Transmission configuration indicator (TCI) activation

Abstract

A method includes receiving, by a user equipment (UE) connected to a first cell, an activation of a first transmission configuration indicator (TCI) state for a first configuration (TCI) state pool associated with a second cell, and also receiving a configuration of a second TCI state for 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 attributes, and activates the second TCI state of the second cell based on the determination. The UE performs a cell transition to the second cell, maintaining an activated second TCI state of the second cell.

Description

Technical Field

[0001] Various example embodiments relate generally to wireless networks, and more particularly to transmission configuration indicator (TCI) states for mobility in wireless networks. Background Art

[0002] Wireless networks provide significant advantages for user mobility. The ability of users to stay connected while on the move not only provides advantages to users, but also provides greater efficiency and productivity to society as a whole. As user expectations for connection reliability, data speed, and device battery life become more demanding, the technology used for wireless networks must also keep up with these expectations. Therefore, there is a persistent interest in improving wireless networking technology. To this end, cellular standards have developed cell switching on various protocol layers: traditional layer 3 switching has existed for several generations. On this basis, conditional switching is introduced to improve the reliability of switching. Recent developments have considered a lower layer switching called layer 1 / layer 2 triggered mobility (LTM). Therefore, efforts to reduce delays during switching can be valuable. Summary of the invention

[0003] In one aspect of the present disclosure, a method for communication includes: receiving, by a user equipment (UE) connected to a first cell, activation of a first configured transmission configuration indicator (TCI) state pool associated with a second cell, and also receiving configuration of a second TCI state of a second TCI state pool associated with the second cell. Determining, by the UE, that the first activated TCI state and the second TCI state share one or more attributes, and based on the determination, activating the second TCI state of the second cell. The UE performs a cell transition to the second cell, 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, activation of a second TCI state of the second cell is determined after transitioning to the second cell.

[0006] In an aspect of the method, activation of a second TCI state of the second cell is confirmed after receipt of a cell switch command to switch the UE to the second cell.

[0007] In one aspect of the method, activation of the second TCI state of the second cell is confirmed after receipt and confirmation of a cell switch command to switch the UE to the second cell.

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

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

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

[0013] 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 a quasi-co-located (QCL) reference signal of the first activated TCI state is equivalent to a QCL reference signal of the second TCI state.

[0014] 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 a quasi-co-located (QCL) reference signal of the first activated TCI state shares one or more properties with a QCL reference signal of the second TCI state.

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

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

[0017] In one aspect of the method, activation of a first TCI state of a first TCI state pool associated with a second cell and a second TCI state of a second TCI state pool associated with the second cell is included in a media access control (MAC) control element (CE) message.

[0018] In one aspect of the present disclosure, a user equipment (UE) includes at least one processor and at least one memory storing instructions, which, when executed by the at least one processor, cause the device to perform at least any one of the aforementioned methods.

[0019] In one aspect of the present disclosure, a processor-readable medium stores instructions, which, when executed by at least one processor of a device, cause the device to perform at least any one of the aforementioned methods.

[0020] In one aspect of the present disclosure, a method for communication includes transmitting a first message by a first cell to a user equipment (UE), the first message including at least a first activated transmission configuration indicator (TCI) state of a first TCI state pool associated with a second cell and a second TCI state of a second TCI state pool associated with the second cell, based on a first activated TCI state and a second TCI state of a second TCI state pool associated with the second cell, The first cell uses the first TCI state to perform beam management, and transmits a cell switching instruction for lower layer triggered mobility (LTM) to the second cell to the user equipment, the instruction including the second TCI state for the second cell.

[0021] In one aspect of the method, the instructions for the LTM cell switch include a command for an LTM cell switch to a second cell.

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

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

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

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

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

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

[0030] In one aspect of the present disclosure, an apparatus for communication includes at least one processor and at least one memory, wherein the memory stores instructions, which, when executed by the at least one processor, cause the apparatus to perform at least any one of the aforementioned methods.

[0031] In one aspect of the present disclosure, a processor-readable medium stores instructions, which, when executed by at least one processor of a device, cause the device to perform at least any one of the aforementioned methods.

