Transmission configuration indicator (TCI) activation

Abstract

A method includes receiving, by a user equipment (UE) connected to a first cell, an activation for a first configured transmission configuration indicator (TCI) state in a first pool of TCI states associated with a second cell and further receiving a configuration for a second TCI state in a second pool of TCI states associated with the second cell. The UE determines that a first activated TCI state and the second TCI state share one or more properties, and activates the second TCI state of the second cell based on the determination. And the UE performs cell handover to the second cell, thereby maintaining the activated second TCI state of the second cell.

Description

Technical Field

[0001] The various example implementations generally relate to wireless networking, and more specifically to the Transmission Configuration Indicator (TCI) status for mobility in wireless networking. Background Technology

[0002] Wireless networking offers significant advantages to user mobility. The ability to maintain connectivity while on the move not only benefits users but also contributes to greater efficiency and productivity for society as a whole. As user expectations for connection reliability, data speed, and device battery life increase, the technologies used for wireless networking must keep pace with these expectations. Therefore, there has been ongoing interest in improving wireless networking technologies. To this end, cellular standards have developed cell handover at various protocol layers: conventional Layer 3 handover has existed for several generations. In addition, conditional handover has been introduced to improve handover reliability. Recent developments envision a lower-layer handover known as Layer 1 / Layer 2 triggered mobility (LTM). Therefore, efforts to reduce latency during handover may be valuable. Summary of the Invention

[0003] In one aspect of this disclosure, a method includes: a user equipment (UE) connected to a first cell receiving activation of a first TCI state in a first configured Transport Configuration Indicator (TCI) state pool associated with a second cell, and further receiving configuration of a second TCI state in a second TCI state pool associated with the second cell. The UE determines that the first activated TCI state and the second TCI state share one or more properties, and activates the second TCI state of the second cell based on the determination. The UE performs a cell handover to the second cell, thereby maintaining the activated second TCI state of the second cell.

[0004] In one aspect of the method, the UE maintains the activated second TCI state of the second cell when switching to the second cell.

[0005] In one aspect of the method, the activation of the second TCI state of the second cell is determined after handover to the second cell.

[0006] In one aspect of the method, the activation of the second TCI state of the second cell is determined after receiving a cell handover command to switch the UE to the second cell.

[0007] In one aspect of the method, the activation of the second TCI state of the second cell is determined after receiving and confirming the cell handover command to switch the UE to the second cell.

[0008] In one aspect of the method, the activation of the second TCI state of the second cell is determined after processing the cell handover command to switch the UE to the second cell.

[0009] In one aspect of the method, the first activated TCI state in the first TCI state pool is associated with a beam management configuration for the second cell, and the second TCI state in the second TCI state pool is associated with a lower-layer triggered mobility (LTM) configuration for the second cell.

[0010] In one aspect of the method, the first activated TCI state in the first TCI state pool is associated with a lower-layer triggered mobility (LTM) configuration for the second cell, and the second TCI state in the second TCI state pool is associated with a beam management configuration for the second cell.

[0011] In one aspect of the method, the second cell is configured as an LTM candidate cell.

[0012] In one aspect of the method, the second cell is configured as the serving cell.

[0013] In one aspect of the method, the determination that the first activated TCI state and the second TCI share one or more properties includes determining that the quasi-co-address (QCL) reference signal of the first activated TCI state is equivalent to the QCL reference signal of the second TCI state.

[0014] In one aspect of the method, the determination that the first activated TCI state and the second TCI share one or more properties includes determining that the quasi-co-address (QCL) reference signal of the first activated TCI state shares one or more properties with the QCL reference signal of the second TCI state.

[0015] In one aspect of the method, one or more QCL properties include one or more of the following: Doppler spread, Doppler frequency shift, delay spread, or average delay.

[0016] In one aspect of the method, the QCL reference signal of the first activated TCI state and the QCL reference signal of the second TCI state share one or more properties, including that the QCL reference signal of the first activated TCI state includes the same QCL source reference signal (RS).

[0017] In one aspect of the method, the activation of the first TCI state in the first TCI state pool associated with the second cell and the second TCI state in the second TCI state pool associated with the second cell is included in the Media Access Control (MAC) Control Element (CE) message.

[0018] In one aspect of this disclosure, a user equipment (UE) includes: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the device to perform at least one of the foregoing methods.

[0019] In one aspect of this disclosure, a processor-readable medium storage instruction is provided, which, when executed by at least one processor of a device, causes the device to perform at least any of the aforementioned methods.

[0020] In one aspect of this disclosure, a method includes a first cell sending a first message to a user equipment (UE) based on one or more properties shared by a first activated TCI state in a first Transport Configuration Indicator (TCI) state pool associated with a second cell and a second TCI state in a second TCI state pool associated with the second cell. The first message includes at least the first activated TCI state and the second TCI state. The first cell uses the first TCI state for beam management and sends an instruction to the UE for a mobility (LTM) cell handover triggered at a lower layer of the second cell, the instruction including the second TCI state of the second cell.

[0021] In one aspect of this disclosure, the instructions for the LTM cell handover include a command for handover to the LTM cell of the second cell.

[0022] In one aspect of the method, determining that the first activated TCI state and the second TCI state share one or more properties includes determining that the quasi-co-address (QCL) reference signal of the first activated TCI state is equivalent to the QCL reference signal of the second TCI state.

[0023] In one aspect of the method, determining that the first activated TCI state and the second TCI share one or more properties includes determining that the quasi-co-address (QCL) reference signal of the first activated TCI state shares one or more properties with the QCL reference signal of the second TCI state.

[0024] In one aspect of the method, one or more QCL properties include one or more of the following: Doppler spread, Doppler frequency shift, delay spread, or average delay.

[0025] In one aspect of the method, the QCL reference signal of the first activated TCI state and the QCL reference signal of the second TCI state share one or more properties, including that the QCL reference signal of the first activated TCI state includes the same QCL source reference signal (RS).

[0026] In one aspect of the method, the first activated TCI state in the first TCI state pool is associated with a lower-layer triggered mobility (LTM) configuration for the second cell, and the second TCI state in the second TCI state pool is associated with a beam management configuration for the second cell.

[0027] In one aspect of the method, the second cell is configured as an LTM candidate cell.

[0028] In one aspect of the method, the second cell is configured as the serving cell.

[0029] In one aspect of the method, the first message is a Media Access Control (MAC) Control Element (CE) message.

[0030] In one aspect of the method, an apparatus includes: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to perform at least one of the foregoing methods.

[0031] In one aspect of this disclosure, a processor-readable medium storage instruction is provided, which, when executed by at least one processor of a device, causes the device to perform at least any of the aforementioned methods.

[0032] The independent claims provide the subject matter according to several aspects. Additional aspects are defined in the dependent claims. Attached Figure Description

[0033] Some example implementation schemes will now be described with reference to the accompanying drawings.

[0034] Figure 1 This is a diagram of an example embodiment of a wireless networking between a network system and a user equipment (UE) according to one aspect of this disclosure; Figure 2 This is a diagram of an example embodiment of a transmit and receive beam for wireless networking between a network device and a user equipment (UE) according to one aspect of this disclosure; Figure 3 This is a diagram of an example embodiment of a UE sweeping a receive beam for a synchronization signal block (SSB) burst, according to one aspect of this disclosure; Figure 4 This is a diagram of an example implementation of a layer 1 / layer 2 triggered mobility (LTM) scenario according to one aspect of this disclosure; Figure 5 This is a diagram of an example implementation of a contention-based random access procedure according to one aspect of this disclosure; Figure 6 This is a diagram of an example embodiment of signaling and operation between the UE, Central Unit (CU), Source Distributed Unit (DU), and Target DU in relation to an aspect of this disclosure; Figure 7 This is a graph showing the example transport configuration (TCI) state switching delay used for adding TCI states to the active TCI state list; Figure 8 This is a diagram illustrating an example embodiment of signaling and operation between the UE, CU, source cell, and candidate cell during the LTM TCI activation process, according to one aspect of this disclosure; and Figure 9 This is a diagram of an example implementation of a component of a UE or network device according to one aspect of this disclosure. Detailed Implementation

[0035] In the following description, certain specific details are set forth in order to provide a thorough understanding of the disclosed aspects. However, those skilled in the art will recognize that the aspects can be practiced without one or more of these specific details or using other methods, components, materials, etc. In other instances, well-known structures associated with transmitters, receivers, or transceivers have not been shown or described in detail so as not to unnecessarily obscure the description of the aspects.

[0036] Throughout this specification, the reference to "an aspect" or "one aspect" means that a particular feature, structure, or characteristic described in connection with said aspect is included in at least one aspect. Therefore, the appearance of the phrase "in an aspect" or "in one aspect" in various places throughout this specification does not necessarily refer to the same aspect. Furthermore, in one or more aspects, a particular feature, structure, or characteristic may be combined in any suitable manner.

[0037] The implementations described in this disclosure can be implemented in wireless networking devices, such as, but not limited to, devices utilizing Global Microwave Access Interoperability (WiMAX), Global System for Mobile Communications (GSM, 2G), GSM EDGE Radio Access Network (GERAN), General Packet Radio Service (GPRS), Universal Mobile Telecommunications System based on Basic Wideband Code Division Multiple Access (W-CDMA) (UMTS, 3G), High-Speed ​​Packet Access (HSPA), Long Term Evolution (LTE), LTE-Advanced, Enhanced LTE (eLTE), 5G New Radio (5G NR), 5G Advance, 6G (and beyond), and 802.11ax (Wi-Fi 6), and other wireless networking systems. The term 'eLTE' here refers to LTE evolution connected to a 5G core. LTE is also referred to as Evolved UMTS Terrestrial Radio Access (EUTRA) or Evolved UMTS Terrestrial Radio Access Network (EUTRAN).

[0038] Since a UE can move from one area to another, handover or mobility procedures can be important to support continuous communication between the UE and the network (without any or at least minimal interruption). In an example, the UE can be configured to monitor certain reference signals (e.g., SSB, Channel State Information Reference Signal (CSI-RS), DL Reference Signal (RS)) from one or more network devices, perform signal measurements of these reference signals, and report those measurements to the network, enabling a determination to hand over the UE to a neighboring cell (e.g., upon detection of signal quality degradation). Handover initiation can typically be initiated from the network. In 5G NR examples, handover initiation or handover commands can be signaled via higher-layer signaling (e.g., Layer 3 or Radio Resource Control (RRC) signaling). Higher-layer signaling can involve the network and therefore may have high latency. In various situations, the UE can benefit from a more efficient handover process triggered via lower-layer signaling (e.g., L1 / L2 signaling), which has lower latency compared to higher-layer signaling. As used herein, a handover triggered via lower-layer signaling can be referred to as lower-layer triggered mobility (LTM). In some instances, candidate cells used for LTM can be referred to as LTM candidate cells.

