Apparatus and method for communication

Abstract

Embodiments of the present disclosure provide a solution for determining a target transmit configuration indicator (TCI) state. In the solution, a terminal device receives, from a network device providing a first cell serving the terminal device, a Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) cell handover command for a second cell to be handed over at a future time instance; and delaying performing a cell handover to the second cell indicated by the LTM-based cell handover command based at least in part on the delay duration.

Description

Technical Field

[0001] The exemplary embodiments of this disclosure relate generally to the field of communication technology, and more particularly to devices and methods for performing cell handover based on layer 1 / layer 2 triggered mobility (LTM). Background Technology

[0002] To ensure communication continuity in wireless communication systems, various techniques have been proposed, such as cell handover. During cell handover, terminal equipment can switch between different cells. Furthermore, LTM (Limited Time Management) technology is used to implement cell handover. More specifically, user equipment (UE) can report measurement reports to network equipment, and the LTM process can be triggered by the network equipment. When the network equipment makes an LTM decision, it can send a cell switch command (CSC) to the terminal equipment. However, in some cases, communication conditions may deteriorate drastically. If this occurs, the CSC may not be successfully sent to the terminal equipment. Therefore, ensuring that the CSC is successfully sent to the terminal equipment and that the cell handover indicated by the CSC is correctly executed is a problem that needs to be solved. Summary of the Invention

[0003] Overall, the embodiments disclosed herein provide a solution for performing LTM-based cell handover.

[0004] In a first aspect, a terminal device is provided, the terminal device comprising: a processor configured to cause the terminal device to: receive from a network device serving a first cell of the terminal device a Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) cell handover command to a second cell to be handed over at a future time instance; and to delay the execution of the cell handover to the second cell indicated by the LTM-based cell handover command, at least in part based on a delay duration.

[0005] In a second aspect, a network device is provided, comprising: a processor configured to cause the network device to: send configuration information to a terminal device serving a first cell provided by the network device, the configuration information indicating at least one of the following: a delay duration, wherein the terminal device delays performing a cell handover to the second cell for a period of time after receiving a Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) cell handover command from a second cell; a time window for enabling the function of delaying the cell handover; a first indication for enabling or disabling the function of delaying the cell handover; or a second indication for enabling or disabling mobility prediction function at the terminal device; and send the Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) cell handover command from the second cell to the terminal device.

[0006] In a third aspect, a communication method performed by a terminal device is provided. The method includes: receiving from a network device serving a first cell of the terminal device a Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) cell handover command for a handover to a second cell at a future time instance; and delaying the execution of the cell handover to the second cell indicated by the LTM-based cell handover command, at least in part based on a delay duration.

[0007] In a fourth aspect, a communication method performed by a network device is provided. The method includes: sending configuration information to a terminal device serving a first cell provided by the network device, the configuration information indicating at least one of the following: a delay duration, wherein the terminal device delays performing a cell handover to the second cell for a period of time after receiving a Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) cell handover command from a second cell; a time window for enabling the delayed cell handover function; a first indication for enabling or disabling the delayed cell handover function; or a second indication for enabling or disabling mobility prediction functionality at the terminal device; and sending the Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) cell handover command from the second cell to the terminal device.

[0008] In a fifth aspect, a computer-readable medium is provided that stores instructions which, when executed on at least one processor, cause the at least one processor to perform the method according to the third or fourth aspect.

[0009] Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0010] The above and other objects, features and advantages of this disclosure will become more apparent from a more detailed description of some exemplary embodiments thereof in the accompanying drawings, wherein: Figure 1A The signaling flow of the LTM process is illustrated; Figure 1B The graph illustrates the channel quality. Figures 1C to 1E The signaling flow of the communication is illustrated; Figure 2A An example communication environment in which an example implementation of the present disclosure can be carried out is illustrated; Figure 2B A block of the example model is shown; Figure 3A Signaling flows of communications according to some example embodiments of this disclosure are illustrated; Figure 3B Graphs illustrating channel quality according to some example embodiments of this disclosure are shown; Figure 4 Signaling flows of communications according to some example embodiments of this disclosure are illustrated; Figure 5A Predictive timing blocks according to some example embodiments of this disclosure are illustrated; Figures 5B to 5D Signaling flows of communications according to some example embodiments of this disclosure are illustrated; Figure 6 Signaling flows of communications according to some example embodiments of this disclosure are illustrated; Figures 7A to 7B Signaling flows of communications according to some example embodiments of this disclosure are illustrated; Figure 8A The prediction process blocks according to some example embodiments of this disclosure are illustrated; Figure 8B Signaling flows of communications according to some example embodiments of this disclosure are illustrated; Figure 9 Signaling flows of communications according to some example embodiments of this disclosure are illustrated; Figure 10 Flowcharts illustrating methods implemented at a terminal device according to some example embodiments of this disclosure are shown; Figure 11 Flowcharts illustrating methods implemented at a network device according to some example embodiments of this disclosure are shown; and Figure 12 A simplified block diagram of an apparatus suitable for implementing an example embodiment of the present disclosure is shown.

[0011] Throughout the accompanying drawings, the same or similar reference numerals denote the same or similar elements. Detailed Implementation

[0012] The principles of this disclosure will now be described with reference to some exemplary embodiments. It should be understood that these embodiments are described for illustrative purposes only and to help those skilled in the art to understand and implement this disclosure, and do not imply any limitation on the scope of this disclosure. The embodiments described herein can be implemented in various ways other than those described below.

[0013] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0014] As used herein, the term "terminal device" refers to any device with wireless or wired communication capabilities. Examples of terminal devices include, but are not limited to: User Equipment (UE); Personal Computers; Desktop Computers; Mobile Phones; Cellular Phones; Smartphones; Personal Digital Assistants (PDAs); Portable Computers; Tablets; Wearable Devices; Internet of Things (IoT) Devices; Ultra-reliable and Low-Latency Communication (URLLC) Devices; Internet of Everything (IoE) Devices; Machine-type Communication (MTC) Devices; Devices on vehicles for V2X communication, where X refers to pedestrians, vehicles, or infrastructure / networks; Devices for Integrated Access and Backhaul (IAB); Spacecraft or Aircraft Vehicles in Non-terrestrial Networks (NTNs), including satellites and High Altitude Platforms (HAPs) covering Unmanned Aircraft Systems (UAS); and different types of reality (such as Augmented Reality (AR), Mixed Reality (MR)). Extended Reality (XR) devices, including those for Virtual Reality (VR) and Virtual Reality (VR); unmanned aerial vehicles (UAVs), often referred to as drones (aircraft without human pilots); devices on high-speed trains (HSTs); or image capture devices such as digital cameras and sensors; gaming devices; music storage and playback equipment; or internet devices enabling wireless or wired internet access and browsing. "Terminal devices" may also have "multicast / broadcast" capabilities to support public safety and mission-critical applications, V2X applications, transparent IPv4 / IPv6 multicast delivery, IPTV, smart TV, radio services, wireless software delivery, group communication, and IoT applications. "Terminal devices" may also incorporate one or more Subscriber Identity Modules (SIMs), a situation known as multi-SIM. The term "terminal device" is used interchangeably with UE, mobile station, subscriber station, mobile terminal, user terminal, or wireless device.

[0015] The term "network device" refers to a device that provides or hosts a cell or coverage area for terminal devices to communicate. Examples of network devices include, but are not limited to, NodeBs (or NBs), evolved NodeBs (eNodeBs or eNBs), next-generation NodeBs (gNBs), transmission reception points (TRPs), remote radio units (RRUs), radioheads (RHs), remote radio heads (RRHs), IAB nodes, low-power nodes (such as femtonodes and piconodes), reconfigurable intelligent surfaces (RISs), etc.

[0016] Terminal devices or network devices may have artificial intelligence (AI) or machine learning capabilities. Terminal devices or network devices typically include models that have been trained on specific functions based on a large amount of collected data and can be used to predict some information.

[0017] Terminal or network devices can operate within several frequency ranges, such as FR1 (e.g., 450MHz to 6000MHz), FR2 (e.g., 24.25GHz to 71GHz), bands above 100GHz, and terahertz (THz). Terminal or network devices can also operate on licensed / unlicensed / shared spectrum. In Multi-Radio Dual Connectivity (MR-DC) applications, terminal devices can be connected to more than one network device. Terminal or network devices can operate in full-duplex, flexible-duplex, and cross-division duplex modes.

[0018] The embodiments of this disclosure can be executed in test equipment (e.g., signal generator, signal analyzer, spectrum analyzer, network analyzer, test terminal equipment, test network equipment, channel simulator). In some embodiments, the terminal equipment can be connected to a first network equipment and a second network equipment. One of the first network equipment and the second network equipment can be a master node, and the other can be a slave node. The first network equipment and the second network equipment can use different Radio Access Technologies (RATs). In some embodiments, the first network equipment can be a first RAT device, and the second network equipment can be a second RAT device. In some embodiments, the first RAT device is an eNB, and the second RAT device is a gNB. Information related to different RATs can be sent to the terminal equipment from at least one of the first network equipment or the second network equipment. In some embodiments, first information can be sent from the first network equipment to the terminal equipment, and second information can be sent from the second network equipment directly or via the first network equipment to the terminal equipment. In some embodiments, information configured by the second network equipment and related to the configuration of the terminal equipment can be sent from the second network equipment via the first network equipment. Information configured by the second network device and related to the reconfiguration of the terminal device can be sent directly from the second network device or via the first network device to the terminal device.

[0019] As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term “comprising” and its variations should be understood as open terms meaning “including, but not limited to.” The term “based on” should be understood as “at least partially based on.” The terms “one implementation” and “implementation” should be understood as “at least one implementation.” The term “another implementation” should be understood as “at least one other implementation.” The terms “first,” “second,” etc., may refer to different or the same objects. Other explicit and implicit definitions are given below.

[0020] In some examples, values, programs, or devices are described as “best,” “lowest,” “highest,” “smallest,” “maximum,” etc. It should be understood that such descriptions are intended to indicate that a choice can be made among many alternative functionalities used, and that such a choice is not necessarily better, smaller, higher, or otherwise preferred than other choices.

[0021] As used herein, the terms “resource,” “transmission resource,” “uplink resource,” or “downlink resource” can refer to any resource used to perform communication, such as a resource in the time domain, a resource in the frequency domain, a resource in the spatial domain, a resource in the code domain, or any other resource used to implement communication. In the following, unless explicitly stated otherwise, resources in both the frequency and time domains will be used as examples of transmission resources to describe some exemplary embodiments of this disclosure. It should be noted that the exemplary embodiments of this disclosure are equally applicable to other resources in other domains.

[0022] As discussed above, various techniques, such as cell handover, have been proposed to ensure communication continuity in wireless communication systems. During cell handover, terminal devices can switch between different cells. Furthermore, the LTM (Low-Terminal Mechanism) procedure is used to implement cell handover. Now refer to... Figure 1A The example illustrates the signaling flow 100A of the LTM process.

[0023] like Figure 1A As illustrated, during LTM preparation, the UE can send a Layer 1 (L1) measurement report to the source cell.

