Reception of LTM cell switch for a CLTM candidate cell

Abstract

Systems and methods related to a Layer 1 (L1) / Layer 2 (L2) Triggered Mobility (LTM) cell switch for a Conditional L1 / L2 Triggered Mobility (CLTM) candidate cell are disclosed. In one embodiment, a method performed by a User Equipment (UE) comprises receiving a configuration for a CLTM candidate cell, wherein the configuration includes a candidate cell configuration for the CLTM candidate cell, an associated CLTM execution condition, and a candidate cell identifier of the CLTM candidate cell. The method further comprises monitoring the CLTM execution condition and, while monitoring the CLTM execution condition, receiving from a network node an LTM Cell Switch command including the candidate cell identifier. The method further comprises, in response to the LTM Cell Switch command, performing an LTM Cell Switch to the CLTM candidate cell by applying the candidate cell configuration.

Description

3000-2702-P / Pl 13407US01 1RECEPTION OF LTM CELL SWITCH FOR A CLTM CANDIDATE CELLRELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Patent Application No.63 / 779,695, filed March 28, 2025, the disclosure of which is hereby incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] The present disclosure relates to a cellular communications network and, more specifically, to Layer 1 (Ll) / Layer 2 (L2) Triggered Mobility (LTM) cell switch and Conditional LTM (CLTM) cell switch in a cellular communications network.BACKGROUND

[0003] In a 3rdGeneration Partnership Project (3GPP) 5thGeneration (5G) system, Layer 1 (Ll) / Layer (2)-Triggered Mobility (LTM) is a procedure in which a next generation NodeB (gNB) receives LI measurement report(s) from a User Equipment (UE) and, on the basis of this LI measurement report(s), the gNB changes the UE’s serving cell by a cell switch command signaled via a Medium Access Control (MAC) Control Element (CE). The cell switch command indicates an LTM candidate configuration that the gNB previously prepared and provided to the UE through Radio Resource Control (RRC) signaling. Then, the UE switches to the target configuration according to the cell switch command. While it is not necessary for understanding the present disclosure, for more information, the interested reader is directed to 3GPP Technical Specification (TS) 38.300 (see, e.g., V18.0.0).

[0004] When configured by the network, it is possible to activate Transmission Configuration Indicator (TCI) states of one or multiple cells that are different from the current serving cell. This is sometimes called pre-activation of a candidate TCI state, since this is pre-activating a TCI state of an LTM candidate cell before the UE receives the LTM cell switch command i.e. before the LTM cell switch procedure. For instance, the TCI states of the LTM candidate cells can be activated in advance before any of those cells become the serving cell. This allows the UE to be downlink (DL) synchronized with those cells (or DL pre-sync), thereby facilitating a faster cell switch to one of those cells when cell switch is triggered.

[0005] Cell switch command is conveyed in a MAC CE, which contains the necessary information to perform the LTM cell switch. The overall procedure for LTM is shown in Figure3000-2702-P / Pl 13407US01 2

[0006] As illustrated in Figure 1, the steps of the procedure for LTM are as follows:

[0007] Step 1. The UE sends a MeasurementReport message to the gNB. The gNB decides to configure LTM and initiates LTM preparation.

[0008] Step 2. The gNB transmits an RRCReconfiguration message to the UE including the LTM candidate configurations.

[0009] Step 3. The UE stores the LTM candidate configurations and transmits an RRCReconfigurationComplete message to the gNB.

[0010] 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 CandidateTCLState 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 a Serving Cell, the UE indicates to lower layers the information regarding the Candidate Cell TCI States Activation / Deactivation MAC CE. Further details of this procedure can be found in 3GPP TS 38.321 (see, e.g., V18.0.0).

[0011] 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.

[0012] 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.

[0013] Step 7. The UE performs the random access procedure towards the target cell, if UE does not have valid TA of the target cell as specified in clause 6.1.3.xy of TS 38.321.

[0014] 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.

[0015] Conditional LTM (CLTM) is a procedure being specified in 3GPP Release 19. A UE may be configured with CLTM, which means the UE is configured with a CLTM candidate cell configuration (i.e. an RRCReconfiguration for the CLTM candidate cell) and an associated CLTM execution condition which is being monitored. When that CLTM execution condition is fulfilled, the UE executes CLTM i.e. by applying the RRC Reconfiguration associated to the CLTM3000-2702-P / Pl 13407US01 3candidate cell. For such a CLTM cell, the UE may have received a MAC CE from the network (e.g. from the serving cell) including a Timing Advance (TA) value for, before the CLTM execution, as agreed in RAN2#128:Agreements on C-LTM:I- [ . ]2. [...]3. [...]4. [...]5. [...]6. [...]7. [...]8. The Early TA is signalled to the LE from the source cell (i.e., not from the candidate cell directly to the LE). This agreement will be included in the LS to RAN1 / 3 / 4.9. The network can inform the candidate cell’s TA information to LE via new MAC CE, which is the TA value when LE switches to that candidate cell during CLTM.10. Candidate cell TA is maintained by a new timer.IL [...]SUMMARY

[0016] Systems and methods related to a Layer 1 (LI) / Layer 2 (L2) Triggered Mobility (LTM) cell switch for a Conditional L I / L2 Triggered Mobility (CLTM) candidate cell are disclosed. In one embodiment, a method performed by a User Equipment (LE) comprises receiving a configuration for a CLTM candidate cell, wherein the configuration includes a candidate cell configuration for the CLTM candidate cell, an associated CLTM execution condition, and a candidate cell identifier of the CLTM candidate cell. The method further comprises monitoring the CLTM execution condition and, while monitoring the CLTM execution condition, receiving from a network node an LTM Cell Switch command including the candidate cell identifier. The method further comprises, in response to the LTM Cell Switch command, performing an LTM Cell Switch to the CLTM candidate cell by applying the candidate cell configuration. In this manner, the network is enabled to efficiently be able to trigger a network-controlled mobility procedure for a LE configured with CLTM.3000-2702-P / Pl 13407US01 4

[0017] In one embodiment, the LTM Cell Switch command includes a Timing Advance (TA) value for the CLTM candidate cell indicated by the candidate cell identifier, and the UE receives the LTM Cell Switch command while the UE has a stored TA value for the same CLTM candidate cell with an associated TA timer running. In one embodiment, performing the LTM Cell Switch to the CLTM candidate cell comprises handling the TA value received in the LTM Cell Switch command by applying the received TA value and / or overriding a stored TA value for the same candidate cell. In one embodiment, performing the LTM Cell Switch to the CLTM candidate cell comprises performing the LTM Cell Switch to the CLTM candidate cell as a RACH-less procedure.

[0018] In one embodiment, the LTM Cell Switch command does not include a TA value for the CLTM candidate cell indicated by the candidate cell identifier, and the UE receives the LTM Cell Switch command while the UE has a stored TA value for the same CLTM candidate cell with an associated TA timer running. In one embodiment, performing the LTM Cell Switch to the CLTM candidate cell comprises applying the stored TA value for the same candidate cell. In one embodiment, performing the LTM Cell Switch to the CLTM candidate cell comprises performing the LTM Cell Switch to the CLTM candidate cell as a RACH-less procedure. In another embodiment, the UE releases the stored TA value for the same candidate cell. In one embodiment, the performing the LTM Cell Switch to the CLTM candidate cell comprises performing the LTM Cell Switch to the CLTM candidate cell as a RACH-based procedure.

[0019] In one embodiment, the method further comprises, upon receiving the LTM Cell Switch Command, handling an LTM candidate Timing Alignment Timer (LTM-TAT) associated with a validity of the stored TA value and associated with the CLTM candidate cell. In one embodiment, handling the LTM candidate Timing Alignment Timer (LTM-TAT) comprises stopping the LTM-TAT for the CLTM candidate cell indicated in the LTM Cell Switch command.

[0020] In one embodiment, the LTM Cell Switch command does not include a TA value for the CLTM candidate cell indicated by the candidate cell identifier, and the UE receives the LTM Cell Switch command while the UE has a stored TA value for the same CLTM candidate cell with an associated TA timer running, and where the UE receives, before or at the LTM cell switch procedure, an indication from a network node about whether the UE should apply the stored TA value or not. In one embodiment, the indication about whether the UE should apply the stored TA value or not is included within the LTM Cell Switch command. In another embodiment, the indication about whether the UE should apply the stored TA value or not is included with an associated CLTM or LTM configuration or in the configuration for the CLTM candidate cell. In one embodiment, the indication indicates that the UE should apply the stored TA value, and3000-2702-P / Pl 13407US01 5performing the LTM Cell Switch to the CLTM candidate cell comprises performing the LTM Cell Switch to the CLTM candidate cell as a Random Access Channel (RACH)-less procedure. In one embodiment, the indication indicates that the UE should not apply the stored TA value, and performing the LTM Cell Switch to the CLTM candidate cell comprises performing the LTM Cell Switch to the CLTM candidate cell as a RACH-based procedure.

[0021] In one embodiment, the LTM Cell Switch command comprises a TA value for the CLTM candidate cell, and the method further comprises determining whether to apply or not the TA value in the LTM Cell Switch command including the candidate cell identifier for the CLTM candidate cell, and whether or not to override a previously received TA value for the same candidate cell.

[0022] In one embodiment, the method further comprises receiving a TA value for the same CLTM candidate cell in a message other than the LTM Cell Switch command and storing the TA value. In one embodiment, receiving the TA value comprises receiving the TA value via a Medium Access Control (MAC) Control Element (CE), which is not the LTM Cell Switch command. In one embodiment, the MAC CE which includes the TA value is received by the UE before the LTM Cell Switch command. In another embodiment, the MAC CE which includes the TA value is received by the UE after the LTM Cell Switch command.

[0023] Corresponding embodiments of a UE are also disclosed. In one embodiment, a UE comprises a communication interface comprising a transmitter and a receiver. The UE further comprises processing circuitry associated with the communication interface. The processing circuitry is configured to cause the UE to receive a configuration for a CLTM candidate cell, wherein the configuration includes a candidate cell configuration for the CLTM candidate cell, an associated CLTM execution condition, and a candidate cell identifier of the CLTM candidate cell. The processing circuitry is further configured to cause the UE to monitor the CLTM execution condition and, while monitoring the CLTM execution condition, receive from a network node an LTM Cell Switch command including the candidate cell identifier. The processing circuitry is further configured to cause the UE to, in response to the LTM Cell Switch command, perform an LTM Cell Switch to the CLTM candidate cell by applying the candidate cell configuration.

[0024] Embodiments of a method performed by a network node are also disclosed. In one embodiment, a method performed by a network node comprises transmitting to a UE a configuration for a CLTM candidate cell, wherein the configuration includes a candidate cell configuration for the CLTM candidate cell, an associated CLTM execution condition, and a candidate cell identifier. The method further comprises transmitting to the UE an LTM Cell3000-2702-P / Pl 13407US01 6Switch command including the candidate cell identifier, for triggering an LTM to the CLTM candidate cell.

