Method and apparatus for enhancement for conditional cell switch preparation

Abstract

Described is an approach for improved Layer 1 / Layer 2 Triggered Mobility (LTM) and conditional LTM (CLTM) cell switch preparation task performance. When a user equipment (UE) is configured with CLTM event trigger(s) for candidate cells and / or reference signals (RS), UE can begin performing these tasks for each candidate cell / RS. After being so configured, UE can determine a candidate cell / RS satisfies an event trigger for LTM or CLTM or the UE can receive a cell switch command. If, at this time, all (or a required subset) of the LTM / CLTM cell switch preparation tasks have already been completed, the subsequent period for LTM / CLTM cell switch does not include additional time for performing these tasks. Alternatively, if, at this time, all (or a required subset) of the LTM / CLTM cell switch preparation tasks have not been completed, the subsequent period for LTM / CLTM cell switch may include additional time for performing these tasks.

Description

METHOD AND APPARATUS FOR ENHANCEMENT FOR CONDITIONAL CELL SWITCH PREPARATION Technological Field

[0001] An example embodiment relates to, generally, wireless communications and, more particularly, but not exclusively, to a method, apparatus and computer program product for enhancement for conditional cell switch preparation.Background

[0002] Some wireless devices, such as a user equipment (UE) may be configured to carry out connected state mobility, otherwise known as handover or cell switch procedures, between two or more different cells (e.g., base station, tower, eNodeB, gNodeB, etc.) of a mobile network. A UE can be configured (e.g., by a particular network) with a list of configured candidate cells which are candidate cells for a handover or cell switch procedure (e.g., possible cells on which the UE can hand over and which can provide services to the UE). A UE typically reports out to the network on cell-level signal or service quality to the network based on measurements. For example, when cell quality for a currently serving cell becomes diminished, handover or cell switch between the currently serving cell and another cell can be carried out to improve continuity and quality of service.

[0003] Typically, a handover or cell switch decision is made by the network based on UE reported measurements, and the handover or cell switch is initiated by a network command.

[0004] In some cases, a UE may be configured (e.g., pre-configured) by the mobile network for a conditional handover procedure based on one or more signal threshold conditions for one or more candidate cells. Thereafter, if the UE determines a candidate cell has satisfied the signal threshold conditions that the mobile network configured at the UE, the UE can execute a conditional handover procedure to the candidate cell that the UE determined has satisfied the signal threshold conditions. Conditional handover may be carried out at the UE using lower-layer triggered mobility (LTM), where the UE may be configured to perform preparation steps before initiating the conditional cell switch, to enable shorter interruptions due to the cell switch. However, UEs may not be configured for tasks related to preparing for LTM cell switching and other conditional handover events for a large number of different configured candidate cells.Brief Summary

[0005] According to some aspects, there is provided the subject matter of the independent claims. Some further aspects are defined in the dependent claims. The embodiments that do not fall under the scope of the claims are to be interpreted as examples useful for understanding the disclosure.

[0006] According to an embodiment, a device or apparatus, such as a user equipment (UE) is provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the UE to perform receiving a Layer 1 / Layer 2 triggered mobility (LTM) configuration associated with one or more candidate cells, wherein the UE is configured to initiate a Conditional LTM (CLTM) cell switch to at least one candidate cell based upon at least one CLTM condition being satisfied.In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform initiating monitoring of the at least one CLTM condition for CLTM cell switch to the at least one candidate cell or at least one reference signal (RS) configmed for the at least one candidate cell. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, based on initiating the monitoring of the at least one CLTM condition for CLTM cell switch, initiating one or more CLTM cell switch preparation actions for the at least one candidate cell or the at least one RS configured for the at least one candidate cell. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, after completion of performance of the one or more CLTM cell switch preparation actions, maintaining the one or more CLTM cell switch preparation actions until a predefined event. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which a cell switch is initiated after completion of performance of the one or more CLTM cell switch preparation actions and before occurrence of a predefined event other than initiation or completion of the cell switch, completing the cell switch within a cell switch delay period that does not comprise one or more cell switch delay subperiods associated with the one or more CLTM cell switch preparation actions.

[0007] In some embodiments, the one or more CLTM cell switch preparation actions comprise at least one of: monitoring fine downlink timing for the particular candidate cell, monitoring frequency synchronization for the particular candidate cell, monitoring fine downlink timing for a reference signal (RS) associated with the particular candidate cell, monitoring frequency synchronization for the RS associated with the particular candidate cell, ASN.1 decoding, ASN.1 validity check, storing a decoded configuration of the candidate cell at the UE, monitoring a path loss estimate associated with the RS associated with the particular candidate cell, performing timing advance (TA) delay estimation for the particular candidate cell, determining a delay for UE- based TA estimation for the particular candidate cell, or estimating path loss reference signal (PL-RS) delay for the particular candidate cell.

[0008] In some embodiments, the predefined event until which the UE maintains the one or more CLTM cell switch preparation actions is at least one of: initiation / completion of cell switch based on reception of cell switch command or condition of CLTM cell switch becoming fulfilled, configuration of UE stopping CLTM condition evaluation for the candidate cell or RS configured for the candidate cell, or preconfigured / predefined time for preparation action maintenance expiring. In some embodiments, the one or more CLTM switch preparation actions are carried out by the UE in parallel, in series, or partially in parallel and partially in series.

[0009] In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform receiving, at the UE, from a network element of the mobile network, information about which of a plurality of CLTM switch preparation actions the UE is to perform at the initiation of the monitoring of the at least one CLTM condition for CLTM cell switch. In some embodiments,the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, upon receiving the information about which of a plurality of CLTM switch preparation actions to perform, initiating the indicated CLTM cell switch preparation tasks in the received information.

[0010] In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform receiving, at the UE, from a network element of the mobile network, information about an order in which the UE is to perform the one or more CLTM switch preparation actions. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the information about the order in which the UE is to perform the one or more CLTM switch preparation actions indicates that all of the one or more CLTM switch preparation actions are to be performed in parallel, determining, at the UE, based at least on a respective delay estimate for each of the one or more CLTM switch preparation actions, a total CLTM switch preparation delay estimate associated with the particular candidate cell to be a maximum delay estimate from among the respective delay actions for the one or more CLTM switch preparation actions. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the information about the order in which the UE is to perform the one or more CLTM switch preparation actions indicates that all of the one or more CLTM switch preparation actions are to be performed serially, determining, at the UE, based at least on a sum of the respective delay estimates for the one or more CLTM switch preparation actions, a total CLTM switch preparation delay estimate associated with the particular candidate cell.

[0011] In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the UE receives a cell switch command to perform a cell switch from a serving cell to the particular candidate cell or another candidate cell, determining that one or more required CLTM cell switch preparation tasks remain incomplete for the particular candidate cell or the another candidate cell, completing the incomplete preparation tasks during the cell switch. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the UE receives a cell switch command to perform a cell switch from a serving cell to the particular candidate cell or another candidate cell, determining that all required CLTM cell switch preparation tasks have been completed for the particular candidate cell or the another candidate cell, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0012] In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which a CLTM cell switch to the particular candidate cell is triggered based upon a CLTM condition associated with the particular candidate cell being met, determining whether the CLTM cell switch is being triggered before completion of one or more required CLTM cell switch preparation tasks. In some embodiments, the instructions stored on the at least one memory, whenexecuted by the at least one processor, further cause the UE to perform, in an instance in which one or more required CLTM cell switch preparation tasks are incomplete, completing the one or more CLTM cell switch preparation tasks required for CLTM cell switch to the particular candidate cell during the cell switch. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the one or more required CLTM cell switch preparation tasks are complete, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0013] According to another embodiment, a method can be performed, e.g., by a UE, which comprises receiving a Layer 1 / Layer 2 triggered mobility (LTM) configuration associated with one or more candidate cells, wherein the UE is configured to initiate a Conditional LTM (CLTM) cell switch to at least one candidate cell based upon at least one CLTM condition being satisfied. In some embodiments, the method further comprises initiating monitoring of the at least one CLTM condition for CLTM cell switch to the at least one candidate cell or at least one reference signal (RS) configured for the at least one candidate cell. In some embodiments, the method further comprises, based on initiating the monitoring of the at least one CLTM condition for CLTM cell switch, initiating one or more CLTM cell switch preparation actions for the at least one candidate cell or the at least one RS configured for the at least one candidate cell. In some embodiments, the method further comprises, after completion of performance of the one or more CLTM cell switch preparation actions, maintaining the one or more CLTM cell switch preparation actions until a predefined event. In some embodiments, the method further comprises, in an instance in which a cell switch is initiated after completion of performance of the one or more CLTM cell switch preparation actions and before occurrence of a predefined event other than initiation or completion of the cell switch, completing the cell switch within a cell switch delay period that does not comprise one or more cell switch delay subperiods associated with the one or more CLTM cell switch preparation actions.

[0014] According to another embodiment, a UE can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the UE to perform at least, in an instance in which the UE is configured with one or more Conditional Layer 1 / Layer 2 Triggered Mobility (CLTM) conditions for initiating a CLTM cell switch to one or more candidate cells in a mobile network, initiating monitoring for the one or more CLTM conditions for CLTM cell switch associated with the respective cells of the one or more candidate cells. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform initiating CLTM cell switch preparation tasks for the CLTM cell switch to respective candidate cells of the one or more candidate cells. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform determining whether at least one CLTM condition of the one or more CLTM conditions is satisfied, the at least one CLTM condition being conditions for CLTM cell switch to a particular network. In some embodiments, the instructions stored on the at least one memory, whenexecuted by the at least one processor, further cause the UE to perform, in an instance in which the at least one CLTM condition associated with the particular candidate cell is satisfied, determining whether the CLTM cell switch preparation tasks for the CLTM cell switch to the particular candidate cell are complete. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are incomplete, completing the one or more CLTM cell switch preparation tasks during the cell switch. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are complete, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks .

[0015] According to another embodiment, a method can be carried out or performed, e.g., by a UE, that comprises, in an instance in which the UE is configured with one or more Conditional Layer 1 / Layer 2 Triggered Mobility (CLTM) conditions for initiating a CLTM cell switch to one or more candidate cells in a mobile network, initiating monitoring, using the UE, for the one or more CLTM conditions for CLTM cell switch associated with the respective cells of the one or more candidate cells. In some embodiments, the method further comprises initiating, at the UE, CLTM cell switch preparation tasks for the CLTM cell switch to respective candidate cells of the one or more candidate cells. In some embodiments, the method further comprises determining whether at least one CLTM condition of the one or more CLTM conditions is satisfied, the at least one CLTM condition being conditions for CLTM cell switch to a particular network. In some embodiments, the method further comprises, in an instance in which the at least one CLTM condition associated with the particular candidate cell is satisfied, determining whether the CLTM cell switch preparation tasks for the CLTM cell switch to the particular candidate cell are complete. In some embodiments, the method further comprises, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are incomplete, completing the one or more CLTM cell switch preparation tasks during the cell switch. In some embodiments, the method further comprises, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are complete, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0016] According to an embodiment, a device, such as a user equipment (UE) is provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the UE to perform receiving a Layer 1 / Layer 2 triggered mobility (LTM) configuration associated with one or more candidate cells, wherein the UE is configured to initiate a Conditional LTM (CLTM) cell switch to at least one candidate cell based upon at least one CLTM condition being satisfied. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor,further cause the UE to perform initiating monitoring of the at least one CLTM condition for CLTM cell switch to the at least one candidate cell or at least one reference signal (RS) configured for the at least one candidate cell. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, based on initiating the monitoring of the at least one CLTM condition for CLTM cell switch, initiating one or more CLTM cell switch preparation actions for the at least one candidate cell or the at least one RS configured for the at least one candidate cell. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, after completion of performance of the one or more CLTM cell switch preparation actions, maintaining the one or more CLTM cell switch preparation actions until a predefined event. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which a cell switch is initiated after completion of performance of the one or more CLTM cell switch preparation actions and before occurrence of a predefined event other than initiation or completion of the cell switch, completing the cell switch within a cell switch delay period that does not comprise one or more cell switch delay subperiods associated with the one or more CLTM cell switch preparation actions.

[0017] According to another embodiment, a method can be carried out by means, such as a UE comprising a processor and a memory storing instructions thereon. In some embodiments, the method can comprise receiving a Layer 1 / Layer 2 triggered mobility (LTM) configuration associated with one or more candidate cells, wherein the UE is configured to initiate a Conditional LTM (CLTM) cell switch to at least one candidate cell based upon at least one CLTM condition being satisfied. In some embodiments, the method further comprises initiating monitoring of the at least one CLTM condition for CLTM cell switch to the at least one candidate cell or at least one reference signal (RS) configured for the at least one candidate cell. In some embodiments, the method further comprises, based on initiating the monitoring of the at least one CLTM condition for CLTM cell switch, initiating one or more CLTM cell switch preparation actions for the at least one candidate cell or the at least one RS configured for the at least one candidate cell. In some embodiments, the method further comprises, after completion of performance of the one or more CLTM cell switch preparation actions, maintaining the one or more CLTM cell switch preparation actions until a predefined event. In some embodiments, the method further comprises, in an instance in which a cell switch is initiated after completion of performance of the one or more CLTM cell switch preparation actions and before occurrence of a predefined event other than initiation or completion of the cell switch, completing the cell switch within a cell switch delay period that does not comprise one or more cell switch delay subperiods associated with the one or more CLTM cell switch preparation actions.

[0018] According to another embodiment, a UE can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the UE to perform, in an instance in which the UE is configmed with one or more Conditional Layer 1 / Layer 2 Triggered Mobility (CLTM) conditions for initiating a CLTM cell switch to one or more candidate cells in a mobilenetwork, initiating monitoring for the one or more CLTM conditions for CLTM cell switch associated with the respective cells of the one or more candidate cells. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform initiating CLTM cell switch preparation tasks for the CLTM cell switch to respective candidate cells of the one or more candidate cells. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform determining whether at least one CLTM condition of the one or more CLTM conditions is satisfied, the at least one CLTM condition being conditions for CLTM cell switch to a particular network. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the at least one CLTM condition associated with the particular candidate cell is satisfied, determining whether the CLTM cell switch preparation tasks for the CLTM cell switch to the particular candidate cell are complete. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are incomplete, performing one or more incomplete required CLTM cell switch preparation tasks during cell switch. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are complete, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0019] According to another embodiment, a method can be carried out by means, such as a UE, that comprises, in an instance in which the UE is configured with one or more Conditional Layer 1 / Layer 2 Triggered Mobility (CLTM) conditions for initiating a CLTM cell switch to one or more candidate cells in a mobile network, initiating monitoring, using the UE, for the one or more CLTM conditions for CLTM cell switch associated with the respective cells of the one or more candidate cells. In some embodiments, the method can further comprise initiating, at the UE, CLTM cell switch preparation tasks for the CLTM cell switch to respective candidate cells of the one or more candidate cells. In some embodiments, the method can further comprise determining whether at least one CLTM condition of the one or more CLTM conditions is satisfied, the at least one CLTM condition being conditions for CLTM cell switch to a particular network. In some embodiments, the method can further comprise, in an instance in which the at least one CLTM condition associated with the particular candidate cell is satisfied, determining whether the CLTM cell switch preparation tasks for the CLTM cell switch to the particular candidate cell are complete. In some embodiments, the method can further comprise, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are incomplete, performing one or more incomplete required CLTM cell switch preparation tasks during cell switch. In some embodiments, the method can further comprise, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are complete,completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.List of the Drawings

[0020] In the following, the invention will be described in greater detail with reference to the embodiments and the accompanying drawings, in which:

[0021] FIG. 1 illustrates an example of a wireless communications system that supports conditional Layer 1 / Layer 2 triggered mobility (LTM), in accordance with embodiments of the present disclosure;

[0022] FIG. 2 is a signal flow diagram between a user equipment (UE) and an access node (gNB) for initiating and carrying out an example LTM cell switching procedure, in accordance with embodiments of the present disclosure;

[0023] FIG. 3 is a signal flow diagram of an example handover request for a cell switching procedure between a source cell and a target cell, in accordance with embodiments of the present disclosure;

[0024] FIG. 4 illustrates a timeline of cell switching preparation tasks to be carried out during conditional LTM and before cell switching, in accordance with embodiments of the present disclosure;

[0025] FIG. 5 is an example signal flow diagram showing a message sequence and tasks carried out during conditional LTM cell switching, in accordance with embodiments of the present disclosure;

[0026] FIG. 6 is a block diagram of an apparatus that supports conditional LTM cell switching, in accordance with embodiments of the present disclosure;

[0027] FIG. 7 is a process flow diagram of an example process for managing conditional LTM cell switching, in accordance with embodiments of the present disclosure;

[0028] FIG. 8 is a process flow diagram of an example process for managing conditional LTM cell switching, in accordance with embodiments of the present disclosure;

[0029] FIG. 9 is a process flow diagram of an example process for managing conditional LTM cell switching, in accordance with embodiments of the present disclosure;

[0030] FIG. 10 is a process flow diagram of an example process for managing conditional LTM cell switching, in accordance with embodiments of the present disclosure;

[0031] FIG. 11 is a process flow diagram of an example process for managing conditional LTM cell switching, in accordance with embodiments of the present disclosure; and

[0032] FIG. 12 is a process flow diagram of an example process for managing conditional LTM cell switching, in accordance with embodiments of the present disclosure.Abbreviations

[0033] ASN.l Abstract Syntax Notation One

[0034] CHO Conditional Handover

[0035] CLTM Conditional LTM

[0036] CU Centralized Unit

[0037] DL Downlink

[0038] DU Distributed Unit

[0039] gNB gNodeB

[0040] LTM L1 / L2 Triggered Mobility

[0041] PL-RS Path-loss Reference Signal

[0042] RACH Random Access Channel

[0043] RS Reference Signal

[0044] TA Timing Advance

[0045] TRP Transmission / Reception Point

[0046] UE User Equipment

[0047] UL UplinkDetailed Description

[0048] The following embodiments are exemplary. Although the specification may refer to “an”, “one”, or“some” embodiment(s) in several locations of the text, this does not necessarily mean that each reference is made to the same embodiment(s), or that a particular feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments. Further, when a particular feature, structure, or characteristic is described in connection of an embodiment, it is within the knowledge of one skilled in the art to apply such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described. It shall be understood that although the terms “first,” “second” and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another.