[0032] According to some aspects, the subject matter of the independent claims is provided. Some further aspects are defined in the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0034] Figure 1 is a diagram of an example embodiment of a wireless network between a network system and a user equipment device (UE) according to one illustrative aspect of the present disclosure;

[0035] Figure 2 is a diagram of an example embodiment for a wireless network to transmit and receive beams between a network device and a user equipment device (UE) according to one illustrative aspect of the present disclosure;

[0036] Figure 3 is a diagram of an example embodiment of UE scanning receive beams for synchronization signal block (SSB) bursts according to one illustrative aspect of the present disclosure;

[0037] Figure 4 is a diagram of an example embodiment of a Layer 1 / Layer 2 Triggered Mobility (LTM) scenario according to one illustrative aspect of the present disclosure;

[0038] Figure 5 is a diagram of an example embodiment of a contention-based random access procedure according to one illustrative aspect of the present disclosure;

[0039] Figure 6 is a diagram of an example embodiment of signals and operations between a UE, a central unit (CU), a source distributed unit (DU), and a target DU related to LTM according to one illustrative aspect of the present disclosure;

[0040] Figure 7 is a diagram of example transport configuration TCI states with example TCI state transition delays added for TCI states on an active TCI state list;

[0041] Figure 8 is a diagram of an example embodiment of signals and operations in an LTM TCI activation process between a UE, a CU, a source cell, and a candidate cell according to one illustrative aspect of the present disclosure; and

[0042] Fig. 9 is a diagram of an example embodiment of components of a UE or network device according to one illustrative aspect of the present disclosure. DETAILED DESCRIPTION

[0043] In the following description, certain specific details are set forth in order to provide a thorough understanding of the disclosed aspects. However, one skilled in the relevant art will recognize that the aspects may be practiced without one or more of these specific details or with other methods, components, materials, etc. In other instances, well-known structures associated with transmitters, receivers, or transceivers are not shown or described in detail to avoid unnecessarily obscuring the description of the various aspects.

[0044] Reference throughout this specification to "an aspect" or "aspects" means that a particular feature, structure, or characteristic described in conjunction with that aspect is included in at least one aspect. Thus, appearances of the phrases "in an aspect" or "in an aspect" throughout the specification are not necessarily all referring to the same aspect. Furthermore, in one or more aspects, the particular features, structures, or characteristics may be combined in any suitable manner.

[0045] The embodiments described in the present disclosure may be implemented in wireless network devices such as, but not limited to: Universal Mobile Telecommunications System (UMTS, 3G) utilizing Worldwide Interoperability for Microwave Access (WiMAX), Global System for Mobile Communications (GSM, 2G), GSM EDGE Radio Access Network (GERAN), General Packet Radio Service (GRPS), based on basic Wideband Code Division Multiple Access (W-CDMA), High Speed ​​Packet Access (HSPA), Long Term Evolution (LTE), Advanced LTE, Enhanced LTE (eLTE), 5G New Radio (5G NR), Advanced 5G, 6G (and higher) and 802.11ax (Wi-Fi6), and other wireless networking systems. The term "eLTE" herein means LTE evolution connected to a 5G core. LTE is also known as Evolved UMTS Terrestrial Radio Access (EUTRA) or Evolved UMTS Terrestrial Radio Access Network (EUTRAN).

[0046] Because the UE can travel from one area to another, a handover or mobility process may be important to support the continued communication of the UE with the network (without any interruption or at least minimal interruption). In an example, the UE may 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 the reference signals, and report those signal measurements to the network, so that a determination of the handover of the UE to a neighboring cell (e.g., when a degradation of signal quality is detected) can be made. The initiation of the handover can generally be performed by the network. In the example of 5G NR, the handover initiation or handover command can be signaled via upper layer signaling (e.g., layer 3 or radio resource control (RRC) signaling). Upper layer signaling may involve the network and therefore may have high latency. In various cases, the UE may benefit from a more efficient handover process triggered via lower layer signaling (e.g., L1 / L2 signaling), which has a lower latency than upper layer signaling. As used herein, handover triggered via lower layer signaling may be referred to as Lower Layer Triggered Mobility (LTM).In some instances, candidate cells for LTM may be referred to as LTM candidate cells.

[0047] As used herein, the term "cell switching" means and refers to any change of cell, whether the change is triggered via layer 1 signaling, layer 2 signaling and / or layer 3 signaling and / or other signaling. The cell switch may be for a terminal device in RRC connected mode, and therefore, the cell switch may involve two-way 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 target network node of the cell switch. The present disclosure mainly uses LTM as an example of cell switching, but it is intended and should be understood that the present disclosure can operate using layer 3 switching or any cell switch.

