UE and NB for early CSI acquisition and methods thereof

Abstract

The present disclosure provides a method performed by a UE for early CSI acquisition in LTM procedures. The method includes receiving a configuration for early CSI acquisition, the configuration including one or more LTM candidate cells, receiving a command for LTM cell switch to a target cell among the one or more LTM candidate cells, and starting to perform CSI- RS measurements CRI / CQI / PMI and / or RI upon receiving the command. The method enables reduced link adaptation time in the target cell by initiating CSI measurements immediately upon receiving the LTM cell switch command.

Description

P113067W001 1UE AND NB FOR EARLY CSI ACQUISITION AND METHODS THEREOFThis application claims the benefit of provisional patent application serial number US63 / 759782, filed 2 / 18 / 2025, the disclosure of which is hereby incorporated herein by reference in its entirety.FIELD OF INVENTION

[0001] The present disclosure relates to wireless communication systems, and more particularly to methods and apparatus for user equipment channel state information reference signal measurement operations on LTM candidate cells.BACKGROUND

[0002] Wireless communication systems have evolved to support increasingly sophisticated mobility procedures to maintain connectivity as user equipment (UE) moves between different cells or coverage areas. Traditional mobility procedures, such as handover operations, typically rely on Radio Resource Control (RRC) layer signaling and Layer 3 measurements to coordinate the transition of a UE from a source cell to a target cell. These procedures involve measurement reporting, handover preparation, and execution phases that can introduce latency and interruption during cell transitions.

[0003] Layer- l / Layer-2 triggered mobility (LTM) has been introduced as an enhancement to reduce handover latency and interruption time compared to conventional Layer 3 based mobility procedures. In LTM, a base station receives Layer 1 measurement reports from a UE and can initiate a cell switch using lower layer signaling, such as a Medium Access Control (MAC) Control Element (CE), rather than requiring RRC reconfiguration messages. The LTM procedure involves pre-configuring the UE with candidate cell configurations through RRC signaling, after which the network can trigger rapid cell switches using MAC CE commands that reference these pre-stored configurations.

[0004] To further optimize LTM performance, pre-synchronization techniques have been developed where UE can establish downlink synchronization (also referred to as DL pre-sync) with candidate cells before receiving the actual cell switch command. This pre-synchronization is achieved through early activation of Transmission Configuration Indicator (TCI) states for LTM candidate cells, allowing the UE to be ready for faster cell switching when triggered by the network. The pre-activation of a candidate TCI state is done before the LTM cell switch procedure, i.e., before any of those cells become the serving cell.P113067W001 2

[0005] Channel State Information (CSI) acquisition represents another aspect of wireless communication systems where UE measures and reports channel conditions to enable link adaptation and optimal transmission parameters. CSI measurements are typically based on Channel State Information Reference Signals (CSI-RS) and can include various metrics such as Channel Rank Indicator (CRI), Channel Quality Indicator (CQI), Precoding Matrix Indicator (PMI), and Rank Indicator (RI). The timing of CSI measurements and reporting is governed by reference resource definitions and UE processing delay requirements specified in technical standards.

[0006] UE devices have finite processing capabilities for simultaneous CSI calculations, characterized by a limited number of CSI processing units (CPUs), and can only measure a limited number of active CSI-RS resources simultaneously. These capacity limitations are communicated to the network through UE capability reporting and influence how CSI measurements are scheduled and prioritized.

[0007] However, existing LTM implementations face challenges when attempting to incorporate early CSI acquisition for candidate cells. After an LTM cell switch occurs, the new serving cell must configure the UE with CSI reports and wait for UE CSI feedback before effective link adaptation can be performed. During this period, the UE experiences reduced uplink and downlink throughput compared to the performance achievable after CSI information becomes available to the target cell.

[0008] The integration of CSI measurements for multiple LTM candidate cells presents resource management challenges for UE devices. When configured with numerous candidate cells for LTM operations, the total number of required CSI-RS measurements can exceed UE processing capabilities for active CSI-RS resources and available CSI processing units. Current specifications treat all configured periodic CSI-RS resources as active, which becomes problematic in LTM scenarios where many candidate cells may be configured simultaneously.

[0009] The lack of clear guidelines for managing CSI-RS measurements across multiple LTM candidate cells creates uncertainty in UE behavior and can lead to suboptimal resource utilization. Without proper prioritization mechanisms and capability management, UE devices may be unable to perform the necessary measurements to support effective early CSI acquisition for LTM procedures.

[0010] It has been appreciated that a method is needed that overcomes one or more of these problems.P113067W001 3SUMMARY

[0011] This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description.

[0012] In a first aspect, a method performed by a user equipment (UE) is provided. The method comprises receiving a configuration for early CSI acquisition, the configuration including one or more LTM candidate cells, receiving a command for LTM cell switch to a target cell, wherein the target cell is one of the one or more LTM candidate cells, and starting to perform CSI reference signal, CSI-RS, measurements upon receiving the command, the CSI-RS measurements including at least one of CRI, CQI, PMI, and RI.

[0013] This approach enables the UE to begin CSI measurements immediately upon receiving the LTM cell switch command, reducing the time required for link adaptation in the target cell and improving throughput performance directly after cell switch execution.

[0014] The method may further comprise transmitting a layer-1 reference signal received power, Ll-RSRP, measurement result to a serving cell of the UE. Providing Ll-RSRP measurements to the serving cell enables the network to make informed decisions about LTM cell switch timing and target cell selection based on current signal conditions.

[0015] The configuration for early CSI acquisition may comprise an indication of periodic or semi-periodic CSI-RS resources for the one or more LTM candidate cells to be measured. Configuring specific CSI-RS resources for LTM candidate cells allows the network to control which measurements the UE performs and ensures efficient use of UE processing capabilities.

[0016] The method may further comprise when CSI-RS resources indicated by the early CSI configuration exceed a predetermined limit, applying prioritization for the measurement. Applying prioritization when resource limits are exceeded ensures that the UE can continue to operate within its processing capabilities while focusing on the most relevant measurements for LTM operations. Further, the prioritization may be applied according to certain prioritization criteria.

[0017] The method may further include transmitting to the serving cell information indicating the UE’s capability to support for the early CSI acquisition. Communicating UE capabilities to the serving cell enables the network to configure appropriate CSI measurement tasks that match the UE's processing limitations and avoid overloading the device. The serving cell can determine the configuration of the early CSI acquisition based on the reported capability.

[0018] The UE capability may comprise information regarding a maximum number of CSI-RS resources and / or ports that the UE supports simultaneous measurement across all configured LTM candidate cells or per LTM Candidate cell. Further, it may comprise information regardingP113067W001 4a number of CSI processing units that the UE supports for the CSI-RS measurements including at least one of CRI, CQI, PMI, and RI.

[0019] In a second aspect, a method performed by a network node is provided. The method comprises transmitting a configuration for early CSI acquisition to a served UE, the configuration including one or more layer- l / layer-2 triggered mobility, LTM, candidate cells. And the network node transmits a command for LTM cell switch to a target cell to the UE, which belongs to the one or more LTM candidate cells. Then the network node receives CSI measurement results including at least one of.

[0020] This network-side approach enables coordinated early CSI acquisition for LTM procedures, allowing the network to obtain channel state information for target cells and perform effective link adaptation immediately after cell switch completion.

[0021] The method may further comprise receiving a layer-1 reference signal received power, Ll-RSRP, measurement result from the UE, and deciding the LTM cell switch for the UE.

[0022] In a third aspect, a user equipment (UE) is provided. The UE includes memory configured to store instructions to be executed by its processing circuitry, and cause the UE to perform those embodiments of the first aspect of this disclosure.

[0023] In a fourth aspect, a network node is provided. The network node includes memory configured to store instructions to be executed by its processing circuitry, and cause the network node to perform those embodiments of the first aspect of this disclosure.BRIEF DESCRIPTION OF FIGURESEmbodiments of the invention will be described, by way of example, with reference to the following drawings, in which:

[0024] FIG. 1 illustrates a sequence diagram of a current overall Lower Layer Triggered Mobility procedure.

[0025] FIG. 2 depicts a timeline diagram showing CSI reference resource timing with periodic CSI-RS transmissions, according to current CSI-RS measurement scheme.

[0026] FIG. 3 illustrates a timeline diagram showing CSI reference resource timing with aperiodic CSI report trigger (DCI), according to the current CSI-RS measurement scheme.

[0027] FIG. 4 illustrates operations of a UE and a network node according to some embodiments of the present disclosure.

[0028] FIG. 5 illustrates operations of a UE and a network node according to some embodiments of the present disclosure.P113067W001 5

[0029] FIG. 6 illustrates operations of a UE, a source and a target network node according to some embodiments of the present disclosure.

[0030] FIG. 7 shows an example of a communication system including UEs and network nodes implementing the embodiments of the present disclosure.

[0031] FIG. 8 shows a functional structure of a wireless device being configured to operate in a communication system shown in FIG. 7 and to implement the embodiments of the present disclosure.

