detection of the at least one of event, a transmission of the measurement report triggered by the at least one event, or a reception of acknowledgement of the measurement report.

[0296] In some example embodiments, the second apparatus 220 receives, from the first apparatus, capability-related information indicating that the first apparatus supports the preparation based on detecting the at least one event.

[0297] In some example embodiments, the event-triggered reporting configuration comprises an indication for enabling or disabling the preparation.

[0298] In some example embodiments, the event-triggered reporting configuration comprises at least one of the following: a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration, or a layer 3 (L3) event-triggered reporting configuration.

[0299] In some example embodiments, the first apparatus 210 comprises a terminal apparatus and the second apparatus 220 comprises a network apparatus.

[0300] 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 210 in FIG. 2.

[0301] At block 1110, the first apparatus 210 receives, from a second apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells.

[0302] At block 1120, the first apparatus 210 determines a plurality of candidate cells, at least one event in the list of events being detected for each of the plurality of candidate cells.

[0303] At block 1130, the first apparatus 210 determines at least one candidate cell from the plurality of candidate cells to perform preparation of cell switch based on at least one of the following: a plurality of signal qualities of the plurality of candidate cells, a plurality of time points at which the plurality of candidate cell fulfill respective reporting conditions, a plurality of events detected on the plurality of candidate cell, a priority order of the plurality of candidate cells, a plurality of switch types of the plurality of candidate cells, a plurality of switch states of the plurality of candidate cells, or a plurality of cell identities of the plurality of candidate cells.

[0304] At block 1140, the first apparatus 210 performs the cell switch preparation on at least one candidate cell.

[0305] In some example embodiments, the preparation of cell switch comprises at least one of the following: pre-processing a candidate cell configuration of the candidate cell, time / frequency synchronization, or user equipment (UE)-based timing advance (TA) estimation.

[0306] In some example embodiments, the first apparatus 210 starts to perform the preparation of cell switch in response to one of the following: a detection of the at least one of event, a transmission of a measurement report triggered by the at least one event, or a reception of acknowledgement of the measurement report.

[0307] In some example embodiments, the signal quality comprises at least one of the following: a signal quality associated with a specific event, a reference signal receiving power (RSRP), a signal to interference plus noise ratio (SINR), a received signal strength indication (RSSI), or a reference signal receiving quality (RSRQ).

[0308] In some example embodiments, the switch type comprises at least one of the following: an intra-the next Generation Node B (gNB) switch, an inter-gNB switch, an intra-centralized unit (CU) switch, or an inter-CU switch.

[0309] In some example embodiments, the switch state is associated with a completion state of at least one of the following: pre-processing a candidate cell configuration of the candidate cell, a time / frequency synchronization, a user equipment (UE)-based timing advance (TA) estimation, a transmission configuration indicator (TCI) state activation, a random access channel (RACH)-based TA acquisition, or a physical downlink control channel (PDCCH) ordered RACH preamble transmission.

[0310] In some example embodiments, the event -triggered reporting configuration comprises at least one of the following: an indication for enabling or disabling performing the preparation, an event priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, a candidate cell priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, a switch type priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, or at least one rule used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells.

[0311] In some example embodiments, the first apparatus 210 transmits, to the secondapparatus, capability-related information indicating at least of the following: the first apparatus supporting the preparation, or a maximum number of candidate cells on which the first apparatus is capable of performing preparation.

[0312] In some example embodiments, the event-triggered reporting configuration comprises at least one of the following: a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration, or a layer 3 (L3) event-triggered reporting configuration.

[0313] In some example embodiments, the first apparatus 210 comprises a terminal apparatus and the second apparatus 220 comprises a network apparatus.

[0314] FIG. 12 shows a flowchart of an example method 1200 implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 1200 will be described from the perspective of the second apparatus 220 in FIG. 2.

[0315] At block 1210, the second apparatus 220 generates, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells, wherein the LTM-based configuration comprises at least one of the following: an indication for enabling or disabling performing preparation of cell switch at the first apparatus, an event priority order used by the first apparatus to determine at least one candidate cell to perform the preparation of cell switch from a plurality of candidate cells, a candidate cell priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, a switch type priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, or at least one rule used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells.

[0316] At block 1220, the second apparatus 220 transmits the event -triggered reporting configuration to a first apparatus.

[0317] In some example embodiments, the preparation of cell switch comprises at least one of the following: pre-processing a candidate cell configuration of the candidate cell time / frequency synchronization, or user equipment (UE)-based timing advance (TA) estimation.

[0318] In some example embodiments, the first apparatus starts to perform thepreparation of cell switch in response to one of the following: a detection of the at least one of event, a transmission of a measurement report triggered by the at least one event, or a reception of acknowledgement of the measurement report.

[0319] In some example embodiments, the switch type comprises at least one of the following: an intra-the next Generation Node B (gNB) switch, an inter-gNB switch, an intra-centralized unit (CU) switch, or an inter-CU switch.

[0320] In some example embodiments, the switch state is associated with a completion state of at least one of the following: pre-processing a candidate cell configuration of the candidate cell, a time / frequency synchronization, a user equipment (UE)-based timing advance (TA) estimation, a transmission configuration indicator (TCI) state activation, a random access channel (RACH)-based TA acquisition, or a physical downlink control channel (PDCCH) ordered RACH preamble transmission.

[0321] In some example embodiments, the first apparatus transmits, to the second apparatus, capability-related information indicating at least of the following: the first apparatus supporting the preparation, or a maximum number of candidate cells on which the first apparatus is capable of performing preparation.

[0322] In some example embodiments, the event-triggered reporting configuration comprises at least one of the following: a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration, or a layer 3 (L3) event-triggered reporting configuration.

[0323] In some example embodiments, the first apparatus 210 comprises a terminal apparatus and the second apparatus 220 comprises a network apparatus.

[0324] FIG. 13 shows a flowchart of an example method 1300 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 1300 will be described from the perspective of the first apparatus 210 in FIG. 2.

[0325] At block 1310, the first apparatus 210 receives, from a second apparatus, a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells.

[0326] At block 1320, the first apparatus 210 performs, based on the LTM-based configuration, measurements on the list of candidate cells.