[0048] The present disclosure may use the term "serving cell" to refer to a network node or network device (or a portion thereof) serving a UE, may use 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 switch command, and may use the term "target cell" to refer to a network node or network device (or a portion thereof) that is a target of a cell switch command. In some examples, the LTM target may also be a serving cell (e.g., the target may be an "SCell", i.e., a secondary cell in carrier aggregation).

[0049] As used herein, the terms "send to," "receive from," and "cooperate with" (and variations thereof) include communications 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 reacquiring after a first instance. The term "connect" may refer to a physical connection or a logical connection.

[0050] Figure 1 1 is a diagram depicting an example of a wireless network between a network system 100 and a user equipment device (UE) 150. The network system 100 may include one or more network nodes 120, one or more servers 110, and / or one or more network equipment 130 (e.g., test equipment). The network node 120 will be described in more detail below. As used herein, the term "network device" may refer to any component of the network system 100, such as a server 110, a network node 120, a network device 130, any of the aforementioned components, and / or any other component of the network system 100. Examples of network devices include, but are not limited to, devices that implement various aspects of 5GNR, etc. The present disclosure describes embodiments relating to 5G NR and embodiments relating to various aspects defined by the Third Generation Partnership Project (3GPP). However, it is contemplated that embodiments related to other wireless networking technologies are included within the scope of the present disclosure.

[0051] The following description provides additional details of an example of a network node. In a 5G NR network, a gNodeB (also referred to as a gNB) may include, for example, a node that provides NR user plane and control plane protocol terminations to a UE and is connected to a 5G Core (5GC) via an NG interface, for example, in accordance with 3GPP TS 38.300 V16.6.0 (2021-06) section 3.2, which is incorporated herein by reference.

[0052] The gNB supports various protocol layers, e.g., Layer 1 (L1) - physical layer, Layer 2 (L2), and Layer 3 (L3).

[0053] NR's Layer 2 (L2) is divided into the following sublayers: Medium Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), and Service Data Adaptation Protocol (SDAP), where, for example:

[0054] oThe physical layer provides transport channels to the MAC sublayer;

[0055] o The MAC sublayer provides logical channels to the RLC sublayer;

[0056] o The RLC sublayer provides RLC channels to the PDCP sublayer;

[0057] o The PDCP sublayer provides radio bearers to the SDAP sublayer;

[0058] o The SDAP sublayer provides flows to the 5GC Quality of Service (QoS);

[0059] oControl channels include the Broadcast Control Channel (BCCH) and the Physical Control Channel (PCCH).

[0060] Layer 3 (L3) includes, for example, Radio Resource Control (RRC), for example, according to 3GPP TS 38.300 V16.6.0 (2021-06) Section 6, which is incorporated herein by reference.

[0061] The gNB Central Unit (gNB-CU) includes logical nodes that host, for example, the Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), and Packet Data Convergence Protocol (PDCP) protocols of the gNB, and the RRC and PDCP protocols of the en-gNB that control the operation of one or more gNB Distributed Units (gNB-DUs). The gNB-CU terminates the F1 interface with the gNB-DU. The gNB-CU may also be referred to herein as a CU, a central unit, a centralized unit, or a control unit.

[0062] The gNB distributed unit (gNB-DU) includes logical nodes such as the radio link control (RLC), media access control (MAC) and physical (PHY) layers that host, for example, a gNB or en-gNB, and its operation 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 as DU or distributed unit in this article.

[0063] As used herein, the term "network node" may refer to any one of a gNB, a gNB-CU or a gNB-DU or any combination thereof. A RAN (Radio Access Network) node or a network node (such as, for example, a gNB, a gNB-CU or a gNB-DU or a portion thereof) may be implemented using, for example, a device having at least one processor and / or at least one memory having processor-readable instructions ("program") configured to support and / or equip and / or process CU and / or DU related functions and / or features, and / or at least one protocol (sub) layer (e.g., layer 2 and / or layer 3) of a RAN (Radio Access Network). Different functional splits between central units and distributed units are possible.

[0064] The gNB-CU and gNB-DU parts may, for example, be co-located or physically separated. The gNB-DU may even be further divided into, for example, two parts, for example, one part including a processing device and one part including an antenna. The central unit (CU) may also be referred to as BBU / REC / RCC / C-RAN / V-RAN, O-RAN or a part thereof. The distributed unit (DU) may also be referred to as RRH / RRU / RE / RU or a part thereof. Hereinafter, in various example embodiments of the present disclosure, a network node supporting at least one of a central unit design function or a layer 3 protocol of a radio access network may be, for example, a gNB-CU. Similarly, a network node supporting at least one of a distributed unit design function or a layer 2 protocol of a radio access network may be, for example, a gNB-DU.