[0032] FIG. 9 shows a functional structure of a network node being configured to operate in a communication system shown in FIG. 7 and to implement the embodiments of the present disclosure.DETAILED DESCRIPTION

[0033] The embodiments set forth below represent information to enable those skilled in the art to practice the embodiments and illustrate the best mode of practicing the embodiments. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the disclosure and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure.

[0034] 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.

[0035] The overall procedure for LTM is shown in Figure 1 as follows.

[0036] Step 1 : The UE sends a MeasurementReport message to the gNB. The gNB decides to configure LTM and initiates LTM preparation.

[0037] Step 2: The gNB transmits an RRCReconfiguration message to the UE including the LTM candidate configurations.

[0038] Step 3: The UE stores the LTM candidate configurations and transmits an RRCReconfigurationComplete message to the gNB.

[0039] Step 4a: The UE performs DL synchronization with the candidate cell(s) before receiving the cell switch command. This is triggered upon reception by the UE of a “Candidate Cell TCI States Activation / Deactivation MAC CE” for LTM candidate cell(s) configured in CandidateTCI-State and CandidateTCI-UL-State. Upon reception, in the UE’s MAC entity, the UE’s MAC entity receives a Candidate Cell TCI States Activation / Deactivation MAC CE on aP113067W001 6Serving Cell, and the UE indicate to lower layers the information regarding the Candidate Cell TCI States Activation / Deactivation MAC CE.

[0040] Step 4b: The UE may also perform UL pre-synchronization with the LTM candidate cell(s) if it receives the Physical Downlink Control Channel (PDCCH) order for early timing advance (TA) acquisition for those candidate cells.

[0041] Step 5: 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 (step 2) is applicable.

[0042] Step 6: 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.

[0043] Step 7: The UE performs the random-access procedure towards the target cell, if UE does not have valid TA of the target cell. Otherwise, if the UE receives a valid TA value in LTM cell switch command using early TA acquisition method in step 4b, the UE is not required to perform random-access.

[0044] Step 8: The UE completes the LTM cell switch procedure by sending RRCReconfigurationComplete message to target cell. If the UE has performed a RA procedure in step 7, the UE considers that LTM cell switch execution is successfully completed when the random-access procedure is successfully completed. For Random Access Channel (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.

[0045] In 3GPP Rel-18 where LTM was introduced, during the period after cell switch that the new serving cell has to configure the UE with CSI reports and await UE CSI reports for link adaptation, UE will have reduced uplink (UL) / downlink (DL) throughput compared to after CSI has been reported. This reduced performance directly after cell switch is addressed by a work item in Release 18. The justification mentions that it "can be expected to enable greater throughput on the target cell directly after cell switch”.

[0046] Relevant agreements includes:RAN 1 # 118 -bis AgreementThe following alternatives are further studied:• Alt-1: CSI-RS measurement and CSI reporting operations are performed before reception of LTM Cell Switch Command (CSC) MAC CE.o The report is sent to the serving cell and transferred to the candidate / target cell(s)P113067W001 7Alt-2: CSI-RS measurement can start before reception of LTM CSC MAC CE and CSI reporting operation is performed after reception of LTM CSC MAC CE.o The report is sent directly to target cell• Alt-3 : CSI-RS measurement and CSI reporting operations are performed after reception of LTM CSC MAC CE.o The report is sent directly to target cell

[0047] There’re some further aspects regarding early CSI-acquisition for LTM candidate cells, including• Measurement trigger:o LTM Cell Switch Command MAC CE can be an implicit trigger.o LTM TCI State Activation MAC CE can be an implicit trigger.o PDCCH order toward an LTM Candidate cell can be an implicit trigger. o Explicit trigger.• Report trigger:o Does the serving cell or the target cell trigger the measurement report? • Type of CSI-RS resource:o Whether it is a periodic / semi-persistent or aperiodic CSI-RS.o It will be a multiport CSI RS, how many ports?• Type of CSI:o What type of CSI is reported, e.g. CSI Resource Indicator (CRI) / Channel Quality Indicator (CQI) / Precoding Matrix Indicator (PMI) / Rank Indicator (RI) ?• Delay until the CSI is available in the target cell• UE capacity to compute CSI for one or more LTM candidates

[0048] In the time domain, the CSI reference resource for a CSI reporting in uplink slot n’ is defined by a single downlink slot prior to n’. The time-offset from the reference-resource to slot n’ is a function of the UE delay requirement Z’, referring to Section 5 of 3GPP TS 38.214 V18.4.0, which is for the delay from the late time of receiving RS for channel measurement used for CSI computation or interference measurement used for CSI computation to the time for sending the CSI report. Another type of delay requirement, Z, is for the delay from the time of the Downlink Control Information (DCI) scheduling the report to the time for sending the report.

[0049] Reference signals received no later than the reference resource can be used for computing the CSI which is reported. As an example, consider Figure 2 where a periodic reference signal is configured with the different transmission occasions of the periodic reference signal denoted by Reference Signal (RS) #1, RS#2, and RS#3. A CSI report is to be reported at slot n’,P113067W001 8and the time-domain location of the corresponding reference resource follows the specification 3GPP Technical Specification (TS) 38.214 Sec 5.2.2.5. The transmission occasion RS#1 occurs before the reference resource; hence it is used by the UE to compute the CSI of the report.

[0050] On the other hand, reference signals received after the reference resource may not be used for the CSI report. Hence, the transmission occasion RS#2 may not be used for the CSI report. The rationale for defining the rule that the UE uses only the reference signal samples that happen no later than the reference resource is to ensure that the UE has enough time to process the reference signal measurement(s) and compute the corresponding CSI report.

[0051] A UE has limited capacity for how many simultaneous CSI calculations it can perform. A UE supporting a number NCPUof simultaneous CSI calculations is said to have NCPUCSI processing units. This capacity can be indicated by the UE to the network per component carrier (simultaneousCSI-SubReportsPerCC-rl8) and across all component carriers (simultaneousCSI-SubReportsAllCC-rl8) as part of UE capability reporting. The number of CSI processing units (CPUs) that are needed depends on the type of CSI. For example, report quantity CRI-RSRP-Index occupies one CPU while for reportQuantity ‘cri-RI-PMI-CQI’ more CPUs are needed. See 3GPP TS 38.214 Sec 5.2.1.6 for more details. The CPU framework includes rules for prioritization of CSI-RS processing in case the UE capacity is reached.

[0052] Another limitation for UEs is its capacity to measure on multiple different CSI-RS signals simultaneously (i.e., the number of simultaneously active CSI-RS resources that the UE can measure is limited by UE capability). In any slot, the UE is not expected to have more active CSI-RS ports or active CSI-RS resources in active bandwidth parts (BWPs) than reported by its capability. For example, a UE that is configured with a periodic CSI-RS counts the periodic CSI-RS as always active. This means that the UE can at any time receive a DCI triggering an aperiodic CSI report, and the UE can proactively buffer either the latest received CSI-RS measurements or computed CSI, so that it can be ready to report a CSI when receiving such an aperiodic CSI report trigger, see Figure 3. In the example of Figure 3, the UE needs to buffer either measurements of RS#1 or computed CSI based on measurements of RS#1 in case an aperiodic CSI report request is subsequently received. In this timeline, a DCI triggering an aperiodic CSI report comes after RS#1 ; and the time-domain reference resource comes after RS#1; hence the CSI report should be based on RS# 1.

[0053] Non-Zero Power (NZP) CSI-RS resources are counted as active or not active based on different criteria as defined in 3GPP TS 38.214 Sec. 5.2.1.6. One important aspect is that periodic CSI-RS are always counted as active, while semi-persistent and aperiodic CSI-RS are counted asP113067W001 9active for limited duration. Additional conditions for active resource counting concern for example sub-configurations and if the same resource is referenced from multiple CSI-RS resource settings.

[0054] There currently exist certain challenge(s). For LTM, a UE can be configured with a large number of Channel State Information (CSI) Reference Signals (CSI-RSs) for many different LTM candidate cells, both for the sake of LI -Reference Signal Received Power (RSRP) measurements and for the sake of early CSI- Acquisition. However, a UE has limited capacity to • measure CSI-RS for LTM candidates resources, and• process CSI-RS measurements (CPUs).

[0055] According to the current 3rdGeneration Partnership Project (3 GPP) specification, all configured periodic CSI-RS are counted as active. This approach is not feasible with LTM since there will be a very large number of periodic CSI-RS resources that can be configured to the UE for LTM use case. The limit for the UE capacity will quickly be reached. How a UE measures / processes CSI-RSs in the LTM use case is an open problem to be solved.

[0056] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. Embodiments of the present disclosure relate to any one or more of the following aspects:- UE indicating to the network its capability / capacity to measure and process CSI-RS of LTM Candidates,- Specification of which CSI-RS resources of LTM Candidate cells that are counted as active and should be measured by the UE,- Priority rules if UE capabilities for active CSI-RS resources or CSI processing units (CPUs) are exceeded.

[0057] Certain embodiments may provide one or more of the following technical advantage(s). With embodiments of the present disclosure, the UE behavior with respect to CSI-RS measurements and CSI processing is clarified. This clarification enables the network (e.g., the source cell of an LTM cell switch) to trigger the UE to perform measurements on one or more indicated LTM Candidate cells either before or during LTM Cell Switch.

