Event-triggering layer 1 / layer 2-triggered mobility reporting for inter-frequency load balancing layer 1 / layer 2-triggered mobility cell switching

Abstract

A communication device can be configured to provide event-triggering layer 1 / layer 2- triggered mobility (LTM) reporting for inter-frequency load balancing LTM cell switching The communication device can determine (840) that a triggering condition is met based on a measurement associated with a LTM candidate cell. Responsive to determining that the triggering condition is met, the communication device can transmit (850) a LTM lower layer measurement report.

Description

EVENT-TRIGGERING LAYER 1 / LAYER 2-TRIGGERED MOBILITY REPORTING FOR INTER-FREQUENCY LOAD BALANCING LAYER 1 / LAYER 2-TRIGGERED MOBILITY CELL SWITCHINGTECHNICAL FIELD

[0001] The present disclosure is related to wireless communication systems and more particularly to event-triggering layer 1 / layer 2-triggered mobility (LTM) reporting for interfrequency load balancing LTM cell switching.BACKGROUND

[0002] FIG. 1 illustrates an example of a new radio (NR) network (e.g., a 5th Generation (5G) network) including a 5G core (5GC) network 130, network nodes 120a-b (e.g., 5G base station (gNB)), multiple communication devices 110 (also referred to as user equipment (“UE”)).

[0003] Layer 1 (“Ll”) / Layer 2 (“L2”)-Triggered Mobility (“LTM”) can be defined as a Primary Cell (“PCell”) (or primary secondary cell (“PSCell”)) cell switch procedure, consequently with Cell Group change (e.g., Master Cell Group (MCG) or Secondary Cell Group (SCG) that the network triggers via media access control (MAC) Control Element (CE) based on LI measurements. In that procedure, a gNB receives the LI measurement report(s) from the UE, and on their basis the gNB changes UE’s serving cell by a cell switch command signaled via a MAC CE. The cell switch command indicates an LTM candidate cell configuration that the gNB previously prepared and provided to the UE through RRC signaling. Then the UE switches to the target cell according to the cell switch command.

[0004] When configured by the network, it is possible to activate Transmission Configuration Indicator (TCI) states of one or multiple cells that are different from the current serving cell, which may be called LTM candidate cells. For instance, the TCI states of the LTM candidate cells can be activated in advance before any of those cells become the serving cell (e.g., by reception of a MAC CE indicating an LTM candidate and a TCI state of the indicated LTM candidate). This allows the UE to be downlink (DL) synchronized with those indicated cells, thereby facilitating a faster cell switch to one of those cells when cell switch is triggered.

[0005] FIG. 2 illustrates an example of an overall procedure for LTM.

[0006] At block 210, the UE sends a MeasurementReport message to the gNB. The gNB decides to configure LTM and initiates candidate cell(s) preparation.

[0007] At block 220, the gNB transmits an RRCReconfiguration message to the UE including the LTM candidate cell configurations of one or multiple candidate cells.

[0008] At block 230, the UE stores the LTM candidate cell configurations and transmits an RRCReconfigurationComplete message to the gNB.

[0009] At block 240a, the UE performs DL synchronization with the candidate cell(s) before receiving the cell switch command.

[0010] At block 240b, the UE performs UL synchronization with the candidate cell(s) before receiving the cell switch command.

[0011] At block 250, the UE performs LI measurements on the configured candidate cell(s) and transmits LI measurement reports to the gNB. LI measurement should be performed as long as RRC reconfiguration (at block 220) is applicable.

[0012] At block 260, the gNB decides to execute cell switch to a target cell and transmits a MAC CE triggering cell switch by including the candidate configuration index of the target cell. The UE switches to the target cell and applies the configuration indicated by candidate configuration index.

[0013] At block 270, the UE performs the random access procedure towards the target cell, if UE does not have valid Timing Advance (“TA”) of the target cell. The UE performs Contention Free Random Access (“CFRA”) if the LTM cell switch command MAC CE contains information for CFRA.

[0014] At block 280, the UE completes the LTM cell switch procedure by sending RRCReconfigurationComplete message to target cell. If the UE has performed a RA procedure (at block 270) the UE considers that LTM cell switch execution is successfully completed when the random access procedure is successfully completed. For RACH-less LTM, the UE considers that LTM cell switch execution is successfully completed when the UE determines that the network has successfully received its first UL data. The UE determines successful reception of its first UL data by receiving a physical downlink control channel (PDCCH) addressing the UE’s cell radio network temporary identifier (C-RNTI) in the target cell, which schedules a new transmission following the first UL data. The PDCCH carries either a DL assignment or an UL grant addressing the same hybrid automatic repeat request (HARQ) process as the first UL data.SUMMARY

[0015] According to some embodiments, a method of operating a communication device is provided. The method includes determining that a triggering condition is met based on a measurement associated with a layer 1 / layer 2-triggered mobility, LTM, candidate cell. The method further includes, responsive to determining that the triggering condition is met, transmitting a LTM lower layer measurement report.

[0016] According to other embodiments, a method of operating a network node is provided. The method includes transmitting an indication of configuration information to a communication device, the configuration information configuring the communication device to transmit a layer 1 / layer 2-triggered mobility, LTM, lower layer report in response to fulfillment of a triggering condition, the triggering condition being based on comparing a measurement to a threshold value, the measurement being associated with a LTM candidate cell. The method further includes receiving the LTM lower layer measurement report from the communication device.

[0017] According to other embodiments, a communication device, a network node, a computer program, computer program product, non-transitory computer readable medium, host, or system is provided to perform one of the above methods.

[0018] Certain embodiments may provide one or more of the following technical advantages. In some embodiments, the innovations provide savings in terms of UE power consumption and UL resources on the network side when the UE needs to assist the network to perform inter-frequency LTM Cell Switch procedures, because unnecessary transmissions, as in periodic reports, would not be performed when the UE only transmits the LTM lower layer report when the condition is fulfilled.

[0019] In additional or alternative embodiments, the innovations enable the UE to perform LTM related measurements (lower layer measurements for LTM candidate cell(s)) to assist the network to take timely inter-frequency LTM Cell Switch decisions, when the PCell is getting too bad to maintain the connection to an acceptable level (PCell worse than absolute threshold) and, at the same time, there is a configured LTM candidate cell in another SSB frequency (different than SSB frequency of the PCell) which is a good candidate (i.e. inter-frequency LTM candidate cell better than an absolute threshold).

[0020] In additional or alternative embodiments, the LTM lower layer report indicates to the network that while the PCell frequency is not good enough, there is another frequency which is good enough. Assuming there was no LTM lower report indicating that there was an LTM candidate cell in the PCell’ s SSB frequency offset better than the PCell, the indication from the proposed LTM report based on the proposed triggering condition is an indication sent by the UE to the network that there is a better frequency to connect to instead of the PCell’ s frequency.

[0021] In additional or alternative embodiments, the proposed report, based on the proposed triggering condition, is to enable the network to pre-activate a TCI state of an inter-frequency LTM candidate cell, which may be critical to enable a fast inter-frequency LTM Cell Switch. The reason is that the delay to synchronize with an inter-frequency neighbour, during an interfrequency LTM Cell Switch, is longer. So, it becomes critical to make sure the UE is DL synchronized with an LTM Candidate cell before an inter-frequency LTM Cell Switch. Thus,the LTM lower layer report, based on the proposed triggering condition(s), enables the UE to get a command to activate a TCI state of an inter-frequency LTM candidate cell, before the UE receives the LTM Cell Switch command.

[0022] Another benefit of the proposed report, based on the proposed triggering condition, is to enable the network to trigger an Early Uplink sync procedure, in which the UE receives a PDCCH order to trigger a random access preamble which enables the network to calculate a timing advance value (to be included in the LTM Cell Switch command). That is also critical to enable a fast inter-frequency LTM Cell Switch.BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are included to provide a further understanding of the disclosure and are incorporated in and constitute a part of this application, illustrate certain non-limiting embodiments of inventive concepts. In the drawings:

[0024] FIG. l is a schematic diagram illustrating an example of a 5thgeneration (“5G”) network;

[0025] FIG. 2 is a signal flow diagram illustrating an example of a LTM procedure;

[0026] FIG. 3 is a signal flow diagram illustrating an example of LTM lower layer reporting in accordance with some embodiments;

[0027] FIG. 4 is a graph illustrating examples of triggering conditions for LTM reporting;

[0028] FIG. 5 is a signal flow diagram illustrating an example of different responses the UE may receive when it triggers a lower layer LTM report;

[0029] FIG. 6 is a table illustrating an example of a mapping order of CSI fields of one report for SSBRI / RSRP reporting for LTM in accordance with some embodiments;

[0030] FIG. 7 is a table illustrating an example of a bitwidth for SSBRI, RSRP, or differential RSRP to be included in an LTM CSI measurement report in accordance with some embodiments;

[0031] FIG. 8 is a flow chart illustrating an example of operations performed by a communication device in accordance with some embodiments;

[0032] FIG. 9 is a flow chart illustrating an example of operations performed by a communication device in accordance with some embodiments;

[0033] FIG. 10 is a block diagram illustrating an example of a communications network architecture with a CU / DU split in accordance with some embodiments;

[0034] FIG. 11 is a signal flow diagram illustrating an example of interactions between a UE, S-DU, CU, and a C-DU for a load balancing triggered inter-frequency LTM cell switch in accordance with some embodiments;

[0035] FIG. 12 is a block diagram of a communication system in accordance with some embodiments;

[0036] FIG. 13 is a block diagram of a user equipment in accordance with some embodiments;

[0037] FIG. 14 is a block diagram of a network node in accordance with some embodiments; and

[0038] FIG. 15 is a block diagram of a virtualization environment in accordance with some embodiments.DETAILED DESCRIPTION

[0039] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art, in which examples of embodiments of inventive concepts are shown. Inventive concepts may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of present inventive concepts to those skilled in the art. It should also be noted that these embodiments are not mutually exclusive. Components from one embodiment may be tacitly assumed to be present / used in another embodiment.

[0040] Layer 1 / Layer 2-triggered mobility (LTM) was introduced in Rel-18 and can offer improvements in handover latency and interruption time compared to Layer 3 based mobility. However, LTM as introduced in Rel-18 also has a number of limitations compared to Layer 3 mobility. The Rel-19 work item aims to remove a number of these limitations. Layer 3 mobility uses layer 3 measurement reporting which supports user equipment (UE) evaluated events for triggering of measurement reports and reduces signaling overhead compared to periodic measurement reporting. Such event triggering is not supported by the LI measurements that are used for LTM mobility.

[0041] Layer 1 (LI) measurements for LTM procedures are limited to synchronization signal block (SSB) measurements. Expanding LI measurements to include a channel state information reference signal (CSLRS) can address this limitation and can be expected to enable greater throughput on the target cell immediately after cell switch.

[0042] There currently exist certain challenges. To assist the network to trigger an LTM Cell Switch, the UE can be configured to transmit LI measurement (LTM lower layer reports) including lower layer measurements on beams (e.g., SSBs) of one or more LTM candidate cells. Thanks to these reports, the network determines the LTM candidate cell and the beam (e.g.,corresponding transmission configuration indication (TCI) state identity) to indicate in the LTM Cell Switch command.

[0043] In the LTM functionality specified in Rel-18, LTM lower layer reports are configured in an LTM reporting configuration (LTM-CSI-ReportConfig IE) as periodic, semi- persistent on physical uplink control channel (PUCCH), semi-persistent on physical uplink shared channel (PUSCH), or aperiodic.

[0044] However, periodic reports consume a significant amount of unnecessary Uplink (UL) resources and makes the UE to waste a lot of energy for reporting measurements periodically, while in fact, the network only needs to know these measurements when the UE is close to a situation in which an LTM cell Switch is to be triggered.

[0045] Other types of reports, e.g., aperiodic reports, rely on requests from the network. It is not always simple to figure out the exact timing in which these reports are to be requested, especially when there is no UL data to be scheduled for the UE.

[0046] FIG. 3 illustrates an example of problems with LTM lower layer periodic reports. In some examples, LTM lower layer measurement reports are expected to assist the network to trigger inter-frequency LTM Cell Switches due to Load Balancing i.e. when the strongest cell the UE is connected to is overloaded (e.g., has too many connected UE(s) and / or has very high traffic demands). To assist the network to take mobility load balancing decisions, the network needs to understand when a neighbour frequency (e.g., a cell in a neighbour frequency) for which the load is lower than the UE’s current serving frequency provides good enough coverage. This considers that LTM CSI resource configuration(s) may include LTM candidate cell(s) which are intra-frequency neighbors and LTM candidate cell(s) which are inter-frequency neighbors.

[0047] Various embodiments herein address some of these challenges by having a UE transmit an LTM lower layer report upon fulfillment of a triggering condition as indicated in FIGS. 4-5.

[0048] In some embodiments, a UE transmits an LTM lower layer report upon fulfillment of a triggering condition, wherein the triggering condition consists of a measurement associated to an inter-frequency LTM candidate cell becomes better than absolute threshold.

[0049] In some examples, UE triggering of a lower layer report when the “best” beam (or RS) of an inter-frequency LTM candidate cell (e.g., highest LI RSRP) becomes better than absolute threshold.

[0050] In additional or alternative examples, UE triggering of a lower layer report when the cell quality (e.g., cell based RSRP) of an inter-frequency LTM candidate cell, in a different frequency as the serving cell, becomes better than absolute threshold.

[0051] In some examples, in response to the LTM lower layer report, the UE receives an LTM Cell Switch Command (e.g., LTM Cell Switch Command MAC Control Element - CE) indicating the LTM Candidate Cell (e.g., Target Configuration ID associated to an LTM candidate ID) which is an inter-frequency neighbour (e.g., in a different SSB frequency than the UE’s serving cell), and a TCI state (e.g., TCI State ID) which is to be activated in the LTM Candidate Cell which becomes the target cell. The indicated TCI state to be activate in the LTM Candidate Cell (which is an inter-frequency neighbour) in the LTM Cell Switch is associated to one of the SSBs indicated in the LTM lower layer report, whose first measurement has triggered the report. In one embodiment, the association between that reported SSB and the indicated TCI state is that the SSB is configured as Quasi-Co-Location (QCL) source of the indicated TCI State. Notice that the inter-frequency LTM Cell Switch does not need to be triggered based on the quality of the PCell, since this is triggered by the network based on the load situation (e.g., traffic demands, number of connected UE(s)) on the PCell (and the PCell’ s frequency) compared to the load situation (e.g., traffic demands, number of connected UE(s)) in the frequency of the LTM Candidate Cell indicated in the LTM Cell Switch Command.

[0052] In additional or alternative examples, before receiving the LTM Cell Switch, in response to the LTM layer report, the UE receives a TCI activation command for an LTM Candidate Cell (e.g., Candidate Cell TCI States Activation / D eactivation MAC CE) indicating the LTM Candidate Cell (e.g., Target Configuration ID associated to an LTM candidate ID) which is an inter-frequency neighbour (e.g., in a different SSB frequency than the UE’s serving cell), and a TCI state (e.g., TCI State ID) which is to be pre-activated in the LTM Candidate Cell. This may be a preparation for an inter-frequency LTM Cell Switch triggered by load balancing at the network i.e. that does not need to be triggered based on the quality of the PCell, since this is triggered by the network based on the load situation (e.g., traffic demands, number of connected UE(s)) on the PCell (and the PCell’ s frequency) compared to the load situation (e.g., traffic demands, number of connected UE(s)) in the frequency of the LTM Candidate Cell indicated in the TCI activation command for an LTM Candidate Cell (e.g., Candidate Cell TCI States Activation / Deactivation MAC CE).

[0053] In additional or alternative examples, before receiving the LTM Cell Switch, and possibly after the TCI activation command for an LTM Candidate Cell, the UE receives a command for triggering an Early Uplink sync procedure (e.g., Physical Downlink control Channel - PDCCH order), indicating an LTM Candidate Cell (which is an inter-frequency neighbour cell) and a Reference Signal (e.g., SSB identifier) based on which the UE transmits a random access preamble to the LTM Candidate Cell. This may be a preparation for an inter-frequency LTM Cell Switch triggered by load balancing at the network i.e. that does not need to be triggered based on the quality of the PCell.

[0054] The LTM lower layer report may include multiple LTM candidate cell(s), in one or more SSB frequencies: the network selects one of the SSB frequencies and one of the LTM candidate cells, for including an associated indication in the LTM Cell Switch command, and / or the TCI activation command for an LTM Candidate Cell (e.g., Candidate Cell TCI States Activation / Deactivation MAC CE) and / or command for triggering an Early Uplink sync procedure (e.g., PDCCH order).

[0055] Various embodiments herein refer to a measurement of a beam. In general terms, measurement of a beam may correspond to a measurement of a Reference Signal (RS) and / or Synchronization Signal (SS), such as a Synchronization Signal Block (SSB) or Channel State Information - RS (CSLRS), or Mobility Reference Signal (MRS). In that context, a beam may be interpreted as a spatial direction (of filter) which the RS or SS is being transmitted.

[0056] In some embodiments, the beam is associated to an activated TCI sate. The beam being associated with the activated TCI state corresponds to an RS (or SS) transmitted in the beam, e.g., indicated by an SSB index and / or CSLRS resource identifier, being configured as Quasi-Co-Location (QCL) source of the activated TCI state of the candidate cell.

[0057] Embodiments herein refer to the term “L1 / L2 based inter-cell mobility,” though it interchangeably also uses the terms L1 / L2 mobility, Ll-mobility, LI based mobility, L1 / L2- centric inter-cell mobility, L1 / L2 inter-cell mobility Ll / L2-Triggered Mobility, Lower-layer triggered Mobility or LTM. The basic principle is that the UE receives a lower layer signaling from the network indicating to the UE a change (or switch or activation) of its serving cell (e.g., change of PCell, from a source to a target Pcell), wherein a lower layer signaling is a message / signaling of a lower layer protocol, which may be referred as a L1 / L2 inter-cell mobility execution command or LTM cell switch command. The change of serving cell (e.g., change of Pcell) may also lead to a change in Scell(s) for the same cell group e.g., in case the command triggers the UE to change to another cell group configuration of the same type (e.g., another MCG configuration). Before the UE receives the LTM cell switch command, the UE is configured by the network with one or more LTM candidate cell configurations (e.g., reception of an RRC Reconfiguration message, with at least one LTM candidate cell configuration) A LTM candidate cell configuration may include parameters in the IE CellGroupConfig per candidate cell and / or an embedded RRC Reconfiguration per LTM candidate cell.

[0058] The term LTM cell switch procedure refers to the process of a UE switching (or changing) its cell from a source cell to a target cell (which may be called here an LTM candidate cell or a neighbour cell), using L1 / L2 -triggered mobility (LTM). In the context of L1 / L2-triggered mobility (LTM), an LTM cell switch procedure may sometimes also be known as L1 / L2 based inter-cell mobility execution, LTM execution, dynamic switch, LTM switch, LTM cell switch, LTM serving cell change or LTM cell change. In the context of the invention, switching to the LTM candidate cell configuration comprises the UE considering that an LTM candidate cell becomes its new special cell (SpCell) e.g., Pcell in case of LTM being configured for a Master Cell Group (MCG) and / or PSCell in case of LTM being configured for a Secondary Cell Group (SCG); or, changing its SpCell from the current Pcell to an LTM candidate cell.

[0059] Even if the term change of cell is used, that may comprise a change of a whole cell group configuration, which includes a change in the SpCell (e.g., change of Pcell, or change of PSCell) and a change in Scells of the cell group (e.g., addition, modification and / or release of one or more Scells).

[0060] An LTM cell switch procedure may be triggered in the UE by reception of a LTM cell switch command (e.g., LTM Cell Switch MAC CE), or alternatively, triggered by some other event, such as a condition, e.g., a triggering condition used for conditional configuration, such as conditional handover, being fulfilled, as a result of recovery from radio link failure or handover failure.

[0061] Embodiments herein may refer to a LTM candidate cell, which is a cell the UE is configured with when configured with Ll / L2-triggered mobility. That is a cell the UE can move to in a LTM cell switch procedure, upon reception of a LTM cell switch command. These cells may also be called candidate cell(s), LTM candidate cells, candidates, mobility candidates, nonserving cells, additional cells, target candidate cell, target candidate, etc. A LTM candidate cell is a cell the UE perform measurements on (e.g., CSI measurements) so that the UE reports these measurements and network may take educated decision on which beam (e.g., TCI state) and / or cell the UE is to be switched to. An LTM candidate cell may be a candidate to be a target Pcell or PSCell, or an Scell of a cell group (e.g., MCG Scell).

[0062] Embodiments herein may refer to at least one LTM candidate cell configuration and that the UE has received at least one LTM candidate cell configuration. This is also sometimes referred to as a configuration of a LTM candidate cell, which may be an RRC configuration, such as encapsulated in an RRC Reconfiguration message, that the UE receives when being configured with Ll / L2-Triggered Mobility. A LTM candidate cell configuration comprises the configuration which the UE needs to start to operate accordingly when it performs an LTM cell switch procedure to that LTM candidate cell e.g., upon reception of the LTM cell switch command indicating the UE to perform a LTM cell switch procedure to that LTM candidate cell, which becomes the target cell and the current (new) SpCell, or an SCell in a serving frequency. The LTM candidate cell configuration comprises parameters of a serving cell (ormultiple serving cells, such as a cell group), comprising one or more of the groups of parameters, such as an RRCReconfiguration message an IE CellGroupConfig or an IE SpCellConfig (or the IE SCellConfig, in the case of a Secondary Cell). A LTM candidate cell configuration may in one example comprise one or more of: i) the PCell configuration and one or more SCell configuration(s) of a Master Cell Group (MCG); i) the PSCell configuration and one or more SCell configuration(s) of a secondary Cell Group (SCG). The terms (LTM) candidate configuration, LTM configuration, (LTM) candidate target cell configuration, (LTM) target candidate (cell) configuration may be used interchangeably when referring to LTM candidate cell configuration. An LTM candidate cell configuration is associated with an identifier which is used in the signaling when referring to a certain LTM candidate cell configuration, such as when the UE receives the LTM candidate cell configuration and when the UE receives an LTM cell switch command indicating the UE to perform a LTM cell switch procedure to that LTM candidate cell. This identifier is sometimes known as the LTM candidate cell configuration identity or LTM candidate configuration index (or similar).