[0049] For the purposes of the present disclosure, the phrases “at least one of A or B”, “at least one of A and B”, and “A and / or B” means (A), (B), or (A and B). For the purposes of the present disclosure, the phrase “A, B, and / or C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C).

[0050] Embodiments described may be implemented in a communication network, such as any of the following radio access technologies (RATs): Worldwide Interoperability for Micro-wave Access (WiMAX), Global System for Mobile communications (GSM, 2G), GSM EDGE radio access Network (GERAN), General Packet Radio Service (GRPS), Universal Mobile Telecommunication System (UMTS, 3G) based on basic wideband-code division multiple access (W-CDMA), high-speed packet access (HSPA), Long Term Evolution (LTE), LTE-Advanced, and enhanced LTE (eLTE), 5G (also called NR), or any future RAT such as 6G. Moreover, communication within the communication network may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), TimeDivision Duplex (TDD), Multiple -Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiple (OFDM), and / or Discrete Fourier Transform spread OFDM (DFT-s-OFDM).

[0051] As used herein, the term “network device” or “network node” refers to a node in a communication network via which user equipment may access the network and / or which is capable of controlling radio communication and managing radio resources within a cell. The network node or network device may be referred to as a base station (BS), an access point (AP) or an access node. The network device may be, depending on the applied technology, for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio head (RH), a remote radio head (RRH), a relay, an Integrated Access and Backhaul (IAB) node, a low power node, a non-terrestrial network (NTN) or nonground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, or an aircraft network device.

[0052] Moreover, in connection of split radio access network (RAN), the network device may refer to a centralised unit (CU) of a base station and / or a distributed unit (DU) of a base station. An interface between CU and DU may be referred to as an Fl interface in NR. In the split RAN architecture, node operations may be carried out, at least partly, in the central / centralized unit, CU, (e.g., server, host, or node) operationally coupled to the DU, (e.g. a radio head / node). One CU may control one or more DUs, acting at least as transmit / receive (Tx / Rx) nodes. In some embodiments, the DUs may comprise e.g. a radio link control (RLC), medium access control (MAC) layer and a physical (PHY) layer, whereas the CU may comprise the layers above RLC layer, such as a packet data convergence protocol (PDCP) layer, a radio resource control (RRC) layer, and an internet protocol (IP) layer. Other functional splits are possible too. In practice, any processing task may be performed in either the CU or the DU and the boundary where the responsibility is shifted between the CU and the DU may depend on the applied implementation.

[0053] The term “terminal device” refers to any end device that may be capable of wireless communication.By way of example, a terminal device may be referred to as a communication device, user equipment (UE), a Subscriber Station (SS), or a Mobile Station (MS). The terminal device may include a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, USB dongles, an Internet of Things (loT) device, a watch or other wearable, a headmounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like.

[0054] A term “resource”, as used herein, may refer to radio resources in time domain, in frequency domain, in space domain, and / or in code domain. Some examples of resources include e.g., a physical resourceblock (PRB), a radio frame, a subframe, a time slot, a subband, a frequency region, a sub-carrier, a beam, etc. The term “transmission” and / or “reception” may refer to wirelessly transmitting and / or receiving via a wireless propagation channel on radio resources.

[0055] User equipment (UE) may be configured to carry out connected state mobility, otherwise known as handover procedures, between a currently serving cell (e.g., base station, tower, eNodeB, gNodeB, etc.) of a mobile network, and one or more other cells, known as candidate cells within the mobile network. UEs are logically and operationally organized into lower layers and upper layers. For example, the lower / lowest layer of a UE is the physical layer (PHY), which performs transmission and reception of data over air interface by converting digital data to radio waves and vice versa. A next higher layer of the UE is a medium access control layer (MAC), which manages the shared use of the radio spectrum by allocating resources and ensuring reliable data transmission and reception. A next higher layer of the UE is a radio link control layer (RLC), which provides a reliable data link between the UE and the network (e.g., 5G network) by detecting and correcting errors, segmenting and reassembling data, and controlling flow. A next higher layer of the UE is a packet data convergence protocol layer (PDCP), which encrypts messages for security and compresses headers for efficiency. A next higher layer of the UE is a service data adaptation protocol layer (SDAP), which matches data flows to quality of service (QoS) requirements. A next higher layer of the UE is a radio resource control layer (RRC), which sets up and manages radio bearers. A highest layer of the UE is the non-access stratum layer (NAS), which manages mobility and sessions beyond the radio access network.

[0056] FIG. 1 illustrates an example of a communication network to which examples disclosed herein may be applied. The communication network or a cellular communication network may comprise a network node 110 providing one or more cells, such as cell 100, and a network node 112 providing one or more other cells, such as cell 102. Each cell may be, e.g., a macro cell, a micro cell, femto, or a pico cell, for example. The cell (e.g., 100, 102) may define a coverage area or a service area of the corresponding access node.

[0057] The network node 110 may provide a user equipment (UE) 120 (one or more UEs) with wireless access to the communication network. The wireless access may comprise downlink (DL) communication from the network node to the UE 120 and uplink (UL) communication from the UE 120 to the network node. Examples of uplink channels comprise physical uplink control channel (PUCCH) for transmitting control information and physical uplink shared channel (PUSCH) for transmitting data towards the network. Examples of downlink channels comprise physical downlink control channel (PDCCH) for transmitting control information and physical downlink shared channel (PDSCH) for transmitting data towards the user equipment.

[0058] There may be a plurality of UEs 120, 122 in the system. Each of them may be served by the same or by different network nodes 110, 112. UE may be configured with dual connectivity (DC), wherein the UE, e.g. UE 120, may be connected to multiple network nodes 110, 112. The UEs 120, 122 may communicate with each other, in case device-to-device (D2D) communication interface is established between them via a so-calledsidelink (SL). Such D2D communications may be referred to as machine -to -machine, peer-to-peer (P2P) communications, or vehicle-to-vehicle (V2V), for example.

[0059] In the case of multiple network nodes in the communication network, the network nodes may be connected to each other via an interface. LTE specifications call such an interface as X2 interface. An interface between an LTE node and a 5G node, or between two 5G nodes may be called Xn interface.

[0060] The network nodes 110 and 112 may be further connected via another interface to a core network 116 of the communication network. The LTE specifications specify the core network as an evolved packet core (EPC), and the core network may comprise e.g. a mobility management entity (MME) and a gateway node. The MME may handle mobility of terminal devices in a tracking area encompassing a plurality of cells and handle signalling connections between the terminal devices and the core network. The gateway node may handle data routing in the core network and to / from the terminal devices. The 5G specifications specify the core network as a 5G core (5GC). The 5G core may comprise e.g. an access and mobility management function (AMF) and a user plane function / gateway (UPF) and other functions. The AMF may handle termination of non-access stratum (NAS) signalling, NAS ciphering & integrity protection, registration management, connection management, mobility management, access authentication and authorization, security context management. The UPF node may support packet routing and forwarding, packet inspection and quality of service (QoS) handling, for example.

[0061] In 3 GPP Rel-18, a mobility mechanism was introduced, namely Layer 1 / Layer 2 triggered mobility(LTM), which aims to reduce interruption time during handover.

[0062] The overall procedure for LTM is illustrated in the signaling diagram in FIG. 2, with reference to the network components schematically illustrated in FIG. 1. FIG. 2 is taken from Figure 9.2.3.5.2-1 of 3GPP Technical Specification Document No. 38.300, version 18, the entire disclosure of which is incorporated herein by reference in its entirety for all purposes as if reproduced completely herein. As described in 3GPP TS 38.300 v.18, at section 9.2.3.5.2, the procedure for LTM comprises:

[0063] In Step 1 of FIG. 2 the UE, for example, the UE 120 sends a MeasurementReport message to the gNB 110, which provides access to the source cell 100. The gNB 110 decides to configure LTM and initiates LTM preparation.

[0064] In Step 2 of FIG. 2, the gNB 110 transmits an RRCReconfiguration message to the UE 120 including the LTM candidate configurations.

[0065] In Step 3 of FIG. 2 the UE 120 stores the LTM candidate configurations and transmits an RRCReconfigurationComplete message to the gNB 110.

[0066] In Step 4a of FIG. 2, the UE 120 performs DL synchronization with the candidate cell(s) 102 before receiving the cell switch command.

[0067] In Step 4b of FIG. 2, when the UE-based TA measurement is configured, the UE 120 acquires the TA value(s) of the candidate cell(s) 102 by measurement. The UE 120 performs early TA acquisition with thecandidate cell(s) 102 as requested by the network before receiving the cell switch command as specified in clause 9.2.6. This is done via CFRA triggered by a PDCCH order from the source cell 100, following which the UE 120 sends preamble towards the indicated candidate cell 102. In order to minimize the data interruption of the source cell 100 due to CFRA towards the candidate cell(s) 102, the UE 120 does not receive a random access response from the network for the purpose of TA value acquisition and the TA value of the candidate cell 102 is instead indicated in the cell switch command. The UE 120 does not maintain the TA timer for the candidate cell 102 and relies on network implementation to guarantee the TA validity.

[0068] In Step 5 of FIG. 2 the UE 120 performs LI measurements on the configured candidate cell(s) 102 and transmits LI measurement reports to the source gNB 110.

[0069] In Step 6 of FIG. 2, the gNB 110 decides to execute a cell switch from the source cell 100 to the candidate or target cell 102 and transmits a MAC CE triggering cell switch by including the candidate configuration index of the target cell 102. The UE 120 then switches to the target cell 102 and applies the configuration indicated by candidate configuration index.

[0070] In Step 7 of FIG. 2 the UE 120 performs the random access procedure towards the target cell 102, if the UE 120 does not have a valid TA of the target cell 102 as specified in clause 6.1.3.xy of TS 38.321.

[0071] In Step 8 of FIG. 2, the UE 120 completes the LTM cell switch procedure by sending RRCReconfigurationComplete message to the gNB 112 providing access to the target cell 102.

[0072] If the UE 120 has performed a RA procedure in Step 7 of FIG. 2 then the UE 120 considers that LTM cell switch execution is successfully completed when the random access procedure is successfully completed.

[0073] For RACH-less LTM, the UE 120 considers that the LTM cell switch execution is successfully completed when the UE 120 determines that the network has successfully received its first UL data.

[0074] As seen above, in LTM, early TA acquisition, i.e., TA acquisition before handover / cell switch, can be performed in the following ways:

[0075] Firstly, the network can order the UE 120 to perform random access (RA) preamble transmission to a candidate cell 102. The candidate cell 102 uses the received RA preamble to estimate the TA and provides the TA estimate to the source cell 100. When the source cell 100 decides to trigger the cell switch, it provides the estimated TA value along with the cell switch command.

[0076] Secondly, during LTM preparation, the network can configure the UE 120 to perform UE-based TA measurements. UE-based TA measurements may be performed based on the TA of the serving cell 100 and the measured time difference between the candidate cell 102 and the serving cell 100. After being configured, the UE 120 is assumed to obtain a TA measurement before a cell switch command is issued by the gNB 110 providing access to the source cell 100.

[0077] Another purpose served by random access is that the target gNB 112 is notified about the presence of the UE 120 and resources for the UE’s subsequent transmissions are provided to the UE 120. Hence, whenRACH-less LTM cell switch is performed, a mechanism is required to support the initial transmission of the UE 120 to the target cell 102. A mechanism that supports this purpose is the provisioning of configmed grants, which consist of sets of resources in the candidate / target cell that the UE 120 may use if / when it performs its initial transmission after handover / cell switch to the target cell 102. An alternative to this mechanism is to provide an access notification from the source cell 100 to the target cell 102, so that the target cell 102 can then provide a dynamic grant to the UE 120 for the target cell 102.

[0078] A similar RACH-less approach has also been proposed for baseline and conditional handover (BHO / CHO) as well to facilitate fast cell switch.

[0079] According to some embodiments, a UE can be configured to perform Layer 1 / Layer 2 Triggered Mobility (LTM), e.g., with measurements being performed by PHY layer and monitoring / triggering by MAC layer. The LTM procedure can involve cell change from a serving cell to a candidate cell that is triggered by the serving distributed unit (DU) based on PHY layer beam measurements performed by the UE of one or more candidate cells reported by the UE to the serving DU at least for multibeam deployments.

[0080] Referring now to FIG. 3, a handover (HO) procedure is illustrated in which a UE 220 is caused to cell switch from a source gNB 210 to a target gNB 212. As illustrated, the source gNB 210 can provide a HANDOVER REQUEST message to the target gNB 212, which can perform an admission control procedure to determine if HO is appropriate for the UE 220.

[0081] If appropriate, the target gNB 212 provides a HANDOVER REQUEST ACKNOWLEDGE message to the source gNB 210. The source gNB 210 can then transmit an RRCReconfiguration message to the UE 220.

[0082] Upon receiving the RRCReconfiguration message at the UE 220 from the source gNB 210, the UE 220 can be caused to switch to the target gNB 212 and subsequently send an RRCReconfigurationComplete message to the target gNB 212.

[0083] HO procedures, such as that illustrated in FIG. 3, are network-led and often based on network congestion, network-side measurements, or conventional periodic measurement reporting by the UE 220.

[0084] Some wireless devices, such as UE 120 or UE 220 may be configured to carry out connected state mobility, otherwise known as handover procedures, between the gNB 210 in a currently serving cell of a mobile network, and one or more other cells, known as candidate cells (e.g., 212) within the mobile network. A UE can be configured (e.g., by the network) with a list of configmed candidate cells which are candidate cells for a cell switch or handover procedure (e.g., possible cells on which the UE can switch / hand over and which can provide services to the UE). As used herein, the term ‘handover’ generally refers to an L3 triggered handover and the term ‘cell switch’ generally refers to a Layer 1 / Layer 2 Triggered Mobility (LTM).

[0085] A UE (e.g., 120, 220) typically reports out to the network on cell-level signal or service quality to the network, or the cell can provide to the network or UE regular reports on cell quality for a particular cell.When cell quality for a currently serving cell becomes diminished, handover between the currently serving cell and another cell can be carried out to improve continuity and quality of service. While a particular cell may be involved in beam-level mobility within that particular cell, the UE or an element or function at the mobile network is typically involved in cell-level mobility.

[0086] Typically, the UE would monitor cell quality, identify when a quality characteristic of the serving cell becomes sufficiently diminished to trigger a handover, sample one or more candidate cells to determine if the cell quality will be increased by switching to that particular other cell, and the UE sends a request to the mobile network for a handover from the serving cell to that particular candidate cell.

[0087] However, the evaluation by the UE (e.g., 120, 220) of candidate cells takes time and consumes computational resources, while signaling between the UE and the mobile network consumes network resources. In order to reduce the signaling and other resource use prior to initiation of a handover procedure, in some cases, a UE may be configured (e.g., pre-configured) by the mobile network for a conditional handover procedure based on one or more signal threshold conditions for one or more candidate cells. Thereafter, if the UE determines a candidate cell has satisfied the signal threshold conditions that the mobile network configured at the UE, the UE can execute a conditional handover procedure to the candidate cell that the UE determined has satisfied the signal threshold conditions. Conditional handover may be carried out at the UE using LTM. Conditional handover via LTM may be referred to as conditional LTM (CLTM).