[0058] Measurements on CSI-RS from a candidate cell can be used to speed up link adaptation in the candidate cell. The network will be able to choose modulation and coding scheme for the Physical Downlink Shared Channel (PDSCH), and aggregation level for Physical Downlink Control Channel (PDCCH) already from the first downlink (DL) transmissions in the candidate cell, without having to wait for the regular Channel Quality Indicator (CQI) reports.

[0059] The description herein refers to the term “L1 / L2 based inter-cell mobility” as used in the Work Item Description RP-234-36 in 3GPP, though it interchangeably also uses the termsP113067W001 10L1 / L2 mobility, Ll-mobility, LI based mobility, Ll / L2-centric inter-cell mobility, L1 / L2 intercell mobility L1 / L2 Triggered Mobility, Lower-layer triggered Mobility, or LTM. The basic principle is that the UE receives a lower layer signaling (e.g. a MAC CE) from the network indicating to the UE a change (or switch or activation) of included serving cell (e.g. change of Primary Cell (PCell), from a source to a target PCell), wherein a lower layer signaling is a message / signaling of a lower layer protocol (e.g. lower than RRC), which may be referred as a L1 / L2 intercell 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 Secondary Cell(s) (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 Master Cell Group (MCG) configuration). Before the UE receives the LTM cell switch command, the UE is configured by the network with one or more LTM candidate cells (e.g. reception of an RRC Reconfiguration message, with at least one LTM candidate cell configuration) A candidate cell configuration may include parameters in the Information Element (IE) CellGroupConfig per candidate cell and / or an embedded RRC Reconfiguration per candidate cell.

[0060] The term LTM cell switch procedure refers to the process of a UE changing its cell from a source cell to a target cell (which may be called herein a candidate cell or a neighbor 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 dynamic switch, LTM switch, (LTM) cell switch, (LTM) serving cell change, or (LTM) cell change. 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 Special Cell (SpCell) (e.g. change of PCell, or change of Primary Secondary Cell (PSCell)) and a change in SCells of the cell group (e.g. addition, modification and / or release of one or more SCells).

[0061] The LTM cell switch procedure may be triggered by the UE receiving an LTM cell switch command from the network. The source and target cells in an LTM cell switch procedure may be controlled by the same gNB, which sometimes is referred to as the intra-gNB case, or when the gNB uses a distributed Central Unit (CU) / Distributed Unit (DU) Radio Access Network (RAN) architecture, the intra-CU inter-DU case or the intra-CU intra-DU case (depending on whether the cells are controlled by the same DU or different DUs). When the source and target cells in an LTM cell switch procedure are controlled by different gNBs, this is sometimes referred to as the inter-gNB case, or inter-CU case, or sometimes known as an inter-CU LTM cell switch procedure.

[0062] The description herein refers to at least one LTM candidate cell configuration. This is also sometimes referred to as a configuration of an LTM candidate cell, which may be an RRC configuration, such as encapsulated in an RRC Reconfiguration message, that the UE receivesP113067W001 11when being configured with L1 / L2 Triggered Mobility. An 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 an 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 (or multiple 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).

[0063] 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 an 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).

[0064] An inter-CU LTM cell switch procedure, sometimes also referred to as inter-CU LTM or inter-gNB LTM, is an LTM cell switch procedure resulting in a change of serving cell, e.g. change of SpCell, PCell, PSCell, to an LTM candidate cell controlled by a different gNB than the source gNB or serving gNB of the UE when the execution LTM cell switch procedure was triggered (e.g. upon reception of the LTM cell switch command). From UE point of view, the actions performed during an inter-CU LTM cell switch procedure may be the same type of actions of an LTM cell switch procedure, but may also include additional actions, such as change of security key(s).

[0065] The description herein refers to inter Master Node (MN) L1 / L2 Triggered Mobility, inter-MN LTM, configuration of inter-MN LTM, execution of inter-MN LTM and an inter-MN LTM cell switch procedure. In the context of this disclosure, inter-MN LTM refers to inter-CU LTM, sometimes also referred to as inter-gNB LTM, handover or MCG mobility, when the UE is configured with dual connectivity, such as NR-Dual Connectivity (DC), and where the source cell and target cell are both part of the source and target MCG, respectively, and controlled by different CUs or different gNBs.

[0066] The term conditional LTM refers to L1 / L2 Triggered Mobility where the execution of the LTM cell switch is triggered by the UE when an execution condition, such as a layer 1, layer 2 or a layer 3 event, criterion or condition related to, for example, a radio measurement, is fulfilled. Upon the cell switch the UE applies a stored LTM candidate cell configuration.P113067W001 12

[0067] The description herein refers to an inter-CU LTM candidate cell configuration. An inter-CU LTM candidate cell configuration is an LTM candidate cell configuration which contains the configuration which the UE needs to start to operate accordingly when it performs an LTM cell switch procedure to an LTM candidate cell which is controlled by a different base station, e.g. gNB, from the current source base station e.g. serving gNB of the UE. In some cases, the UE may receive an inter-CU LTM candidate cell configuration during configuration of inter-MN LTM. In some cases, the UE may apply an inter-CU LTM candidate cell configuration during execution of inter-MN LTM.

[0068] An inter-CU LTM candidate cell configuration may be the same as an LTM candidate cell configuration but it may also include additional information than what is included in the LTM candidate cell configuration used for inter-CU cell switch. This additional information may be, for example:• Information to perform security key refresh, e.g. the RRC IE MasterKeyUpdate or a RRC IE RadioBearerConfig that includes SecurityConfig with Security AlgorithmConfig• Indication to perform Packet Data Convergence Protocol (PDCP) re-establishment.• Indication to perform a full configuration, e.g. the RRC field fullConfig

[0069] The description herein refers to a mobility procedure, configuration of a mobility procedure or execution of a mobility procedure. In the context of this disclosure, a mobility procedure may be L1 / L2 Triggered Mobility, LTM, inter-CU LTM, inter-MN LTM, L3 handover, PCell handover, conditional handover (CHO), conditional LTM, PSCell change or conditional PSCell Addition or Change (CP AC). The embodiments of the solutions described herein sometime uses the inter-MN LTM as the example. However, many of the examples may also be applied for other mobility procedures, for example, LTM, inter-CU LTM, conditional LTM or CHO.

[0070] Furthermore, the solution(s) disclosed herein is also applicable for Conditional LTM (CLTM), which may be viewed as a form of conditional reconfiguration. In CLTM, the UE is configured with an LTM candidate cell (denoted as a CLTM candidate cell), by receiving an LTM candidate cell configuration, as in legacy LTM, and called herein a Conditional LTM candidate cell configuration, and an associated execution condition, denoted CLTM execution condition. The CLTM execution condition associated to a CLTM candidate cell is associated to the assessment of lower layer measurements, such as Layer 1 (LI) RSRP and / or SS-RSRP, derived from SSBs and / or CSI-RSs of either the source cell and / or an CLTM candidate cell. Lower layer measurements, in this context, are measurements reported to support lower layer procedures like beam management, TCI state activations / deactivations, early timing advance (TA) acquisition, and link adaptation, and they aren't filtered based on Layer 3 (L3) parameters, though there may beP113067W001 13some filtering of these measurements based on lower layer parameters. The reception of CLTM execution condition may also involve receiving an indication of the condition and / or configuring it with parameters such as event identifier(s), offset(s), threshold(s), reference signal (RS) type, trigger quantity, time-to-trigger (TTT), and so forth.

[0071] When configured with CLTM, the UE evaluates the CLTM execution condition (referred to as Conditional LTM execution condition, LTM execution condition, or triggering condition) or a combination thereof. And, when the condition for a CLTM candidate cell is fulfilled, the UE performs a CLTM execution, which may be seen as a kind of LTM execution (but not triggered by the reception of an LTM cell switch command); this may also be considered as a kind of LTM cell switch, or Conditional LTM cell switch, or Conditional LTM execution. During the execution, the UE may apply a message, parts of a message, or at least one information element (IE), or perform a source cell switch or change. According to the methods outlined in the present disclosure, upon satisfaction of the execution condition(s), the UE initiates an LTM cell switch.

[0072] The description herein refers to a mobility configuration. When the UE has been configured with a mobility configuration, it may use the mobility configuration during preparation of a mobility procedure, including measurements (such as RSRP measurements on neighbor or serving cells), triggering and transmission of measurement reports, synchronization towards neighbor cells, evaluation of conditions (for conditional mobility, e.g. CHO), and during the execution of a mobility procedure (e.g. execution of an LTM cell switch procedure, execution of an inter-MN LTM cell switch procedure or execution of handover).