[0065] A gNB-CU may support one or more gNB-DUs. A gNB-DU may support one or more cells and may thus support a serving cell for a user equipment device (UE) or support a candidate cell for handover, dual connectivity and / or carrier aggregation, etc.

[0066] A user equipment device (UE) 150 may be or include a wireless or mobile device, a device having a radio interface for interacting with a RAN (Radio Access Network), a smart phone, a vehicle-mounted device, an IoT device or an M2M device, 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 to, together with the at least one processor, enable the device to perform at least certain operations, such as, for example, an RRC connection to the RAN. In an embodiment, the UE 150 may be configured to generate a message (e.g., including a cell ID) to be sent to the RAN via radio (e.g., to reach and communicate with a serving cell). In an embodiment, the UE 150 may generate and send and receive an RRC message 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.

[0067] Continue to refer Figure 1 In the example of a 5G NR network, the network system 100 provides one or more cells, which define the coverage area of ​​the network system 100. As described above, the network system 100 may include a gNB of a 5G NR network, or may include any other device configured to control radio communications and manage radio resources within a cell. As used herein, the term "resource" may refer to a radio resource, such as a resource block (RB), a physical resource block (PRB), a radio frame, a subframe, a time slot, a subband, a frequency region, a subcarrier, a beam, etc. In an embodiment, the network node 120 may be referred to as a base station.

[0068] Figure 1 An example is provided and only the network system 100 and the UE 150 are described. Those skilled in the art will appreciate that the network system 100 includes Figure 1 Components not shown, and it will be understood that other user equipment devices may communicate with the network system 100.

[0069] Figure 22 is a diagram of an example embodiment of a wireless network between a network device 210 and a user equipment device (UE) 150. The network device 210 is configured to form beams 220 in multiple directions, and the UE 150 is also configured to form beams 260 in multiple directions. As will be appreciated by those skilled in the art, the ability to beamform in multiple directions may be achieved by 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 separate arrays and / or by combining elements in an array in a manner that causes interference enhancement or interference destructiveness of signals at specific angles. Beamforming for transmission is achieved by controlling the phase and relative amplitude of the transmission signal at each radiating element in the array so as to create a desired pattern of interference enhancement and interference destructiveness in the desired wavefront. In contrast, beamforming for reception is achieved by combining information from different elements of the array in a manner that radiation in a target spatial region is preferentially observed.

[0070] In the example shown, the network device 210 (e.g., a gNodeB or a portion thereof) and the UE 150 may each be equipped with one or more antenna panels or antenna arrays having antenna elements that can be configured to perform beamforming in certain spatial directions and / or within certain spatial angular sectors or widths.

[0071] Continue to refer Figure 1 , various examples of beams 220 for network device 210 are shown, and various examples of beams 260 for UE 150 are shown. A consequence of using highly directional beams is that some of the network device beams 120 may not be used with some of the UE beams 160 due to large directional differences. Therefore, in an embodiment, UE 150 "scans" its beams 260, and network device 210 "scans" its beams 220 to determine which beam pairing has the highest signal power, and is therefore best available for communication. Due to various propagation conditions, a beam that is not perfectly directional may have the highest signal power. The scanning will be combined with Figure 3 After identifying such a beam pairing, UE 150 and network device 210 may initiate an access procedure for UE 150 to access network device 210 using the identified beam.

[0072] Figure 3 is a diagram of an example embodiment of a UE scanning receive beam for an SSB burst. Figure 2In the example beams shown, the network device 210 continuously forms beams B1, B2, B3, and B4. Each formation of a beam is called a "burst". The network device 210 can generate bursts for UE 150 to observe at intervals. Each time between intervals is called a "burst period", which can be longer than the duration of the burst.