[0088] Before a UE (e.g., 120, 220) performs or participates in any cell switching under LTM / CLTM, the UE typically provides one or more measurements to the network. For example, the UE can provide a Measurement Report message or the like to the serving cell (e.g., serving gNB). In some embodiments, the serving ccll / gNB can decide to send a request to another network element (e.g., AMF, UPF, AUSF, UDM, SMSF, etc.) to confirm the need for the UE to be configured for LTM / CLTM. In other embodiments, the serving cell / gNB can decide itself whether there is a need for the UE to be configured for LTM / CLTM. This determination about whether the UE needs to be configured for LTM / CLTM can be based upon a signal strength, a signal quality, a signal characteristic, or the like of an RS at the serving beam in the serving cell being sufficiently low or indicating an undesirable change over time, such as a drop in signal strength that might be associated with the UE moving away from the serving cell.

[0089] In an instance in which the serving cell / gNB decides to configure LTM / CLTM, it prepares a number of different candidate cells (e.g., up to about 8). The serving cell / gNB may then send a message, such as an RRCReconfiguration message, to the UE (e.g., 120, 220) with the LTM / CLTM candidate cell configurations. The UE then stores the LTM / CLTM candidate cell configurations. In some instances, the UE may send, to the serving cell / gNB, a message confirming completion of reconfiguration of the UE for the LTM / CLTM candidate cells, such as by sending an RRCReconfigurationComplete message to the serving ccll / gN B.

[0090] Candidate cells are typically neighboring cells to the serving cell (also referred to as the ‘source cell’), and in LTM they may also be some of UE’s current serving cells such as SCells. Under Rel. 19 of the3GPP standard for NR, it is expected that the network will pre-configure a standard-compliant UE for LTM / CLTM to one or more respective candidate beams in up to eight different candidate cells. It may be expected, e.g., during the RRC Reconfiguration process to enable the UE to be configured for LTM / CLTM, that the UE performs a number of LTM / CLTM cell switch preparation tasks for each candidate beam in each candidate cell. In other embodiments, the UE may be expected to perform only a subset of the LTM / CLTM cell switch preparation tasks for each candidate beam in each candidate cell or for less than all candidate beams in each candidate cell.

[0091] Such LTM / CLTM cell switch preparation tasks can include: downlink and uplink synchronization, LTM candidate cell configuration processing, Abstract Syntax Notation One (ASN.l) decoding and validity check, and path loss estimation. These can be referred to, respectively, as LTM / CLTM cell switch preparation Task 1, LTM / CLTM cell switch preparation Task 2, LTM / CLTM cell switch preparation Task 3, and LTM / CLTM cell switch preparation Task 4. However, the numerals and / or listing order of these tasks does not indicate any required order of these tasks, does not indicate any dependency of any task on the other tasks, such as on the completion of one or more other tasks, and does not indicate any timing or duration of these tasks. Also, some or all of these tasks may not be required for a UE (e.g., 120, 220) depending on the network, network type, communication type, implementation details, UE type, and / or for other reasons. Further, some UEs may not be capable of performing some or all of these tasks.

[0092] However, UEs (e.g., 120, 220) are typically not configured for and / or capable of carrying out some or all of the tasks related to preparing for LTM / CLTM cell switching and other conditional handover events for (often) a plurality of different candidate beams for a large number (e.g., more than two or three) of candidate cells for which the UE is configured for CLTM. This may be because of the computational complexity and / or signaling / resource use intensiveness of performing these tasks, because of an allotted duration during which the UE is to complete these tasks is insufficiently short, and / or because the UE cannot perform all or certain of these tasks in parallel, among other such reasons.

[0093] That being said, many UEs (e.g., 120, 220) will be preconfigured with candidate cell configurations for one or more candidate cells, reference signals (RS) associated with the candidate cells, etc. Additionally, UEs may be configured for one or more conditions associated to those candidate cells or RS, to trigger conditional LTM cell switch. The UE starting to evaluate one or more CLTM cell switch conditions for one or more of the candidate cell configurations for the candidate cells may trigger the UE to perform one or more LTM / CLTM cell switch preparation tasks in order for the UE to be prepared for LTM or CLTM cell switching processes in the event that the UE receives an LTM cell switch command from the network or a condition for CLTM cell switch becomes met, in the course of ongoing monitoring of the candidate cells as part of preparing for LTM / CLTM cell switching from a currently serving cell to a candidate cell in response to a CLTM-triggering event or condition by one of the candidate cells (or a beam / RS thereof).

[0094] In some instances, the network may understand or expect that the UE (e.g., 120, 220) will take a certain duration to complete one or more of LTM / CLTM cell switch preparation tasks after initiating the performance of these tasks. This preparation duration may be the total duration during which the UE is to conduct the LTM / CLTM cell switch preparation tasks. After the expiration of this LTM / CLTM preparation duration, the UE can be required to maintain the already conducted LTM / CLTM cell switch preparation tasks for a certain maintenance period or duration. After the expiration of this maintenance period or duration, the UE can discontinue performing the LTM / CLTM cell switch preparation tasks. In other instances, the network may communicate to the UE, e.g., with the candidate cell configurations, a certain LTM / CLTM maintenance duration. In still other instances, the UE may indicate to the network a desired or required LTM / CLTM preparation and / or maintenance duration, which, in some instances, the network can accept or reject.

[0095] During the LTM / CLTM preparation duration, the UE (e.g., 120, 220) will perform the LTM / CLTM cell switch preparation tasks and during the LTM / CLTM maintenance duration, the UE will maintain the LTM / CLTM cell switch preparation tasks. During the preparation and maintenance durations, the UE will also monitor one or more of the candidate cells for which the network provided the candidate cell configurations to determine if a candidate beam at any candidate cell satisfies a CLTM condition threshold that causes the UE to initiate CLTM. In the event of the CLTM condition being satisfied, the UE automatically initiates a CLTM cell switch procedure to the candidate cell (which can now be referred to as a ‘target cell’.

[0096] As noted above, during the LTM / CLTM preparation duration, the UE (e.g., 120, 220) performs the LTM / CLTM cell switch preparation tasks, which can include the UE tracking fine downlink tuning and frequency synchronization for the candidate cell and maintains these steps during the maintenance duration followed by the preparation duration. The UE can also do this for one or more other candidate cells, or it may perform this step for just the particular candidate cell it expects to switch to from the currently serving cell. During the LTM / CLTM preparation duration, the UE can also or alternatively perform early ASN.1 decoding and validity check and store the decoded configuration of the candidate cell throughout the maintenance duration. During the LTM / CLTM preparation duration, the UE can also or alternatively perform path loss estimation of RS (PL-RS) in the candidate cells the UE is currently evaluating, and maintain the PL-RS at the UE, and update the PL-RS estimates for the candidate cells as needed throughout the LTM / CLTM maintenance duration. During the LTM / CLTM preparation duration, the UE can also or alternatively acquire timing advance (TA) information (or determine / estimate the validity of available TA information, if available) for candidate cells the UE is currently evaluating and maintain a valid TA for each candidate cell during the LTM / CLTM measurement duration by updating the TA acquisition or TA validity evaluation as needed during the maintenance duration. TA acquisition or available TA validation for candidate cells can be performed by the UE based on a configuration of UE-based TA estimation for the candidate cell or a RACH-based TA acquisition procedure. In some instances, the configuration of the UE-based TA estimation for the candidate cell by the UE can be performed by the UE estimating the TA if a valid TA is not available based on earlier RACH-based TAacquisition or UE based TA estimation or RRC configuration. The UE will keep track of and re-estimate, if needed, the estimated UE-based TA value for each candidate cell throughout the LTM / CLTM maintenance duration. On the other hand, the RACH -based TA acquired by the UE can be initially evaluated to determine the validity of a RACH-based TA (if available) based on, e.g., measurements and / or time alignment timer (TAT) expiry, and subsequently if the UE determines the RACH-based TA acquired by the UE is invalid, the UE can request a new RACH preamble from the network in order for the UE to acquire therefrom a fresh RACH-based TA estimate.

[0097] One issue identified in advance of the completion of Rel. 19 of the 3 GPP NR standards is that many UEs (e.g., 120, 220) will be unable to perform all of the LTM / CLTM cell switch preparation tasks for all candidate beams in all candidate cells prior to either the UE receiving an LTM cell switch command message from the network or a quality / characteristic of one of the candidate beams in one of the candidate cells satisfying a CLTM threshold that triggers the CLTM procedure in the UE. In such instances, the UE will still be performing measurements completing tasks from among the LTM / CLTM cell switch preparation tasks for many if not all candidate beams in many if not all candidate cells. When the network (e.g., serving cell / gNB) provides LTM / CLTM configurations for candidate cells to the UE, the network understands and accounts for a certain preparation delay associated with the UE performing the LTM / CLTM cell switch preparation tasks.

[0098] Thereafter, if the network (e.g., serving cell / gNB) provides an LTM cell switch command message or the like to the UE (e.g., 120, 220) after that certain preparation duration and during the certain maintenance duration, the UE does not need to take additional time to complete the LTM / CLTM cell switch preparation tasks for the indicated candidate cell or beam at the particular candidate cell (i.e., target cell) indicated in the LTM cell switch command message during the cell switch. As such, after the sending of the LTM cell switch command message to the UE during such maintenance duration occurring after preparation duration, the network will understand that the UE may not need time to complete the LTM / CLTM cell switch preparation tasks for the indicated candidate cell / beam during the completion of the LTM / CLTM cell switch, and hence the network may expect a shorter cell switch delay.

[0099] Alternatively, the network will also understand and expect that the UE (e.g., 120, 220), if the UE had not completed the LTM / CLTM cell switch preparation tasks for the indicated candidate beam in the particular candidate cell at the time the UE received the LTM / CLTM cell switch command message from the network, the UE will need to take additional time to complete the LTM / CLTM cell switch preparation tasks for the indicated candidate beam, and will account for an additional expected delay associated therewith. As such, after the sending of the LTM cell switch command message to the UE during such preparation duration, the network will understand that the UE may need time to complete the LTM / CLTM cell switch preparation tasks for the indicated candidate cell / beam during the completion of the LTM / CLTM cell switch, and hence the network may expect a longer cell switch delay

[0100] Alternatively, in some instances, the UE (e.g., 120, 220) may not receive, during a period of time when the UE is performing the LTM / CLTM cell switch preparation tasks, a LTM cell switch command message or the like from the network that triggers an LTM cell switch procedure from the serving cell to a particular candidate cell. In that instance, the UE will not be externally triggered to switch from the source cell / serving cell to a candidate cell under an LTM procedure. However, during this period of time when the UE is performing the LTM / CLTM cell switch preparation tasks, the UE is still configured or being configured to monitor signal qualities / characteristics of candidate beams in the candidate cells to determine if any trigger a CLTM procedure, in which the UE performs a conditional cell switch procedure (CLTM) from the serving cell to a particular candidate cell that triggered the CLTM procedure without waiting for a cell switch command or the like from the network.

[0101] If a candidate cell for which the UE (e.g., 120, 220) is configured for CLTM triggers a CLTM procedure, e.g., based on a signal strength of a candidate beam being stronger than the signal strength of the serving beam in the serving cell or based on a signal strength of a candidate beam being greater than a signal strength offset stronger than the signal strength of the serving beam in the serving cell, the UE will be required to perform the CLTM procedure for handover to that particular candidate cell. However, if the UE has not completed the LTM / CLTM cell switch preparation tasks for the particular candidate cell or for the candidate beam at the particular candidate cell, the UE may need more time for completion of the CLTM procedure as required in order to complete the LTM / CLTM cell switch preparation tasks for the particular candidate cell or candidate beam at the particular candidate cell.

[0102] Since the network is not likely aware of the time at which the CLTM triggering condition became satisfied, the network may not need to be alerted by the UE about an additional UE-side delay in performing the CLTM procedure for cell switch to the particular candidate cell. However, in those instances, as in the LTM procedure described above, the network will understand that the UE should complete the LTM / CLTM cell switch preparation tasks for at least the candidate cell before the UE initiates a RACH-based CLTM handover or RACH- less CLTM handover, depending on whether the UE has updated and validated TA information for the candidate cell. The network will therefore understand that an additional delay associated with the completion of the LTM / CLTM cell switch preparation tasks by the UE is expected if the condition for CLTM becomes satisfied within the preparation duration after the UE started the CLTM evaluation. The network will also understand that no additional delay associated with the completion of the LTM / CLTM cell switch preparation tasks by the UE is expected in the cell switch delay if the condition for CLTM becomes satisfied within the maintenance duration after the UE started the CLTM evaluation.

[0103] In some embodiments, a UE (e.g., 120, 220) can be configured / triggered to start CLTM evaluation for one or more of the configured LTM candidate cells or some RS for a candidate cell. In some embodiments, the UE may be required to perform one or more LTM / CLTM cell switch preparation tasks. Performing each ofthese tasks / steps takes up some time. One or more of these LTM / CLTM cell switch preparation tasks may be performed in parallel or sequentially, or as a combination of these.

[0104] Once the UE (e.g., 120, 220) has completed performing one or more of the LTM / CLTM cell switch preparation tasks, and cell switch happens after this based on the condition for CLTM being met or based on a cell switch command (which may still be an option even if CLTM is configured). In some embodiments, the UE may not be given additional time or may not take additional time for the one or more LTM / CLTM cell switch preparation tasks during the cell switch. If the cell switch happens before the UE has completed one or more of the LTM / CLTM cell switch preparation tasks, the UE can be given additional time or may take additional time to complete the one or more LTM / CLTM cell switch preparation tasks during the cell switch.

[0105] Referring now to FIG. 4, a timeline for LTM / CLTM cell switch preparation tasks for cell switch associated with LTM / CLTM condition evaluation is illustrated. In the illustration, the left (darker) fifth of the horizontal block represents the time during which the UE is performing one or more LTM / CLTM cell switch preparation tasks. In some embodiments, after the UE has performed these steps, the right (lighter) fourth fifths of the horizontal block represents the time during which UE shall maintain the preparation step in question (in this example until the UE is configured to stop CLTM evaluation).

[0106] If cell switch is triggered based on a trigger event being satisfied or a condition being met, or if a cell switch command is received while the UE is still performing one or more of the LTM / CLTM cell switch preparation tasks (Option 1), the cell switch delay is longer and may comprise time for one or more of the LTM / CLTM cell switch preparation tasks. If the cell switch is triggered after the UE has performed the LTM / CLTM cell switch preparation tasks (Option 2), the UE is not given time to perform or does not take additional time to perform the LTM / CLTM cell switch preparation tasks during the cell switch, and hence the cell switch is shorter (i.e., takes less time).

[0107] According to some embodiments, the left (darker) fifth of the horizontal block in FIG. 4, which may represent the delay for a UE (e.g., 120, 220) to perform the LTM / CLTM cell switch preparation tasks, may be defined as:

[0108] Step 1: DL synchronization delay, which may be for example time until the first RS (e.g. SSB or TRS) after condition evaluation is triggered plus the time for RS (e.g., SSB or TRS) processing.

[0109] Step 2: ASN.l decoding and validity check delay, which may be for example 10 ms from the time condition evaluation is triggered.

[0110] Step 3 : PL-RS estimation delay, which may be for example defined as a number of PL-RS periods, where the number of periods may correspond to the number of needed PL-RS measurement samples.

[0111] Step 4: Delay for UE based TA estimation, which may be defined as a number of RS periods for the RS that is used for UE based TA estimation (for instance SSB or CSI-RS based, or specific RS for TA estimation. OR delay for RACH based TA acquisition procedure.

[0112] If the UE is not able to perform any of the LTM / CLTM cell switch preparation tasks (e.g., steps 1- 4) in parallel, the delay would be the sum of the delays for each LTM / CLTM cell switch preparation tasks the UE is required to perform.

[0113] In some cases, the UE (e.g., 120, 220) may be able to perform at least two of the LTM / CLTM cell switch preparation tasks in parallel. This may be indicated via capability signalling.

[0114] If the UE is able to perform all of the LTM / CLTM cell switch preparation tasks (e.g., all of steps 1-4) in parallel, the delay associated with cell switch may be defined as the maximum delay from among the delays associated with each LTM / CLTM cell switch preparation tasks.

[0115] If the UE is able to perform some of the LTM / CLTM cell switch preparation tasks (e.g., some of steps 1-4) in parallel and some of the LTM / CLTM cell switch preparation tasks sequentially, the delay estimated for or associated with cell switch may be a sum of a maximum delay from among the LTM / CLTM cell switch preparation tasks that can be performed in parallel and each of the delays estimated for or associated with each of the LTM / CLTM cell switch preparation tasks that must be performed sequentially.

[0116] For steps 1-3 from among the LTM / CLTM cell switch preparation tasks, if the UE has performed the step before cell switch, the UE is not given additional time or does not take additional time to perform the LTM / CLTM cell switch preparation tasks during the cell switch.

[0117] For step 4 of the LTM / CLTM cell switch preparation tasks, if the UE has performed UE based TA or RACH-based TA estimation at the time of cell switch, the UE can be required to or able to perform a RACH- less cell switch.