[0025] Corresponding embodiments of a network node are also disclosed. In one embodiment, a network node comprises processing circuitry configured to cause the network node to transmit to a UE a configuration for a CLTM candidate cell, wherein the configuration includes a candidate cell configuration for the CLTM candidate cell, an associated CLTM execution condition, and a candidate cell identifier. The processing circuitry is further configured to cause the network node to transmit to the UE an LTM Cell Switch command including the candidate cell identifier, for triggering an LTM to the CLTM candidate cell.BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the disclosure, and together with the description serve to explain the principles of the disclosure.

[0027] Figure 1 illustrates the steps of the Layer 1 (Ll) / Layer 2 (L2) Triggered Mobility (LTM) procedure in 3rdGeneration Partnership Project (3GPP) New Radio (NR).

[0028] Figure 2 illustrates a procedure for network-initiated LTM cell switch to a Conditional LTM (CTM) candidate cell, in accordance with an example embodiment present disclosure.

[0029] Figure 3 illustrates a further example embodiment, with steps in which the UE receives the LTM Cell Switch command including candidate cell identifier and the Timing Advance (TA) value while the UE has a stored TA value for the same candidate cell, in accordance with an example embodiment of the present disclosure.

[0030] Figure 4 shows an example of a communication system in accordance with some embodiments.

[0031] Figure 5 is another example of a communication system according to some embodiments.

[0032] Figure 6 shows a wireless device, which may be configured to operate in communication system of Figure 4 or in communication system of Figure 5.

[0033] Figure 7 shows a network node in accordance with some embodiments.

[0034] Figure 8 is a block diagram illustrating a virtualization environment in which functions implemented by some embodiments may be virtualized.

[0035] Figure 9 illustrates an LTM CandidateTiming Advance Command MAC CE in accordance with an exemplary implementation.3000-2702-P / Pl 13407US01 7DETAILED DESCRIPTION

[0036] 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.

[0037] 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.

[0038] There currently exist certain challenge(s). Conditional Layer (Ll) / Layer 2 (L2)-Triggered Mobility (CLTM) has advantages in terms of mobility robustness and lower interruption time. However, the User Equipment (UE) then has more control compared to the network in terms of mobility, since it is the UE which determines the timing to trigger the mobility procedure. If the network wanted to get control back using existing solutions, the network would need to first remove the CLTM candidate cell using Radio Resource Control (RRC) Reconfiguration and add the same cell as an LTM candidate cell. That would require a lot of signaling and a lot of the previous procedures performed for CLTM would be wasted e.g. Uplink (UL) pre-sync and / or Downlink (DL) pre-sync.

[0039] Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges. Systems and methods are disclosed herein in which a UE receives a configuration for a CLTM candidate cell (e.g. in an RRC Reconfiguration message), wherein the configuration includes a candidate cell configuration (for a CLTM candidate cell, or simply called ‘candidate cell’), an associated CLTM execution condition, and a candidate cell identifier. Further, while the UE is monitoring the CLTM execution condition, the UE receives from the network an LTM Cell Switch command including the candidate cell identifier, in response to which the UE performs an LTM Cell Switch to the candidate cell by applying the candidate cell configuration and changing to the candidate cell indicated by the candidate cell identifier. In other words, the UE receives the LTM Cell Switch command including the candidate cell identifier for a CLTM candidate cell and performs the LTM Cell Switch.

[0040] Figure 2 illustrates a procedure performed by a UE 200, a source network node 202, and a target network node 204, in accordance with an example embodiment present disclosure. As illustrated, the UE 200 receives, from the source network node 202, a configuration for a CLTM candidate cell, wherein this example, the configuration is received in an RRC Reconfiguration3000-2702-P / Pl 13407US01 8message (step 206). The RRC Reconfiguration message includes a candidate cell configuration for the CLTM candidate cell, an associated CLTM execution condition, and a candidate cell identifier. The UE 200 responds to the source network node 202 with an RRC Reconfiguration Complete message (step 208). The UE 200 monitors the CLTM execution condition (step 210). While the UE 210 is monitoring the CLTM execution condition, the UE 200 receives, from the source network node 202, an LTM Cell Switch command including the candidate cell identifier (step 212). In response to the LTM Cell Switch command including the candidate cell identifier received in step 212, the UE 200 performs the LTM Cell Switch to the candidate cell by applying the candidate cell configuration and changing to the candidate cell indicated by the candidate cell identifier (steps 214 and 216). A Random Access Channel (RACH) or RACH-less access may be performed to the candidate cell (i.e., to candidate cell operated by the target network node 204 in this example) in step 216. The UE 200 sends an RRC Reconfiguration Complete to the target network node 204 on the candidate cell (step 218).

[0041] In one embodiment, the LTM Cell Switch command (e.g., the LTM Cell Switch command of step 212) includes a Timing Advance (TA) value for the CLTM candidate cell indicated by the candidate cell identifier (referred to herein as a “received TA value”), received while the UE has a stored TA value (referred to herein as TA value*, or stored TA value*) for the same CLTM candidate cell. In other words, the TA value in the LTM Cell Switch command including the candidate cell identifier (i.e., the received TA value), for the CLTM candidate cell, is received while the UE has a stored TA value (i.e., a TA value* or stored TA value*) for the same CLTM candidate cell.

[0042] In another embodiment, the LTM Cell Switch command does not include a TA value for the CLTM candidate cell indicated by the candidate cell identifier (i.e., does not include a received TA value), while the UE has a stored TA value (i.e., a TA value* or stored TA value*) for the same CLTM candidate cell. In other words, the LTM Cell Switch command includes the candidate cell identifier but not a TA value for the CLTM candidate cell, but the UE has a stored TA value (i.e., a TA value*, or stored TA value*) for the same CLTM candidate cell.

[0043] In the description below, a set of actions that the UE performs related to the TA value and the stored TA value, for the same CLTM candidate cell, are disclosed.

[0044] Some exemplary embodiments of the present disclosure are as follows:

[0045] In a first embodiment, a method at a UE comprises:• Receiving a configuration for a CLTM candidate cell, wherein the configuration includes a candidate cell configuration (for a CLTM candidate cell, an associated CLTM execution condition, and a candidate cell identifier.3000-2702-P / Pl 13407US01 9• While monitoring the CLTM execution condition, receiving from a network node an LTM Cell Switch command including the candidate cell identifier,• In response to the LTM Cell Switch command performing an LTM Cell Switch to the CLTM candidate cell by applying the candidate cell configuration.

[0046] A second embodiment is the method of the first embodiment, wherein the LTM Cell Switch command includes a TA value for the CLTM candidate cell indicated by the candidate cell identifier (denoted received TA value), received while the UE has a stored TA value (denoted TA value*, or stored TA value*) for that same CLTM candidate cell with an associated TA* timer running.

[0047] A third embodiment is the method of the first embodiment, wherein the LTM Cell Switch command does not include a TA value for the CLTM candidate cell indicated by the candidate cell identifier, while the UE has a stored TA value (denoted TA value*, or stored TA value*) for that same CLTM candidate cell with an associated TA* timer running.

[0048] A fourth embodiment is the method of the first embodiment, wherein the LTM Cell Switch command does not include a TA value for the CLTM candidate cell indicated by the candidate cell identifier, while the UE has a stored TA value (denoted TA value*, or stored TA value*) for that same CLTM candidate cell with an associated TA* timer running, and where the UE receives, before or at the LTM cell switch procedure, an indication from the network about whether the UE should apply the stored TA value* or not.

[0049] A fifth embodiment is the method of the fourth embodiment, wherein the indication about whether the UE should apply the stored TA value* or not, is included within the LTM Cell Switch command.

[0050] A sixth embodiment is the method of the fourth embodiment, wherein the indication about whether the UE should apply the stored TA value* or not, is included with the (C)LTM configuration, e.g. in LTM-Config, or in the LTM candidate configuration for the CLTM candidate cell, e.g. within the corresponding LTM-Candidate.

[0051] A seventh embodiment is the method of the fourth, fifth, or sixth embodiment, wherein the UE performs the LTM Cell Switch to the CLTM candidate cell as a RACH-less procedure, if so indicated by the indication, and wherein the UE otherwise performs the LTM Cell Switch to the CLTM candidate cell as a RACH-based procedure.

[0052] An eighth embodiment is the method of the second embodiments, further comprising handling the TA value received in the LTM Cell Switch command by applying the received TA value and / or overriding the stored TA value* for that same candidate cell.3000-2702-P / Pl 13407US01 10

[0053] A ninth embodiment is the third embodiment, further comprising applying the stored TA* value for that same candidate cell, even if the LTM Cell Switch command does not include a TA value.

[0054] A tenth embodiment is the method of the third embodiment, further comprising releasing the stored TA* value forthat same candidate cell, in case the LTM Cell Switch command does not include a TA value.

[0055] A eleventh embodiment is the method of the tenth embodiment, wherein the UE performs the LTM Cell Switch to the CLTM candidate cell as a RACH-based procedure.

[0056] A twelfth embodiment is the method of any of the first second, third, eighth, ninth, and tenth embodiments, wherein upon receiving the LTM Cell Switch Command, handling an LTM candidate Timing Alignment Timer (LTM-TAT) associated with a validity of the stored TA value*, and associated with the CLTM candidate cell.

[0057] A thirteenth embodiment is the method of the twelfth embodiment, wherein handling the LTM candidate Timing Alignment Timer (LTM-TAT) comprises stopping the LTM-TAT for the CLTM candidate cell indicated in the LTM CS command.

[0058] A fourteenth embodiment is the method of any of the preceding embodiments, further comprising determining whether to apply or not the TA value in the LTM Cell Switch command including the candidate cell identifier for the CLTM candidate cell, and whether or not to override the previously received TA value for that same candidate cell (stored TA value*).

[0059] A fifteenth embodiment is the method of any of the preceding embodiments, wherein the stored TA value* (or denoted TA value*) is received by the UE via a Medium Access Control (MAC) Control Element (CE) which is not the LTM Cell Switch command.

[0060] In one option, the MAC CE which includes the stored TA value* is received by the UE before an LTM Cell Switch command

[0061] In one option, the MAC CE which includes the stored TA value* is received by the UE after an LTM Cell Switch command

[0062] In a sixteenth embodiment, a method at a network node comprises:• transmitting to a UE a configuration for a CLTM candidate cell, wherein the configuration includes a candidate cell configuration (for a CLTM candidate cell, an associated CLTM execution condition, and a candidate cell identifier.• transmitting to the UE an LTM Cell Switch command including the candidate cell identifier, for triggering an LTM to the CLTM candidate cell.