[0073] In the example of 5G NR, each beam in a burst transmits information about the beam in what is called a signal synchronization block (SSB). The network device 210, which may be a gNodeB or a portion thereof, transmits an SSB in each beam in the burst. In some examples, the network device 210 may operate using one SSB (single beam operation) or using multiple SSBs (multi-beam operation). In an embodiment, the UE 150 may receive an SSB burst for each of its receive beams. Figure 2 In the example of four receive beams R1, R2, R3 and R4 shown in FIG. Figure 3 As shown, four intervals are required to receive a burst of all four receive beams. In some examples, UE 150 may operate using a single beam (e.g., an omni-directional beam). The SSBs of an SS burst may be provided by one or more (co-located or non-co-located) TRPs (transmit-receive points). The duration between bursts is referred to as a "burst period". In a 5G NR network, SSB bursts may last 5 ms each, and a burst period may have a default duration of 20 ms.

[0074] In the example of 5G NR, each SSB includes system information (SI) in the form of a master information block (MIB) and multiple system information blocks (SIBs). SI is divided into minimum SI and other SI. Minimum SI includes basic information that can be used for access network nodes and information for obtaining any other SI. Minimum SI includes MIB, which contains cell barring status information and physical layer information of the cell, which is used to receive additional system information (e.g., CORESET#0 configuration). MIB is broadcast periodically on the broadcast channel (BCH). Minimum SI also includes system information block 1 (SIB1), which defines the scheduling of other system information blocks and contains information for access network nodes. SIB1 can also be called residual minimum SI (RMSI) and is broadcast periodically on the downlink shared channel (DL-SCH).

[0075] Also refer to Figure 2In an example of the fifth generation new radio (5G NR) defined by the third generation partnership project (3GPP), a unified transmission configuration indicator (TCI) framework is used for beam configuration and / or indication. For example, the network device 210 may configure the UE 150 with a set of TCI states. Each TCI state may indicate at least a certain beam direction or a group of beam directions, which may correspond to a certain reference signal. In an example, the TCI state may be a TCI state for DL ​​for downlink (DL) communication from the network device 210 to the UE 150. In other examples, the TCI state may be a TCI state for UL for uplink (UL) communication from the UE 150 to the network device 210. In another example, the TCI state may be a joint TCI state for UL and DL communication between the network device 210 and the UE 150. The network device 210 may "activate" a UE having at least a subset of the configured TCI states. As used herein, "activating" a TCI state means that the UE 150 may monitor a signal, such as a reference signal, sent by the network device 210 corresponding to the TCI state. In an example, activation of a TCI state may mean that the UE is configured to monitor at least one reference signal associated with an activated TCI state, the activated TCI state being used, for example, for time / frequency tracking and / or path loss measurement. In an example, activation may mean that the UE 150 is expected to track at least one reference signal corresponding to the activated TCI state. In some examples, the network device 210 may activate one or more TCI states of the configured TCI states in the set and exclude one or more TCI states of the other configured TCI states in the set. Additionally, in order to communicate with the UE 150, the network device 210 may select one of the activated TCI states and "indicate" the selected TCI state to the UE 150. As used herein, "indicating" a TCI state means that the UE 150 may be configured to communicate with the network device 210 using a beam corresponding to the indicated TCI state (identified by a downlink reference signal). In various examples, UE 150 may be prepared to receive an indication of at least one of the activated TCI states and to communicate with network device 210 using the indicated TCI state within a specified time limit.

[0076] Figure 2 and Figure 3 The examples are merely illustrative. In embodiments, the number and direction of network node beams and the number and direction of UE beams may vary and may be related to Figure 2 and Figure 3 are different from those shown in .

[0077] As described above, the UE may travel from one area to another, and therefore a cell switching or mobility procedure (e.g., layer 3 handover or LTM) may be important to support continued communication of the UE with the network. In addition, when the UE moves from one cell coverage to another, a more efficient cell switching procedure (such as LTM) may be beneficial to avoid or at least reduce interruption of UE service.

[0078] Figure 4 is a diagram of an example embodiment of an LTM scenario. 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 be substantially similar to Figure 1 The network device 420 may be substantially similar to Figure 1 The network device 420 that actively or currently serves the UE 410 may be referred to as a serving cell. When the UE 410 moves toward the edge of the cell or area 402 served (or covered) by the network device 420, a cell switching procedure may be performed to switch the UE 410 to a neighboring cell served by, for example, another network device 430, 440. Figure 4 In the example shown, 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, area 402, area 404, and area 406 may partially overlap, as shown. In other examples, area 402, area 404, and area 406 may be non-overlapping. 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.