[0063] An actual LTM candidate cell configuration and its exact content and / or structure of this IE and / or embedded message may be called an RRC model for the candidate configuration, or simply RRC model. An LTM candidate cell configuration comprises the configuration which the UE needs to operate accordingly when it performs (executes) L1 / L2 based inter-cell mobility execution to a LTM candidate cell, upon reception of the lower layer signaling (MAC CE) indicating a L1 / L2 based inter-cell mobility to a LTM candidate cell (which becomes the target cell and the current (new) PCell, or an SCell in a serving frequency), or upon reception of the lower layer signaling (MAC CE) indicating a L1 / L2 based inter-cell mobility to a LTM candidate cell configuration indicated with a candidate configuration index (sometimes also denoted candidate configuration ID). The UE may be configured with multiple LTM candidate cell configurations, so a Candidate DU generates and sends to the CU multiple configuration(s). The actual LTM candidate cell configuration the UE receives during the LTM configuration may be a delta signaling to be applied on top of a reference configuration, so that the actual configuration the UE is to use in the candidate cell upon LTM cell switch is the combination of the LTM candidate cell configuration and the reference configuration (e.g., separately signaled by the network to the UE).

[0064] Embodiments herein refer to a report triggered by the UE upon fulfillment of a triggering condition which the UE is evaluating, the report including the measurement results that is sent by the UE to the network, called a LI report for LTM, LTM CSI measurement report, or CSI report for LI / L2 -triggered Mobility (LTM). In one option, the report includes at least one or more measurement which were used as input to the triggering conditions which havebeen fulfilled and triggered the UE to transmit report. In one option for the LTM measurement report, the UE includes a list of identifiers (e.g., resource identifiers or resource indications, or SSB identifiers) each one of them pointing to one or more SSBs and LTM candidate cells where e.g., ID1, is the first element of the list of LTM candidate cell and first element of the list of SSB. When the network receives the report, it means that the report SSB is the one identified by the first element of the list of SSB and belongs to the LTM candidate cell identified by the first element of the list of LTM candidate cells. This may also be called a resource identifier or indicator, such as an SSB resource Identifier (SSBRI), in the case of an RS being an SSB.

[0065] An LTM candidate cell may also be an LTM candidate cell in a 5G Radio access technology, such as NR, or a 6G Radio Access Technology.

[0066] Some embodiments herein refer to a RS of an LTM candidate cell, which includes an SSB and / or an RS transmitted in a beam or spatial direction, and / or a Mobility Reference Signal (MRS), a CSLRS, or a RS defined for a 6G radio interface. The term “beam” may also be used to express a spatial direction in which a Reference Signal (e.g., SSB) associated to an index (e.g., SSB index, or CSLRS index) is being transmitted, so that a beam measurement may correspond to a measurement on an RS transmitted in that beam e.g., an SSB measurement.

[0067] Some embodiments herein refer to a beam (or RS) that may be associated to a TCI e.g., by the RS (e.g., SSB) being configured as QCL source of a TCI state configuration.

[0068] Some embodiments herein refer to a trigger condition that is based on a measurement associated to an inter-frequency LTM candidate cell becoming better than absolute threshold.

[0069] According to the method, the LTM candidate cell is an inter-frequency neighbour cell, which may be called an inter-frequency LTM candidate cell, which can be defined as follows:- A cell for which Synchronization Signal Block (SSB) frequency is different than the SSB frequency of the serving cell (e.g., PCell, or PSCell) and / or the subcarrier spacing is different than the subcarrier spacing of the serving cell (e.g., PCell, or PSCell) and / or- The Synchronization Signal Block (SSB) frequency of the LTM candidate cell configured for LTM measurement is different than the SSB frequency of the serving cell (e.g., PCell, or PSCell) configured for LTM measurement; and / or- The SSB center frequency of the LTM candidate cell configured for LTM measurement is different than the SSB center frequency of the serving cell (e.g., PCell, or PSCell) configured for LTM measurement; and / or- The subcarrier spacing (SCS) of the SSB of the LTM Candidate cell (e.g., configured for LTM measurements) is different than the SCS of the serving cell (e.g., PCell, or PSCell) configured for LTM measurement; and / or- The frequency range (e.g., FRx) of the LTM candidate cell is different than the frequency range of the serving cell (e.g., FRy). The FR in this context may refer to the FR in which the SSB frequency of the LTM candidate cell and the serving cell is / are located; and / or- The frequency band of the LTM candidate cell is different than the frequency band of the serving cell; and / or- The frequency band of one RAT (e.g., NR) of the LTM candidate cell is different than the frequency band of another RAT (e.g., LTE) of the serving cell; and / orThe LTM Candidate cell is if one RAT (e.g., NR) which is different than the RAT of the serving cell (e.g., 6G RAT).

[0070] The network node configures and / or activated the triggering condition to the UE when a serving cell (for which a TCI state is activated) is overloaded e.g., has a load measurement higher than a value. The serving cell for which a TCI state is activated may corresponds to a Special Cell (SpCell), such as a Primary Cell (PCell) of the MCG or a Primary SCG Cell of a Secondary Cell Group (SCG).

[0071] The LTM candidate cell is an inter-frequency neighbour cell i.e. a cell for which Synchronization Signal Block (SSB) frequency is different than the SSB frequency of the serving cell (e.g., PCell, or PSCell) and / or the subcarrier spacing is different than the subcarrier spacing of the serving cell (e.g., PCell, or PSCell). NOTE: The condition differs from the A4 condition in TS 38.331 defined for triggering RRC Measurement Reports at least because the proposed triggering condition takes into the status of the TCI state(s) of LTM Candidate cells e.g., ‘activated’ or ‘deactivated’ TCI state(s).

[0072] According to the method, in one option, in response to the LTM lower layer report, the UE receives an LTM Cell Switch Command (e.g., LTM Cell Switch Command MAC Control Element - CE) indicating the LTM Candidate Cell (e.g., Target Configuration ID associated to an LTM candidate ID) which is an inter-frequency neighbour (e.g., in a different SSB frequency than the UE’s serving cell), and a TCI state (e.g., TCI State ID) which is to be activated in the LTM Candidate Cell which becomes the target cell. In one option, the indicated TCI state to be activate in the LTM Candidate Cell (which is an inter-frequency neighbour) in the LTM Cell Switch is associated to one of the SSBs indicated in the LTM lower layer report, whose measurement has triggered the report.- In one embodiment, the association between that reported SSB and the indicated TCI state is that the SSB is configured as Quasi-Co-Location (QCL) source of the indicated TCI State.- In one embodiment, in response to the LTM Cell Switch command, indicating an interfrequency LTM candidate cell, the UE applies an LTM candidate cell configuration associated to the LTM Candidate cell indicated in the LTM Cell Switch Command, in response to which the UE accesses the LTM Candidate cell indicated in the LTM Cell Switch command by transmitting a Scheduling Request (SR) over PUCCH in a preconfigured UL resource and / or by initiating a random access procedure (in which the UE transmits a random access preamble to the indicated LTM Candidate cell). The indicated inter-frequency LTM candidate cell is a cell which has a lower load compared to the load of the PCell the UE is coming from.In one embodiment, the UE includes in the LTM lower layer report measurement information about one or more LTM candidate cell(s) in a neighbour frequency e.g., Ll-RSRP of strongest beam (e.g., SSB, CSI-RS, MRS, RS) of the LTM Candidate cell, and in response, the UE receives an LTM Cell Switch command indicating the LTM Candidate cell which the UE has included in the LTM lower layer report and which had the beam with strongest LI -RSRP.In one embodiment, the UE includes in the LTM lower layer report measurement information about one or more LTM candidate cell(s) in a neighbour frequency e.g., Ll- RSRP of K strongest beams (e.g., SSB, CSLRS, MRS, RS) of the LTM Candidate cell, and in response, the UE receives an LTM Cell Switch command indicating the LTM Candidate cell which the UE has included in the LTM lower layer report and which had the beam with strongest LI -RSRP, and a TCI state ID for that LMT candidate cell wherein the indicated TCI State ID is associated to the beam with strongest Ll-RSRP among the reported beams in the LTM lower layer report.In one embodiment, the UE includes in the LTM lower layer report measurement information about one or more neighbour frequencies based on which the network selection which frequency is the target frequency of an LTM Candidate cell for an LTM Cell Switch. The network selects the frequency based on the load situation and the radio measurements reported by the UE e.g., frequency with lowest load measurements among the reported frequencies, and in the selected frequency, the reported cell with the strongest measurement e.g., beam with strongest Ll-RSRP.

[0073] The method also comprises that before receiving the LTM Cell Switch, in response to the LTM lower layer report the UE has transmitted, the UE receives a TCI activation command for an LTM Candidate Cell (e.g., Candidate Cell TCI States Activation / Deactivation MAC CE) indicating the LTM Candidate Cell (e.g., Target Configuration ID associated to an LTM candidate ID) which is an inter-frequency neighbour (e.g., in a different SSB frequency than the UE’s serving cell), and a TCI state (e.g., TCI State ID) which is to be pre-activated in the LTM Candidate Cell. In one option, the indicated TCI state to be activate in the LTM Candidate Cell in the LTM Cell Switch is associated to one of the SSBs indicated in the LTM lower layer report, whose first measurement has triggered the report. In one embodiment, the association between that reported SSB and the indicated TCI state is that the SSB is configured as Quasi-Co-Location (QCL) source of the indicated TCI State. In more general terms, the procedure to activate (or pre-activate) a TCI state may correspond to a Downlink (DL) synchronization procedure.

[0074] The method also comprises that before the UE receives the LTM Cell Switch, and possibly after the TCI activation command for an LTM Candidate Cell, the UE receives a command for triggering an Early Uplink sync procedure (e.g., Physical Downlink control Channel - PDCCH order), indicating an LTM Candidate Cell (which is an inter-frequency neighbour cell) and a Reference Signal (e.g., SSB identifier) based on which the UE transmits a random access preamble to the LTM Candidate Cell. In one option, the Reference Signal (e.g., SSB identifier) indicated in the command is one of the RS(s) indicated in the LTM lower layer report. In one option, the LTM candidate cell indicated in the command is one of the LTMcandidate cell(s) indicated in the LTM lower layer report including SSB(s) and / or LTM candidate cell(s) in a different frequency than the frequency of the PCell’s SSB(s).

[0075] The triggering condition (or triggering condition for transmitting an LTM lower layer report) “a measurement associated to an LTM candidate cell becomes better than absolute threshold2” may also be characterized as an event the UE is configured by network. Thus, the fulfillment of the condition may correspond to the fulfillment of the event, or the entry condition of the event.

[0076] According to the method the UE may receive, in response to transmitting the LTM lower layer report, a TCI activation command for an LTM Candidate Cell (e.g., a Candidate Cell TCI States Activation / Deactivation MAC CE), indicating an LTM Candidate Cell (which is an inter-frequency neighbour cell) and a TCI state which is to be activated in the LTM Candidate Cell. And, in response to that TCI activation command for an LTM Candidate Cell (e.g., Candidate Cell TCI States Activation / Deactivation) the UE activates the indicated TCI state of the indicated LTM Candidate cell. That may correspond to the UE performing a DL synchronization with the RS and / or beam associated to the indicated LTM candidate cell associated to the indicated TCI state.

[0077] FIG. 5 illustrates an example of a signaling flow showing the different responses the UE may receive when it triggers a lower layer LTM report (i.e. including lower layer measurements on inter-frequency LTM Candidate Cells) e.g., TCI activation command and / or command triggering early UL sync and / or an LTM Cell Switch command.

[0078] According to the method the UE may receive such TCI activation command for an LTM Candidate Cell (e.g., a Candidate Cell TCI States Activation / Deactivation MAC CE) before the UE receives an LTM Cell Switch command for an LTM Candidate Cell for triggering the LTM cell switch for inter-frequency load balancing.- In one option, the UE transmits a first instance of the LTM lower layer report, triggered by the proposed triggering condition, and in response it receives the TCI activation command for an LTM Candidate cell (e.g., LTM Candidate cell X) and an indicated TCI State (e.g., TCI state with TCI state ID=Z). Then, before the UE transmits another instance of the LTM lower layer report, the UE receives the LTM Cell Switch command indicating the same LTM Candidate cell and the same TCI state. In that case, the network only needs one instance of the LTM lower layer report to take the decision to pre-activate the TCI state of the LTM candidate cell and to indicate to the UE to perform the LTM Cell Switch to that LTM Candidate cell for inter-frequency load balancing.- In another option, the UE transmits a first instance of the LTM lower layer report, triggered by the proposed triggering condition, and in response it receives the TCI activation command for an LTM Candidate cell (e.g., LTM Candidate cell X) and an indicated TCI State (e.g., TCI state with TCI state ID=Z). Then, the UE transmits at least a second instance of the LTM lower layer report, and in response, the UE receives the LTM Cell Switch command indicating the same LTM Candidate cell and the same TCI state. In that case, the network needs multiple instances of the LTM lower layer report totake the decision to pre-activate the TCI state of the LTM candidate cell and to further indicate to the UE to perform the LTM Cell Switch to that LTM Candidate cell for interfrequency load balancing.

[0079] According to the method the UE may receive, in response to transmitting the LTM lower layer report, a command for triggering an Early Uplink sync procedure (e.g., Physical Downlink control Channel - PDCCH order), indicating an LTM Candidate Cell (which is an inter-frequency neighbour cell) and a Reference Signal (e.g., SSB identifier) based on which the UE transmits a random access preamble to the LTM Candidate Cell.- In one option the LTM candidate cell indicated in the command is one of the LTM Candidate cells indicated in the LTM lower layer report transmitted by the UE.- In one option the RS indicated in the command is one of the RSs (e.g., SSBs) indicated in the LTM lower layer report transmitted by the UE.

[0080] The command for triggering an Early UL sync procedure may further indicate to the UE one or more random access configuration indications associated to a random access configuration of the LTM Candidate Cell. In response to the command the UE transmits a random access preamble to the LTM Candidate Cell.

[0081] In another option of the method, when the command is received from the network node with in XI ms (e.g., XI is 160ms) from measurement associated with the LTM lower layer report or from the measurement LTM lower layer report, UE transmits a random-access preamble in a next random-access occasion associated to the RS indicated in the command (e.g., PDCCH order). Otherwise, the method comprises obtaining time / frequency (T / F) synchronization to the inter-frequency neighbour before transmitting the random-access preamble. The time required for obtaining T / F synchronization to the inter-frequency neighbour is Yl*SSB_Periodicity (e.g., Y1 is 3).

[0082] The method further comprising UE evaluating the event after serving cell measurement occasion and / or after each neighbour cell measurement occasion (i.e., after the LTM candidate cell configured with this event trigger).

[0083] Based on the preamble the network node associated tot eh LTM candidate cell indicated in the command, calculates a Timing Advance (TA) value, which may be included in the LTM Cell Switch command.

[0084] According to the method the UE may receive the command for triggering an Early Uplink sync procedure (e.g., Physical Downlink control Channel - PDCCH order) before the UE receives an LTM Cell Switch command for an LTM Candidate Cell.- In one option, the UE transmits a first instance of the LTM lower layer report, triggered by the proposed triggering condition, and in response it receives the command for triggering the Early UL sync procedure for an LTM Candidate cell (e.g., LTM Candidate cell X) and an indicated SSB ID. Then, after the UE transmits the preamble for the EarlyUL sync procedure, and before the UE transmits another instance of the LTM lower layer report, the UE receives the LTM Cell Switch command indicating the same LTM Candidate cell and a Timing Advance value (e.g., calculated by the network based on the preamble transmitted by the UE). In that case, the network only needs one instance of the LTM lower layer report to take the decision to triggers the Early UL sync and to indicate to the UE to perform the LTM Cell Switch to that LTM Candidate cell for interfrequency load balancing.- In another option, the UE transmits a first instance of the LTM lower layer report, triggered by the proposed triggering condition, and in response it receives the command for triggering an Early Uplink sync procedure (e.g., Physical Downlink control Channel - PDCCH order) for an LTM Candidate cell (e.g., LTM Candidate cell X) and an indicated SSB ID. Then, the UE transmits the preamble for the Early UL sync, and transmits at least a second instance of the LTM lower layer report, and in response, the UE receives the LTM Cell Switch command indicating the same LTM Candidate cell. In that case, the network needs multiple instances of the LTM lower layer report to take the decision to trigger Early UL sync and to further indicate to the UE to perform the LTM Cell Switch to that LTM Candidate cell for inter-frequency load balancing.

[0085] According to the method the UE may receive the command for triggering an Early Uplink sync procedure (e.g., Physical Downlink control Channel - PDCCH order) after the UE receives the TCI activation command for an LTM Candidate Cell (e.g., a Candidate Cell TCI States Activation / Deactivation MAC CE).- In one option, the UE transmits a first instance of the LTM lower layer report, triggered by the proposed triggering condition, and in response it receives the TCI activation command for an LTM Candidate Cell (e.g., a Candidate Cell TCI States Activation / Deactivation MAC CE), e.g., LTM Candidate cell X. In response to that the UE activates the indicates TCI state of the indicated LTM candidate cell X. Then, also in response to that first instance of the LTM lower layer report the UE also receives the command for triggering the Early UL sync procedure for the same LTM Candidate cell (e.g., LTM Candidate cell X) and an indicated SSB ID. In other words, in response to the same instance of the LTM lower layer report the UE receives the command to activate a TCI state of an LTM candidate cell and a command to trigger Early UL sync to the same LTM candidate cell (which may be an LTM candidate cell the UE has indicated in the LTM lower layer report). o In a sub-option, after the UE transmits the preamble for the Early UL sync procedure, and before the UE transmits another instance of the LTM lower layer report, the UE receives the LTM Cell Switch command indicating the same LTM Candidate cell and a Timing Advance value (e.g., calculated by the network based on the preamble transmitted by the UE). In that case, the network only needs one instance of the LTM lower layer report to take the decision to triggers TCI state activation of an LTM candidate cell, the Early UL sync, and to indicate to the UE to perform the LTM Cell Switch to that LTM Candidate cell. o In a sub-option, after the UE transmits the preamble for the Early UL sync procedure, the UE transmits at least a second instance of the LTM lower layer report and, in response to it, the UE receives the LTM Cell Switch command indicating the same LTM Candidate cell and a Timing Advance value (e.g., calculated by the network based on the preamble transmitted by the UE). In that case, the network needs a single instance of the LTM lower layer report to take the decision to triggers TCI state activation of an LTM candidate cell and theEarly UL sync, but more instances to indicate to the UE to perform the LTM Cell Switch to that LTM Candidate cell.- In one option, the UE transmits a first instance of the LTM lower layer report, triggered by the proposed triggering condition, and in response it receives the TCI activation command for an LTM Candidate Cell (e.g., a Candidate Cell TCI States Activation / Deactivation MAC CE), e.g., LTM Candidate cell X. In response to that the UE activates the indicates TCI state of the indicated LTM candidate cell X. Then, the UE transmits at least a second instance of the LTM lower layer report and, in response to, the UE receives the command for triggering the Early UL sync procedure for the same LTM Candidate cell (e.g., LTM Candidate cell X) and an indicated SSB ID. o In a sub-option, after the UE transmits the preamble for the Early UL sync procedure, and without the UE having to transmit another instance of the LTM lower layer report, the UE receives the LTM Cell Switch command indicating the same LTM Candidate cell and a Timing Advance value (e.g., calculated by the network based on the preamble transmitted by the UE). o In a sub-option, after the UE transmits the preamble for the Early UL sync procedure, the UE transmits another instance of the LTM lower layer report and, in response to it, the UE receives the LTM Cell Switch command indicating the same LTM Candidate cell and a Timing Advance value (e.g., calculated by the network based on the preamble transmitted by the UE).

[0086] According to the method, the indicated TCI state ID the UE receives in the LTM Cell Switch Command for an LTM Candidate cell or in the TCI activation command for an LTM Candidate Cell is for TCI state associated to an RS whose indication the UE has included in the LTM lower layer report. For example, the UE receives in the LTM Cell Switch a TCI ID=Z for the LTM Candidate cell X, when the UE included in the LTM lower report, an indication of the LTM Candidate cell X and an SSB whose SSB ID=Y, wherein the SSB ID=Y is configured as QCL source of the TCI ID=Z of the LTM Candidate cell X.

[0087] And, the indicated RS ID the UE receives in the command for triggering an Early Uplink sync procedure (e.g., PDCCH order) for an LTM Candidate cell is an RS ID whose indication the UE has included in the LTM lower layer report. For example, the UE receives in the PDCCH order an SSB ID=Y for the LTM Candidate cell X, when the UE included in the LTM lower report, an indication of the LTM Candidate cell X and an indication of SSB ID=Y.

[0088] According to the method, the UE perform measurements and / or evaluates the triggering condition on the LTM candidate cell, for transmitting LTM lower layer reports, depending on the status of a TCI state of the LTM candidate cell, wherein the status may be ‘activated’ or ‘deactivated’.

[0089] In one set of option, according to the method, the UE perform measurements and / or evaluates the fulfillment of the triggering condition on LTM candidate cell(s) (which is / are interfrequency LTM candidate cell(s) when that LTM candidate cell has at least one TCI state activated. Or, the UE perform measurements and / or evaluates the fulfillment of the triggeringcondition on LTM candidate cell(s) (which is / are inter-frequency LTM candidate cell(s) when that LTM candidate cell has all its TCI states deactivated.- In one option, the UE is configured with two instances of the triggering condition, e.g., with different value(s) for the threshold to be compared with the measurement of the inter-frequency LTM candidate cell. A first instance of the LTM lower layer report (triggered based on the proposed condition) is to be triggered earlier than the other (e.g., threshold value for comparing with the LTM Candidate cell is lower), to assist the network to first activate TCI state of an LTM candidate cell and, only later, to trigger an LTM Cell Switch. In that sense, the first instance is monitored by the UE for a deactivate inter-frequency LTM Candidate cell and, when that inter-frequency LTM candidate cell gets activated, the UE stops evaluating the first instance (e.g., with first absolute threshold value) and starts evaluating the second instance (with the second absolute threshold value), since that is an inter-frequency LTM Candidate Cell which is sort of ‘ready’ for a fast inter-frequency LTM Cell switch. o In one sub-option, the two instances may be configured in two different reporting configuration instances e.g., two different instances of LTM-CSI-ReportConfig IE(s), each with its own reporting configuration identifier.■ In one option, the UE switches (e.g., autonomously) between these two depending whether the inter-frequency LTM candidate cell has at least one TCI state or not. Switching in this context means evaluating or not the trigger condition, and / or performing the associated measurement(s).■ In another option, the UE switches between these two based on a signaling from the network indicating which reporting configuration to evaluate and to not evaluate e.g., MAC CE indicating a reporting configuration Id.■ In another option, the UE switches between these two based on a MAC CE the UE receives to activate or deactivate a TCI state of an LTM Candidate Cell. When an LTM Candidate cell has all its TCIs states deactivated, the UE is evaluating the first instance of the reporting configuration (first absolute thresholds value for early trigger of presync); the UE may transmits the LTM lower layer report and in response receive a MAC CE indicating the activation of a TCI state of that LTM candidate cell; then, in response to that MAC CE, the UE stops evaluating the first instance, and starts evaluating the second instance.■ In another option, the UE switches between these two based on a new MAC CE the UE receives to toggle between reporting configurations to be evaluated. o In one sub-option, this is a single reporting configuration instance, which may take the two (or more) values of absolute thresholds.■ In one option, the UE switches (e.g., autonomously) between these two threshold values depending whether the inter-frequency LTM candidate cell has at least one TCI state or not. Switching in this context means evaluating or not the trigger condition, and / or performing the associated measurement s).■ In another option, the UE switches between these two threshold values based on a signaling from the network indicating for a given reporting configuration to evaluate (e.g., MAC CE indicating a reporting configuration Id), which value of threshold to consider.■ In another option, the UE switches between these two threshold values to evaluate based on a MAC CE the UE receives to activate or deactivate a TCI state of an LTM Candidate Cell. When an LTM Candidate cell hasall its TCI states deactivated, the UE is evaluating the first instance of the reporting configuration (first threshold value for early trigger of presync); the UE may transmits the LTM lower layer report and in response receive a MAC CE indicating the activation of a TCI state of that LTM candidate cell; then, in response to that MAC CE, the UE stops evaluating the first instance, and starts evaluating the second instance.■ In another option, the UE switches between these two threshold values based on a new MAC CE the UE receives to toggle between these pairs, for a given reporting configuration. o In one sub-option, instead of two values of thresholds, to be evaluated depending on whether the LTM candidate cell has activated TCI states or not, the UE is configured with an absolute threshold value and one or more offset(s), wherein the offset(s) are applied depending on whether the LTM candidate cell has activated TCI states or not.