[0327] At block 1330, the first apparatus 210 determines, based on measurement results of the measurements, at least one event being detected for a candidate cell of the list of candidate cells.

[0328] At block 1340, the first apparatus 210 suspends a transmission of a layer 1 (LI) measurement report triggered by the at least one event until a reporting criterion is fulfilled, wherein the reporting criterion is determined to be fulfilled at least based on a preparation of cell switch has been performed.

[0329] In some example embodiments, the preparation of cell switch comprises at least one of the following: pre-processing a candidate cell configuration of the candidate cell, time / frequency synchronization, user equipment (UE)-based timing advance (TA) estimation, a transmission configuration indicator (TCI) state activation, a random access channel (RACH)-based TA acquisition, or a physical downlink control channel (PDCCH) ordered RACH preamble transmission.

[0330] In some example embodiments, the first apparatus 210 starts to perform the preparation of cell switch in response to one of the following: a detection of the at least one of event, a transmission of the LI measurement report triggered by the at least one event, or a reception of acknowledgement of the LI measurement report.

[0331] In some example embodiments, the measurement comprises at least one of the following: an LI signal quality associated with a specific event measurement, an LI reference signal receiving power (RSRP) measurement, an LI signal to interference plus noise ratio (SINR) measurement, an LI received signal strength indication (RSSI) measurement, or an LI reference signal receiving quality (RSRQ) measurement.

[0332] In some example embodiments, the first apparatus 210 comprises a terminal apparatus and the second apparatus 220 comprises a network apparatus.

[0333] FIG. 14 shows a flowchart of an example method 1400 implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 1400 will be described from the perspective of the second apparatus 220 in FIG. 2.

[0334] At block 1410, the second apparatus 220 transmits, to a first apparatus, a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration indicating and a list ofcandidate cells and a list of events configured for the list of candidate cells.

[0335] At block 1420, the second apparatus 220 receives, from the first apparatus, a layer 1 (LI) measurement report triggered by at least one event in the list of events being detected for a candidate cell of the list of candidate cells, wherein the LI measurement report is transmitted by the first apparatus in response to a reporting criterion being fulfilled, wherein the reporting criterion is determined to be fulfilled at least based on a preparation of cell switch has been performed.

[0336] In some example embodiments, the preparation of cell switch comprises at least one of the following: pre-processing a candidate cell configuration of the candidate cell, time / frequency synchronization, user equipment (UE)-based timing advance (TA) estimation, a transmission configuration indicator (TCI) state activation, a random access channel (RACH)-based TA acquisition, or a physical downlink control channel (PDCCH) ordered RACH preamble transmission.

[0337] In some example embodiments, the preparation of cell switch is performed by the first apparatus in response to one of the following: a detection of the at least one of event, a transmission of the LI measurement report triggered by the at least one event, or a reception of acknowledgement of the LI measurement report.

[0338] In some example embodiments, the second apparatus 220 determines that the preparation has been performed by the first apparatus in response to receiving the LI measurement report.

[0339] In some example embodiments, the second apparatus 220 determines a cell switch delay by assuming the preparation of cell switch has been performed by the first apparatus.

[0340] In some example embodiments, the measurement comprises at least one of the following: an LI signal quality associated with a specific event measurement, an LI reference signal receiving power (RSRP) measurement, an LI signal to interference plus noise ratio (SINR) measurement, an LI received signal strength indication (RSSI) measurement, or an LI reference signal receiving quality (RSRQ) measurement.

[0341] In some example embodiments, the first apparatus 210 comprises a terminal apparatus and the second apparatus 220 comprises a network apparatus.Example Apparatus, Device and Medium

[0342] In some example embodiments, a first apparatus capable of performing any of the method 500 (for example, the first apparatus 210 in FIG. 2) may comprise means for performing the respective operations of the method 500. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the first apparatus 210 in FIG. 2.

[0343] In some example embodiments, the first apparatus comprises means for receiving, from a second apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; means for, based on at least one event in the list of events being detected for a candidate cell of the list of candidate cells, pre-processing a candidate cell configuration of the candidate cell; means for receiving, from the second apparatus, a switch command of the candidate cell transmitted by the second apparatus in response to receiving a measurement report of the candidate cell; and means for determining a cell switch delay based on at least one of the following: whether the candidate cell configuration of the candidate cell has been pre- processed, a starting time point for pre-processing the candidate cell configuration, or an ending time point for pre-processing the candidate cell configuration.

[0344] In some example embodiments, the first apparatus 110 starts to pre-process the candidate cell configuration in response to one of the following: a detection of the at least one of event, a transmission of a measurement report triggered by the at least one event, or a reception of acknowledgement of the measurement report.

[0345] In some example embodiments, the first apparatus 110 performs early decoding and / or validity check on the candidate cell configuration; or applies at least one parameter of the candidate cell configuration.

[0346] In some example embodiments, the first apparatus further comprises: means for, based on that the early decoding and / or validity check has been performed, setting the first parameter to be a first value; or means for, based on that the early decoding and / or validity check has not been performed, setting the first parameter to be a second value larger than the first value.

[0347] In some example embodiments, the first apparatus further comprises: means for,based on that at least part of the at least one parameter has been applied, setting the second parameter to be a first value; or means for, based on that the at least one parameter has not been applied, setting the second parameter to be a second value larger than the first value.

[0348] In some example embodiments, the first apparatus 110 transmits, to the second apparatus, a message comprising at least one of the following: an indication whether the candidate cell configuration of the candidate cell has been pre-processed by the first apparatus, an indication that the first apparatus is to pre-process the candidate cell configuration, an indication of a starting time point for pre-processing the candidate cell configuration, or an indication of an ending time point for pre-processing the candidate cell configuration.

[0349] In some example embodiments, the first apparatus further comprises: means for transmitting, to the second apparatus, a measurement report triggered by the at least one event on a condition that the candidate cell configuration has been pre-processed.

[0350] In some example embodiments, the first apparatus further comprises: means for transmitting, to the second apparatus, capability-related information indicating that the first apparatus supports pre-processing the candidate cell configuration based on detecting the at least one event.