[0024] In some implementations, the L1 measurement report can be an L1-reference signal received power (L1-RSRP) measurement report based on the synchronization signal and physical broadcast channel (PBCH) block (SSB). Beam selection can be performed using such an SSB-based L1-RSRP measurement report.

[0025] In some implementations, beam selection can be performed across L cells from configured (or activated, if introduced) cells; that is, for each of the L cells, M beams are selected, where L and M are integers and L ≥ M. In some implementations, the parameters M and L can be configured for the UE in the measurement report configuration.

[0026] In some implementations, the UE can determine and select L cells and M beams per cell. In some implementations, M x L ​​beams can be reported in a single reporting instance. Furthermore, the maximum values ​​of M and L can be based on UE capabilities, and the UE capabilities support at least M x L ​​= 4. Additionally, reporting fewer than M x L ​​beams may or may not be permitted.

[0027] In some implementations, the following configurability can be introduced into the report configuration: whether the serving cell is always selected among the L cell selections performed by the UE, applicable when the UE is configured with L cells (L ≥ 2); whether at least one inter-frequency cell is always selected among the L inter-frequency cells among the L cell selections performed by the UE, applicable when the UE is configured with L cells (L ≥ 2) and at least one cell among the L inter-frequency cells is selected.

[0028] like Figure 1A As illustrated, early synchronization can be performed. In some implementations, at least downlink (DL) / uplink (UL) synchronization of candidate cells based on at least the SSB can be supported prior to a cell handover command.

[0029] In some implementations, for uplink (UL) synchronization, timing advance (TA) acquisition of candidate cells can be supported before the CSC is received in the LTM. Furthermore, when the candidate cell is a deactivated secondary cell, the application of this acquired TA to that candidate cell may or may not be permitted.

[0030] In some implementations, both RACH-based and RACH-free solutions can be used to obtain the TA of a candidate cell. For RACH-based solutions, the RACH can be a RACH indicated by the physical downlink control channel (PDCCH), a UE-triggered RACH, or a RACH triggered by the network via a higher layer instead of a Layer 3 handover command. For RACH-free solutions, the following procedures can be introduced: TA acquisition based on the sounding reference signal (SRS), TA acquisition based on the receiving timing difference (RX), RACH-free mechanisms such as those in LTE, and UE-based TA measurement (including UE-based TA measurement utilizing a timing advance command (TAC) from the serving cell).

[0031] In some implementations, for RACH indicated by PDCCH in LTE, at least the following enhancements are supported: introducing indication of candidate cells and / or RACH occasion (RO) of candidate cells in DCI; providing configuration of RACH resources for candidate cells before PDCCH indication.

[0032] exist Figure 1A In this context, early TCI activation can be performed. For example... Figure 1A As illustrated, a MAC CE can be used prior to CSC for TCI state activation for candidate cells. In some implementations, during the Release 18 LTM process, it is not supported to activate TCI states and candidate cell beam indications with the same MAC CE message in order to activate multiple joint TCI states or / and multiple pairs (DL / UL) TCI states for candidate cell scenarios.

[0033] exist Figure 1A In this process, the source cell can transmit a CSC to the UE to trigger the LMT procedure. In some implementations, the CSC may include at least the following information: information for identifying the target cell, TA-related information, and a combined or paired UL and DL unified TCI state index for the target cell. Furthermore, in some implementations, the CSC can be used to activate the bandwidth part (BWP) for the target cell. In some implementations, the beam indicator may be an RS identifier or a TCI state index.

[0034] In some implementations, to minimize beam (or TCI state) interruption time during handover (i.e., cell handover) in the LTM process, the source cell may use the transmitted CSC to indicate to the UE a set of activated TCI states for the target cell. Therefore, after handover, the UE can immediately apply the indicated TCI state for the target cell to effectively receive or transmit DL or UL signals on the target cell.

[0035] In summary, utilizing Figure 1A The LTM process can improve communication continuity. However, during the LTM process, radio link degradation occurs, especially in frequency range 2 (FR2) scenarios where the UE frequently experiences rapid degradation, such as... Figure 1B (As illustrated in graph 100B, which shows channel quality), sometimes the CSC may not be successfully transmitted to the UE. Further reference... Figure 1C This example illustrates signaling flow 100C for sending CSC.

[0036] like Figure 1C As illustrated, there is a time gap between the reported measurement results and the received CSC, and the channel quality may experience rapid degradation during this time gap. In such cases, this time gap can affect mobility robustness, especially in high-dynamic channels.

[0037] Generally, network devices only send LTM commands (e.g., CSC, which is MAC CE) to the UE when a cell handover is required. This means that the UE will perform a cell handover immediately after successfully receiving the CSC. However, in reality, due to poor channel quality, the UE may not successfully receive the CSC (e.g., ...). Figure 1D and Figure 1E (As illustrated), this will result in longer downtime.

[0038] If the CSC cannot be successfully sent to the terminal device due to deteriorated communication conditions, the communication interruption time will be longer. Therefore, ensuring that the CSC can be successfully sent to the terminal device and that cell handover can be performed correctly is the problem that needs to be solved.

[0039] According to this disclosure, a solution for performing LTM-based cell handover is proposed. In this solution, a terminal device receives an LTM-based cell handover command (CSC) from a network device serving a first cell (such as a serving cell) to which it will hand over to a second cell (such as a target / candidate cell) at a future time instance; and the execution of the cell handover to the second cell indicated by the LTM-based cell handover command is delayed, at least in part based on the delay duration.

[0040] In this way, LTM-based CSCs can be sent to the terminal device when communication conditions have not deteriorated significantly, thus ensuring successful CSC delivery. Furthermore, by delaying the handover to the second cell, it is ensured that the handover can be performed at the appropriate time instance.

[0041] For ease of discussion, the following list of some terms used in the following description is provided: Measurement reports / results may include, but are not limited to, L1 / L3-RSRP, L1 / L3-SINR (signal to interference plus noise ratio), L1 / L3-RSSI (received signal strength indication), and L1 / L3-RSRQ (reference signal receiving quality). This disclosure is not limited thereto. First cell: can refer to the serving cell. Sometimes it is also called the source cell. Therefore, the terms "first cell," "serving cell," and "source cell" are used interchangeably. Second cell: can refer to a candidate cell that is in / configured by the source cell and is different from the source cell. Therefore, the terms "second cell", "candidate cell" and "target cell" are used interchangeably; in addition, the target cell can be a candidate cell that is in / configured by the serving cell and can be different from the serving cell.

[0042] Beam: This can correspond to a channel state information-reference signal (CSI-RS), a synchronization signal, and a physical broadcast channel (PBCH) block (SSB), a CSI-RS resource, or an SSB resource. Therefore, the beam identifier (ID) can be a CSI-RS resource indicator (CRI), an SSB resource indicator (SSBRI), or an RSID. It should also be understood that, in fact, a beam refers to a resource that enables space-oriented communication, and therefore can be identified by other suitable parameters in other embodiments. This disclosure is not limited thereto. Furthermore, a beam can refer to a type D quasico-location (QCL) source RS, a spatial domain filter, or a UL transmitting (TX) spatial filter; Performing LTM may include at least one of the following: (MAC entity) indicates to the upper layer that it has received an LTM command (triggering the LTM cell handover process); (MAC entity) indicates to the upper layer the target configuration ID (i.e., the candidate cell indicator of the target cell) included in the LTM command. (MAC entity) processes the received timing advance command (i.e., TA information in the LTM command). (MAC entity) instructs the upper layer to skip the random access procedure for handover to this LTM cell; (MAC entity) indicates information to lower layers regarding the TCI status information included in the LTM command; Apply the TCI status information in the LTM command; Apply the TA information in the LTM command; Switch to the target configuration ID included in the LTM command; CSC can be a MAC CE used as an LTM command; L1 metrics may include at least one of L1-RSRP and L1-SINR; L3 metrics may include at least one of RSRP, SINR, RSSI, and block error rate (BLER). L1 / L3 Measurement Report: May refer to measurements and / or reports based on L1 / L3 metrics; Delayed LTM is a short expression. In reality, it can refer to a process: the UE delays the execution of LTM as instructed by the LTM command; LTM delay is just a short expression. In reality, it refers to the time delay required for LTM. Model inference: refers to the process of using a trained AI / ML model to produce a set of outputs based on a set of inputs; Quasi-Co-addressable (QCL)-Type: Can refer to QCL-TypeA, QCL-TypeB, QCL-TypeC, or QCL-TypeD. For example, QCL-TypeD refers to a qcl-Type set to "typeD". Source reference signal (RS): This refers to the reference signal configured in the TCI state. Furthermore, in QCL-TypeD, the source RS refers to the reference signal associated with typeD. Measurement reports include reports and / or measurement results.

[0043] In the context of this disclosure, The terms “LTM”, “LTM procedure”, “cell handover”, “transfer”, “cell addition”, “cell modification”, and “LTM-based cell handover” are used interchangeably. The terms “performing LTM”, “performing LTM cell handover”, and “applying CSC” are used interchangeably. The terms “delay,” “postponement,” “extension,” “suspension,” and “waiting” are used interchangeably. The terms "information," "field," and "configuration" are used interchangeably. The terms “cell”, “candidate cell”, “candidate / target (cell) configuration”, “bandwidth portion, BWP”, “downlink BWP”, “uplink BWP”, “cell ID / index / identifier”, “physical cell identifier, PCI”, and “candidate cell identifier” are used interchangeably; an example of a candidate cell identifier could be LTM-CandidateId-r18. The terms “AI / ML related functions”, “AI / ML enabled features (i.e., features that can use AI / ML)”, “AI / ML enabled feature groups”, “meta / auxiliary information”, and “applicable conditions” are used interchangeably. The terms “AI / ML”, “AI / ML model”, and “model” are used interchangeably and refer to data-driven algorithms that apply AI / ML technology to generate a set of outputs based on a set of inputs. The terms “instruction,” “trigger,” “activation,” “include,” “enable,” “initiate,” and “configuration” are used interchangeably. The terms "forecast time" and "forecast window" are used interchangeably; The terms “LTM command”, “CSC”, and “LTM-based CSC” are used interchangeably. The terms “disable,” “deactivate,” “release,” “ignore,” and “omit” are used interchangeably.

[0044] The principles and specific implementations of this disclosure will now be described in detail with reference to the accompanying drawings.

[0045] Example Environment Figure 2A An example communication environment 200A in which an example embodiment of the present disclosure may be implemented is shown. Network communication 200 includes terminal device 210, network device 220-1, and optional network device 220-2. Hereinafter, network devices 220-1 and 220-2 are collectively referred to as network device 220 or individually as network device 220. Additionally, network device 220 can provide one or more coverage areas (also referred to as cells).

[0046] As illustrated in Figure 2, the communication environment 200 includes cell 230-1 and cell 230-2. In the following text, cell 230-1 and cell 230-2 may be collectively referred to as cell 230 or individually referred to as first cell 230-1 and second cell 230-2.

[0047] In some implementations, both the first cell 230-1 and the second cell 230-2 may be provided by network device 220-1. In other implementations, the first cell 230-1 and the second cell 230-2 may be provided by network device 220-1 and network device 230-2, respectively.