[0039] As used herein, the term "cell handover" means and refers to any change of a cell, whether the change is triggered via Layer 1 signaling, Layer 2 signaling, and / or Layer 3 signaling, or other signaling. A cell handover can be performed on a terminal device in RRC connected mode, and therefore may involve bidirectional signaling between the terminal device and at least one network node of the radio access network (typically at least the source network node and the destination network node of the cell handover). This disclosure primarily uses LTM as an example of cell handover, but it is intended and should be understood that this disclosure can operate with Layer 3 handover or any cell handover.

[0040] This disclosure may use the term "serving cell" to refer to a network node or network device (or a portion thereof) serving a UE, the term "candidate cell" to refer to a network node or network device (or a portion thereof) that is a potential target of a cell handover command, and the term "target cell" to refer to a network node or network device (or a portion thereof) that is the target of a cell handover command. In some examples, the LTM target may also be the serving cell (e.g., the target may be "SCell," i.e., a secondary cell in carrier aggregation).

[0041] As used herein, the terms “send toward,” “receive from,” and “cooperate with” (and variations thereof) include communication that may or may not involve communication through one or more intermediate devices or nodes. The term “acquire” (and variations thereof) includes acquiring in a first instance or acquiring again after a first instance. The term “connection” can mean a physical connection or a logical connection.

[0042] Figure 1 This is a diagram illustrating an example of wireless networking between network system 100 and user equipment (UE) 150. Network system 100 may include one or more network nodes 120, one or more servers 110, and / or one or more network devices 130 (e.g., test equipment). Network node 120 will be described in more detail below. As used herein, the term "network device" may refer to any component of network system 100, such as server 110, network node 120, network device 130, any component of the foregoing, and / or any other component of network system 100. Examples of network devices include, but are not limited to, devices implementing various aspects of 5G NR, etc. This disclosure describes implementations related to 5G NR and implementations involving aspects defined by the 3rd Generation Partnership Project (3GPP). However, it is contemplated that implementations related to other wireless networking technologies are covered within the scope of this disclosure.

[0043] The following describes additional details of examples of network nodes. In a 5G NR network, a gNodeB (also known as a gNB) may include, for example, a node that provides NR user plane and control plane protocol terminals to the UE and is connected to the 5G core (5GC) via an NG interface, as per Section 3.2 of 3GPP TS 38.300 V16.6.0 (2021-06), which is incorporated herein by reference.

[0044] gNB supports various protocol layers, such as Layer 1 (L1) (i.e., the physical layer), Layer 2 (L2), and Layer 3 (L3).

[0045] NR's Layer 2 (L2) is broken down into the following sublayers: Media Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), and Service Data Adaptation Protocol (SDAP), among which, for example: ○ The physical layer provides a transmission channel to the MAC sublayer; ○ The MAC sublayer provides logical channels to the RLC sublayer; ○ The RLC sublayer provides RLC channels to the PDCP sublayer; ○ The PDCP sublayer provides radio bearers to the SDAP sublayer; ○ The SDAP sublayer provides Quality of Service (QoS) flows to 5GC; ○ The control channels include the Broadcast Control Channel (BCCH) and the Physical Control Channel (PCCH).

[0046] Layer 3 (L3) includes, for example, Radio Resource Control (RRC), as per Section 6 of 3GPP TS 38.300 V16.6.0 (2021-06), which is incorporated herein by reference.

[0047] The gNB Central Unit (gNB-CU) includes, for example, logical nodes that host, the radio resource control (RRC), service data adaptation protocol (SDAP), and packet data convergence protocol (PDCP) protocols of the gNB, or the RRC and PDCP protocols of the en-gNB. These logical nodes control the operation of one or more gNB Distributed Units (gNB-DUs). The gNB-CU terminates the F1 interface connected to the gNB-DU. The gNB-CU may also be referred to herein as a CU, central unit, centralized unit, or control unit.

[0048] A gNB Distributed Unit (gNB-DU) comprises, for example, a logical node that hosts the Radio Link Control (RLC), Media Access Control (MAC), and Physical (PHY) layers of a gNB or en-gNB, and the operation of said logical node is partially controlled by the gNB-CU. One gNB-DU supports one or more cells. A cell is supported by only one gNB-DU. The gNB-DU terminates the F1 interface connected to the gNB-CU. The gNB-DU may also be referred to herein as a DU or Distributed Unit.

[0049] As used herein, the term "network node" may refer to any one or any combination of gNB, gNB-CU, or gNB-DU. RAN (Radio Access Network) nodes or network nodes (such as, for example, gNB, gNB-CU, or gNB-DU, or portions thereof) may be implemented using, for example, a device having at least one processor and / or at least one memory having processor-readable instructions ("programs") configured to support and / or configure and / or process CU and / or DU-related functionalities and / or features and / or at least one protocol (sub) layer (e.g., layer 2 and / or layer 3) of the RAN (Radio Access Network). Different functional splits between central and distributed units are possible. Examples of such devices and components will be described below in conjunction with Figure 12.

[0050] The gNB-CU and gNB-DU portions can be, for example, co-located or physically separate. The gNB-DU can even be further split, for example, into two parts, one including processing equipment and the other including an antenna. The Central Unit (CU) can also be referred to as BBU / REC / RCC / C-RAN / V-RAN, O-RAN, or a portion thereof. The Distributed Unit (DU) can also be referred to as RRH / RRU / RE / RU, or a portion thereof. In the various example embodiments of this disclosure, a network node supporting at least one of the Central Unit functionality or Layer 3 protocols of a radio access network can be, for example, a gNB-CU. Similarly, a network node supporting at least one of the Distributed Unit functionality or Layer 2 protocols of a radio access network can be, for example, a gNB-DU.

[0051] A gNB-CU can support one or more gNB-DUs. A gNB-DU can support one or more cells, and therefore can support serving cells for User Equipment (UE) or candidate cells for handover, dual connectivity and / or carrier aggregation and other procedures.

[0052] User equipment (UE) 150 may be or include wireless or mobile devices, devices having a radio interface for interacting with a RAN (Radio Access Network), smartphones, in-vehicle devices, IoT devices, or M2M devices, and other types of user equipment. Such a UE 150 may include: at least one processor; and at least one memory including program code; wherein the at least one memory and the computer program code are configured, together with the at least one processor, to cause the device to perform at least some operations, such as, for example, an RRC connection to the RAN. An example of the components of the UE will be described in conjunction with Figure 12. In an embodiment, the UE 150 may be configured to generate messages (e.g., including a cell ID) to be transmitted via radio toward the RAN (e.g., to reach and communicate with the serving cell). In an embodiment, the UE 150 may generate, transmit, and receive RRC messages containing one or more RRC PDUs (Packet Data Units). Those skilled in the art will understand the RRC protocol and other processes that the UE may perform.

[0053] Continue to refer to Figure 1 In an example of a 5G NR network, network system 100 provides one or more cells that define the coverage area of ​​network system 100. As described above, network system 100 may include a gNB of the 5G NR network, or may include any other device configured to control radio communications and manage radio resources within the cell. As used herein, the term "resource" may refer to radio resources such as resource blocks (RBs), physical resource blocks (PRBs), radio frames, subframes, time slots, subbands, frequency regions, subcarriers, beams, etc. In an implementation, network node 120 may be referred to as a base station.

[0054] Figure 1 Examples are provided, and are merely illustrative of network system 100 and UE 150. Those skilled in the art will understand that network system 100 includes... Figure 1 Components not shown in the diagram, and it will be understood that other user equipment devices may communicate with network system 100.

[0055] Figure 2This is a diagram of an example embodiment of wireless networking between network device 210 and user equipment (UE) 150. Network device 210 is configured to form beams 220 in multiple directions, and UE 150 is also configured to form beams 260 in multiple directions. As those skilled in the art will understand, the ability to perform beamforming in multiple directions can be achieved using an arrangement of multiple radiating elements, which may also be referred to as an “array” of radiating elements. Beamforming (also known as spatial filtering) achieves directional signal transmission or reception by utilizing individual arrays and / or by combining elements in an array in a manner that causes signals at specific angles to produce constructive or destructive interference. Beamforming for transmission is achieved by controlling the phase and relative amplitude of the transmitted signal at each radiating element in the array to form a desired pattern of constructive and destructive interference in a desired wavefront. In contrast, beamforming for reception is achieved by combining information from different elements of the array in a manner that preferentially observes radiation in a target spatial region.

[0056] In the example shown, network device 210 (e.g., gNodeB or a portion thereof) and UE 150 may each be equipped with one or more antenna panels or antenna arrays having antenna elements that can be configured to beamform in certain spatial directions and / or certain spatial angular sectors or widths.

[0057] Continue to refer to Figure 1 Various examples of beam 220 are shown for network device 210, and various examples of beam 260 are shown for UE 150. As a result of using highly directional beams, some of the network device beams 120 may not be usable with some of the UE beams 160 due to significant directional differences. Therefore, in the implementation, UE 150 “sweeps” its beam 260, and network device 210 “sweeps” its beam 220 to determine which beam pair has the highest signal power and is therefore best suited for communication. Due to various propagation conditions, beams that are not perfectly aligned in direction may have the highest signal power. This will be combined with... Figure 3 A more detailed description of sweeping is provided. After identifying this beam pairing, UE 150 and network device 210 can use the identified beam to initiate an access procedure for UE 150 to access network device 210.

[0058] Figure 3 This is a diagram of an example implementation scheme for a UE to sweep the receive beam for an SSB burst. Using... Figure 2The example beams shown are formed sequentially by network device 210, consisting of beams B1, B2, B3, and B4. Each beam formation is referred to as a "burst." Network device 210 can generate bursts at intervals for observation by UE 150. Each time interval between these intervals is called a "burst period," which can be longer than the duration of the burst.