[0090] When the UE performs measurement s) on an LTM candidate cell which has a TCI activated, the UE perform the measurements on a beam of the LTM Candidate cell associated to the activate TCI state of the LTM candidate cell e.g., on an RS and / or SSB and / or CSLRS of the LTM Candidate cell configured as QCL source of the activated TCI state of the LTM candidate cell.

[0091] When the UE performs measurement s) on an LTM candidate cell which has a TCI state deactivated, the UE performs the measurements on a beam of the LTM Candidate cell configured as QCL source of the deactivate TCI state of the LTM candidate cell e.g., on an RS and / or SSB and / or CSLRS of the LTM Candidate cell configured as QCL source of the deactivated TCI state of the LTM candidate cell.

[0092] According to the method the UE may receive a message (e.g., an RRC Reconfiguration message) including one or more parameters (e.g., fields and / or Information Element(s) and / or instances of IE(s)) for configuring the triggering condition, and, upon receiving the one or more parameters the UE evaluates the fulfillment of the triggering condition and / or perform one or more measurements on one or more LTM candidate cell(s) and / or RS(s), SSB(s), CSLRS, Mobility Reference Signal(s) (MRSs) of one or more LTM candidate cell(s). The one or more parameters for configuring the triggering condition comprises one or more of a time to trigger value (e.g., in time units), a trigger quantity (e.g., LI RSRP, LI SINR, LI RSRQ, etc.), one or more reporting quantities (e.g., LI RSRP, LI SINR, LI RSRQ, etc.) indicating to the UE what to include the LTM lower layer report e.g., in addition to the trigger quantities, a reference signal type (e.g., SSB or CSLRS), an indication of an associated resource configuration (e.g., resource configuration identifier), a value for threshold used to compare the associated measurements on the inter-frequency LTM Candidate, an event identifier (for identifying the trigger condition defined “measurement on inter-frequency LTM candidate cell better than absolute threshold”). Since these trigger conditions are to assist inter-frequency loadbalancing LTM Cell Switches, they might not be configured to the UE at the same message in which the UE is configured with LTM Candidate cells, but in a subsequent message e.g., another RRC Reconfiguration message, received by the UE when the UE is already configured with LTM candidate cell(s).

[0093] In one option of the method, the UE receives the configuration of the one or more parameters but does not start to evaluate the conditions. The UE only evaluates the conditions after further receiving another command (associated to the previously received configuration). For example, the configuration with one or more parameters may be associated to a reporting configuration which has a reporting configuration identifier (e.g., LTM-CSI-ReportConfigld). Then, the receives a command associated to a first reporting configuration (e.g., a MAC CE, a PDCCH order and / or a Downlink Control Indication - DCI), by including an indication of a configured reporting configuration, e.g., a reporting configuration identifier set to X. When the reporting configuration identifier received in the command matches the reporting configuration identifier of the first reporting (e.g., reporting configuration identifier in the command = X) the UE evaluates the fulfillment of the trigger condition and / or perform the one or more measurements associated to the resource configuration associated to the reporting configuration.

[0094] In one option, the UE receives a command associated to the reporting configuration includes an indication of one or more frequencies (e.g., one or more measurement object identifiers), indicating to the UE to monitor the trigger condition of the reporting configuration only for the LTM candidate cells in the indicated one or more frequencies. The actual frequencies may be determined by the network e.g., in response to a load balancing function, so that the network indicate frequencies which are good candidates from a load balancing perspective. When the UE receives the command, the UE considers the LTM Candidate cell sin the indicated frequencies as the applicable cells for the trigger condition (LTM candidate cell better than absolute thrhesold). The benefit is that the UE would not need to measure LMT candidate cells in neighbour frequencies unnecessarily, since some of these frequencies may also be overloaded, as the PCell frequency. The scheme may be beneficial compared to a reconfiguration (in which the resource configuration could be modified to include / exclude LTM candidates cells in neighbour frequnecies depending on their load situation), if the command is a lower layer signaling (like a MAC CE, DCI, PDCCH order) to also adapt to the fast load variations in different carriers. Alternatively, the UE may receive int eh command one or more indications of frequecnies to NOT consider as applicable for evaluation of the trigger condition.

[0095] In one option of the method, the UE receives the configuration of the one or more parameters but does not start to evaluate the conditions. The UE only evaluates the conditions after further receiving another command (associated to the previously received configuration)for activating the reporting configuration of the trigger condition e.g., when the PCell load gets topo high. Then, the UE further receives a command to deactivate the reporting configuration for the trigger condition when e.g., the network determines that the load of the PCell is not high any longer. For example, the configuration with one or more parameters may be associated to a reporting configuration which has a reporting configuration identifier (e.g., LTM-CSI- ReportConfigld) and the UE is evaluating that trigger condition. Then, the UE receives a command associated to a first reporting configuration (e.g., a MAC CE, a PDCCH order and / or a Downlink Control Indication - DCI), by including an indication of a configured reporting configuration, e.g., a reporting configuration identifier set to X. When the reporting configuration identifier received in the command matches the reporting configuration identifier of the first reporting (e.g., reporting configuration identifier in the command = X) the UE stops evaluating the fulfillment of the trigger condition and / or stops performing the one or more measurements associated to the resource configuration associated to the reporting configuration.

[0096] In one option, the configuration of the trigger condition and / or the command to activate the reporting configuration is transmitted by the network in response to a load balancing function which identifies that the PCell of the UE is overloaded e.g., has too many connected UE(s), or a number of UE(s) with significant traffic demands, and / or simply has traffic demands higher than what the PCell bandwidth is able to support to guarantee a reasonable quality of experience to the UE(s).

[0097] In one option, the load measurement function acts on a network node which is a Centralized Unit (CU) e.g., responsible for traffic control, such as CU-User Plane (UP) function. That function in the CU-UP may indicate the load situation to the CU-CP, which determines to trigger actions related to load balancing, such as:- i) the configuration of the reporting configuration associated to the trigger condition, for the UE to transmit an LTM lower layer report when an inter-frequency LTM candidate cell is better than a threshold; in option, when that is determined, the CU-CP may transmit a request to the Serving / Source Distributed Unit (S-DU), in case it is the S-DU which needs to configure reporting configuration(s) e.g., as part of the UE’s lower layer current configuration which is to be updated. The request may include the necessary information for the S-DU to configure the triggering condition, such as information on one or more neighbour frequencies (e.g., SSB frequency different than the PCell, possibly in a different frequency band) which are considered as candidates for a load balancing LTM Cell Switch e.g., in the form of a list of absolute frequency values (e.g., ARFCN) and / or frequency band indications and / or SSB frequency value(s), etc. The frequency information may be used by the S-DU for configuring the resource configuration e.g., by including only resources (SSBs and / or indications of LTM candidate cells) on the candidate frequencies, as indicated by the CU.- i) the 'activation’ of a configured reporting configuration (e.g., by including a reporting configuration identifier) associated to the trigger condition, for the UE to transmit an LTM lower layer report when an inter-frequency LTM candidate cell is better than a threshold; in option, when that is determined, the CU-CP may transmit a command (or asecond request) to the Serving / Source Distributed Unit (S-DU), in case the S-DU needs to 'activate’ the reporting configuration(s) e.g., by transmitting a lower layer signaling like a MAC CE, PDCCH order or DCI, indicating a reporting condition identifier. The command from the CU to the S-DU may include the necessary information for the S-DU to activate the triggering condition, such as information on one or more neighbour frequencies (e.g., SSB frequency different than the PCell, possibly in a different frequency band) which are considered as candidates for a load balancing LTM Cell Switch e.g., in the form of a list of absolute frequency values (e.g., ARFCN) and / or frequency band indications and / or SSB frequency value(s), etc. The frequency information may be used by the S-DU for configuring the resource configuration e.g., by including only resources (SSBs and / or indications of LTM candidate cells) on the candidate frequencies, as indicated by the CU. The indicated information about neighbour frequencies, considered as candidates, may be a subset of neighbour frequencies the UE is configured with in a resource configuration associated to the reporting configuration in which the trigger condition is configured (e.g., the CU may determine the subset based on the output of a load balance function, by determining the neighbour frequencies with lower load, so the load may be balanced across carriers).

[0098] In one option, the S-DU receives the LTM lower layer report, indicates to the CU, and receives an indication of which neighbour frequency is to be the target frequency, wherein the CU determines that e.g., based on the load of the target frequency and possibly the load of other neighbour frequencies. For example, when the LTM lower layer report is received at the S- DU (based on the trigger condition at the UE is fulfilled, i.e. measurement of at least one interfrequency LTM candidate cell is better than absolute threshold), the S-DU forwards the LTM lower layer report to the CU (or information from the report); the LTM lower layer report may include information on one or more LTM candidate cells from one or more neighbour frequencies and / or frequency bands, as measured by the UE. Then, the CU, based on one or more load measurements available (e.g., possibly obtained from the CU-UP), and the information from the LTM lower layer report forwarded from the S-DU, the CU determines which neighbour frequency is to be the target frequency for the LTM Cell Switch and indicates a target frequency information to the S-DU, so that the S-DU determines an LTM candidate cell in that target frequency and includes in the LTM Cell Switch command to the UE an indication of the LTM Candidate cell in that target frequency. In other words, the CU determines the target frequency based on the load, but it is the S-DU which determines the LTM candidate cell in that target frequency, to be indicated in the LTM Cell Switch command. It is also the S-DU which determines the other parameters / fields in the MAC CE, such as Time Alignment value, random access related parameters, TCI state related information, etc.

[0099] In one option, the S-DU receives the LTM lower layer report, indicates to the CU, and receives an indication of which neighbour frequency and LTM candidate cell is to be the target frequency and cell, wherein the CU determines that e.g., based on the load of the target frequency and possibly the load of other neighbour frequencies. For example, when the LTMlower layer report is received at the S-DU (based on the trigger condition at the UE is fulfilled, i.e. measurement of at least one inter-frequency LTM candidate cell is better than absolute threshold), the S-DU forwards the LTM lower layer report to the CU (or information from the report); the LTM lower layer report may include information on one or more LTM candidate cells from one or more neighbour frequencies and / or frequency bands, as measured by the UE. Then, the CU, based on one or more load measurements available (e.g., possibly obtained from the CU-UP), and the information from the LTM lower layer report forwarded from the S-DU, the CU determines which neighbour frequency and LTM candidate cell in that frequency is to be the target frequency and cell for the LTM Cell Switch and indicates a target cell (and possibly frequency) information to the S-DU, so that the S-DU includes in the LTM Cell Switch command to the UE an indication of the LTM Candidate cell. In other words, the CU determines the target frequency based on the load, and the LTM Candidate cell to be the target cell and simply indicates to the S-DU, to be indicated in the LTM Cell Switch command to the UE. It is the S-DU which determines the other parameters / fields in the MAC CE, such as Time Alignment value, random access related parameters, TCI state related information, etc.

[0100] FIG. 10 illustrates an example of a communications network architecture with a CU / DU split.

[0101] When the S-DU receives the indication from the CU on a target frequency (e.g., out of neighbour frequencies reported by the UE in the LTM lower layer report) the S-DU is not limited to trigger the LTM Cell Switch command to an LTM Candidate cell in that frequency, but it may trigger (e.g., before the LTM Cell Switch command) an Early Uplink sync and / or a pre-activation of a candidate TCI state, for the LTM candidate cell in the target frequency.

[0102] FIG. 11 illustrates an example of interactions between a UE, S-DU, CU, and a C-DU for a load balancing triggered inter-frequency LTM cell switch.

[0103] The method further comprising for the network node which receives the LTM lower layer report, e.g., the serving DU, to contact another network node to either request which LTM candidate cell to consider for triggering either and LTM cell switch, a TCI state activation, or early UL synchronization procedure. This “another network node” can be the CU, which is the node which understand what is the current load balancing on several cells and thus can take the right decision on which LTM candidate cell to select. In another option on this method, the decision on which LTM candidate cell to select is still part of the network node which receives the LTM lower layer report, but in such a case the “another network node”, e.g., the CU, would need to share load balance statistics which the network node which receives the LTM lower layer report. In this case, the sharing of the load balancing statistic can be periodical (regardless on the reception of the LTM lower layer report or request from the network node which receivesthe LTM lower layer report) or can be upon a request from the network node which receives theLTM lower layer report.

[0104] First variant: comparison of beam measurements

[0105] In a set of embodiments, the UE triggers an LTM lower layer report when the “best” beam (or RS) of the LTM candidate cell (e.g., highest LI RSRP), in a different frequency as the serving cell, becomes better than an absolute threshold.

[0106] There are different options for defining a “best” beam, which would make the UE to determine the input to the triggering condition, such as:- The “best” beam of the LTM candidate cell may corresponds to the beam (or RS e.g., SSB, CSLRS, MRS, etc.) with the highest measurement quantity among other beams (or RSs) of the LTM candidate cell (e.g., highest LI RSRP).- The “best” beam (or RS) of the LTM candidate cell may correspond to the beam (or RS) associated with an activated candidate TCI state of the LTM Candidate cell. In this case the beam may be represented by an RS, such as an SSB and, the best beam corresponds to the SSB configured as QCL source of the activated TCI state in the LTM Candidate Cell. A candidate TCI state of an LTM Candidate Cell may be activated before an LTM Cell Switch command is received. The activation occurs in response to the reception by the UE of a MAC CE (e.g., Candidate Cell TCI States Activation / Deactivation MAC CE). o When the LTM Candidate Cell has a single TCI state activated, the UE considers the best beam as the beam associated to that activated TCI State. For example, let us assume that an LTM Candidate Cell has candidate TCI state activated with configured QCL source [SSB2], Then, the UE considers SSB2 as the best beam of that LTM Candidate Cell. o When the LTM Candidate Cell has multiple TCI states activated, one option is to consider the best beam as the one associated to the highest measurement quantity among the beams associated to activated TCI States of the LTM Candidate Cell. For example, let us assume that the LTM Candidate Cell has 3 TCI states activated, with configured QCL sources [SSB2], [SSB5], [SSB7] wherein the SSB with the highest LI -RSRP is of SSB5. Then, the UE considers SSB5 as the best beam of that LTM Candidate Cell.- The “best” beam (or RS) of the LTM candidate cell may corresponds to the beam (or RS e.g., SSB, CSLRS, MRS, etc.) which average measurement quantity (over a time window) is with the highest measurement quantity among other beams (or RSs) of the LTM candidate cell (e.g., highest LI RSRP).- The “best” beam (or RS) of the LTM candidate cell may correspond to any of what is described above, but considering beams which belong to a PCell, PSCell, or SCell(s) (or any permutation of these).

[0107] In one option, the UE triggers an LTM lower layer report when the LI RSRP of anSSB of the LTM candidate cell is better than threshold.

[0108] According to the method, the “best” beam of the LTM Candidate cell may change over time for example, in a measurement period tO the best beam may be bl, in measurement period tl the best beam may be b5, and in measurement period the best beam may be b7. In thatcase, the UE may have a best beam measurement per period and perform an average to define a best beam quality, even if the best beam differs for the different measurement periods.

[0109] According to the method the UE may receive an RRC message for configuring one or more parameters associated to the triggering conditions (which may also be called an event or entering condition associated to the event). The RRC message (e.g., RRC Reconfiguration) may include a reporting configuration (e.g., LTM-CSI-ReportConfig) and an association resource configuration (e.g., LTM-CSI-ResourceConfig). Upon receiving the one or more parameters the UE evaluates the fulfillment of the triggering condition.

[0110] The reporting configuration may indicate an identifier (e.g., event ID) so that when the UE receives the configuration the UE determines that the configuration is for the event whose condition is defined as follows: the “best” beam (or RS) of the LTM candidate cell (e.g., highest LI RSRP), in a different frequency as the serving cell, becomes better than threshold.

[0111] The reporting configuration may indicate one or more parameters associated to the event such as:- a trigger quantity, indicating what is the quantity to be measured and used as input to the triggering condition e.g., RSRP, RSRQ, SINR, LI RSRP, etc.- a threshold value, associated to the event definition e.g., in terms of dBs or dBm;- one or more reporting quantities, indicating what additional quantities the UE is meant to measure and / or report, in addition to the trigger quantity.- a time to trigger value, which indicates how long since the condition has been fulfilled the UE needs to way before sending the measurement report.- an LTM candidate cell ID, which indicate to which LTM candidate configuration the event applies- a reference signal type (e.g., SSB or CSLRS)- an indication of an associated resource configuration (e.g., resource configuration identifier)- a reporting configuration identifier- one or more indications of a neighbour frequency (e.g., measurement object identifier), to indicate to the frequencies of the LTM candidate cells in the associated resource configuration to be considered as applicable.

[0112] The reporting configuration may indicate an identifier of a resource configuration (e.g., LTM-CSI-ReportConfigld, included in the reporting configuration), which indicates one or more LTM Candidate Cells to be possibly considered as input for the condition associated to the event. Thus, the UE determines the LTM Candidate Cells for which beams / SSB(s) within the resource configuration are to be considered as input to the event(s) e.g., the SSBs of the LTM Candidate Cell(s) and / or the SSBs of the Serving cell (e.g., the SpCell or PCell). In other words, even when the UE is configured with more LTM Candidate Cells which may be detected by the UE, these are not considered as applicable cells to be used as input to the events unless they are included in the resource configuration.

[0113] For example, for some of the embodiments disclosed in the method, the UE evaluates the fulfillment of the triggering conditions for an LTM candidate cell when that has at least one activated TCI state. Applying this concept, the UE only considers the resources in the resource configuration associated to the reporting configuration for the proposed event, when that is of an LTM Candidate Cell which has at least one activated TCI state.

[0114] Or, as in some of the embodiments disclosed in the method, the UE evaluates the fulfillment of the triggering conditions for RSs of an LTM candidate cell which are associated to Activated TCI states. Thus, the UE only considers the resources in the resource configuration (e.g., RS ID(s), SSB ID(s)) associated to the reporting configuration for the proposed event, when these SSB ID(s) or RS ID(s) are configured as QCL source of activated TCI states of LTM Candidate cells.

[0115] In one option, the RS (e.g., SSB or CSLRS) to be considered may be explicitly indicated by the NW in the report configuration. One example this may be a simple indication like consider all RS configured or only the beams / RS associated with TCI states activated or the RS / beams not associated with TCI states activated. This can be indicated to UE in the report configuration as following.ItmRSForEventEvaluation ENUMERATED {All LTM candidate RS, LTM candidate RS associated with TCI states activated, LTM candidate RS not associated with activated TCI states, Spare}

[0116] For example, based on intended usage of the event by the NW, ItmRSForEventEvaluation can be configured appropriately by NW. If the NW intend to use the event for selecting the cells / RS for DL and UL pre-synchronization, NW may indicate above field as LTM candidate RS not associated with activated TCI states. If the NW intend to use the event for cell switch for load balancing, NW can indicate LTM candidate RS associated with TCI states activated and so on.

[0117] In one option, a resource configuration may include resources of LTM Candidate cells which are inter-frequency candidate cell(s) (e.g., SSB ID(s) associated to an LTM candidate ID) and resources of LTM Candidate cells which are NOT inter-frequency candidate cell(s) (e.g., SSB ID(s) associated to an LTM candidate ID). Thus, as the event defined as follow “the “best” beam (or RS) of the LTM candidate cell (e.g., highest LI RSRP), in a different frequency as the serving cell, becomes better than threshold” is applicable for inter-frequency LTM candidate cell(s), the UE only considers for comparing the measurement of the LTM candidate cell with threshold, the resources associated to inter-frequency LTM Candidate cell(s).- In other words, the applicable cells are the inter-frequency LTM candidate cells among the LTM candidate cells in the resource configuration associated to the reporting configuration in which the event is configured.- In other words, the applicable beams, SSBs and / or RS ID(s) are the ones of interfrequency LTM candidate cells among the LTM candidate cells in the resource configuration associated to the reporting configuration in which the event is configured.

[0118] One alternative which might not require such a rule, could be if the UE would be configured with a resource configuration only with inter-frequency LTM candidate cell(s) with lower load than the carrier frequency of the PCell (known to the network). However, that would require different sets of resource configuration(s). Thus, it may be beneficial to define resource configuration(s) including both intra-frequency LTM Candidate cells and inter-frequency LTM candidate cell(s). And, to properly operate with the different events, the UE would need to consider only inter-frequency LTM candidate cells for the event defined as “the “best” beam (or RS) of the LTM candidate cell (e.g., highest LI RSRP) becoming better than threshold.