[0351] In some example embodiments, the event -triggered reporting configuration comprises an indication for enabling or disabling pre-processing the candidate cell configuration.

[0352] In some example embodiments, the event -triggered reporting configuration comprises at least one of the following: a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration, or a layer 3 (L3) event-triggered reporting configuration.

[0353] In some example embodiments, the first apparatus 110 comprises a terminal apparatus and the second apparatus 120 comprises a network apparatus.

[0354] In some example embodiments, a second apparatus capable of performing any of the method 600 (for example, the second apparatus 220 in FIG. 2) may comprise means for performing the respective operations of the method 600. The means may be implemented in any suitable form. For example, the means may be implemented in acircuitry or software module. The second apparatus may be implemented as or included in the second apparatus 220 in FIG. 2.

[0355] In some example embodiments, the second apparatus 120 comprises means for transmitting, to a first apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; means for receiving, from the first apparatus, a measurement report transmitted by the first apparatus in response to at least one event in the list of events being detected for a candidate cell of the list of candidate cells; means for transmitting, to the first apparatus, a switch command of the candidate cell in response to receiving the measurement report; and means for determining a cell switch delay based on at least one of the following: whether a candidate cell configuration of the candidate cell has been pre-processed by the first apparatus, a starting time point for pre-processing the candidate cell configuration, or an ending time point for pre-processing the candidate cell configuration.

[0356] In some example embodiments, the second apparatus 120 receives, from the first apparatus 110, a message comprising at least one of the following: an indication whether the candidate cell configuration of the candidate cell has been pre-processed by the first apparatus, an indication that the first apparatus is to pre-process the candidate cell configuration, an indication of a starting time point for pre-processing the candidate cell configuration, an indication of an ending time point for pre-processing the candidate cell configuration; and determines the cell switch delay based on the message.

[0357] In some example embodiments, the second apparatus 120 further comprises: means for determining that pre-processing the candidate cell configuration has been performed by the first apparatus based on that a time length between a starting time point for pre-processing and the cell switch command is larger than or equal to a threshold; or means for determining that pre-processing the candidate cell configuration has not been performed by the first apparatus based on that the time length between the starting time point and the cell switch command is smaller than or equal to a threshold.

[0358] In some example embodiments, the second apparatus 120 further comprises: means for determining that pre-processing the candidate cell configuration has been performed by the first apparatus in response to receiving the measurement report.

[0359] In some example embodiments, the first apparatus starts to pre-process thecandidate cell configuration in response to one of the following: a detection of the at least one of event, a transmission of the measurement report triggered by the at least one event, or a reception of acknowledgement of the measurement report.

[0360] In some example embodiments, the second apparatus 120 further comprises: means for, based on that the early decoding and / or validity check has been performed, setting the first parameter to be a first value; or means for, based on that the early decoding and / or validity check has not been performed, setting the first parameter to be a second value larger than the first value.

[0361] In some example embodiments, the second apparatus 120 further comprises: means for, based on that at least part of the at least one parameter has been applied, setting the second parameter to be a first value; or means for, based on that the at least one parameter has not been applied, setting the second parameter to be a second value larger than the first value.

[0362] In some example embodiments, the second apparatus 120 further comprises: means for receiving, from the first apparatus, capability-related information indicating that the first apparatus supports pre-processing the candidate cell configuration based on detecting the at least one event.

[0363] In some example embodiments, the event -triggered reporting configuration comprises an indication for enabling or disabling pre-processing the candidate cell configuration.

[0364] In some example embodiments, the event -triggered reporting configuration comprises at least one of the following: a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration, or a layer 3 (L3) event-triggered reporting configuration.

[0365] In some example embodiments, the first apparatus comprises a terminal apparatus and the second apparatus 120 comprises a network apparatus.

[0366] In some example embodiments, a first apparatus capable of performing any of the method 700 (for example, the first apparatus 210 in FIG. 2) may comprise means for performing the respective operations of the method 700. 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 firstapparatus 210 in FIG. 2.

[0367] In some example embodiments, the first apparatus 110 comprises means for receiving, from a second apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; means for, based on at least one event in the list of events being detected for a candidate cell of the list of candidate cells, performing preparation comprising time / frequency synchronization for the candidate cell; means for receiving, from the second apparatus, a switch command of the candidate cell transmitted by the second apparatus in response to receiving a measurement report of the candidate cell; and means for determining a switch- related delay based on at least one of the following: whether the time / frequency synchronization for the candidate cell has been performed, a starting time point for performing the time / frequency synchronization for the candidate cell, or an ending time point for performing the time / frequency synchronization for the candidate cell.

[0368] In some example embodiments, the first apparatus 110 starts to perform the time / frequency synchronization in response to one of the following: a detection of the at least one of event, a transmission of a measurement report triggered by the at least one event, or a reception of acknowledgement of the measurement report.

[0369] In some example embodiments, the switch-related delay comprises at least one of the following: a cell switch delay, a physical downlink control channel (PDCCH) ordered random access channel (RACH) delay, or a transmission configuration indicator (TCI) state activation delay.

[0370] In some example embodiments, the first apparatus 110 further comprises: means for, based on that the time / frequency synchronization has been performed, setting the parameter to be a first value; or means for, based on that the time / frequency synchronization has not been performed, setting the parameter to be a second value larger than the first value.

[0371] In some example embodiments, the parameter comprises at least one of the following: a first parameter for fine time and / or frequency synchronization, or a second parameter for reference signal (RS) processing.

[0372] In some example embodiments, the first apparatus 110 comprises means for performing the time / frequency synchronization in accordance with a determination that:at least one transmission configuration indicator (TCI) state associated with candidate cell is comprised in an activated TCI state list, a reference signal (RS) associated with the candidate cell has a Quasi Co-Location (QCL) relationship with a transmission configuration indicator (TCI) state in an activated TCI state list, wherein a measurement result of the RS triggers the at least one event on the candidate cell, or none of TCI states in the activated TCI state list are associated with the candidate cell.

[0373] In some example embodiments, the first apparatus 110 comprises means for performing the time / frequency synchronization for a pre-determined duration.