[0059] In 5G NR examples, each beam in a burst transmits information about the beam in a so-called Signal Synchronization Block (SSB). Network device 210, which may be a gNodeB or a portion thereof, transmits the SSB in each beam of the burst. In some examples, network device 210 may operate using one SSB (single-beam operation) or multiple SSBs (multi-beam operation). In the implementation, UE 150 may receive the SSB burst for each of its receive beams. Figure 2 In the example shown, with four receiving beams R1, R2, R3, and R4, receiving a burst of all four receiving beams requires four intervals, as... Figure 3 As shown. In some examples, the UE 150 can operate using a single beam (e.g., an omnidirectional beam). The SSB of an SS burst can be provided by one or more (co-located or non-co-located) TRPs (transmit-receive points). The duration between bursts is called "burst periodicity". In 5G NR networks, each SSB burst can last 5 ms, and burst periodicity can have a default duration of 20 ms.

[0060] In the 5G NR example, each SSB includes System Information (SI) in the form of a Main Information Block (MIB) and multiple System Information Blocks (SIBs). SIs are divided into Minimum SIs and other SIs. Minimum SIs include basic information that can be used to access network nodes and information for obtaining any other SIs. Minimum SIs include MIBs containing cell prohibition state information and physical layer information for receiving additional system information (e.g., CORESET#0 configuration). MIBs are periodically broadcast on the Broadcast Channel (BCH). Minimum SIs also include System Information Block 1 (SIB1), which defines the scheduling of other system information blocks and contains information for accessing network nodes. SIB1 can also be referred to as the Residual Minimum SI (RMSI) and is periodically broadcast on the Downlink Shared Channel (DL-SCH).

[0061] Also refer to Figure 2In an example such as 5G NR as defined by the 3rd Generation Partnership Project (3GPP), a Unified Transport Configuration Indicator (TCI) framework is used for beam configuration and / or indication. For example, network device 210 can configure a set of TCI states to UE 150. Each TCI state can indicate at least one beam direction or a set of beam directions that can correspond to a reference signal. In one example, a TCI state could be a DL TCI state for downlink (DL) communication from network device 210 to UE 150. In other examples, a TCI state could be a UL TCI state for uplink (UL) communication from UE 150 to network device 210. In yet another example, a TCI state could be a combined TCI state for UL and DL communication between network device 210 and UE 150. Network device 210 can utilize at least a subset of the configured TCI states to “activate” the UE. As used herein, “activating” a TCI state means that UE 150 can monitor signals, such as reference signals, transmitted by network device 210 corresponding to the TCI state. In examples, activation of a TCI state may mean that the UE is configured to monitor at least one reference signal associated with the activated TCI state, for example, for time / frequency tracking and / or path loss measurement. In examples, activation may mean that UE 150 intends to track at least one reference signal corresponding to the activated TCI state. In some examples, network device 210 may activate one or more of the configured TCI states in the set and exclude one or more other configured TCI states in the set. Additionally, in order to communicate with UE 150, network device 210 may select one of the activated TCI states and “indicate” the selected TCI state to UE 150. As used herein, “indicating” a TCI state means that UE 150 can be configured to communicate with network device 210 using a beam (identified by a downlink reference signal) corresponding to the indicated TCI state. In various examples, UE 150 may be prepared to receive an indication of at least one of the activated TCI states, and prepared to use the indicated TCI state to communicate with network device 210 within a specified time limit.

[0062] Figure 2 and Figure 3 The examples are merely illustrative. In implementations, the number and orientation of network node beams and the number and orientation of UE beams can vary and can be compared with... Figure 2 and Figure 3 The differences shown in the text.

[0063] As explained above, a UE can travel from one area to another, and therefore cell handover or mobility procedures (e.g., Layer 3 handover or LTM) can be important for supporting continuous communication between the UE and the network. Additionally, more efficient cell handover procedures (such as LTM) can help avoid or at least reduce UE service interruptions when the UE moves from one cell coverage area to another.

[0064] Figure 4 This is a diagram of an example implementation scheme for an LTM scenario. (See diagram for example.) Figure 4 As shown, UE 410 can communicate with and be served by network device 420 (e.g., gNB or a portion thereof), as indicated by the solid arrow. UE 410 can communicate with... Figure 1 The UE 150 is basically similar. Network device 420 can be used with... Figure 1 Network device 110 is essentially similar. Network device 420, which actively or currently serves UE 410, can be referred to as the serving cell. As UE 410 moves toward the edge of a cell or area 402 served (or under the coverage of) network device 420, a cell handover procedure can be performed to transfer UE 410 to a neighboring cell served, for example, by another network device 430, 440. Figure 4 In the illustrated example, one neighboring cell is served by network device 430, and another neighboring cell is served by network device 440. Network device 440 may cover (or serve) cell or area 406, while network device 430 may cover area 404. In some examples, areas 402, 404, and 406 may partially overlap, as shown in the figure. In other examples, areas 402, 404, and 406 may not overlap. In the context of handover, neighboring cells may be referred to as candidate cells. In the context of LTM, neighboring cells may be referred to as LTM candidate cells.

[0065] The term Layer 1 / Layer 2 triggered mobility (LTM) can also be referred to as L1 / L2 triggered mobility, L1 / L2 inter-cell mobility, L1 / L2 handover, or lower-layer (L1 / L2) mobility. These terms are used interchangeably. An L1 / L2 signal, message, or command sent by a network node to trigger a cell handover at the UE is called a “cell handover command.” In LTM, the decision regarding cell handover is based on L1 measurements and is performed at the MAC layer in the Distributed Cell (DU). The cell handover command includes a MAC Control Element (MAC CE). The cell targeted by the cell handover command may be referred to herein as the target cell. References will be made below. Figures 7 to 1 1. A more comprehensive discussion of the mechanisms used for LTM.

[0066] According to one aspect of this disclosure, network device 420 (serving cell) can activate TCI states for candidate cells for UE 410, and can optionally indicate activated TCI states that can be used by UE 410 in the event of a cell handover. In this regard, network device 420 can send an indication of one or more candidate cells (e.g., network devices 430 and 440) and activation of a corresponding list of one or more TCI states for each of the one or more candidate cells. Upon detecting a degradation in operation or communication with UE 410, serving cell network device 420 can send a cell handover command to UE 410 via lower-layer signaling (e.g., L1 / L2 signaling). The cell handover command can select one of the one or more candidate cells as the target cell for cell handover. In response to receiving the cell handover command, UE 410 can switch to communicating with the target cell by applying at least one of the corresponding one or more activated TCI states.

[0067] Figure 4 The examples are merely illustrative. In implementations, the number of candidate cells and the number of activated TCI states (or beams) can vary and can be compared with... Figure 4 The differences shown in the text.

[0068] The process used for a UE to establish communication with a target cell is called a random access procedure. Random access procedures can be used for initial access, small data transmission during inactivity, and transition from RRC_Inactive to RRC_Connected, as well as for beam fault recovery, connection reconstruction, handover, and cell addition, and other procedures that those skilled in the art will recognize.

[0069] The two types of random access procedures include contention-based random access (CBRA) and contention-free random access (CFRA). Figure 5 This is a diagram illustrating an example of a contention-based random access (CBRA) procedure. In the example shown, the signals include a random access preamble (MSG1) sent by UE 550 to network node 510 (e.g., gNodeB or a portion thereof), a random access response (MSG2) sent from network node 510 to UE 550, a scheduling transmission (MSG3) sent from UE 550 to network node 510, and a contention resolution (MSG4) sent from network node 510 to UE 550.

[0070] For MSG1, UE 550 is based on Signal Synchronization Block (SSB) (as described above). Figure 3The UE 550 uses information elements in the described SSB (Security Service Block) to select the available random access preamble. The UE 550 uses specific time and frequency resources called the Random Access Timing (RO) to send the random access preamble (MSG1) to the network node 510. The UE 550 also provides the network with an identifier called the Random Access Radio Network Temporary Identifier (RA-RNTI), enabling the network to address the UE in the next step.

[0071] For MSG2, network node 110 detects the preamble, calculates various quantities, and sends a Physical Uplink Shared Channel (PUSCH) Uplink (UL) grant to UE 550. This is called a Random Access Response (RAR), which is sent as MSG2 addressed to UE 550 using the associated RA-RNTI and indicates to UE 550 at which frequency and time it can send MSG3 on the PUSCH.

[0072] For MSG3, in response to receiving MSG2 from network node 510, UE 550 uses the UL authorization provided in the RAR to send MSG3. Since the RAR provides time resource allocation, UE 550 sends MSG3 to network node 510 at the timing specified by the time resource allocation, and it is a scheduled transmission. This MSG3 can be referred to as a Radio Resource Control (RRC) Connection Request message.

[0073] For MSG4, network node 510 can send MSG4 to UE 550 for contention resolution. Contention resolution can operate in a manner specified by 3GPP for 5G NR. After the random access procedure, assuming the contention resolution is successfully completed, UE 550 becomes connected to network node 510. After connection establishment, various procedures will be handled by gNB-CU according to CU-DU splitting. Those skilled in the art will understand other aspects of contention-based random access (CBRA).

[0074] Another type of random access procedure is Contention-Free Random Access (CFRA) (not shown). In CFRA (not shown), network node 510 sends an assigned random access preamble to UE 550. UE 550 receives the assigned random access preamble and sends it as MSG1 to network node 510 in its random access request. MSG2 and MSG3 are then similar to those described in conjunction with CBRA. Based on the use of the assigned random access preamble, conflict resolution is not required in CFRA. Other aspects of Contention-Free Random Access (CFRA) will be understood by those skilled in the art.

[0075] When a UE moves from the coverage area of ​​one cell to another, a serving cell change occurs at a certain point. A regular serving cell change can be triggered by Layer 3 (L3) measurements (from the UE's RRC measurement report) and accomplished via downlink RRC signaling (i.e., synchronized RRC reconfiguration messages for changes to the primary cell (PCell) and primary / secondary cell (PSCell), and, where applicable, for the release and addition of secondary cells (Scells). All cases involve a full L2 (and L1) reset, which can result in longer latency, greater overhead, and longer downtime compared to beam-switching mobility. By leveraging L1 / L2 mobility enhancements to enable serving cell changes via L1 / L2 signaling, latency, overhead, and downtime can be reduced.