[0073] A mobility configuration may include one or multiple of the following type of elements where each element contains a configuration of one aspect of LTM, for example as follows:• LTM candidate cell configuration(s),• inter-CU LTM candidate cell configuration(s),• lower layer information, such as physical layer configuration, Medium Access Control (MAC) layer configuration or Radio Link Control (RLC) layer configuration, Cell Group configuration, serving cell configuration.• higher layer information, such as RRC protocol parameters, such as timer values, PDCP layer configuration, radio bearer configuration or measurement configuration• Configuration of measurements for LTM• Configuration for measurement reports for LTM• CSI resource configuration(s) for LTM• CSI report configuration for LTMP113067W001 14• Configurations of early synchronization procedures, such aso Configurations for DL pre-sync for LTM, such as configurations for early TCI state activationo Configurations for UL pre-sync for LTM, such as configurations for reception of PDCCH ordered triggered preamble transmission and reception of TA.• Configurations for the execution of an LTM cell switch procedure for a given LTM candidate cell configuration or inter-CU LTM candidate cell configuration (e.g., whether to perform random access procedure, whether to perform RLC reestablishment, or MAC reset, or PDCP recovery), a timer value, configured UL grants, dedicated RA preambles.• A configuration which the UE needs to start to operate accordingly when it performs an LTM cell switch procedure to an LTM candidate cell which is controlled by a different base station, e.g. gNB, from the current source base station e.g. serving gNB of the UE.• Information to perform security key refresh, e.g. the RRC IE MasterKeyUpdate or a RRC IE RadioBearerConfig that includes SecurityConfig with Security AlgorithmConfig. • Indication to perform a full configuration, e.g. the RRC field fullConfig.• Indication to perform L2 re-establishment, such as an indication to perform PDCP reestablishment for one or multiple bearers.

[0074] The term “subsequent LTM” sometimes also referred to a “subsequent LTM cell switch (procedures)” refers to that the UE performs a first LTM cell switch procedure from a source cell to a first target cell, then performs a second LTM cell switch procedure from the first target cell (which is now the new source cell) to a second target cell, and between the first and second LTM cell switch procedures there is no RRC reconfiguration of the UE. This implies also that the network does not add / remove / modify the LTM candidate cell configuration(s) or inter-CU LTM candidate cell configuration(s) in the UE between the two LTM cell switch procedures.

[0075] The description herein uses the term “cell” to identify a location (or coverage) on which the UE is located. However, the term “cell” can also be exchanged without any loss of meaning with the terms “radio resources”, “beams”, “TCI state”, or “TRS”. This is just to clarify that the present disclosure does not target specifically a scenario where there is a cell, but rather when a UE uses a set of source radio resources and need to switch to a target set of radio resources. In such a case, radio resource can also identify a set of configurations, field, parameters, or ASN.l structures or IES.

[0076] The description herein uses the term “early DL synchronization” to describe the action performed by the UE of pre-activating a TCI state of at least one LTM candidate cell configuration before performing an LTM cell switch execution. In this case, the TCI state on a given LTMP113067W001 15candidate cell is “activated in advance”, or “pre-activated”. Therefore, the terms “early DL synchronization”, or “early TCI state activation”, or “early TCI state pre-activation” can be exchanged in the description provided herein without any loss of meaning.

[0077] Moreover, the description herein uses the terms “first network node” and “second network node” to refer to a source cell / serving cell / source gNB-DU / Source DU (S-DU) and a candidate cell / candidate gNB-DU / C-DU respectively.

[0078] Figure 4 illustrates the operation of a UE 400 and a network node 402 (sometimes referred to herein as a “first network node” or “source network node” for an LTM cell switch), in accordance with embodiments of the present disclosure. Optional steps are represented by dashed lines or boxes. Further, while the steps are shown in Figure 4 as occurring in a particular order, the present disclosure is not limited thereto. The steps may be performed in any desired order unless explicated stated or otherwise required. The network node 402 may be a Radio Access Network (RAN) node such as, e.g., a base station (e.g., gNB) or a RAN node that implements part of the functionality of a base station (e.g., a Distributed Unit (DU) or Central Unit (CU) in a split architecture).

[0079] In the process of Figure 4, the UE 400 is configured with one or more LTM CSI-RS resource configurations and LTM Report configurations for early CSI acquisition in one or more LTM candidate cells. The process of Figure 4 enables the UE 400 to determine when and on which CSI-RS resources that the UE 400 is to perform measurement operations. As discussed below, this determination is based on any one or any combination of two or more of the following:• the UE 400 indicating to the network node 402 its capabilities for active CSI-RS resources of LTM candidate cells,• specification of which CSI-RS resources of LTM candidate cells are counted as active and should be measured,• prioritization (e.g., one or more priority rules) if UE capabilities for active CSI-RS resources or CSI processing units (CPU) are exceeded.

[0080] As illustrated in Figure 4, the UE 400 reports (i.e., sends), to the network node 402, capability information for activate CSI-RS resources of LTM candidate cells (step 403). This capability information includes information that indicates the UE’s capabilities with respect to at least one of the following:- How many active CSI-RS resources of LTM Candidate cells the UE 400 supports.o In one embodiment, the number of active CSI-RS resources of LTM Candidate cells the UE 400 supports is reported per LTM Candidate cell.P113067W001 16o In another embodiment, the number of active CSI-RS resources of LTM Candidate cells the UE 400 supports is reported across all LTM Candidate cells. o In another embodiment, the UE 400 reports the total number of active CSI-RS resource that it supports for serving cells and LTM Candidate Cells and any other cells.- How many active CSI-RS ports are within the active CSI-RS resources of LTM Candidate cells the UE 400 supports.o In one embodiment, the number of active CSI-RS ports within the active CSI-RS resources of LTM candidate cells is reported per LTM Candidate cell.o In another embodiment, the number of active CSI-RS ports within the active CSI- RS resources of LTM candidate cells is reported across all LTM candidate cells.

[0081] In one embodiment, in step 403, the UE 400 reports the number of active CSI-RS ports within the active CSI-RS resources of serving cells and LTM candidate cells and any other cell that the UE 400 supports. In other words, the UE reports 400 reports, to the network node 402, the UE’s capabilities with respect to at least one of the following:- In one embodiment, the number of active CSI-RS resources the UE 400 supports across all LTM Candidate cells or all LTM Candidate cells and serving cells, is reported .- In one embodiment, the number of active CSI-RS ports the UE 400 supports across all LTM Candidate cells or all LTM Candidate cells and serving cells, is reported .o across all serving cells, LTM candidate cells and other cells.

[0082] The UE 400 receives, from the network node 402, CSI report configurations for cells including one or more (preferably multiple) LTM candidate cells (step 404). In one embodiment, the cells for which the CSI report configurations are received include one or more serving cells of the UE 400 and one or more neighbor cells, including LTM Candidate cells. According to the report configurations and CSI report requests received from the network, the UE 400 processes CSI calculations up to what is allowed by its capability.

[0083] The UE 400 determines which LTM Candidate Cell CSI-RS resources and / or ports should be counted as active and be measured on (step 405). In one embodiment, this determination is based on if any one or more of the following conditions apply:- The CSI-RS resource is periodic (e.g., the CSI-RS resource is counted as active if the CSI- RS resource is periodic).- If the CSI-RS is semi-persistent, it is counted as active when it is activated via a MAC CE until the semi-persistent CSI-RS is deactivated via another MAC CE.P113067W001 17- If the CSI-RS is aperiodic, it is counted as active starting from when the aperiodic CSI-RS is triggered until the corresponding CSI is reported.- The CSI-RS is configured in an LTM resource set which is associated with an LTM report configuration for early CSI acquisition.- A TCI-State of the LTM Candidate cell of the CSI-RS resource is activated.- The UE has received a PDCCH order targeting the LTM Candidate cell of the CSI-RS. - An LTM Cell Switch Command MAC CE is received, targeting the LTM Candidate cell of the CSI-RS resource

[0084] The UE 400 performs CSI-RS measurements for active LTM candidate cells, up to its capability and, optionally, according to a prioritization (step 406). In one embodiment, the UE performs measurements on active CSI-RS resources of LTM candidate cells up to a limit (e.g., the actual or reported UE capability) (step 406A). In the case that the UE 400 is configured with more active CSI-RS resources than its active resource count capability allows, the UE 400 performs measurements up to the UE’s capability, according to a prioritization. The prioritization is determined based on any one or more of the following:- CSI-RS resources for beam-management are prioritized lower than CSI-RS resources for early CSI Acquisition,- CSI-RS resources of an LTM candidate with an activated TCI state is prioritized higher than a CSI-RS resources of an LTM candidate cell with no activated TCI state.- A set of CSI-RS resources who has same source RS as the activated TCI state are prioritized for the active resource counting than the other CSI-RS resources of the same cell.- A first CSI-RS resource of an LTM candidate with a first activated TCI state is prioritized higher than a second CSI-RS of an LTM candidate with a second activated TCI state, where the first TCI state was activated more recently (later) than the second TCI state- In a given time window, the prioritization is applied maximum of N1 number of times.That means that, if the N1 is 1, A first CSI-RS of an LTM candidate with a first activated TCI state is prioritized higher than a second CSI-RS of an LTM candidate with a second activated TCI state, where the first TCI state was activated earlier than the second TCI state. If N1 is 2, UE apply prioritization for the TCI state which was activated first and second, a first CSI-RS of an LTM candidate with a first activated TCI state and second CSI-RS of an LTM candidate with a second activated TCI state are prioritized higher than a third CSI-RS of an LTM candidate with a third activated TCI state, where the first TCIP113067W001 18state and second were activated earlier than the second TCI state. This may be essential for the UE power saving and NW not triggering too frequent TCI state activations.- CSI-RSs are prioritized according to the time domain behavior of the resource. A periodic CSI-RS has a higher priority, a semi-persistent CSI-RS has a next higher priority, and an aperiodic CSI-RS has the lower priority.