[0048] In communication environment 200A, the link from terminal device 210 to network device 220 is called the uplink, and the link from network device 220 to terminal device 210 is called the downlink. In the downlink, network device 220 is the transmitting (TX) device (or sender), and terminal device 210 is the receiving (RX) device (or receiver). In the uplink, terminal device 210 is the TX device (or sender), and network device 220 is the RX device (or receiver).

[0049] In addition, Figure 2A In the example, terminal device 210 can move over time. For example... Figure 2A As illustrated, terminal device 210 is located at different locations at different times (T1 and T2). When terminal device 210 moves, it can switch between different cells 230.

[0050] In some implementations, network device 220-1 and network device 220-1 can communicate with each other via Xn messages.

[0051] Furthermore, the model can be deployed at terminal device 210 and / or network device 220. Now refer to Figure 2B This exemplifies block 200B of the example model.

[0052] like Figure 2B As illustrated, the measurement results (i.e., data samples) at each historical measurement time instance can be the measurement results of a beam set associated with the candidate cell set (e.g., L1-RSRP, L1-SINR).

[0053] For target cell prediction, the output at each future time instance can be an indicator of the target cell and the handover time to the target cell. For time L1 / L3 metric prediction, the output at each future time instance (in a set of future time instances) can be the predicted L1-RSRP / L1-SINR of the beam set associated with the candidate cell set.

[0054] Alternatively, the output at each future time instance (in a set of future time instances) can be a prediction indicator for the target cell and an optional prediction L1-RSRP / L1-SINR for the beam set associated with the target cell.

[0055] It should be understood that Figure 2AThe number of devices and their connections shown are given for illustrative purposes only and do not imply any limitation on this disclosure. The communication environment 200A may include any suitable number of network devices and / or terminal devices and / or coverage areas for implementing specific embodiments of this disclosure.

[0056] The communications in the communication environment 200A can conform to any suitable standard, including but not limited to Global System for Mobile Communication (GSM), Long Term Evolution (LTE), LTE-Evolution, LTE-Advanced (LTE-A), New Radio (NR), Wideband Code Division Multiple Access (WCDMA), Code Division Multiple Access (CDMA), GSM EDGE Radio Access Network (GERAN), Machine Type Communication (MTC), etc. The embodiments of this disclosure can be implemented according to any generation of communication protocols currently known or to be developed in the future. Examples of communication protocols include, but are not limited to, first-generation (1G), second-generation (2G), 2.5G, 2.75G, third-generation (3G), fourth-generation (4G), 4.5G, fifth-generation (5G), 5.5G, 5G-Advanced Networks, or sixth-generation (6G) networks.

[0057] Working principles and example signaling for communication refer to Figures 3A to 9 These diagrams will be referenced Figure 2A For example, we can use terminal device 210, network device 220, first cell 230-1 and second cell 230-2 for discussion.

[0058] In the following description, although operations are depicted in a specific order, this should not be construed as requiring such operations to be performed in the specific order shown or in sequential order, or to perform all the illustrated operations to achieve the desired result. In some environments, multitasking and parallel processing can be advantageous. While several specific implementation details are included in the foregoing discussion, these details should not be construed as limiting the scope of this disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features described in the context of individual embodiments may also be implemented in a single embodiment in combination. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0059] It should be understood that the operations at terminal device 210 and network device 220 should be coordinated. In other words, network device 220 and terminal device 210 should have a common understanding regarding configuration, parameters, etc. This common understanding can be achieved through any suitable interaction between network device 220 and terminal device 210, or by both network device 220 and terminal device 210 applying the same rules / policies. Although some operations are described below from the perspective of terminal device 210, it should be understood that the corresponding operations should be performed by network device 220. Similarly, although some operations are described from the perspective of network device 220, it should be understood that the corresponding operations should be performed by terminal device 210. For the sake of brevity, some identical or similar content is omitted here.

[0060] In addition, as described below, some interactions (such as configuration exchange) are performed between terminal device 210 and network device 220. It should be understood that these interactions can be implemented in a single signaling / message / configuration or in multiple signaling / message / configurations (including system information, radio resource control (RRC) messages, downlink control information (DCI) messages, uplink control information (UCI) messages, media access control (MAC) control elements (CE), etc.). This disclosure is not limited thereto.

[0061] In the example implementation below, terminal device 210 is served by a first cell 230-1. Furthermore, a second cell 230-2 is a candidate cell for terminal device 210. Therefore, the first cell 230-1 is referred to as source cell 230-1 or serving cell 230-1, and the second cell 230-2 is referred to as candidate cell 230-2 and target cell 230-2.

[0062] Furthermore, in some implementations, both the first cell 230-1 and the second cell 230-2 may be provided by network device 220-1. In some other implementations, the first cell 230-1 and the second cell 230-2 may be provided by network device 220-1 and network device 230-2, respectively.

[0063] As discussed above, AI / ML technology has been introduced, so terminal device 210 / network device 220 can predict when the terminal device will switch to the second cell (or when communication conditions will deteriorate).

[0064] Now for reference Figure 3A and Figure 3B These two figures illustrate, respectively, the signaling flow and channel quality curves 300B of a communication 300A according to some example embodiments of the present disclosure.

[0065] like Figure 3A As illustrated, based on AI / ML technologies (e.g., target cell prediction, time L1 / L3 metric prediction), network device 220 can know when a handover to the target cell is needed in the future. Therefore, when the channel quality of the first cell 230-1 (i.e., the source / serving cell) is good, the LTM command can be transmitted to terminal device 210 in advance.

[0066] For terminal device 210, when it successfully receives the LTM command, terminal device 210 may not immediately (or normally) perform cell handover, but will perform cell handover after a period of time (i.e., a specific time period, which is referred to as the delay duration below).

[0067] Now for reference Figure 4 This illustrates a signaling flow 400 of communication according to some example embodiments of the present disclosure.

[0068] exist Figure 4 In this context, terminal device 210 receives an LTM-based cell handover command from network device 220 providing services to the first cell 230-1, indicating that the handover will take place at a future time instance in the second cell 230-2. For example... Figure 4As illustrated, terminal device 210 delays the execution of cell handover to second cell 230-2 as indicated by the LTM-based cell handover command, at least in part, based on the delay duration, rather than immediately executing the cell handover to second cell 230-2.

[0069] In some implementations, the value of the delay duration can be determined based on machine learning (ML) related information.

[0070] Now for reference Figure 5A This illustrates a predictive timing block 500A according to some example embodiments of the present disclosure.

[0071] exist Figure 5A In this process, the latency duration can be determined based on AI / ML related information. In some implementations, the AI / ML related information may include the prediction time. The latency duration can be determined based on the prediction time. A diagram illustrating the prediction time is shown below; the prediction time can be as follows... Figure 5A The T1 or T2 shown refers to the time interval between a measurement / reporting time instance and a future time instance, or between two future time instances.

[0072] Furthermore, the predicted time can be included in the AI / ML related information exchanged between network device 220 and terminal device 210. Specifically, if the AI / ML model is located at terminal device 210, terminal device 210 can report UE capabilities containing AI / ML related information including the predicted time. Alternatively, if the AI / ML model is located at network device 220, network device 220 can send signaling to terminal device 210 indicating that AI / ML related information including the predicted time is included.

[0073] In addition to determining the latency duration based on AI / ML related information, in some implementations, the latency duration value can be configured to a default value. Alternatively, in some implementations, the latency duration value can be configured by network device 220.

[0074] Besides the delay duration, other parameters used to delay the cell handover to the second cell 230-2 can also be set to default configuration. Alternatively, these parameters can be configured by network device 220. Specifically, terminal device 210 can receive configuration information from network device 220 (i.e., the first cell 230-1). Details on how to exchange configuration information will be discussed below.

[0075] In some implementations, the configuration information is included in one of the following: Radio Resource Control (RRC) signaling, Media Access Control (MAC) control element (CE), or Downlink Control Information (DCI).

[0076] Additionally, in some implementations, if configuration information is included in the DCI, the DCI may be carried on a physical downlink control channel (PDCCH) scrambled with a specific radio network temporary identifier (RNTI) or having a specific format.

[0077] In some implementations, the configuration information may indicate at least one of the following: Delay duration; The time window for enabling delayed cell handover; The first indication used to enable or disable the function of delaying cell handover; A second instruction for enabling or disabling the mobility prediction function at terminal device 210.

[0078] In some implementations, the duration of the delay may be represented by one of the following: The duration of the delay An index associated with the duration of the delay, or Predefined periodic multiples.

[0079] In some implementations, the configuration information may include a first field indicating a first indication and a second field indicating the duration of the delay. In this case, if the function of the first field indicating a delay in performing cell handover is disabled, the network device 220 may perform the following operations: Ignore the second field. At least a portion of the bits corresponding to the second field are reused as reserved bits. Set at least a portion of the bits corresponding to the second field to "0", or Set the value of the delay duration indicated by the second field to zero.

[0080] Therefore, if the function of delaying cell handover indicated by the first field is disabled, the terminal device 210 can perform the following operations: Ignore the second field. Assume that at least some of the bits corresponding to the second field are set to reserved bits. Assuming that at least some of the bits corresponding to the second field are "0", or Assume the value of the delay duration indicated by the second field is zero.

[0081] In some implementations, this configuration information may be included in at least one first message that is different from the LTM-based cell handover command. For example... Figure 4 As illustrated, network device 220 can send a first message 410 to terminal device 210.

[0082] Alternatively, this configuration information may be included in LTM-based cell handover commands.

[0083] To better understand the above process, please refer to Figures 5B to 5D Further discussion of some implementation schemes, these diagrams illustrate signaling flows 500B, 500C and 500D of communications according to some example implementation schemes of this disclosure.

[0084] exist Figure 5B When the LTM command is successfully received, the terminal device 210 may perform the LTM (i.e., cell handover) indicated by the LTM command after the delay duration.

[0085] Furthermore, upon receiving an LTM command, terminal device 210 needs to determine whether LTM needs to be delayed. In other words, network device 220 needs to notify or indicate to terminal device 210 that the cell handover indicated by the LTM command needs to be delayed.

[0086] Now for reference Figure 5C In this configuration, the signaling for enabling delayed LTM is separate from the LTM command (e.g., the LTM command in version 18, i.e., CSC). Specifically, this configuration information may be included in at least one first message that is different from the LTM-based cell handover command. In this way, network device 220 can notify terminal device 210 whether a delay is needed for the cell handover indicated by the LTM command.

[0087] In some implementations, at least one first message can be used to enable delayed LTM or AI / ML related functions (e.g., target cell prediction, time L1 / L3 metric prediction, model inference, etc.).

[0088] In some implementations, after successfully receiving the first message, if the terminal device 210 receives an LTM command (i.e., CSC), the terminal device 210 may delay the cell handover indicated by the LTM command.

[0089] In some implementations, the first message may also indicate a window, meaning that terminal device 210 may assume that delayed LTM or AI / ML-related functions are enabled during the indicated window. Specifically, after (successfully) receiving the first message, if terminal device 210 receives an LTM command during the indicated window, terminal device 210 will delay the cell handover indicated by the LTM command.