[0119] For example, let us assume an instance of the IE LTM-CSI-ResourceConfig-rl8 (having an associated identifier e.g., ltm-CSI-ResourceConfigId-rl8) and being grouped in as a resource set (e.g., in the IE LTM-CSI-SSB-ResourceSet-rl8), wherein the resource set may be structure as a first and a second list, wherein the first list comprises one or more SSB indexes and the second list comprises one or more LTM candidate cell identifiers (IDs), wherein the position in the list is associated to an LTM CSI resource in that LTM CSI resource configuration e.g., the instance of the IE LTM-CSI-ResourceConfig includes the following lists Itm-CSLSSB- ResourceList-rl8 and ltm-CandidateIdList-r!8: ltm-CSI-SSB-ResourceList-rl8 Itm-CandidateldList-r 18• [SSB1] [LTM Candidate cell ID 1]• [SSB2] [LTM Candidate cell ID 1]• [SSB3] [LTM Candidate cell ID 1]• [SSB4] [LTM Candidate cell ID 1]• [SSB5] [LTM Candidate cell ID 1]• [SSB1] [LTM Candidate cell ID 2]• [SSB2] [LTM Candidate cell ID 2]• [SSB3] [LTM Candidate cell ID 2]• [SSB4] [LTM Candidate cell ID 2]• [SSB5] [LTM Candidate cell ID 2]• [SSB1] [LTM Candidate cell ID 3]• [SSB2] [LTM Candidate cell ID 3]• [SSB3] [LTM Candidate cell ID 3]• [SSB4] [LTM Candidate cell ID 3]• [SSB5] [LTM Candidate cell ID 3]• [SSB1] [LTM Candidate cell ID 4]• [SSB2] [LTM Candidate cell ID 4]• [SSB3] [LTM Candidate cell ID 4]• [SSB4] [LTM Candidate cell ID 4]• [SSB5] [LTM Candidate cell ID 4]• [SSB1] [LTM Candidate cell ID 5]• [SSB2] [LTM Candidate cell ID 5]• [SSB3] [LTM Candidate cell ID 5]• [SSB4] [LTM Candidate cell ID 5]• [SSB5] [LTM Candidate cell ID 5]

[0120] In this example, LTM Candidate cells with ID 2 and ID 4 are the inter-frequency LTM Candidate Cell(s). Then, only LTM Candidate cells with ID 2 and ID 4 are applicable when that resource configuration is indicated in a reporting configuration configuring the event “the “best” beam (or RS) of the LTM candidate cell (e.g., highest LI RSRP) becomes better than threshold.”

[0121] And, even when the UE has other SSBs per LTM Candidate cells which may be detected, the UE monitors the triggering condition associated to that resource configuration the [SSB1], [SSB2], [SSB3], [SSB4], [SSB5] of the LTM candidate cell ID 2 and the [SSB1], [SSB2], [SSB3], [SSB4], [SSB5] of the LTM candidate cell ID 4.

[0122] In one option, not all SSBs of an inter-frequency LTM Candidate Cell which are included in the resource configuration are applicable to be considered as input to the triggering condition, but the SSBs in the resource configuration which are associated to the activated LTM candidate cell which is also in the resource configuration. Assuming the example above, in which [LTM Candidate cell ID 2] is activated, but [LTM Candidate cell ID 4] is deactivated, only [LTM Candidate cell ID 2] is to be evaluated in comparison with the serving cell.

[0123] In another option, not all SSBs of an inter-frequency LTM Candidate Cell which are included in the resource configuration are applicable to be considered as input to the triggering condition, but the SSBs in the resource configuration which are associated to the activated TCI state(s) of the LTM candidate cell e.g., SSBs configured as QCL source of a candidate TCI state which is activated. Assuming the example above, in which [LTM Candidate cell ID 2] is activated (SSB5), [SSB5] of [LTM Candidate cell ID 2] is to be evaluated in comparison with the best beam of the serving cell (e.g., of the PCell).

[0124] In another option, not all SSBs of a serving cell (e.g., SpCell, PCell) which are included in the resource configuration are applicable to be considered as input to the triggering condition, but the SSBs in the resource configuration which are associated to the activated TCI state(s) of the serving cell e.g., SSBs configured as QCL source of a TCI state which is activated.

[0125] In one option, the reporting configuration is associated to an LTM candidate ID, and no explicitly SSB list is provided in a resource configuration. The UE determines the SSBs associated to the LTM Candidate ID which may be considered as input to the event / triggering condition by obtaining the TCI state configuration. The SSBs considered as possible input arethe SSBs configured as QCL source(s) in the Candidate TCI state configuration associated to the LTM candidate cell.

[0126] In a set of embodiments, multiple inter-frequency LTM Candidate cell(s) fulfill the triggering condition: the “best” beam (or RS) of the LTM candidate cell (e.g., highest LI RSRP), in a different frequency as the serving cell, becomes better than threshold. In other words, the best beam of multiple inter-frequency LTM Candidate cell(s) may, at a certain point in time, be better than threshold.

[0127] In one example, when multiple beams trigger the report, the report include single beam’s report whose LI -RSRP is highest among the beams which triggered the event. In other example, report include all the beams and their cell IDs which triggers the event.

[0128] In one example the report includes top N beam’s Ll-RSRP corresponding to single LTM candidate cell. In other example, LTM lower layer report includes top N beams corresponding to different LTM candidate cells which trigger the event.

[0129] LTM lower layer reporting

[0130] According to the method, the UE transmits an LTM lower layer report when the triggering condition is fulfilled i.e., the “best” beam (or RS) of the LTM candidate cell (e.g., highest LI RSRP), in a different frequency as the serving cell, becomes better than threshold, wherein the UE includes one or more of the following in the LTM lower layer report.- Information about the best “beam” (or RS) of the inter-frequency LTM Candidate Cell which has triggered the event (e.g., so-called triggered SSB) such as: o An indication of a value of the measurement quantity which has triggered the report e.g., Ll-RSRP associated to that beam or RS; o An indication of a value of a measurement quantity configured at the UE (e.g., reporting quantity(ies) configured in the LTM reporting configuration) e.g., Ll- RSRQ associated to that beam or RS; o A differential measurement quantity (e.g., differential LI RSRP) associated to that best beam (e.g., relative to a reference value); o An indication of the best beam or RS such as, a beam identifier of the best beam, an RS index (e.g., SSB index) or a resource indication, indicating the position of that best beam in the associated resource configuration, such as an SSB Resource Indicator (SSBRI), in the case of an SSB being configured as a resource;- Information about the best “beam” (or RS) and the top N beams of the LTM Candidate Cell which has triggered the event (e.g., so-called triggered SSB) such as: o An indication of a value of the measurement quantity which has triggered the report e.g., Ll-RSRP associated to that beam or RS; o An indication of a value of a measurement quantity configured at the UE (e.g., reporting quantity(ies) configured in the LTM reporting configuration) e.g., Ll- RSRQ associated to that beam or RS; o A differential measurement quantity (e.g., differential LI RSRP) associated to that best beam (e.g., relative to a reference value); o An indication of the best beam or RS such as, a beam identifier of the best beam, an RS index (e.g., SSB index) or a resource indication, indicating the position ofthat best beam in the associated resource configuration, such as an SSB Resource Indicator (SSBRI), in the case of an SSB being configured as a resource; o N may be configurable or fixed quantity- Information about the best “beam” (or RS) of the Serving Cell such as: o An indication of a value of the measurement quantity which has triggered the report e.g., Ll-RSRP associated to that beam or RS; o An indication of a value of a measurement quantity configured at the UE (e.g., reporting quantity(ies) configured in the LTM reporting configuration) e.g., Ll- RSRQ associated to that beam or RS; o A differential measurement quantity (e.g., differential LI RSRP) associated to that best beam (e.g., relative to a reference value); o An indication of the best beam or RS such as, a beam identifier of the best beam, an RS index (e.g., SSB index) or a resource indication, indicating the position of that best beam in the associated resource configuration, such as an SSB Resource Indicator (SSBRI), in the case of an SSB being configured as a resource; o Note: this may be included in case the associated reporting configuration includes an indication requesting the UE to include information about one or more serving cell(s).- Information about the LTM candidate cell associated to the “best” beam and / or best SSB and / or triggered SSB o LTM Candidate ID e.g., encoded in fewer bits than the cell identity and associated to an LTM Candidate cell configuration, configured when LTM is configured; o Cell identifier (Cell ID) of the LTM Candidate cell associated to the beam or RS which has triggered the LTM lower layer report;■ This may be a Serving cell index or SCell index depending on whether the LTM candidate cell has been configured as a PCell, PSCell, or SCell. o Physical Cell Identity (PCI) of the LTM candidate cell associated to the beam or RS which has triggered the LTM lower layer report;SSB Frequency (e.g., absolute frequency information, like an ARFCN of the SSB) of the LTM candidate cell associated to the beam or RS which has triggered the LTM lower layer report;- Information about the Serving cell e.g., Pcell associated to the “best” beam and / or best SSB of the Serving cell o LTM Candidate ID e.g., encoded in fewer bits than the cell identity and associated to the current serving cell, also configured as an LTM Candidate cell configuration, configured when LTM is configured; o Cell identifier (Cell ID) of the Serving Cell associated to the beam or RS which has triggered the LTM lower layer report;■ This may be a Serving cell index or SCell index depending on whether the LTM candidate cell has been configured as a PCell, PSCell, or SCell. o Physical Cell Identity (PCI) of the Serving Cell associated to the beam or RS which has triggered the LTM lower layer report; o SSB Frequency (e.g., ARFCN of the SSB) of the Serving Cell associated to the beam or RS which has triggered the LTM lower layer report; o Note: this may be included in case the associated reporting configuration includes an indication requesting the UE to include information about one or more serving cell(s).- An identifier associated to the measurement which is being triggered e.g., a reporting configuration identifier, and / or a resource configuration identifier, or another identifier associated to the reporting configuration identifier o An Event ID, if there are multiple events configured for one or more LTM candidate cells, but e.g., with different conditions or parameters. o Configuration ID, if one event ID is configured with multiple configuration ID. E.g., one config ID can be configured with one set of thresholds for selecting cells with TCI state activation. Other set of configurations with other set of thresholds for cell switch for load balancing.- Time stamp information about the last measurement occasion for the inter-frequency neighbour cell that triggered the event. o In one example the reporting granularity of the time stamp can be in the order of number SSB periods. This can be reported in terms of number of SSB periods of the inter-frequency neighbors. For example, if the event is evaluated after the serving cell measurement (serving cell became lower than threshold after latest measurement while the neighbour cell was higher than threshold before this measurement), if the inter-frequency cell measurement was made 2 SSB period earlier than the serving cell measurement, UE reports this field as 2. o This is particularly useful for the NW to understand the T / F validity of the LTM inter-frequency candidate cell so that NW can schedule the PRACH preamble occasion as per this report. o In one example, if the inter-frequency neighbour was measured more than 160ms before the serving cell measurement that triggered the report, NW can schedule the PRACH transmission after 60ms (e.g., Yl*SSB_period, Y1 is 3 and SSB _period is 20ms). This helps NW utilize the PRACH preamble occasions effectively. o In another example, NW can configure a time threshold for the last measured occasion such as Y1 ms. In this example, UE reports 1 if UE has measured the SSB within last Y1 ms. Else UE reports 0. In one example NW may configure Y1 as 80ms. In another example NW may configure 160ms. In some other examples, Y 1 value may be a fixed value in the spec than the configurable value.

[0131] For that set of embodiments, the UE transmits the LTM lower layer report e.g., by transmitting a MAC Control Element, and / or a report over PUSCH and / or PUCCH. In the case of an LTM lower layer report on a MAC CE, the UE transmits a scheduling request before it receives an UL grant for transmitting the LTM lower layer report.

[0132] The fulfillment of the triggering condition may be expressed in terms of measurements on RS(s) (e.g., SSB, CSLRS, MRS, etc.) associated to pre-activated TCI states of an LTM candidate cell, and measurements on RS(s) (e.g., SSB, CSLRS, MRS, etc.) associated to deactivated TCI states of that LTM candidate cell, as follows.

[0133] In one option, when the resource indication is included in the LTM lower layer report, it may be associated to a resource configuration which is associated to the reporting configuration in which the triggering condition which has triggered the report is configured. The resource configuration comprises a resource set may be structure as a first and a second list, wherein the first list comprises one or more SSB indexes and the second list comprises one or more LTM candidate cell identifiers (IDs), wherein the position in the list is associated to anLTM CSI resource in that LTM CSI resource configuration. For example, the instance of the IE LTM-CSI-ResourceConfig includes the following lists ltm-CSI-SSB-ResourceList-rl8 and Itm- Candi dateldLi st-r 18 : ltm-CSI-SSB-ResourceList-rl8 Itm-CandidateldList-r 18• [SSB1] [LTM Candidate cell ID 1]• [SSB2] [LTM Candidate cell ID 1]• [SSB3] [LTM Candidate cell ID 1]• [SSB4] [LTM Candidate cell ID 1]• [SSB5] [LTM Candidate cell ID 1]• [SSB1] [LTM Candidate cell ID 2]• [SSB2] [LTM Candidate cell ID 2]• [SSB3] [LTM Candidate cell ID 2]• [SSB4] [LTM Candidate cell ID 2]• [SSB5] [LTM Candidate cell ID 2]• [SSB1] [LTM Candidate cell ID 3]• [SSB2] [LTM Candidate cell ID 3]• [SSB3] [LTM Candidate cell ID 3]• [SSB4] [LTM Candidate cell ID 3]• [SSB5] [LTM Candidate cell ID 3]• [SSB1] [LTM Candidate cell ID 4]• [SSB2] [LTM Candidate cell ID 4]• [SSB3] [LTM Candidate cell ID 4]• [SSB4] [LTM Candidate cell ID 4]• [SSB5] [LTM Candidate cell ID 4]• [SSB1] [LTM Candidate cell ID 5]• [SSB2] [LTM Candidate cell ID 5]• [SSB3] [LTM Candidate cell ID 5]• [SSB4] [LTM Candidate cell ID 5]• [SSB5] [LTM Candidate cell ID 5]

[0134] In the example above, a resource indicator is associated to a position in the list(s) in which a resource is included. Each LTM CSI resource in the LTM CSI resource configuration (in particular in a resource set) has an associated resource indicator e.g., an SSB Resource Indicator (SSBRI), wherein SSBRI k (k > 0) corresponds to the configured (k+l)-th entry of the associated [LTM-csi-SSB-ResourceList] in the corresponding [LTM-CSI-SSB-ResourceSet], For example, SSBRI 0 corresponds to the configured 1-st entry of the associated [LTM-csi- SSB-ResourceList] in the corresponding [LTM-CSI-SSB-ResourceSet], i.e., the pair [SSB1], [LTM Candidate cell ID 1]; SSBRI 1 corresponds to the configured 2-nd entry i.e., the pair [SSB2], [LTM Candidate cell ID 1], etc.

[0135] The LTM lower layer report (e.g., CSI measurement report) which is being triggered (which may also be called a CSI report, or CSI report for LI / L2 -triggered mobility, or LI measurement report or LI measurement report for LTM, or L2 measurement report) comprises one or more resource indication(s), each associated to an LTM candidate cell identifier and a RSidentifier of that LTM candidate cell e.g., an SSBRI associated to an LTM candidate cell ID and an SSB Index of the LTM candidate cell associated to the LTM candidate cell ID. When the UE includes an LTM candidate cell to be included in an LTM CSI measurement report the UE includes an SSBRI associated to the selected LTM candidate cell. Taking the previous example, including LTM Candidate cell whose LTM candidate cell ID =2 means that the UE includes SSBRI 5 and / or SSBRI 6 and / or SSBRI 7 and / or SSBRI 8 and / or SSBRI 9, since:• [LTM Candidate cell ID 2]• [LTM Candidate cell ID 2]• [LTM Candidate cell ID 2]• [LTM Candidate cell ID 2]•[LTM Candidate cell ID 2]

[0136] The LTM lower layer report (e.g., CSI measurement report) which is being triggered (which may also be called a CSI report, or CSI report for LI / L2 -triggered mobility) may also comprise measurement information associated to resources which is included in the report, for example, measurement information associated to an SSBRI, such as one or more of the following:Layer 1 Reference Signal Received Power (Ll-RSRP)- Differential Ll-RSRPLayer 1 reference signal received quality (Ll-RSRQ) Differential LI -RSRQ- Layer 1 SINR (LI -SINR)- Differential LI -SINRSS reference signal received power (SS-RSRP)SS reference signal received quality (SS-RSRQ)SS signal-to-noise and interference ratio (SS-SINR)

[0137] In one example, for Ll-RSRP reporting, if the higher layer parameters [noOfReportedCells] and [noOfReportedRSPerCell] are both configured to be one, the reported Ll-RSRP value is defined by a 7-bit value in the range [-140, -44] dBm with IdB step size, or if any of the higher layer parameters [noOfReportedCells] and [noOfReportedRSPerCell] is configured to be larger than one, the UE uses differential Ll-RSRP based reporting for the LTM CSI resources whicha the UE selects to be included in the LTM CSI measurement report, where the largest measured value of Ll-RSRP is quantized to a 7-bit value in the range [-140, -44] dBm with IdB step size, and the differential Ll-RSRP is quantized to a 4-bit value. The differential Ll-RSRP value is computed with 2 dB step size with a reference to the largest measured Ll-RSRP value which is part of the same Ll-RSRP reporting instance.

[0138] SS reference signal received power (SS-RSRP), for example, maybe be defined as the linear average over the power contributions (in [W]) of the resource elements that carry secondary synchronization signals. The measurement time resource(s) for SS-RSRP areconfined within SS / PBCH Block Measurement Time Configuration (SMTC) window duration. If SS-RSRP is used for Ll-RSRP as configured by reporting configurations as defined in TS 38.214, the measurement time resources(s) restriction by SMTC window duration is not applicable.

[0139] For SS-RSRP determination demodulation reference signals for physical broadcast channel (PBCH) and, if indicated by higher layers, CSI reference signals in addition to secondary synchronization signals may be used. SS-RSRP using demodulation reference signal for PBCH or CSI reference signal shall be measured by linear averaging over the power contributions of the resource elements that carry corresponding reference signals taking into account power scaling for the reference signals as defined in TS 38.213. If SS-RSRP is not used for Ll-RSRP, the additional use of CSI reference signals for SS-RSRP determination is not applicable.

[0140] SS-RSRP shall be measured only among the reference signals corresponding to SS / PBCH blocks with the same SS / PBCH block index and the same physical-layer cell identity.

[0141] If SS-RSRP is not used for Ll-RSRP and higher-layers indicate certain SS / PBCH blocks for performing SS-RSRP measurements, then SS-RSRP is measured only from the indicated set of SS / PBCH block(s).

[0142] For frequency range 1, the reference point for the SS-RSRP shall be the antenna connector of the UE. For frequency range 2, SS-RSRP shall be measured based on the combined signal from antenna elements corresponding to a given receiver branch. For frequency range 1 and 2, if receiver diversity is in use by the UE, the reported SS-RSRP value shall not be lower than the corresponding SS-RSRP of any of the individual receiver branches.

[0143] The number of resource elements within the measurement period that are used by theUE to determine SS-RSRP is left up to the UE implementation with the limitation that corresponding measurement accuracy requirements have to be fulfilled.The power per resource element is determined from the energy received during the useful part of the symbol, excluding the CP.When the UE selects the LTM candidate cell(s) and respective RSs (e.g., SSB(s)) to include in the LTM CSI measurement report, the UE includes an SSBRI associated to a selected LTM CSI resource (i.e. pair SSB index, LTM candidate cell ID), and a measurement information associated (e.g., Ll-RSRP and / or differential Ll-RSRP), in the following mapping order:

[0144] FIG. 6 illustrates an example of a mapping order of CSI fields of one report for SSBRI / RSRP reporting for LTM. FIG. 7 illustrates an example of a bitwidth for SSBRI, RSRP, differential RSRP to be included in an LTM CSI measurement report, where ^SSBis theconfigured number of SS / PBCH blocks (SSBs) in the corresponding LTM CSI resource configuration (e.g., within a resource set) for reporting an RSRP (E.g., 'ssb-Index-RSRP'.).

[0145] Second variant: comparison of cell measurements

[0146] In a set of embodiments, the UE triggers of a lower layer report when the cell quality (e.g., cell based RSRP) of an LTM candidate cell, in a different frequency as the serving cell, becomes better than threshold.

[0147] There are different options for defining a cell quality to be used by the UE as input to the triggering condition, such as:- The cell quality of a cell may correspond to a cell measurement result such as cell-based RSRP, cell based RSRQ, cell based SINR. The measurements may be performed on one or more Reference Signals (RS(s)) transmitted in different spatial directi on(s) (e.g., beams), such as SSB(s) or CSLRS(s).- The cell quality of the inter-frequency LTM candidate cell may corresponds to the highest beam measurement quantity (e.g., highest RSRP, or highest LI RSRP) among other beams of the LTM candidate cell;- The cell quality of an LTM Candidate Cell may correspond to the beam measurement quantity of the beam (or RS) associated to a TCI state of the LTM Candidate Cell which is activated; o In one option, when the LTM Candidate Cell has a single TCI state activated, the UE considers the cell quality as the quality of the beam associated to that activated TCI State. For example, let us assume that the LTM Candidate Cell has TCI state activated with configured QCL source [SSB2], Then, the UE considers as cell quality the beam quality of SSB2. o In one option, when the LTM Candidate Cell has multiple TCI states activated, one option is to consider the cell quality as the highest measurement quantity among the beams associated to activated TCI States. For example, let us assume that the LTM Candidate Cell has 3 TCI states activated, with configured QCL sources [SSB2], [SSB5], [SSB7] wherein the SSB with the highest LI -RSRP is of SSB5. Then, the UE considers the cell quality as the quality of SSB5.- The cell quality of an LTM Candidate Cell may correspond to an average of the highest “K” beam measurements of the LTM Candidate Cell. o For example, the cell quality may be the linear power scale average of the highest beam measurement quantity values above a threshold (e.g., absThreshSS- BlocksConsolidation) where the total number of averaged beams shall not exceed “N” (e.g., nrofSS-BlocksToAverage).- The cell quality of an LTM candidate cell may correspond to an average of the “K” beam measurements associated to the “K" activated candidate TCI States of the LTM Candidate cell. o In one option, the “K” beams are a subset of all the total beam which measurement is above a threshold o In one option, the average of the “K” beam measurements is over a defined time window.- The cell quality of the LTM candidate cell may correspond to any of what is described above, but considering beams which belong to a PCell, PSCell, or SCell(s) (or any permutation of these).

[0148] Parameters for cell quality derivation (CQD)

[0149] In a set of embodiments, the UE performs cell quality derivation of an interfrequency LTM Candidate cell to be used as input to a triggering condition for triggering an LTM lower layer report, based on one or more parameters which the UE obtains e.g., upon reception of a configuration in an RRC message, such as an RRC Reconfiguration message. These parameters may be called here Cell Quality Derivation (CQD) parameters, and includes one or more of:- A “CQD threshold” for determining beams to be averaged for CQD (this is not the same configuration as the threshold which defines the event). When the CQD threshold is configured, the UE derives a cell measurement results as the linear power scale average of the highest beam measurement quantity values above the threshold where the total number of averaged beams shall not exceed a value N. o In one option, there is a threshold value per measurement quantity e.g., one for RSRP, one for RSRQ, one for SINR. o In one option, there is a threshold value per RS type e.g., one for SSB measurements, one for CSI-RS measurements, one for MRSs, etc.- A value “N” for determining the number of beams to be averaged for CQD. The UE derives a cell measurement results as the linear power scale average of the highest beam measurement quantity values above a threshold where the total number of averaged beams shall not exceed the value “N”.- A time window “T” for determining over which period of time the beams should be averaged.- Offsets;

[0150] The CQD parameters for an inter-frequency LTM candidate cell may be configured in a measurement object associated to the SSB frequency of the LTM Candidate cell (e.g., same as indicated in the LTM Configuration for that candidate). This option implies that the UE receives a measurement object (e.g., IE MeasObjectNR) associated to an inter-frequency LTM Candidate cell which needs to be measured to be used as input to a triggering condition for LTM reporting.