[0085] In addition or alternatively, the UE 400 performs the measurements on a number of CSI-RS ports within the active CSI-RS resources (or the prioritized activate CSI-RS resources) up to a limit (e.g., a reported or actual limit) (step 406B).

[0086] The UE 400 receives, from the network node 402 (e.g., a serving cell), an LTM Cell Switch Command MAC CE (LTM-CSC) (step 408). The LTM-CSC indicates one of the configured LTM Candidate cells as the target cell. Upon reception of LTM-CSC, the UE 400 performs one or more actions (step 410). These one or more actions include any one or more of the following actions:- The UE 400 keeps LTM resource configurations and LTM report configurations for early CSI acquisition in the Target cell.- The UE 400 counts as active the CSI-RS resources configured as part of the LTM resource configurations in the Target cell and continues to measure on any CSI-RS resources for early CSI acquisition in the target cell which are already active. Buffered measurements on active CSI-RS resources of the target cell that were performed before LTM-CSC are kept.- If there are periodic CSI-RSs configured for early CSI-acquisition in the target cell which are not already counted as active, the UE 400 starts counting those periodic CSI-RSs as activate.- If there are aperiodic CSI-RSs configured for early CSI-acquisition in the target cell which are not already counted as active, the UE 400 starts counting those aperiodic CSI-RSs as activate after receiving a DCI that triggers those aperiodic CSI-RSs.- If there are semi-persistent CSI-RSs configured for early CSI-acquisition in the target cell which are not already counted as active, the UE 400 starts counting those semi-persistent CSI-RSs as activate after receiving a MAC CE that activates those semi-persistent CSI- RSs.

[0087] The UE 400, together with the network node 402 (and optionally a second network node in the case of an inter-network node cell switch) perform the LTM cell switch to the target cell (step 412). In one embodiment, the UE 400 continues to measure on active CSI-RS resources during the execution of LTM Cell switch (step 414).P113067W001 19

[0088] In one embodiment, after completion of the LTM Cell Switch, the UE 400, continues to count as active the CSI-RS resources for early CSI-acquisition in the new target cell and continues to perform measurements on them at least until the UE 400 has sent a CSI measurement report to the target cell (step 416).

[0089] Figure 5 illustrates the operation of a UE 500 and a network node 502 (sometimes referred to herein as a “first network node” or “source network node” for an LTM cell switch), in accordance with another embodiment of the present disclosure. Optional steps are represented by dashed lines or boxes. Further, while the steps are shown in Figure 5 as occurring in a particular order, the present disclosure is not limited thereto. The steps may be performed in any desired order unless explicated stated or otherwise required. The network node 502 may be a RAN node such as, e.g., a base station (e.g., gNB) or a RAN node that implements part of the functionality of a base station (e.g., a DU or CU in a split architecture).

[0090] As illustrated in Figure 5, the UE 500 receives, from the network node 502, CSI report configurations for cells including one or more (preferably multiple) LTM candidate cells or a target cell for an LTM cell switch (step 504). In one embodiment, the cells for which the CSI report configurations are received include one or more serving cells of the UE 400 and one or more neighbor cells, including LTM Candidate cells and / or a target cell for an LTM cell switch. According to the report configurations and CSI report requests received from the network, the UE 500 processes CSI calculations up to what is allowed by its capability (506). In step 506, the UE 500 prioritizes CSI for early LTM CSI acquisition according to any one or more of the following conditions:- Before LTM-CSC is received, CSI for early LTM CSI acquisition should be prioritized for LTM Candidate cells with an activated TCI state and or that LTM Candidate cells for which the UE has received a PDCCH order for early UL sync.- After LTM-CSC is received and before completion of LTM cell switch completion, CSI for early LTM CSI acquisition should be prioritized for the target cell.- After completion of LTM cell switch execution, CSI for early LTM CSI acquisition should be prioritized for the new source cell.

[0091] Figure 6 illustrates the operation of a UE 600 and a network node 620, referred to herein as “source network node”, and a network node 640, referred to herein as “target network node”\, for an LTM cell switch, in accordance with another embodiment of the present disclosure. Optional steps are represented by dashed lines or boxes.

[0092] Referring to Figure 6, the serving cell (provided by the source network node 620) of the UE 600 configures the UE 600 with early CSI acquisition which includes one or more LTMP113067W001 20candidate cells at step 602. After receiving LI RSRP report from the UE 600 at step 604, or some other possible triggering condition satisfied, the source network node 620 can make quick decision on cell switch, switching the serving cell of the UE 600 to another cell 640 with the one or more LTM candidate cells. Unlike the legacy rules that as long as being configured with the early CSI acquisition, the LTM candidate cells will be measured, in this embodiment, until the LTM CELL SWITCH COMMAND MAC CE is received does the UE starts to perform CSI-RS measurement on CRI / CQI / PMI and / or RI at step 608. Therefore, CSI report can be sent, at step 610, so that link adaptation in the new serving cell 640 can be performed as early as possible.

[0093] At step 601, the UE 600 may report its capability for early CSI acquisition to its serving cell 620 prior to the configuration, so that the configuration sent at step 602 can be determined or justified based on the UE’s capacity, such as the maximum number of CSI-RS resources and / or ports to be measured simultaneously, or maximum number of CSI processing units that the UE 600 supports for CRI, CQI, PMI, and / or RI measurements on CSI-RS.

[0094] At step 608, in case that serving cell has no information on UE’s capability for early CSI acquisition, or the configuration anyhow assigns more CSI-RS resources / ports than UE’s capability, or some other predetermined maximum number of CSI-RS resources / ports, the UE 600 needs to apply prioritization on which CSI-RS resources / ports to be prioritized. Detailed prioritization information is discussed in aforementioned embodiments thus will not be elaborated.

[0095] Figure 7 shows an example of a communication system 700 in which embodiments of the present disclosure may be implemented. The UE 400, 500 or 600 may be one of the UEs 712 of Figure 7, and the network node 402, 504, 620 or 640 may be one of the access network nodes 710.

[0096] In the example, the communication system 700 includes a telecommunications network 702 that includes an access network 704, such as a radio access network (RAN), and a core network 706, which includes one or more core network nodes 708. The access network 704 includes one or more access network nodes or base stations of various types, access network nodes 710A and 710B are depicted (which may be collectively referred to as network nodes 710), or any other similar 3rd Generation Partnership Project (3GPP) access nodes or non-3GPP access points (APs). Some embodiments of the access network 704 may include more than one access network technology. The network nodes 710 of access network 704 facilitate direct or indirect connection of wireless devices, also referred to as user equipments (UEs), such as by connecting UEs 712A, 712B, 712C, and 712D (one or more of which may be generally referred to as UEs 712) to the core network 706 over one or more wireless connections.P113067W001 21

[0097] Moreover, 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 telecommunications network 702 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a network node in the telecommunications network 702 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other network nodes to implement one or more functionalities of any network node in the telecommunications network 702, including one or more access network nodes 710 and / or core network nodes 708.

[0098] The network nodes 710 facilitate direct or indirect connection of one or more UEs 712 to the core network 706 over one or more wireless connections. 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 700 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 700 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0099] The UEs 712 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 710 and other communication devices. Similarly, the network nodes 708, 710 are arranged, capable, configured, and / or operable to communicate directly or indirectly (e.g., via other devices of telecommunications network 702) with the UEs 712 and / or with other network nodes or equipment in the telecommunications network 702 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in the telecommunications network 702. More specifically, UEs 712 may send messages, data, and / or other signals to network nodes 708, 710 or other elements of the telecommunications network 702 by transmitting such signals to the relevant device directly without the signals passing through any intervening devices or by transmitting such signals to the relevant device indirectly through an intervening device (or multiple intervening devices) that then transmit the signal to the relevant device. Similarly, network nodes 708, 710 may send messages, data, and other signals toP113067W001 22UEs 712, other network nodes 708, 710, and other devices in telecommunications network 702 directly or indirectly. As one specific example, a core network node 708 may transmit a particular message to a UE 712 by transmitting the message to an access network node 710 that will then transmit the message to the intended UE 712. Similarly, a core network node 708 may receive a particular message from a UE 712 by receiving the message from an access network node 710 that itself received the message from the UE 712.

[0100] In the depicted example, the core network 706 connects elements of the access network 704 (e.g., one or more of the network nodes 710) to one or more host computing systems, such as host 716. 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 706 includes one or more core network nodes (e.g., core network node 708) of various types, one or more of which may be generally referred to as network nodes 708. Network nodes 708 are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, access network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 708. Example core network nodes provide 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).