[0090] In some implementations, the first message may be RRC, MAC CE, or DCI. Alternatively, the first message may be a PDCCH scrambled by a specific RNTI (i.e., DCI) or a PDCCH with a specific DCI format, wherein the specific RNTI or DCI format is specific to or dedicated to delay LTM or AI / ML related functions.

[0091] In some implementations, a new field may be included in the first message. Additionally, the new field may occupy one bit; for example, a bit value of "1" indicates that Delayed LTM is enabled, while a bit value of "0" indicates that Delayed LTM is disabled.

[0092] Optionally, the new field occupies N (N>1) bits; for example, a bit value of "0" indicates that Delayed LTM is disabled. And each of the other bit values ​​indicates the delay duration, meaning that Delayed LTM is enabled.

[0093] When Delayed LTM is enabled, if it is determined that cell handover needs to be delayed, terminal device 210 may also need to determine the (corresponding) delay duration. In other words, network device 220 needs to notify or indicate the delay duration to terminal device 210.

[0094] It should be understood that information used to enable delayed LTM or AI / ML related functions and information used to indicate the duration of delay may be included in a single first message or two different first messages.

[0095] In some implementations, the delay duration can be explicitly and directly indicated by the at least one first message. In this way, the terminal device 210 can determine the delay duration.

[0096] As discussed above, the first message can indicate the delay duration by including a new field occupying N (N>1) bits; for example, a bit value of "0" indicates that delay LTM is disabled. And each of the other bit values ​​indicates the delay duration, meaning that delay LTM is enabled.

[0097] In some implementations, if the first message is an RRC, then the first message may indicate one of the following: The absolute (or actual) value of the delay duration, such as 10ms, 20ms, 100ms, or A value associated with the delay duration. This value can be a multiple of a predefined time (e.g., forecast period, RS resource (collection), or L1 / L3 measurement or reporting). The delay duration is determined based on the indicated value.

[0098] If the first message is MAC CE or DCI, then the first message may indicate one of the following: The absolute (or actual) value of the delay duration, such as 10ms, 20ms, 100ms.

[0099] An index associated with the delay duration, such as 0, 1, 2. This index is (pre)configured by network device 220 using RRC signaling.

[0100] A value associated with the delay duration. This value can be a multiple of a predefined time (e.g., forecast period, RS resource (collection), or L1 / L3 measurement or reporting). The delay duration is determined based on the indicated value.

[0101] Now for reference Figure 5D The signaling that enables Delayed LTM is included in the LTM command (e.g., the new LTM command introduced in version 19, which is different from the CSC in version 18).

[0102] In some implementations, new fields may be introduced compared to traditional LTM commands (i.e., CSC).

[0103] In some implementations, the LTM command may include at least one of the following fields: The first field indicates whether the LTM as instructed by the LTM command is delayed, or The second field indicates the duration of the delay.

[0104] Upon receiving an LTM command, terminal device 210 may determine, based on the information included in the LTM command, whether to delay the LTM indicated by the LTM command and the (corresponding) delay duration.

[0105] LTM commands can be RRC, MAC CE, or DCI. Additionally, LTM commands can include variable sizes and have at least one of the following fields: First field: This field indicates whether to delay the LTM indicated by the LTM command. The length of this field is 1 bit. If this field is set to 1, the terminal device 210 may delay the LTM indicated by the LTM command. Otherwise (i.e., this field is set to 0), the LTM indicated by the LTM command is not delayed. In this case, the LTM command is similar to the R18 LTM command (i.e., CSC), that is, the terminal device 210 shall execute the LTM indicated by the LTM command without an additional delay duration.

[0106] Second field: This field indicates the delay duration. The length of this field is N1 (N1>0) bits.

[0107] In some embodiments, the second field may indicate one of the following: The absolute (or actual) value of the delay duration, such as 10 ms, 20 ms, 100 ms.

[0108] An index associated with the delay duration, such as 0, 1, 2. This index is (pre-)configured by the network device 220 using RRC signaling.

[0109] A value associated with the delay duration. This value can be a multiple of a predefined time (e.g., prediction period, RS resource (set) or L1 / L3 measurement or report). The delay duration is determined based on the indicated value.

[0110] In some embodiments, if the LTM command includes both the first field and the second field, and if the first field is set to 0, the terminal device 210 (and / or the network device 220) may perform at least one of the following operations: Assume that all bits of the second field are set to 0; Assume that N2 (0 < N2 ≤ N1) of the most significant bits (MSB) or least significant bits (LSB) of the second field are considered reserved bits, and the remaining (N1 - N2) bits are set to zero; or Ignore the second field.

[0111] In the case where the LTM command includes the second field but does not include the first field, if all bits of the second field are set to 0, the terminal device 210 may assume that the delay duration is zero, which means that the cell handover indicated by the LTM command is not delayed. Otherwise, the terminal device 210 may delay the cell handover indicated by the LTM command based on the indicated delay duration.

[0112] In some implementations, in addition to the first and second fields, the LTM command may also include at least one of the following: Candidate cell indicator for the target cell Scheduled advance (TA) information, TCI Status ID Activity UL BWP ID, Activity DL BWP ID, Trigger the aperiodic tracking reference signal (TRS) transmitted from the target cell. Trigger the acquisition and reporting of Channel State Information (CSI) of the target cell to the target cell. Triggering the transmission of an aperiodic sounding reference signal (SRS) to the target cell, or Cell-radio network temporary identifier (C-RNTI).

[0113] Below, we will discuss more details about how to delay the cell handover to the second cell 230-2.

[0114] In some implementations, terminal device 210 may send feedback information of the LTM-based cell handover command to network device 220 at a second time instance. Then, terminal device 210 performs a cell handover to a second cell 230-2 at a third time instance, which is the first time slot following the period starting from the second time instance, and this period includes at least the delay duration.

[0115] Now for reference Figure 6 This illustrates a signaling flow 600 of communication according to some example embodiments of the present disclosure.

[0116] exist Figure 6 In this context, a new duration (e.g., delay duration) is introduced. Based on the defined delay duration, terminal device 210 / network device 220 can know when to start delaying the cell handover indicated by the LTM command, and when to start performing the cell handover indicated by the LTM command.

[0117] In addition, Figure 6In this context, T represents the delay duration, and the starting position of the delay duration T is the first time slot after time slot n+T', where T' can be zero or determined based on at least one of the following: Its pointer is configured for subcarrier spacing. The number of time slots per subframe, and Sometimes it can be 3ms. Beam application time, such as BeamAppTime-r17, Radio frequency (RF) retuning time.

[0118] like Figure 6 As shown, when terminal device 210 sends a PUCCH in time slot n containing HARQ-ACK information corresponding to the PDSCH carrying the LTM command, terminal device 210 can start executing the LTM indicated by the LTM command from the first time slot after time slot n + T + T'.

[0119] In some implementations, terminal device 210 may start a timer corresponding to the delay duration upon receiving an LTM-based cell handover command or upon receiving feedback information indicating that an LTM-based cell handover command has been sent. Then, when the timer expires, terminal device 210 may perform a cell handover to the second cell 230-2.

[0120] In some implementations, a new timer corresponding to the delay duration (e.g., a delay duration timer) may be introduced, such as Figure 7A As illustrated, this figure illustrates a signaling flow 700A of communications according to some example embodiments of this disclosure. Based on a defined delay duration timer, terminal device 210 / network device 220 can know when to start delaying the cell handover indicated by the LTM command, and when to start performing the cell handover indicated by the LTM command.

[0121] In some implementations, this configuration information is indicated via a first message, such as an RRC, instead of an LTM command. In this case, terminal device 210 (or MAC entity) may be configured with delayed LTM by an RRC (per serving cell). The RRC may be configured with at least one of a parameter indicating a delay duration timer or a parameter indicating an LTM window. If terminal device 210 (or MAC entity) receives an LTM command (or during an LTM window if one is configured), terminal device 210 may start or restart the delay duration timer and / or delay LTM (i.e., cell handover). If the delay duration timer expires, terminal device 210 may perform a cell handover.

[0122] For example, the first message could be a DCI. In this case, terminal device 210 (or MAC entity) can receive an indication from a lower layer regarding the delayed LTM and / or the delay duration. If terminal device 210 (or MAC entity) receives an LTM command, terminal device 210 can start or restart the delay duration timer and / or delay the LTM. If the delay duration timer expires, terminal device 210 can perform a cell handover.

[0123] In some implementations, this configuration information is indicated in the LTM command, such as Figure 7B As illustrated, this figure illustrates a signaling flow 700B of communication according to some example embodiments of this disclosure. In this case, if terminal device 210 (or MAC entity) (on the serving cell) receives an LTM command, and if the LTM command includes an indication of delayed LTM and / or delay duration, terminal device 210 may start or restart a delay duration timer, and / or delay LTM. If the delay duration timer expires, terminal device 210 may perform LTM.

[0124] In some cases, the performance of AI / ML models may be poor, leading to inaccurate predictions of the target cell or L1 / L3 metrics. This can result in incorrect LTM decisions, such as... Figure 8A As illustrated, this figure illustrates a prediction process block 800A according to some example embodiments of this disclosure. In view of this, measurements can be performed after receiving an LTM command, or during the delay duration, such as... Figure 8B The diagram illustrates a signaling flow 800B of communications according to some example embodiments of this disclosure. The measurement may be an (L1 / L3) measurement for the serving cell and / or the target cell. For example, the measurement resources used for the measurement (i.e., RSs configured for measurement reporting) may be transmitted from at least the target cell, and the measurement results are reported to the source cell. Based on this measurement, erroneous LTM decisions can be avoided.

[0125] Continue to refer to Figure 4 .like Figure 4 As illustrated, in order to ensure that the decision to send the LTM-based cell handover command is correct, after sending the LTM-based cell handover command, the terminal device 210 may perform a 450 measurement on at least one of the first cell 230-1 or the second cell 230-2, and the network device 220 may also receive a 460 measurement result from the terminal device 210.

[0126] In some implementations, terminal device 210 may perform measurements on at least one of the first cell 230-1 or the second cell 230-2 during the initial period of the delay duration.

[0127] In some implementations, terminal device 210 may send a measurement report to network device 220, wherein the measurement report may include measurement results of first cell 230-1 and / or second cell 230-2. In some implementations, the measurement report may be a periodic, semi-persistent, or non-periodic measurement report.

[0128] In some implementations, the measurement report may include at least one of the following: layer 1 or layer 3 measurement results of the first cell 230-1; or layer 1 or layer 3 measurement results of the second cell 230-2.

[0129] In some implementations, reporting measurement results may be event-triggered. In some implementations, terminal device 210 may determine that a predefined condition is met when at least one of the following is detected: The measurement quality of the second cell 230-2 is lower than or equal to the first threshold quality. The measurement quality of the second cell 230-2 is higher than or equal to the second threshold quality. The difference between the measurement quality of the second cell 230-2 and the measurement quality of the first cell 230-1 is greater than or equal to the third threshold quality. The difference between the measurement quality of the second cell 230-2 and the measurement quality of the first cell 230-1 is less than or equal to the third threshold quality. The difference between the measurement quality and the predicted quality of cell 230-2 is greater than or equal to the third threshold quality, or The difference between the measurement quality and the predicted quality of the second cell 230-2 is less than or equal to the third threshold quality.