[0079] The term Layer 1 / Layer 2 Triggered Mobility (LTM) may 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 may be used interchangeably. An L1 / L2 signal, message or command sent by a network node to trigger a cell switch at a UE is referred to as a "cell switch command". In LTM, the decision about cell switching is based on L1 measurements and is made in the MAC layer in a distributed unit (DU). The cell switch command includes a MAC control element (MAC CE). The cell that is the target of the cell switch command may be referred to herein as a target cell. The mechanisms of LTM below will refer to Figure 7 is discussed more fully.

[0080] According to one aspect of the present disclosure, the network device 420 (serving cell) may activate the UE 410 with the TCI state for the candidate cell, and may optionally indicate the activated TCI state that can be used by the UE 410 in the case of a cell switch. In this regard, the network device 420 may 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 the UE 410, the serving cell network device 420 may send a cell switch command to the UE 410 via lower layer signaling (e.g., L1 / L2 signaling). The cell switch command may indicate a selected one of the one or more candidate cells as a target cell for the cell switch. In response to receiving the cell switch command, the UE 410 may switch to communicate with the target cell by applying at least one of the corresponding one or more activated TCI states.

[0081] Figure 4 The example is merely illustrative. In an embodiment, the number of candidate cells and the number of activated TCI states (or beams) may vary and may be related to Figure 4 are different from those shown in .

[0082] The process for the UE to establish communication with the target cell is called a random access process. The random access process can be used for initial access, inactive small data transmission and transition from RRC_Inactive to RRC_Connected, as well as beam failure recovery, connection reestablishment, handover and cell addition and other processes that will be recognized by those skilled in the art.

[0083] Two types of random access procedures include contention-based random access (CBRA) and contention-free random access (CFRA). Figure 5 5 is a diagram of an example of a contention based random access (CBRA) procedure. In the example shown, the signal includes a random access preamble (MSG1) sent by a UE 550 to a network node 510 (e.g., a gNodeB or a portion thereof), a random access response (MSG2) sent from the network node 510 to the UE 550, a scheduled transmission (MSG3) sent from the UE 550 to the network node 510, and a contention resolution (MSG4) sent from the network node 510 to the UE 550.

[0084] For MSG1, UE 550 performs the following operations based on a signal synchronization block (SSB) (such as the one described above in conjunction with Figure 3The UE 550 selects an available random access preamble using the information element in the SSB described in (described in (a)). The UE 550 sends the random access preamble (MSG1) to the network node 510 using a specific time and frequency resource called a random access opportunity (RO). The UE 550 also provides the network with an identity called a random access radio network temporary identity (RA-RNTI) so that the network can address it in the next step.

[0085] For MSG2, the network node 110 detects the preamble, calculates various quantities, and sends a physical uplink shared channel (PUSCH) uplink (UL) grant to the UE 550. This is called a random access response (RAR), which is sent as MSG2, which is addressed to the UE 550 with the associated RA-RNTI, and indicates to the UE 550 where in frequency and when in time MSG3 can be sent on the PUSCH.

[0086] For MSG3, in response to receiving MSG2 from network node 510, UE 550 uses the UL grant provided in RAR to send MSG3. Because 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 called a radio resource control (RRC) connection request message.

[0087] For MSG4, the network node 510 may send MSG4 to the UE 550 for contention resolution. Contention resolution may be operated in a manner specified by 3GPP for 5G NR. After the random access procedure, assuming that contention resolution is resolved favorably, the UE 550 becomes connected to the network node 510. After the connection is established, various procedures will be handled by the gNB-CU depending on the CU-DU split. Those skilled in the art will understand other aspects of contention-based random access (CBRA).

[0088] Another type of random access procedure is contention-free random access (CFRA) (not shown). In CFRA (not shown), the network node 510 sends an assigned random access preamble to the UE 550. The UE 550 receives the assigned random access preamble and sends the random access preamble as MSG1 to the network node 510 in a random access request. Then, MSG2 and MSG3 are similar to those described in conjunction with CBRA. Based on the use of the assigned random access preamble, no conflicts need to be resolved in CFRA. Those skilled in the art will understand other aspects of contention-free random access (CFRA).

[0089] When a UE moves from the coverage area of ​​one cell to another, a serving cell change is performed at some point. Conventional serving cell changes can be triggered by Layer 3 (L3) measurements (RRC measurement reports from the UE) and are accomplished by downlink RRC signaling (i.e., RRC reconfiguration messages with synchronization for changes of the primary cell (PCell) and primary secondary cell (PSCell)) and the release and addition of secondary cells (Scells) when applicable. All cases involve a complete L2 (and L1) reset, which may result in longer latency, greater overhead, and longer interruption time than beam switching mobility. By leveraging L1 / L2 mobility enhancements to implement serving cell changes via L1 / L2 signaling, latency, overhead, and interruption time can be reduced.