[0101] The host 716 may be under the ownership or control of a service provider other than an operator or provider of the access network 704 and / or the telecommunications network 702. The host 716 may be operated by the service provider or on behalf of the service provider. The host 716 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.

[0102] As a whole, the communication system 700 of Figure 7 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system 700 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 Long Term Evolution (LTE), and / or otherP113067W001 23suitable 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards. Moreover, the communication system 700 may be configured to support multiple different standards, protocols, or other rule sets, with individual components supporting all of the relevant rule sets or with different components or sub-systems within the communication system 700 supporting different standards, protocols, or rule sets.

[0103] As one example, in certain embodiments, access network 704 may contain some access network nodes 710 that support 3 GPP radio access technologies (RAT), such as LTE or NR, while other access network nodes 710 support (or the same access network nodes 710 additionally support) non-3GPP RATs, such as Wi-Fi or a proprietary RAT. As another example, telecommunications network 702 may support multiple generations of related communication standards (e.g., 4G and 5G 3GPP communication standards) and, as a result, may include an access network 704 and / or a core network 706 that supports multiple different standard generations or may include multiple access networks 704 and / or multiple core networks 706 with individual networks 704, 706 supporting different standard generations.

[0104] Telecommunications network 702 may support network slicing to provide different logical networks to different devices that are connected to the telecommunications network 702. For example, the telecommunications network 702 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.

[0105] In some examples, one or more of the UEs 712 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 704 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 704. 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).

[0106] In the example, the hub 714 communicates with the access network 704 to facilitate indirect communication between one or more UEs (e.g., UE 712C and / or 712D) and network nodes (e.g., network node 710B). In some examples, the hub 714 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 714 may be a broadband router enabling access to the core network 706 for the UEs. As another example, the hub 714 may be a controller that sends commands or instructionsP113067W001 24to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 710, or by executable code, script, process, or other instructions in the hub 714.

[0107] Figure 8 shows a wireless device 800, which may be configured to operate in communication system 700 of Figure 7. The wireless device 800 may be alternatively referred to as a UE 800, like a UE 712 within the context of communication system 700, or as a station (STA) 800 or as a non-access-point station (non-AP STA) 800, in accordance with respective embodiments. As used herein, a wireless device refers to a device capable, configured, arranged and / or operable to communicate wirelessly with network nodes and / or other wireless devices. Examples of a wireless device 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 device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), smart device, wireless customerpremise equipment (CPE), vehicle, vehicle-mounted or vehicle embedded / integrated wireless device, and wireless terminal. Other examples include any type of 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.

[0108] A wireless device 800 may support device-to-device (D2D) communication, for example by implementing a 3GPP 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, wireless device 800 may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, wireless device 800 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, wireless device 800 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).

[0109] In particular embodiments, wireless device 800 includes processing circuitry 802 that is operatively coupled via a bus 804 to an input / output interface 806, a power source 808, a memory 810, a communication interface 812, and / or any other component, or any combination thereof. Certain embodiments of wireless device 800 may include all or a subset of the components shown in Figure 8. The level of integration between the components may vary from one embodiment of wireless device 800 to another. In general, in a particular embodiment of wireless device 800, processing circuitry 802, input / output interface 806, power source 808, memory 810,P113067W001 25and communication interface 812 may, in whole or in part, represent or include physical components common to or shared by one or more of the other elements of wireless device 800. Further, certain embodiments of wireless devices 800 may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0110] The processing circuitry 802 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 810. The processing circuitry 802 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 802 may include multiple central processing units (CPUs).

[0111] In the example, the input / output interface 806 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 wireless device 800.

[0112] In some embodiments, the power source 808 is structured as a battery 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 to supply power to circuitry or to charge an associated battery. The power source 808 may further include power circuitry for delivering power from the power source 808 itself, and / or an external power source, to the various parts of wireless device 800 via input circuitry or an interface such as an electrical power cable. Power source 808 may perform any formatting, converting, or other modification to make accessible power suitable for the respective components of the wireless device 800 to which power is supplied.

[0113] The memory 810 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 810 includes one or more programs 814, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 816. The memory 810 may store, for use by wireless device 800, any of a variety of various operating systems or combinations of operating systems.P113067W001 26

[0114] The processing circuitry 802 may be configured to communicate with an access network or other network via or using the communication interface 812. The communication interface 812 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 822. The communication interface 812 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 wireless device or a network node in an access network). Each transceiver may include a transmitter 818 and / or a receiver 820 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 818 and receiver 820 may be coupled to one or more antennas (e.g., antenna 822) and may share circuit components, software, or firmware, or alternatively be implemented separately.

[0115] In the illustrated embodiment, communication functions of the communication interface 812 may include cellular communication, Wi-Fi communication (e.g., according to an IEEE 802.11 family standard), 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 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 / intemet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0116] In particular embodiments, wireless device 800 may provide an output of data captured via a sensor, through its communication interface 812, via a wireless connection to a network node, and / or in any appropriate manner. Data captured by sensors of a wireless device 800 can be communicated through a wireless connection to a network node via another wireless device 800. In particular embodiments, such 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).

[0117] As another example, wireless device 800 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, theP113067W001 27motor, or the switch may change. For example, wireless device 800 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.

[0118] Wireless device 800, 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, wearable technology, extended industrial application and healthcare. In particular embodiments, wireless device 800 represents an loT device that 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 example embodiment of wireless device 800 shown in Figure 8.

[0119] As yet another specific example, in an loT scenario, wireless device 800 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 wireless device and / or a network node. Wireless device 800 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, wireless device 800 may implement the 3GPP NB-IoT standard. In other scenarios, wireless device 800 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.

[0120] Figure 9 shows a network node 900 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 telecommunications network. In accordance with respective embodiments, network node 900 may be configured to operate in communication system 700 of Figure 7, like network nodes 708 or 710. 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)), O-RAN nodes or components of an O-RAN node (e.g., O-RU, O-DU, O-CU).

[0121] Network nodes 900 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. Network node 900 may be a relay node or a relay donor node controlling a relay. Network nodes 900 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 O-RAN access node) and / or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts ofP113067W001 28a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

[0122] Other examples of network nodes 900 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).

[0123] In particular embodiments, network node 900 includes a processing circuitry 902, a memory 904, a communication interface 906, and a power source 908. In general, in a particular embodiment of network node 900, processing circuitry 902, memory 904, communication interface 906, and power source 908 may, in whole or in part, represent or include physical components common to or shared by one or more of the other elements of network node 900.

[0124] The network node 900 may be composed of multiple distinct network entities (e.g., a NodeB entity and an RNC entity, or a BTS entity and a BSC entity, etc.), which may each have or utilize their own respective physical components. In certain scenarios in which the network node 900 comprises multiple such entities (e.g., BTS and BSC), one or more of the separate entities 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 900 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memories 904 or portions of memory 904 for different RATs) and some components may be reused (e.g., a same antenna 910 may be shared by different RATs). The network node 900 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 900, for example GSM, WCDMA, LTE, NR, Wi-Fi (e.g., according to an IEEE 802.11 family standard), 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 900.

[0125] The processing circuitry 902 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 operableP113067W001 29to provide, either alone or in conjunction with other components, such as the memory 904, to provide network node 900 functionality.

[0126] In some embodiments, the processing circuitry 902 includes a system on a chip (SOC). In some embodiments, the processing circuitry 902 includes one or more of radio frequency (RF) transceiver circuitry 912 and baseband processing circuitry 914. In some embodiments, the RF transceiver circuitry 912 and the baseband processing circuitry 914 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 912 and baseband processing circuitry 914 may be on the same chip or set of chips, boards, or units.

[0127] The communication interface 906 is used in wired or wireless communication of signaling and / or data with UEs, other network nodes, and / or any other network equipment. In the illustrated embodiment, communication interface 906 comprises port(s) / terminal(s) 916 to send and receive data, for example to and from a network over a wired connection. In particular embodiments, network node 800 may be capable of wireless communication and communication interface 906 may also include radio front-end circuitry 918 that may be coupled to, or in certain embodiments a part of, an antenna 910. Particular embodiments of radio front-end circuitry 918 include filter(s) 920 and amplifier(s) 922. The radio front-end circuitry 918 may be connected to an antenna 910 and processing circuitry 902. The radio front-end circuitry may be configured to condition signals communicated between antenna 910 and processing circuitry 902. The radio front-end circuitry 918 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 918 may convert the digital data into a radio signal(s) having the appropriate channel and bandwidth parameters using a combination of filters 920 and / or amplifiers 922. The radio signal(s) may then be transmitted via the antenna 910. Similarly, when receiving data, the antenna 910 may collect radio signals which are then converted into digital data by the radio front-end circuitry 918. The digital data may be passed to the processing circuitry 902. In other embodiments, the communication interface may comprise different components and / or different combinations of components.

[0128] In certain alternative embodiments, network node 900 may be capable of wireless communication but does not include separate radio front-end circuitry 918, instead, the processing circuitry 902 includes radio front-end circuitry and is connected to the antenna 910. Similarly, in some embodiments, all or some of the RF transceiver circuitry 912 is part of the communication interface 906. In still other embodiments, the communication interface 906 includes one or more ports or terminals 916, the radio front-end circuitry 918, and the RF transceiver circuitry 912, asP113067W001 30part of a radio unit (not shown), and the communication interface 906 communicates with the baseband processing circuitry 914, which is part of a digital unit (not shown).