[0076] Figure 6 This is a diagram of an example embodiment 600 of signals and operations related to LTM between the UE, Central Unit (CU), Source Distributed Unit (DU), and Target DU, based on one aspect of this disclosure. It is intended and should be understood that other types of cell handover procedures (e.g., Layer 3 handover) are within the scope of this disclosure. The following paragraphs will describe various signals and operations. It will be understood that the described signals may have associated operations, and the described operations may have associated signals.

[0077] Now for reference Figure 6 This illustrates example signals and operations related to LTM and random access procedures in conjunction with inter-DU cell handover. The inter-DU scenario is illustrative, and aspects of this disclosure can also be applied to intra-DU scenarios. Where the source DU and target DU are supported by different CUs, the source DU may be supported by the source CU, and the target DU may be supported by the target CU, which can communicate via an Xn interface. As mentioned above, the terms "send toward," "receive from," and "cooperate with" (and variations thereof) include communication that may or may not involve communication through one or more intermediate devices or nodes. It is intended that any description referring to a DU should also be considered as referring to a network node supporting at least one of the DU functionality or Layer 2 protocols of a Radio Access Network (RAN). It is also intended that any description referring to a CU should also be considered as referring to a network node supporting at least one of the CU functionality or Layer 3 protocols of a Radio Access Network (RAN).

[0078] The following paragraphs describe various signals and operations. It will be understood that the signals described can have associated operations, and the operations described can have associated signals. Therefore, the signals described can also be operations, and the operations described can also be signals.

[0079] Prior to operation 601, the UE had already established a connection with the DU (i.e., the source DU) of the serving cell that supports the UE, and had already established a (logical) connection with the CU that supports the DU.

[0080] At operation 601, the UE sends an L3 measurement report to the source DU, and the source DU receives the L3 measurement report from the UE. Those skilled in the art will understand that the L3 measurement report may, for example, include an average measurement sample of a reference signal for the serving cell. The L3 measurement report may indicate, for example, that the UE is approaching the edge of a cell and therefore a handover procedure should be initiated. At operation 602, the source DU forwards the L3 measurement report by sending it to the CU, and the CU receives the L3 measurement report from the source DU. At operation 603, the CU makes a handover (HO) decision / target cell preparation decision based on the L3 measurement report regarding whether handover should be prepared. In the illustrated implementation, the CU decides that handover should be prepared.

[0081] At operation 604, the CU sends a UE context establishment request to the target DU to prepare the target DU for handover by establishing a UE context in the target DU. The target DU receives the UE context establishment request from the CU and establishes the UE context. At operation 605, the target DU provides confirmation by sending a UE context establishment response to the CU, and the CU receives the UE context establishment response from the target DU. Although only one target DU is shown, more than one target DU may exist if multiple candidate cells are present. The operations at 604 and 605 can be used for each target DU as well as for multiple candidate cells. The following description will refer to candidate cells to indicate that one or more candidate cells may exist, and where appropriate, the target DU supporting the candidate cell will be referred to. If the target DU and the source DU are supported by different CUs, the CUs may communicate using the Xn interface. For convenience, only one CU (the CU supporting the source DU) is shown, but the disclosed technical intent also applies to multi-CU scenarios.

[0082] At operation 606, the CU sends a UE context modification request to the source DU for modifying the UE context in the source DU (if necessary) and for configuring target cell information (e.g., target cell RS configuration, activated or indicated TCI state, etc.). The source DU receives the UE context modification request from the CU, modifies the UE context (if necessary), and receives the target cell information. At signal 607, the source DU provides confirmation by sending a UE context modification response to the CU, and the CU receives the UE context modification response from the source DU.

[0083] At operations 604 to 607, the CU, target DU, and source DU can coordinate with each other regarding the timing advance acquisition and configuration of candidate cells. Timing advance refers to information used by the UE to time its uplink transmissions toward the network node to arrive at the network node in alignment with the reception time window. This information may be referred to herein as a timing advance value or TA value, and the process of acquiring the timing advance value may be referred to herein as timing advance acquisition, TA acquisition, acquiring timing advance, or acquiring TA (or variations thereof). As described above, the term "acquisition" (and variations thereof) includes acquisition in a first instance or re-acquisition after a first instance. In an implementation, the source DU and target DU can coordinate (via the CU) regarding the method used by the UE to acquire the TA. In an implementation, the UE can acquire a separate TA value for each candidate cell.

[0084] In implementations, TA can be acquired based on random access (RA) procedures (CFRA or CBRA), such as, but not limited to, RA procedures commanded by the physical downlink control channel (PDCCH), UE-triggered RA procedures, and / or RA procedures triggered by higher layers from network nodes (other than L3 handover commands), etc. In implementations, TA can also be acquired based on non-RA procedure methods, such as, but not limited to, TA acquisition based on sounding reference signals (SRS), mechanisms based on receive timing differences (such as those in LTE), and / or UE-based TA measurements, etc. Such RA-based and non-RA-based methods for TA acquisition are within the scope of this disclosure.

[0085] At operation 608, the CU creates an RRC reconfiguration message, which includes measurement configuration for L1 cell change, configuration of the prepared cell, and TA acquisition configuration and triggering for the candidate cell. In an implementation, the RRC reconfiguration message may include TA configuration if CU involvement is required later (during the execution phase). TA configuration may, for example, specify the method for the UE to acquire TA. In an implementation, the TA acquisition method may be configured / triggered by the CU (coordinated with the source DU) based on L3 measurements.

[0086] At signal 609, the CU uses downlink (DL) RRC message transmission to send an RRC reconfiguration message to the source DU, and the source DU receives the RRC reconfiguration message from the CU. As mentioned above, the RRC reconfiguration message may include the TA configuration and activated or indicated TCI status information, as well as cell handover criteria. At signal 610, the source DU sends an RRC reconfiguration message to the UE to forward it to the UE, and the UE receives the RRC reconfiguration message from the source DU. The UE performs reconfiguration based on the RRC reconfiguration message. At operation 611, the UE responds by sending an RRC reconfiguration completion message to the source DU using uplink (UL) RRC message transmission, and the source DU receives the RRC reconfiguration completion message from the UE. At operation 612, the source DU sends an RRC reconfiguration completion message to the CU to forward it to the CU, and the CU receives the RRC reconfiguration completion message from the source DU. In the implementation, signals 609 to 612 can be described as part of a logical connection between the UE and the CU, such that the CU sends an RRC message to the UE, and the UE receives an RRC message from the CU.

[0087] In the implementation plan, the signals and operations 601 to 612 described above can be referred to as the preparation phase. The execution phase follows the preparation phase.

[0088] During the execution phase, the UE provides periodic L1 measurement reports based on its configuration. Those skilled in the art will understand L1 measurement. L1 measurement can measure the signal power of a list of reference signals configured by the network. For example, L1 measurement can measure the signal power of a reference signal corresponding to an SSB in an activated TCI state. At operation 613, the UE periodically sends L1 measurement reports to the source DU, and the source DU receives periodic L1 measurement reports from the UE. In some cases, the reported L1 measurement report may be an L3 measurement.

[0089] At operation 614, the source DU determines whether to trigger the UE to acquire the TA for the set of candidate cells (i.e., the candidate cells configured for handover by the CU at operation 608) based on the received L1 measurement report.

[0090] At operation 615, the source DU sends a TA acquisition command to the UE, and the UE receives the TA acquisition command. The UE performs TA acquisition for the candidate cell using the TA acquisition method specified in the RRC reconfiguration message of operation 608. As described above, the TA can be acquired based on a random access (RA) procedure (CFRA or CBRA), such as, but not limited to, a RA procedure commanded by the physical downlink control channel (PDCCH), a UE-triggered RA procedure, and / or a higher-layer RA procedure triggered from a network node (other than the L3 handover command), etc. In implementations, the TA can be acquired based on a non-RA procedure method, such as, but not limited to, TA acquisition based on a sounding reference signal (SRS), a mechanism based on receive timing difference (such as those in LTE), and / or UE-based TA measurement, etc. Such RA-based and non-RA-based methods for TA acquisition are within the scope of this disclosure. After operation 615, if the TA acquisition procedure is successful, the UE may have a TA value for the candidate cell before cell handover is triggered. If the TA acquisition procedure is unsuccessful, the UE will not have a TA value for the candidate cell.

[0091] At operation 616, the UE sends a random access preamble message to the target DU, enabling the target DU to estimate the TA between the UE and the target DU. After the target DU receives the random access preamble message, at operation 617, the CU sends a random access response message to the source DU, and the source DU receives the random access response message and sends it to the UE, which then receives the random access response message from the source DU.

[0092] At operation 618, the UE continues to report L1 measurements and periodically sends L1 measurement reports to the source DU, and the source DU receives periodic L1 measurement reports from the UE.

[0093] In the implementation scheme, signals and operations 613 to 618 may be collectively referred to as the execution phase. Following the execution phase, in some example implementations, several optional phases may be performed. A first option occurring after operation 618 may be performed at operations 619 to 624, while a second option occurring after operation 618 may be performed at operations 625 to 628.

[0094] For example, in the first optional phase operation 619 (option-1), pre-TCI activation occurs. For example, at operation 620, the source DU selects a potential target cell and its beam for pre-TCI state activation. At operation 621, the source DU sends a TCI state activation command (TCI activation for LTM) to the UE, and the UE receives the TCI activation command for LTM.

[0095] At operation 622, the UE tracks the associated QCL RS and obtains downlink time / frequency synchronization. At operation 623, the source DU determines the target cell to which the UE should be handed over. After determination, at operation 624, the source DU sends a MAC CE triggered cell change message to the UE, including the TA of the target cell and the TCI status indication, and the UE receives the MAC CE triggered cell change message.

[0096] In the second optional phase, operation 625 (option-2), simultaneous TCI activation and indication occur. For example, at operation 626, the source DU determines the target cell and beam to which the UE should be handed over. After determination, at operation 627, the source DU sends a MAC CE triggered cell change message to the UE, including the target cell's TA, TCI state activation, and TCI state indication, and the UE receives the MAC CE triggered cell change message. At operation 628, the UE tracks the associated QCL RS and obtains downlink time / frequency synchronization.

[0097] When option-1 (i.e., operations 619 to 624) or option-2 (i.e., operations 625 to 628) is completed, the UE performs a random access procedure at operation 629, as will be understood by those skilled in the art.