[0063] A seventeenth embodiment is the method of the sixteenth embodiment, wherein the LTM Cell Switch command includes a TA value for the CLTM candidate cell indicated by the3000-2702-P / Pl 13407US01 11candidate cell identifier (denoted received TA value), received while the UE has a stored TA value (denoted TA value*, or stored TA value*) for that same CLTM candidate cell.

[0064] An eighteenth embodiment is the method of the sixteenth embodiment, wherein the LTM Cell Switch command does not include a TA value for the CLTM candidate cell indicated by the candidate cell identifier, while the UE has a stored TA value (denoted TA value*, or stored TA value*) for that same CLTM candidate cell.

[0065] Certain embodiments may provide one or more of the following technical advantage(s). Embodiments of the present disclosure may enable the network to efficiently be able to trigger a network-controlled mobility procedure for a UE configured with CLTM. Efficiently in this context means, e.g., that there is no ambiguity between the UE and the network when it comes the TA value to be used and validity of it e.g. handling of the LTM-Time Alignment Timer (TAT).

[0066] The teachings of certain embodiments may improve, e.g., data rate, latency, and / or power consumption.

[0067] The present disclosure describes a UE configured with mobility procedure. The mobility procedure may correspond to a lower layer mobility, such as LTM and / or Conditional LTM.

[0068] The present disclosure refers to the term “L1 / L2 based inter-cell mobility” as used in the 3GPP Release 18 Work Item Description in 3GPP, though it interchangeably also uses the terms L1 / L2 mobility, Ll-mobility, LI based mobility, Ll / L2-centric inter-cell mobility, L1 / L2 inter-cell 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 its 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, which may be referred as a L1 / L2 inter-cell mobility execution command or LTM cell switch command. The change of serving cell (e.g. change of PCell) may also lead to a change in 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.3000-2702-P / Pl 13407US01 12

[0069] In some embodiments of the solution(s) described herein, a Timing Advance (TA) value is acquired for the UE in a neighboring / target cell so that the UE can avoid transmission of a Physical Random Access Channel (PRACH) preamble (and reception of a corresponding Random Access Response, RAR, message) during the access to that target cell. The acquisition thus enables the UE to perform a RACH-less access to the target cell during the handover procedure (where at least the PRACH preamble and the RAR can be skipped compared to the normal RACH procedure that is performed during a normal handover / Reconfiguration With Sync procedure).

[0070] A TA acquisition configuration may include information needed by the network nodes and / or the UE to perform a TA acquisition procedure, such as an indication of which method to use for TA acquisition, one or multiple RACH configuration(s), or one or multiple preamble index(s) used at UE transmission of random access (RA) preambles, or one or multiple RA-Radio Network Temporary Identities (RNTI(s)). A TA acquisition configuration may be provided to the UE per neighbor cell, e.g. per LTM candidate cell.

[0071] The text describes Conditional LTM (CLTM), which can be viewed as a form of conditional reconfiguration. In CLTM, the UE is configured with at least one 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 as CLTM execution condition. The evaluation of CLTM execution condition associated to a CLTM candidate cell is performed by the assessment of lower layer measurements, such as Layer 1 reference signal received power (LI -Reference Signal Received Power (RSRP)) and / or Synchronization Signal (SS)-RSRP, derived from SS / Physical Broadcast Channel (PBSCH) Blocks (SSBs) and / or Channel State Information (CSI) Reference Signals (CSL RSs) of either the source cell and / or an LTM candidate cell. Lower layer measurements, in this context, are measurements reported to support lower layer procedures like beam management, candidate cell TCI state activation / deactivation, early timing advance (TA) acquisition, and link adaptation, and they are not filtered based on Layer 3 (L3) parameters, though there may or may not be some filtering of these measurements based on the other 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 identified s), offset(s), threshold(s), reference signal (RS) type, trigger quantity such as RSRP, reference signal received quality (RSRQ) or signal-to-interference-plus-noise ratio (SINR), time-to-trigger (TTT), and so forth.

[0072] In the context of CLTM, the UE relies on evaluating one or two condition(s), referred to as CLTM execution condition(s), LTM execution condition(s), or triggering condition(s), or a3000-2702-P / Pl 13407US01 13combination thereof. And, when the condition(s) for a CLTM candidate cell is fulfilled, the UE performs a cell switch, which may be seen as a kind of LTM execution which is not triggered by the reception of an LTM cell switch command; this may also be considered as a kind of LTM cell switch, or LTM cell switch execution, or Conditional LTM cell switch, or Conditional LTM execution, or CLTM execution, or simply cell switch. According to the methods outlined in the present disclosure, upon satisfaction of the execution condition(s), the UE initiates an LTM cell switch. The term LTM cell switch refers to the process of a UE changing its cell from a source cell to a target cell, using L1 / L2 triggered mobility (LTM). In the context of Conditional LTM execution, the text may refer to the serving cell before the LTM cell switch as source cell, old source cell, or previous source cell.

[0073] The text also describes an LTM candidate cell within the framework of Conditional LTM. The candidate cell may be referred to as a CLTM candidate cell, CLTM cell, simply candidate cell, candidate target cell, simply target cell, LTM candidate cell, LTM cell, or L1 / L2 inter-cell mobility candidate cell, depending on the context or terminology used in the present disclosure. Essentially, it denotes a cell to which the UE is directed or switches to in the event of executing a conditional L1 / L2 inter-cell mobility procedure after meeting the associated execution condition(s) and may also be termed as new source cell or next source cell after the LTM cell switch. These cells may also be termed as candidate cells, mobility candidates, non-serving cells, additional cells, candidate target cell, simply target cell or deactivated cells. An LTM candidate cell might also pertain to a candidate cell in a 5G Radio Access Technology like New Radio (NR) or a future 6G Radio Access Technology.

[0074] In an embodiment of solution(s) described herein, the UE receives an LTM candidate cell configuration for Conditional LTM, typically through an RRC Reconfiguration message, which is stored in the UE and applied upon fulfillment of the associated CLTM execution conditions. An LTM candidate cell configuration comprises the configuration which the UE needs to start to operate accordingly when it performs a Conditional LTM execution to that LTM candidate cell e.g., upon the fulfilment of CLTM execution conditions. A candidate cell configuration may include parameters in the information element (IE) CellGroupConfig per LTM candidate cell and / or an embedded RRC Reconfiguration per candidate cell. 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 performing the early uplink (UL) or downlink (DL) synchronization with that LTM cell. This identifier is sometimes known as the LTM candidate cell configuration identifier (ID) or LTM candidate configuration index (or similar).3000-2702-P / Pl 13407US01 14

[0075] As illustrated in Figure 2, in one embodiment of the present disclosure, the UE 200 receives a configuration for a CLTM candidate cell (e.g. in an RRC Reconfiguration message, or in an RRC Resume message) (step 206). The configuration includes a candidate cell configuration (for a CLTM candidate cell, or simply called ‘candidate cell’), an associated CLTM execution condition, and a candidate cell identifier. And, while the UE is monitoring the CLTM execution condition (step 210), the UE receives from the network an LTM Cell Switch command including the candidate cell identifier (step 212), in response to which the UE performs an LTM Cell Switch to the candidate cell by applying the candidate cell identifier (step 214). In other words, the UE receives the LTM Cell Switch command including the candidate cell identifier for a CLTM candidate cell and performs the LTM Cell Switch.

[0076] In one option, the configuration for a CLTM candidate cell may be received in an Information Element (IE) LTM-Config. Within the LTM-Config IE, the candidate cell is configured, and that is an CLTM candidate cell (i.e. configured for CLTM) when a CLTM execution is associated to that CLTM candidate in the LTM-Config IE. For example, if a candidate cell has a candidate cell identifier set to X, and the LTM-Config includes CLTM execution conditions (e.g. cltm-ServingCellExecutionConditions) and at least one of the conditions is associated to that candidate cell identifier, the candidate cell identifier is a CLTM candidate cell.

[0077] In one option, the configuration for a CLTM candidate cell (or candidate cell configuration) may correspond to an RRCReconfiguration, received in a container for the CLTM candidate cell e.g. an RRCReconfiguration within the IE LTM-Candidate.

[0078] In one option, the LTM Cell Switch Command corresponds to a lower layer signaling e.g. a MAC Control Element, such as the ‘LTM Cell Switch Command’ as specified in 3GPP Technical Specification (TS) 38.321, Rel-18 version.

[0079] In one option, the LTM Cell Switch Command corresponds to a light weight RRC signaling e.g. an RRC signaling with a limited number of parameters and / or fields and / or information elements.

[0080] In one option, the candidate cell identifier may correspond to the LTM-Candidateld-r 18, included in the IE LTM-Candidate, for the CLTM candidate cell and referred later in the LTM Cell Switch Command (possibly with another field name e.g. ‘the Target Configuration ID’).

[0081] In a set of embodiments, the LTM Cell Switch command received by the UE in step 212 includes a TA value for the CLTM candidate cell indicated by the candidate cell identifier (referred to herein as a received TA value), received while the UE has a stored TA value (referred to herein as a TA value*, or stored TA value*) for that same CLTM candidate cell. In other words, the TA value in the LTM Cell Switch command including the candidate cell identifier (i.e., a3000-2702-P / Pl 13407US01 15received TA value), for the CLTM candidate cell, is received while the UE has a stored TA value (i.e., a TA value*, or stored TA value*) for that same CLTM candidate cell. In one embodiment, the UE receives the stored TA value* for the CLTM candidate cell in a message (e.g. lower layer message, such as a MAC CE), which also indicates the candidate cell identifier of the CLTM candidate cell. That message is received after the UE transmits a preamble to the CLTM candidate cell (e.g. in response to a PDCCH order for triggering TA acquisition / early Uplink (UL) sync, indicating the candidate cell identifier of the CLTM candidate cell). In one sub-option, the UE receives the stored TA value* in an ‘LTM Candidate Timing Advance Command MAC CE’, received before the UE receives the LTM Cell Switch command and while the UE is monitoring the CLTM execution conditions.