[0129] The antenna 910 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 910 may be coupled to the radio front-end circuitry 918 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 910 is separate from the network node 900 and connectable to the network node 900 through one or more interfaces or ports.

[0130] The antenna 910, communication interface 906, and / or the processing circuitry 902 may be configured to perform some or all of the receiving operations and / or obtaining operations described herein as being performed by the network node 900. Any information, data, and / or signals may be received from a UE, another network node, and / or any other network equipment. Similarly, the antenna 910, the communication interface 906, and / or the processing circuitry 902 may be configured to perform some or all of the transmitting or sending operations described herein as being performed by the network node 900. Any information, data and / or signals may be transmitted to a UE, another network node, and / or any other network equipment.

[0131] The power source 908 provides power to the various components of network node 900 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 908 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 900 with power for performing the functionality described herein. For example, the network node 900 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 908. As a further example, the power source 908 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.

[0132] Embodiments of the network node 900 may include additional components beyond those shown in Figure 9 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 subject matter described herein. For example, the network node 900 may include user interface equipment to allow input of information into the network node 900 and to allow output of information from the network node 900. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 900.P113067W001 31

[0133] Although the computing devices described herein (e.g., UEs, network nodes, hosts) 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, which may 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.

[0134] 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.

[0135] Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.P113067W001 32EMBODIMENT EXAMPLESGroup A Embodiments1. A method performed by a User Equipment, UE, (400) for early Channel State Information (CSI) acquisition in one or more Layer 1, LI, / Layer 2, L2, Triggered Mobility, LTM, candidate cells, the method comprising any one or more of the following:transmitting (403), to a network node (402), capability information that indicates one or more capabilities of the UE (400) related to active CSI Reference Signal, CSI-RS, resources of LTM candidate cells;determining (405) which CSI-RS resources of one or more configured LTM candidate cells are counted as active CSI-RS resources to be measured by the UE (400);performing (406) CSI-RS measurements for the active CSI-RS resources on the configured LTM candidate cells, up to a certain limit, and according to a certain prioritization.2. The method of embodiment 1, wherein the certain prioritization is applied if the active CSI-RS resources exceed the certain limit.3. The method of embodiment 1 or 2, wherein the certain limit is a limit on a number of active CSI-RS resources or a number of CSI processing units supported by the UE (400) (e.g., reported in the capability information).4. The method of any of embodiments 1 to 3, wherein the capability information comprises information that indicates a number of active CSI-RS resources of LTM candidate cells the UE (400) supports.5. The method of embodiment 4, wherein the number of active CSI-RS resources of LTM candidate cells the UE (400) supports is reported, in the capability information, per LTM candidate cell.6. The method of embodiment 4, wherein the number of active CSI-RS resources of LTM candidate cells the UE (400) supports is reported, in the capability information, across all (configured) LTM candidate cells.7. The method of embodiment 4, wherein the UE (400) reports, in the capability information, a total number of active CSI-RS resource that the UE (400) supports a plurality of cells comprising one or more serving cells of the UE (400) and the LTM candidate cells configured for the UE (400) and, optionally, one or more other cells.8. The method of any of embodiments 1 to 7, wherein the capability information comprises information that indicates a number of active CSI-RS ports within the active CSI-RS resources of LTM candidate cells the UE (400) supports.9. The method of embodiment 8, wherein the number of active CSI-RS ports within the activeP113067W001 33CSI-RS resources of LTM candidate cells is reported, in the capability information, per LTM candidate cell.10. The method of embodiment 8, wherein the number of active CSI-RS ports within the active CSI-RS resources of LTM candidate cells is reported, in the capability information, across all LTM candidate cells.11. The method of embodiment 8, wherein the number of active CSI-RS ports within the active CSI-RS resources of serving cells and LTM candidate cells and any other cell is reported across all serving cells, LTM candidate cells, and other cells.12. The method of any of embodiments 1 to 11, wherein performing (406) the CSI-RS measurements for the active CSI-RS resources on the configured LTM candidate cells comprises performing (406 A) the CSI-RS measurements for the active CSI-RS resources on the configured LTM candidate cells up to the certain limit and optionally according to the certain prioritization.13. The method of any of embodiments 1 to 11, wherein performing (406) the CSI-RS measurements for the active CSI-RS resources on the configured LTM candidate cells comprises performing (406A) the CSI-RS measurements on a number of active CSI-RS ports within the active CSI-RS resources of the LTM candidate cells up to the certain limit and optionally according to the certain prioritization.14. The method of any of embodiments 1 to 13, wherein the capability information comprises either or both of the following:- the number of active CSI-RS resources the UE supports across all LTM Candidate cells or all LTM Candidate cells and serving cells;- the number of active CSI-RS ports the UE supports across all LTM Candidate cells or all LTM Candidate cells and serving cells.15. The method of any of embodiments 1 to 14, wherein determining (405) which CSI-RS resources of the configured LTM candidate cells are counted as active CSI-RS resources to be measured by the UE (400) comprises determining which CSI-RS resources and ports of the LTM Candidate Cell are to be counted as active and be measured on based on if any one or more of the following conditions apply- The CSI-RS resource is periodic.- If the CSI-RS is semi-persistent, it is counted as active when it is activated via a MAC CE until the semi-persistent CSI-RS is deactivated via another MAC CE.- If the CSI-RS is aperiodic, it is counted as active starting from when the aperiodic CSI-RS is triggered until the corresponding CSI is reported.P113067W001 34- The CSI-RS is configured in an LTM resource set which is associated with an LTM report configuration for early CSI acquisition.- A TCI-State of the LTM Candidate cell of the CSI-RS resource is activated.- The UE has received a PDCCH order targeting the LTM Candidate cell of the CSI-RS - An LTM Cell Switch Command MAC CE is received, targeting the LTM Candidate cell of the CSI-RS resource16. The method of any of embodiments 1 to 15, further comprising receiving (408) an LTM cell switch command (e.g., an LTM Cell Switch Command MAC CE) from the network node (402), wherein the LTM cell switch command indicates one of the configured LTM candidate cells as a target cell for the LTM cell switch.17. The method of embodiment 16, further comprising, upon reception of the LTM cell switch command, performing (step 410) one or more actions, the one or more actions comprising any one or more of the following:- The UE keeps LTM resource configurations and LTM report configurations for early CSI acquisition in the Target cell.- The UE counts as active the CSI-RS resources configured as part of the LTM resource configurations in the Target cell and continues to measure on any CSI-RS resources for early CSI acquisition in the target cell which are already active. Buffered measurements on active CSI-RS resources of the target cell that were performed before LTM-CSC are kept.- If there are periodic CSI-RSs configured for early CSI-acquisition in the target cell which are not already counted as active, the UE starts counting those periodic CSI-RSs as activate. - If there are aperiodic CSI-RSs configured for early CSI-acquisition in the target cell which are not already counted as active, the UE starts counting those aperiodic CSI-RSs as activate after receiving a DCI that triggers those aperiodic CSI-RSs.- If there are semi-persistent CSI-RSs configured for early CSI-acquisition in the target cell which are not already counted as active, the UE starts counting those semi-persistent CSI- RSs as activate after receiving a MAC CE that activates those semi-persistent CSI-RSs.18. The method of any of embodiments 1 to 17, further comprising continuing (414) to measure on active CSI-RS resources during execution of LTM Cell switch.19. The method of any of embodiments 1 to 18, further comprising, after completion of LTM Cell switch, continuing (416) to count as active the CSI-RS resources for early CSI-acquisition in the target cell and continuing (416) to perform measurements on them at least until the UE has sent a CSI measurement report to the target cell.P113067W001 3520. The method of any of embodiments 1 to 18, wherein the UE is configured with more CSI-RS resources that the certain limit allows, and performing (406) the CSI-RS measurements for the active CSI-RS resources on the configured LTM candidate cells, up to the certain limit, comprises performing (406) the CSI-RS measurements for the active CSI-9RS resources on the configured LTM candidate cells, up to the certain limit, according to a certain prioritization.21. The method of embodiment 20, wherein the prioritization is determined based on any one or more of the following:- CSI-RS resources for beam-management are prioritized lower than CSI-RS resources for early CSI Acquisition,- CSI-RS resources of an LTM candidate with an activated TCI state is prioritized higher than a CSI-RS resources of an LTM candidate cell with no activated TCI state.- A set of CSI-RS resources who has same source RS as the activated TCI state are prioritized for the active resource counting than the other CSI-RS resources of the same cell.- A first CSI-RS resource of an LTM candidate with a first activated TCI state is prioritized higher than a second CSI-RS of an LTM candidate with a second activated TCI state, where the first TCI state was activated more recently (later) than the second TCI state- In a given time window, the prioritization is applied maximum of N1 number of times.That means that, if the N1 is 1, A first CSI-RS of an LTM candidate with a first activated TCI state is prioritized higher than a second CSI-RS of an LTM candidate with a second activated TCI state, where the first TCI state was activated earlier than the second TCI state. If N1 is 2, UE apply prioritization for the TCI state which was activated first and second, a first CSI-RS of an LTM candidate with a first activated TCI state and second CSI-RS of an LTM candidate with a second activated TCI state are prioritized higher than a third CSI-RS of an LTM candidate with a third activated TCI state, where the first TCI state and second were activated earlier than the second TCI state. This may be essential for the UE power saving and NW not triggering too frequent TCI state activations.- CSI-RSs are prioritized according to the time domain behavior of the resource. A periodic CSI-RS has a higher priority, a semi-persistent CSI-RS has a next higher priority, and an aperiodic CSI-RS has the lower priority.22. A method performed by a User Equipment, UE, (500) for early Channel State Information (CSI) acquisition in one or more Layer 1, LI, / Layer 2, L2, Triggered Mobility, LTM, candidate cells, the method comprising any one or more of the following:P113067W001 36receiving (504), from a network node (502), CSI report configurations for one or more cells comprising one or more LTM candidate cells and / or a target cell for an LTM cell switch; and performing (506) CSI-RS measurements and computing (506) CSI for early LTM CSI acquisition according to a certain prioritization.23. The method of embodiment 22, wherein the certain prioritization is according to any one or more of the following:- Before an LTM-CSC is received, CSI for early LTM CSI acquisition is prioritized for LTM Candidate cells with an activated TCI state and / or for LTM Candidate cells for which the UE has received a PDCCH order for early UL sync;- After an LTM-CSC is received and before completion of LTM cell switch, CSI for early LTM CSI acquisition is prioritized for a target cell of the LTM cell switch;- After completion of LTM cell switch execution, CSI for early LTM CSI acquisition is prioritized for a new source cell.24. The method of any of the previous embodiments, further comprising:providing user data; andforwarding the user data to a host via the transmission to the network node.Group B Embodiments25. A method performed by a network node, the method comprising:receiving (403), from a User Equipment, UE, (400), capability information that indicates one or more capabilities of the UE (400) related to active CSI Reference Signal, CSI-RS, resources of LTM candidate cells;26. The method of embodiment 25, wherein the capability information comprises information that indicates a number of active CSI-RS resources of LTM candidate cells the UE (400) supports.27. The method of embodiment 26, wherein the number of active CSI-RS resources of LTM candidate cells the UE (400) supports is reported, in the capability information, per LTM candidate cell.28. The method of embodiment 26, wherein the number of active CSI-RS resources of LTM candidate cells the UE (400) supports is reported, in the capability information, across all (configured) LTM candidate cells.29. The method of embodiment 25, wherein the UE (400) reports, in the capability information, a total number of active CSI-RS resource that the UE (400) supports a plurality of cells comprising one or more serving cells of the UE (400) and the LTM candidate cells configured for the UE (400)P113067W001 37and, optionally, one or more other cells.30. The method of any of embodiments 25 to 29, wherein the capability information comprises information that indicates a number of active CSI-RS ports within the active CSI-RS resources of LTM candidate cells the UE (400) supports.31. The method of embodiment 30, wherein the number of active CSI-RS ports within the active CSI-RS resources of LTM candidate cells is reported, in the capability information, per LTM candidate cell.32. The method of embodiment 30, wherein the number of active CSI-RS ports within the active CSI-RS resources of LTM candidate cells is reported, in the capability information, across all LTM candidate cells.33. The method of embodiment 30, wherein the number of active CSI-RS ports within the active CSI-RS resources of serving cells and LTM candidate cells and any other cell is reported across all serving cells, LTM candidate cells, and other cells.34. The method of embodiment 25, wherein the capability information comprises either or both of the following:- the number of active CSI-RS resources the UE supports across all LTM Candidate cells or all LTM Candidate cells and serving cells;- the number of active CSI-RS ports the UE supports across all LTM Candidate cells or all LTM Candidate cells and serving cells.35. The method of any of the previous embodiments, further comprising:obtaining user data; andforwarding the user data to a host or a user equipment.Group C Embodiments36. A wireless device comprising:processing circuitry configured to perform any of the operations of any of the Group A embodiments; anda power source configured to supply power to the processing circuitry.37. A network node comprising:processing circuitry configured to perform any of the operations of any of the Group B embodiments;a power source circuitry configured to supply power to the processing circuitry.38. A wireless device comprising:one or more antennas;P113067W001 38communication interface connected to the one or more antennas and to processing circuitry;the processing circuitry being configured to perform any of the operations of any of the Group A embodiments;an input interface connected to the processing circuitry and configured to allow input of information into the UE to be processed by the processing circuitry;an output interface connected to the processing circuitry and configured to output information from the UE that has been processed by the processing circuitry; anda power source connected to the processing circuitry and configured to supply power to the UE.