[0130] In some implementations, based on the determination that predefined conditions are met, terminal device 210 may send a measurement report, which includes a third indication of the status of whether the predefined conditions triggering the measurement report are met. Alternatively, based on the determination that predefined conditions are met, terminal device 210 may send measurement information.

[0131] In some implementations, the measurement information may be associated with at least one of the following: The fourth instruction is used to stop the cell handover to the second cell 230-2 indicated by the LTM-based cell handover command, or to initiate the cell handover to the second cell 230-2; or A measurement report, which includes indications that predefined conditions are met; Measurement results of floor 1 or floor 3 of unit 230-1 in the first residential area; or Measurement results of floor 1 or floor 3 of the second community 230-2.

[0132] In some implementations, measurement information is indicated by the physical uplink control channel (PUCCH) associated with a dedicated scheduling request (SR).

[0133] In some implementations, terminal device 210 may send measurement information or a measurement report when it determines that the number of times a predefined condition is met is greater than or equal to a threshold number.

[0134] In some implementations, terminal device 210 may determine first measurement resources for measuring the first cell 230-1, including RS resources associated with the TCI state applied to the first cell 230-1.

[0135] Alternatively or in some embodiments, terminal device 210 may determine second measurement resources for measuring the second cell 230-2, including reference signal (RS) resources associated with the state of a transmission configuration indicator (TCI) indicated in an LTM-based cell handover command, wherein the TCI state will be applied to the second cell 230-2.

[0136] In some implementations, terminal device 210 may receive a measurement configuration from network device 220 before performing measurements on at least one of first cell 230-1 or second cell 230-2. Specifically, the measurement configuration may indicate the measurement resources that terminal device 210 will use to measure first cell 230-1 and / or second cell 230-2.

[0137] In some implementations, the measurement configuration may be included in an LTM-based cell handover command, or in at least one first message, or in at least one second message different from the LTM-based cell handover command (e.g., Figure 4As illustrated, network device 220 may send at least one second message 440 to terminal device 210, wherein the second message may include measurement configuration.

[0138] In some implementations, the measurement configuration may include at least one of the following: The third field indicates a set of parameters used to report measurement results; The fourth field indicates that the measurement result was sent to cell 230-1, or The fifth field indicates the measurement resources that will be used by the terminal device 210 to measure at least one of the first cell 230-1 or the second cell 230-2.

[0139] In some implementations, upon receiving the measurement results, network device 220 may send a third message 470 indicating a fifth indication to stop the cell handover to the second cell 230-2 indicated by the LTM-based cell handover command (i.e., network device 220 notices that terminal device 210 should not hand over to the second cell).

[0140] Alternatively, in some implementations, upon receiving the measurement results, network device 220 may send a third message 470 indicating a sixth indication for initiating a cell handover to the second cell 230-2 (i.e., the decision to delay the cell handover to the second cell is incorrect).

[0141] To better understand the above process, please refer to Figure 9 Further discussion of some example processes is provided, and the diagram illustrates the signaling flow 900 of communications according to some example implementations of this disclosure.

[0142] In some implementations, the measurement information / report may be triggered by an RRC, MAC CE, or DCI, which may be sent from network device 220 after an LTM command is sent. Optionally, the measurement information / report may be triggered by an LTM command (e.g., MAC CE). In this case, the LTM command may include at least one of the following fields: The third field. The third field can indicate measurement information / reports. In other words, terminal device 210 can determine configuration information related to the measurement report based on the information indicated by the third field. For example, the third field indicates the measurement report (e.g., LTM-CSI-ReportConfig ) associated indexes (e.g., LTM-CSI-ReportConfigId ).

[0143] The fourth field. The fourth field indicates the measurement information / report used to distinguish the measurement report (referred to as the "first measurement report") from another measurement report indicated by the LTM command (referred to as the "second measurement report").

[0144] Fifth field. The fifth field may indicate the measurement resource (e.g., SSB, CSI-RS resource) used for measurement reporting.

[0145] In some implementations, the fourth field may indicate whether the corresponding measurement report is reported to the source cell or the target cell. For example, the first measurement report may be reported to the source cell, and the second measurement report may be reported to the target cell. Additionally, this field may indicate whether the corresponding measurement report is executed during the delay duration.

[0146] In some implementations, the measurement resources used for the measurement report can be determined based on the triggered measurement report, such as the measurement resources associated with the measurement report triggered by network device 220. The measurement resources are indicated by at least one RRC, MACCE, or DCI (e.g., the fifth field in an LTM command).

[0147] In some implementations, the measurement resources used for measurement reports may be determined based on at least one predefined RS, such as a source RS associated with the TCI state indicated by an LTM command (e.g., a QCL-TypeD source RS) or a source RS associated with the TCI state applicable to a channel or RS transmitted in the source cell (e.g., a QCL-TypeD source RS). This implementation may be used when providing the terminal device 210 with the aforementioned measurement resources associated with the measurement report or measurement resources indicated by RRC / MAC CE / DCI.

[0148] In some implementations, the measurement report type can be periodic, semi-persistent, non-periodic, or event-triggered.

[0149] For event-triggered measurement reports / information, the terminal device 210 may report a measurement report / information when at least one predefined condition is met. In some embodiments, the at least one predefined condition includes at least one of the following: The measurement results of the target cell (i.e., the L1 / L3 metric corresponding to the measurement resources associated with the target cell) are less than (or greater than) the first threshold.

[0150] The difference between the measurement results of the target cell and the measurement results of the source cell is less than (or greater than) the second threshold.

[0151] If the difference between the measurement results of a set of measurement resources and the corresponding prediction results is greater than a third threshold, this condition indicates that the AI / ML model is performing poorly.

[0152] Additionally, in some implementations, terminal device 210 may report a measurement report / information when at least one predefined condition occurs consecutively more than or equal to a fourth threshold. For example, if at least one predefined condition is met, an indication is sent from a lower layer to a higher layer (e.g., the MAC layer). If the higher layer receives the indication from the lower layer, a predefined counter is incremented by 1. When terminal device 210 is indicated to have a measurement report, the predefined counter is initially set to 0. If the predefined counter is ≥ the fourth threshold, a measurement report / information may be triggered.

[0153] Furthermore, the terminal device 210 only needs to execute the measurement report for a certain duration within the delay duration, which can be indicated by RRC / MAC CE / DCI (e.g., LTM command). In some embodiments, the starting position of this duration can be the same as the starting position of the delay duration.

[0154] In some implementations, if the measurement report is periodic, semi-persistent, or event-triggered, the measurement report can be stopped based on its duration. For example, if the measurement duration (defined as a default value, configured by network device 220, or reported by terminal device 210) expires, terminal device 210 stops (or deactivates) the measurement result report. Additionally, a predefined counter is set to 0.

[0155] In some implementations, the measurement report may include at least one of the following: The L1 metric corresponding to the target cell and / or the source cell.

[0156] L3 metrics corresponding to the target cell and / or source cell.

[0157] A third indication. A third indication can be used to indicate a state. This state can be determined based on at least one predefined condition. For example, a third indication indicates whether at least one predefined condition is met.

[0158] In some implementations, measurement reports may be hosted by PUCCH or PUSCH resources.

[0159] Additionally, terminal device 210 may report a fourth indication to network device 220. For example, terminal device 210 may send a fourth indication to network device 220 when at least one predefined condition is met, or when the number of consecutive occurrences of at least one predefined condition exceeds or equals a fourth threshold. For example, the fourth indication may be a request to stop LTM, stop delayed LTM, or start (traditional) LTM. The fourth indication may be indicated by a PUCCH with the request, which is associated with a dedicated SR (i.e., dedicated...). schedulingRequestID (related to)

[0160] Based on the measurement results, network device 220 may notice that the target cell indicated by the LTM command may be incorrect (e.g., the quality of the target cell is not good enough, or the quality of the source cell is not good enough), or the timing of the handover to the target cell may be incorrect (e.g., LTM needs to be performed earlier than it should be performed after the delay duration expires). In this case, a new LTM decision can be generated to avoid erroneous LTM.

[0161] like Figure 9 As illustrated, network device 220 may send a third message to terminal device 210 during the delay duration, the third signaling being used for at least one of the following: disabling delay LTM; disabling (or ignoring) delay duration; triggering (traditional) LTM.

[0162] When an LTM decision corresponding to a delayed LTM is incorrect, a new LTM decision can be notified to terminal device 210 based on a third message to avoid erroneous cell handover. For example, the third message can be used to disable delayed LTM. If terminal device 210 (successfully) receives the third message, terminal device 210 can assume that delayed LTM is disabled, i.e., stop delayed LTM. Additionally, at least one of the following information activated by the most recent LTM command is deactivated (or ignored): delay duration, candidate cell indicator of the target cell, TA information, TCI status ID, active UL BWP ID, active DL BWP ID, triggering AP TRS sent from the target cell, triggering CSI acquisition of the target cell and reporting it to the target cell, triggering APSRS sent to the target cell, or C-RNTI.

[0163] For example, a third message can be used to disable the delay duration and trigger (traditional) LTM. In this case, if terminal device 210 (successfully) receives the third message, terminal device 210 can ignore the delay duration and execute the LTM indicated by the (most recent) LTM command. Information related to the LTM (e.g., target cell, TA information, TCI status ID, etc.) can be determined based on the (most recent) LTM command.

[0164] The third message can be RRC, MAC-CE, or DCI, and in addition, the third message may include a candidate cell indicator for the target cell.

[0165] Based on the above process, when communication conditions have not deteriorated significantly, the LTM-based CSC can be sent to the terminal device, thus ensuring that the CSC can be successfully sent to the terminal device. Furthermore, by delaying the cell handover to the second cell, it is ensured that the cell handover can be performed at the appropriate time instance.

[0166] Example Method Figure 10 A flowchart illustrating a communication method 1000 implemented at a terminal device according to some embodiments of the present disclosure is provided. For discussion purposes, [the following will be discussed]. Figure 2A Angle description method 1000 for terminal device 210 in the middle.

[0167] At box 1010, the terminal device receives a Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) cell handover command from a network device serving the first cell to which it will be handed over to a second cell at a future time instance.

[0168] At box 1020, the terminal device delays the execution of the cell handover to the second cell as indicated by the LTM-based cell handover command, at least in part, based on the delay duration.

[0169] In some example implementations, the processor is further configured to cause the terminal device to: receive configuration information from a first cell indicating at least one of the following: a delay duration; a time window for enabling delayed cell handover; a first indication for enabling or disabling delayed cell handover; a second indication for enabling or disabling mobility prediction at the terminal device; or a measurement configuration indicating measurement resources to be used by the terminal device to measure at least one of the following: the first cell or the second cell.

[0170] In some example implementations, the configuration information is included in the LTM-based cell handover command, or in at least one first message that is different from the LTM-based cell handover command.