[0098] At operation 630, to initiate communication with the target DU, the UE uses its configured uplink (UL) resources to send an RRC reconfiguration complete message to the target DU, and the target DU receives the RRC reconfiguration complete message from the UE. At operation 631, the target DU uses UL RRC messaging to forward the RRC reconfiguration complete message to the CU to send an RRC reconfiguration complete message, and the CU receives the RRC reconfiguration complete message from the target DU. At operation 632, the CU sends a UE context release command / request to the source DU to release the UE context from the source DU, and the source DU receives the UE context release command / request from the CU. The source DU releases the UE context in response to the UE context release command / request. At operation 633, the source DU sends a UE context release complete message to the CU, and the CU receives the UE context release complete message from the source DU. The CU can then perform a path handover to the target DU, which is the new DU supporting the serving cell.

[0099] Figure 6 The signals and operations described herein are illustrative only, and variations are contemplated within the scope of this disclosure. For example, signals and operations may assume one TA value per Physical Cell ID (PCI). In implementations, to cover multi-TRP (Multiple Transmit / Receive Point) scenarios, the UE may be configured to and request multiple TA values ​​for a PCI, such as different TA values ​​for different sets of TCI states. In implementations, signals and operations may include... Figure 6 Other signals and operations not shown. In an implementation, signals and operations may not include... Figure 6 Each signal and operation is shown in the diagram. In the implementation, the signals and operations can be coupled with... Figure 6 The different sequences of implementations shown are envisioned. Such and other implementations are contemplated within the scope of this disclosure.

[0100] In some examples, switching the TCI state from one active TCI state to add another TCI state can cause delays. For example, Figure 7 This is a graph showing the example TCI state switching delay used for adding TCI states to the active TCI state list.

[0101] like Figure 7 As shown, the delay can depend on whether the target TCI state is already on the active TCI state list. If the target TCI state is not on the active TCI state list, the UE is required to synchronize with the corresponding SSB, which is why the delay involves T. 第一SSB and T SSB-proc The reason, the T 第一SSB This refers to the time between the MACCE command of an SSB with a target TCI state in QCL-Type A or QCL-Type C and the first SSB transmission, and the T SSB-proc This refers to the SSB processing delay. The SSB periodicity can vary in different configurations (e.g., 160 ms). Therefore, the first SSB, which is in the correct QCL relationship with the target TCI state, may occur at most 160 ms after the UE has decoded the MAC CE command. When the target TCI state is already on the active TCI state list, synchronization with the first SSB is not required, and the delay is significantly shorter. This is in... Figure 7 As shown in the diagram, if the target TCI state is already on the list of active TCI states, then T can be omitted in the delay. 第一SSB and T SSB-proc .

[0102] Therefore, to reduce the aforementioned latency, in the case of LTM, a beam indication (TCI state) associated with the target cell can be provided as part of the cell handover command, which the UE will use to communicate with the target cell. To provide the TCI state indication, such TCI states can be activated early so that the UE acquires time / frequency synchronization earlier (while connecting to the source cell), which can reduce handover interruptions. In various implementations, such TCI states can be activated early so that the UE begins acquiring time / frequency synchronization after receiving the cell handover command or after connecting to the new target cell. In one example, connecting to the new target cell may mean that the UE has already sent an RRC message to the target cell (e.g., RRC reconfiguration completed). This can reduce handover interruptions or increase throughput when entering a new cell (i.e., the UE can be scheduled with higher-order modulation and / or use higher-gain beams, etc.). Each candidate target cell can be prepared with a set of TCI states given in the LTM configuration given outside the current serving cell or cell configuration.

[0103] Since one of the current serving cells (such as an SCell, secondary cell) can also be selected as a candidate target cell for cell handover (e.g., as a target PCell), the TCI state may already be activated based on its serving cell configuration for the handover. Therefore, TCI state activation for cell handover using the LTM configuration for the currently active serving cell may cause unnecessary activation latency (and / or activation signaling), and minimizing activation latency and signaling overhead may be desirable in such scenarios. Additionally, the UE may include information about both the TCI state from the intra-cell activation pool and the TCI state in the LTM TCI state pool. In some example implementations, the TCI state in the intra-cell pool may be considered as the "first TCI state" in a "first TCI state pool," while the TCI state in the LTM TCI state pool may be considered as the "second TCI state" in a "second TCI state pool." Therefore, the TCI state pools are inherently different configurations (e.g., they can be configured separately) and may include independently configured (same or different) sets of TCI states. A TCI state pool can refer to a list of TCI states that can be activated for beam indication for at least one of the activated TCI states (these are the activated TCI states). The pool or list of TCI states can be configured using RRC signaling. A pool of TCI states can be a combined list of DL / UL TCI states (i.e., for both uplink and downlink communication). A pool of TCI states can also be a list of individual DL or UL TCI states. An intra-cell activation pool can refer to a list of TCI states that can be activated for beam indication for intra-cell communication (e.g., for beam management). An LTM TCI state pool can refer to a list of TCI states that can be activated for beam indication for LTM cell handover (e.g., for beam indication before, during, or after a cell handover command). For a pool of TCI states, if only one TCI state (a single TCI state) is activated, that state is also the indicated TCI state. In some cases, if the TCI state is indicated but not activated, the indicated TCI state can also be changed to an activated TCI state.

[0104] Figure 8 This is a diagram of an example implementation of signaling and operation 800 between the UE, CU, source cell and candidate cell during the LTM TCI activation process according to an aspect shown in this disclosure.

[0105] The following paragraphs describe various signals and operations. It will be understood that the described signals may have associated operations, and the described operations may have associated signals. Therefore, the described signals may also relate to operations, and the described operations may also relate to signals. Additionally, in some example implementations, the terms source cell and candidate cell may be used interchangeably with the terms "source DU" and "candidate DU". Furthermore, as used herein, PDCCH may refer to the Physical Downlink Control Channel, PDSCH may refer to the Physical Downlink Shared Channel, PUSCH may refer to the Physical Uplink Shared Channel, PUCCH may refer to the Physical Uplink Control Channel, DMRS may refer to the Demodulation Reference Signal, and TRS may refer to the Tracking Reference Signal.

[0106] At operation 801, the UE establishes a connection with the source cell C0 (e.g., the serving cell supporting the UE and the source DU that has already established a (logical) connection with the CU supporting the DU). The UE includes the ability to determine the TCI activation associated with a TCI state pool based on the activated TCI states associated with different TCI state pools. The network may be aware of this capability as part of the UE capability indication. In some example implementations, the UE may indicate its ability to support activating TCI states in one TCI state pool based on one or more activated TCI states in another TCI state pool.

[0107] At operation 802, measurement reports are shared among the UE, source cell C0, candidate cell C1, and CU. In some example implementations, sharing may include the above-described... Figure 6 The operations described are similar to 601 (L3 Measurement Report Message) and 602 (UL RRC Message Transmission).

[0108] Therefore, based on the measurement report (e.g., L3 measurement report), at operation 803, the CU performs LTM preparation and provides the UE with an LTM configuration including the TCI states of candidate cells. As described above, the UE also includes TCI states configured under the current serving cell configuration for intra-cell / inter-cell beam management (BM). This may be referred to as the BM TCI pool. The UE is also configured to allow / configure / enable activation of BM TCI based on activated TCI states in another TCI state pool (e.g., the LTM TCI state pool) for BM TCI activation. Alternatively or additionally, the UE is configured to allow / configure / enable activation of LTM TCI based on activated TCI states in another TCI state pool (e.g., the BM TCI state pool).

[0109] Different types of configuration options can be used (e.g., based on TA to obtain status, L1 measurement quality, or a set of candidate cells that are indicated to allow this).

[0110] For example, it can be configured for the UE (e.g., in RRC) whether TCI state activation from one TCI state pool of configured TCI states can be based on an already activated TCI state in another TCI state pool. For example, for LTM, in the LTM preparation phase described below, it can be configured for the UE in the RRC (reconfiguration) message whether TCI activation for an LTM candidate cell can be based on an already activated TCI state in another TCI state pool (configured for the intra-cell / inter-cell BM of the current serving cell).

[0111] In various implementations, the UE can be configured to determine the activation of one or more TCI states based on the activated TCI states in another TCI state pool (e.g., a cell-specific or cell set-specific TCI state pool) for which LTM candidate cells.

[0112] In various implementations, the MAC-CE activation command may contain a common indication for all included TCI states or a separate indication for each included TCI state in the MAC-CE, i.e., whether activation of one or more TCI states in one TCI state pool can be used to activate one or more TCI states in another TCI state pool. For example, the MAC-CE activation command may contain an indication that activation of one or more TCI states in the LTM TCI state pool can be used to activate one or more TCI states in the intra-cell / inter-cell BM TCI state pool. Conversely, the MAC-CE activation command may contain an indication that activation of one or more TCI states in the intra-cell / inter-cell BM TCI state pool can be used to activate one or more TCI states in the LTM TCI state pool.

[0113] In various implementations, the message providing the cell handover command (e.g., MAC-CE) may include an indication of whether the UE can consider the activation of a TCI state in another TCI state pool based on the activation of a TCI state in one TCI pool.

[0114] In various implementations, when activation and indication are carried out simultaneously via a cell handover command, the MAC-CE cell handover command may contain a common indication for all included TCI states or a separate indication for each included TCI state in a TCI state pool within the MAC-CE, i.e., whether activation can be based on an activated TCI state in another TCI state pool.

[0115] In various implementations, the UE can be configured to consider activation for a candidate cell or downlink RS for which TA is available or for which a TA acquisition procedure has already been performed, based on prior activation in another TCI state pool. The TA acquisition procedure may also include sending PRACH transmissions to the candidate cell based at least on a PDCCH command from the network.

[0116] In various implementations, the UE can be configured to consider activation (of one or more TCI states in another TCI state pool) based on prior activation of a TCI state pool for candidate cells or downlink RSs based on L1 measurements. As an example, a DL RS used for L1 measurements can be configured as a DL RS in a TCI state (i.e., a TCI state includes / contains DL RSs that are also used for L1 measurements). As an example, DL RSs for which L1 measurements are above a certain quality (a configured threshold) or for which changes in L1 measurements since the last activation (associated with the first TCI state pool) have not exceeded a certain threshold are considered. As an example, the threshold can be expressed in dB (e.g., 3 dB, 6 dB, etc.). The threshold can be configured by the network (e.g., via RRC signaling). In one example, the L1 measurement may need to be a reported measurement (e.g., reported at least once) to be considered for activation.