[0082] Figure 3 illustrates a further example embodiment, with steps in which the UE 200 receives the LTM Cell Switch command including candidate cell identifier and the TA value while the UE has a stored TA value* for the same candidate cell. The steps of the procedure of Figure 3 are as follows. The UE 200 receives, from the source network node 202, a configuration for a CLTM candidate cell, wherein this example, the configuration is received in an RRC Reconfiguration message (step 300). The RRC Reconfiguration message includes a candidate cell configuration for the CLTM candidate cell, an associated CLTM execution condition and a candidate cell identifier. The UE 200 responds to the source network node 202 with an RRC Reconfiguration Complete message (step 302). The UE 200 monitors the CLTM execution condition (step 304). Steps 300, 302, and 304 correspond to step 206, 208, and 210 of Figure 2. While the UE 210 is monitoring the CLTM execution condition, the UE 200 receives, from the source network node 202, a PDDCH order triggering TA acquisition or early synchronization for the candidate cell (i.e., the PDCCH order includes the candidate cell identifier) (step 306). In response thereto, the UE 200 performs TA acquisition or early UL synchronization to the candidate cell by transmitting a Random Access Preamble to the candidate cell corresponding to the candidate cell identifier (step 308) and receiving an LTM Candidate Timing Advance Command MAC CE including the candidate cell identifier an TA value* (step 310). The UE 200 stores the TA value* for the candidate cell. Sometime thereafter, the UE 200 receives, from the source network node 202, an LTM Cell Switch command including the candidate cell identifier, a received TA value, and a TCI state ID (step 312). Step 312 corresponds to step 212 of Figure 2. In response to the LTM Cell Switch command including the candidate cell identifier received in step 312, the UE 200 performs the LTM Cell Switch to the candidate cell by applying the candidate cell configuration, applying the received TA value for the candidate cell where the received TA value overrides the stored TA value* for the candidate cell, and changing to the candidate cell3000-2702-P / Pl 13407US01 16indicated by the candidate cell identifier (steps 314 and 316). A RACH or RACH-less access may be performed to the candidate cell (i.e., to candidate cell operated by the target network node 204 in this example) in step 316. The UE 200 sends an RRC Reconfiguration Complete to the target network node 204 on the candidate cell (step 318).

[0083] In a set of embodiments, in contrast to the example illustrated in Figure 3, the LTM Cell Switch command received by the UE 200 in step 312 does not include a TA value for the CLTM candidate cell indicated by the candidate cell identifier, while the UE has a stored TA value (i.e., the TA value*, or stored TA value*) for that same CLTM candidate cell. This stored TA value* may be the TA value previously received in step 310 due to the triggered TA acquisition or early synchronization to the candidate cell. In other words, the LTM Cell Switch command of step 312 includes the candidate cell identifier without any TA value for the CLTM candidate cell, while the UE has a stored TA value (denoted TA value*, or stored TA value*) for that same CLTM candidate cell. In one embodiment, when the UE 200 receives the LTM Cell Switch command, the UE 200 determines if the stored TA value* is still valid, meaning that the UE 200 will check if the associated time alignment timer for the stored TA* value is still running. In one sub-option, the UE 200 receives the stored TA value* in an ‘LTM Candidate Timing Advance Command MAC CE’, received before the UE 200 receives the LTM CS command and while the UE 200 is monitoring the CLTM execution conditions. In another sub-option, the UE 200 estimates the store TA value* by itself (with the so called UE-based TA measurements) before the reception of the LTM CS command and while the UE 200 is monitoring the CLTM execution conditions.

[0084] Now, a description is provided of embodiments related to handling of the stored TA value* and received TA value for the same candidate cell.

[0085] In a set of embodiments, the UE 200 handles the TA value received in the LTM Cell Switch command in step 312 including the candidate cell identifier (denoted received TA value) by applying the received TA value and overriding a previously received TA value (i.e., the TA value*, or stored TA value*) for that same candidate cell, which may comprise one or more (and / or a combination of) of the following actions:• Using the received TA value for Uplink transmissions with the candidate cell e.g. to send a scheduling request on Physical Uplink Control Channel (PUCCH) and / or to transmit payload on Physical Uplink Shared Channel (PUSCH); The UE overrides the previously received TA value (denoted TA value*) i.e. it ignores and / or deletes it, regardless of whether that TA value* is the same as TA value or not.3000-2702-P / Pl 13407US01 17• Processing a received Timing Advance Command in which the received TA value is included. In other words, the LTM Cell Switch Command includes the Timing Advance Command, which is what the UE processes.• Processing the Timing Advance Command for the CLTM candidate cell when the Timing Advance Command is not set to a value indicating the need for a random access e.g. not set to an ‘FFF’ value.• Applying the received TA value and overriding the stored TA value* when the Timing Advance Command received in the LTM Cell Switch command is not set to a value indicating the need for a random access e.g. not set to an ‘FFF’ value. In other words, when the LTM Cell Switch command indicates the UE to access the candidate cell via RACH- less (i.e. without a random access procedure during execution) the UE applies the received TA value.• Deleting (releasing, discarding, ignoring) the stored TA value*. In one sub-option, deleting (releasing, discarding) the stored TA value* only when the Timing Advance Command received in the LTM Cell Switch command is not set to a value indicating the need for a random access e.g. not set to an ‘FFF’ value. In other words, when the LTM Cell Switch command indicates the UE to access the candidate cell via RACH-less (i.e. without a random access procedure during execution) the UE deletes the stored TA value*.• When the LTM Cell Switch Command is received and the Timing Advance Command (within the LTM Cell Switch Command) is not set to ‘FFF1, the UE applies the Timing Advance Command for the Primary Timing Alignment Group (PTAG), for the CLTM candidate cell, deletes the stored TA value*, and starts (or re-starts the time alignment timer associated to the PTAG).

[0086] In regarding to handling of LTM-TAT e.g. for the CLTM candidate cell for which the UE received the LTM CS command, in a set of embodiments, the UE 200 handles an LTM candidate Timing Alignment Timer (LTM-TAT), e.g., Ttm-Candidate-TimeAlignmentTimer’, associated with the validity of the previously received TA value*. The handling the LTM-TAT may comprise one or more of the following:• In one option the UE stops (if running) the LTM-TAT for the previously received TA value (TA value*) for the CLTM candidate cell indicated by the candidate cell identifier in the LTM Cell Switch Command. The benefit is that the UE would not need to monitor the validity of the TA value* previously received for CLTM, since the UE is applying the received TA value in the LTM CS command. Stopping the LTM-TAT, for the candidate3000-2702-P / Pl 13407US01 18cell the UE is going to via LTM CS, also prevents such timer to expiry, which would lead to assumptions of the validity of the TA which are not necessarily accurate.• In one option the UE keeps running (if not stopped) the LTM-TAT for the previously received TA value for the CLTM candidate cell indicated by the candidate cell identifier in the LTM Cell Switch Command, and the validity of the received TA value in the LTM CS command is controlled by that timer.• In one option the UE stops (if running) the LTM-TAT for the previously received TA value (TA value*) for the CLTM candidate cell indicated by the candidate cell identifier in the LTM Cell Switch Command (e.g. stops Ttm-Candidate-TimeAlignmentTimer’) and starts (or re-starts) a second time alignment timer (TAT), e.g., ‘timeAlignmentTimer’ associated with the Primary Time Alignment Group (PTAG), wherein the second TAT which is the timer to be used for a new serving cell (not an LTM candidate cell) after the LTM Cell Switch. Notice that the cell is the same cell which was a candidate cell and became the new serving cell after the LTM Cell Switch.o In one sub-option the second time alignment timer is started with the value of the remaining time for expiry of the LTM-TAT for the candidate cell which became the new serving cell after the LTM Cell Switch.o In one sub-option the second time alignment timer is started with a value configured with an RRC message, as part of the CLTM candidate cell configuration.• In one option the UE stops (if running) the LTM-TAT for the previously received TA value (TA value*) for the CLTM candidate cell indicated by the candidate cell identifier in the LTM Cell Switch Command, and the UE keeps running (if not stopped) the LTM-TAT for one or more previously received TA value(s) (stored TA values*) for other CLTM candidate cell(s) which are not the ones indicated by the candidate cell identifier in the LTM Cell Switch Command.

[0087] In a dependent embodiment, the TA value in the LTM Cell Switch command including the candidate cell identifier (denoted received TA value), for a CLTM candidate cell, is received while the UE 200 has a stored TA value (denoted TA value*, or stored TA value*) for that same CLTM candidate cell, wherein the UE performs one or more actions in response to the LTM Cell Switch Command based on the LTM candidate Timing Alignment Timer (LTM-TAT), e.g., Ttm-Candidate-TimeAlignmentTimer’, associated with the validity of the previously received TA value*. In one option, when the LTM-TAT is running for a CLTM candidate cell and the UE receives the LTM CS command for that CLTM candidate cell, the UE considers the received TA value as valid and applies it during the LTM cell switch for the CLTM candidate cell.3000-2702-P / Pl 13407US01 19

[0088] In regard to determining to apply or not the received TA value for the same candidate cell, in a dependent step, the UE 200 determines whether to apply or not the TA value in the LTM Cell Switch command including the candidate cell identifier (denoted received TA value), for the CLTM candidate cell, and whether or not to override the previously received TA value for that same candidate cell (stored TA value*).• In one option, the UE applies the received TA value and overrides the stored TA value* when the Timing Advance Command received in the LTM Cell Switch command is not set to a value indicating the need for a random access e.g. not set to an ‘FFF’ value. In other words, when the LTM CS command indicates the UE to access the candidate cell via RACH-less (i.e. without a random access procedure during execution) the UE applies the received TA value.• In one option, the UE does NOT apply the received TA value and does NOT override the stored TA value* when the Timing Advance Command received in the LTM Cell Switch command is set to a value indicating the need for a random access e.g. set to an ‘FFF’ value. In other words, when the LTM CS command indicates the UE to access the candidate cell via RACH (i.e. with a random access procedure during execution) the UE does NOT apply the received TA value and instead uses the stored TA value and performs a RACH- less procedure for the LTM Cell Switch to the CLTM candidate cell.o In one sub-option, in addition to the condition above, RACH-less is performed when the LTM-TAT is also running when the UE receives the LTM CS command.• In one option, the UE applies the received TA value when for the same CLTM candidate cell the UE does NOT have a stored TA value available, or the associated LTM-TAT • In one option, the UE DOES not apply the received TA value when for the same CLTM candidate cell the UE has a stored TA value available, or the associated LTM-TATo In one sub-option, in addition to the condition above, RACH-less is performed when the LTM-TAT is also running when the UE receives the LTM CS command.