[0118] Referring now to FIG. 5, an example signaling flow is illustrated for CLTM candidate cell configuration and CLTM. In some embodiments, the performance of LTM / CLTM cell switch preparation tasks in the signaling diagram are for a case in which a UE 420 has sufficient time before the commencement of the cell switch procedure to perform all of the LTM / CLTM cell switch preparation tasks (e.g., steps 1-4) and maintain the steps performed.

[0119] In the signaling flow of FIG. 5, the network may configure the UE 420 to perform one or more LTM / CLTM cell switch preparation tasks (for a predefined time period) at the time when CLTM is activated. This step may be optional. The network may configure the UE 420 to perform the LTM / CLTM cell switch preparation tasks by a source Transmission and Reception Point (sTRP) 410 providing a CLTM candidate cell preparation message, at 312, to the UE 420. At 314, the UE 420 can be triggered to start condition evaluation for a target TRP 412, referred to in FIG. 5 as a tTRP 1 condition 1 evaluation.

[0120] After the condition evaluation is triggered at 314 and before the condition becomes met at 326, the UE 420 performs and maintains one or more of the LTM / CLTM cell switch preparation tasks. Several nonlimiting examples of LTM / CLTM cell switch preparation tasks are described below. In some embodiments, some of these LTM / CLTM cell switch preparation tasks may not be required for the UE 420 to complete before or during cell switch, depending on, e.g., the capabilities of the UE 420 and / or mobile network requirements orarchitecture. In other embodiments, all of the LTM / CLTM cell switch preparation tasks are required for the UE 420 to complete before or during cell switch, depending on, e.g., the capabilities of the UE 420 and / or mobile network requirements or architecture. In still other embodiments, other LTM / CLTM cell switch preparation tasks in addition to or instead of one or more of the LTM / CLTM cell switch preparation tasks described below may be required for the UE 420 to complete before or during cell switch, depending on, e.g., the capabilities of the UE 420 and / or mobile network requirements or architecture.

[0121] At 318, the UE 420 can perform ASN.l decoding and validity check to tTRP 1 configuration. At 320, the UE 420 can perform PL-RS estimation for the RS for tTRP 1. At 322, the UE 420 can acquire TA for tTRP 1 based on RACH or measurements. At 324, the UE 420 can maintain pre-LTM steps including, e.g., 318, 320, 344, etc.

[0122] Based on performance and maintenance of the TA acquisition step at 322 before the condition becomes met at 326, UE 420 can perform a RACH-less cell switch at 328.

[0123] In some embodiments, if only some of the LTM / CLTM cell switch preparation tasks (e.g., 318, 320, 322) are required to be performed by the UE 420 when condition evaluation is active, the cell switch delay is impacted only by the steps that are required to be performed.

[0124] Which of the steps 1-4 the UE 420 shall perform may be defined directly in the specification or they may be specified to be a UE capability.

[0125] In some embodiments, additional network signaling is introduced to tell the UE 420 which of steps 1-4 it shall perform at the time the condition evaluation starts. Such signaling can be given directly in the LTM RRC configuration or it may be signaled in some existing or new signal such as MAC-CE.

[0126] In some embodiments, the UE 420 can be configured with one or more LTM candidate cells, and for one or more of those candidate cells, the network configures one or more conditions for conditional LTM cell switch. When such condition becomes fulfilled based on UE measurements, the UE 420 will execute a conditional cell switch to the candidate cell / beam in question without a cell switch command.

[0127] In some embodiments, conditional LTM cell switch delay can be defined as the time between the moment the UE 420 starts to evaluate the CLTM condition, and the moment at which the UE 420 completes the conditional cell switch.

[0128] In some embodiments, an example for the CLTM delay formula can be:DcLTM= TLTM_event_DU+TLTM_measure+ TLTM-RRC-processing+ TLTM-processing+ Tfirst-RS+TRS-proc+ TLTM-IU, whereTLTMEvent u is the uncertainty time from when the UE starts to evaluate the CLTM condition until the time the condition for CLTM becomes met;T measure is the time from the end of TLTM _Event_DU that is allowed for the UE to realize the condition is met before the UE is required to start CLTM execution; 1T TM-RRC-processing is the time for ASN.l decoding and validity check. TLTM-RRC-processing equals to zero if the UE has performed ASN.1 decoding and validity check prior to conditional cell switch execution;Tfirst-RS is the time until the first RS (SSB) to be used for downlink synchronization. Tf1Ist-RS equals to zero if the UE has performed downlink synchronization prior to conditional cell switch execution;TRS-PTOC is the RS (SSB) processing time and TRS-PTOC equals to zero if the UE has performed downlink synchronization prior to conditional cell switch execution; andTLTM-IU is the uncertainty time until the preamble transmission on the target cell in RACH-based CLTM cell switch, and time until the first uplink transmission in RACH-less CLTM cell switch.

[0129] In some embodiments, a starting point of the CLTM cell switch may be the time at which the UE 420 starts the CLTM condition evaluation. This starting point may depend on when the CLTM condition evaluation is considered active. In some embodiments, the ending point of conditional cell switch can be the time at which the UE 420 sends either RACH preamble (RACH-based cell switch) or first UL transmission (RACH-less cell switch) on the target cell. In some embodiments, the ending point of CLTM cell switch is the first UL transmission (RACH-based or RACH-less).

[0130] In some embodiments, some of the LTM / CLTM cell switch preparation tasks can be performed in parallel. In some embodiments, some of the LTM / CLTM cell switch preparation tasks can be performed in series. In some embodiments, only a portion of the LTM / CLTM cell switch preparation tasks can / must / need be completed. In some embodiments, if and / or when the LTM / CLTM cell switch preparation tasks are performed at the time of LTM / CLTM cell switch, may be a factor of expected LTM / CLTM cell switch performance and which tasks may be required or helpful when performing LTM / CLTM cell switch. In some embodiments, certain LTM / CLTM cell switch preparation tasks (e.g., UL and DL synchronization) may be necessary to complete prior to LTM / CLTM cell switch. In some embodiments, certain LTM / CLTM cell switch preparation tasks (e.g., PL- RS estimation and ASN.1 decoding and validity check) may be helpful but unnecessary to complete prior to LTM / CLTM cell switch. In other embodiments, some of these and / or other LTM / CLTM cell switch preparation tasks, such as those described elsewhere in this disclosure and / or the like, can be required tasks or unrequired tasks. This may depend, e.g., on the network, UE, CLTM trigger, and / or the like.

[0131] In some embodiments, certain LTM / CLTM cell switch preparation tasks may be necessary to complete prior to initiation of LTM / CLTM cell switch, while other LTM / CLTM cell switch preparation tasks may be completed after initiation of LTM / CLTM cell switch but prior to completion of LTM / CLTM cell switch. This difference between LTM / CLTM cell switch preparation tasks, e.g., in terms of when they are required to be completed and whether the UE and network account or allow for completion of these tasks, can affect the delay budget or allowed / expected time that is taken to perform LTM cell switch or CLTM cell switch. Saidotherwise, if required LTM / CLTM cell switch preparation tasks are incomplete at the time of triggering CLTM cell switch or upon receiving an LTM cell switch command, the UE performs one or more remaining required LTM / CLTM cell switch preparation tasks during cell switch. On the other hand, if all required LTM / CLTM cell switch preparation tasks are complete at the time of triggering CLTM cell switch or upon receiving an LTM cell switch command, the UE proceeds directly with performing an initial transmission (e.g., a RACH preamble or the like) without performing one or more of the LTM / CLTM cell switch preparation tasks during cell switch.

[0132] In some embodiments, CLTM cell switch delay requirements for conditional PCell switch cover also subsequent conditional PSCell switch. In some embodiments, the expected / allowed delay budget for an initial LTM / CLTM cell switch may be different than the expected / allowed delay budget for subsequent LTM / CLTM cell switch(es).

[0133] In some embodiments, early TCI state activation and PDCCH ordered RACH delay can be affected by changes to the LTM / CLTM cell switch delay budget. In some embodiments, additional LTM / CLTM cell switch requirements may be required due to enhanced CLTM specific DL / UL sync procedures for CLTM.

[0134] Some or all of the processes, methods, and tasks, such as signaling, performing measurements, configuring hardware, generating measurement reporting, transmission / reception of signaling, and / or the like, can be carried out using an apparatus that is or comprises a computing device or a computer-based device.

[0135] FIG. 6 shows, by way of example, a block diagram of an apparatus 500. The apparatus 500 comprises, for example, at least one processor 512 and at least one memory 514 storing instructions 515 that, when executed by the at least one processor, cause the apparatus 500 at least to perform the method or methods as disclosed herein, and any of the embodiments thereof. In an example, the at least one memory and the instructions (e.g., a computer program code, software), are configured, with the at least one processor, to cause the apparatus 500 to perform the method or methods as disclosed herein, and any of the embodiments thereof.

[0136] A processor 512 may comprise circuitry, or be constituted as circuitry or circuitries, the circuitry or circuitries being configured to perform phases of methods in accordance with example embodiments described herein. As used in this application, the term “circuitry” may refer to one or more or all of the following: (a) hardware-only circuit implementations, such as implementations in only analog and / or digital circuitry, and (b) combinations of hardware circuits and software, such as, as applicable: (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and (ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a user equipment (e.g., 120), to perform various functions) and (c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation. This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / orfirmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0137] The memory 514 may be implemented using any suitable data storage technology. The memory may comprise a database for storing data. The memory 514 may be at least in part external to the apparatus 500 but accessible to the apparatus 500.

[0138] The instructions 515 may be comprised in a computer readable medium or a non-transitory computer readable medium. A term non-transitory, as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., random access memory [RAM] vs. read only memory [ROM]).

[0139] For example, in some embodiments, the apparatus 500 is a terminal device, such as UE 120 in FIG. 1. As another example, the apparatus is comprised in such a terminal device, e.g. as a chipset configmed to control the terminal device. The apparatus 500 may be caused or configmed to perform a method according to any one or more of the embodiments described.

[0140] As another example, the apparatus 500 is a network node, e.g., 110 in FIG. 1. In another embodiment, the apparatus 500 is comprised in such a network node, e.g. as a chipset configured to control the network node. The apparatus 500 may be caused or configmed to perform a method according to any one or more of the embodiments described.

[0141] The apparatus 500 may comprise one or more entities of any of protocol layers, such as a MAC entity, an RRC entity, an RLC entity, a PDCP entity or a PHY entity. In some embodiments, the entity is configmed to perform one or more of the various described methods or elements / steps thereof, in accordance with one or more of the embodiments described.

[0142] The apparatus 500 comprises a radio interface 516. The radio interface 516 may provide the apparatus 500 with communication capabilities. The radio interface 516 may comprise a receiver configured to receive information in accordance with at least one cellular or non-cellular standard. The radio interface 516 may comprise a transmitter configmed to transmit information in accordance with at least one cellular or non- cellular standard. The receiver may comprise more than one receiver. The transmitter may comprise more than one transmitter. The radio interface 516 may comprise a transceiver configmed to receive and transmit information in accordance with at least one cellular or non-cellular standard. The transceiver may comprise more than one transceiver.

[0143] The apparatus 500 may comprise a user interface 518 comprising, for example, at least one of a keypad, a microphone, a touch display, a display, a speaker, etc. The user interface 518 may be used to control the apparatus by the user. The user interface 518 may be external to the apparatus 500. For example, the apparatus 500 may be connected to another device, such as a computer, either via wireless or wired connection, and the apparatus 500 is controlled by the user via the computer.

[0144] In an embodiment, at least some of the processes described herein may be carried out by an apparatus comprising means for carrying out at least some of the described processes. Means for performing method steps as disclosed herein may include software and / or hardware components of the apparatus 500. For example, the at least one processor 512, the memory 514, and the computer program code form means for carrying out the method or methods as disclosed herein, and any of the embodiments thereof. As used herein the term “means” is to be construed in singular form, i.e., referring to a single element, or in plural form, i.e. referring to a combination of single elements. Therefore, terminology “means for [performing A, B, C]”, is to be interpreted to cover an apparatus in which there is only one means for performing A, B and C, or where there are separate means for performing A, B and C, or partially or fully overlapping means for performing A, B, C. Further, terminology “means for performing A, means for performing B, means for performing C” is to be interpreted to cover an apparatus in which there is only one means for performing A, B and C, or where there are separate means for performing A, B and C, or partially or fully overlapping means for performing A, B, C.

[0145] Referring now to FIG. 7, a process flow diagram of a method 600 is illustrated. The method 600 can comprise: receiving, at a user equipment (UE), receiving, at a user equipment (UE), a mobility configuration associated with one or more candidate cells, wherein the UE is configured to initiate a cell switch to at least one candidate cell based upon at least one condition being satisfied, at 602. The method 600 can further comprise: initiating monitoring of the at least one condition for initiating the cell switch to the at least one candidate cell or at least one reference signal (RS) configured for the at least one candidate cell, at 604. The method 600 can further comprise: based on initiating the monitoring of the at least one condition for the cell switch, initiating one or more cell switch preparation actions for the at least one candidate cell or the at least one RS configured for the at least one candidate cell, at 606. The method 600 can further comprise: after completion of performance of the one or more cell switch preparation actions, maintaining the one or more cell switch preparation actions until a predefined event, at 608. The method 600 can further comprise: in an instance in which a cell switch to a particular candidate cell is initiated before completion of performance of the one or more cell switch preparation actions and before occurrence of the predefined event, completing a remaining required portion of the one or more cell switch preparation actions during the cell switch to the particular candidate cell, at 610.

[0146] The method 600 can be carried out in part or in full by means, such as apparatus 500. In some embodiments, the elements of the method 600 can be carried out by means, such as the processor 512 and memory 514 storing instructions 515 thereon that, when executed by the processor 512, cause the apparatus 500 to perform elements 602, 604, 606, 608, and 610 of the method 600. In other embodiments, a computer program product, such as a non-transitory computer-readable storage medium (e.g., 514) can be provided that stores instructions (e.g., 515) thereon that, when executed by means, such as an apparatus (e.g., 500) and / or the processor (512) and memory (514) thereof, cause some or all elements of the method 600 to be performed.

[0147] Referring now to FIG. 8, a process flow diagram of a method 700 is illustrated. The method 700 can comprise: receiving, at a user equipment (UE), a mobility configuration associated with one or morecandidate cells, wherein the UE is configured to initiate a cell switch to at least one candidate cell based upon at least one condition being satisfied, at 702. The method 700 can further comprise: initiating monitoring of the at least one condition for initiating the cell switch to the at least one candidate cell or at least one reference signal (RS) configured for the at least one candidate cell, at 704. The method 700 can further comprise: based on initiating the monitoring of the at least one condition for the cell switch, initiating one or more cell switch preparation actions for the at least one candidate cell or the at least one RS configured for the at least one candidate cell, at 706. The method 700 can further comprise: after completion of performance of the one or more cell switch preparation actions, maintaining the one or more cell switch preparation actions until a predefined event, at 708. The method 700 can further comprise: in an instance in which a cell switch to a particular candidate cell is initiated after completion of performance of the one or more cell switch preparation actions and before occurrence of the predefined event, initiating the cell switch to the particular candidate cell without completing any of the one or more cell switch preparation actions during the cell switch to the particular candidate cell, at 710.

[0148] The method 700 can be carried out in part or in full by means, such as apparatus 500. In some embodiments, the elements of the method 700 can be carried out by means, such as the processor 512 and memory 514 storing instructions 515 thereon that, when executed by the processor 512, cause the apparatus 500 to perform elements 702, 704, 706, 708, and 710 of the method 700. In other embodiments, a computer program product, such as a non-transitory computer-readable storage medium (e.g., 514) can be provided that stores instructions (e.g., 515) thereon that, when executed by means, such as an apparatus (e.g., 500) and / or the processor (512) and memory (514) thereof, cause some or all elements of the method 700 to be performed.

[0149] Referring now to FIG. 9, a process flow diagram of a method 800 is illustrated. The method 800 can comprise: receiving, at a user equipment (UE), a Layer 1 / Layer 2 triggered mobility (LTM) configuration associated with one or more candidate cells, wherein the UE is configured to initiate a Conditional LTM (CLTM) cell switch to at least one candidate cell based upon at least one CLTM condition being satisfied, at 802. The method 800 can further comprise: initiating monitoring of the at least one CLTM condition for CLTM cell switch to the at least one candidate cell or at least one reference signal (RS) configured for the at least one candidate cell, at 804. The method 800 can further comprise: based on initiating the monitoring of the at least one CLTM condition for CLTM cell switch, initiating one or more CLTM cell switch preparation actions for the at least one candidate cell or the at least one RS configured for the at least one candidate cell, at 806. The method 800 can further comprise: after completion of performance of the one or more CLTM cell switch preparation actions, maintaining the one or more CLTM cell switch preparation actions until a predefined event, at 808. The method 800 can further comprise: in an instance in which a cell switch is initiated after completion of performance of the one or more CLTM cell switch preparation actions and before occurrence of a predefined event other than initiation or completion of the cell switch, completing the cell switch within a cell switch delay period that doesnot comprise one or more cell switch delay subperiods associated with the one or more CLTM cell switch preparation actions, at 810.