[0171] In some example implementations, the configuration information is included in one of the following: Radio Resource Control (RRC) signaling, Media Access Control (MAC) control element (CE), or Downlink Control Information (DCI).

[0172] In some example implementations, the DCI is carried on a physical downlink control channel (PDCCH) scrambled with a specific radio network temporary identifier (RNTI) or having a specific format.

[0173] In some example implementations, the configuration information includes a first field for indicating a first indication and a second field for indicating the duration of a delay, wherein if the function of delaying cell handover indicated by the first field is disabled, the terminal device may ignore the second field, assuming that at least a portion of the bits corresponding to the second field are set to reserved bits, assuming that at least a portion of the bits corresponding to the second field are "0", or assuming that the value of the delay duration indicated by the second field is zero.

[0174] In some example implementations, the delay duration is represented by one of the following: the length of the delay duration, an index associated with the length of the delay duration, or a multiple of a predefined periodicity.

[0175] In some example implementations, the latency duration is configured by the network device, defined as a default value, or determined based on machine learning (ML) related information.

[0176] In some example implementations, the terminal device may send feedback information of an LTM-based cell handover command to the network device at a second time instance, and perform a cell handover to the second cell at a third time instance, which is a first time slot after the period starting from the second time instance, the period including at least the delay duration.

[0177] In some example implementations, the terminal device may start a timer corresponding to the delay duration when it receives an LTM-based cell handover command or sends feedback information of an LTM-based cell handover command; and when the timer expires, perform a cell handover to a second cell.

[0178] In some example implementations, after receiving an LTM-based cell handover command, the terminal device may perform measurements on at least one of the first or second cells.

[0179] In some example implementations, the terminal device may send a measurement report to the network device, the measurement report including measurement results of at least one of the following: a first cell or a second cell.

[0180] In some example implementations, the measurement reports are periodic, semi-permanent, or non-periodic.

[0181] In some example implementations, the measurement report includes at least one of the following: layer 1 or layer 3 measurement results of a first cell; layer 1 or layer 3 measurement results of a second cell; or a third indication of the status of whether predefined conditions for triggering the measurement report are met.

[0182] In some example implementations, based on the determination that predefined conditions are met, the terminal device may send measurement information to the network device regarding at least one of the following: a fourth indication for stopping a cell handover to a second cell indicated by an LTM-based cell handover command, or for initiating a cell handover to a second cell; or a measurement report including an indication that predefined conditions are met; a Layer 1 or Layer 3 measurement result of the first cell; or a Layer 1 or Layer 3 measurement result of the second cell.

[0183] In some example implementations, the terminal device may determine that a predefined condition is met when it detects at least one of the following: the measurement quality of the second cell is lower than or equal to a first threshold quality; the measurement quality of the second cell is higher than or equal to a second threshold quality; the difference between the measurement quality of the second cell and the measurement quality of the first cell is greater than or equal to a third threshold quality; the difference between the measurement quality of the second cell and the measurement quality of the first cell is less than or equal to a third threshold quality; the difference between the measurement quality of the second cell and the predicted quality of the second cell is greater than or equal to a third threshold quality; or the difference between the measurement quality of the second cell and the predicted quality of the second cell is less than or equal to a third threshold quality.

[0184] In some example implementations, measurement information is indicated by the Physical Uplink Control Channel (PUCCH) associated with a Dedicated Scheduling Request (SR).

[0185] In some example implementations, the terminal device may send measurement information or a measurement report when it determines that the number of times a predefined condition is met is greater than or equal to a threshold number.

[0186] In some example implementations, the terminal device may perform at least one of the following: determining first measurement resources for measuring a first cell, including RS resources associated with a TCI state applied to the first cell; or determining second measurement resources for measuring a second cell, including reference signal (RS) resources associated with a transmit configuration indicator (TCI) state indicated in an LTM-based cell handover command, wherein the TCI state will be applied to the second cell.

[0187] In some example implementations, before performing a measurement on at least one of the first cell or the second cell, the terminal device may receive a measurement configuration from the network device, wherein the measurement configuration indicates that the terminal device will use to measure a measurement resource of at least one of the following: the first cell or the second cell, and wherein the measurement configuration is included in an LTM-based cell handover command or in at least one second message different from the LTM-based cell handover command.

[0188] In some example implementations, the measurement configuration includes at least one of the following: a third field indicating a set of parameters for reporting measurement results; a fourth field indicating that the measurement results are sent to a first cell; or a fifth field indicating measurement resources that will be used by the terminal device to measure at least one of the first cell or the second cell.

[0189] In some example implementations, during the delay duration, the terminal device may receive a third message indicating at least one of the following: a fifth indication for stopping the cell handover to the second cell indicated by the LTM-based cell handover command, or a sixth indication for starting the cell handover to the second cell.

[0190] In some example implementations, the terminal device may perform measurements on at least one of the first cell or the second cell during the initial period of the delay duration.

[0191] In some example implementations, the first cell is the serving cell, and the second cell is the target cell.

[0192] Figure 11 A flowchart illustrating a communication method 1100 implemented at a network device according to some embodiments of this disclosure is shown. For discussion purposes, [the following will be discussed]. Figure 2A The angular description method of network device 220 in 1100.

[0193] At step 1110, the network device sends configuration information to a terminal device providing first cell services by the network device, the configuration information indicating at least one of the following: a delay duration, wherein the terminal device delays performing a cell handover to the second cell within the delay duration after receiving a Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) cell handover command from the second cell; a time window for enabling the function of delaying cell handover; a first indication for enabling or disabling the function of delaying cell handover; or a second indication for enabling or disabling mobility prediction functions at the terminal device.

[0194] At box 1160, the network device may send a cell handover command for the second cell based on Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) to the terminal device.

[0195] In some example implementations, the configuration information is included in the LTM-based cell handover command, or in at least one first message that is different from the LTM-based cell handover command.

[0196] In some example implementations, the configuration information is included in one of the following: Radio Resource Control (RRC) signaling, Media Access Control (MAC) control element (CE), or Downlink Control Information (DCI).

[0197] In some example implementations, the DCI is carried on a physical downlink control channel (PDCCH) scrambled with a specific radio network temporary identifier (RNTI) or having a specific format.

[0198] In some example implementations, the configuration information includes a first field for indicating a first indication and a second field for indicating the duration of a delay, wherein if the function of the first field indicating a delay in performing cell handover is disabled, the network device may ignore the second field, reuse at least a portion of the bits corresponding to the second field as reserved bits, set at least a portion of the bits corresponding to the second field to "0", or set the value of the delay duration indicated by the second field to zero.

[0199] In some example implementations, the delay duration is represented by one of the following: the length of the delay duration, an index associated with the length of the delay duration, or a multiple of a predefined periodicity.

[0200] In some example implementations, the latency duration is configured by the network device, defined as a default value, or determined based on machine learning (ML) related information.

[0201] In some example implementations, during the delay duration, the network device may receive a measurement report from the terminal device, the measurement report including measurement results of at least one of the following: a first cell or a second cell.

[0202] In some example implementations, measurement reports are periodic, semi-persistent, non-periodic, or event-triggered.

[0203] In some example implementations, the measurement report includes at least one of the following: layer 1 or layer 3 measurement results of a first cell; layer 1 or layer 3 measurement results of a second cell; or a third indication of the status of whether predefined conditions for triggering the measurement report are met.

[0204] In some example implementations, during the delay duration, the network device may receive trigger-based measurement information from the terminal device regarding at least one of the following: a fourth indication for stopping a cell handover to a second cell indicated by an LTM-based cell handover command, or for initiating a cell handover to a second cell; or a measurement report including an indication that predefined conditions are met; a Layer 1 or Layer 3 measurement result of the first cell; or a Layer 1 or Layer 3 measurement result of the second cell.

[0205] In some example implementations, the trigger-based measurement information is indicated by the Physical Uplink Control Channel (PUCCH) associated with the Dedicated Scheduling Request (SR).

[0206] In some example implementations, the network device may send measurement configurations associated with at least one of the first cell or the second cell to the terminal device.

[0207] In some example implementations, the measurement configuration indicates that the terminal device will use it to measure at least one of the following measurement resources: a first cell or a second cell, and wherein the measurement configuration is included in: an LTM-based cell handover command, configuration information, or at least one second message different from an LTM-based cell handover command.

[0208] In some example implementations, the LTM-based cell handover command includes at least one of the following: a third field indicating a set of parameters for reporting measurement results; a fourth field indicating that the measurement results are sent to a first cell; or a fifth field indicating that the terminal device will use the measurement resources to measure at least one of the first cell or the second cell.

[0209] In some example implementations, during the delay duration, the terminal device may send a third message indicating at least one of the following: a fifth indication for terminating the delayed cell handover to the second cell, or a sixth indication for initiating the cell handover to the second cell.

[0210] In some example implementations, the first cell is the serving cell, and the second cell is the target cell.

[0211] Example devices and apparatus Figure 12 This is a simplified block diagram of device 1200 suitable for implementing embodiments of this disclosure. Device 1200 can be considered as follows: Figure 2AAnother example implementation of any of the devices shown is provided. Therefore, device 1200 may be implemented at or be at least a part of terminal device 210 or network device 220.

[0212] As shown in the figure, device 1200 includes a processor 1210, a memory 1220 coupled to the processor 1210, a suitable transceiver 1240 coupled to the processor 1210, and a communication interface coupled to the transceiver 1240. The memory 1220 stores at least a portion of a program 1230. Depending on requirements, the transceiver 1240 can be used for bidirectional or unidirectional communication. The transceiver 1240 may include at least one of a transmitter 1242 and a receiver 1244. The transmitter 1242 and receiver 1244 may be functional modules or physical entities. The transceiver 1240 has at least one antenna to facilitate communication; however, in practice, the access node mentioned in this application may have several antennas. The communication interface can represent any interface necessary for communication with other network elements, such as the X2 / Xn interface for bidirectional communication between eNBs / gNBs, the S1 / NG interface for communication between the Mobility Management Entity (MME) / Access and Mobility Management Function (AMF) / SGW / UPF and eNBs / gNBs, the Un interface for communication between eNBs / gNBs and relay nodes (RNs), or the Uu interface for communication between eNBs / gNBs and terminal equipment.

[0213] Assume that program 1230 includes program instructions that, when executed by the associated processor 1210, enable device 1200 to operate according to embodiments of this disclosure, as shown herein with reference to Figures 1 to 1230. Figure 12 The embodiments discussed herein may be implemented by computer software executable by processor 1210 of device 1200, or by hardware, or by a combination of software and hardware. Processor 1210 may be configured to implement various embodiments of this disclosure. Moreover, the combination of processor 1210 and memory 1220 may form processing unit 1250 suitable for implementing various embodiments of this disclosure.