[0090] Figure 6 is a diagram of an example embodiment 600 of signals and operations between a UE, a central unit (CU), a source distributed unit (DU), and a target DU related to LTM according to an illustrated aspect of the present disclosure. It is intended and should be understood that other types of cell switching procedures (e.g., layer 3 handover) are within the scope of the present disclosure. The following paragraphs will describe various signals and operations. It should be understood that the described signals may have associated operations, and the described operations may have associated signals.

[0091] Reference now Figure 6 , example signals and operations for LTM and random access procedures for the inter-DU cell switching process are shown. This inter-DU scenario is illustrative, and aspects of the present disclosure may also be applied to intra-DU scenarios. In the case where the source DU and the 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, and the target CU may communicate via the Xn interface. As described above, the terms "send to...", "receive from...", and "cooperate with..." (and variations thereof) include communications that may or may not involve communications through one or more intermediate devices or nodes. Any description thereof that is intended to refer to a DU should also be deemed as if the description refers to a network node that supports at least one of the DU design functions or layer 2 protocols of a radio access network (RAN). Any description thereof that is intended to refer to a CU should also be deemed as if the description refers to a network node that supports at least one of the CU design functions or layer 3 protocols of a radio access network (RAN).

[0092] The following paragraphs describe various signals and operations. It should be understood that the described signals may have associated operations, and the described operations may have associated signals. Therefore, the described signals may also be operations, and the described operations may also be signals.

[0093] Prior to operation 601, the UE has established a connection with a DU supporting a serving cell (ie, a source DU), which serves the UE and has established a (logical) connection with a CU supporting the DU.

[0094] 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 the L3 measurement report, which may include, for example, an average measurement sample of a reference signal of a 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 the L3 measurement report to the CU, and the CU receives the L3 measurement report from the source DU. At operation 603, the CU performs a handover (HO) decision / target cell preparation decision based on the L3 measurement report regarding whether a handover should be prepared. For the illustrated embodiment, the CU decides that a handover should be prepared.

[0095] At operation 604, the CU sends a UE context establishment request to the target DU to prepare the target DU for switching 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 a UE context establishment response from the target DU. Although one target DU is shown, if there are multiple candidate cells, there may be more than one target DU. The operations at 604 and 605 can be used for each target DU and multiple candidate cells. The following description will mention the candidate cell to indicate that there may be one candidate cell or multiple candidate cells, and where appropriate, the target DU supporting the candidate cell will be mentioned. If the target DU and the source DU are supported by different Cus, the Cus can communicate using the Xn interface. For convenience, only one CU (the CU supporting the source DU) is shown, but it is intended that the technology disclosed in this disclosure is also applicable to multi-CU situations.

[0096] At operation 606, if necessary, the CU sends a UE context modification request to the source DU for modification of the UE context in the source DU, and for supply of 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.

[0097] At operations 604-607, the CU, the target DU, and the source DU may coordinate with each other regarding timing advance acquisition and configuration for the candidate cell. Timing advance refers to information used by the UE to adjust its uplink transmission to the network node to arrive at the network node aligned with the receive time window. This information may be referred to as a timing advance value or TA value in this article, and the process of obtaining a timing advance value may be referred to as timing advance acquisition, TA acquisition, obtaining timing advance, or obtaining TA (or its variants) in this article. As described above, the term "acquisition" (and its variants) includes acquiring in a first instance or reacquiring after the first instance. In an embodiment, the source DU and the target DU may coordinate (via the CU) a method for the UE to acquire the TA. In an embodiment, the UE may acquire a separate TA value for each candidate cell.

[0098] In an embodiment, the TA may be acquired based on a random access (RA) procedure (CFRA or CBRA), such as but not limited to a physical downlink control channel (PDCCH) ordered RA procedure, a UE-triggered RA procedure, and / or an upper layer-triggered RA procedure from a network node (except for an L3 handover command), etc. In an embodiment, the TA may be acquired based on a non-RA procedure method, such as but not limited to a sounding reference signal (SRS)-based TA acquisition, a timing difference-based mechanism (such as those in LTE), and / or a UE-based TA measurement, etc. Such RA-based and non-RA-based methods for TA acquisition are within the scope of the present disclosure.