[0151] The CQD parameters for the inter-frequency LTM Candidate cell may be configured in the LTM Configuration for that LTM Candidate cell (e.g., not the configuration to be applied upon execution, but the configuration to be applied upon reception).

[0152] The QCD parameters for an inter-frequency LTM Candidate Cell may be configured in a resource configuration, associated to the reporting configuration associated to the triggering condition of the LTM reporting.

[0153] Resource Configuration and reporting configuration

[0154] According to the method the UE may receive an RRC message for configuring one or more parameters associated to the triggering conditions (which may also be called an event or entering condition associated to the event). The RRC message (e.g., RRC Reconfiguration) may include a reporting configuration (e.g., LTM-CSI-ReportConfig) and an association resourceconfiguration (e.g., LTM-CSI-ResourceConfig). Upon receiving the one or more parameters the UE evaluates the fulfillment of the triggering condition.

[0155] The reporting configuration may indicate an identifier (e.g., event ID) so that when the UE receives the configuration the UE determines that the configuration is for the event whose condition is defined as above i.e. an LTM lower layer report when the cell quality of the LTM candidate cell LTM candidate cell (e.g., highest LI RSRP), in a different frequency as the serving cell, becomes better than threshold.

[0156] The reporting configuration may indicate an identifier of a resource configuration (e.g., LTM-CSI-ReportConfigld, included in the reporting configuration), which indicates one or more LTM Candidate Cells to be possibly considered as input for the condition associated to the event. Thus, the UE determines the LTM Candidate Cells within the resource configuration which are considered as input to the events. In other words, even when the UE is configured with more LTM Candidate Cells which may be detected by the UE, these are not considered as applicable cells to be used as input to the events unless they are included in the resource configuration.

[0157] The reporting configuration may indicate one or more parameters associated to the event such as:- a trigger quantity, indicating what is the quantity to be measured and used as input to the triggering condition e.g., RSRP, RSRQ, SINR, LI RSRP, etc.- a threshold value, associated to the event definition e.g., in terms of dBs or dBm;- one or more reporting quantities, indicating what additional quantities the UE is meant to measure and / or report, in addition to the trigger quantity.- a time to trigger value, which indicates how long since the condition has been fulfilled the UE needs to way before sending the measurement report.- an LTM candidate cell ID, which indicate to which LTM candidate configuration the event applies- a reference signal type (e.g., SSB or CSLRS)- an indication of an associated resource configuration (e.g., resource configuration identifier)- a reporting configuration identifier

[0158] The reporting configuration may indicate an identifier of a resource configuration (e.g., LTM-CSI-ReportConfigld, included in the reporting configuration), which indicates one or more SSB(s) (or other RSs e.g., CSLRS resources, MRS(s), etc.) per one or more associated LTM Candidate cell(s), to be possibly considered as input for CQD, which is input to the triggering condition associated to the resource configuration. Thus, the UE determines the SSB(s) within the resource configuration to be considered as input to the CQD e.g., the SSBs of the LTM Candidate Cell(s) from which the highest measurement of a beam is taken, or beams whose measurement quantities are to be averaged. In other words, even when an inter-frequencyLTM Candidate Cell has more SSBs detected by the UE, these are not considered for CQD, to be used as input to the events unless they are included in the resource configuration.

[0159] In one option, the candidate cells or SSBs to be considered may be explicitly indicated by the NW in the report configuration. One example this may be a simple indication like consider all candidate cells or only the cells with TCI states activated or the cells with NO TCI states activated. This can be indicated to UE in the report configuration as following. ItmCandidatesForEventEvaluation ENUMERATED {All LTM candidates, LTM candidates with TCI state activated, LTM candidates with NO TCI state activated, Spare}

[0160] For example, based on intended usage of the event by the NW, ItmCandidatesForEventEvaluation can be configured appropriately by NW. If the NW intend to use the event for selecting the cells for DL and UL pre-synchronization, NW may indicate above field as LTM candidates with NO TCI state activate. If the NW intend to use the event for cell switch for load balancing NW can indicate LTM candidates with TCI state activated and so on.

[0161] For example, let us assume an instance of the IE LTM-CSI-ResourceConfig-rl8 (having an associated identifier e.g., ltm-CSI-ResourceConfigId-rl8) and being grouped in as a resource set (e.g., in the IE LTM-CSI-SSB-ResourceSet-rl8), wherein the resource set may be structure as a first and a second list, wherein the first list comprises one or more SSB indexes and the second list comprises one or more LTM candidate cell identifiers (IDs), wherein the position in the list is associated to an LTM CSI resource in that LTM CSI resource configuration e.g., the instance of the IE LTM-CSI-ResourceConfig includes the following lists Itm-CSLSSB- ResourceList-rl8 and ltm-CandidateIdList-r!8: ltm-CSI-SSB-ResourceList-rl8 Itm-CandidateldList-r 18• [SSB1] [LTM Candidate cell ID 1]• [SSB2] [LTM Candidate cell ID 1]• [SSB3] [LTM Candidate cell ID 1]• [SSB4] [LTM Candidate cell ID 1]• [SSB5] [LTM Candidate cell ID 1]• [SSB1] [LTM Candidate cell ID 2]• [SSB2] [LTM Candidate cell ID 2]• [SSB3] [LTM Candidate cell ID 2]• [SSB4] [LTM Candidate cell ID 2]• [SSB5] [LTM Candidate cell ID 2]• [SSB1] [LTM Candidate cell ID 3]• [SSB2] [LTM Candidate cell ID 3]• [SSB3] [LTM Candidate cell ID 3]• [SSB4] [LTM Candidate cell ID 3]• [SSB5] [LTM Candidate cell ID 3]• [SSB1] [LTM Candidate cell ID 4]• [SSB2] [LTM Candidate cell ID 4]• [SSB3] [LTM Candidate cell ID 4]• [SSB4] [LTM Candidate cell ID 4]• [SSB5] [LTM Candidate cell ID 4]• [SSB1] [LTM Candidate cell ID 5]• [SSB2] [LTM Candidate cell ID 5]• [SSB3] [LTM Candidate cell ID 5]• [SSB4] [LTM Candidate cell ID 5]• [SSB5] [LTM Candidate cell ID 5]

[0162] Thus, even when the UE has other LTM Candidate cells configured, the UE monitors the triggering condition associated to that resource configuration the LTM Candidate cells [LTM Candidate cell ID 1], [LTM Candidate cell ID 2], [LTM Candidate cell ID 3], [LTM Candidate cell ID 4],

[0163] And, even when the UE has other SSBs per LTM Candidate cells which may be detected, the UE performs CQD the triggering condition associated to that resource configuration the [SSB1], [SSB2], [SSB3], [SSB4], [SSB5] of each LTM candidate cell.

[0164] In this example, LTM Candidate cells with ID 2 and ID 4 are the inter-frequency LTM Candidate Cell(s). Then, only LTM Candidate cells with ID 2 and ID 4 are applicable when that resource configuration is indicated in a reporting configuration configuring the event in which the cell quality of the LTM candidate cell LTM candidate cell (e.g., highest LI RSRP), in a different frequency as the serving cell, becomes better than threshold. And, even when the UE has other SSBs per LTM Candidate cells which may be detected, the UE monitors the triggering condition associated to that resource configuration the [SSB1], [SSB2], [SSB3], [SSB4], [SSB5] of the LTM candidate cell ID 2 and the [SSB1], [SSB2], [SSB3], [SSB4], [SSB5] of the LTM candidate cell ID 4.

[0165] In one option, not all SSBs of an LTM Candidate Cell which are included in the resource configuration are considered as input to CQD, but the SSBs in the resource configuration which are associated to the activated LTM candidate cell which is also in the resource configuration and / or in the SSB frequencies indicated in a command from the network.

[0166] In another option, not all SSBs of an LTM Candidate Cell which are included in the resource configuration are applicable to be considered for CQD, but the SSBs in the resource configuration which are associated to the activated TCI state(s) of the LTM candidate cell e.g., SSBs configured as QCL source of a candidate TCI state which is activated. Assuming the example above, in which [LTM Candidate cell ID 2] is activated, [SSB3], [SSB4], [SSB5] of [LTM Candidate cell ID 2] are considered for CQD of [LTM Candidate cell ID 2],

[0167] In one option, the reporting configuration is associated to an LTM candidate ID, and no explicitly SSB list is provided in a resource configuration. The UE determines the SSBs associated to the LTM Candidate ID for CQD by obtaining the TCI state configuration. TheSSBs considered as possible input for CQD are the SSBs configured as QCL source(s) in the Candidate TCI state configuration associated to the LTM candidate cell.

[0168] In a set of embodiments, the multiple LTM Candidate cell(s) fulfill the triggering condition: the cell quality of the LTM candidate cell LTM candidate cell (e.g., highest LI RSRP), in a different frequency as the serving cell, becomes better than threshold. In other words, multiple LTM Candidate cell(s) may, at a certain point in time, be better than threshold.

[0169] LTM lower layer reporting

[0170] According to the method, the UE transmits an LTM lower layer report when the triggering condition is fulfilled i.e. when the cell quality (e.g., cell based RSRP) of an LTM candidate cell becomes better than a threshold, wherein the UE includes one or more of the following in the LTM lower layer report:- Information about the best “ N beam” (or RS) of the LTM Candidate Cell whose cell quality has triggered the event, such as: o An indication of a value of the beam measurement quantity e.g., Ll-RSRP associated to the best beam or RS; o An indication of a value of a measurement quantity configured at the UE (e.g., reporting quantity(ies) configured in the LTM reporting configuration) e.g., Ll- RSRQ associated to that beam or RS; o A differential measurement quantity (e.g., differential LI RSRP) associated to the best beam (e.g., relative to a reference value) of the LTM Candidate cell; o An indication of the best beam or RS such as, a beam identifier of the best beam, an RS index (e.g., SSB index) or a resource indication, indicating the position of that best beam in the associated resource configuration, such as an SSB Resource Indicator (SSBRI), in the case of an SSB being configured as a resource; o N may be configurable or fixed quantity- Information about the best “beam” (or RS) of the Serving Cell whose cell quality has triggered the event, such as: o An indication of a value of the beam measurement quantity e.g., Ll-RSRP associated to the best beam or RS of the Serving Cell; o An indication of a value of a measurement quantity configured at the UE (e.g., reporting quantity(ies) configured in the LTM reporting configuration) e.g., Ll- RSRQ associated to that beam or RS; o A differential measurement quantity (e.g., differential LI RSRP) associated to the best beam (e.g., relative to a reference value) of the Serving Cell; o NOTE: this may be included or not in the LTM lower layer report based on a parameter included in the reporting configuration in which the trigger condition is configured. For example, when the parameter is included, the UE includes information about serving cell and / or PCell frequency.- An indication of the best beam or RS such as, a beam identifier of the best beam, an RS index (e.g., SSB index) or a resource indication, indicating the position of that best beam in the associated resource configuration, such as an SSB Resource Indicator (SSBRI), in the case of an SSB being configured as a resource;- Information about the LTM candidate cell whose cell quality has triggered the event o LTM Candidate ID e.g., encoded in fewer bits than the cell identity and associated to an LTM Candidate cell configuration, configured when LTM is configured;o Cell identifier (Cell ID) of the LTM Candidate cell which has triggered the LTM lower layer report;■ This may be a Serving cell index or SCell index depending on whether the LTM candidate cell has been configured as a PCell, PSCell, or SCell. o Physical Cell Identity (PCI) of the LTM candidate cell which has triggered the LTM lower layer report; o SSB Frequency (e.g., ARFCN of the SSB) of the LTM candidate cell which has triggered the LTM lower layer report; o Cell quality of the LTM Candidate cell e.g., cell-level RSRP, cell-level RSRQ, cell level SINR, etc.- Information about the Serving cell e.g., Pcell associated to the “best” beam and / or best SSB of the Serving cell o LTM Candidate ID e.g., encoded in fewer bits than the cell identity and associated to the current serving cell, also configured as an LTM Candidate cell configuration, configured when LTM is configured; o Cell identifier (Cell ID) of the Serving Cell which has triggered the LTM lower layer report;■ This may be a Serving cell index or SCell index depending on whether the LTM candidate cell has been configured as a PCell, PSCell, or SCell. o Physical Cell Identity (PCI) of the Serving Cell which has triggered the LTM lower layer report; o SSB Frequency (e.g., ARFCN of the SSB) of the Serving Cell which has triggered the LTM lower layer report; o Cell quality of the Serving cell e.g., cell-level RSRP, cell-level RSRQ, cell level SINR, etc. o NOTE: this may be included or not in the LTM lower layer report based on a parameter included in the reporting configuration in which the trigger condition is configured. For example, when the parameter is included, the UE includes information about serving cell and / or PCell frequency. o- An identifier associated to the measurement which is being triggered e.g., a reporting configuration identifier, and / or a resource configuration identifier, or another identifier associated to the reporting configuration identifier o An Event ID, if there are multiple events configured for one or more LTM candidate cells, but e.g., with different conditions or parameters. o Configuration ID, if one event ID is configured with multiple configuration ID. E.g., one config ID can be configured with one set of thresholds for selecting cells with TCI state activation. Other set of configuration with other set of thresholds for cell switch.- Time stamp information about the last measurement occasion for the inter-frequency neighbour cell that triggered the event. o In one example the reporting granularity of the time stamp can be in the order of number SSB periods. This can be reported in terms of number of SSB periods of the inter-frequency neighbors. For example, if the event is evaluated after the serving cell measurement (serving cell became lower than threshold after latest measurement while the neighbour cell was higher than threshold before this measurement), if the inter-frequency cell measurement was made 2 SSB period earlier than the serving cell measurement, UE reports this field as 2. o This is particularly useful for the NW to understand the T / F validity of the LTM inter-frequency candidate cell so that NW can schedule the PRACH preamble occasion as per this report.o In one example, if the inter-frequency neighbour was measured more than 160ms before the serving cell measurement that triggered the report, NW can schedule the PRACH transmission after 60ms (e.g., Yl*SSB_period, Y1 is 3 and SSB _period is 20ms). This helps NW utilize the PRACH preamble occasions effectively. o In another example, NW can configure a time threshold for the last measured occasion such as Y1 ms. In this example, UE reports 1 if UE has measured the SSB within last Y1 ms. Else UE reports 0. In one example NW may configure Y1 as 80ms. In another example NW may configure 160ms. In some other examples, Y 1 value may be a fixed value in the spec than the configurable value.

[0171] For that set of embodiments, the UE transmits the LTM lower layer report e.g., by transmitting a MAC Control Element, and / or a report over PUSCH and / or PUCCH.

[0172] The fulfillment of the triggering condition may be expressed in terms of measurements on RS(s) (e.g., SSB, CSI-RS, MRS, etc.) associated to pre-activated TCI states of an LTM candidate cell, and measurements on RS(s) (e.g., SSB, CSI-RS, MRS, etc.) associated to deactivated TCI states of that LTM candidate cell, as follows.

[0173] In one option, when the resource indication is included in the LTM lower layer report, it may be associated to a resource configuration which is associated to the reporting configuration in which the triggering condition which has triggered the report is configured. The resource configuration comprises a resource set may be structure as a first and a second list, wherein the first list comprises one or more SSB indexes and the second list comprises one or more LTM candidate cell identifiers (IDs), wherein the position in the list is associated to an LTM CSI resource in that LTM CSI resource configuration. For example, the instance of the IE LTM-CSI-ResourceConfig includes the following lists ltm-CSI-SSB-ResourceList-rl8 and Itm- Candi dateldLi st-r 18 : ltm-CSI-SSB-ResourceList-rl8 Itm-CandidateldList-r 18• [SSB1] [LTM Candidate cell ID 1]• [SSB2] [LTM Candidate cell ID 1]• [SSB3] [LTM Candidate cell ID 1]• [SSB4] [LTM Candidate cell ID 1]• [SSB5] [LTM Candidate cell ID 1]• [SSB1] [LTM Candidate cell ID 2]• [SSB2] [LTM Candidate cell ID 2]• [SSB3] [LTM Candidate cell ID 2]• [SSB4] [LTM Candidate cell ID 2]• [SSB5] [LTM Candidate cell ID 2]• [SSB1] [LTM Candidate cell ID 3]• [SSB2] [LTM Candidate cell ID 3]• [SSB3] [LTM Candidate cell ID 3]• [SSB4] [LTM Candidate cell ID 3]• [SSB5] [LTM Candidate cell ID 3]• [SSB1] [LTM Candidate cell ID 4]• [SSB2] [LTM Candidate cell ID 4]• [SSB3] [LTM Candidate cell ID 4]• [SSB4] [LTM Candidate cell ID 4]• [SSB5] [LTM Candidate cell ID 4]• [SSB1] [LTM Candidate cell ID 5]• [SSB2] [LTM Candidate cell ID 5]• [SSB3] [LTM Candidate cell ID 5]• [SSB4] [LTM Candidate cell ID 5]• [SSB5] [LTM Candidate cell ID 5]

[0174] In the example above, a resource indicator is associated to a position in the list(s) in which a resource is included. Each LTM CSI resource in the LTM CSI resource configuration (in particular in a resource set) has an associated resource indicator e.g., an SSB Resource Indicator (SSBRI), wherein SSBRI k (k > 0) corresponds to the configured (k+l)-th entry of the associated [LTM-csi-SSB-ResourceList] in the corresponding [LTM-CSI-SSB-ResourceSet], For example, SSBRI 0 corresponds to the configured 1-st entry of the associated [LTM-csi- SSB-ResourceList] in the corresponding [LTM-CSI-SSB-ResourceSet], i.e., the pair [SSB1], [LTM Candidate cell ID 1]; SSBRI 1 corresponds to the configured 2-nd entry i.e., the pair [SSB2], [LTM Candidate cell ID 1], etc.

[0175] The LTM CSI measurement report which is being triggered (which may also be called a CSI report, or CSI report for LI / L2 -triggered mobility, or LI measurement report or LI measurement report for LTM, or L2 measurement report) comprises one or more resource indication(s), each associated to an LTM candidate cell identifier and a RS identifier of that LTM candidate cell e.g., an SSBRI associated to an LTM candidate cell ID and an SSB Index of the LTM candidate cell associated to the LTM candidate cell ID. When the UE includes an LTM candidate cell to be included in an LTM CSI measurement report the UE includes an SSBRI associated to the selected LTM candidate cell. Taking the previous example, including LTM Candidate cell whose LTM candidate cell ID =2 means that the UE includes SSBRI 5 and / orSSBRI 6 and / or SSBRI 7 and / or SSBRI 8 and / or SSBRI 9, since:• [LTM Candidate cell ID 2]• [LTM Candidate cell ID 2]• [LTM Candidate cell ID 2]• [LTM Candidate cell ID 2]•[LTM Candidate cell ID 2]

[0176] An LTM CSI measurement report (which may also be called a CSI report, or CSI report for Ll / L2-triggered mobility) may also comprise measurement information associated to an LTM CSI resource which is included in the LTM CSI measurement report, for example, measurement information associated to an SSBRI, such as one or more of the following:Layer 1 Reference Signal Received Power (Ll-RSRP)- Differential Ll-RSRPLayer 1 reference signal received quality (Ll-RSRQ) Differential LI -RSRQ- Layer 1 SINR (LI -SINR)- Differential LI -SINRSS reference signal received power (SS-RSRP)SS reference signal received quality (SS-RSRQ)SS signal-to-noise and interference ratio (SS-SINR)

[0177] In one example, for Ll-RSRP reporting, if the higher layer parameters [noOfReportedCells] and [noOfReportedRSPerCell] are both configured to be one, the reported Ll-RSRP value is defined by a 7-bit value in the range [-140, -44] dBm with IdB step size, or if any of the higher layer parameters [noOfReportedCells] and [noOfReportedRSPerCell] is configured to be larger than one, the UE uses differential Ll-RSRP based reporting for the LTM CSI resources whicha the UE selects to be included in the LTM CSI measurement report, where the largest measured value of Ll-RSRP is quantized to a 7-bit value in the range [-140, -44] dBm with IdB step size, and the differential Ll-RSRP is quantized to a 4-bit value. The differential Ll-RSRP value is computed with 2 dB step size with a reference to the largest measured Ll-RSRP value which is part of the same Ll-RSRP reporting instance.

[0178] SS reference signal received power (SS-RSRP), for example, maybe be defined as the linear average over the power contributions (in [W]) of the resource elements that carry secondary synchronization signals. The measurement time resource(s) for SS-RSRP are confined within SS / PBCH Block Measurement Time Configuration (SMTC) window duration. If SS-RSRP is used for Ll-RSRP as configured by reporting configurations as defined in TS 38.214, the measurement time resources(s) restriction by SMTC window duration is not applicable.

[0179] For SS-RSRP determination demodulation reference signals for physical broadcast channel (PBCH) and, if indicated by higher layers, CSI reference signals in addition to secondary synchronization signals may be used. SS-RSRP using demodulation reference signal for PBCH or CSI reference signal shall be measured by linear averaging over the power contributions of the resource elements that carry corresponding reference signals taking into account power scaling for the reference signals as defined in TS 38.213. If SS-RSRP is not used for Ll-RSRP, the additional use of CSI reference signals for SS-RSRP determination is not applicable.

[0180] SS-RSRP shall be measured only among the reference signals corresponding to SS / PBCH blocks with the same SS / PBCH block index and the same physical-layer cell identity.

[0181] If SS-RSRP is not used for Ll-RSRP and higher-layers indicate certain SS / PBCH blocks for performing SS-RSRP measurements, then SS-RSRP is measured only from the indicated set of SS / PBCH block(s).

[0182] For frequency range 1, the reference point for the SS-RSRP shall be the antenna connector of the UE. For frequency range 2, SS-RSRP shall be measured based on the combined signal from antenna elements corresponding to a given receiver branch. For frequency range 1 and 2, if receiver diversity is in use by the UE, the reported SS-RSRP value shall not be lower than the corresponding SS-RSRP of any of the individual receiver branches.

[0183] The number of resource elements within the measurement period that are used by the UE to determine SS-RSRP is left up to the UE implementation with the limitation that corresponding measurement accuracy requirements have to be fulfilled.The power per resource element is determined from the energy received during the useful part of the symbol, excluding the CP.When the UE selects the LTM candidate cell(s) and respective RSs (e.g., SSB(s)) to include in the LTM CSI measurement report, the UE includes an SSBRI associated to a selected LTM CSI resource (i.e. pair SSB index, LTM candidate cell ID), and a measurement information associated (e.g., Ll-RSRP and / or differential Ll-RSRP), in the following mapping order:

[0184] FIG. 6 illustrates an example of a mapping order of CSI fields of one report for SSBRI / RSRP reporting for LTM.