[0089] In a dependent step, while the UE has a stored TA value (denoted TA value*, or stored TA value*) for the CLTM candidate cell, the UE receives an LTM Cell Switch command including the candidate cell identifier within any TA value for the included candidate cell identifier and determines whether the LTM Cell Switch command also includes a TA value associated to the CLTM candidate cell. Notice that in this option, the LTM CS command has no TA value because the TA value is an optional field, or there is a particular value (e.g., ‘FFF’) for the TA which indicates that the TA value should be ignored by the UE (the particular value of the TA is clearly specified and reserved).3000-2702-P / Pl 13407US01 20• In one option, when the UE determines that the LTM Cell Switch command including the candidate cell identifier also includes the TA value, the UE applies the received TA value and ignores / discards / overrides the stored TA value*.o In one sub-option, in that case the UE performs a RACH-less procedure during the LTM Cell Switch.• In one option, when the UE determines that the LTM Cell Switch command including the candidate cell identifier also includes the TA value, and that TA value is not set to a value indicating that random access is to be performed (i.e. not set to ‘FFF’), the UE applies the received TA value and ignores / discards / overrides the stored TA value*.o In one sub-option, in that case the UE performs a RACH-less procedure during the LTM Cell Switch.• In one option, when the UE determines that the LTM Cell Switch command including the candidate cell identifier does NOT include the TA value, the UE applies the stored TA value* for the CLTM candidate when it performs the LTM cell switch.o In one sub-option, in that case the UE performs a RACH-less procedure during the LTM Cell Switch.o In one sub-option, in that case the UE performs a RACH-less procedure during the LTM Cell Switch only when the LTM-TAT is running for the CLTM candidate cell indicated by the candidate cell identifier.o In one sub-option, the UE applies the stored TA value* only if the associated timer alignment timer for the stored TA value* is still running.o In one sub-option, the UE applies the stored TA value* only if the LTM Cell Switch command including the candidate cell identifier is received within a time from when the store TA value* was previously received.o In one sub-option, the UE applies the stored TA value* only if the UE has a TCI state activated for the candidate cell identifier received within the LTM Cell Switch command• In one option, when the UE determines that the LTM Cell Switch command including the candidate cell identifier does NOT include the TA value, the UE releases also the stored TA value* for the CLTM candidate when it performs the LTM cell switch.o In this option the UE releases also the stored TA value* and this means that when execution the LTM cell switch procedure to the candidate cell associated to the candidate cell identifier received within the LTM Cell Switch command, the UE performs the random access procedure.3000-2702-P / Pl 13407US01 21• In one option, when the UE determines that the LTM Cell Switch command including the candidate cell identifier does NOT include the TA value, the UE applies the stored TA value* for the CLTM candidate when it performs the LTM cell switch if there is an explicit indication received within the LTM Cell Switch command.o In this case, the received LTM Cell Switch command will have an explicit indication which indicates to the UE whether to apply the stored TA or not.

[0090] In one example, the method may be captured in the 3GPP TS 38.321 specifications as follows:5.2 Maintenance of Uplink Time AlignmentRRC configures the following parameters for the maintenance of UL time alignment:[...]- Itm-Candidate-TimeAlignmentTimer which controls how long the MAC entity considers the CLTM candidate cells associated with this timer to be uplink time aligned. Each Itm-Candidate-TimeAlignmentTimer is associated with one candidate configuration for CLTM. This timer is stopped when the UE receives a LTM Cell Switch Command.[...]The MAC entity shall:[...]1> when a conditional LTM cell switch procedure is triggered for a LTM candidate cell as in clause 5.y.3 or indicated by upper layer, and the Itm-Candidate-TimeAlignmentTimer associated with the LTM candidate cell is running:2> apply the stored TA value associated with the LTM target cell for the PTAG as specified in clause 6.1.3.4x;2> start or restart the timeAlignmentTimer associated with the PTAG.[...]Editor’s NOTE: The above description is based on the same logic as R18 LTM. While for CLTM, it is open when to use the TA value provided in MAC CE and whether / when to use the UE-based TA.[...]5.2x Maintenance of UL Synchronization for LTM candidate cell The MAC entity shall for each LTM candidate cell:1> when a LTM Candidate Timing Advance Command MAC CE described in clause 6.1.3.4x is received: 2> store the TA value in the Timing Advance Command MAC CE for the indicated LTM candidate cell; 2> start or restart the Itm-Candidate-TimeAlignmentTimer associated with the indicated LTM candidate cell.3000-2702-P / Pl 13407US01 22Editor’s NOTE: Whether the new MAC CE “LTM Candidate Timing Advance Command MAC CE” from the source cell indicates the LTM candidate cell or TAG is FFS.[ •]6.1.3.4x LTM Candidate Timing Advance Command MAC CEThe LTM Candidate Timing Advance Command MAC CE is identified by MAC subheader with eLCID as specified in Table 6.2.1-lb.It has a fixed size and consists of two octets defined as follows (Figure 6.1.3.4x-l):Editor’s NOTE: The detailed field(s) and corresponding description will be further updated based on the discussion progress.- Candidate Config ID: This field indicates the corresponding candidate configuration ID associated with this Timing Advance Command. The length of the Candidate Config ID field is X bits;- Timing Advance Command: This field indicates the index value TA(0, 1, 2... 63) used to control the amount of timing adjustment that MAC entity has to apply (as specified in TS 38.213 [6]) when UE switches to the candidate cell during CLTM, where the CLTM candidate cell is indicated by the latest PDCCH order before UE receives this MAC CE. The length of the field is 12 bits;- TL If two TAGs are configured for the CLTM candidate cell indicated by the latest PDCCH order before UE receives this MAC CE, this field indicates one of the two TAGs to which the Timing Advance Command is applied. The field set to 0 indicates the tag2-Id and the field set to 1 indicates the tag-id of the CLTM candidate cell;Editor’s NOTE: Whether conditional intra-CU LTM could co-exist with MIMO 2TA is FFS, this part could be updated after more progress.- R: Reserved bit, set to 0.Editor’s NOTE: The following figure just provides the rough example for the LTM Candidate Timing Advance Command MAC CE, where the details will be further updated based on RAN2 progress. It is not expected too much comments on this format.[REPRODUCED AS FIGURE 9]Figure 6.1.3.4x-1: LTM CandidateTiming Advance Command MAC CE [TBD example]5.18.35 LTM Cell Switch CommandEditor’s NOTE: Whether / How to differentiate legacy intra-CU LTM and R19 inter-CU LTM (depending on the progress on security part for inter-CU LTM in RAN2 / SA3) needs further discussion. Current agreement for inter-CU LTM CSC is: R18 LTM CSC MAC CE is baseline to trigger LTM cell switch for inter-CU LTM. Re-use legacy LTM Cell Switch Command MAC CE for inter-SN LTM. SA3 has reached a compromise that the NCC can be transmitted to the UE in plaintext via MAC CE message. But further RAN2 progress on the details is needed.The network may instruct the UE to perform LTM cell switch procedure by sending the LTM Cell Switch Command MAC CE described in clause 6.1.3.75.The MAC entity shall:1> if the MAC entity receives an LTM Cell Switch Command MAC CE on a Serving Cell:2> indicate to upper layers that the LTM cell switch procedure is triggered and the Target Configuration ID included in the LTM Cell Switch Command MAC CE;2> if the MAC reset operation as specified in clause 5.12 is performed, as requested by upper layers:3000-2702-P / Pl 13407US01 232> stop the Itm-Candidate-TimeAlisnmentTimer associated with the indicated LTM candidate cell.3> if Timing Advance Command value (hexa-decimal) is not set as FFF:4> process the received Timing Advance Command (see clause 5.2);4> consider the RACH-less LTM cell switch to be ongoing;4> if the MAC entity is associated with SCG:5> indicate to upper layers to skip the Random Access procedure for this LTM cell switch.3> else if the UE is configured with UE-based Timing Advance measurement as specified in TS 38.331[5] and the UE has successfully measured the Timing Advance for the SpCell of the indicated LTM target configuration:4> process the measured Timing Advance (see clause 5.2);4> consider the RACH-less LTM cell switch to be ongoing.4> if the MAC entity is associated with SCG:5> indicate to upper layers to skip the Random Access procedure for this LTM cell switch.3> consider the SSB associated to the TCI state indicated by TCI state ID field as the one used for configured uplink grant selection for the initial uplink transmission towards the candidate cell for RACH-less LTM cell switch (as in clause 5.8.2);3> indicate to lower layers the information regarding the TCI state information included in the LTM Cell Switch Command MAC CE.

[0091] Figure 4 shows an example of a communication system 400 in accordance with some embodiments.

[0092] In the example, the communication system 400 includes a telecommunications network 402 that includes an access network 404, such as a radio access network (RAN), and a core network 406, which includes one or more core network nodes 408. The access network 404 includes one or more access network nodes or base stations of various types, access network nodes 410A and 410B are depicted (which may be collectively referred to as network nodes 10), or any other similar 3rdGeneration Partnership Project (3GPP) access nodes or non-3GPP access points (APs). Some embodiments of the access network 404 may include more than one access network technology. The network nodes 410 of access network 404 facilitate direct or indirect connection of wireless devices, also referred to as user equipments (UEs), such as by connecting UEs 412A, 412B, 412C, and 412D (one or more of which may be generally referred to as UEs 412) to the core network 406 over one or more wireless connections.

[0093] 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 402 includes one or more Open-3000-2702-P / Pl 13407US01 24RAN (ORAN) network nodes. An ORAN network node is a network node in the telecommunications network 402 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 402, including one or more access network nodes 410 and / or core network nodes 408.

[0094] Examples of an ORAN network node include an open radio unit (O-RU), an open distributed unit (O-DU), an open central unit (O-CU), including an O-CU control plane (O-CU-CP) or an O-CU user plane (O-CU-UP), a RAN intelligent controller (near-real time or non-real time) hosting software or software plug-ins, such as a near-real time control application (e.g., xApp) or a non-real time control application (e.g., rApp), or any combination thereof (the adjective “open” designating support of an ORAN specification). An ORAN network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an Al, Fl, Wl, El, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN network node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an O-2 interface defined by the O-RAN Alliance or comparable technologies.

[0095] The network nodes 410 facilitate direct or indirect connection of one or more UEs 412 to the core network 406 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 400 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 400 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0096] The UEs 412 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 410 and other communication devices. Similarly, the network nodes 408, 410 are3000-2702-P / Pl 13407US01 25arranged, capable, configured, and / or operable to communicate directly or indirectly (e.g., via other devices of telecommunications network 402) with the UEs 412 and / or with other network nodes or equipment in the telecommunications network 402 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 402. More specifically, UEs 412 may send messages, data, and / or other signals to network nodes 408, 410 or other elements of the telecommunications network 402 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 408, 410 may send messages, data, and other signals to UEs 4122, other network nodes 408, 410, and other devices in telecommunications network 402 directly or indirectly. As one specific example, a core network node 408 may transmit a particular message to a UE 412 by transmitting the message to an access network node 410 that will then transmit the message to the intended UE 412. Similarly, a core network node 408 may receive a particular message from a UE 412 by receiving the message from an access network node 410 that itself received the message from the UE 412.

[0097] In the depicted example, the core network 406 connects elements of the access network 404 (e.g., one or more of the network nodes 410) to one or more host computing systems, such as host 416. 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 406 includes one or more core network nodes (e.g., core network node 408) of various types, one or more of which may be generally referred to as network nodes 408. Network nodes 408 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 408. 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).