[0374] In some example embodiments, the first apparatus 110 transmits, to the second apparatus 120, a message comprising at least one of the following: an indication whether the time / frequency synchronization has been performed by the first apparatus, an indication that the first apparatus is to perform the time / frequency synchronization, an indication of a starting time point for performing the time / frequency synchronization, or an indication of an ending time point for performing the time / frequency synchronization.

[0375] In some example embodiments, the first apparatus 110 further comprises: means for transmitting, to the second apparatus, a measurement report triggered by the at least one event on a condition that the time / frequency synchronization has been performed.

[0376] In some example embodiments, the first apparatus 110 further comprises: means for transmitting, to the second apparatus, capability-related information indicating that the first apparatus supports the preparation comprising the time / frequency synchronization based on detecting the at least one event.

[0377] In some example embodiments, the event-triggered reporting configuration comprises an indication for enabling or disabling performing the preparation comprising the time / frequency synchronization.

[0378] In some example embodiments, the event-triggered reporting configuration comprises at least one of the following: a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration, or a layer 3 (L3) event-triggered reporting configuration.

[0379] In some example embodiments, the first apparatus 110 comprises a terminal apparatus and the second apparatus 120 comprises a network apparatus.

[0380] In some example embodiments, a second apparatus capable of performing anyof the method 800 (for example, the second apparatus 220 in FIG. 2) 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 second apparatus may be implemented as or included in the second apparatus 220 in FIG. 2.

[0381] In some example embodiments, the second apparatus 120 comprises means for transmitting, to a first apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; means for receiving, from the first apparatus, a measurement report transmitted by the first apparatus in response to at least one event in the list of events being detected for a candidate cell of the list of candidate cells; means for transmitting, to the first apparatus, a switch command of the candidate cell in response to receiving the measurement report; and means for determining a switch-related delay based on at least one of the following: whether preparation comprising time / frequency synchronization for the candidate cell has been performed by the first apparatus, a starting time point for performing the time / frequency synchronization for the candidate cell, or an ending time point for performing the time / frequency synchronization for the candidate cell.

[0382] In some example embodiments, the second apparatus 120 receives, from the first apparatus 110, a message comprising at least one of the following: an indication whether the time / frequency synchronization has been performed by the first apparatus, an indication that the first apparatus is to perform the time / frequency synchronization, an indication of a starting time point for performing the time / frequency synchronization, or an indication of an ending time point for performing the time / frequency synchronization.

[0383] In some example embodiments, the second apparatus 120 further comprises: means for determining that the time / frequency synchronization has been performed by the first apparatus based on that a time length between a starting time point for performing the preparation and the cell switch command is larger than or equal to a threshold; or means for determining that the time / frequency synchronization has not been performed by the first apparatus based on that the time length between the starting time point and the cell switch command is smaller than or equal to a threshold.

[0384] In some example embodiments, the second apparatus 120 further comprises: means for determining that the time / frequency synchronization has been performed by thefirst apparatus in response to receiving the measurement report.

[0385] In some example embodiments, the first apparatus starts to perform the time / frequency synchronization in response to one of the following: a detection of the at least one of event, a transmission of the measurement report triggered by the at least one event, or a reception of acknowledgement of the measurement report.

[0386] In some example embodiments, the switch-related delay is determined based at least in part on a parameter, and the first apparatus is further caused to: means for, based on that the time / frequency synchronization has been performed, setting the parameter to be a first value; or means for, based on that the time / frequency synchronization has not been performed, setting the parameter to be a second value larger than the first value.

[0387] In some example embodiments, the parameter comprises at least one of the following: a first parameter for fine time and / or frequency synchronization, or a second parameter for reference signal (RS) processing.

[0388] In some example embodiments, the second apparatus further comprises: means for receiving, from the first apparatus, capability-related information indicating that the first apparatus supports the preparation comprising the time / frequency synchronization based on detecting the at least one event.

[0389] In some example embodiments, the event -triggered reporting configuration comprises an indication for enabling or disabling the preparation comprising the time / frequency synchronization.

[0390] In some example embodiments, the event -triggered reporting configuration comprises at least one of the following: a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration, or a layer 3 (L3) event-triggered reporting configuration.

[0391] In some example embodiments, the first apparatus 110 comprises a terminal apparatus and the second apparatus 120 comprises a network apparatus.

[0392] In some example embodiments, a first apparatus capable of performing any of the method 900 (for example, the first apparatus 210 in FIG. 2) 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 firstapparatus 210 in FIG. 2.

[0393] In some example embodiments, the first apparatus 110 comprises means for receiving, from a second apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; means for, based on at least one event in the list of events being detected for a candidate cell of the list of candidate cells, performing preparation comprising user equipment (UE)-based timing advance (TA) estimation for the candidate cell; means for receiving, from the second apparatus, a switch command of the candidate cell transmitted by the second apparatus in response to receiving a measurement report of the candidate cell; and means for determining a cell switch delay based on at least one of the following: whether the UE-based TA estimation for the candidate cell has been performed, a starting time point for performing the UE-based TA estimation for the candidate cell, or an ending time point for performing the UE-based TA estimation for the candidate cell.

[0394] In some example embodiments, the first apparatus 110 starts to perform the UE- based TA estimation in response to one of the following: a detection of the at least one of event, a transmission of a measurement report triggered by the at least one event, or a reception of acknowledgement of the measurement report.

[0395] In some example embodiments, the first apparatus 110 transmits, to the second apparatus 120, a message comprising at least one of the following: an indication whether the preparation or the UE-based TA estimation has been performed by the first apparatus, an indication that the first apparatus is to perform the preparation or the UE-based TA estimation, an indication of a starting time point for performing the preparation or the UE- based TA estimation, or an indication of an ending time point for performing the preparation or the UE-based TA estimation.

[0396] In some example embodiments, the preparation further comprises pre-processing a candidate cell configuration of the candidate cell.

[0397] In some example embodiments, the first apparatus 110 determines the cell switch delay further based on at least one of the following: whether the candidate cell configuration of the candidate cell has been pre-processed, a starting time point for preprocessing the candidate cell configuration, or an ending time point for pre-processing the candidate cell configuration.