[0185] FIG. 7 illustrates an example of a bitwidth for SSBRI, RSRP, differential RSRP to be included in an LTM CSI measurement report, whereSSBis the configured number of SS / PBCH blocks (SSBs) in the corresponding LTM CSI resource configuration (e.g., within a resource set) for reporting an RSRP (E.g., 'ssb-Index-RSRP'.).

[0186] Further details on Applicable cells and applicable beams

[0187] In a set of embodiments, the UE monitors the fulfillment of triggering conditions (associated to a reporting configuration) for LTM Candidate Cell(s) which are inter-frequency LTM Candidate cell. When an LTM Candidate cell is not an inter-frequency LTM candidate cell, that LTM Candidate Cell is not monitored for the fulfillment of the triggering condition.

[0188] In a set of embodiments, the UE monitors the fulfillment of triggering conditions (associated to a reporting configuration) for LTM Candidate Cell(s) for which there is at least one candidate TCI State activated (or pre-activated). When an LTM Candidate cell does not have a candidate TCI state activated, that LTM Candidate Cell is not monitored for the fulfillment of the triggering condition; when a TCI State of an LTM Candidate cell is activated, the UE evaluates the triggering condition; when a TCI State of an LTM Candidate cell is deactivated, the UE stops evaluating the triggering condition. One benefit is that the UE reduces the amount of LTM Candidate cells for which it needs to evaluate the triggering conditions, which may reduce the number of inter-frequency measurements the UE needs to perform and report. In other words, in this case we may say that the applicable LTM Candidate cells are theLTM Candidate cells configured for which the UE has at least one TCI state activated. Notice that these may be the inter-frequency LTM candidate cell(s) associated to a threshold2 value acceptable for an inter-frequency LTM Cell Switch.

[0189] One could consider that the reception of the command from the network for preactivating a TCI state of an LTM candidate cell which does not have any activated TCI state (e.g., reception of a “Candidate Cell TCI States Activation / Deactivation MAC CE MAC CE”) leads the UE to initiate the evaluating of the fulfillment of the condition.

[0190] For example, when the LTM resource configuration associated to the LTM reporting configuration for the event includes one or more LTM Candidate Cell(s) (e.g., LTM Candidate IDs in the resource configuration), the UE considers as applicable cells (i.e. cells to be evaluated for the triggering conditions, to be compared with the serving cell) the subset of inter-frequency LTM Candidate cell(s) among these for which at least one candidate TCI state has been activated, e.g., which may be a single LTM Candidate cell. A candidate TCI state of an interfrequency LTM Candidate cell is configured at the UE e.g., when the UE is configured with the candidate, and, the UE may further receive a command to pre-activate a TCI state of an LTM candidate cell before an LTM Cell switch command, so that in response to the command to activate a candidate TCI state of the LTM Candidate the UE evaluates the fulfillment of the triggering condition for the LTM Candidate Cell, and does not need to evaluate the triggering conditions for the other LTM Candidate cells in the LTM Resource configuration which do not have an activated candidate TCI State.

[0191] In a set of embodiments, the UE monitors the fulfillment of triggering conditions (associated to a reporting configuration) for beams (e.g., SSBs) of LTM Candidate Cell(s) associated to candidate TCI State activated (or pre-activated). A beam measurement (of a beam of an LTM Candidate Cell) is considered as input to the triggering condition when the beam is associated to a candidate TCI state which is activated, e.g., when the beam (e.g., SSB) of the LTM candidate cell is configured as QCL source of the candidate TCI state which is activated. When a beam of an LTM Candidate cell does not have an associated candidate TCI state activated, that beam is not monitored for the fulfillment of the triggering condition; when a TCI State of an LTM Candidate cell is activated, the UE evaluates the triggering condition for the associated beam; when a TCI State of an LTM Candidate cell is deactivated, the UE stops evaluating the triggering condition for the beam associated to that TCI state. One benefit is that the UE reduces the amount of beams of an LTM Candidate cell for which it needs to evaluate the triggering conditions, which may reduce the number of measurements the UE needs to perform and report. This is especially important in the case these beams are of inter-frequency neighbour cells, more costly to be measured. In other words, in this case we may say that theapplicable beams of an LTM Candidate cell are the beams of the LTM Candidate cells configured for which the UE has associated TCI states activated.

[0192] One could consider that the reception of the command from the network for preactivating a TCI state of an LTM candidate cell which does not have any activated TCI state (e.g., reception of a “Candidate Cell TCI States Activation / Deactivation MAC CE MAC CE”) leads the UE to initiate the evaluating of the fulfillment of the condition.

[0193] For example, when the LTM resource configuration associated to the LTM reporting configuration for the event includes one or more SSBs of an LTM Candidate Cell (e.g., SSB indexes in the resource configuration), the UE considers as applicable beams / SSBs (i.e. beams / SSBs to be evaluated for the triggering conditions, to be compared with the best beam / best SSB of the serving cell) the subset of beams / SSBs among these which have the associated candidate TCI state activated, e.g., which may be a single SSB of the LTM Candidate cell. A candidate TCI state of an LTM Candidate cell is configured at the UE e.g., when the UE is configured with the candidate, and, the UE may further receive a command to pre-activate a TCI state of an LTM candidate cell before an LTM Cell switch command, so that in response to the command to activate a candidate TCI state (associated to a beam / SSB-X) of the LTM Candidate the UE evaluates the fulfillment of the triggering condition for the SSB-X of the LTM Candidate Cell, and does not need to evaluate the triggering conditions for the other beams of the LTM Candidate cell in the LTM Resource configuration which do not have an activated candidate TCI State.

[0194] In a set of embodiments, the UE monitors the fulfillment of triggering conditions (associated to a reporting configuration) for LTM Candidate Cell(s) for which the UE has performed an Early Uplink sync procedure. When an LTM Candidate cell is a cell for which the UE has not performed an early UL sync procedure, that LTM Candidate Cell is not monitored for the fulfillment of the triggering condition; when the UE triggers an Early UL sync procedure, the UE evaluates the triggering condition for that LTM Candidate cell; when the UL sync for an LTM Candidate cell is determined to be invalid (e.g., indication from the network and / or expiry of a Time Alignment timer), the UE stops evaluating the triggering condition. One benefit is that the UE reduces the amount of LTM Candidate cells for which it needs to evaluate the triggering conditions, which may reduce the number of measurements the UE needs to perform and report. In other words, in this case we may say that the applicable LTM Candidate cells are the LTM Candidate cells configured for which the UE has a chance to perform an LTM Cell Switch without the need of a random access procedure.

[0195] One could consider that the reception of the command from the network for triggering the Early UL sync, a Physical Downlink Control Channel (PDCCH) order indicatingan LTM candidate cell, leads the UE to initiate the evaluating of the fulfillment of the condition for the indicated LTM Candidate Cell. Or, alternatively, the transmission of a preamble to the LTM Candidate cell indicated in the PDCCH order. Or, alternatively, the transmission of a preamble to the LTM Candidate cell indicated in the PDCCH order and the absence of another PDCCH order indicating a re-transmission of an attempt.

[0196] For example, when the LTM resource configuration associated to the LTM reporting configuration for the event includes one or more LTM Candidate Cell(s) (e.g., LTM Candidate IDs in the resource configuration), the UE considers as applicable cells (i.e. cells to be evaluated for the triggering conditions, to be compared with the serving cell) the subset of LTM Candidate cell(s) among these for which Early UL sync has been performed by the UE e.g., which may be a single LTM Candidate cell.

[0197] In a set of embodiments, the UE monitors the fulfillment of triggering conditions (associated to a reporting configuration) for beams (e.g., SSBs) of LTM Candidate Cell(s) which have been indicated during Early UL sync. A beam measurement (of a beam of an LTM Candidate Cell) is considered as input to the triggering condition when the beam (e.g., SSB) has been indicated in a PDCCH order triggering an Early UL sync procedure, leading to the selection of a Random Access Resource of an LTM Candidate cell associated to the indicated beam (SSB). When a beam of an LTM Candidate cell has not been indicated in the PDCCH order triggering the Early UL sync, that beam is not monitored for the fulfillment of the triggering condition; when a beam (SSB index) is indicated in the PDCCH triggering Early UL sync, the UE evaluates the triggering condition for the associated beam; when the Early UL sync with a beam becomes invalid (e.g., expiry of the Time Alignment timer for an LTM candidate cell and / or beam), the UE stops evaluating the triggering condition for the beam associated to that TCI state. One benefit is that the UE reduces the amount of beams of an LTM Candidate cell for which it needs to evaluate the triggering conditions, which may reduce the number of measurements the UE needs to perform and report. In other words, in this case we may say that the applicable beams of an LTM Candidate cell are the beams which have been indicated to the UE in PDCCH orders triggering Early UL sync.

[0198] One could consider that the reception of the command from the network for triggering Early UL sync (e.g., PDCCH order indicating an LTM candidate cell and an associated beam / SSB index) which leads the UE to initiate the evaluating of the fulfillment of the condition.

[0199] For example, when the LTM resource configuration associated to the LTM reporting configuration for the event includes one or more SSBs of an LTM Candidate Cell (e.g., SSB indexes in the resource configuration), the UE considers as applicable beams / SSBs (i.e. beams / SSBs to be evaluated for the triggering conditions, to be compared with the best beam / best SSB of the serving cell) the subset of beams / SSBs among these which have been indicated in the command for triggering Early UL sync.

[0200] In a set of embodiments, the UE monitors the fulfillment of triggering conditions (associated to a reporting configuration) for LTM Candidate Cell(s) for which there is at least one candidate TCI State activated (or pre-activated) and for which early UL sync has been triggered.

[0201] In a set of embodiments, the UE monitors the fulfillment of triggering conditions (associated to a reporting configuration) for beams (e.g., SSBs) of LTM Candidate Cell(s) associated to candidate TCI State activated (or pre-activated) and which have been indicated during Early UL sync.

[0202] In one embodiment, the UE triggers an LTM lower layer report when the LI RSRP of an SSB of the LTM candidate cell, which is configured as Quasi-Co-Location (QCL) source of a activated TCI state of the LTM candidate cell, becomes better than threhsold2 AND the LI RSRP of the SSB (e.g., SS-RSRP) of the serving cell configured as QCL source of the activated TCI state of the serving cell is worse than thresholdl.

[0203] Operations of a communication device 1300 (implemented using the structure of FIG. 13) will now be discussed with reference to the flow chart of FIG. 8 according to some embodiments of inventive concepts. For example, modules may be stored in memory 1310 of FIG. 13, and these modules may provide instructions so that when the instructions of a module are executed by respective communication device processing circuitry 1302, communication device 1300 performs respective operations of the flow chart.

[0204] At block 810, processing circuity 1302 receives, via communication interface 1312, an indication of configuration information. In some embodiments, the configuration information configures the communication device to transmit the LTM lower layer report in response to the triggering condition being met.

[0205] In additional or alternative embodiments, receiving the indication of the configuration information includes receiving a reporting configuration associated to a resource configuration, the resource configuration indicating at least one resource to be measured and used as input to the triggering condition.

[0206] At block 820, processing circuitry 1302 determines a first measurement. In some embodiments, the first measurement is associated with the LTM candidate cell. In additional or alternative embodiments, determining the first measurement includes determining a measurement of a beam of the LTM candidate cell. In some examples, the beam can be a RS, CSLRS, SSB, or SSRI. In additional or alternative embodiments, determining the firstmeasurement of the beam of the LTM candidate cell includes determining at least one of: the beam; a reference signal identifier, ID; and a measurement quantity value.

[0207] In additional or alternative embodiments, determining the first measurement includes determining an indication of a best beam of the LTM candidate cell.

[0208] In additional or alternative embodiments, determining the first measurement includes determining a cell level measurement of the LTM candidate cell.

[0209] In additional or alternative embodiments, determining the measurement includes determining a cell quality of the LTM candidate cell.

[0210] In some examples, the LTM candidate cell is an inter-frequency neighbor.

[0211] In additional or alternative examples, a center frequency of the LTM candidate cell is different from a center frequency of a serving cell, and / or a subcarrier spacing of a synchronization signal block of the LTM candidate cell is different from a subcarrier spacing of a synchronization signal block of the serving cell.

[0212] At block 830, processing circuitry 1302 determines a second measurement. In some embodiments, the second measurement is associated with a serving cell for which a TCI state is activated.

[0213] In additional or alternative embodiments, determining the second measurement includes determining an indication of a best beam of the serving cell. In some examples, the best beam of the serving cell corresponds to at least one of: a beam associated with the TCI state that is activated in the serving cell; a synchronization signal block, SSB, configured as a quasicollocated, QCL, source of the TCI state that is activated in the serving cell;a beam associated with a the highest measurement quantity among beams associated to the TCI state that is activated; and a beam that the communication device is considering for physical downlink control channel, PDCCH, receptions.

[0214] In additional or alternative embodiments, determining the second measurement includes at least one of: determining a cell level measurement of the serving cell, and determining a cell quality of the serving cell.

[0215] In additional or alternative embodiments, the serving cell for which the TCI state is activated comprises at least one of: a special cell, SpCell; a primary cell of a master cell group, MCG; a primary cell of a secondary cell group, SCG; a secondary cell of the MCG; and a secondary cell of the SCG.

[0216] In additional or alternative embodiments, a center frequency of the LTM candidate cell is different from a center frequency of the serving cell, and / or a subcarrier spacing of a synchronization signal block of the LTM candidate cell is different from a subcarrier spacing of a synchronization signal block of the serving cell.

[0217] In additional or alternative embodiments, a frequency range of the LTM candidate cell is different than a frequency range of the serving cell. A frequency band of the LTM candidate cell is different than a frequency band of the serving cell. The frequency band of the LTM candidate cell is associated with a first radio access technology, RAT, and the frequency band of the serving cell is associated with a second RAT that is different from the first RAT.

[0218] At block 840, processing circuitry 1302 determines that a triggering condition is met. In some embodiments, determining that the triggering condition is met includes determining that the triggering condition is met based on the first measurement associated with a LTM candidate cell. In additional or alternative embodiments, determining that the triggering condition is met includes comparing the first measurement to a threshold value.

[0219] In additional or alternative embodiments, determining that the triggering condition is met includes determining that the first measurement is better than a first threshold and that the second measurement is worse than a second threshold.

[0220] At block 850, processing circuitry 1302 transmits, via communication interface 1312, a LTM lower layer measurement report. In some embodiments, the communication device transmits the LTM lower layer measurement report in response to determining that the triggering condition is met. In additional or alternative embodiments, transmitting the LTM lower layer report includes transmitting at least one of: an indication of the first measurement; an indication of a second measurement associated with a serving cell; an indication of the LTM candidate cell associated with the first measurement; and an indication of the serving cell associated with the second measurement.

[0221] At block 860, processing circuitry 1302 receives, via communication interface 1312, a command. In some embodiments, the TCI state activated within the LTM candidate cell is a second TCI state. In some examples, the command includes a command indicating an activation of a first TCI state within the LTM candidate cell. In additional or alternative examples, the command further indicates a deactivation of the second TCI state within the LTM candidate cell. In additional or alternative examples, receiving the command includes receiving a LTM cell switching command, and the first TCI state is different than the second TCI state.

[0222] In additional or alternative embodiments, receiving the command includes receiving a TCI state activation command or a TCI state deactivation command.

[0223] In additional or alternative embodiments, receiving the command comprises receiving a request to trigger an early uplink synchronization procedure.

[0224] Various operations from the flow chart of FIG. 8 may be optional with respect to some embodiments of communication devices and related methods.

[0225] Operations of a network node 1300 (implemented using the structure of FIG. 14) will now be discussed with reference to the flow chart of FIG. 9 according to some embodiments of inventive concepts. For example, modules may be stored in memory 1404 of FIG. 14, and these modules may provide instructions so that when the instructions of a module are executed by respective network node processing circuitry 1402, network node 1400 performs respective operations of the flow chart.

[0226] At block 905, processing circuitry 1402 determines the configuration information based on a load balancing function.

[0227] At block 910, processing circuitry 1402 transmits, via communication interface 1406, an indication of configuration information. In some embodiments, the configuration information configures the communication device to transmit a LTM lower layer report in response to fulfillment of a triggering condition. The triggering condition can be based on comparing a measurement to a threshold value, the measurement being associated with a LTM candidate cell. In some examples, the LTM candidate cell is an inter-frequency neighbor.

[0228] At block 920, processing circuitry 1402 receives, via communication interface 1406, a LTM lower layer measurement report.

[0229] At block 930, processing circuitry 1402 transmits, via communication interface 1406, a command. In some embodiments, the command includes transmitting at least one of: an LTM Cell switch command; a TCI activation command for an LTM Candidate Cell; and a command for triggering an Early Uplink sync procedure.

[0230] Various operations from the flow chart of FIG. 9 may be optional with respect to some embodiments of communication devices and related methods.

[0231] Example Embodiments are provided below.

[0232] Embodiment Al . A method at a UE comprising: transmitting an LTM lower layer report upon fulfillment of a triggering condition, wherein the triggering condition comprises a measurement associated to an LTM candidate cell becomes better than absolute threshold.

[0233] Embodiment A2. A method of Al and all, wherein the LTM candidate cell is an inter-frequency neighbour cell and / or an inter-frequency LTM candidate cell.

[0234] Embodiment A3. A method of Al and all, wherein the LTM candidate cell is in an SSB frequency different than the SSB frequency of the serving cell (e.g., PCell) and / or the LTM candidate cell has a subcarrier spacing different than the subcarrier spacing of the serving cell (e.g., PCell).

[0235] Embodiment A4. A method of Al and all, wherein the LTM candidate cell is in an SSB center frequency different than the SSB center frequency of the serving cell (e.g., PCell)and / or the LTM candidate cell has a subcarrier spacing different than the subcarrier spacing of the serving cell (e.g., PCell).

[0236] Embodiment A6. A method of Al and all, wherein the LTM lower layer report may include measurements associated with a serving cell and / or a measurement associated with an LTM candidate cell.

[0237] Embodiment A6b. A method of Al and all, wherein the measurement associated to an LTM Candidate cell comprises a beam (or RS) measurement of a beam of the LTM Candidate cell.

[0238] Embodiment A6c. A method of Al and all, where a measurement associated with an LTM candidate cell comprises a beam or RS identifier and a measurement quantity value.

[0239] Embodiment A6d. A method of A6c, where the measurement quantity value is a Ll- RSRP value, a Ll-SINR value or a Ll-RSRQ value.

[0240] Embodiment A7. A method of Al and all, wherein the triggering condition comprises: a “best” beam of the LTM Candidate cell (e.g., measurement on the “best” beam of the LTM Candidate cell) becomes better than absolute threshold.

[0241] Embodiment A8. A method of Al and all, wherein the measurement associated to an LTM Candidate cell comprises a cell level measurement of the LTM Candidate cell which is inter-frequency neighbour to serving cell.

[0242] Embodiment A9. A method of Al and all wherein the triggering condition comprises: the cell quality of the LTM Candidate cell becomes better than absolute threshold.

[0243] Embodiment A10. A method of Al and all, wherein in response to transmitting the LTM lower layer report, the UE receiving an LTM Cell Switch Command indicating an LTM Candidate Cell (which is an inter-frequency neighbour cell) and a TCI state which is to be activated in the LTM Candidate Cell which becomes the target cell or the UE receiving a release with redirect command indicating an SSB frequency which is different than the SSB frequency of the PCell.

[0244] Embodiment Al 1. A method of Al and all, wherein the LTM Cell Switch Command indicates an LTM Candidate Cell (which is an inter-frequency cell) included in the LTM lower layer report and a TCI state (e.g., TCI State ID) associated to a beam and / or a RS and / or an SSB indicated in the LTM lower layer report.

[0245] Embodiment A12. A method of Al and all, in response to transmitting the LTM lower layer report, the UE receiving a TCI activation command for an LTM Candidate Cell (e.g., Candidate Cell TCI States Activation / Deactivation) indicating an LTM Candidate Cell (which is an inter-frequency neighbour cell) and a TCI state which is to be activated in the LTM Candidate Cell, as a preparation for an inter-frequency LTM Cell Switch for load balancing.

[0246] Embodiment A12b. A method of Al and all, where the UE, in response to transmitting the LTM lower layer report, receives a secondary cell (SCell) activation command.

[0247] Embodiment A12c. A method of A12b and all, where the SCell that is activated is associated with the LTM candidate cell.

[0248] Embodiment A12d. A method of A12b or A12c, where the activation is performed by MAC CE.

[0249] Embodiment Al 3. A method of Al and all, in response to the TCI activation command for an LTM Candidate Cell (e.g., Candidate Cell TCI States Activation / Deactivation) indicating the LTM Candidate Cell (which is an inter-frequency neighbour cell) and the TCI state, and in response to the TCI state activation command, performing the TCI state(s) activation and acquiring T / F synchronization for the RS associated with TCI state in the LTM candidate cell as a preparation for an inter-frequency LTM Cell Switch for load balancing.

[0250] Embodiment A14. A method of Al and all, wherein in response to transmitting the LTM lower layer report, the UE receives the TCI activation command for an LTM Candidate Cell (e.g., Candidate Cell TCI States Activation / Deactivation) indicating the LTM Candidate Cell (which is an inter-frequency neighbour cell) and a TCI state which is to be activated in the LTM Candidate Cell, before the UE receives an LTM Cell Switch command for an LTM Candidate Cell, as a preparation for an inter-frequency LTM Cell Switch for load balancing.

[0251] Embodiment Al 5. A method of Al and all, wherein the UE receives the TCI activation command for an LTM Candidate Cell (e.g., Candidate Cell TCI States Activation / Deactivation) indicating the LTM Candidate Cell (which is an inter-frequency neighbour cell) and a TCI state which is to be activated in the LTM Candidate Cell, before the UE receives an LTM Cell Switch command for the same LTM Candidate Cell, as a preparation for an inter-frequency LTM Cell Switch for load balancing.

[0252] Embodiment Al 6. A method of Al and all, in response to transmitting the LTM lower layer report, the UE receiving a command for triggering an Early Uplink sync procedure (e.g., Physical Downlink control Channel - PDCCH order), indicating an LTM Candidate Cell (which is an inter-frequency neighbour cell) and a Reference Signal (e.g., SSB identifier) based on which the UE transmits a random access preamble to the LTM Candidate Cell, as a preparation for an inter-frequency LTM Cell Switch for load balancing.

[0253] Embodiment A17. A method of Al and all, in response to transmitting the LTM lower layer report, the UE receiving a command for triggering an Early Uplink sync procedure (e.g., Physical Downlink control Channel - PDCCH order), indicating an LTM Candidate Cell and one or more random access configuration indications associated to a random accessconfiguration of the LTM Candidate Cell, based on which the UE transmits a random access preamble to the LTM Candidate Cell.

[0254] Embodiment Al 8. A method of Al and all, in response to the command for triggering an Early Uplink sync procedure (e.g., Physical Downlink control Channel - PDCCH order), the UE transmits a random access preamble to the LTM Candidate Cell.