[0117] In various implementations, the activation configuration can be configured to be applied on a per-TCI-state basis (in RRC signaling) or as a set of TCI-states in the TCI-state pool (e.g., via RRC signaling).

[0118] In some example implementations, the source cell can indicate to the target cell in the handover-related signaling which TCI state / QCL sources are considered active from the UE's perspective.

[0119] In some example implementations, the source cell can indicate to the target cell in the handover-related signaling whether, from the UE's perspective, a TCI state / QCL source in a TCI state pool is considered to be activated based on the activation of another TCI state pool.

[0120] At operation 804, the source cell sends a MAC-CE activation message for the intra-cell / inter-cell beam management (BM) to the UE, and the UE receives the MAC-CE activation message for the intra-cell / inter-cell BM (i.e., activation of the TCI state for beam management within the cell / serving cell). The MAC-CE activation message for the intra-cell / inter-cell BM includes activating the TCI state from the TCI state pool of one of the serving cells (e.g., TCI state x from L0). Therefore, at operation 805, the UE tracks the QCL source RS (included in the TCI state) and acquires time / frequency synchronization. Once acquired, at operation 806, after activating the handover delay, the TCI state (e.g., TCI state x) can be used (or can be used for beam indication).

[0121] At operations 807 to 808, the UE continues to report L1 measurements and periodically sends L1 measurement reports to the source cell, and the source cell receives periodic L1 measurement reports from the UE.

[0122] Based on the received L1 measurement, at operation 809, the source cell can decide to activate the TCI state (e.g., TCI state y) associated with the candidate cell (e.g., candidate cell C1). TCI state y can be selected from the list of LTM TCI states in the LTM TCI state pool given for candidate cell C1. The source cell sends a MAC-CE activation command for LTM to the UE, and the UE receives the MAC-CE activation command for LTM. The MAC-CE command can instruct the UE to activate TCI state y.

[0123] Therefore, when the UE receives a MAC-CE activation for one or more TCI states in the LTM TCI state pool from the serving cell (source cell), it can determine that at least one of the QCL source RSs for TCI state y (e.g., the second TCI state) is also the QCL source RS for TCI state x (e.g., the first TCI state) that has been activated but belongs to a different TCI state pool (i.e., the intra-cell / inter-cell BM TCI state pool). In other words, when the QCL reference signal for the first TCI state is the same as the QCL reference signal for the second TCI state, the QCL reference signal for the first TCI state can be considered related / associated / share common properties with the QCL reference signal for the second TCI state.

[0124] In one implementation, upon receiving a MAC-CE activation for one or more (second) TCI states in the LTM TCI state pool from the serving cell (source cell), the UE can determine whether at least one of the LTM TCI states shares the same property (or more generally, is associated with) one or more (first) TCI states in the intra-cell TCI state pool. If the UE determines that they share the same property, e.g., the same QCL source RS, the UE can determine that one or more (second) TCI states are active. Activation of one or more second TCI states can be performed when determining whether the TCI states (first and second TCI states) share the same property (i.e., upon receiving an activation message for a second TCI state). In some examples, activation can be performed upon connection to a target cell (and determination of whether the TCI states share at least one common property). In one example, activation (and property determination) can be performed upon receiving a cell handover command for a target cell associated with one or more first TCI states.

[0125] In other words, when the QCL reference signal of the first TCI state and the QCL reference signal of the second TCI state are defined the same or identical (signal), the QCL reference signal of the first TCI state can be considered to be related to / associated with / share common properties with the QCL reference signal of the second TCI state.

[0126] In various implementations, if the first TCI state and the second TCI state (in the first and second pools) share a common property, the TCI state activation delay can be reduced because the synchronization delay described above can be reduced or even eliminated. In one example, the first TCI state can be activated, which allows the UE to determine that if the first and second TCI states share at least one common property / association, the second TCI state will be activated. In one example, the first TCI state can be activated in a first message (e.g., an activation MAC CE associated with the first TCI state), and the second TCI state can be activated in a second message (e.g., an activation MAC CE associated with the second TCI state). If the first and second TCI states share at least one common property / association, receiving the second message allows the UE to determine that the second TCI state is activated without activation delay or with reduced activation delay. After a cell handover has been performed to the cell associated with the second TCI state, the activated (second) TCI can be further assumed to be a known TCI state / in the active TCI state list for beam indication. A known TCI state / in the list of active TCI states can refer to a UE being able to receive downlink channels (PDSCH / PDCCH) with reduced latency. One or more first TCI states and one or more second TCI states may exist. A first TCI state may refer to a cell / serving cell beam management TCI state. A second TCI state may refer to an LTM TCI state. In other words, upon receiving an activation message for a first TCI state, the activation of the first TCI state can be used to determine the activation of the second TCI state (the first and second TCI states may have an activation delay of X milliseconds / slot). Alternatively, upon receiving a second activation message for a second TCI state (where the activation of the first TCI state has already been provided in the first message), the activation of the first TCI state can be used to determine the activation of the second TCI state, thereby causing the UE to either not apply (e.g., X milliseconds / slot) activation / handover latency or apply a reduced activation / handover latency. Similarly, a first TCI state can be determined to be activated based on a second TCI state, as described herein.

[0127] In some examples, if a TCI state (or multiple TCI states) is known (based on activation), it can be assumed that reception and / or transmission of at least the downlink or uplink channel is ready, regardless of the (additional) delay component based on DL RS measurements associated with the TCI state (e.g., SSB). In one example, this is in Figure 7 As shown in the diagram, if the target TCI state is already on the list of active TCI states, then T can be omitted in the delay. 第一SSB and T SSB-proc .

[0128] In various implementations, when the QCL reference signal of the first TCI state and the QCL reference signal of the second TCI state share the same one or more of the QCL properties (e.g., one or more of Doppler spread, Doppler shift, delay spread, or average delay), the QCL reference signal of the first TCI state can be considered to be related to / associated with / share common properties with the QCL reference signal of the second TCI state.

[0129] In various implementations, when the QCL reference signal of the first TCI state and the QCL reference signal of the second TCI state are in QCL of type D (spatial relationship, e.g., same beam), the QCL reference signal of the first TCI state can be considered associated with / correlated with the QCL reference signal of the second TCI state. For example, the QCL reference of the first TCI state may be a TRS, and the QCL reference signal associated with the second TCI state may be an SSB, where the TRS and SSB are in QCL of type D. In other words, if the first TCI state is already active and the second TCI state shares the same QCL source RS (e.g., SSB), then the second TCI state is also considered active.

[0130] In various implementations, if the QCL source RS of the first TCI state (the TCI state may include TRS-CSI-RS) shares the same QCL source (SSB or CSI-RS) with the second TCI state, then all TCI states with the target RS (such as one or more TCIs that include TRS and have the same source RS) are considered to be active TCI states in all TCI state pools or at least in multiple TCI state pools.

[0131] In various implementations, if the QCL source RS (TCI state may include TRS-CSI-RS or SSB) of the first TCI state and the QCL source RS (TCI state may include TRS-CSI-RS or SSB) of the second TCI state are the same signal, then the UE can determine that the TCI states share the same property. The same property may refer to the same QCL source RS (SSB or CSI-RS).

[0132] In various implementations, if the QCL source of the QCL source RS in the first TCI state (the QCL source RS's QCL source could be, for example, an SSB) is the same signal as the QCL source RS in the second TCI state (the QCL source RS's QCL source could be, for example, an SSB), then the UE can determine that the TCI states share the same property / relatedness. The same property can refer to the QCL source RS (SSB or CSI-RS). In other words, a TCI state can include a QCL source RS (e.g., TRS-CSI-RS) with another QCL source RS (such as an SSB (primary QCL source)). An example of a QCL relationship (or QCL chain) could be PDCCH DMRS->TRS-CSI-RS->SSB. The QCL source RS in the TCI state can be a source RS used for a target signal, such as PDCCH / PDSCH / PUSCH / PUCCH DMRS.

[0133] At operation 811, the UE and the source cell assume that TCI state y is activated and ready for indication. At operation 812, the source cell makes a handover decision to candidate cell C1 with TCI state y. Once the decision is made, the source cell sends an LTM handover command with a TCI state indication including TCI state y to the UE at operation 813, and the UE receives the LTM handover command with a TCI state indication including TCI state y. If there is no prior TCI activation for TCI state y for LTM, simultaneous activation and indication can be performed as described above.

[0134] At operation 814, to initiate communication with the candidate cell, the UE uses its configured uplink (UL) resources to send an RRC reconfiguration complete message to the target cell, and the candidate cell receives the RRC reconfiguration complete message from the UE. At operation 815, the candidate cell uses UL RRC message forwarding to forward the RRC reconfiguration complete message to the CU, and the CU receives the RRC reconfiguration complete message from the candidate cell. The CU can then perform a path handover to the candidate cell as its serving cell.

[0135] Figure 8 The signals and operations described are illustrative only, and variations are contemplated within the scope of this disclosure. In embodiments, signals and operations may include... Figure 8 Other signals and operations not shown. In an implementation, signals and operations may not include... Figure 8 Each signal and operation is shown in the diagram. In the implementation, the signals and operations can be coupled with... Figure 8 The different sequences of implementation shown are envisioned. Such and other implementations are contemplated to be within the scope of this disclosure.

[0136] Now for reference Figure 9 The diagram illustrates a block diagram of example components of a UE or network device. The device includes an electronic storage device 910, a processor 920, a memory 950, and a network interface 940. The various components can be communicatively coupled to each other. The processor 920 can be and may include any type of processor, such as a single-core central processing unit (CPU), a multi-core CPU, a microprocessor, a digital signal processor (DSP), a system-on-a-chip (SoC), or any other type of processor. The memory 950 can be a volatile type of memory (e.g., RAM) or a non-volatile type of memory (e.g., NAND flash memory). The memory 950 includes processor-readable instructions that can be executed by the processor 920 to cause the device to perform various operations, including those mentioned herein, such as... Figure 6 and Figure 8 The operation.

[0137] Electronic storage device 910 can be and includes any type of electronic storage device for storing data, such as hard disk drives, solid-state drives, and / or optical disks, as well as other types of electronic storage devices. Electronic storage device 910 stores processor-readable instructions for causing the device to perform its operations, and stores data associated with such operations, such as data related to the 5G NR standard and other data. Network interface 240 can implement wireless networking technologies, such as 5G NR and / or other wireless networking technologies.