[0098] The host 416 may be under the ownership or control of a service provider other than an operator or provider of the access network 404 and / or the telecommunications network 402. The host 416 may be operated by the service provider or on behalf of the service provider. The3000-2702-P / Pl 13407US01 26host 416 may host a variety of applications to provide one or more services. 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.

[0099] As a whole, the communication system 400 of Figure 4 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system 400 may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and / or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (Wi-Fi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (Wi-Max), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, Li-Fi, and / or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox. Moreover, the communication system 400 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 400 supporting different standards, protocols, or rule sets.

[0100] As one example, in certain embodiments, access network 404 may contain some access network nodes 410 that support 3 GPP radio access technologies (RAT), such as LTE or NR, while other access network nodes 410 support (or the same access network nodes 410 additionally support) non-3GPP RATs, such as Wi-Fi or a proprietary RAT. As another example, telecommunications network 402 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 404 and / or a core network 406 that supports multiple different standard generations or may include multiple access networks 404 and / or multiple core networks 406 with individual networks 404, 406 supporting different standard generations.

[0101] Telecommunications network 402 may support network slicing to provide different logical networks to different devices that are connected to the telecommunications network 402. For example, the telecommunications network 402 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband3000-2702-P / Pl 13407US01 27(eMBB) services to other UEs, and / or Massive Machine Type Communication (mMTC) / Massive loT services to yet further UEs.

[0102] In some examples, one or more of the UEs 412 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 404 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 404. 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).

[0103] In the example, the hub 414 communicates with the access network 404 to facilitate indirect communication between one or more UEs (e.g., UE 412C and / or 412D) and network nodes (e.g., network node 410B). In some examples, the hub 414 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 414 may be a broadband router enabling access to the core network 406 for the UEs. As another example, the hub 414 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 410, or by executable code, script, process, or other instructions in the hub 414.

[0104] As another example, the hub 414 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 414 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, the hub 414 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 414 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub 414 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.

[0105] The hub 414 may have a constant / persistent or intermittent connection to the network node 410B. The hub 414 may also allow for a different communication scheme and / or schedule between the hub 414 and UEs (e.g., UE 412C and / or 412D), and between the hub 414 and the core network 406. In other examples, the hub 414 is connected to the core network 406 and / or one or more UEs via a wired connection. Moreover, the hub 414 may be configured to connect to an M2M service provider over the access network 404 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 410 while still connected via the hub 414 via a wired or wireless connection. In some embodiments, the hub 4143000-2702-P / Pl 13407US01 28may be a dedicated hub - that is, a hub whose primary function is to route communications to / from the UEs from / to the network node 41 OB. In other embodiments, the hub 414 may be a nondedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 41 OB, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0106] Figure 5 is another example of a communication system 500 according to some embodiments. As used herein, the communication system 500 includes multiple access points (APs) 510 (with four exemplary APs 510A, 510B, 510C, and 510D being depicted) and multiple wireless devices, referred to in the context of communication system 500 as stations (STAs) 512 (referred to individually as STA 512A, STA 512B, STA 512C, STA 512D, and STA 512E). STA 512A is served by AP 510A in a first basic service set (BSS) 520A. STA 510B and STA 510C are served by AP 510B in a second BSS, BSS 520B. STA 512D is served by AP 510C in a third BSS, BSS 520C. STA 512E is served by AP 510D in a fourth BSS, BSS 520D. Stations 512 may be non-AP STAs and correspond to various kinds of wireless devices, for example, user terminals, such as mobile or stationary computing devices like smartphones, laptop computers, desktop computers, tablet computers, gaming devices, head-mounted displays (HMDs) for Augmented Reality (AR) or Virtual Reality (VR), or the like. Further, stations 512 could, for example, correspond to other kinds of equipment like smart home devices, printers, multimedia devices, data storage devices, or the like.

[0107] Each of STAs 512 may connect through a radio link to one of APs 510. For example, depending on location or channel conditions experienced by a given STA 512, the STA may select an appropriate AP and BSS for establishing the radio link. The radio link may be based on one or more orthogonal frequency-division multiplexing (OFDM) carriers from a frequency spectrum that is shared on the basis of a contention-based mechanism, e.g., an unlicensed or license exempt band like 2.4 GHz Industrial, Scientific, and Medical (ISM) band, the 5 GHz band, the 6 GHz band, or the 60 GHz band.

[0108] Each AP 510 may provide data connectivity to STAs 512 connected to a particular AP 510. As illustrated, APs 510 may be connected to a data network 530. In this way, APs 510 may also provide data connectivity between STAs 512 and other entities, e.g., to one or more servers, service providers, data sources, data sinks, user terminals, or the like. Accordingly, the radio link established between a given STA 512 and its serving AP 510 may be used for providing various kinds of services to STA 512, e.g., a voice service, a multimedia service, or other data service. Such services may be based on applications that are executed on STA 512 and / or on a device linked to STA 512. By way of example, Figure 5 illustrates an application service platform 5323000-2702-P / Pl 13407US01 29provided in data network 530. The application(s) executed on STA 512 and / or on one or more other devices linked to STA 512 may use the radio link for data communication with one or more other STA 512 and / or the application service platform 532, thereby enabling utilization of the corresponding service(s) at STA 512.

[0109] Figure 6 shows a wireless device 600, which may be configured to operate in communication system 400 of Figure 4 or in communication system 500 of Figure 5. The wireless device 600 may be alternatively referred to as a UE 600, like a UE 412 within the context of communication system 400, or as a station (STA) 600 or as a non-access-point station (non-AP STA) 600, like a STA 512 within the context of the communication system 500, 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 customer-premise 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.

[0110] A wireless device 600 may support device-to-device (D2D) communication, for example by implementing a 3 GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle-to-everything (V2X). In other examples, wireless device 600 may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, wireless device 600 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 600 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).[OHl] In particular embodiments, wireless device 600 includes processing circuitry 602 that is operatively coupled via a bus 604 to an input / output interface 606, a power source 608, a memory 610, a communication interface 612, and / or any other component, or any combination3000-2702-P / Pl 13407US01 30thereof. Certain embodiments of wireless device 600 may include all or a subset of the components shown in Figure 6. The level of integration between the components may vary from one embodiment of wireless device 600 to another. In general, in a particular embodiment of wireless device 600, processing circuitry 602, input / output interface 606, power source 608, memory 610, and communication interface 612 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 600. Further, certain embodiments of wireless devices 600 may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0112] The processing circuitry 602 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 610. The processing circuitry 602 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 602 may include multiple central processing units (CPUs).

[0113] In the example, the input / output interface 606 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 600. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0114] In some embodiments, the power source 608 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 608 may further include power circuitry for delivering power3000-2702-P / Pl 13407US01 31from the power source 608 itself, and / or an external power source, to the various parts of wireless device 600 via input circuitry or an interface such as an electrical power cable. Power source 608 may perform any formatting, converting, or other modification to make accessible power suitable for the respective components of the wireless device 600 to which power is supplied.

[0115] The memory 610 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 610 includes one or more programs 614, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 616. The memory 610 may store, for use by wireless device 600, any of a variety of various operating systems or combinations of operating systems.

[0116] The memory 610 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and / or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ The memory 610 may allow wireless device 600 to access instructions, programs, and the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in the memory 610, which may be or comprise a device-readable storage medium.

[0117] The processing circuitry 602 may be configured to communicate with an access network or other network via or using the communication interface 612. The communication interface 612 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 622. The communication interface 612 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 618 and / or a receiver 620 appropriate to provide network communications (e.g., optical, electrical, frequency3000-2702-P / Pl 13407US01 32allocations, and so forth). Moreover, the transmitter 618 and receiver 620 may be coupled to one or more antennas (e.g., antenna 622) and may share circuit components, software, or firmware, or alternatively be implemented separately.

[0118] In the illustrated embodiment, communication functions of the communication interface 612 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.

[0119] In particular embodiments, wireless device 600 may provide an output of data captured via a sensor, through its communication interface 612, via a wireless connection to a network node, and / or in any appropriate manner. Data captured by sensors of a wireless device 600 can be communicated through a wireless connection to a network node via another wireless device 600. 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).

[0120] As another example, wireless device 600 comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, wireless device 600 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.

[0121] Wireless device 600, 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. Non-limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice3000-2702-P / Pl 13407US01 33controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door / window sensor, a flood / moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item-tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. In particular embodiments, wireless device 600 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 600 shown in Figure 6.

[0122] As yet another specific example, in an loT scenario, wireless device 600 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 600 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 600 may implement the 3GPP NB-IoT standard. In other scenarios, wireless device 600 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.

[0123] In practice, any number of wireless devices 600 may be used together with respect to a single use case. For example, a first wireless device 600 might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second wireless device 600 that is a remote controller operating the drone. When a user makes changes from the remote controller, the first wireless device 600 may adjust the throttle on the drone (e.g., by controlling an actuator) to increase or decrease the drone’s speed. The first and / or the second wireless device 600 can also include more than one of the functionalities described above. For example, wireless device 600 might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

[0124] Figure 7 shows a network node 700 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 700 may be configured to operate in communication system 400 of Figure 4, like network nodes 408 or 410, or in communication system 500 of Figure 5, like an AP 510 or a station 512. Examples of network3000-2702-P / Pl 13407US01 34nodes 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 0-RAN node (e.g., 0-RU, 0-DU, O-CU).

[0125] Network nodes 700 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 700 may be a relay node or a relay donor node controlling a relay. Network nodes 700 may also include one or more (or all) parts of a distributed radio base station such as centralized digital units, distributed units (e.g., in an 0-RAN access node) and / or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

[0126] Other examples of network nodes 700 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).

[0127] In particular embodiments, network node 700 includes a processing circuitry 702, a memory 704, a communication interface 706, and a power source 708. In general, in a particular embodiment of network node 700, processing circuitry 702, memory 704, communication interface 706, and power source 708 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 700.

[0128] The network node 700 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 700 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 700 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memories 704 or portions of memory 704 for different RATs) and3000-2702-P / Pl 13407US01 35some components may be reused (e.g., a same antenna 710 may be shared by different RATs). The network node 700 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 700, 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 700.

[0129] The processing circuitry 702 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and / or encoded logic operable to provide, either alone or in conjunction with other components, such as the memory 704, to provide network node 700 functionality.

[0130] In some embodiments, the processing circuitry 702 includes a system on a chip (SOC).In some embodiments, the processing circuitry 702 includes one or more of radio frequency (RF) transceiver circuitry 712 and baseband processing circuitry 714. In some embodiments, the RF transceiver circuitry 712 and the baseband processing circuitry 714 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 712 and baseband processing circuitry 714 may be on the same chip or set of chips, boards, or units.