[0255] Embodiment Al 8b. A method of Al and all, where, in response to transmitting theLTM lower layer report, the UE receives a command to perform additional measurements on the LTM candidate cell.

[0256] Embodiment A19. A method of Al and A7, wherein the SSB indicated in the LTM lower layer report is configured as QCL source of the TCI state (e.g., TCI State ID) indicated in the LTM Cell Switch Command.

[0257] Embodiment A20. A method of Al and all, wherein the LTM candidate cell on which the measurement is associated is an LTM candidate cell which is an inter-frequency neighbour cell which has a TCI state activated.

[0258] Embodiment A21. A method of Al and all, wherein the measurement performed on the LTM candidate cell which has a TCI activated is performed at least on beam(s) of the LTM Candidate cell associated to the activate TCI state of the LTM candidate cell. The measurements are for at least obtaining T / F synchronization and performing LI measurements.

[0259] Embodiment A21. A method of Al and all, wherein the measurement performed on the LTM candidate cell which has a TCI state activated is performed on an SSB of the LTM Candidate cell configured as QCL source of the activate TCI state of the LTM candidate cell.

[0260] Embodiment A22. A method of Al and all, wherein the measurement performed on the LTM candidate cell depends on the status of a TCI state of the LTM candidate cell, wherein the status may be ‘activated’ or ‘deactivated’.

[0261] Embodiment A23. A method of Al and all, wherein the LTM candidate cell on which the measurement is associated is an LTM candidate cell which has a TCI state deactivated.

[0262] Embodiment A24. A method of Al and all, wherein the measurement performed on the LTM candidate cell which has a TCI state deactivated is performed on a beam of the LTM Candidate cell associated to the deactivate TCI state of the LTM candidate cell and if the UE has additional capability to measure, to measure on the other the RS (than the TCI state deactivated) associated with LTM candidate cell.

[0263] Embodiment A25. A method of Al and all, wherein the measurement performed on the LTM candidate cell which has a TCI state deactivated is performed on an SSB of the LTM Candidate cell configured as QCL source of the deactivate TCI state of the LTM candidate cell.

[0264] Embodiment A26. A method of Al and all, wherein the LTM candidate cell on which the measurement is associated is an LTM candidate cell which has all its configured TCI state(s) deactivated.

[0265] Embodiment A27. A method of Al and all, wherein in response to the LTM lower layer report triggered by the trigger condition in which the LTM candidate cell on which the measurement is associated is an LTM candidate cell which has all its configured TCI state(s) deactivated, the UE receives a lower layer command to activate a TCI state of the LTM candidate cell which has triggered the LTM lower layer report.

[0266] Embodiment A28. A method of Al and all, wherein in response to the LTM lower layer report triggered by the trigger condition in which the LTM candidate cell on which the measurement is associated is an LTM candidate cell which has all its configured TCI state(s) deactivated, the UE receives a lower layer command to trigger an Early UL sync procedure to the LTM candidate cell which has triggered the LTM lower layer report.

[0267] Embodiment A29. A method of Al, wherein the measurement associated to the LTM candidate cell is only performed when there is at least one TCI state of the LTM Candidate cell which is activated.

[0268] Embodiment A30. A method of Al, wherein the UE receives a message including one or more parameters for configuring the triggering condition, and, upon receiving the one or more parameters evaluating the fulfillment of the triggering condition.

[0269] Embodiment A31. A method of A30, wherein the one or more parameters for configuring the triggering condition comprises one or more of: a time to trigger value (e.g., in time units), a trigger quantity (e.g., LI RSRP, LI SINR, LI RSRQ, etc.), one or more reporting quantities (e.g., LI RSRP, LI SINR, LI RSRQ, etc.), a reference signal type (e.g., SSB or CSL RS), an indication of an associated resource configuration (e.g., resource configuration identifier), a value for threshold 1, a value for threshold 2, an event identifier (for identifying the trigger condition).

[0270] Embodiment A32. A method of Al and all, wherein the UE starts evaluating the fulfillment of the trigger condition upon reception of a command associated to a reporting configuration.

[0271] Embodiment A33. A method of Al and all, wherein the command associated to the reporting configuration includes a reporting configuration identifier, and in response to the command the UE evaluates the trigger condition configured in the reporting configuration with a matching reporting configuration identifier.

[0272] Embodiment A34. A method of Al and all, wherein the UE receives a command associated to the reporting configuration includes an indication of one or more frequencies (e.g.,one or more measurement object identifiers), indicating to the UE to monitor the trigger condition of the reporting configuration only for the LTM candidate cells in the indicated one or more frequencies.

[0273] Embodiment A35. A method of Al and all, wherein activating a TCI state of an LTM Candidate cell comprises performing one or more actions associated to a beam and / or RS (e.g., SSB) associated to the TCI state to be activated, such as: i) detecting and / or measuring at least one synchronization signal of the LTM candidate cell, such as an SSB of the LTM candidate cell associated to an SSB index and / or identifier and transmitted in a spatial direction (beam), and / or a CSLRS and / or a TRS and / or a PSS and / or a SSS; ii) performing fine time tracking and acquiring full timing information of the LTM candidate cell. iii) obtaining the time boundaries of time units of a given LTM candidate cell such as time slot, OFDM symbol, subframe, radio frame. iv) synchronizing a clock with the boundaries of time units of a given LTM candidate cell such as time slot, OFDM symbol, subframe, radio frame.

[0274] Embodiment B 1. A method at a network node comprising: configuring a UE to transmit an LTM lower layer report upon fulfillment of a triggering condition, receiving the LTM lower layer report, when the triggering condition is fulfilled, wherein the triggering condition is defined as a measurement associated to an LTM candidate cell becomes better than absolute threshold in response to the received LTM lower layer report, transmitting one or more of:An LTM Cell switch command (e.g., LTM Cell Switch Command)A TCI activation command for an LTM Candidate Cell (e.g., Candidate Cell TCI States Activation / Deactivation)A command for triggering an Early Uplink sync procedure (e.g., PDCCH order for a random access preamble transmission to an LTM Candidate Cell).

[0275] Embodiment B2. A method of Bl and all, wherein the network node configures the triggering condition based on a load balancing function, such as when a load-related measurement on a serving cell and / or a serving frequency is higher than a value.

[0276] Embodiment B2a. The method in Bl and B2, wherein the triggering condition for load balancing are decided by a network node which is different from the network node which receives the lower layer report.

[0277] In one option, a first network node, e.g., a CU, informs a second network node, e.g., DU, about the request to configure triggering conditions for load balancing scenarios. Together with the request, the first network node may also share load balancing statistics

[0278] In one option, a second network node, e.g., a DU, upon receiving a request from a first network node, e.g., CU, to request to configure triggering condition for load balancing, it can decide the right configuration for the event. One way how the second network may decide which configuration for event for load balancing to generate is based on load balancing statistics shared by the first network node.

[0279] Embodiment B3. A method of Bl and all, wherein the LTM candidate cell is an inter-frequency neighbour.

[0280] Embodiment B4. A method of B 1 and all, wherein in response to receiving the LTM lower layer report, the network node transmitting an LTM Cell Switch Command indicating an LTM Candidate Cell (which is an inter-frequency neighbour cell) and a TCI state which is to be activated by the UE in the LTM Candidate Cell which becomes the target cell or the UE receiving a release with redirect command indicating an SSB frequency which is different than the SSB frequency of the PCell.

[0281] Embodiment B4a. A method in Bl and B4, wherein the network node receiving the LTM lower layer report, e.g., a DU, send a request to a second network node CU, before sending the LTM cell switch command to the UE to indicate an LTM candidate cell.

[0282] In one option, the request includes the received LTM lower layer report and is the second network node (e.g., a CU) which decides the LTM candidate cell to be included in the LTM cel switch command. In this case, the second network node indicates the LTM candidate cell to the first network node (a DU, or another CU) and this node include the indicated LTM candidate cell within the LTM cell switch command.

[0283] In one option, the request includes one or more LTM candidate cells which can be included in the LTM cell switch command and the second network node decides which one to include. In this case, the second network node indicates the LTM candidate cell to the first network node (a DU, or another CU) and this node include the indicated LTM candidate cell within the LTM cell switch command.

[0284] In one option, the request is for the second network node (CU) to provide load balancing statistics so that the first network node (DU, or another CU) can decide which LTM candidate cell to be included within the LTM cell switch command. In this case, the second network node indicates the for each on the indicated LTM candidate cells that potentially can be included within the LTM cell switch command.

[0285] In one option, after sending the request to a second network node, the first network node takes the decision on which LTM candidate cell to be included within the LTM cell switch command based on the load balancing information received from the second network node.

[0286] Embodiment B4b. A method of Bl and all, wherein the indicated LTM Candidate Cell in the LTM Cell Switch Command (which is an inter-frequency neighbour cell) has a load measurements with a lower value compared to the load of the PCell and / or a cell in the PCell’s SSB frequency.

[0287] In one option, the load balancing measurements are received by a second network node, e.g., CU.

[0288] Embodiment B5. A method of Bl and all, wherein the LTM Cell Switch Command indicates an LTM Candidate Cell (which is an inter-frequency cell) included in the LTM lower layer report and a TCI state (e.g., TCI State ID) associated to a beam and / or a RS and / or an SSB indicated in the LTM lower layer report.

[0289] Embodiment B6. A method of B 1 and all, in response to receiving the LTM lower layer report, the network node transmitting a TCI activation command for an LTM Candidate Cell (e.g., Candidate Cell TCI States Activation / Deactivation) indicating an LTM Candidate Cell (which is an inter-frequency neighbour cell) and a TCI state which is to be activated by the UE in the LTM Candidate Cell, as a preparation for an inter-frequency LTM Cell Switch for load balancing.

[0290] Embodiment B6a. A method in Bl and B6, wherein the network node receiving the LTM lower layer report, e.g., a DU, send a request to a second network node CU, before sending the TCI activation command for an LTM Candidate Cell to the UE to indicate an LTM candidate cell.

[0291] In one option, the request includes the received LTM lower layer report and is the second network node (e.g., a CU) which decides the LTM candidate cell to be included in the TCI activation command for an LTM Candidate Cell. In this case, the second network node indicates the LTM candidate cell to the first network node (a DU, or another CU) and this node include the indicated LTM candidate cell within the TCI activation command for an LTM Candidate Cell.

[0292] In one option, the request includes one or more LTM candidate cells which can be included in the TCI activation command for an LTM Candidate Cell and the second network node decides which one to include. In this case, the second network node indicates the LTM candidate cell to the first network node (a DU, or another CU) and this node include the indicated LTM candidate cell within the TCI activation command for an LTM Candidate Cell.

[0293] In one option, the request is for the second network node (CU) to provide load balancing statistics so that the first network node (DU, or another CU) can decide which LTM candidate cell to be included within the TCI activation command for an LTM Candidate Cell. In this case, the second network node indicates the for each on the indicated LTM candidate cells that potentially can be included within the TCI activation command for an LTM Candidate Cell.

[0294] In one option, after sending the request to a second network node, the first network node takes the decision on which LTM candidate cell to be included within the TCI activation command for an LTM Candidate Cell based on the load balancing information received from the second network node.

[0295] Embodiment B7. A method of B 1 and all, wherein the network node transmits the TCI activation command for an LTM Candidate Cell (e.g., Candidate Cell TCI States Activation / Deactivation) indicating the LTM Candidate Cell (which is an inter-frequency neighbour cell) and a TCI state which is to be activated by the UE in the LTM Candidate Cell, before the network node transmits an LTM Cell Switch command for an LTM Candidate Cell, as a preparation for an inter-frequency LTM Cell Switch for load balancing.

[0296] Embodiment B8. A method of B 1 and all, wherein the network node transmits the TCI activation command for an LTM Candidate Cell (e.g., Candidate Cell TCI States Activation / Deactivation) indicating the LTM Candidate Cell (which is an inter-frequency neighbour cell) and a TCI state which is to be activated by the UE in the LTM Candidate Cell, before the network node transmits an LTM Cell Switch command for the same LTM Candidate Cell, as a preparation for an inter-frequency LTM Cell Switch for load balancing.

[0297] Embodiment B9. A method of B 1 and all, wherein in response to receiving the LTM lower layer report, the network node transmitting a command for triggering an Early Uplink sync procedure (e.g., Physical Downlink control Channel - PDCCH order), indicating an LTM Candidate Cell (which is an inter-frequency neighbour cell) and a Reference Signal (e.g., SSB identifier) TCI state based on which the UE transmits a random access preamble to the LTM Candidate Cell, as a preparation for an inter-frequency LTM Cell Switch for load balancing.

[0298] Embodiment B9a. A method in Bl and B9, wherein the network node receiving the LTM lower layer report, e.g., a DU, send a request to a second network node CU, before sending a command for triggering an Early Uplink sync procedure to the UE to indicate an LTM candidate cell.

[0299] In one option, the request includes the received LTM lower layer report and is the second network node (e.g., a CU) which decides the LTM candidate cell to be included in a command for triggering an Early Uplink sync procedure. In this case, the second network node indicates the LTM candidate cell to the first network node (a DU, or another CU) and this nodeinclude the indicated LTM candidate cell within a command for triggering an Early Uplink sync procedure.

[0300] In one option, the request includes one or more LTM candidate cells which can be included in a command for triggering an Early Uplink sync procedure and the second network node decides which one to include. In this case, the second network node indicates the LTM candidate cell to the first network node (a DU, or another CU) and this node include the indicated LTM candidate cell within a command for triggering an Early Uplink sync procedure.

[0301] In one option, the request is for the second network node (CU) to provide load balancing statistics so that the first network node (DU, or another CU) can decide which LTM candidate cell to be included within a command for triggering an Early Uplink sync procedure. In this case, the second network node indicates the for each on the indicated LTM candidate cells that potentially can be included within a command for triggering an Early Uplink sync procedure.

[0302] In one option, after sending the request to a second network node, the first network node takes the decision on which LTM candidate cell to be included within a command for triggering an Early Uplink sync procedure based on the load balancing information received from the second network node.

[0303] Embodiment B10. A method of Bl and all, wherein in response to receiving the LTM lower layer report, the network node transmitting a command for triggering an Early Uplink sync procedure (e.g., Physical Downlink control Channel - PDCCH order), indicating an LTM Candidate Cell (which is an inter-frequency neighbour cell) and a Reference Signal (e.g., SSB identifier) TCI state, and receiving a random access preamble in the LTM Candidate Cell.

[0304] Embodiment Bl 1. A method of Bl and all, in response to receiving the LTM lower layer report, transmitting a command for triggering an Early Uplink sync procedure (e.g., Physical Downlink control Channel - PDCCH order), indicating an LTM Candidate Cell and one or more random access configuration indications associated to a random access configuration of the LTM Candidate Cell for the UE to transmit a random access preamble to the LTM Candidate Cell.

[0305] Embodiment B 12. A method of Bl and all, in response to receiving the LTM lower layer report, transmitting a command for triggering an Early Uplink sync procedure (e.g., Physical Downlink control Channel - PDCCH order), indicating an LTM Candidate Cell and one or more random access configuration indications associated to a random access configuration of the LTM Candidate Cell and receiving a random access preamble in the LTM Candidate Cell.

[0306] Embodiment B 13. A method of Bl and all, wherein in response to the received LTM lower layer report including an LTM candidate cell which has all its configured TCI state(s) deactivated, the network node transmits a lower layer command to activate a TCI state of the LTM candidate cell which has triggered the LTM lower layer report.

[0307] Embodiment Bl 5. A method of Bl and all, wherein in response to the received LTM lower layer report including an LTM candidate cell which has all its configured TCI state(s) deactivated, the network node transmits a lower layer command to trigger an Early UL sync procedure to the LTM candidate cell which has triggered the LTM lower layer report.

[0308] Embodiment Bl 6. A method of Bl and all, wherein the network node transmits to the UE a message including one or more parameters for configuring the triggering condition, for the UE to evaluate the fulfillment of the triggering condition.

[0309] Embodiment Bl 7. A method of Bl and all, wherein the one or more parameters for configuring the triggering condition comprises one or more of: a time to trigger value (e.g., in time units), a trigger quantity (e.g., LI RSRP, LI SINR, LI RSRQ, etc.), one or more reporting quantities (e.g., LI RSRP, LI SINR, LI RSRQ, etc.), a reference signal type (e.g., SSB or CSL RS), an indication of an associated resource configuration (e.g., resource configuration identifier), a value for threshold 1, a value for threshold 2, an event identifier (for identifying the trigger condition).

[0310] Embodiment 1. A method of operating a communication device, the method comprising: determining (840) that a triggering condition is met based on a measurement associated with a layer 1 / layer 2-triggered mobility, LTM, candidate cell; and responsive to determining that the triggering condition is met, transmitting (850) a LTM lower layer measurement report.

[0311] Embodiment 2. The method of Embodiment 1, wherein determining that the triggering condition is met comprises: comparing the measurement to a threshold value.

[0312] Embodiment s. The method of Embodiment any of Embodiments 1-2, further comprising: determining (820) the measurement.

[0313] Embodiment 4. The method of Embodiment 3, wherein determining the measurement comprises determining a measurement of a beam of the LTM candidate cell.

[0314] Embodiment 5. The method of Embodiment 4, wherein determining the measurement of the beam of the LTM candidate cell comprises determining at least one of: the beam;a reference signal identifier, ID; and a measurement quantity value.

[0315] Embodiment 6. The method of any of Embodiments 3-5, wherein determining the measurement comprises determining an indication of a best beam of the LTM candidate cell.

[0316] Embodiment 7. The method of any of Embodiments 3-6, wherein determining the first measurement comprises determining a cell level measurement of the LTM candidate cell.

[0317] Embodiment 8. The method of any of Embodiments 3-7, wherein determining the measurement comprises determining a cell quality of the LTM candidate cell.

[0318] Embodiment 9. The method of any of Embodiments 1-8, wherein the LTM candidate cell is an inter-frequency neighbor.

[0319] Embodiment 10. The method of any of Embodiments 1-9, wherein a center frequency of the LTM candidate cell is different from a center frequency of a serving cell, and / or wherein a subcarrier spacing of a synchronization signal block of the LTM candidate cell is different from a subcarrier spacing of a synchronization signal block of the serving cell.

[0320] Embodiment 11. The method of any of Embodiments 1-10, wherein the measurement associated with the LTM candidate cell is a first measurement, wherein transmitting the LTM lower layer report comprises transmitting at least one of: an indication of the first measurement; an indication of a second measurement associated with a serving cell; an indication of the LTM candidate cell associated with the first measurement; and an indication of the serving cell associated with the second measurement.

[0321] Embodiment 12. The method of any of Embodiments 1-11, wherein the TCI state activated within the LTM candidate cell is a second TCI state, the method further comprising: responsive to transmitting the LTM lower layer report, receiving (560) a command indicating an activation of a first TCI state within the LTM candidate cell.

[0322] Embodiment 13. The method of Embodiment 12, wherein the command further indicates a deactivation of the second TCI state within the LTM candidate cell.

[0323] Embodiment 14. The method of any of Embodiments 12-13, wherein receiving the command comprises receiving a LTM cell switching command, wherein the first TCI state is different than the second TCI state.

[0324] Embodiment 15. The method of any of Embodiments 12-13, wherein receiving the command comprises receiving a TCI state activation command or a TCI state deactivation command.

[0325] Embodiment 16. The method of any of Embodiments 12-15, wherein receiving the command comprises receiving a request to trigger an early uplink synchronization procedure.

[0326] Embodiment 17. The method of any of Embodiments 1-16, further comprising: receiving (810) an indication of configuration information from a network node, the configuration information configuring the communication device to transmit the LTM lower layer report in response to the triggering condition being met.

[0327] Embodiment 18. The method of Embodiment 17, wherein receiving the indication of the configuration information comprises receiving a reporting configuration associated to a resource configuration, the resource configuration indicating at least one resource to be measured and used as input to the triggering condition.

[0328] Embodiment 19. A method of operating a network node, the method comprising: transmitting (910) an indication of configuration information to a communication device, the configuration information configuring the communication device to transmit a layer 1 / layer 2 -triggered mobility, LTM, lower layer report in response to fulfillment of a triggering condition, the triggering condition being based on comparing a measurement to a threshold value, the measurement being associated with a LTM candidate cell; and receiving (920) the LTM lower layer measurement report from the communication device.

[0329] Embodiment 20. The method of Embodiment 19, wherein the LTM candidate cell is an inter-frequency neighbor.

[0330] Embodiment 21. The method of any of Embodiments 19-20, further comprising: transmitting (930) a command to the communication device.

[0331] Embodiment 22. The method of Embodiment 21, wherein transmitting the command comprises transmitting at least one of: an LTM Cell switch command; a TCI activation command for an LTM Candidate Cell; and a command for triggering an Early Uplink sync procedure.

[0332] Embodiment 23. The method of any of Embodiments 19-22, further comprising: determining (905) the configuration information based on a load balancing function.

[0333] Embodiment 24. A communication device (QQ200) adapted to perform operations comprising: determining (840) that a triggering condition is met based on a measurement associated with a layer 1 / layer 2-triggered mobility, LTM, candidate cell; and responsive to determining that the triggering condition is met, transmitting (850) a LTM lower layer measurement report.

[0334] Embodiment 25. The communication device of Embodiment 24, the operations further comprising any of the operations of Embodiments 2-18.

[0335] Embodiment 26. A computer program comprising program code to be executed by processing circuitry (QQ202) of a communication device (QQ200), whereby execution of the program code causes the communication device to perform operations comprising: determining (840) that a triggering condition is met based on a measurement associated with a layer 1 / layer 2-triggered mobility, LTM, candidate cell; and responsive to determining that the triggering condition is met, transmitting (850) a LTM lower layer measurement report.

[0336] Embodiment 27. The computer program of Embodiment 26, the operations further comprising any of the operations of Embodiments 2-18.

[0337] Embodiment 28. A computer program product comprising a non-transitory storage medium (QQ210) including program code to be executed by processing circuitry (QQ202) of a communication device (QQ200), whereby execution of the program code causes the communication device to perform operations comprising: determining (840) that a triggering condition is met based on a measurement associated with a layer 1 / layer 2-triggered mobility, LTM, candidate cell; and responsive to determining that the triggering condition is met, transmitting (850) a LTM lower layer measurement report.

[0338] Embodiment 29. The computer program product of Embodiment 28, further comprising any of the operations of Embodiments 2-18.

[0339] Embodiment 30. A network node (QQ300) adapted to perform operations comprising: transmitting (910) an indication of configuration information to a communication device, the configuration information configuring the communication device to transmit a layer 1 / layer 2-triggered mobility, LTM, lower layer report in response to fulfillment of a triggering condition, the triggering condition being based on comparing a measurement to a threshold value, the measurement being associated with a LTM candidate cell; and receiving (920) the LTM lower layer measurement report from the communication device.