[0214] Memory 1220 can be of any type suitable for a local technology network and can be implemented using any suitable data storage technology, such as, as non-limiting examples, non-transitory computer-readable storage media, semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. Although only one memory 1220 is shown in device 1200, several physically different memory modules may exist in device 1200. Processor 1210 can be of any type suitable for a local technology network and may include one or more of the following: as non-limiting examples, general-purpose computers, special-purpose computers, microprocessors, digital signal processors (DSPs), and processors based on multi-core processor architectures. Device 1200 may have multiple processors, such as application-specific integrated circuit chips, which are time-dependent on a clock that synchronizes the main processor.

[0215] According to embodiments of this disclosure, a terminal device including a circuit is provided. The circuit is configured to: receive from a network device serving a first cell of the terminal device a Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) cell handover command for a future handover to a second cell at a future time instance; and delay the execution of the cell handover to the second cell indicated by the LTM-based cell handover command, at least in part based on a delay duration. According to embodiments of this disclosure, the circuit can be configured to perform any of the methods implemented by the terminal device as discussed above.

[0216] According to embodiments of this disclosure, a network device including circuitry is provided. The circuitry is configured to: send configuration information to a terminal device serving a first cell provided by the network device, the configuration information indicating at least one of the following: a delay duration, wherein the terminal device delays performing a cell handover to the second cell for a period of time after receiving a Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) cell handover command from a second cell; a time window for enabling the delayed cell handover function; a first indication for enabling or disabling the delayed cell handover function; or a second indication for enabling or disabling mobility prediction functionality at the terminal device; and send the Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) cell handover command from the second cell to the terminal device. According to embodiments of this disclosure, the circuitry can be configured to perform any of the methods implemented by the network device as discussed above.

[0217] As used herein, the term "circuit" can refer to hardware circuitry and / or a combination of hardware and software circuitry. For example, a circuit can be a combination of analog and / or digital hardware circuitry with software / firmware. As another example, a circuit can be any part of a hardware processor with software, including digital signal processors, software, and memory, which work together to enable a device (such as a terminal device or network device) to perform various functions. In yet another example, a circuit can be hardware circuitry and / or a processor (such as a microprocessor or a portion thereof) that requires software / firmware to operate, but which may be absent when operation is not required. As used herein, the term "circuit" also encompasses a specific implementation of hardware circuitry or a processor alone, or a portion thereof, and its accompanying software and / or firmware.

[0218] According to embodiments of this disclosure, a terminal device is provided. The terminal device includes: components for receiving, from a network device serving a first cell, a Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) cell handover command for a future handover to a second cell at a future time instance; and components for delaying the execution of a cell handover to the second cell indicated by the LTM-based cell handover command, at least in part based on a delay duration. In some embodiments, the first device may include components for performing corresponding operations of method 1000. In some example embodiments, the first device may also include components for performing other operations of some example embodiments of method 1000. The components may be implemented in any suitable form. For example, the components may be implemented as circuitry or software modules.

[0219] According to embodiments of this disclosure, a network apparatus is provided. The network apparatus includes: components for: sending configuration information to a terminal device serving a first cell provided by the network apparatus, the configuration information indicating at least one of the following: a delay duration, wherein the terminal device delays performing a cell handover to the second cell for a period of time after receiving a Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) cell handover command from a second cell; a time window for enabling the delayed cell handover function; a first indication for enabling or disabling the delayed cell handover function; or a second indication for enabling or disabling mobility prediction functionality at the terminal device; and components for: sending the Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) cell handover command from the second cell to the terminal device. In some embodiments, the second apparatus may include components for performing corresponding operations of method 1100. In some example embodiments, the second apparatus may also include components for performing other operations of some example embodiments of method 1100. The components may be implemented in any suitable form. For example, the components may be implemented as circuits or software modules.

[0220] In summary, the implementation scheme disclosed herein provides the following aspects.

[0221] In one aspect, a terminal device is proposed, the terminal device comprising: a processor configured to cause the terminal device to: receive from a network device serving a first cell of the terminal device a Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) cell handover command to a second cell to be handed over at a future time instance; and to delay the execution of the cell handover to the second cell indicated by the LTM-based cell handover command, at least in part based on a delay duration.

[0222] In some implementations, the processor is further configured to cause the terminal device to: receive configuration information from a first cell indicating at least one of the following: a delay duration; a time window for enabling delayed cell handover; a first indication for enabling or disabling delayed cell handover; a second indication for enabling or disabling mobility prediction at the terminal device; or a measurement configuration indicating measurement resources to be used by the terminal device to measure at least one of the following: the first cell or the second cell.

[0223] In some implementations, the configuration information is included in the LTM-based cell handover command, or in at least one first message that is different from the LTM-based cell handover command.

[0224] In some implementations, the configuration information is included in one of the following: Radio Resource Control (RRC) signaling, Media Access Control (MAC) control element (CE), or Downlink Control Information (DCI).

[0225] In some implementations, the DCI is carried on a physical downlink control channel (PDCCH) scrambled with a specific radio network temporary identifier (RNTI) or having a specific format.

[0226] In some implementations, the configuration information includes a first field for indicating a first indication and a second field for indicating a delay duration, and wherein if the function of the first field indicating a delay in performing cell handover is disabled, the processor is further configured to cause the terminal device to: ignore the second field, assume that at least a portion of the bits corresponding to the second field are set to reserved bits, assume that at least a portion of the bits corresponding to the second field are "0", or assume that the value of the delay duration indicated by the second field is zero.

[0227] In some implementations, the delay duration is represented by one of the following: the length of the delay duration, an index associated with the length of the delay duration, or a multiple of a predefined periodicity.

[0228] In some implementations, the latency duration is configured by the network device, defined as a default value, or determined based on machine learning (ML) related information.

[0229] In some implementations, the processor is further configured to cause the terminal device to: send feedback information of an LTM-based cell handover command to the network device at a second time instance, and perform a cell handover to the second cell at a third time instance, which is a first time slot following a period starting from the second time instance, the period including at least the delay duration.

[0230] In some implementations, the processor is further configured to cause the terminal device to: upon receiving an LTM-based cell handover command or feedback information indicating that an LTM-based cell handover command has been sent, start a timer corresponding to the delay duration; and upon the expiration of the timer, perform a cell handover to a second cell.

[0231] In some implementations, the processor is further configured to cause the terminal device to perform measurements on at least one of the first cell or the second cell after receiving an LTM-based cell handover command.

[0232] In some implementations, the processor is further configured to cause the terminal device to send a measurement report to the network device, the measurement report including measurement results of at least one of the following: a first cell or a second cell.

[0233] In some implementations, the measurement reports are periodic, semi-permanent, or non-periodic.

[0234] In some implementations, the measurement report includes at least one of the following: layer 1 or layer 3 measurement results of a first cell; layer 1 or layer 3 measurement results of a second cell; or a third indication of the status of whether predefined conditions for triggering a measurement report are met.

[0235] In some implementations, the processor is further configured to cause the terminal device to: send measurement information to the network device regarding at least one of the following, based on the determination that a predefined condition is met: a fourth indication for stopping a cell handover to a second cell indicated by an LTM-based cell handover command, or for initiating a cell handover to a second cell; or a measurement report including an indication that the predefined condition is met; a Layer 1 or Layer 3 measurement result of the first cell; or a Layer 1 or Layer 3 measurement result of the second cell.

[0236] In some implementations, the processor is further configured such that the terminal device determines that a predefined condition is met when at least one of the following is detected: the measurement quality of the second cell is lower than or equal to a first threshold quality; the measurement quality of the second cell is higher than or equal to a second threshold quality; the difference between the measurement quality of the second cell and the measurement quality of the first cell is greater than or equal to a third threshold quality; the difference between the measurement quality of the second cell and the measurement quality of the first cell is less than or equal to a third threshold quality; the difference between the measurement quality of the second cell and the predicted quality of the second cell is greater than or equal to a third threshold quality; or the difference between the measurement quality of the second cell and the predicted quality of the second cell is less than or equal to a third threshold quality.

[0237] In some implementations, measurement information is indicated by the physical uplink control channel (PUCCH) associated with a dedicated scheduling request (SR).

[0238] In some implementations, the processor is further configured to cause the terminal device to send measurement information or a measurement report when it determines that the number of times a predefined condition is met is greater than or equal to a threshold number.

[0239] In some implementations, the processor is further configured to cause the terminal device to perform at least one of the following: determining first measurement resources for measuring a first cell, including RS resources associated with a TCI state applied to the first cell; or determining second measurement resources for measuring a second cell, including reference signal (RS) resources associated with a transmit configuration indicator (TCI) state indicated in an LTM-based cell handover command, wherein the TCI state will be applied to the second cell.

[0240] In some implementations, the processor is further configured to cause the terminal device to receive a measurement configuration from the network device before performing a measurement on at least one of the first cell or the second cell, wherein the measurement configuration indicates that the terminal device will use to measure measurement resources of at least one of the following: the first cell or the second cell, and wherein the measurement configuration is included in an LTM-based cell handover command or in at least one second message different from the LTM-based cell handover command.

[0241] In some implementations, the measurement configuration includes at least one of the following: a third field indicating a set of parameters for reporting measurement results; a fourth field indicating that the measurement results are sent to a first cell; or a fifth field indicating measurement resources that will be used by the terminal device to measure at least one of the first cell or the second cell.

[0242] In some implementations, the processor is further configured to cause the terminal device to: during the delay duration, receive a third message indicating at least one of the following: a fifth indication for stopping the cell handover to the second cell indicated by the LTM-based cell handover command, or a sixth indication for starting the cell handover to the second cell.

[0243] In some implementations, the processor is further configured to cause the terminal device to perform a measurement on at least one of the first cell or the second cell during the initial period of the delay duration.

[0244] In some implementation schemes, the first cell is the serving cell, and the second cell is the target cell.

[0245] In one aspect, a network device is provided, the network device comprising: a processor configured to cause the network device to: send configuration information to a terminal device serving a first cell provided by the network device, the configuration information indicating at least one of the following: a delay duration, wherein the terminal device delays performing a cell handover to the second cell for a period of time after receiving a Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) cell handover command of a second cell; a time window for enabling the function of delaying the cell handover; a first indication for enabling or disabling the function of delaying the cell handover; or a second indication for enabling or disabling mobility prediction function at the terminal device; and send the Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) cell handover command of the second cell to the terminal device.

[0246] In some implementations, the configuration information is included in the LTM-based cell handover command, or in at least one first message that is different from the LTM-based cell handover command.

[0247] In some implementations, the configuration information is included in one of the following: Radio Resource Control (RRC) signaling, Media Access Control (MAC) control element (CE), or Downlink Control Information (DCI).

[0248] In some implementations, the DCI is carried on a physical downlink control channel (PDCCH) scrambled with a specific radio network temporary identifier (RNTI) or having a specific format.

[0249] In some implementations, the configuration information includes a first field for indicating a first indication and a second field for indicating the duration of a delay, and wherein if the function of the first field indicating a delay in performing cell handover is disabled, the processor is further configured to cause the network device to: ignore the second field, reuse at least a portion of the bits corresponding to the second field as reserved bits, set at least a portion of the bits corresponding to the second field to "0", or set the value of the delay duration indicated by the second field to zero.

[0250] In some implementations, the delay duration is represented by one of the following: the length of the delay duration, an index associated with the length of the delay duration, or a multiple of a predefined periodicity.