[0131] The memory 704 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device-readable and / or computer-executable memory devices that store information, data, and / or instructions that may be used by the processing circuitry 702. The memory 704 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions capable of being executed by the processing circuitry 702 and utilized by the network node 700. The memory 704 may be used to store any calculations made by the processing circuitry 702 and / or any data received via the communication interface 706. In some embodiments, the processing circuitry 702 and memory 704 are integrated.3000-2702-P / Pl 13407US01 36

[0132] The communication interface 706 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 706 comprises port(s) / terminal(s) 716 to send and receive data, for example to and from a network over a wired connection. In particular embodiments, network node 600 may be capable of wireless communication and communication interface 706 may also include radio front-end circuitry 718 that may be coupled to, or in certain embodiments a part of, an antenna 710. Particular embodiments of radio front-end circuitry 718 include filter(s) 720 and amplifier(s) 722. The radio front-end circuitry 718 may be connected to an antenna 710 and processing circuitry 702. The radio front-end circuitry may be configured to condition signals communicated between antenna 710 and processing circuitry 702. The radio front-end circuitry 718 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 718 may convert the digital data into a radio signal(s) having the appropriate channel and bandwidth parameters using a combination of filters 720 and / or amplifiers 722. The radio signal(s) may then be transmitted via the antenna 710. Similarly, when receiving data, the antenna 710 may collect radio signals which are then converted into digital data by the radio front-end circuitry 718. The digital data may be passed to the processing circuitry 702. In other embodiments, the communication interface may comprise different components and / or different combinations of components.

[0133] In certain alternative embodiments, network node 700 may be capable of wireless communication but does not include separate radio front-end circuitry 718, instead, the processing circuitry 702 includes radio front-end circuitry and is connected to the antenna 710. Similarly, in some embodiments, all or some of the RF transceiver circuitry 712 is part of the communication interface 706. In still other embodiments, the communication interface 706 includes one or more ports or terminals 716, the radio front-end circuitry 718, and the RF transceiver circuitry 712, as part of a radio unit (not shown), and the communication interface 706 communicates with the baseband processing circuitry 714, which is part of a digital unit (not shown).

[0134] The antenna 710 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 710 may be coupled to the radio front-end circuitry 718 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 710 is separate from the network node 700 and connectable to the network node 700 through one or more interfaces or ports.

[0135] The antenna 710, communication interface 706, and / or the processing circuitry 702 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 700. Any information, data, and / or3000-2702-P / Pl 13407US01 37signals may be received from a UE, another network node, and / or any other network equipment. Similarly, the antenna 710, the communication interface 706, and / or the processing circuitry 702 may be configured to perform some or all of the transmitting or sending operations described herein as being performed by the network node 700. Any information, data and / or signals may be transmitted to a UE, another network node, and / or any other network equipment.

[0136] The power source 708 provides power to the various components of network node 700 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 708 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 700 with power for performing the functionality described herein. For example, the network node 700 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 708. As a further example, the power source 708 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.

[0137] Embodiments of the network node 700 may include additional components beyond those shown in Figure 7 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 700 may include user interface equipment to allow input of information into the network node 700 and to allow output of information from the network node 700. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 700.

[0138] Figure 8 is a block diagram illustrating a virtualization environment 800 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 800 hosted by one or more of hardware nodes, such as a hardware computing device that operates as an access network node, UE, core network node, or host. Further, in embodiments in which a virtual node does not require radio connectivity (e.g., a core network node or host), then3000-2702-P / Pl 13407US01 38the node may be entirely virtualized. In some embodiments, the virtualization environment 800 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an 0-2 interface.

[0139] Applications 802 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment 700 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein.

[0140] Hardware 804 includes processing circuitry, memory that stores software and / or instructions executable by hardware processing circuitry, and / or other hardware devices as described herein, such as a network interface, input / output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 806 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VM 808A and VM 808B (which may be collectively referred to as VMs 808), and / or perform any of the functions, features and / or benefits described in relation with some embodiments described herein. The virtualization layer 806 may present a virtual operating platform that appears like networking hardware to one or more of the VMs 808.

[0141] The VMs 808 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by virtualization layer 806. Different embodiments of the instance of a virtual appliance 802 may be implemented on one or more of VMs 808, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

[0142] In the context of NFV, each of the VMs 808 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of the VMs 808, and that part of hardware 804 that executes that VM, be it hardware dedicated to that VM and / or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more of the VMs 808 on top of the hardware 804 and corresponds to an application 802.

[0143] Hardware 804 may be implemented in a standalone network node with generic or specific components. Hardware 804 may implement some functions via virtualization. Alternatively, hardware 804 may be part of a larger cluster of hardware (e.g., such as in a data3000-2702-P / Pl 13407US01 39center or CPE) where many hardware nodes work together and are managed via management and orchestration 810, which, among others, oversees lifecycle management of applications 802. In some embodiments, hardware 804 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 812 which may alternatively be used for communication between hardware nodes and radio units.

[0144] 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.

[0145] 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 particular3000-2702-P / Pl 13407US01 40embodiments, 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.

[0146] 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.

[0147] Some exemplary embodiments of the present disclosure are as follows:Group A Embodiments

[0148] Embodiment 1: A method performed by a User Equipment, UE, (200), the method comprising: receiving (206; 300) a configuration for a Conditional Layer 1, LI, / Layer 2, L2, Triggered Mobility, CLTM, candidate cell, wherein the configuration includes a candidate cell configuration for the CLTM candidate cell, an associated CLTM execution condition, and a candidate cell identifier of the CLTM candidate cell; monitoring (304) the CLTM execution condition; while monitoring (304) the CLTM execution condition, receiving (212; 312) from a network node an LTM Cell Switch command including the candidate cell identifier; and in response to the LTM Cell Switch command, performing (214-216; 314-316) an LTM Cell Switch to the CLTM candidate cell by applying the candidate cell configuration.

[0149] Embodiment 2: The method of embodiment 1, wherein the LTM Cell Switch command includes a Timing Advance, TA, value for the CLTM candidate cell indicated by the candidate cell identifier, and the UE (200) receives the LTM Cell Switch command while the UE (200) has a stored TA value for the same CLTM candidate cell with an associated TA timer running.

[0150] Embodiment 3: The method of embodiment 1, wherein the LTM Cell Switch command does not include a TA value for the CLTM candidate cell indicated by the candidate cell identifier, and the UE (200) receives the LTM Cell Switch command while the UE (200) has a stored TA value for the same CLTM candidate cell with an associated TA timer running.

[0151] Embodiment 4: The method of embodiment 3, wherein performing the LTM Cell Switch to the CLTM candidate cell comprises applying the stored TA value for the same candidate cell, even if the LTM Cell Switch command does not include a TA value.3000-2702-P / Pl 13407US01 41

[0152] Embodiment 5: The method of embodiment 3, wherein the UE (200) releases the stored TA value for the same candidate cell, in case the LTM Cell Switch command does not include a TA value.

[0153] Embodiment 6: The method of embodiment 5, wherein the performing the LTM Cell Switch to the CLTM candidate cell comprises performing the LTM Cell Switch to the CLTM candidate cell as a RACH-based procedure.

[0154] Embodiment 7: The method of embodiment 1, wherein the LTM Cell Switch command does not include a TA value for the CLTM candidate cell indicated by the candidate cell identifier, and the UE (200) receives the LTM Cell Switch command while the UE has a stored TA value for the same CLTM candidate cell with an associated TA timer running, and where the UE (200) receives, before or at the LTM cell switch procedure, an indication from a network node about whether the UE should apply the stored TA value or not.

[0155] Embodiment 8: The method of embodiment 7, wherein the indication about whether the UE should apply the stored TA value or not is included within the LTM Cell Switch command.

[0156] Embodiment 9: The method of embodiment 7, wherein the indication about whether the UE should apply the stored TA value or not is included with an associated (C)LTM configuration, e.g. in LTM-Config, or in the configuration (e.g., an LTM candidate configuration) for the CLTM candidate cell, e.g. within the corresponding LTM-Candidate .

[0157] Embodiment 10: The method of any of embodiments 7 to 9, wherein the indication indicates that the UE should apply the stored TA value, and performing (214-216; 314-316) the LTM Cell Switch to the CLTM candidate cell comprises performing (214-216; 314-316) the LTM Cell Switch to the CLTM candidate cell as a Random Access Channel, RACE!, -less procedure.

[0158] Embodiment 11 : The method of any of embodiments 7 to 9, wherein the indication indicates that the UE should not apply the stored TA value, and performing (214-216; 314-316) the LTM Cell Switch to the CLTM candidate cell comprises performing (214-216; 314-316) the LTM Cell Switch to the CLTM candidate cell as a Random Access Channel, RACH, -based procedure.

[0159] Embodiment 12: The method of embodiment 2, wherein performing the LTM Cell Switch to the CLTM candidate cell comprises handling the TA value received in the LTM Cell Switch command by applying the received TA value and / or overriding a stored TA value for the same candidate cell.

[0160] Embodiment 13: The method of any of embodiments 1 to 6 or 12, further comprising, upon receiving the LTM Cell Switch Command, handling an LTM candidate Timing Alignment3000-2702-P / Pl 13407US01 42Timer (LTM-TAT) associated with a validity of the stored TA value and associated with the CLTM candidate cell.

[0161] Embodiment 14: The method of embodiment 13, wherein handling the LTM candidate Timing Alignment Timer (LTM-TAT) comprises stopping the LTM-TAT for the CLTM candidate cell indicated in the LTM Cell Switch command.

[0162] Embodiment 15: The method of embodiment 1, wherein the LTM Cell Switch command comprises a TA value for the CLTM candidate cell, and the method further comprises determining whether to apply or not the TA value in the LTM Cell Switch command including the candidate cell identifier for the CLTM candidate cell, and whether or not to override a previously received TA value for the same candidate cell.

[0163] Embodiment 16: The method of embodiment 1, further comprising receiving (310) a TA value for the same CLTM candidate cell in a message other than the LTM Cell Switch command and storing (310) the TA value (e.g., in association with the candidate cell identity).

[0164] Embodiment 17: The method of embodiment 16, wherein receiving (310) the stored TA value comprises receiving (310) the stored TA value via a MAC CE which is not the LTM Cell Switch command.

[0165] Embodiment 18: The method of embodiment 17, wherein the MAC CE which includes the stored TA value is received by the UE (200) before the LTM Cell Switch command.

[0166] Embodiment 19: The method of embodiment 17, wherein the MAC CE which includes the stored TA value is received by the UE (200) after the LTM Cell Switch command.

[0167] Embodiment 20: The method of any of the previous embodiments, further comprising: providing user data; and forwarding the user data to a host via the transmission to the network node.Group B Embodiments

[0168] Embodiment 21: A method performed by a network node (202), the method comprising: transmitting (206; 300) to a UE (200) a configuration for a CLTM candidate cell, wherein the configuration includes a candidate cell configuration for the CLTM candidate cell, an associated CLTM execution condition, and a candidate cell identifier; and transmitting to the UE an LTM Cell Switch command including the candidate cell identifier, for triggering an LTM to the CLTM candidate cell.