[0138] Figure 9 The components shown are merely examples, and those skilled in the art will understand that the device includes other components not shown, and may include multiple of any of the components shown. Such and other embodiments are contemplated to be within the scope of this disclosure.

[0139] Other embodiments of this disclosure include the following examples.

[0140] Example 1.1. A method comprising: The user equipment (UE) connected to the first cell receives the activation of the first TCI state in the first Transmission Configuration Indicator (TCI) state pool for the second cell and the second TCI state in the second TCI state pool for the second cell; The UE determines that the quasi-co-address (QCL) reference signal of the first activated TCI state shares one or more properties with the QCL reference signal of the second TCI state; The UE activates the second TCI state of the second cell based on the determination; and The UE uses the activated second TCI state of the second cell to perform cell handover to the second cell.

[0141] Example 1.2. The method as described in Example 1.1, wherein the UE maintains the activated second TCI state of the second cell when switching to the second cell.

[0142] Example 1.3. The method as described in Example 1.1, wherein the activation of the second TCI state of the second cell is determined after handover to the second cell.

[0143] Example 1.4. The method of any one of Examples 1.1 to 1.3, wherein the first activated TCI state in the first TCI state pool is associated with a beam management configuration for the second cell, and the second TCI state in the second TCI state pool is associated with a lower-layer triggered mobility (LTM) configuration for the second cell.

[0144] Example 1.5. The method of any one of Examples 1.1 to 1.3, wherein the first activated TCI state in the first TCI state pool is associated with a lower-layer triggered mobility (LTM) configuration for the second cell, and the second TCI state in the second TCI state pool is associated with a beam management configuration for the second cell.

[0145] Example 1.6. The method as described in any one of Examples 1.1 to 1.5, wherein the second cell is configured as an LTM candidate cell.

[0146] Example 1.7. The method as described in Example 1.6, wherein the second cell is configured as the serving cell.

[0147] Example 1.8. The method of any one of Examples 1.1 to 1.7, wherein the determination that the first activated TCI state and the second TCI share one or more properties includes determining that the quasi-co-address (QCL) reference signal of the first activated TCI state is equivalent to the QCL reference signal of the second TCI state.

[0148] Example 1.9. The method of any one of Examples 1.1 to 1.7, wherein the determination that the first activated TCI state and the second TCI share one or more properties includes determining that the quasi-co-address (QCL) reference signal of the first activated TCI state shares one or more properties with the QCL reference signal of the second TCI state.

[0149] Example 1.10. The method as described in Example 1.9, wherein one or more QCL properties include one or more of the following: Doppler spread, Doppler shift, delay spread, or average delay.

[0150] Example 1.11. The method as described in Example 1.9, wherein the QCL reference signal of the first activated TCI state and the QCL reference signal of the second TCI state share one or more properties, including that the QCL reference signal of the first activated TCI state includes the same QCL source reference signal (RS).

[0151] Example 1.12. The method as described in any one of Examples 1.1 to 1.11, wherein the activation of the first TCI state in the first TCI state pool associated with the second cell and the second TCI state in the second TCI state pool associated with the second cell is included in a Media Access Control (MAC) Control Element (CE) message.

[0152] Example 2.1. A user equipment (UE) comprising: A component for receiving, by the UE connected to the first cell, activation of a first TCI state in a first Transmission Configuration Indicator (TCI) state pool associated with the second cell and a second TCI state in a second TCI state pool associated with the second cell; A component for determining by the UE that a first activated TCI state and a second TCI state share one or more properties; Components for activating the second TCI state of the second cell by the UE based on the determination; and A component for the UE to perform cell handover to the second cell using the activated second TCI state of the second cell.

[0153] Example 2.2. A UE as described in Example 2.1, wherein the UE includes a component for maintaining the activated second TCI state of the second cell during handover to the second cell.

[0154] Example 2.3. The UE as described in Example 2.1, wherein the activation of the second TCI state of the second cell is determined after handover to the second cell.

[0155] Example 2.4. A UE as described in any one of Examples 2.1 to 2.3, wherein the first activated TCI state in the first TCI state pool is associated with a beam management configuration for the second cell, and the second TCI state in the second TCI state pool is associated with a lower-layer triggered mobility (LTM) configuration for the second cell.

[0156] Example 2.5. A UE as described in any one of Examples 2.1 to 2.3, wherein the first activated TCI state in the first TCI state pool is associated with a lower-layer triggered mobility (LTM) configuration for the second cell, and the second TCI state in the second TCI state pool is associated with a beam management configuration for the second cell.

[0157] Example 2.6. A UE as described in any one of Examples 2.1 to 2.5, wherein the second cell is configured as an LTM candidate cell.

[0158] Example 2.7. The UE as described in Example 2.6, wherein the second cell is configured as the serving cell.

[0159] Example 2.8. A UE as described in any one of Examples 2.1 to 2.7, wherein the determination that the first activated TCI state and the second TCI share one or more properties includes determining that the quasi-co-address (QCL) reference signal of the first activated TCI state is equivalent to the QCL reference signal of the second TCI state.

[0160] Example 2.9. A UE as described in any one of Examples 2.1 to 2.7, wherein the determination that the first activated TCI state and the second TCI share one or more properties includes determining that the quasi-co-address (QCL) reference signal of the first activated TCI state shares one or more properties with the QCL reference signal of the second TCI state.

[0161] Example 2.10. A UE as described in Example 2.9, wherein one or more QCL properties include one or more of the following: Doppler spread, Doppler shift, delay spread, or average delay.

[0162] Example 2.11. The UE as described in Example 2.9, wherein the QCL reference signal of the first activated TCI state and the QCL reference signal of the second TCI state share one or more properties, including that the QCL reference signal of the first activated TCI state includes the same QCL source reference signal (RS).

[0163] Example 2.12. A UE as described in any one of Examples 2.1 to 2.11, wherein the activation of the first TCI state in the first TCI state pool associated with the second cell and the second TCI state in the second TCI state pool associated with the second cell is included in a Media Access Control (MAC) Control Element (CE) message.

[0164] Example 3.1. A device comprising: A component for sending a first message to a user equipment (UE) by a first cell based on one or more properties shared by a first activated TCI state in a first Transmission Configuration Indicator (TCI) state pool associated with a second cell and a second TCI state in a second TCI state pool associated with the second cell, the first message including at least the first activated TCI state and the second TCI state. Components for beam management by the first cell using the first TCI state; and A component for sending instructions from the first cell to user equipment for handover to a lower layer of the second cell in a mobility (LTM) cell, the instructions including the second TCI state of the second cell.

[0165] Example 3.2. The device as described in Example 3.1, wherein the instruction for the LTM cell handover includes a command for handover to the LTM cell of the second cell.

[0166] Example 3.3. The device as described in Example 3.1, wherein determining that the first activated TCI state and the second TCI state share one or more properties includes determining that the quasi-co-address (QCL) reference signal of the first activated TCI state is equivalent to the QCL reference signal of the second TCI state.

[0167] Example 3.4. The device as described in Example 3.1, wherein determining that the first activated TCI state and the second TCI share one or more properties includes determining that the quasi-co-address (QCL) reference signal of the first activated TCI state shares one or more properties with the QCL reference signal of the second TCI state.

[0168] Example 3.5. A device as described in Example 3.4, wherein one or more QCL properties include one or more of the following: Doppler spread, Doppler frequency shift, delay spread, or average delay.

[0169] Example 3.6 A device as described in Example 3.4, wherein the QCL reference signal of the first activated TCI state and the QCL reference signal of the second TCI state share one or more properties, including that the QCL reference signal of the first activated TCI state includes the same QCL source reference signal (RS).

[0170] Example 3.7. The device as described in any one of Examples 3.1 to 3.6, wherein the first activated TCI state in the first TCI state pool is associated with a lower-layer triggered mobility (LTM) configuration for the second cell, and the second TCI state in the second TCI state pool is associated with a beam management configuration for the second cell.

[0171] Example 3.8. The device as described in any one of Examples 3.1 to 3.7, wherein the second cell is configured as an LTM candidate cell.

[0172] Example 3.9 The device as described in any one of Examples 3.1 to 3.8, wherein the second cell is configured as the serving cell.

[0173] Example 3.10 The device as described in any one of Examples 3.1 to 3.9, wherein the first message is a Media Access Control (MAC) Control Element (CE) message.

[0174] The embodiments and aspects disclosed herein are examples of this disclosure and may be embodied in various forms. For example, although some embodiments herein are described as separate embodiments, each of the embodiments herein may be combined with one or more of the other embodiments herein. Therefore, the specific structural and functional details disclosed herein should not be construed as limiting, but only as the basis of the claims and as a representative basis for teaching those skilled in the art to adopt this disclosure in various ways in any reasonably detailed structure. Throughout the description of the drawings, similar reference numerals may refer to similar or identical elements.

[0175] For example, the scenario described above is when the UE receives an active TCI activation command containing one or more active TCI states associated with a first TCI state index associated with a first configured TCI state pool. One or more second TCI states associated with a second TCI pool can be considered to be activated after at least one QCL source reference signal of the second TCI state in the second pool is associated with the QCL reference signal of one or more first activated TCI states in the first TCI state pool.

[0176] In some example implementations, the first TCI state pool may be a TCI state pool associated with one of the currently serving cells, and the second TCI state pool may be a TCI state pool configured for LTM candidate cells.

[0177] In some example implementations, the first TCI state pool may be a TCI state pool configured for an LTM candidate cell, and the second configured TCI state pool may be a TCI state pool associated with one of the currently serving cells.

[0178] In some example implementations, if the UE is configured with one or more TCI state pools for the serving cell and another TCI state pool for LTM, then when activating a TCI state for an LTM candidate cell, if the target TCI state is on the list of active TCI states belonging to any of the configured TCI state pools, then synchronization with SSBs that are in QCL relationship with the same target TCI state may not be considered during TCI state activation or LTM cell handover delay.

[0179] According to this disclosure, the phrases “on one hand,” “in all aspects,” “in various aspects,” “in some aspects,” or “in other aspects” can all refer to one or more of the same or different aspects. The phrase “multiple” can refer to two or more.