[0150] The method 800 can be carried out in part or in full by means, such as apparatus 500. In some embodiments, the elements of the method 800 can be carried out by means, such as the processor 512 and memory 514 storing instructions 515 thereon that, when executed by the processor 512, cause the apparatus 500 to perform elements 802, 804, 806, 808, and 810 of the method 800. In other embodiments, a computer program product, such as a non-transitory computer-readable storage medium (e.g., 514) can be provided that stores instructions (e.g., 515) thereon that, when executed by means, such as an apparatus (e.g., 500) and / or the processor (512) and memory (514) thereof, cause some or all elements of the method 800 to be performed.

[0151] Referring now to FIG. 10, a process flow diagram of a method 900 is illustrated. The method 900 can comprise: storing, at a user equipment (UE), one or more conditional lower-layer triggered mobility (CLTM) conditions, the one or more CLTM conditions being associated with one or more candidate cells in a mobile network, at 902. The method 900 can further comprise: initiating a transmission / reception point (TRP) condition evaluation for the one or more candidate cells, at 904. The method 900 can further comprise: in an instance in which an LTM procedure or a CLTM procedure is initiated for cell switching to a particular candidate cell from among the one or more candidate cells after completion of the TRP condition evaluation for the particular candidate cell, transmitting an initial transmission to the mobile network via the particular candidate cell, at 906. The method 900 can further comprise: in an instance in which the LTM procedure or the CLTM procedure is initiated for cell switching to the particular candidate cell from among the one or more candidate cells before completion of the TRP condition evaluation for the particular candidate cell, performing one or more incomplete required CLTM cell switch preparation tasks during the LTM procedure or the CLTM procedure, at 908. The method 900 can, optionally, further comprise: receiving a cell switch command from a source cell currently serving the UE, at 91O.The method 900 can, optionally, further comprise initiating a cell switch command based cell switch to the particular candidate cell, at 912.

[0152] The method 900 can be carried out in part or in full by means, such as apparatus 500. In some embodiments, the elements of the method 900 can be carried out by means, such as the processor 512 and memory 514 storing instructions 515 thereon that, when executed by the processor 512, cause the apparatus 500 to perform elements 902, 904, 906, and 908, and optionally to perform elements 910 and 912 of the method 900. In other embodiments, a computer program product, such as a non-transitory computer-readable storage medium (e.g., 514) can be provided that stores instructions (e.g., 515) thereon that, when executed by means, such as an apparatus (e.g., 500) and / or the processor (512) and memory (514) thereof, cause some or all elements of the method 900 to be performed.

[0153] Referring now to FIG. 11, a process flow diagram of a method 1000 is illustrated. The method 1000 can comprise: storing, at a user equipment (UE), one or more conditional lower-layer triggered mobility (CLTM) conditions, the one or more CLTM conditions being associated with one or more candidate cells in a mobilenetwork, at 1002. The method 1000 can further comprise: initiating, at 1004, one or more CLTM switch preparation actions for a particular candidate cell from among the one or more candidate cells, at 1006. The method 1000 can, optionally, further comprise performing Abstract Syntax Notation One (ASN.1) decoding and validity check for a candidate cell configuration associated with the particular candidate cell, at 1008. The method 1000 can, optionally, further comprise performing path loss reference signal (PL-RS) estimation for an RS associated with the particular candidate cell, at 1010. The method 1000 can, optionally, further comprise performing acquiring timing advance (TA) for the particular candidate cell based on random access channel (RACH) information about the particular candidate cell or one or more UE -performed measurements of the particular candidate cell, at 1012. As illustrated in FIG. 11, each of 1006, 1008, 1010, and 1012 are optional elements.

[0154] The method 1000 can be carried out in part or in full by means, such as apparatus 500. In some embodiments, the elements of the method 1000 can be carried out by means, such as the processor 512 and memory 514 storing instructions 515 thereon that, when executed by the processor 512, cause the apparatus 500 to perform elements 1002 and 1004, and, optionally, perform elements 1006 , 1008, 1010, and 1012 of the method 900. In other embodiments, a computer program product, such as a non-transitory computer-readable storage medium (e.g., 514) can be provided that stores instructions (e.g., 515) thereon that, when executed by means, such as an apparatus (e.g., 500) and / or the processor (512) and memory (514) thereof, cause some or all elements of the method 1000 to be performed.

[0155] Referring now to FIG. 12, a process flow diagram of a method 1100 is illustrated. The method 1100 can comprise: in an instance in which the UE is configured with one or more Conditional Layer 1 / Layer 2 Triggered Mobility (CLTM) conditions for initiating a CLTM cell switch to one or more candidate cells in a mobile network, initiating monitoring, using the UE, for the one or more CLTM conditions for CLTM cell switch associated with the respective cells of the one or more candidate cells, at 1102. The method 1100 can further comprise: initiating, at the UE, CLTM cell switch preparation tasks for the CLTM cell switch to respective candidate cells of the one or more candidate cells, at 1104. The method 1100 can further comprise: determining whether at least one CLTM condition of the one or more CLTM conditions is satisfied, the at least one CLTM condition being conditions for CLTM cell switch to a particular network, at 1106. The method 1100 can further comprise: in an instance in which the at least one CLTM condition associated with the particular candidate cell is satisfied, determining whether the CLTM cell switch preparation tasks for the CLTM cell switch to the particular candidate cell are complete, at 1108. The method 1100 can further comprise: in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are incomplete, completing the one or more CLTM cell switch preparation tasks during the cell switch, at 1110. The method 1100 can further comprise: in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are complete, completing the cell switch within a cell switchdelay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks, at 1112.

[0156] The method 1100 can be carried out in part or in full by means, such as apparatus 500. In some embodiments, the elements of the method 1100 can be carried out by means, such as the processor 512 and memory 514 storing instructions 515 thereon that, when executed by the processor 512, cause the apparatus 500 to perform elements 1102, 1004 , 1106, 1108, 1110, and / or 1112 of the method 1100. In other embodiments, a computer program product, such as a non-transitory computer-readable storage medium (e.g., 514) can be provided that stores instructions (e.g., 515) thereon that, when executed by means, such as an apparatus (e.g., 500) and / or the processor (512) and memory (514) thereof, cause some or all elements of the method 1100 to be performed.

[0157] Even though the invention has been described above with reference to an example according to the accompanying drawings, it is clear that the invention is not restricted thereto but can be modified in several ways within the scope of the appended claims. Therefore, all words and expressions should be interpreted broadly, and they are intended to illustrate, not to restrict, the embodiment. It will be obvious to a person skilled in the art that, as technology advances, the inventive concept can be implemented in various ways. Further, it is clear to a person skilled in the art that the described embodiments may, but are not required to, be combined with other embodiments in various ways.

[0158] FIGs. 2-5 and 7-12 illustrate signal flow diagrams and flowcharts depicting methods according to example embodiments. It will be understood that each block or signal and combination of blocks and signals may be implemented by various means, such as hardware, firmware, processor, circuitry, and / or other communication devices associated with execution of software including one or more computer program instructions. For example, one or more of the procedures described above may be embodied by computer program instructions. In this regard, the computer program instructions which embody the procedures described above may be stored by the memory 514 of the apparatus 500 employing an example embodiment and executed by processing circuitry, such as the processor 512. As will be appreciated, any such computer program instructions, such as instructions 515, may be loaded onto a computer or other programmable apparatus (for example, hardware) to produce a machine, such that the resulting computer or other programmable apparatus implements the functions specified in the flowchart blocks. These computer program instructions may also be stored in a computer-readable memory that may direct a computer or other programmable apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture the execution of which implements the function specified in the flowchart blocks. The computer program instructions may also be loaded onto a computer or other programmable apparatus to cause a series of operations to be performed on the computer or other programmable apparatus to produce a computer- implemented process such that the instructions which execute on the computer or other programmable apparatus provide operations for implementing the functions specified in the flowchart blocks.

[0159] Described herein, according to some aspects, is the subject matter of the independent claims. Some further aspects are defined in the dependent claims. The embodiments that do not fall under the scope of the claims are to be interpreted as examples useful for understanding the disclosure.

[0160] According to an embodiment, a device or apparatus, such as a user equipment (UE) is provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the UE to perform receiving a Layer 1 / Layer 2 triggered mobility (LTM) configuration associated with one or more candidate cells, wherein the UE is configured to initiate a Conditional LTM (CLTM) cell switch to at least one candidate cell based upon at least one CLTM condition being satisfied. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform initiating monitoring of the at least one CLTM condition for CLTM cell switch to the at least one candidate cell or at least one reference signal (RS) configured for the at least one candidate cell. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, based on initiating the monitoring of the at least one CLTM condition for CLTM cell switch, initiating one or more CLTM cell switch preparation actions for the at least one candidate cell or the at least one RS configured for the at least one candidate cell. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, after completion of performance of the one or more LTM / CLTM cell switch preparation actions, maintaining the one or more LTM / CLTM cell switch preparation actions until a predefined event. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which a cell switch is initiated after completion of performance of the one or more CLTM cell switch preparation actions and before occurrence of a predefined event other than initiation or completion of the cell switch, completing the cell switch within a cell switch delay period that does not comprise one or more cell switch delay subperiods associated with the one or more CLTM cell switch preparation actions.

[0161] In some embodiments, the one or more CLTM cell switch preparation actions comprise at least one of: monitoring fine downlink timing for the particular candidate cell, monitoring frequency synchronization for the particular candidate cell, monitoring fine downlink timing for a reference signal (RS) associated with the particular candidate cell, monitoring frequency synchronization for the RS associated with the particular candidate cell, ASN.1 decoding, ASN.1 validity check, storing a decoded configuration of the candidate cell at the UE, monitoring a path loss estimate associated with the RS associated with the particular candidate cell, performing timing advance (TA) delay estimation for the particular candidate cell, determining a delay for UE- based TA estimation for the particular candidate cell, or estimating path loss reference signal (PL-RS) delay for the particular candidate cell.

[0162] In some embodiments, the predefined event until which the UE maintains the one or more CLTM cell switch preparation actions is at least one of: initiation / completion of cell switch based on reception of cellswitch command or condition of CLTM cell switch becoming fulfilled, configuration of UE stopping CLTM condition evaluation for the candidate cell or RS configured for the candidate cell, or preconfigured / predefmed time for preparation action maintenance expiring. In some embodiments, the one or more CLTM switch preparation actions are carried out by the UE in parallel, in series, or partially in parallel and partially in series.

[0163] In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform receiving, at the UE, from a network element of the mobile network, information about which of a plurality of CLTM switch preparation actions the UE is to perform at the initiation of the monitoring of the at least one CLTM condition for CLTM cell switch. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, upon receiving the information about which of a plurality of CLTM switch preparation actions to perform, initiating the indicated CLTM cell switch preparation tasks in the received information.

[0164] In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform receiving, at the UE, from a network element of the mobile network, information about an order in which the UE is to perform the one or more CLTM switch preparation actions. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the information about the order in which the UE is to perform the one or more CLTM switch preparation actions indicates that all of the one or more CLTM switch preparation actions are to be performed in parallel, determining, at the UE, based at least on a respective delay estimate for each of the one or more CLTM switch preparation actions, a total CLTM switch preparation delay estimate associated with the particular candidate cell to be a maximum delay estimate from among the respective delay actions for the one or more CLTM switch preparation actions. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the information about the order in which the UE is to perform the one or more CLTM switch preparation actions indicates that all of the one or more CLTM switch preparation actions are to be performed serially, determining, at the UE, based at least on a sum of the respective delay estimates for the one or more CLTM switch preparation actions, a total CLTM switch preparation delay estimate associated with the particular candidate cell.

[0165] In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the UE receives a cell switch command to perform a cell switch from a serving cell to the particular candidate cell or another candidate cell, determining that one or more required CLTM cell switch preparation tasks remain incomplete for the particular candidate cell or the another candidate cell, completing the incomplete CLTM cell switch preparation tasks during the cell switch. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the UE receives a cell switch command to perform a cell switch from a serving cell to the particular candidate cell or another candidatecell, determining that all required CLTM cell switch preparation tasks have been completed for the particular candidate cell or the another candidate cell, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0166] In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which a CLTM cell switch to the particular candidate cell is triggered based upon a CLTM condition associated with the particular candidate cell being met, determining whether the CLTM cell switch is being triggered before completion of one or more required CLTM cell switch preparation tasks. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which one or more required CLTM cell switch preparation tasks are incomplete, completing the one or more CLTM cell switch preparation tasks required for CLTM cell switch to the particular candidate cell during the cell switch. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the one or more required CLTM cell switch preparation tasks are complete, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0167] According to another embodiment, a method can be performed, e.g., by a UE, which comprises receiving a Layer 1 / Layer 2 triggered mobility (LTM) configuration associated with one or more candidate cells, wherein the UE is configured to initiate a Conditional LTM (CLTM) cell switch to at least one candidate cell based upon at least one CLTM condition being satisfied. In some embodiments, the method further comprises initiating monitoring of the at least one CLTM condition for CLTM cell switch to the at least one candidate cell or at least one reference signal (RS) configured for the at least one candidate cell. In some embodiments, the method further comprises, based on initiating the monitoring of the at least one CLTM condition for CLTM cell switch, initiating one or more CLTM cell switch preparation actions for the at least one candidate cell or the at least one RS configured for the at least one candidate cell. In some embodiments, the method further comprises, after completion of performance of the one or more CLTM cell switch preparation actions, maintaining the one or more CLTM cell switch preparation actions until a predefined event. In some embodiments, the method further comprises, in an instance in which a cell switch is initiated after completion of performance of the one or more CLTM cell switch preparation actions and before occurrence of a predefined event other than initiation or completion of the cell switch, completing the cell switch within a cell switch delay period that does not comprise one or more cell switch delay subperiods associated with the one or more CLTM cell switch preparation actions.

[0168] In some embodiments, the one or more CLTM cell switch preparation actions comprise at least one of: monitoring fine downlink timing for the particular candidate cell, monitoring frequency synchronization for the particular candidate cell, monitoring fine downlink timing for a reference signal (RS) associated with the particular candidate cell, monitoring frequency synchronization for the RS associated with the particularcandidate cell, ASN.1 decoding, ASN.1 validity check, storing a decoded configuration of the candidate cell at the UE, monitoring a path loss estimate associated with the RS associated with the particular candidate cell, performing timing advance (TA) delay estimation for the particular candidate cell, determining a delay for UE- based TA estimation for the particular candidate cell, or estimating path loss reference signal (PL-RS) delay for the particular candidate cell.

[0169] In some embodiments, the predefined event until which the UE maintains the one or more CLTM cell switch preparation actions is at least one of: initiation / completion of cell switch based on reception of cell switch command or condition of CLTM cell switch becoming fulfilled, configuration of UE stopping CLTM condition evaluation for the candidate cell or RS configured for the candidate cell, or preconfigured / predefmed time for preparation action maintenance expiring. In some embodiments, the one or more CLTM switch preparation actions are carried out by the UE in parallel, in series, or partially in parallel and partially in series.

[0170] In some embodiments, the method further comprises receiving, at the UE, from a network element of the mobile network, information about which of a plurality of CLTM switch preparation actions the UE is to perform. In some embodiments, the method further comprises, in an instance in which the information about which of the plurality of CLTM cell switch preparation tasks the UE is to perform indicates that the UE is to perform only the one or more CLTM cell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks, initiating the one or more CLTM cell switch preparation tasks at the UE. In some embodiments, the method further comprises, in an instance in which the information about which of the plurality of CLTM cell switch preparation tasks the UE is to perform indicates that the UE is to perform a subset of CLTM cell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks the subset of CLTM cell switch preparation tasks comprising the one or more CLTM cell switch preparation tasks for the CLTM cell switch to the particular candidate cell, initiating, at the UE, the subset of CLTM cell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks.

[0171] In some embodiments, the method further comprises receiving, at the UE, from a network element of the mobile network, information about an order in which the UE is to perform the one or more CLTM switch preparation actions. In some embodiments, the method further comprises, in an instance in which the information about the order in which the UE is to perform the one or more CLTM switch preparation actions indicates that all of the one or more CLTM switch preparation actions are to be performed in parallel, determining, at the UE, based at least on a respective delay estimate for each of the one or more CLTM switch preparation actions, a total CLTM switch preparation delay estimate associated with the particular candidate cell to be a maximum delay estimate from among the respective delay actions for the one or more CLTM switch preparation actions. In some embodiments, the method further comprises, in an instance in which the information about the order in which the UE is to perform the one or more CLTM switch preparation actions indicates that all of the one or more CLTM switch preparation actions are to be performed serially, determining, at the UE, based at least on asum of the respective delay estimates for the one or more CLTM switch preparation actions, a total CLTM switch preparation delay estimate associated with the particular candidate cell.