Claims

P113067W001 39CLAIMS1. A method performed by a user equipment, UE, the method comprising:receiving a configuration for early channel state information, CSI, acquisition, the configuration including one or more layer- l / layer-2 triggered mobility, LTM, candidate cells;receiving a command for LTM cell switch to a target cell, wherein the target cell is one of the one or more LTM candidate cells; andstarting to perform CSI reference signal, CSI-RS, measurements upon receiving the command, the CSI-RS measurements including at least one of: channel rank indicator, CRI, channel quality indicator, CQI, precoding matrix indicator, PMI, and rank indicator, RI.

2. The method of claim 1, further comprising:transmitting a layer- 1 reference signal received power, Ll-RSRP, measurement result to a serving cell of the UE.

3. The method of claim 1 or 2, wherein the configuration for early CSI acquisition comprises an indication of periodic or semi-periodic CSI-RS resources for the one or more LTM candidate cells to be measured.

4. The method of any of claims 1 to 3, further comprising:when CSI-RS resources indicated by the early CSI configuration exceed a predetermined limit, applying prioritization for the measurement.

5. The method of claim 4, wherein the prioritization is applied according to at least one of: prioritizing CSI-RS resources of the target cell over CSI-RS resources of other LTM candidate cells;prioritizing CSI-RS resources based on signal strength measurements;prioritizing CSI-RS resources based on cell priority information received from the serving cell; andprioritizing CSI-RS resources based on resource allocation timing.

6. The method of any of claims 1-5, further comprising:transmitting to the serving cell, information indicating its capability to support for the early CSI acquisition.

7. The method of claim 6, wherein the UE capability comprises information regarding a maximum number of CSI-RS resources and / or ports that the UE supports simultaneous measurement across all configured LTM candidate cells or per LTM Candidate cell.

8. The method of claim 6 or 7, wherein the UE capability comprises information regarding aP113067W001 40number of CSI processing units that the UE supports for the CSI-RS measurements including at least one of CRI, CQI, PMI, and RI.

9. The method of claim 4, wherein the predetermined limit is up to the UE’s capability to support for the early CSI acquisition.

10. A method performed by a network node providing a serving cell for a UE, comprising: transmitting a configuration for early CSI acquisition to the UE, the configuration comprising one or more LTM candidate cells;transmitting a command for LTM cell switch to a target cell to the UE, wherein the target cell is one of the one or more LTM candidate cells.

11. The method of claim 10, further comprising:receiving a layer-1 reference signal received power, Ll-RSRP, measurement result from the UE; anddetermining an LTM cell switch to the target cell for the UE.

12. The method of claim 10 or 11, wherein the configuration for early CSI acquisition comprises an indication of periodic or semi-periodic CSI-RS resources for the one or more LTM candidate cells to be measured.

13. The method of any of claims 10 to 12, wherein the configuration comprises prioritization information for CSI-RS resource measurements when CSI-RS resources indicated by the early CSI configuration exceed a predetermined limit.

14. The method of claim 13, wherein the prioritization information indicates at least one of: prioritizing CSI-RS resources of the target cell over CSI-RS resources of other LTM candidate cells;prioritizing CSI-RS resources based on signal strength measurements;prioritizing CSI-RS resources based on cell priority information; andprioritizing CSI-RS resources based on resource allocation timing.

15. The method of any of claims 10-14, further comprising:receiving from the UE, information indicating the UE's capability to support the early CSI acquisition.

16. The method of claim 15, wherein the UE capability comprises information regarding a maximum number of CSI-RS resources and / or ports that the UE supports for simultaneous measurement across all configured LTM candidate cells or per LTM candidate cell.

17. The method of claim 15 or 16, wherein the UE capability comprises information regarding a number of CSI processing units that the UE supports for the CSI-RS measurements including at least one of CRI, CQI, PMI, and RI.P113067W001 4118. A User Equipment (800), UE, configured to perform early CSI reporting, comprising: a communication interface (812) arranged for wireless communication,a processing circuitry (802), anda memory (810) including instructions which, when executed by said processing circuitry (802), cause said UE (800) to perform any of the claims 1 to 9.

19. A network node (900) configured for early CSI acquisition, comprising:a communication interface (906) arranged for wireless communication,a processing circuitry (902), anda memory (904) including instructions which, when executed by said processing circuitry (902), cause the network node to perform any of the claims 10 to 17.

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