[0340] Embodiment 31. The network node of Embodiment 30, the operations further comprising any of the operations of Embodiments 20-23.

[0341] Embodiment 32. A computer program comprising program code to be executed by processing circuitry (QQ302) of a network node (QQ300), whereby execution of the program code causes the network node to perform operations comprising:transmitting (910) an indication of configuration information to a communication device, the configuration information configuring the communication device to transmit a layer 1 / layer 2 -triggered mobility, LTM, lower layer report in response to fulfillment of a triggering condition, the triggering condition being based on comparing a measurement to a threshold value, the measurement being associated with a LTM candidate cell; and receiving (920) the LTM lower layer measurement report from the communication device.

[0342] Embodiment 33. The computer program of Embodiment 32, further comprising any of the operations of Embodiments 20-23.

[0343] Embodiment 34. A computer program product comprising a non-transitory storage medium (QQ304) including program code to be executed by processing circuitry (QQ302) of a network node (QQ300), whereby execution of the program code causes the network node to perform operations comprising: transmitting (910) an indication of configuration information to a communication device, the configuration information configuring the communication device to transmit a layer 1 / layer 2 -triggered mobility, LTM, lower layer report in response to fulfillment of a triggering condition, the triggering condition being based on comparing a measurement to a threshold value, the measurement being associated with a LTM candidate cell; and receiving (920) the LTM lower layer measurement report from the communication device.

[0344] Embodiment 35. The computer program product of Embodiment 34, the operations further comprising any of the operations of Embodiments 20-23.

[0345] FIG. 12 shows an example of a communication system 1200 in accordance with some embodiments.

[0346] In the example, the communication system 1200 includes a telecommunication network 1202 that includes an access network 1204, such as a radio access network (RAN), and a core network 1206, which includes one or more core network nodes 1208. The access network 1204 includes one or more access network nodes, such as network nodes 1210a and 1210b (one or more of which may be generally referred to as network nodes 1210), or any other similar 3rdGeneration Partnership Project (3 GPP) access nodes or non-3GPP access points. Moreover, as will be appreciated by those of skill in the art, a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor. Thus, it will be understood that network nodes include disaggregated implementations or portions thereof. For example, in some embodiments, the telecommunication network 1202 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a node in the telecommunication network 1202 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operatealone or together with other nodes to implement one or more functionalities of any node in the telecommunication network 1202, including one or more network nodes 1210 and / or core network nodes 1208.

[0347] Examples of an ORAN network node include an open radio unit (O-RU), an open distributed unit (O-DU), an open central unit (O-CU), including an O-CU control plane (O-CU- CP) or an O-CU user plane (O-CU-UP), a RAN intelligent controller (near-real time or non-real time) hosting software or software plug-ins, such as a near-real time control application (e.g., xApp) or a non-real time control application (e.g., rApp), or any combination thereof (the adjective “open” designating support of an ORAN specification). The network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an Al, Fl, Wl, El, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN access node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an 0-2 interface defined by the 0-RAN Alliance or comparable technologies. The network nodes 1210 facilitate direct or indirect connection of user equipment (UE), such as by connecting UEs 1212a, 1212b, 1212c, and 1212d (one or more of which may be generally referred to as UEs 1212) to the core network 1206 over one or more wireless connections.

[0348] Example wireless communications over a wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 1200 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that may facilitate or participate in the communication of data and / or signals whether via wired or wireless connections. The communication system 1200 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0349] The UEs 1212 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with the network nodes 1210 and other communication devices. Similarly, the network nodes 1210 are arranged, capable, configured, and / or operable to communicate directly or indirectly with the UEs 1212 and / or with other network nodes or equipment in the telecommunication network 1202 toenable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in the telecommunication network 1202.

[0350] In the depicted example, the core network 1206 connects the network nodes 1210 to one or more host computing systems, such as host 1216. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 1206 includes one more core network nodes (e.g., core network node 1208) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 1208. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0351] The host 1216 may be under the ownership or control of a service provider other than an operator or provider of the access network 1204 and / or the telecommunication network 1202. The host 1216 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio / video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0352] As a whole, the communication system 1200 of FIG. 12 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and / or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and / or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.

[0353] In some examples, the telecommunication network 1202 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunications network 1202 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 1202. For example, the telecommunications network 1202 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and / or Massive Machine Type Communication (mMTC) / Massive loT services to yet further UEs.

[0354] In some examples, the UEs 1212 are configured to transmit and / or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 1204 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 1204. Additionally, a UE may be configured for operating in single- or multi -RAT or multi-standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi -radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

[0355] In the example, the hub 1214 communicates with the access network 1204 to facilitate indirect communication between one or more UEs (e.g., UE 1212c and / or 1212d) and network nodes (e.g., network node 1210b). In some examples, the hub 1214 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 1214 may be a broadband router enabling access to the core network 1206 for the UEs. As another example, the hub 1214 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 1210, or by executable code, script, process, or other instructions in the hub 1214. As another example, the hub 1214 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 1214 may be a content source. For example, for a UE that is a VR device, display, loudspeaker, or other media delivery device, the hub 1214 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 1214 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub 1214 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.

[0356] The hub 1214 may have a constant / persistent or intermittent connection to the network node 1210b. The hub 1214 may also allow for a different communication scheme and / or schedule between the hub 1214 and UEs (e.g., UE 1212c and / or 1212d), and between the hub 1214 and thecore network 1206. In other examples, the hub 1214 is connected to the core network 1206 and / or one or more UEs via a wired connection. Moreover, the hub 1214 may be configured to connect to an M2M service provider over the access network 1204 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 1210 while still connected via the hub 1214 via a wired or wireless connection. In some embodiments, the hub 1214 may be a dedicated hub - that is, a hub whose primary function is to route communications to / from the UEs from / to the network node 1210b. In other embodiments, the hub 1214 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 1210b, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0357] FIG. 13 shows a UE 1300 in accordance with some embodiments. The UE 1300 presents additional details of some embodiments of the UE 1212 of Figure 1. As used herein, a UE refers to a device capable, configured, arranged and / or operable to communicate wirelessly with network nodes and / or other UEs. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, gaming console or device, music storage / playback device, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), an Augmented Reality (AR) or Virtual Reality (VR) device, wireless customer-premise equipment (CPE), vehicle, vehicle-mounted or vehicle embedded / integrated wireless device, etc. Other examples include any UE identified by the 3rd Generation Partnership Project (3GPP), including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0358] A UE may support device-to-device (D2D) communication, for example by implementing a 3 GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle-to- everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0359] The UE 1300 includes processing circuitry 1302 that is operatively coupled via a bus 1304 to an input / output interface 1306, a power source 1308, a memory 1310, a communicationinterface 1312, and / or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in FIG. 13. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0360] The processing circuitry 1302 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in the memory 1310. The processing circuitry 1302 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general-purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 1302 may include multiple central processing units (CPUs).

[0361] In the example, the input / output interface 1306 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and / or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into the UE 1300. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0362] In some embodiments, the power source 1308 is structured as abattery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. The power source 1308 may further include power circuitry for delivering power from the power source 1308 itself, and / or an external power source, to the various parts of the UE 1300 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of the power source 1308. Power circuitry may perform any formatting, converting, or other modification to the power from thepower source 1308 to make the power suitable for the respective components of the UE 1300 to which power is supplied.

[0363] The memory 1310 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 1310 includes one or more application programs 1314, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 1316. The memory 1310 may store, for use by the UE 1300, any of a variety of various operating systems or combinations of operating systems.

[0364] The memory 1310 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and / or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ The memory 1310 may allow the UE 1300 to access instructions, application programs and the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in the memory 1310, which may be or comprise a device-readable storage medium.

[0365] The processing circuitry 1302 may be configured to communicate with an access network or other network using the communication interface 1312. The communication interface 1312 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 1322. The communication interface 1312 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 1318 and / or a receiver 1320 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 1318 and receiver 1320 may be coupled to one or more antennas (e.g., antenna 1322) and may share circuit components, software or firmware, or alternatively be implemented separately.

[0366] In the illustrated embodiment, communication functions of the communication interface 1312 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short- range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented in according to one or more communication protocols and / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol / internet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0367] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 1312, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

[0368] As another example, a UE comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

[0369] A UE, when in the form of an Internet of Things (loT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non-limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door / window sensor, a flood / moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item-tracking device, a sensor for monitoring a plant or animal, anindustrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an loT device comprises circuitry and / or software in dependence of the intended application of the loT device in addition to other components as described in relation to the UE 1300 shown in FIG. 13.

[0370] As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and / or measurements, and transmits the results of such monitoring and / or measurements to another UE and / or a network node. The UE may in this case be an M2M device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation.

[0371] In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g., by controlling an actuator) to increase or decrease the drone’s speed. The first and / or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

[0372] FIG. 14 shows a network node 1400 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged and / or operable to communicate directly or indirectly with a UE and / or with other network nodes or equipment, in a telecommunication network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs, evolved Node Bs (eNBs) and NR NodeBs (gNBs)), 0-RAN nodes or components of an 0-RAN node (e.g., 0-RU, 0-DU, O-CU).

[0373] Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units, distributed units (e.g., in an 0-RAN access node) and / or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio unitsmay or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

[0374] Other examples of network nodes include multiple transmission point (multi-TRP) 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell / multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and / or Minimization of Drive Tests (MDTs).

[0375] The network node 1400 includes a processing circuitry 1402, a memory 1404, a communication interface 1406, and a power source 1408. The network node 1400 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 1400 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 1400 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 1404 for different RATs) and some components may be reused (e.g., a same antenna 1410 may be shared by different RATs). The network node 1400 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 1400, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 1400.

[0376] The processing circuitry 1402 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and / or encoded logic operable to provide, either alone or in conjunction with other network node 1400 components, such as the memory 1404, to provide network node 1400 functionality.

[0377] In some embodiments, the processing circuitry 1402 includes a system on a chip (SOC). In some embodiments, the processing circuitry 1402 includes one or more of radio frequency (RF) transceiver circuitry 1412 and baseband processing circuitry 1414. In someembodiments, the radio frequency (RF) transceiver circuitry 1412 and the baseband processing circuitry 1414 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 1412 and baseband processing circuitry 1414 may be on the same chip or set of chips, boards, or units.

[0378] The memory 1404 may comprise any form of volatile or non-volatile computer- readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device-readable and / or computer-executable memory devices that store information, data, and / or instructions that may be used by the processing circuitry 1402. The memory 1404 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions capable of being executed by the processing circuitry 1402 and utilized by the network node 1400. The memory 1404 may be used to store any calculations made by the processing circuitry 1402 and / or any data received via the communication interface 1406. In some embodiments, the processing circuitry 1402 and memory 1404 is integrated.

[0379] The communication interface 1406 is used in wired or wireless communication of signaling and / or data between a network node, access network, and / or UE. As illustrated, the communication interface 1406 comprises port(s) / terminal(s) 1416 to send and receive data, for example to and from a network over a wired connection. The communication interface 1406 also includes radio front-end circuitry 1418 that may be coupled to, or in certain embodiments a part of, the antenna 1410. Radio front-end circuitry 1418 comprises filters 1420 and amplifiers 1422. The radio front-end circuitry 1418 may be connected to an antenna 1410 and processing circuitry 1402. The radio front-end circuitry may be configured to condition signals communicated between antenna 1410 and processing circuitry 1402. The radio front-end circuitry 1418 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio frontend circuitry 1418 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1420 and / or amplifiers 1422. The radio signal may then be transmitted via the antenna 1410. Similarly, when receiving data, the antenna 1410 may collect radio signals which are then converted into digital data by the radio front-end circuitry 1418. The digital data may be passed to the processing circuitry 1402. In other embodiments, the communication interface may comprise different components and / or different combinations of components.

[0380] In certain alternative embodiments, the network node 1400 does not include separate radio front-end circuitry 1418, instead, the processing circuitry 1402 includes radio front-end circuitry and is connected to the antenna 1410. Similarly, in some embodiments, all or some of the RF transceiver circuitry 1412 is part of the communication interface 1406. In still other embodiments, the communication interface 1406 includes one or more ports or terminals 1416, the radio front-end circuitry 1418, and the RF transceiver circuitry 1412, as part of a radio unit (not shown), and the communication interface 1406 communicates with the baseband processing circuitry 1414, which is part of a digital unit (not shown).

[0381] The antenna 1410 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 1410 may be coupled to the radio front-end circuitry 1418 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 1410 is separate from the network node 1400 and connectable to the network node 1400 through an interface or port.

[0382] The antenna 1410, communication interface 1406, and / or the processing circuitry 1402 may be configured to perform any receiving operations and / or certain obtaining operations described herein as being performed by the network node. Any information, data and / or signals may be received from a UE, another network node and / or any other network equipment. Similarly, the antenna 1410, the communication interface 1406, and / or the processing circuitry 1402 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and / or signals may be transmitted to a UE, another network node and / or any other network equipment.

[0383] The power source 1408 provides power to the various components of network node 1400 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 1408 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 1400 with power for performing the functionality described herein. For example, the network node 1400 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 1408. As a further example, the power source 1408 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

[0384] Embodiments of the network node 1400 may include additional components beyond those shown in FIG. 14 for providing certain aspects of the network node’ s functionality, including any of the functionality described herein and / or any functionality necessary to support the subjectmatter described herein. For example, the network node 1400 may include user interface equipment to allow input of information into the network node 1400 and to allow output of information from the network node 1400. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 1400. In some embodiments providing a core network node, such as core network node 108 of FIG. 12, some components, such as the radio front-end circuitry 1418 and the RF transceiver circuitry 1412 may be omitted.

[0385] FIG. 15 is a block diagram illustrating a virtualization environment 1500 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 1500 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized. In some embodiments, the virtualization environment 1500 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an O-2 interface. Virtualization may facilitate distributed implementations of a network node, UE, core network node, or host.

[0386] Applications 1502 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment Q400 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein.

[0387] Hardware 1504 includes processing circuitry, memory that stores software and / or instructions executable by hardware processing circuitry, and / or other hardware devices as described herein, such as a network interface, input / output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 1506 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 1508a and 1508b (one or more of which may be generally referred to as VMs 1508), and / or perform any of the functions, features and / or benefits described in relation with some embodiments described herein.The virtualization layer 1506 may present a virtual operating platform that appears like networking hardware to the VMs 1508.

[0388] The VMs 1508 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 1506. Different embodiments of the instance of a virtual appliance 1502 may be implemented on one or more of VMs 1508, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

[0389] In the context of NFV, a VM 1508 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of the VMs 1508, and that part of hardware 1504 that executes that VM, be it hardware dedicated to that VM and / or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 1508 on top of the hardware 1504 and corresponds to the application 1502.

[0390] Hardware 1504 may be implemented in a standalone network node with generic or specific components. Hardware 1504 may implement some functions via virtualization. Alternatively, hardware 1504 may be part of a larger cluster of hardware (e.g., such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration 1510, which, among others, oversees lifecycle management of applications 1502. In some embodiments, hardware 1504 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 1512 which may alternatively be used for communication between hardware nodes and radio units.

[0391] Although the computing devices described herein (e.g., UEs, network nodes) may include the illustrated combination of hardware components, other embodiments may comprise computing devices with different combinations of components. It is to be understood that these computing devices may comprise any suitable combination of hardware and / or software needed to perform the tasks, features, functions and methods disclosed herein. Determining, calculating, obtaining or similar operations described herein may be performed by processing circuitry, whichmay process information by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and / or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination. Moreover, while components are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, computing devices may comprise multiple different physical components that make up a single illustrated component, and functionality may be partitioned between separate components. For example, a communication interface may be configured to include any of the components described herein, and / or the functionality of the components may be partitioned between the processing circuitry and the communication interface. In another example, non-computationally intensive functions of any of such components may be implemented in software or firmware and computationally intensive functions may be implemented in hardware.

[0392] In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored on in memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer- readable storage medium. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry without executing instructions stored on a separate or discrete device-readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a non-transitory computer-readable storage medium or not, the processing circuitry can be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processing circuitry alone or to other components of the computing device, but are enjoyed by the computing device as a whole, and / or by end users and a wireless network generally.

Claims

CLAIMS1. A method of operating a communication device, the method comprising: determining (840) that a triggering condition is met based on a measurement associated with a layer 1 / layer 2-triggered mobility, LTM, candidate cell; and responsive to determining that the triggering condition is met, transmitting (850) a LTM lower layer measurement report.

2. The method of Claim 1, wherein the measurement associated with the LTM candidate cell is a first measurement, wherein transmitting the LTM lower layer report comprises transmitting at least one of: an indication of the first measurement; an indication of a second measurement associated with a serving cell; an indication of the LTM candidate cell associated with the first measurement; and an indication of the serving cell associated with the second measurement.

3. The method of any of Claims 1-2, wherein determining that the triggering condition is met comprises: comparing the measurement to a threshold value.

4. The method of any of Claims 1-3, further comprising: determining (820) the measurement.

5. The method of Claim 4, wherein determining the measurement comprises determining a measurement of a beam of the LTM candidate cell.

6. The method of Claim 5, wherein determining the measurement of the beam of the LTM candidate cell comprises determining at least one of: the beam; a reference signal identifier, ID; and a measurement quantity value.

7. The method of any of Claims 4-6, wherein determining the measurement comprises determining an indication of a best beam of the LTM candidate cell.

8. The method of any of Claims 4-7, wherein determining the measurement comprises determining a cell level measurement of the LTM candidate cell.

9. The method of any of Claims 4-8, wherein determining the measurement comprises determining a cell quality of the LTM candidate cell.

10. The method of any of Claims 1-9, wherein the LTM candidate cell is an inter-frequency neighbor.

11. The method of any of Claims 1-10, wherein a center frequency of the LTM candidate cell is different from a center frequency of a serving cell, and / or wherein a subcarrier spacing of a synchronization signal block of the LTM candidate cell is different from a subcarrier spacing of a synchronization signal block of the serving cell.

12. The method of any of Claims 1-11, wherein the TCI state activated within the LTM candidate cell is a second TCI state, the method further comprising: responsive to transmitting the LTM lower layer report, receiving (860) a command indicating an activation of a first TCI state within the LTM candidate cell.

13. The method of Claim 12, wherein the command further indicates a deactivation of the second TCI state within the LTM candidate cell.

14. The method of any of Claims 12-13, wherein receiving the command comprises receiving a LTM cell switch command, and wherein the first TCI state is different than the second TCI state.

15. The method of any of Claims 12-13, wherein receiving the command comprises receiving a TCI state activation command or a TCI state deactivation command.

16. The method of any of Claims 1-11, wherein receiving the command comprises receiving a request to trigger an early uplink synchronization procedure.

17. The method of any of Claims 1-16, further comprising: receiving (810) an indication of configuration information from a network node, theconfiguration information configuring the communication device to transmit the LTM lower layer report in response to the triggering condition being met.

18. The method of Claim 17, wherein receiving the indication of the configuration information comprises receiving a reporting configuration associated to a resource configuration, the resource configuration indicating at least one resource to be measured and used as input to the triggering condition.

19. A method of operating a network node, the method comprising: transmitting (910) an indication of configuration information to a communication device, the configuration information configuring the communication device to transmit a layer 1 / layer 2 -triggered mobility, LTM, lower layer report in response to fulfillment of a triggering condition, the triggering condition being based on comparing a measurement to a threshold value, the measurement being associated with a LTM candidate cell; and receiving (920) the LTM lower layer measurement report from the communication device.

20. The method of Claim 19, wherein the LTM candidate cell is an inter-frequency neighbor.

21. The method of any of Claims 19-20, further comprising: transmitting (930) a command to the communication device.

22. The method of Claim 21, wherein transmitting the command comprises transmitting at least one of: an LTM Cell switch command; a TCI activation command for an LTM Candidate Cell; and a command for triggering an Early Uplink sync procedure.

23. The method of any of Claims 19-22, further comprising: determining (905) the configuration information based on a load balancing function.

24. A communication device (1300) adapted to perform operations comprising: determining (840) that a triggering condition is met based on a measurement associated with a layer 1 / layer 2-triggered mobility, LTM, candidate cell; and responsive to determining that the triggering condition is met, transmitting (850) a LTM lower layer measurement report.

25. The communication device of Claim 24, the operations further comprising any of the operations of Claims 2-18.

26. A computer program comprising program code to be executed by processing circuitry (1302) of a communication device (1300), whereby execution of the program code causes the communication device to perform operations comprising: determining (840) that a triggering condition is met based on a measurement associated with a layer 1 / layer 2-triggered mobility, LTM, candidate cell; and responsive to determining that the triggering condition is met, transmitting (850) a LTM lower layer measurement report.

27. The computer program of Claim 26, the operations further comprising any of the operations of Claims 2-18.

28. A computer program product comprising a non-transitory storage medium (1310) including program code to be executed by processing circuitry (1302) of a communication device (1300), whereby execution of the program code causes the communication device to perform operations comprising: determining (840) that a triggering condition is met based on a measurement associated with a layer 1 / layer 2-triggered mobility, LTM, candidate cell; and responsive to determining that the triggering condition is met, transmitting (850) a LTM lower layer measurement report.

29. The computer program product of Claim 28, further comprising any of the operations of Claims 2-18.

30. A network node (1400) adapted to perform operations comprising: transmitting (910) an indication of configuration information to a communication device, the configuration information configuring the communication device to transmit a layer 1 / layer 2-triggered mobility, LTM, lower layer report in response to fulfillment of a triggering condition, the triggering condition being based on comparing a measurement to a threshold value, the measurement being associated with a LTM candidate cell; and receiving (920) the LTM lower layer measurement report from the communication device.

31. The network node of Claim 30, the operations further comprising any of the operations of Claims 20-23.

32. A computer program comprising program code to be executed by processing circuitry (1402) of a network node (1400), whereby execution of the program code causes the network node to perform operations comprising: transmitting (910) an indication of configuration information to a communication device, the configuration information configuring the communication device to transmit a layer 1 / layer 2 -triggered mobility, LTM, lower layer report in response to fulfillment of a triggering condition, the triggering condition being based on comparing a measurement to a threshold value, the measurement being associated with a LTM candidate cell; and receiving (920) the LTM lower layer measurement report from the communication device.

33. The computer program of Claim 32, further comprising any of the operations of Claims 20-23.

34. A computer program product comprising a non-transitory storage medium (1404) including program code to be executed by processing circuitry (1402) of a network node (1400), whereby execution of the program code causes the network node to perform operations comprising: transmitting (910) an indication of configuration information to a communication device, the configuration information configuring the communication device to transmit a layer 1 / layer 2 -triggered mobility, LTM, lower layer report in response to fulfillment of a triggering condition, the triggering condition being based on comparing a measurement to a threshold value, the measurement being associated with a LTM candidate cell; and receiving (920) the LTM lower layer measurement report from the communication device.

35. The computer program product of Claim 34, the operations further comprising any of the operations of Claims 20-23.

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