[0172] In some embodiments, the method further comprises, in an instance in which the UE receives a cell switch command to perform a cell switch from a serving cell to the particular candidate cell or another candidate cell, determining that one or more required CLTM cell switch preparation tasks remain incomplete for the particular candidate cell or the another candidate cell, completing the one or more required CLTM cell switch preparation tasks during the cell switch. In some embodiments, the method further comprises, in an instance in which the UE receives a cell switch command to perform a cell switch from a serving cell to the particular candidate cell or another candidate cell, determining that all required CLTM cell switch preparation tasks have been completed for the particular candidate cell or the another candidate cell, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0173] In some embodiments, the method further comprises, in an instance in which a CLTM cell switch to the particular candidate cell is triggered based upon a CLTM condition associated with the particular candidate cell being met, determining whether the CLTM cell switch is being triggered before completion of one or more required CLTM cell switch preparation tasks for the particular candidate cell. In some embodiments, the method further comprises, in an instance in which one or more required CLTM cell switch preparation tasks are incomplete, completing the one or more required CLTM cell switch preparation tasks required for CLTM cell switch to the particular candidate cell during the cell switch. In some embodiments, the method further comprises, in an instance in which the one or more required CLTM cell switch preparation tasks are complete, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0174] According to another embodiment, a computer program product can be provided that is or comprises, e.g., a non-transitory computer-readable storage medium comprising instructions stored thereon that, when executed by at least one processor, cause a user equipment (UE) to perform at least receiving a Layer 1 / Layer 2 triggered mobility (LTM) configuration associated with one or more candidate cells, wherein the UE is configured to initiate a Conditional LTM (CLTM) cell switch to at least one candidate cell based upon at least one CLTM condition being satisfied. In some embodiments, the instruction stored thereon, when executed by the at least one processor, further cause the UE to perform initiating monitoring of the at least one CLTM condition for CLTM cell switch to the at least one candidate cell or at least one reference signal (RS) configured for the at least one candidate cell. In some embodiments, the instruction stored thereon, when executed by the at least one processor, further cause the UE to perform, based on initiating the monitoring of the at least one CLTM condition for CLTM cell switch, initiating one or more CLTM cell switch preparation actions for the at least one candidate cell or the at least one RS configured for the at least one candidate cell. In some embodiments, the instruction stored thereon, when executed by the at least one processor, further cause the UE to perform, aftercompletion of performance of the one or more CLTM cell switch preparation actions, maintaining the one or more CLTM cell switch preparation actions until a predefined event. In some embodiments, the instruction stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which a cell switch is initiated after completion of performance of the one or more CLTM cell switch preparation actions and before occurrence of a predefined event other than initiation or completion of the cell switch, completing the cell switch within a cell switch delay period that does not comprise one or more cell switch delay subperiods associated with the one or more CLTM cell switch preparation actions.

[0175] In some embodiments, the one or more CLTM cell switch preparation actions comprise at least one of: monitoring fine downlink timing for the particular candidate cell, monitoring frequency synchronization for the particular candidate cell, monitoring fine downlink timing for a reference signal (RS) associated with the particular candidate cell, monitoring frequency synchronization for the RS associated with the particular candidate cell, ASN.1 decoding, ASN.1 validity check, storing a decoded configuration of the candidate cell at the UE, monitoring a path loss estimate associated with the RS associated with the particular candidate cell, performing timing advance (TA) delay estimation for the particular candidate cell, determining a delay for UE- based TA estimation for the particular candidate cell, or estimating path loss reference signal (PL-RS) delay for the particular candidate cell.

[0176] In some embodiments, the predefined event until which the UE maintains the one or more CLTM cell switch preparation actions is at least one of: initiation / completion of cell switch based on reception of cell switch command or condition of CLTM cell switch becoming fulfilled, configuration of UE stopping CLTM condition evaluation for the candidate cell or RS configured for the candidate cell, or preconfigured / predefined time for preparation action maintenance expiring. In some embodiments, the one or more CLTM switch preparation actions are carried out by the UE in parallel, in series, or partially in parallel and partially in series.

[0177] In some embodiments, the instruction stored thereon, when executed by the at least one processor, further cause the UE to perform receiving, at the UE, from a network element of the mobile network, information about which of a plurality of CLTM switch preparation actions the UE is to perform. In some embodiments, the instruction stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which the information about which of the plurality of CLTM cell switch preparation tasks the UE is to perform indicates that the UE is to perform only the one or more CLTM cell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks, initiating the one or more CLTM cell switch preparation tasks at the UE. In some embodiments, the instruction stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which the information about which of the plurality of CLTM cell switch preparation tasks the UE is to perform indicates that the UE is to perform a subset of CLTM cell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks the subset of CLTM cell switch preparation tasks comprising the one or more CLTM cell switch preparation tasksfor the CLTM cell switch to the particular candidate cell, initiating, at the UE, the subset of CLTM cell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks.

[0178] In some embodiments, the instruction stored thereon, when executed by the at least one processor, further cause the UE to perform receiving, at the UE, from a network element of the mobile network, information about an order in which the UE is to perform the one or more CLTM switch preparation actions. In some embodiments, the instruction stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which the information about the order in which the UE is to perform the one or more CLTM switch preparation actions indicates that all of the one or more CLTM switch preparation actions are to be performed in parallel, determining, at the UE, based at least on a respective delay estimate for each of the one or more CLTM switch preparation actions, a total CLTM switch preparation delay estimate associated with the particular candidate cell to be a maximum delay estimate from among the respective delay actions for the one or more CLTM switch preparation actions. In some embodiments, the instruction stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which the information about the order in which the UE is to perform the one or more CLTM switch preparation actions indicates that all of the one or more CLTM switch preparation actions are to be performed serially, determining, at the UE, based at least on a sum of the respective delay estimates for the one or more CLTM switch preparation actions, a total CLTM switch preparation delay estimate associated with the particular candidate cell.

[0179] In some embodiments, the instruction stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which the UE receives a cell switch command to perform a cell switch from a serving cell to the particular candidate cell or another candidate cell, determining that one or more required CLTM cell switch preparation tasks remain incomplete for the particular candidate cell or the another candidate cell, completing the one or more required CLTM cell switch preparation tasks during the cell switch. In some embodiments, the instruction stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which the UE receives a cell switch command to perform a cell switch from a serving cell to the particular candidate cell or another candidate cell, determining that all required CLTM cell switch preparation tasks have been completed for the particular candidate cell or the another candidate cell, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0180] In some embodiments, the instruction stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which a CLTM cell switch to the particular candidate cell is triggered based upon a CLTM condition associated with the particular candidate cell being met, determining whether the CLTM cell switch is being triggered before completion of one or more required CLTM cell switch preparation tasks for the particular candidate cell. In some embodiments, the instruction stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which one or more required CLTM cell switch preparation tasks are incomplete, completing the one or more required CLTM cell31switch preparation tasks required for CLTM cell switch to the particular candidate cell during the cell switch. In some embodiments, the instruction stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which the one or more required CLTM cell switch preparation tasks are complete, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0181] According to another embodiment, an apparatus can be provided that comprises means, such as a processor and memory storing instructions thereon that, when executed by the processor, cause the apparatus to perform all or part of a method. For example, the apparatus can comprise means for receiving a Layer 1 / Layer 2 triggered mobility (LTM) configuration associated with one or more candidate cells, wherein the apparatus is configured to initiate a Conditional LTM (CLTM) cell switch to at least one candidate cell based upon at least one CLTM condition being satisfied. In some embodiments, the apparatus can further comprise means for initiating monitoring of the at least one CLTM condition for CLTM cell switch to the at least one candidate cell or at least one reference signal (RS) configured for the at least one candidate cell. In some embodiments, the apparatus can further comprise means for, based on initiating the monitoring of the at least one CLTM condition for CLTM cell switch, initiating one or more CLTM cell switch preparation actions for the at least one candidate cell or the at least one RS configured for the at least one candidate cell. In some embodiments, the apparatus can further comprise means for, after completion of performance of the one or more CLTM cell switch preparation actions, maintaining the one or more CLTM cell switch preparation actions until a predefined event. In some embodiments, the apparatus can further comprise means for, in an instance in which a cell switch is initiated after completion of performance of the one or more CLTM cell switch preparation actions and before occurrence of a predefined event other than initiation or completion of the cell switch, completing the cell switch within a cell switch delay period that does not comprise one or more cell switch delay subperiods associated with the one or more CLTM cell switch preparation actions.

[0182] In some embodiments, the one or more CLTM cell switch preparation actions comprise at least one of: monitoring fine downlink timing for the particular candidate cell, monitoring frequency synchronization for the particular candidate cell, monitoring fine downlink timing for a reference signal (RS) associated with the particular candidate cell, monitoring frequency synchronization for the RS associated with the particular candidate cell, ASN.1 decoding, ASN.1 validity check, storing a decoded configuration of the candidate cell at the apparatus, monitoring a path loss estimate associated with the RS associated with the particular candidate cell, performing timing advance (TA) delay estimation for the particular candidate cell, determining a delay for UE-based TA estimation for the particular candidate cell, or estimating path loss reference signal (PL-RS) delay for the particular candidate cell.

[0183] In some embodiments, the predefined event until which the apparatus maintains the one or more CLTM cell switch preparation actions is at least one of: initiation / completion of cell switch based on reception of cell switch command or condition of CLTM cell switch becoming fulfilled, configuration of the apparatusstopping CLTM condition evaluation for the candidate cell or RS configured for the candidate cell, or preconfigured / predefined time for preparation action maintenance expiring. In some embodiments, the one or more CLTM switch preparation actions are carried out by the apparatus in parallel, in series, or partially in parallel and partially in series.

[0184] In some embodiments, the apparatus can further comprise means for receiving, from a network element of the mobile network, information about which of a plurality of CLTM switch preparation actions the UE is to perform. In some embodiments, the apparatus can further comprise means for, in an instance in which the information about which of the plurality of CLTM cell switch preparation tasks the apparatus is to perform indicates that the apparatus is to perform only the one or more CLTM cell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks, initiating the one or more CLTM cell switch preparation tasks at the apparatus. In some embodiments, the apparatus can further comprise means for, in an instance in which the information about which of the plurality of CLTM cell switch preparation tasks the apparatus is to perform indicates that the apparatus is to perform a subset of CLTM cell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks the subset of CLTM cell switch preparation tasks comprising the one or more CLTM cell switch preparation tasks for the CLTM cell switch to the particular candidate cell, initiating the subset of CLTM cell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks.

[0185] In some embodiments, the apparatus can further comprise means for receiving, from a network element of the mobile network, information about an order in which the UE is to perform the one or more CLTM switch preparation actions. In some embodiments, the apparatus can further comprise means for, in an instance in which the information about the order in which the apparatus is to perform the one or more CLTM switch preparation actions indicates that all of the one or more CLTM switch preparation actions are to be performed in parallel, determining, at the UE, based at least on a respective delay estimate for each of the one or more CLTM switch preparation actions, a total CLTM switch preparation delay estimate associated with the particular candidate cell to be a maximum delay estimate from among the respective delay actions for the one or more CLTM switch preparation actions. In some embodiments, the apparatus can further comprise means for, in an instance in which the information about the order in which the apparatus is to perform the one or more CLTM switch preparation actions indicates that all of the one or more CLTM switch preparation actions are to be performed serially, determining, based at least on a sum of the respective delay estimates for the one or more CLTM switch preparation actions, a total CLTM switch preparation delay estimate associated with the particular candidate cell.

[0186] In some embodiments, the apparatus can further comprise means for, in an instance in which the apparatus receives a cell switch command to perform a cell switch from a serving cell to the particular candidate cell or another candidate cell, determining that one or more required CLTM cell switch preparation tasks remain incomplete for the particular candidate cell or the another candidate cell, completing the one or more requiredCLTM cell switch preparation tasks during the cell switch. In some embodiments, the apparatus can further comprise means for, in an instance in which the apparatus receives a cell switch command to perform a cell switch from a serving cell to the particular candidate cell or another candidate cell, determining that all required CLTM cell switch preparation tasks have been completed for the particular candidate cell or the another candidate cell, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0187] In some embodiments, the apparatus can further comprise means for, in an instance in which a CLTM cell switch to the particular candidate cell is triggered based upon a CLTM condition associated with the particular candidate cell being met, determining whether the CLTM cell switch is being triggered before completion of one or more required CLTM cell switch preparation tasks for the particular candidate cell. In some embodiments, the method further comprises, in an instance in which one or more required CLTM cell switch preparation tasks are incomplete, completing the one or more required CLTM cell switch preparation tasks required for CLTM cell switch to the particular candidate cell during the cell switch. In some embodiments, the apparatus can further comprise means for, in an instance in which the one or more required CLTM cell switch preparation tasks are complete, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0188] According to another embodiment, a UE can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the UE to perform at least, in an instance in which the UE is configured with one or more Conditional Layer 1 / Layer 2 Triggered Mobility (CLTM) conditions for initiating a CLTM cell switch to one or more candidate cells in a mobile network, initiating monitoring for the one or more CLTM conditions for CLTM cell switch associated with the respective cells of the one or more candidate cells. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform initiating CLTM cell switch preparation tasks for the CLTM cell switch to respective candidate cells of the one or more candidate cells. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform determining whether at least one CLTM condition of the one or more CLTM conditions is satisfied, the at least one CLTM condition being conditions for CLTM cell switch to a particular network. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the at least one CLTM condition associated with the particular candidate cell is satisfied, determining whether the CLTM cell switch preparation tasks for the CLTM cell switch to the particular candidate cell are complete. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are incomplete, completing the one or more CLTM cell switch preparation tasks during the cell switch. In some embodiments, the instructions stored on the at least onememory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are complete, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks .

[0189] According to another embodiment, a method can be carried out or performed, e.g., by a UE, that comprises, in an instance in which the UE is configured with one or more Conditional Layer 1 / Layer 2 Triggered Mobility (CLTM) conditions for initiating a CLTM cell switch to one or more candidate cells in a mobile network, initiating monitoring, using the UE, for the one or more CLTM conditions for CLTM cell switch associated with the respective cells of the one or more candidate cells. In some embodiments, the method further comprises initiating, at the UE, CLTM cell switch preparation tasks for the CLTM cell switch to respective candidate cells of the one or more candidate cells. In some embodiments, the method further comprises determining whether at least one CLTM condition of the one or more CLTM conditions is satisfied, the at least one CLTM condition being conditions for CLTM cell switch to a particular network. In some embodiments, the method further comprises, in an instance in which the at least one CLTM condition associated with the particular candidate cell is satisfied, determining whether the CLTM cell switch preparation tasks for the CLTM cell switch to the particular candidate cell are complete. In some embodiments, the method further comprises, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are incomplete, completing the one or more CLTM cell switch preparation tasks during the cell switch. In some embodiments, the method further comprises, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are complete, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0190] According to another embodiment, a computer program product can be provided that comprises, e.g., a non-transitory computer-readable storage medium comprising instructions stored thereon that, when executed by at least one processor of a user equipment (UE) cause the UE to perform at least, in an instance in which the UE is configured with one or more Conditional Layer 1 / Layer 2 Triggered Mobility (CLTM) conditions for initiating a CLTM cell switch to one or more candidate cells in a mobile network, initiating monitoring, using the UE, for the one or more CLTM conditions for CLTM cell switch associated with the respective cells of the one or more candidate cells. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform initiating, at the UE, CLTM cell switch preparation tasks for the CLTM cell switch to respective candidate cells of the one or more candidate cells. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform determining whether at least one CLTM condition of the one or more CLTM conditions is satisfied, the at least one CLTM condition being conditions for CLTM cell switch to a particular network. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further causethe UE to perform, in an instance in which the at least one CLTM condition associated with the particular candidate cell is satisfied, determining whether the CLTM cell switch preparation tasks for the CLTM cell switch to the particular candidate cell are complete. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are incomplete, completing the one or more CLTM cell switch preparation tasks during the cell switch. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are complete, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0191] According to an embodiment, a device, such as a user equipment (UE) is provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the UE to perform receiving a Layer 1 / Layer 2 triggered mobility (LTM) configuration associated with one or more candidate cells, wherein the UE is configmed to initiate a Conditional LTM (CLTM) cell switch to at least one candidate cell based upon at least one CLTM condition being satisfied. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform initiating monitoring of the at least one CLTM condition for CLTM cell switch to the at least one candidate cell or at least one reference signal (RS) configmed for the at least one candidate cell. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, based on initiating the monitoring of the at least one CLTM condition for CLTM cell switch, initiating one or more CLTM cell switch preparation actions for the at least one candidate cell or the at least one RS configmed for the at least one candidate cell. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, after completion of performance of the one or more CLTM cell switch preparation actions, maintaining the one or more CLTM cell switch preparation actions until a predefined event. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which a cell switch is initiated after completion of performance of the one or more CLTM cell switch preparation actions and before occurrence of a predefined event other than initiation or completion of the cell switch, completing the cell switch within a cell switch delay period that does not comprise one or more cell switch delay subperiods associated with the one or more CLTM cell switch preparation actions.