[0398] In some example embodiments, the first apparatus 110 transmits, to the second apparatus, a message comprising at least one of the following: an indication whether the candidate cell configuration of the candidate cell has been pre-processed by the first apparatus, an indication that the first apparatus is to pre-process the candidate cell configuration, an indication of a starting time point for pre-processing the candidate cell configuration, or an indication of an ending time point for pre-processing the candidate cell configuration.

[0399] In some example embodiments, the preparation further comprises time / frequency synchronization.

[0400] In some example embodiments, the first apparatus 110 determines the cell switch delay further based on at least one of the following: whether the time / frequency synchronization for the candidate cell has been performed, a starting time point for performing the time / frequency synchronization for the candidate cell, or an ending time point for performing the time / frequency synchronization for the candidate cell.

[0401] In some example embodiments, the first apparatus 110 transmits, to the second apparatus 120, a message comprising at least one of the following: an indication whether the time / frequency synchronization has been performed by the first apparatus, an indication that the first apparatus is to perform the time / frequency synchronization, an indication of a starting time point for performing the time / frequency synchronization, or an indication of an ending time point for performing the time / frequency synchronization.

[0402] In some example embodiments, the first apparatus 110 further comprises: means for transmitting, to the second apparatus, a measurement report triggered by the at least one event on a condition that the preparation has been performed.

[0403] In some example embodiments, the first apparatus 110 further comprises: means for transmitting, to the second apparatus, capability-related information indicating that the first apparatus supports the preparation based on detecting the at least one event.

[0404] In some example embodiments, the event-triggered reporting configuration comprises an indication for enabling or disabling performing the preparation.

[0405] In some example embodiments, the event-triggered reporting configuration comprises at least one of the following: a layer 1 / layer 2 (L1 / L2) triggered mobility(LTM)-based configuration, or a layer 3 (L3) event-triggered reporting configuration.

[0406] In some example embodiments, the first apparatus 110 comprises a terminal apparatus and the second apparatus 120 comprises a network apparatus.

[0407] In some example embodiments, a second apparatus capable of performing any of the method 1000 (for example, the first apparatus 210 in FIG. 2) 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 second apparatus may be implemented as or included in the second apparatus 220 in FIG. 2.

[0408] In some example embodiments, the second apparatus 120 comprises means for transmitting, to a first apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; means for receiving, from the first apparatus, a measurement report transmitted by the first apparatus in response to at least one event in the list of events being detected for a candidate cell of the list of candidate cells; means for transmitting, to the first apparatus, a switch command of the candidate cell in response to receiving the measurement report; and means for determining a cell switch delay based on at least one of the following: whether preparation comprising user equipment (UE)-based timing advance (TA) estimation for the candidate cell has been performed by the first apparatus, a starting time point for performing the UE -based TA estimation for the candidate cell, or an ending time point for performing the UE-based TA estimation for the candidate cell.

[0409] In some example embodiments, the second apparatus 120 receives, from the first apparatus 110, a message comprising at least one of the following: an indication whether the preparation or the UE-based TA estimation has been performed by the first apparatus, an indication that the first apparatus is to perform the preparation or the UE-based TA estimation, an indication of a starting time point for performing the preparation or the UE- based TA estimation, or an indication of an ending time point for performing the preparation or the UE-based TA estimation.

[0410] In some example embodiments, the preparation further comprises pre-processing a candidate cell configuration of the candidate cell.

[0411] In some example embodiments, the second apparatus 120 determines the cellswitch delay further based on at least one of the following: whether the candidate cell configuration of the candidate cell has been pre-processed, a starting time point for preprocessing the candidate cell configuration, or an ending time point for pre-processing the candidate cell configuration.

[0412] In some example embodiments, the second apparatus 120 transmits, to the second apparatus 120, a message comprising at least one of the following: an indication whether the candidate cell configuration of the candidate cell has been pre-processed by the first apparatus, an indication that the first apparatus is to pre-process the candidate cell configuration, an indication of a starting time point for pre-processing the candidate cell configuration, or an indication of an ending time point for pre-processing the candidate cell configuration.

[0413] In some example embodiments, the preparation further comprises time / frequency synchronization.

[0414] In some example embodiments, the second apparatus 120 determines the cell switch delay further based on at least one of the following: whether the time / frequency synchronization for the candidate cell has been performed, a starting time point for performing the time / frequency synchronization for the candidate cell, or an ending time point for performing the time / frequency synchronization for the candidate cell.

[0415] In some example embodiments, the first apparatus 110 transmits, to the second apparatus 120, a message comprising at least one of the following: an indication whether the time / frequency synchronization has been performed by the first apparatus, an indication that the first apparatus is to perform the time / frequency synchronization, an indication of a starting time point for performing the time / frequency synchronization, or an indication of an ending time point for performing the time / frequency synchronization.

[0416] In some example embodiments, the second apparatus 120 further comprises: means for determining that the preparation has been performed by the first apparatus based on that a time length between a starting time point for performing the preparation and the cell switch command is larger than or equal to a threshold; or means for determining that the preparation has not been performed by the first apparatus based on that the time length between the starting time point and the cell switch command is smaller than or equal to a threshold.

[0417] In some example embodiments, the second apparatus further comprises: means for determining that the preparation has been performed by the first apparatus in response to receiving the measurement report.

[0418] In some example embodiments, the first apparatus starts to perform the UE- based TA estimation in response to one of the following: a detection of the at least one of event, a transmission of the measurement report triggered by the at least one event, or a reception of acknowledgement of the measurement report.

[0419] In some example embodiments, the second apparatus further comprises: means for receiving, from the first apparatus, capability-related information indicating that the first apparatus supports the preparation based on detecting the at least one event.

[0420] In some example embodiments, the event-triggered reporting configuration comprises an indication for enabling or disabling the preparation.

[0421] In some example embodiments, the event -triggered reporting configuration comprises at least one of the following: a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration, or a layer 3 (L3) event-triggered reporting configuration.

[0422] In some example embodiments, the first apparatus 110 comprises a terminal apparatus and the second apparatus 120 comprises a network apparatus.

[0423] In some example embodiments, a first apparatus capable of performing any of the method 1100 (for example, the first apparatus 210 in FIG. 2) 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 210 in FIG. 2.