[0169] Embodiment 22: The method of embodiment 21, wherein the LTM Cell Switch command includes a TA value for the CLTM candidate cell indicated by the candidate cell identifier.3000-2702-P / Pl 13407US01 43

[0170] Embodiment 23: The method of embodiment 22, wherein the LTM Cell Switch command is transmitted to the UE while the UE has a stored TA value for the same CLTM candidate cell.

[0171] Embodiment 24: The method of embodiment 22 or 23, further comprising transmitting (310) to the UE a message other than the Cell Switch Command, wherein this message comprises a TA to be stored by the UE for the same CLTM candidate cell.

[0172] Embodiment 25: The method of embodiment 24, wherein transmitting (310) message including the TA value for the same CLTM candidate cell comprises transmitting (310) a MAC CE that includes the TA value for the same CLTM candidate cell, wherein the MAC CE is not the LTM Cell Switch command.

[0173] Embodiment 26: The method of embodiment 25, wherein the MAC CE which includes the TA value is transmitted to the UE (200) before the LTM Cell Switch command.

[0174] Embodiment 27 : The method of embodiment 25, wherein the MAC CE which includes the stored TA value is transmitted to the UE (200) after the LTM Cell Switch command.

[0175] Embodiment 28: The method of embodiment 21, wherein the LTM Cell Switch command does not include a TA value for the CLTM candidate cell indicated by the candidate cell identifier.

[0176] Embodiment 29: The method of embodiment 28, wherein the LTM Cell Switch command is transmitted to the UE while the UE has a stored TA value for the same CLTM candidate cell.

[0177] Embodiment 30: The method of any of the previous embodiments, further comprising: obtaining user data; and forwarding the user data to a host or a user equipment.Group C Embodiments

[0178] Embodiment 31: A wireless device comprising: processing circuitry configured to perform any of the operations of any of the Group A embodiments; and a power source configured to supply power to the processing circuitry.

[0179] Embodiment 32: 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.

[0180] Embodiment 33 : A wireless device comprising: one or more antennas; communication 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 of3000-2702-P / Pl 13407US01 44information 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; and a power source connected to the processing circuitry and configured to supply power to the UE.

Claims

3000-2702-P / Pl 13407US01 45CLAIMS1. A method performed by a User Equipment, UE, (200), the method comprising:receiving (206; 300) a configuration for a Conditional Layer 1, LI, / Layer 2, L2, Triggered Mobility, CLTM, candidate cell, wherein the configuration includes a candidate cell configuration for the CLTM candidate cell, an associated CLTM execution condition, and a candidate cell identifier of the CLTM candidate cell;monitoring (304) the CLTM execution condition;while monitoring (304) the CLTM execution condition, receiving (212; 312) from a network node an L1 / L2 Triggered Mobility, LTM, Cell Switch command including the candidate cell identifier; andin response to the LTM Cell Switch command, performing (214-216; 314-316) an LTM Cell Switch to the CLTM candidate cell by applying the candidate cell configuration.

2. The method of claim 1, wherein the LTM Cell Switch command includes a Timing Advance, TA, value for the CLTM candidate cell indicated by the candidate cell identifier, and the UE (200) receives the LTM Cell Switch command while the UE (200) has a stored TA value for the same CLTM candidate cell with an associated TA timer running.

3. The method of claim 2, wherein performing the LTM Cell Switch to the CLTM candidate cell comprises handling the TA value received in the LTM Cell Switch command by applying the received TA value and / or overriding a stored TA value for the same candidate cell.

4. The method of claim 3, wherein performing the LTM Cell Switch to the CLTM candidate cell comprises performing the LTM Cell Switch to the CLTM candidate cell as a RACH-less procedure.

5. The method of claim 1, wherein the LTM Cell Switch command does not include a TA value for the CLTM candidate cell indicated by the candidate cell identifier, and the UE (200) receives the LTM Cell Switch command while the UE (200) has a stored TA value for the same CLTM candidate cell with an associated TA timer running.

6. The method of claim 5, wherein performing the LTM Cell Switch to the CLTM candidate cell comprises applying the stored TA value for the same candidate cell.3000-2702-P / Pl 13407US01 467. The method of claim 6, wherein performing the LTM Cell Switch to the CLTM candidate cell comprises performing the LTM Cell Switch to the CLTM candidate cell as a RACH-less procedure.

8. The method of claim 5, wherein the UE (200) releases the stored TA value for the same candidate cell.

9. The method of claim 8, wherein the performing the LTM Cell Switch to the CLTM candidate cell comprises performing the LTM Cell Switch to the CLTM candidate cell as a RACH-based procedure.

10. The method of any of claims 2 to 9, further comprising, upon receiving the LTM Cell Switch Command, handling an LTM candidate Timing Alignment Timer (LTM-TAT) associated with a validity of the stored TA value and associated with the CLTM candidate cell.

11. The method of claim 10, wherein handling the LTM candidate Timing Alignment Timer (LTM-TAT) comprises stopping the LTM-TAT for the CLTM candidate cell indicated in the LTM Cell Switch command.

12. The method of claim 1, wherein the LTM Cell Switch command does not include a TA value for the CLTM candidate cell indicated by the candidate cell identifier, and the UE (200) receives the LTM Cell Switch command while the UE has a stored TA value for the same CLTM candidate cell with an associated TA timer running, and where the UE (200) receives, before or at the LTM cell switch procedure, an indication from a network node about whether the UE should apply the stored TA value or not.

13. The method of claim 12, wherein the indication about whether the UE should apply the stored TA value or not is included within the LTM Cell Switch command.

14. The method of claim 12, wherein the indication about whether the UE should apply the stored TA value or not is included with an associated CLTM or LTM configuration or in the configuration for the CLTM candidate cell.

15. The method of any of claims 12 to 14, wherein the indication indicates that the UE should3000-2702-P / Pl 13407US01 47apply the stored TA value, and performing (214-216; 314-316) the LTM Cell Switch to the CLTM candidate cell comprises performing (214-216; 314-316) the LTM Cell Switch to the CLTM candidate cell as a Random Access Channel, RACH,-less procedure.

16. The method of any of claims 12 to 14, wherein the indication indicates that the UE should not apply the stored TA value, and performing (214-216; 314-316) the LTM Cell Switch to the CLTM candidate cell comprises performing (214-216; 314-316) the LTM Cell Switch to the CLTM candidate cell as a Random Access Channel, RACH, -based procedure.

17. The method of claim 1, wherein the LTM Cell Switch command comprises a TA value for the CLTM candidate cell, and the method further comprises determining whether to apply or not the TA value in the LTM Cell Switch command including the candidate cell identifier for the CLTM candidate cell, and whether or not to override a previously received TA value for the same candidate cell.

18. The method of claim 1, further comprising receiving (310) a TA value for the same CLTM candidate cell in a message other than the LTM Cell Switch command and storing (310) the TA value.

19. The method of claim 18, wherein receiving (310) the TA value comprises receiving (310) the TA value via a Medium Access Control, MAC, Control Element, CE, which is not the LTM Cell Switch command.

20. The method of claim 19, wherein the MAC CE which includes the TA value is received by the UE (200) before the LTM Cell Switch command.

21. The method of claim 19, wherein the MAC CE which includes the TA value is received by the UE (200) after the LTM Cell Switch command.

22. A User Equipment, UE, (200; 600), comprising:a communication interface (612) comprising a transmitter (618) and a receiver (620); and processing circuitry (602) associated with the communication interface (612), the processing circuitry (602) configured to cause the UE (200; 600) to:3000-2702-P / Pl 13407US01 48receive (206; 300) a configuration for a Conditional Layer 1, LI, / Layer 2, L2, Triggered Mobility, CLTM, candidate cell, wherein the configuration includes a candidate cell configuration for the CLTM candidate cell, an associated CLTM execution condition, and a candidate cell identifier of the CLTM candidate cell;monitor (304) the CLTM execution condition;while monitoring (304) the CLTM execution condition, receive (212; 312) from a network node an L1 / L2 Triggered Mobility, LTM, Cell Switch command including the candidate cell identifier; andin response to the LTM Cell Switch command, perform (214-216; 314-316) an LTM Cell Switch to the CLTM candidate cell by applying the candidate cell configuration.

23. A method performed by a network node (202), the method comprising:transmitting (206; 300) to a User Equipment, UE, (200) a configuration for a Conditional Layer 1, LI, / Layer 2, L2, Triggered Mobility, CLTM, candidate cell, wherein the configuration includes a candidate cell configuration for the CLTM candidate cell, an associated CLTM execution condition, and a candidate cell identifier; andtransmitting to the UE (200) an L1 / L2 Triggered Mobility, LTM, Cell Switch command including the candidate cell identifier, for triggering an LTM to the CLTM candidate cell.

24. The method of claim 23, wherein the LTM Cell Switch command includes a Timing Advance, TA, value for the CLTM candidate cell indicated by the candidate cell identifier.

25. The method of claim 24, wherein the LTM Cell Switch command is transmitted to the UE while the UE has a stored TA value for the same CLTM candidate cell.

26. The method of claim 24 or 25, further comprising transmitting (310) to the UE a message other than the LTM Cell Switch command, wherein this message comprises a TA value to be stored by the UE for the same CLTM candidate cell.

27. The method of claim 26, wherein transmitting (310) message including the TA value for the same CLTM candidate cell comprises transmitting (310) a Medium Access Control, MAC, Control Element, CE, that includes the TA value for the same CLTM candidate cell, wherein the MAC CE is not the LTM Cell Switch command.3000-2702-P / Pl 13407US01 4928. The method of claim 27, wherein the MAC CE which includes the TA value is transmitted to the UE (200) before the LTM Cell Switch command.

29. The method of claim 27, wherein the MAC CE which includes the stored TA value is transmitted to the UE (200) after the LTM Cell Switch command30. The method of claim 23, wherein the LTM Cell Switch command does not include a TA value for the CLTM candidate cell indicated by the candidate cell identifier.

31. The method of claim 30, wherein the LTM Cell Switch command is transmitted to the UE while the UE has a stored TA value for the same CLTM candidate cell.

32. A network node (202; 700) comprising processing circuitry (702) configured to cause the network node (202; 700) to:transmit (206; 300) to a User Equipment, UE, (200) a configuration for a Conditional Layer 1, LI, / Layer 2, L2, Triggered Mobility, CLTM, candidate cell, wherein the configuration includes a candidate cell configuration for the CLTM candidate cell, an associated CLTM execution condition, and a candidate cell identifier; andtransmit to the UE (200) an L1 / L2 Triggered Mobility, LTM, Cell Switch command including the candidate cell identifier, for triggering an LTM to the CLTM candidate cell.

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