[0192] In some embodiments, the one or more CLTM cell switch preparation actions comprise at least one of: monitoring fine downlink timing for the particular candidate cell, monitoring frequency synchronization for the particular candidate cell, monitoring fine downlink timing for a reference signal (RS) associated with the particular candidate cell, monitoring frequency synchronization for the RS associated with the particular candidate cell, ASN.1 decoding, ASN.1 validity check, storing a decoded configuration of the candidate cell atthe UE, monitoring a path loss estimate associated with the RS associated with the particular candidate cell, performing timing advance (TA) delay estimation for the particular candidate cell, determining a delay for UE- based TA estimation for the particular candidate cell, or estimating path loss reference signal (PL-RS) delay for the particular candidate cell. In some embodiments, the predefined event until which the UE maintains the one or more CLTM cell switch preparation actions is at least one of: initiation / completion of cell switch based on reception of cell switch command or condition of CLTM cell switch becoming fulfilled, configuration of UE stopping CLTM condition evaluation for the candidate cell or RS configured for the candidate cell, or preconfigured / predefined time for preparation action maintenance expiring. In some embodiments, the one or more CLTM switch preparation actions are carried out by the UE in parallel, in series, or partially in parallel and partially in series.

[0193] In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform receiving, at the UE, from a network element of the mobile network, information about which of a plurality of CLTM switch preparation actions the UE is to perform. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the information about which of the plurality of CLTM cell switch preparation tasks the UE is to perform indicates that the UE is to perform only the one or more CLTM cell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks, initiating the one or more CLTM cell switch preparation tasks at the UE. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the information about which of the plurality of CLTM cell switch preparation tasks the UE is to perform indicates that the UE is to perform a subset of CLTM cell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks the subset of CLTM cell switch preparation tasks comprising the one or more CLTM cell switch preparation tasks for the CLTM cell switch to the particular candidate cell, initiating, at the UE, the subset of CLTM cell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks.

[0194] In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform receiving, at the UE, from a network element of the mobile network, information about an order in which the UE is to perform the one or more CLTM switch preparation actions. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the information about the order in which the UE is to perform the one or more CLTM switch preparation actions indicates that all of the one or more CLTM switch preparation actions are to be performed in parallel, determining, at the UE, based at least on a respective delay estimate for each of the one or more CLTM switch preparation actions, a total CLTM switch preparation delay estimate associated with the particular candidate cell to be a maximum delay estimate from among the respective delay actions for the one or more CLTM switch preparation actions. In some embodiments,the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the information about the order in which the UE is to perform the one or more CLTM switch preparation actions indicates that all of the one or more CLTM switch preparation actions are to be performed serially, determining, at the UE, based at least on a sum of the respective delay estimates for the one or more CLTM switch preparation actions, a total CLTM switch preparation delay estimate associated with the particular candidate cell.

[0195] In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the UE receives a cell switch command to perform a cell switch from a serving cell to the particular candidate cell or another candidate cell, determining that one or more required CLTM cell switch preparation tasks remain incomplete for the particular candidate cell or the another candidate cell, performing one or more incomplete required CLTM cell switch preparation tasks during cell switch. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the UE receives a cell switch command to perform a cell switch from a serving cell to the particular candidate cell or another candidate cell, determining that all required CLTM cell switch preparation tasks have been completed for the particular candidate cell or the another candidate cell, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0196] In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which a CLTM cell switch to the particular candidate cell is triggered based upon a CLTM condition associated with the particular candidate cell being met, determining whether the CLTM cell switch is being triggered before completion of one or more required CLTM cell switch preparation tasks for the particular candidate cell. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which one or more required CLTM cell switch preparation tasks are incomplete, performing one or more incomplete required CLTM cell switch preparation tasks during CLTM cell switch to the particular candidate cell. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the one or more required CLTM cell switch preparation tasks are complete, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0197] According to another embodiment, a method can be carried out by means, such as a UE comprising a processor and a memory storing instructions thereon. In some embodiments, the method can comprise receiving a Layer 1 / Layer 2 triggered mobility (LTM) configuration associated with one or more candidate cells, wherein the UE is configured to initiate a Conditional LTM (CLTM) cell switch to at least one candidate cell based upon at least one CLTM condition being satisfied. In some embodiments, the method further comprisesinitiating monitoring of the at least one CLTM condition for CLTM cell switch to the at least one candidate cell or at least one reference signal (RS) configured for the at least one candidate cell. In some embodiments, the method further comprises, based on initiating the monitoring of the at least one CLTM condition for CLTM cell switch, initiating one or more CLTM cell switch preparation actions for the at least one candidate cell or the at least one RS configured for the at least one candidate cell. In some embodiments, the method further comprises, after completion of performance of the one or more CLTM cell switch preparation actions, maintaining the one or more CLTM cell switch preparation actions until a predefined event. In some embodiments, the method further comprises, in an instance in which a cell switch is initiated after completion of performance of the one or more CLTM cell switch preparation actions and before occurrence of a predefined event other than initiation or completion of the cell switch, completing the cell switch within a cell switch delay period that does not comprise one or more cell switch delay subperiods associated with the one or more CLTM cell switch preparation actions.

[0198] In some embodiments, the one or more CLTM cell switch preparation actions comprise at least one of: monitoring fine downlink timing for the particular candidate cell, monitoring frequency synchronization for the particular candidate cell, monitoring fine downlink timing for a reference signal (RS) associated with the particular candidate cell, monitoring frequency synchronization for the RS associated with the particular candidate cell, ASN.1 decoding, ASN.1 validity check, storing a decoded configuration of the candidate cell at the UE, monitoring a path loss estimate associated with the RS associated with the particular candidate cell, performing timing advance (TA) delay estimation for the particular candidate cell, determining a delay for UE- based TA estimation for the particular candidate cell, or estimating path loss reference signal (PL-RS) delay for the particular candidate cell.

[0199] In some embodiments, the predefined event until which the UE maintains the one or more CLTM cell switch preparation actions is at least one of: initiation / completion of cell switch based on reception of cell switch command or condition of CLTM cell switch becoming fulfilled, configuration of UE stopping CLTM condition evaluation for the candidate cell or RS configured for the candidate cell, or preconfigured / predefined time for preparation action maintenance expiring. In some embodiments, the one or more CLTM switch preparation actions are carried out by the UE in parallel, in series, or partially in parallel and partially in series.

[0200] In some embodiments, the method further comprises receiving, at the UE, from a network element of the mobile network, information about which of a plurality of CLTM switch preparation actions the UE is to perform. In some embodiments, the method further comprises, in an instance in which the information about which of the plurality of CLTM cell switch preparation tasks the UE is to perform indicates that the UE is to perform only the one or more CLTM cell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks, initiating the one or more CLTM cell switch preparation tasks at the UE. In some embodiments, the method further comprises, in an instance in which the information about which of the plurality of CLTM cell switch preparation tasks the UE is to perform indicates that the UE is to perform a subset of CLTMcell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks the subset of CLTM cell switch preparation tasks comprising the one or more CLTM cell switch preparation tasks for the CLTM cell switch to the particular candidate cell, initiating, at the UE, the subset of CLTM cell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks.

[0201] In some embodiments, the method further comprises receiving, at the UE, from a network element of the mobile network, information about an order in which the UE is to perform the one or more CLTM switch preparation actions. In some embodiments, the method further comprises, in an instance in which the information about the order in which the UE is to perform the one or more CLTM switch preparation actions indicates that all of the one or more CLTM switch preparation actions are to be performed in parallel, determining, at the UE, based at least on a respective delay estimate for each of the one or more CLTM switch preparation actions, a total CLTM switch preparation delay estimate associated with the particular candidate cell to be a maximum delay estimate from among the respective delay actions for the one or more CLTM switch preparation actions. In some embodiments, the method further comprises, in an instance in which the information about the order in which the UE is to perform the one or more CLTM switch preparation actions indicates that all of the one or more CLTM switch preparation actions are to be performed serially, determining, at the UE, based at least on a sum of the respective delay estimates for the one or more CLTM switch preparation actions, a total CLTM switch preparation delay estimate associated with the particular candidate cell.

[0202] In some embodiments, the method further comprises, in an instance in which the UE receives a cell switch command to perform a cell switch from a serving cell to the particular candidate cell or another candidate cell, determining that one or more required CLTM cell switch preparation tasks remain incomplete for the particular candidate cell or the another candidate cell, performing one or more incomplete required CLTM cell switch preparation tasks during cell switch. In some embodiments, the method further comprises, in an instance in which the UE receives a cell switch command to perform a cell switch from a serving cell to the particular candidate cell or another candidate cell, determining that all required CLTM cell switch preparation tasks have been completed for the particular candidate cell or the another candidate cell, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0203] In some embodiments, the method further comprises, in an instance in which a CLTM cell switch to the particular candidate cell is triggered based upon a CLTM condition associated with the particular candidate cell being met, determining whether the CLTM cell switch is being triggered before completion of one or more required CLTM cell switch preparation tasks for the particular candidate cell. In some embodiments, the method further comprises, in an instance in which one or more required CLTM cell switch preparation tasks are incomplete, performing one or more incomplete required CLTM cell switch preparation tasks during CLTM cell switch to the particular candidate cell. In some embodiments, the method further comprises, in an instance in which the one or more required CLTM cell switch preparation tasks are complete, completing the cell switchwithin a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0204] According to another embodiment, a computer program product can be provided that comprises, e.g., a non-transitory computer-readable storage medium comprising instructions stored thereon that, when executed by at least one processor, cause a user equipment (UE) to perform receiving a Layer 1 / Layer 2 triggered mobility (LTM) configuration associated with one or more candidate cells, wherein the UE is configured to initiate a Conditional LTM (CLTM) cell switch to at least one candidate cell based upon at least one CLTM condition being satisfied. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform initiating monitoring of the at least one CLTM condition for CLTM cell switch to the at least one candidate cell or at least one reference signal (RS) configured for the at least one candidate cell. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform, based on initiating the monitoring of the at least one CLTM condition for CLTM cell switch, initiating one or more CLTM cell switch preparation actions for the at least one candidate cell or the at least one RS configured for the at least one candidate cell. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform, after completion of performance of the one or more CLTM cell switch preparation actions, maintaining the one or more CLTM cell switch preparation actions until a predefined event. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which a cell switch is initiated after completion of performance of the one or more CLTM cell switch preparation actions and before occurrence of a predefined event other than initiation or completion of the cell switch, completing the cell switch within a cell switch delay period that does not comprise one or more cell switch delay subperiods associated with the one or more CLTM cell switch preparation actions.

[0205] In some embodiments, the one or more CLTM cell switch preparation actions comprise at least one of: monitoring fine downlink timing for the particular candidate cell, monitoring frequency synchronization for the particular candidate cell, monitoring fine downlink timing for a reference signal (RS) associated with the particular candidate cell, monitoring frequency synchronization for the RS associated with the particular candidate cell, ASN.1 decoding, ASN.1 validity check, storing a decoded configuration of the candidate cell at the UE, monitoring a path loss estimate associated with the RS associated with the particular candidate cell, performing timing advance (TA) delay estimation for the particular candidate cell, determining a delay for UE- based TA estimation for the particular candidate cell, or estimating path loss reference signal (PL-RS) delay for the particular candidate cell.

[0206] In some embodiments, the predefined event until which the UE maintains the one or more CLTM cell switch preparation actions is at least one of: initiation / completion of cell switch based on reception of cell switch command or condition of CLTM cell switch becoming fulfilled, configuration of UE stopping CLTM condition evaluation for the candidate cell or RS configured for the candidate cell, or preconfigured / predefinedtime for preparation action maintenance expiring. In some embodiments, the one or more CLTM switch preparation actions are carried out by the UE in parallel, in series, or partially in parallel and partially in series.

[0207] In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform receiving, at the UE, from a network element of the mobile network, information about which of a plurality of CLTM switch preparation actions the UE is to perform. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which the information about which of the plurality of CLTM cell switch preparation tasks the UE is to perform indicates that the UE is to perform only the one or more CLTM cell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks, initiating the one or more CLTM cell switch preparation tasks at the UE. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which the information about which of the plurality of CLTM cell switch preparation tasks the UE is to perform indicates that the UE is to perform a subset of CLTM cell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks the subset of CLTM cell switch preparation tasks comprising the one or more CLTM cell switch preparation tasks for the CLTM cell switch to the particular candidate cell, initiating, at the UE, the subset of CLTM cell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks.

[0208] In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform receiving, at the UE, from a network element of the mobile network, information about an order in which the UE is to perform the one or more CLTM switch preparation actions. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which the information about the order in which the UE is to perform the one or more CLTM switch preparation actions indicates that all of the one or more CLTM switch preparation actions are to be performed in parallel, determining, at the UE, based at least on a respective delay estimate for each of the one or more CLTM switch preparation actions, a total CLTM switch preparation delay estimate associated with the particular candidate cell to be a maximum delay estimate from among the respective delay actions for the one or more CLTM switch preparation actions. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which the information about the order in which the UE is to perform the one or more CLTM switch preparation actions indicates that all of the one or more CLTM switch preparation actions are to be performed serially, determining, at the UE, based at least on a sum of the respective delay estimates for the one or more CLTM switch preparation actions, a total CLTM switch preparation delay estimate associated with the particular candidate cell.

[0209] In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which the UE receives a cell switch command to perform a cell switch from a serving cell to the particular candidate cell or another candidate cell, determining that one or more required CLTM cell switch preparation tasks remain incomplete for the particular candidate cell or theanother candidate cell, performing one or more incomplete required CLTM cell switch preparation tasks during cell switch. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which the UE receives a cell switch command to perform a cell switch from a serving cell to the particular candidate cell or another candidate cell, determining that all required CLTM cell switch preparation tasks have been completed for the particular candidate cell or the another candidate cell, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0210] In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which a CLTM cell switch to the particular candidate cell is triggered based upon a CLTM condition associated with the particular candidate cell being met, determining whether the CLTM cell switch is being triggered before completion of one or more required CLTM cell switch preparation tasks for the particular candidate cell. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which one or more required CLTM cell switch preparation tasks are incomplete, performing one or more incomplete required CLTM cell switch preparation tasks during CLTM cell switch to the particular candidate cell. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which the one or more required CLTM cell switch preparation tasks are complete, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0211] According to another embodiment, an apparatus can be provided that comprises means for performing at least a portion of a method or process as described herein. In some embodiments, the means can comprise a processor and memory storing instructions thereon that, when executed by the processor, cause the apparatus to perform some or all of the method or process. In some embodiments, the apparatus comprises means for receiving a Layer 1 / Layer 2 triggered mobility (LTM) configuration associated with one or more candidate cells. In some embodiments, the apparatus is configured to initiate a Conditional LTM (CLTM) cell switch to at least one candidate cell based upon at least one CLTM condition being satisfied. In some embodiments, the apparatus further comprises means for initiating monitoring of the at least one CLTM condition for CLTM cell switch to the at least one candidate cell or at least one reference signal (RS) configured for the at least one candidate cell. In some embodiments, the apparatus further comprises means for, based on initiating the monitoring of the at least one CLTM condition for CLTM cell switch, initiating one or more CLTM cell switch preparation actions for the at least one candidate cell or the at least one RS configured for the at least one candidate cell. In some embodiments, the apparatus further comprises means for, after completion of performance of the one or more CLTM cell switch preparation actions, maintaining the one or more CLTM cell switch preparation actions until a predefined event. In some embodiments, the apparatus further comprises means for, in an instance in which a cell switch is initiated after completion of performance of the one or more CLTMcell switch preparation actions and before occurrence of a predefined event other than initiation or completion of the cell switch, completing the cell switch within a cell switch delay period that does not comprise one or more cell switch delay subperiods associated with the one or more CLTM cell switch preparation actions.

[0212] In some embodiments, the one or more CLTM cell switch preparation actions comprise at least one of: monitoring fine downlink timing for the particular candidate cell, monitoring frequency synchronization for the particular candidate cell, monitoring fine downlink timing for a reference signal (RS) associated with the particular candidate cell, monitoring frequency synchronization for the RS associated with the particular candidate cell, ASN.1 decoding, ASN.1 validity check, storing a decoded configuration of the candidate cell at the apparatus, monitoring a path loss estimate associated with the RS associated with the particular candidate cell, performing timing advance (TA) delay estimation for the particular candidate cell, determining a delay for UE-based TA estimation for the particular candidate cell, or estimating path loss reference signal (PL-RS) delay for the particular candidate cell.

[0213] In some embodiments, the predefined event until which the apparatus maintains the one or more CLTM cell switch preparation actions is at least one of: initiation / completion of cell switch based on reception of cell switch command or condition of CLTM cell switch becoming fulfilled, configuration of UE stopping CLTM condition evaluation for the candidate cell or RS configured for the candidate cell, or preconfigured / predefined time for preparation action maintenance expiring. In some embodiments, the one or more CLTM switch preparation actions are carried out by the apparatus in parallel, in series, or partially in parallel and partially in series.