[0424] In some example embodiments, the first apparatus 110 comprises means for receiving, from a second apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; means for determining a plurality of candidate cells, at least one event in the list of events being detected for each of the plurality of candidate cells; means for determining at least one candidate cell from the plurality of candidate cells to perform preparation of cell switch based on at least one of the following: a plurality of signal qualities of the plurality ofcandidate cells, a plurality of time points at which the plurality of candidate cell fulfill respective reporting conditions, a plurality of events detected on the plurality of candidate cell, a priority order of the plurality of candidate cells, a plurality of switch types of the plurality of candidate cells, a plurality of switch states of the plurality of candidate cells, or a plurality of cell identities of the plurality of candidate cells; and means for performing the cell switch preparation on at least one candidate cell.

[0425] In some example embodiments, the preparation of cell switch comprises at least one of the following: pre-processing a candidate cell configuration of the candidate cell, time / frequency synchronization, or user equipment (UE)-based timing advance (TA) estimation.

[0426] In some example embodiments, the first apparatus 110 starts to perform the preparation of cell switch in response to one of the following: a detection of the at least one of event, a transmission of a measurement report triggered by the at least one event, or a reception of acknowledgement of the measurement report.

[0427] In some example embodiments, the signal quality comprises at least one of the following: a signal quality associated with a specific event, a reference signal receiving power (RSRP), an interference plus noise ratio (SINR), a received signal strength indication (RSSI), or a reference signal receiving quality (RSRQ).

[0428] In some example embodiments, the switch type comprises at least one of the following: an intra-the next Generation Node B (gNB) switch, an inter-gNB switch, an intra-centralized unit (CU) switch, or an inter-CU switch.

[0429] In some example embodiments, the switch state is associated with a completion state of at least one of the following: pre-processing a candidate cell configuration of the candidate cell, a time / frequency synchronization, a user equipment (UE)-based timing advance (TA) estimation, a transmission configuration indicator (TCI) state activation, a random access channel (RACH)-based TA acquisition, or a physical downlink control channel (PDCCH) ordered RACH preamble transmission.

[0430] In some example embodiments, the event -triggered reporting configuration comprises at least one of the following: an indication for enabling or disabling performing the preparation, an event priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, a candidate cell priority order usedby the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, a switch type priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, or at least one rule used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells.

[0431] In some example embodiments, the first apparatus 110 transmits, to the second apparatus, capability-related information indicating at least of the following: the first apparatus supporting the preparation, or a maximum number of candidate cells on which the first apparatus is capable of performing preparation.

[0432] In some example embodiments, the event-triggered reporting configuration comprises at least one of the following: a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration, or a layer 3 (L3) event-triggered reporting configuration.

[0433] In some example embodiments, the first apparatus 110 comprises a terminal apparatus and the second apparatus comprises a network apparatus.

[0434] In some example embodiments, a second apparatus capable of performing any of the method 1200 (for example, the first apparatus 210 in FIG. 2) may comprise means for performing the respective operations of the method 1200. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the second apparatus 220 in FIG. 2.

[0435] In some example embodiments, the second apparatus 120 comprises means for generating, an event -triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells, wherein the LTM-based configuration comprises at least one of the following: an indication for enabling or disabling performing preparation of cell switch at the first apparatus, an event priority order used by the first apparatus to determine at least one candidate cell to perform the preparation of cell switch from a plurality of candidate cells, a candidate cell priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, a switch type priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, or at least one rule used by the first apparatus to determine the at least one candidate cell from the plurality ofcandidate cells; and means for transmitting the event-triggered reporting configuration to a first apparatus.

[0436] In some example embodiments, the preparation of cell switch comprises at least one of the following: pre-processing a candidate cell configuration of the candidate cell time / frequency synchronization, or user equipment (UE)-based timing advance (TA) estimation.

[0437] In some example embodiments, the first apparatus 110 starts to perform the preparation of cell switch in response to one of the following: a detection of the at least one of event, a transmission of a measurement report triggered by the at least one event, or a reception of acknowledgement of the measurement report.

[0438] In some example embodiments, the switch type comprises at least one of the following: an intra-the next Generation Node B (gNB) switch, an inter-gNB switch, an intra-centralized unit (CU) switch, or an inter-CU switch.

[0439] In some example embodiments, the switch state is associated with a completion state of at least one of the following: pre-processing a candidate cell configuration of the candidate cell, a time / frequency synchronization, a user equipment (UE)-based timing advance (TA) estimation, a transmission configuration indicator (TCI) state activation, a random access channel (RACH)-based TA acquisition, or a physical downlink control channel (PDCCH) ordered RACH preamble transmission.

[0440] In some example embodiments, the first apparatus 110 transmits, to the second apparatus, capability-related information indicating at least of the following: the first apparatus supporting the preparation, or a maximum number of candidate cells on which the first apparatus is capable of performing preparation.

[0441] In some example embodiments, the event -triggered reporting configuration comprises at least one of the following: a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration, or a layer 3 (L3) event-triggered reporting configuration.

[0442] In some example embodiments, the first apparatus 110 comprises a terminal apparatus and the second apparatus 120 comprises a network apparatus.

[0443] In some example embodiments, a first apparatus capable of performing any of the method 1300 (for example, the first apparatus 210 in FIG. 2) may comprise means forperforming the respective operations of the method 1300. 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 210 in FIG. 2.

[0444] In some example embodiments, the first apparatus comprises means for receiving, from a second apparatus, a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)- based configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; means for performing, based on the LTM-based configuration, measurements on the list of candidate cells; means for determining, based on measurement results of the measurements, at least one event being detected for a candidate cell of the list of candidate cells; means for suspending a transmission of a layer 1 (LI) measurement report triggered by the at least one event until a reporting criterion is fulfilled, wherein the reporting criterion is determined to be fulfilled at least based on a preparation of cell switch has been performed.

[0445] In some example embodiments, the preparation of cell switch comprises at least one of the following: pre-processing a candidate cell configuration of the candidate cell, time / frequency synchronization, user equipment (UE)-based timing advance (TA) estimation, a transmission configuration indicator (TCI) state activation, a random access channel (RACH)-based TA acquisition, or a physical downlink control channel (PDCCH) ordered RACH preamble transmission.