[0251] In some implementations, the latency duration is configured by the network device, defined as a default value, or determined based on machine learning (ML) related information.

[0252] In some implementations, the processor is further configured to cause the network device to receive a measurement report from the terminal device during the latency duration, the measurement report including measurement results of at least one of the following: a first cell or a second cell.

[0253] In some implementations, measurement reports are periodic, semi-persistent, non-periodic, or event-triggered.

[0254] In some implementations, the measurement report includes at least one of the following: layer 1 or layer 3 measurement results of a first cell; layer 1 or layer 3 measurement results of a second cell; or a third indication of the status of whether predefined conditions for triggering a measurement report are met.

[0255] In some implementations, the processor is further configured to cause the network device to: during the delay duration, receive trigger-based measurement information from the terminal device regarding at least one of the following: a fourth indication for stopping a cell handover to a second cell indicated by an LTM-based cell handover command, or for initiating a cell handover to a second cell; or a measurement report including an indication that predefined conditions are met; a Layer 1 or Layer 3 measurement result of the first cell; or a Layer 1 or Layer 3 measurement result of the second cell.

[0256] In some implementations, the trigger-based measurement information is indicated by the Physical Uplink Control Channel (PUCCH) associated with the Dedicated Scheduling Request (SR).

[0257] In some implementations, the processor is further configured to cause the network device to send measurement configurations associated with at least one of the first cell or the second cell to the terminal device.

[0258] In some implementations, the measurement configuration indication will be used by the terminal device to measure at least one of the following measurement resources: a first cell or a second cell, and wherein the measurement configuration is included in: an LTM-based cell handover command, configuration information, or at least one second message different from an LTM-based cell handover command.

[0259] In some implementations, the LTM-based cell handover command includes at least one of the following: a third field indicating a set of parameters for reporting measurement results; a fourth field indicating that the measurement results are sent to a first cell; or a fifth field indicating that the terminal device will use the measurement resources of at least one of the first cell or the second cell.

[0260] In some implementations, the processor is further configured to cause the terminal device to: during the delay duration, send a third message indicating at least one of the following: a fifth indication for terminating the delayed cell handover to the second cell, or a sixth indication for initiating the cell handover to the second cell.

[0261] In some implementation schemes, the first cell is the serving cell, and the second cell is the target cell.

[0262] In one aspect, a terminal device includes: at least one processor; and at least one memory coupled to the at least one processor and storing instructions that, when executed by the at least one processor, cause the device to perform the methods implemented by the terminal device as discussed above.

[0263] In one aspect, a network device includes: at least one processor; and at least one memory coupled to the at least one processor and storing instructions that, when executed by the at least one processor, cause the device to perform the methods implemented by the network device as discussed above.

[0264] In one aspect, a computer-readable medium storing instructions that, when executed on at least one processor, cause the at least one processor to perform the methods implemented by the terminal device discussed above.

[0265] In one aspect, a computer-readable medium stores instructions that, when executed on at least one processor, cause the at least one processor to perform the methods implemented by the network device discussed above.

[0266] In one aspect, a computer program includes instructions that, when executed on at least one processor, cause the at least one processor to perform the methods discussed above and implemented by the terminal device.

[0267] In one aspect, a computer program includes instructions that, when executed on at least one processor, cause the at least one processor to perform the methods implemented by the network device discussed above.

[0268] Generally, various embodiments of this disclosure can be implemented in hardware or special-purpose circuitry, software, logic, or any combination thereof. Some aspects can be implemented in hardware, while others can be implemented in firmware or software executable by a controller, microprocessor, or other computing device. Although various aspects of embodiments of this disclosure are illustrated and described using block diagrams, flowcharts, or other illustrations, it should be understood that, as non-limiting examples, the blocks, apparatuses, systems, techniques, or methods described herein can be implemented in hardware, software, firmware, special-purpose circuitry or logic, general-purpose hardware or controllers or other computing devices, or any combination thereof.

[0269] This disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer-executable instructions (such as those included in program modules) that execute on a target real or virtual processor in a device to perform the functions described above with reference to Figures 1 to 1. Figure 12 The described process or method. Generally, a program module includes routines, programs, libraries, objects, classes, components, data structures, etc., that perform specific tasks or implement specific abstract data types. The functionality of a program module can be combined in various implementation schemes or split among program modules as needed. The machine-executable instructions used for a program module can be executed on a local or distributed device. In a distributed device, a program module can reside on both local and remote storage media.

[0270] Program code used to perform the methods of this disclosure may be written in any combination of one or more programming languages. This program code may be provided to a processor or controller of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, such that, when executed by the processor or controller, the program code causes the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a stand-alone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0271] The aforementioned program code may be embodied on a machine-readable medium, which may be any tangible medium containing or storing a program used by or in connection with an instruction execution system, apparatus, or device. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. Machine-readable media may include, but are not limited to, electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatus, or devices, or any suitable combination thereof. More specific examples of machine-readable storage media will include electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable compact disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0272] Furthermore, although the operations are described in a specific order, this should not be construed as requiring such operations to be performed in the specific order shown or in sequential order, or to perform all the illustrated operations to achieve the desired result. In some environments, multitasking and parallel processing can be advantageous. While several specific implementation details are included in the foregoing discussion, these details should not be construed as limiting the scope of this disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features described in the context of individual embodiments may also be implemented in a single embodiment in combination. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0273] Although this disclosure has been described using language specific to structural features and / or methodological actions, it should be understood that the disclosure as defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are disclosed as examples of implementing the claims.

Claims

1. A terminal device, the terminal device comprising: a processor configured to cause the terminal device to: receive, from a network device providing a first cell serving the terminal device, a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM) based cell handover command of a second cell to be handed over to at a future time instance; and delay performing a cell handover to the second cell indicated by the LTM based cell handover command based at least in part on a delay duration. 2.The terminal device of claim 1, wherein the processor is further configured to cause the terminal device to: receive, from the first cell, configuration information indicating at least one of: the delay duration; a time window of a function of delaying performing cell handover being enabled; a first indication for enabling or disabling the function of delaying performing cell handover; a second indication for enabling or disabling a mobility prediction function at the terminal device; or a measurement configuration indicating measurement resources to be used by the terminal device for measuring at least one of: the first cell or the second cell. 3.The terminal device of claim 2, wherein the configuration information is included in the LTM based cell handover command or in at least one first message different from the LTM based cell handover command. 4.The terminal device of claim 2, wherein the configuration information is included in one of: radio resource control (RRC) signaling, medium access control (MAC) control element (CE) or downlink control information (DCI). 5.The terminal device of claim 4, wherein the DCI is carried on a physical downlink control channel (PDCCH) scrambled by a specific radio network temporary identifier (RNTI) or having a specific format. 6.The terminal device of claim 2, wherein the configuration information comprises a first field for indicating the first indication and a second field for indicating the delay duration, and wherein if the first field indicates that the function of delaying performing cell handover is disabled, the processor is further configured to cause the terminal device to: ignore the second field, assume that at least a part of bits corresponding to the second field are set as reserved bits, assume that at least a part of bits corresponding to the second field are "0", or Assuming a value of the delay duration indicated by the second field is zero.

7. The terminal device of claim 1, wherein the delay duration is represented by one of: a time length of the delay duration, an index associated with the time length of the delay duration, or a multiple of a predefined periodicity.

8. The terminal device of claim 1, wherein the delay duration is configured by the network device, defined as a default value, or determined based on machine learning (ML) related information.

9. The terminal device of claim 1, wherein the processor is further configured to cause the terminal device to: send, to the network device, feedback information of the LTM-based cell handover command at a second time instance; and perform the cell handover to the second cell at a third time instance, the third time instance being a first time slot after a time period from the second time instance, the time period comprising at least the delay duration.

10. The terminal device of claim 1, wherein the processor is further configured to cause the terminal device to: start a timer corresponding to the delay duration after receiving the LTM-based cell handover command or sending feedback information of the LTM-based cell handover command; and perform the cell handover to the second cell upon expiration of the timer.

11. The terminal device of claim 1, wherein the processor is further configured to cause the terminal device to: perform a measurement on at least one of the first cell or the second cell after receiving the LTM-based cell handover command.

12. The terminal device of claim 11, wherein the processor is further configured to cause the terminal device to: send, to the network device, a measurement report comprising a measurement result of at least one of: the first cell or the second cell.

13. The terminal device of claim 12, wherein the measurement report is a periodic, semi-persistent, or aperiodic measurement report.

14. The terminal device of claim 12, wherein the measurement report comprises at least one of: a layer 1 or layer 3 measurement result of the first cell; a layer 1 or layer 3 measurement result of the second cell; or a third indication indicating a status on whether a predefined condition triggering the measurement report is satisfied.

15. The terminal device of claim 11, wherein the processor is further configured to cause the terminal device to: in accordance with a determination that a predefined condition is satisfied, send, to the network device, measurement information on at least one of: a fourth indication to stop the cell handover to the second cell indicated by the LTM-based cell handover command, or to start the cell handover to the second cell; or a measurement report comprising an indication indicating that the predefined condition is satisfied. a Layer 1 or Layer 3 measurement result of the first cell; or a Layer 1 or Layer 3 measurement result of the second cell.

16. The terminal device of claim 14 or 15, wherein the processor is further configured to cause the terminal device to: determine that the predefined condition is satisfied upon detecting at least one of: a measurement quality of the second cell being lower than or equal to a first threshold quality, the measurement quality of the second cell being higher than or equal to a second threshold quality, a difference between the measurement quality of the second cell and a measurement quality of the first cell being greater than or equal to a third threshold quality, the difference between the measurement quality of the second cell and the measurement quality of the first cell being less than or equal to a third threshold quality; a difference between the measurement quality of the second cell and a predicted quality of the second cell being greater than or equal to a third threshold quality, or the difference between the measurement quality of the second cell and the predicted quality of the second cell being less than or equal to a third threshold quality.

17. The terminal device of claim 15, wherein the measurement information is indicated by a physical uplink control channel (PUCCH) associated with a dedicated scheduling request (SR).

18. The terminal device of claim 14 or 15, wherein the processor is further configured to cause the terminal device to: transmit the measurement information or the measurement report upon determining that a number of times that the predefined condition is satisfied is greater than or equal to a threshold number of times.

19. The terminal device of claim 11, wherein the processor is further configured to cause the terminal device to perform at least one of: determine a first measurement resource for measuring the first cell, the measurement resource comprising a RS resource associated with a TCI state applied to the first cell; or determine a second measurement resource for measuring the second cell, the measurement resource comprising a RS resource associated with a TCI state indicated in the LTM-based cell handover command, wherein the TCI state is to be applied to the second cell.

20. The terminal device of claim 11, wherein the processor is further configured to cause the terminal device to: receive a measurement configuration from the network device prior to performing the measurement on at least one of the first cell or the second cell, wherein the measurement configuration indicates a measurement resource to be used by the terminal device for measuring at least one of: the first cell or the second cell, and wherein the measurement configuration is comprised in the LTM-based cell handover command or in at least one second message different from the LTM-based cell handover command.

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