[0214] In some embodiments, the apparatus further comprises means for receiving, from a network element of the mobile network, information about which of a plurality of CLTM switch preparation actions the apparatus is to perform. In some embodiments, the apparatus further comprises means for, in an instance in which the information about which of the plurality of CLTM cell switch preparation tasks the apparatus is to perform indicates that the apparatus is to perform only the one or more CLTM cell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks, initiating the one or more CLTM cell switch preparation tasks at the apparatus. In some embodiments, the apparatus further comprises means for, in an instance in which the information about which of the plurality of CLTM cell switch preparation tasks the apparatus is to perform indicates that the apparatus is to perform a subset of CLTM cell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks the subset of CLTM cell switch preparation tasks comprising the one or more CLTM cell switch preparation tasks for the CLTM cell switch to the particular candidate cell, initiating, at the UE, the subset of CLTM cell switch preparation tasks from among the plurality of CLTM cell switch preparation tasks.

[0215] In some embodiments, the apparatus further comprises means for receiving, from a network element of the mobile network, information about an order in which the apparatus is to perform the one or more CLTM switch preparation actions. In some embodiments, the apparatus further comprises means for, in an instance inwhich the information about the order in which the apparatus is to perform the one or more CLTM switch preparation actions indicates that all of the one or more CLTM switch preparation actions are to be performed in parallel, determining, based at least on a respective delay estimate for each of the one or more CLTM switch preparation actions, a total CLTM switch preparation delay estimate associated with the particular candidate cell to be a maximum delay estimate from among the respective delay actions for the one or more CLTM switch preparation actions. In some embodiments, the apparatus further comprises means for, in an instance in which the information about the order in which the apparatus is to perform the one or more CLTM switch preparation actions indicates that all of the one or more CLTM switch preparation actions are to be performed serially, determining, based at least on a sum of the respective delay estimates for the one or more CLTM switch preparation actions, a total CLTM switch preparation delay estimate associated with the particular candidate cell.

[0216] In some embodiments, the apparatus further comprises means for, in an instance in which the apparatus receives a cell switch command to perform a cell switch from a serving cell to the particular candidate cell or another candidate cell, determining that one or more required CLTM cell switch preparation tasks remain incomplete for the particular candidate cell or the another candidate cell, performing one or more incomplete required CLTM cell switch preparation tasks during cell switch. In some embodiments, the apparatus further comprises means for, in an instance in which the apparatus receives a cell switch command to perform a cell switch from a serving cell to the particular candidate cell or another candidate cell, determining that all required CLTM cell switch preparation tasks have been completed for the particular candidate cell or the another candidate cell, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0217] In some embodiments, the apparatus further comprises means for, in an instance in which a CLTM cell switch to the particular candidate cell is triggered based upon a CLTM condition associated with the particular candidate cell being met, determining whether the CLTM cell switch is being triggered before completion of one or more required CLTM cell switch preparation tasks for the particular candidate cell. In some embodiments, the apparatus further comprises means for, in an instance in which one or more required CLTM cell switch preparation tasks are incomplete, performing one or more incomplete required CLTM cell switch preparation tasks during CLTM cell switch to the particular candidate cell. In some embodiments, the apparatus further comprises means for, in an instance in which the one or more required CLTM cell switch preparation tasks are complete, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0218] According to another embodiment, a UE can be provided that comprises at least one processor and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the UE to perform, in an instance in which the UE is configured with one or more Conditional Layer 1 / Layer 2 Triggered Mobility (CLTM) conditions for initiating a CLTM cell switch to one or more candidate cells in a mobilenetwork, initiating monitoring for the one or more CLTM conditions for CLTM cell switch associated with the respective cells of the one or more candidate cells. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform initiating CLTM cell switch preparation tasks for the CLTM cell switch to respective candidate cells of the one or more candidate cells. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform determining whether at least one CLTM condition of the one or more CLTM conditions is satisfied, the at least one CLTM condition being conditions for CLTM cell switch to a particular network. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the at least one CLTM condition associated with the particular candidate cell is satisfied, determining whether the CLTM cell switch preparation tasks for the CLTM cell switch to the particular candidate cell are complete. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are incomplete, performing one or more incomplete required CLTM cell switch preparation tasks during cell switch. In some embodiments, the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are complete, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0219] According to another embodiment, a method can be carried out by means, such as a UE, that comprises, in an instance in which the UE is configured with one or more Conditional Layer 1 / Layer 2 Triggered Mobility (CLTM) conditions for initiating a CLTM cell switch to one or more candidate cells in a mobile network, initiating monitoring, using the UE, for the one or more CLTM conditions for CLTM cell switch associated with the respective cells of the one or more candidate cells. In some embodiments, the method can further comprise initiating, at the UE, CLTM cell switch preparation tasks for the CLTM cell switch to respective candidate cells of the one or more candidate cells. In some embodiments, the method can further comprise determining whether at least one CLTM condition of the one or more CLTM conditions is satisfied, the at least one CLTM condition being conditions for CLTM cell switch to a particular network. In some embodiments, the method can further comprise, in an instance in which the at least one CLTM condition associated with the particular candidate cell is satisfied, determining whether the CLTM cell switch preparation tasks for the CLTM cell switch to the particular candidate cell are complete. In some embodiments, the method can further comprise, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are incomplete, performing one or more incomplete required CLTM cell switch preparation tasks during cell switch. In some embodiments, the method can further comprise, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are complete,completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0220] According to another embodiment, a computer program product can be provided that comprises, e.g., a non-transitory computer-readable storage medium comprising instructions stored thereon that, when executed by at least one processor of a UE, cause the UE to perform, in an instance in which the UE is configured with one or more Conditional Layer 1 / Layer 2 Triggered Mobility (CLTM) conditions for initiating a CLTM cell switch to one or more candidate cells in a mobile network, initiating monitoring, using the UE, for the one or more CLTM conditions for CLTM cell switch associated with the respective cells of the one or more candidate cells. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform initiating, at the UE, CLTM cell switch preparation tasks for the CLTM cell switch to respective candidate cells of the one or more candidate cells. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform determining whether at least one CLTM condition of the one or more CLTM conditions is satisfied, the at least one CLTM condition being conditions for CLTM cell switch to a particular network. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which the at least one CLTM condition associated with the particular candidate cell is satisfied, determining whether the CLTM cell switch preparation tasks for the CLTM cell switch to the particular candidate cell are complete. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are incomplete, performing one or more incomplete required CLTM cell switch preparation tasks during cell switch. In some embodiments, the instructions stored thereon, when executed by the at least one processor, further cause the UE to perform, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are complete, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0221] According to another embodiment, an apparatus can be provided that comprises means for performing some or all portions of a method. The means can comprise, e.g., a processor and a memory storing instructions thereon that, when executed by the processor, cause the apparatus to perform some or all portions of the method. In some embodiments, the apparatus can comprise means for, in an instance in which the UE is configured with one or more Conditional Layer 1 / Layer 2 Triggered Mobility (CLTM) conditions for initiating a CLTM cell switch to one or more candidate cells in a mobile network, initiating monitoring, for the one or more CLTM conditions for CLTM cell switch associated with the respective cells of the one or more candidate cells. In some embodiments, the apparatus can further comprise means for initiating CLTM cell switch preparation tasks for the CLTM cell switch to respective candidate cells of the one or more candidate cells. In some embodiments, the apparatus can further comprise means for determining whether at least one CLTMcondition of the one or more CLTM conditions is satisfied, the at least one CLTM condition being conditions for CLTM cell switch to a particular network. In some embodiments, the apparatus can further comprise means for, in an instance in which the at least one CLTM condition associated with the particular candidate cell is satisfied, determining whether the CLTM cell switch preparation tasks for the CLTM cell switch to the particular candidate cell are complete. In some embodiments, the apparatus can further comprise means for, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are incomplete, performing one or more incomplete required CLTM cell switch preparation tasks during cell switch. In some embodiments, the apparatus can further comprise means for, in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are complete, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

[0222] Accordingly, blocks of the flowcharts support combinations of means for performing the specified functions and combinations of operations for performing the specified functions. It will also be understood that one or more blocks of the flowcharts, and combinations of blocks in the flowcharts, can be implemented by special purpose hardware-based computer systems which perform the specified functions, or combinations of special purpose hardware and computer instructions.

[0223] Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe example embodiments in the context of certain example combinations of elements and / or functions, it should be appreciated that different combinations of elements and / or functions may be provided by alternative embodiments without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and / or functions than those explicitly described above are also contemplated as may be set forth in some of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

Claims1. A user equipment (UE) comprising: at least one processor; and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the UE to perform at least: receiving a Layer 1 / Layer 2 triggered mobility (LTM) configuration associated with one or more candidate cells, wherein the UE is configured to initiate a Conditional LTM (CLTM) cell switch to at least one candidate cell based upon at least one CLTM condition being satisfied; initiating monitoring of the at least one CLTM condition for CLTM cell switch to the at least one candidate cell or at least one reference signal (RS) configured for the at least one candidate cell; based on initiating the monitoring of the at least one CLTM condition for CLTM cell switch, initiating one or more CLTM cell switch preparation actions for the at least one candidate cell or the at least one RS configured for the at least one candidate cell; after completion of performance of the one or more CLTM cell switch preparation actions, maintaining the one or more CLTM cell switch preparation actions until a predefined event, and in an instance in which a cell switch is initiated after completion of performance of the one or more CLTM cell switch preparation actions and before occurrence of a predefined event other than initiation or completion of the cell switch, completing the cell switch within a cell switch delay period that does not comprise one or more cell switch delay subperiods associated with the one or more CLTM cell switch preparation actions.

2. The UE of any prior claim, wherein the one or more CLTM cell switch preparation actions comprise at least one of: monitoring fine downlink timing for the particular candidate cell, monitoring frequency synchronization for the particular candidate cell, monitoring fine downlink timing for a reference signal (RS) associated with the particular candidate cell, monitoring frequency synchronization for the RS associated with the particular candidate cell, ASN.1 decoding, ASN.1 validity check, storing a decoded configuration of the candidate cell at the UE, monitoring a path loss estimate associated with the RS associated with the particular candidate cell, performing timing advance (TA) delay estimation for the particular candidate cell, determining a delay for UE -based TA estimation for the particular candidate cell, or estimating path loss reference signal (PL-RS) delay for the particular candidate cell.

3. The UE of any prior claim, wherein the predefined event until which the UE maintains the one or more CLTM cell switch preparation actions is at least one of: initiation / completion of cell switch based on reception of cell switch command or condition of CLTM cell switch becoming fulfilled,configuration of UE stopping CLTM condition evaluation for the candidate cell or RS configured for the candidate cell, or preconfigured / predefined time for preparation action maintenance expiring.

4. The UE of any prior claim, wherein the one or more CLTM switch preparation actions are carried out by the UE in parallel, in series, or partially in parallel and partially in series.

5. The UE of any prior claim, wherein the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform: receiving, at the UE, from a network element of the mobile network, information about which of a plurality of CLTM switch preparation actions the UE is to perform at the initiation of the monitoring of the at least one CLTM condition for CLTM cell switch.

6. The UE of claim 5, wherein the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform: at the instance of receiving the information about which of a plurality of CLTM switch preparation actions to perform, initiation of the indicated CLTM cell switch preparation tasks in the received information.

7. The UE of any one of claims 1-4, wherein the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform: receiving, at the UE, from a network element of the mobile network, information about an order in which the UE is to perform the one or more CLTM switch preparation actions.

8. The UE of claim 7, wherein the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform: in an instance in which the information about the order in which the UE is to perform the one or more CLTM switch preparation actions indicates that all of the one or more CLTM switch preparation actions are to be performed in parallel, determining, at the UE, based at least on a respective delay estimate for each of the one or more CLTM switch preparation actions, a total CLTM switch preparation delay estimate associated with the particular candidate cell to be a maximum delay estimate from among the respective delay actions for the one or more CLTM switch preparation actions.

9. The UE of claim 8, wherein the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform: in an instance in which the information about the order in which the UE is to perform the one or moreCLTM switch preparation actions indicates that all of the one or more CLTM switch preparation actions are to be performed serially, determining, at the UE, based at least on a sum of the respective delay estimates for the one or more CLTM switch preparation actions, a total CLTM switch preparation delay estimate associated with the particular candidate cell.

10. The UE of any prior claim, wherein the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform: in an instance in which the UE receives a cell switch command to perform a cell switch from a serving cell to the particular candidate cell or another candidate cell, determining that one or more required CLTM cell switch preparation tasks remain incomplete for the particular candidate cell or the another candidate cell, completing the incomplete preparation tasks during the cell switch.

11. The UE of claim 10, wherein the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform: in an instance in which the UE receives a cell switch command to perform a cell switch from a serving cell to the particular candidate cell or another candidate cell, determining that all required CLTM cell switch preparation tasks have been completed for the particular candidate cell or the another candidate cell, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks .

12. The UE of any one of claims 1-10, wherein the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform: in an instance in which a CLTM cell switch to the particular candidate cell is triggered based upon a CLTM condition associated with the particular candidate cell being met, determining whether the CLTM cell switch is being triggered before completion of one or more required CLTM cell switch preparation tasks; and in an instance in which one or more required CLTM cell switch preparation tasks are incomplete, completing the one or more CLTM cell switch preparation tasks required for CLTM cell switch to the particular candidate cell during the cell switch.

13. The UE of claim 12, wherein the instructions stored on the at least one memory, when executed by the at least one processor, further cause the UE to perform: in an instance in which the one or more required CLTM cell switch preparation tasks are complete, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

14. A method performed by a user equipment (UE), the method comprising: receiving a Layer 1 / Layer 2 triggered mobility (LTM) configuration associated with one or more candidate cells, wherein the UE is configured to initiate a Conditional LTM (CLTM) cell switch to at least one candidate cell based upon at least one CLTM condition being satisfied; initiating monitoring of the at least one CLTM condition for CLTM cell switch to the at least one candidate cell or at least one reference signal (RS) configured for the at least one candidate cell; based on initiating the monitoring of the at least one CLTM condition for CLTM cell switch, initiating one or more CLTM cell switch preparation actions for the at least one candidate cell or the at least one RS configured for the at least one candidate cell; after completion of performance of the one or more CLTM cell switch preparation actions, maintaining the one or more CLTM cell switch preparation actions until a predefined event, and in an instance in which a cell switch is initiated after completion of performance of the one or more CLTM cell switch preparation actions and before occurrence of a predefined event other than initiation or completion of the cell switch, completing the cell switch within a cell switch delay period that does not comprise one or more cell switch delay subperiods associated with the one or more CLTM cell switch preparation actions.

15. A user equipment (UE) comprising: at least one processor; and at least one memory storing instructions thereon that, when executed by the at least one processor, cause the UE to perform at least: in an instance in which the UE is configured with one or more Conditional Layer 1 / Layer 2 Triggered Mobility (CLTM) conditions for initiating a CLTM cell switch to one or more candidate cells in a mobile network, initiating monitoring for the one or more CLTM conditions for CLTM cell switch associated with the respective cells of the one or more candidate cells; initiating CLTM cell switch preparation tasks for the CLTM cell switch to respective candidate cells of the one or more candidate cells; determining whether at least one CLTM condition of the one or more CLTM conditions is satisfied, the at least one CLTM condition being conditions for CLTM cell switch to a particular network; in an instance in which the at least one CLTM condition associated with the particular candidate cell is satisfied, determining whether the CLTM cell switch preparation tasks for the CLTM cell switch to the particular candidate cell are complete; in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are incomplete, completing the one or more CLTM cell switch preparation tasks during the cell switch; andin an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are complete, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks .

16. A method performed by a user equipment (UE), the method comprising: in an instance in which the UE is configured with one or more Conditional Layer 1 / Layer 2 Triggered Mobility (CLTM) conditions for initiating a CLTM cell switch to one or more candidate cells in a mobile network, initiating monitoring, using the UE, for the one or more CLTM conditions for CLTM cell switch associated with the respective cells of the one or more candidate cells; initiating, at the UE, CLTM cell switch preparation tasks for the CLTM cell switch to respective candidate cells of the one or more candidate cells; determining whether at least one CLTM condition of the one or more CLTM conditions is satisfied, the at least one CLTM condition being conditions for CLTM cell switch to a particular network; in an instance in which the at least one CLTM condition associated with the particular candidate cell is satisfied, determining whether the CLTM cell switch preparation tasks for the CLTM cell switch to the particular candidate cell are complete; in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are incomplete, completing the one or more CLTM cell switch preparation tasks during the cell switch; and in an instance in which the one or more CLTM cell switch preparation tasks for the CLTM switch to the particular candidate cell are complete, completing the cell switch within a cell switch delay period that does not comprise cell switch delay subperiods associated with the one or more CLTM cell switch preparation tasks.

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