[0446] In some example embodiments, the first apparatus 110 starts to perform the preparation of cell switch in response to one of the following: a detection of the at least one of event, a transmission of the LI measurement report triggered by the at least one event, or a reception of acknowledgement of the LI measurement report.

[0447] In some example embodiments, the measurement comprises at least one of the following: an LI signal quality associated with a specific event measurement, an LI reference signal receiving power (RSRP) measurement, an LI signal to interference plus noise ratio (SINR) measurement, an LI received signal strength indication (RSSI) measurement, or an LI reference signal receiving quality (RSRQ) measurement.

[0448] In some example embodiments, the first apparatus 110 comprises a terminal apparatus and the second apparatus 120 comprises a network apparatus.

[0449] In some example embodiments, a second apparatus capable of performing any of the method 1400 (for example, the first apparatus 210 in FIG. 2) may comprise means for performing the respective operations of the method 1400. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the second apparatus 220 in FIG. 2.

[0450] In some example embodiments, the second apparatus comprises means for transmitting, to a first apparatus, a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration indicating and a list of candidate cells and a list of events configured for the list of candidate cells; and means for receiving, from the first apparatus, a layer 1 (LI) measurement report triggered by at least one event in the list of events being detected for a candidate cell of the list of candidate cells, wherein the LI measurement report is transmitted by the first apparatus in response to a reporting criterion being fulfilled, wherein the reporting criterion is determined to be fulfilled at least based on a preparation of cell switch has been performed.

[0451] In some example embodiments, the preparation of cell switch comprises at least one of the following: pre-processing a candidate cell configuration of the candidate cell, time / frequency synchronization, user equipment (UE)-based timing advance (TA) estimation, a transmission configuration indicator (TCI) state activation, a random access channel (RACH)-based TA acquisition, or a physical downlink control channel (PDCCH) ordered RACH preamble transmission.

[0452] In some example embodiments, the preparation of cell switch is performed by the first apparatus in response to one of the following: a detection of the at least one of event, a transmission of the LI measurement report triggered by the at least one event, or a reception of acknowledgement of the LI measurement report.

[0453] In some example embodiments, the second apparatus 120 determines that the preparation has been performed by the first apparatus in response to receiving the LI measurement report.

[0454] In some example embodiments, the second apparatus 120 determines a cell switch delay by assuming the preparation of cell switch has been performed by the first apparatus.

[0455] In some example embodiments, the measurement comprises at least one of the following: an LI signal quality associated with a specific event measurement, an LI reference signal receiving power (RSRP) measurement, an LI signal to interference plus noise ratio (SINR) measurement, an LI received signal strength indication (RSSI) measurement, or an LI reference signal receiving quality (RSRQ) measurement.

[0456] In some example embodiments, the first apparatus 110 comprises a terminal apparatus and the second apparatus 120 comprises a network apparatus.

[0457] FIG. 15 is a simplified block diagram of a device 1500 that is suitable for implementing example embodiments of the present disclosure. The device 1500 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 1500 includes one or more processors 1510, one or more memories 1520 coupled to the processor 1510, and one or more communication modules 1540 coupled to the processor 1510.

[0458] The communication module 1540 is for bidirectional communications. The communication module 1540 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 1540 may include at least one antenna.

[0459] The processor 1510 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 1500 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.

[0460] The memory 1520 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) 1524, 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-accessmemory (RAM) 1522 and other volatile memories that will not last in the power-down duration.

[0461] A computer program 1530 includes computer executable instructions that are executed by the associated processor 1510. The instructions of the program 1530 may include instructions for performing operations / acts of some example embodiments of the present disclosure. The program 1530 may be stored in the memory, e.g., the ROM 1524. The processor 1510 may perform any suitable actions and processing by loading the program 1530 into the RAM 1522.

[0462] The example embodiments of the present disclosure may be implemented by means of the program 1530 so that the device 1500 may perform any process of the disclosure as discussed with reference to FIG. 2 to FIG. 14. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0463] In some example embodiments, the program 1530 may be tangibly contained in a computer readable medium which may be included in the device 1500 (such as in the memory 1520) or other storage devices that are accessible by the device 1500. The device 1500 may load the program 1530 from the computer readable medium to the RAM 1522 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).

[0464] FIG. 16 shows an example of the computer readable medium 1600 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 1600 has the program 1530 stored thereon.

[0465] 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 pictorialrepresentations, 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.

[0466] 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.

[0467] 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.

[0468] 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.

[0469] 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 specificexamples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random-access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0470] 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.

[0471] 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

1. I / We Claim:

1. A first apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus to: receive, from a second apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; determine a plurality of candidate cells, at least one event in the list of events being detected for each of the plurality of candidate cells; determine at least one candidate cell from the plurality of candidate cells to perform preparation of cell switch based on at least one of the following: a plurality of signal qualities of the plurality of candidate cells, a plurality of time points at which the plurality of candidate cell fulfill respective reporting conditions, a plurality of events detected on the plurality of candidate cell, a priority order of the plurality of candidate cells, a plurality of switch types of the plurality of candidate cells, a plurality of switch states of the plurality of candidate cells, or a plurality of cell identities of the plurality of candidate cells; and perform the cell switch preparation on at least one candidate cell.

2. The first apparatus of claim 1, wherein the preparation of cell switch comprises at least one of the following: pre-processing a candidate cell configuration of the candidate cell, time / frequency synchronization, or user equipment (UE)-based timing advance (TA) estimation.

3. The first apparatus of claim 1 or 2, wherein the first apparatus is further caused to start to perform the preparation of cell switch in response to one of the following: a detection of the at least one of event, a transmission of a measurement report triggered by the at least one event, ora reception of acknowledgement of the measurement report.

4. The first apparatus of any of claims 1 to 3, wherein the signal quality comprises at least one of the following: a signal quality associated with a specific event, a reference signal receiving power (RSRP), a signal to interference plus noise ratio (SINR), a received signal strength indication (RS SI), or a reference signal receiving quality (RSRQ).