[0180] According to this disclosure, the phrases “in one embodiment,” “in various embodiments,” “in multiple embodiments,” “in some embodiments,” or “in other embodiments” can all refer to one or more of the same or different embodiments. A phrase in the form “A or B” means “(A), (B), or (A and B).” A phrase in the form “at least one of A, B, or C” means “(A); (B); (C); (A and B); (A and C); (B and C); or (A, B, and C).” Any of the methods, programs, algorithms, or code described herein can be translated into or expressed in a programming language or computer program. As used herein, the terms "programming language" and "computer program" include any language used to specify instructions to a computer, and include (but are not limited to) the following languages ​​and their derivatives: assembler, Basic, batch file, BCPL, C, C+, C++, Delphi, Fortran, Java, JavaScript, machine code, operating system command languages, Pascal, Perl, PL1, Python, scripting languages, Visual Basic, meta-languages ​​that specify the program itself, and all first-, second-, third-, fourth-, fifth-, or later generation computer languages. Databases and other data schemas are also included, as well as any other meta-languages. There is no distinction between interpreted, compiled, or languages ​​that use both compiled and interpreted methods. There is no distinction between a compiled version and a source version of a program. Therefore, where a programming language can exist in more than one state (such as source, compiled, object, or linked), a reference to a program is a reference to any or all of these states. References to a program can encompass the actual instructions and / or the intent of those instructions.

[0181] While various aspects of this disclosure have been shown in the accompanying drawings, this disclosure is not intended to be limited thereto, and is intended to be as broad as would be permitted in the art, and the specification should be interpreted accordingly. Therefore, the foregoing description should not be construed as restrictive, but merely as illustrative of particular aspects. Other modifications within the scope and spirit of the appended claims will be contemplated by those skilled in the art.

Claims

1. A method comprising: The user equipment (UE) connected to the first cell receives the activation of a first TCI state in a first configured Transport Configuration Indicator (TCI) state pool associated with the second cell and further receives the configuration of a second TCI state in a second TCI state pool associated with the second cell. The UE determines that the first activated TCI state and the second TCI state share one or more properties; The UE activates the second TCI state of the second cell based on the determination. as well as The UE performs a cell handover to the second cell, thereby maintaining the activated second TCI state of the second cell.

2. The method of claim 1, wherein the UE activates the second TCI state after receiving the activation for the first TCI state and before the cell handover, and maintains the activated second TCI state of the second cell during the handover to the second cell.

3. The method of claim 1, wherein the activation of the second TCI state of the second cell is determined after handover to the second cell.

4. The method of any one of claims 1 to 3, wherein the first activated TCI state in the first TCI state pool is associated with a beam management configuration for the second cell, and the second TCI state in the second TCI state pool is associated with a lower-layer triggered mobility (LTM) configuration for the second cell.

5. The method of any one of claims 1 to 3, wherein the first activated TCI state in the first TCI state pool is associated with a lower-layer triggered mobility (LTM) configuration for the second cell, and the second TCI state in the second TCI state pool is associated with a beam management configuration for the second cell.

6. The method of any one of claims 1 to 5, wherein the second cell is configured as an LTM candidate cell.

7. The method of claim 6, wherein the second cell is configured as a serving cell.

8. The method of any one of claims 1 to 7, wherein the determination that the first activated TCI state and the second TCI share one or more properties includes determining that the quasi-co-address (QCL) reference signal of the first activated TCI state is equivalent to the QCL reference signal of the second TCI state.

9. The method of any one of claims 1 to 7, wherein the determination that the first activated TCI state and the second TCI share one or more properties includes determining that the quasi-co-address (QCL) reference signal of the first activated TCI state shares one or more properties with the QCL reference signal of the second TCI state.

10. The method of claim 9, wherein one or more QCL properties include one or more of the following: Doppler spread, Doppler shift, delay spread, or average delay.

11. The method of claim 9, wherein the QCL reference signal of the first activated TCI state and the QCL reference signal of the second TCI state share one or more properties, including that the QCL reference signal of the first activated TCI state includes the same QCL source reference signal (RS).

12. The method of any one of claims 1 to 11, wherein the activation of the first TCI state in the first TCI state pool associated with the second cell and the second TCI state in the second TCI state pool associated with the second cell is included in a Media Access Control (MAC) Control Element (CE) message.

13. An apparatus comprising: At least one processor; as well as At least one memory, the at least one memory storing instructions, the instructions causing the device to perform at least the following when executed by the at least one processor: A first cell sends a first message to a user equipment (UE) based on a first activated TCI state in a first Transmission Configuration Indicator (TCI) state pool associated with a second cell and a second TCI state in a second TCI state pool associated with the second cell sharing one or more properties. The first message includes at least the first activated TCI state and further includes the second TCI state. The first cell uses the first TCI state for beam management; and The first cell sends an instruction to the user equipment for a handover to a lower layer of the second cell, triggering a mobility (LTM) cell handover, the instruction including the second TCI state of the second cell.

14. The apparatus of claim 13, wherein the instruction for the LTM cell handover includes a command for handover to the LTM cell of the second cell.

15. The device of claim 13, wherein determining that the first activated TCI state and the second TCI state share one or more properties includes determining that the quasi-co-address (QCL) reference signal of the first activated TCI state is equivalent to the QCL reference signal of the second TCI state.

16. The device of claim 13, wherein determining that the first activated TCI state and the second TCI share one or more properties includes determining that the quasi-co-address (QCL) reference signal of the first activated TCI state shares one or more properties with the QCL reference signal of the second TCI state.

17. The device of claim 16, wherein one or more QCL properties include one or more of the following: Doppler spread, Doppler frequency shift, delay spread, or average delay.

18. The device of claim 16, wherein the QCL reference signal of the first activated TCI state and the QCL reference signal of the second TCI state share one or more properties, including that the QCL reference signal of the first activated TCI state includes the same QCL source reference signal (RS).

19. The device of any one of claims 13 to 18, wherein the first activated TCI state in the first TCI state pool is associated with a lower-layer triggered mobility (LTM) configuration for the second cell, and the second TCI state in the second TCI state pool is associated with a beam management configuration for the second cell.

20. The device of any one of claims 13 to 19, wherein the second cell is configured as an LTM candidate cell.

21. The device of claim 20, wherein the second cell is configured as a serving cell.

22. The device as claimed in any one of claims 1 to 21, wherein the first message is a Media Access Control (MAC) Control Element (CE) message.

23. A user equipment (UE), comprising: At least one processor; as well as At least one memory, the at least one memory storing instructions, the instructions, when executed by the at least one processor, causing the device to perform at least the following: The user equipment (UE) connected to the first cell receives activation of a first TCI state in a first configured Transport Configuration Indicator (TCI) state pool associated with the second cell and further receives configuration of a second TCI state in a second TCI state pool associated with the second cell. The UE determines that the first activated TCI state and the second TCI state share one or more properties; The UE activates the second TCI state of the second cell based on the determination. as well as The UE performs a cell handover to the second cell, thereby maintaining the activated second TCI state of the second cell.

24. The UE of claim 23, further configured to activate the second TCI state after receiving the activation for the first TCI state and before the cell handover, and to maintain the activated second TCI state of the second cell during handover to the second cell.

25. The UE of claim 23, wherein the UE is configured to determine the activation of the second TCI state of the second cell after handover to the second cell.

26. The UE of any one of claims 23 to 25, wherein the first activated TCI state in the first TCI state pool is associated with a beam management configuration for the second cell, and the second TCI state in the second TCI state pool is associated with a lower-layer triggered mobility (LTM) configuration for the second cell.

27. The UE of any one of claims 23 to 25, wherein the first activated TCI state in the first TCI state pool is associated with a lower-layer triggered mobility (LTM) configuration for the second cell, and the second TCI state in the second TCI state pool is associated with a beam management configuration for the second cell.

28. The UE of any one of claims 23 to 27, wherein the second cell is configured as an LTM candidate cell.

29. The UE of claim 28, wherein the second cell is configured as the serving cell.

30. The UE of any one of claims 23 to 29, wherein the determination that the first activated TCI state and the second TCI share one or more properties includes determining that the quasi-co-address (QCL) reference signal of the first activated TCI state is equivalent to the QCL reference signal of the second TCI state.

31. The UE of any one of claims 23 to 29, wherein the determination that the first activated TCI state and the second TCI share one or more properties includes determining that the quasi-co-address (QCL) reference signal of the first activated TCI state shares one or more properties with the QCL reference signal of the second TCI state.

32. The UE of claim 31, wherein one or more QCL properties include one or more of the following: Doppler spread, Doppler frequency shift, delay spread, or average delay.

33. The UE of claim 32, wherein the QCL reference signal of the first activated TCI state and the QCL reference signal of the second TCI state share one or more properties, including that the QCL reference signal of the first activated TCI state includes the same QCL source reference signal (RS).

34. The UE of any one of claims 23 to 33, wherein the activation of the first TCI state in the first TCI state pool associated with the second cell and the second TCI state in the second TCI state pool associated with the second cell is included in a Media Access Control (MAC) Control Element (CE) message.

35. A processor-readable medium storing instructions that, when executed by at least one processor of a device, cause the device to perform at least the method as claimed in any one of claims 1 to 12.

36. A method comprising: A first cell sends a first message to a user equipment (UE) based on a first activated TCI state in a first Transmission Configuration Indicator (TCI) state pool associated with a second cell and a second TCI state in a second TCI state pool associated with the second cell sharing one or more properties. The first message includes at least the first activated TCI state and further includes the second TCI state. The first cell uses the first TCI state for beam management; and The first cell sends an instruction to the user equipment for a handover to a lower layer of the second cell, triggering a mobility (LTM) cell handover, the instruction including the second TCI state of the second cell.

37. A processor-readable medium storing instructions that, when executed by at least one processor of a device, cause the device to perform at least one method, the method comprising: A first cell sends a first message to a user equipment (UE) based on a first activated TCI state in a first Transmission Configuration Indicator (TCI) state pool associated with a second cell and a second TCI state in a second TCI state pool associated with the second cell sharing one or more properties. The first message includes at least the first activated TCI state and further includes the second TCI state. The first cell uses the first TCI state for beam management; and The first cell sends an instruction to the user equipment for a handover to a lower layer of the second cell, triggering a mobility (LTM) cell handover, the instruction including the second TCI state of the second cell.

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