5. The first apparatus of any of claims 1 to 4, wherein the switch type comprises at least one of the following: an intra-the next Generation Node B (gNB) switch, an inter-gNB switch, an intra-centralized unit (CU) switch, or an inter-CU switch.

6. The first apparatus of any of claim 1 to 5, wherein the switch state is associated with a completion state of at least one of the following: pre-processing a candidate cell configuration of the candidate cell, a time / frequency synchronization, a user equipment (UE)-based timing advance (TA) estimation, a transmission configuration indicator (TCI) state activation, a random access channel (RACH)-based TA acquisition, or a physical downlink control channel (PDCCH) ordered RACH preamble transmission.

7. The first apparatus of any of claims 1 to 6, wherein the event-triggered reporting configuration comprises at least one of the following: an indication for enabling or disabling performing the preparation, an event priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, a candidate cell priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells,a switch type priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, or at least one rule used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells.

8. The first apparatus of any of claims 1 to 7, wherein the first apparatus is further caused to transmit, to the second apparatus, capability-related information indicating at least of the following: the first apparatus supporting the preparation, or a maximum number of candidate cells on which the first apparatus is capable of performing preparation.

9. The first apparatus of any of claims 1 to 8, wherein the event-triggered reporting configuration comprises at least one of the following: a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration, or a layer 3 (L3) event-triggered reporting configuration.

10. The first apparatus of any of claims 1 to 9, wherein the first apparatus comprises a terminal apparatus and the second apparatus comprises a network apparatus.

11. A second apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus to: generate, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells, wherein the LTM-based configuration comprises at least one of the following: an indication for enabling or disabling performing preparation of cell switch at the first apparatus, an event priority order used by the first apparatus to determine at least one candidate cell to perform the preparation of cell switch from a plurality of candidate cells, a candidate cell priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells,a switch type priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, or at least one rule used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells; and transmit the event-triggered reporting configuration to a first apparatus.

12. The second apparatus of claim 11, wherein the preparation of cell switch comprises at least one of the following: pre-processing a candidate cell configuration of the candidate cell time / frequency synchronization, or user equipment (UE)-based timing advance (TA) estimation.

13. The second apparatus of claim 11 or 12, wherein the first apparatus is further caused to start to perform the preparation of cell switch in response to one of the following: a detection of the at least one of event, a transmission of a measurement report triggered by the at least one event, or a reception of acknowledgement of the measurement report.

14. The second apparatus of any of claims 11 to 13, wherein the switch type comprises at least one of the following: an intra-the next Generation Node B (gNB) switch, an inter-gNB switch, an intra-centralized unit (CU) switch, or an inter-CU switch.

15. The second apparatus of any of claim 11 to 14, wherein the switch state is associated with a completion state of at least one of the following: pre-processing a candidate cell configuration of the candidate cell, a time / frequency synchronization, a user equipment (UE)-based timing advance (TA) estimation, a transmission configuration indicator (TCI) state activation, a random access channel (RACH)-based TA acquisition, or a physical downlink control channel (PDCCH) ordered RACH preamble transmission.

16. The second apparatus of any of claims 11 to 15, wherein the first apparatus is further caused to transmit, to the second apparatus, capability -related information indicating at least of the following: the first apparatus supporting the preparation, or a maximum number of candidate cells on which the first apparatus is capable of performing preparation.

17. The second apparatus of any of claims 11 to 16, wherein the event-triggered reporting configuration comprises at least one of the following: a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration, or a layer 3 (L3) event-triggered reporting configuration.

18. The second apparatus of any of claims 11 to 17, wherein the first apparatus comprises a terminal apparatus and the second apparatus comprises a network apparatus.

19. A method comprising: receiving, from a second apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; determining a plurality of candidate cells, at least one event in the list of events being detected for each of the plurality of candidate cells; determining at least one candidate cell from the plurality of candidate cells to perform preparation of cell switch based on at least one of the following: a plurality of signal qualities of the plurality of candidate cells, a plurality of time points at which the plurality of candidate cell fulfill respective reporting conditions, a plurality of events detected on the plurality of candidate cell, a priority order of the plurality of candidate cells, a plurality of switch types of the plurality of candidate cells, a plurality of switch states of the plurality of candidate cells, or a plurality of cell identities of the plurality of candidate cells; andperforming the cell switch preparation on at least one candidate cell.

20. A method comprising: generating, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells, wherein the LTM-based configuration comprises at least one of the following: an indication for enabling or disabling performing preparation of cell switch at the first apparatus, an event priority order used by the first apparatus to determine at least one candidate cell to perform the preparation of cell switch from a plurality of candidate cells, a candidate cell priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, a switch type priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, or at least one rule used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells; and transmitting the event-triggered reporting configuration to a first apparatus.

21. A first apparatus comprising: means for receiving, from a second apparatus, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells; means for determining a plurality of candidate cells, at least one event in the list of events being detected for each of the plurality of candidate cells; means for determining at least one candidate cell from the plurality of candidate cells to perform preparation of cell switch based on at least one of the following: a plurality of signal qualities of the plurality of candidate cells, a plurality of time points at which the plurality of candidate cell fulfill respective reporting conditions, a plurality of events detected on the plurality of candidate cell, a priority order of the plurality of candidate cells, a plurality of switch types of the plurality of candidate cells, a plurality of switch states of the plurality of candidate cells, ora plurality of cell identities of the plurality of candidate cells; and means for performing the cell switch preparation on at least one candidate cell.

22. A second apparatus comprising: means for generating, an event-triggered reporting configuration indicating a list of candidate cells and a list of events configured for the list of candidate cells, wherein the LTM-based configuration comprises at least one of the following: an indication for enabling or disabling performing preparation of cell switch at the first apparatus, an event priority order used by the first apparatus to determine at least one candidate cell to perform the preparation of cell switch from a plurality of candidate cells, a candidate cell priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, a switch type priority order used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells, or at least one rule used by the first apparatus to determine the at least one candidate cell from the plurality of candidate cells; and means for transmitting the event-triggered reporting configuration to a first apparatus.

23. A computer readable medium comprising instructions stored thereon for causing an apparatus at least to perform the method of claim 19 or 20.

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