[0099] At operation 608, the CU creates an RRC reconfiguration message including measurement configuration for L1 cell change, configuration of prepared cells, and TA acquisition configuration and trigger for candidate cells. In an embodiment, if CU participation is required later (in the execution phase), the RRC reconfiguration message may include the TA configuration. The TA configuration may, for example, specify a method for the UE to acquire the TA. In an embodiment, a TA acquisition method may be configured / triggered based on L3 measurements by the CU (coordinated with the source DU).

[0100] At signal 609, the CU sends an RRC reconfiguration message to the source DU using downlink (DL) RRC messaging, and the source DU receives the RRC reconfiguration message from the CU. As described above, the RRC reconfiguration message may include the above-mentioned TA configuration and activated or indicated TCI state information and cell switching 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 is reconfigured according to 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 messaging, 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 an embodiment, the signal and operations 609-612 may be described as part of a logical connection between the UE and the CU, so that the CU transmits an RRC message to the UE and the UE receives an RRC message from the CU.

[0101] In an embodiment, the above signals and operations 601-612 may be referred to as a preparation phase. Following the preparation phase is an execution phase.

[0102] In the execution phase, the UE provides periodic L1 measurement reports based on its configuration. Those skilled in the art will understand L1 measurements. L1 measurements can measure the signal power of a list of reference signals configured by the network. For example, L1 measurements can measure the signal power of reference signals corresponding to SSBs of 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 measurement L1 report can be an L3 measurement.

[0103] At operation 614, the source DU decides whether to trigger the UE to acquire a TA for the candidate cell set (ie, the candidate cells for handover configured by the CU at operation 608) based on the received L1 measurement report.

[0104] 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 at 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 physical downlink control channel (PDCCH) ordered RA procedure, a UE-triggered RA procedure, and / or an upper layer-triggered RA procedure from a network node (except for an L3 handover command), etc. In an embodiment, 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 timing difference-based mechanism (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 the present disclosure. After operation 615, if the TA acquisition procedure is successful, the UE may have a TA value for the candidate cell before the cell switch is triggered. If the TA acquisition procedure is unsuccessful, the UE will not have a TA value for the candidate cell.

[0105] At operation 616, the UE sends a random access preamble message to the target DU so that the target DU can estimate the TA between the UE and the target DU. When 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 to send to the UE, and the UE receives the random access response message from the source DU.

[0106] At operation 618, the UE continues the L1 measurement report and periodically sends the L1 measurement report to the source DU, and the source DU receives the periodic L1 measurement report from the UE.

[0107] In an embodiment, the signals and operations 613-618 may be collectively referred to as an execution phase. After the execution phase, in some example embodiments, several optional phases may be executed. The first option occurring after operation 618 may be executed at operations 619-624, and the second option occurring after operation 618 may be executed at operations 625-628.

[0108] For example, in the first optional phase operation 619 (option-1), the previous TCI activation occurs. For example, at operation 620, the source DU selects a potential target cell and its beam for which the previous TCI state is activated. 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 for LTM command.

[0109] At operation 622, the UE tracks the associated QCL RS and acquires downlink time / frequency synchronization. At operation 623, the source DU determines the target cell to which the UE is to be handed over. After the determination, at operation 624, the source DU sends a MAC CE triggered cell change message including the TA and TCI status indication of the target cell to the UE, and the UE receives the MAC CE triggered cell change message.

[0110] In the second optional phase operation 625 (option-2), simultaneous TCI activation and indication occurs. For example, at operation 626, the source DU determines the target cell and beam to which the UE is to be handed over. After the determination, at operation 627, the source DU sends a MAC CE triggered cell change message including the TA of the target cell, TCI state activation and TCI state indication to the UE, and the UE receives the MAC CE triggered cell change message. At operation 628, the UE tracks the associated QCL RS and acquires downlink time / frequency synchronization.

[0111] Upon completion of option-1 (ie, operations 619-624) or option-2 (ie, operations 625-628), the UE performs a random access procedure at operation 629, which will be understood by those skilled in the art.

[0112] At operation 630, in order to initiate communication with the target DU, the UE sends an RRC reconfiguration completion message to the target DU using the uplink (UL) resources that have been configured, and the target DU receives the RRC reconfiguration completion message from the UE. At step 631, the target DU sends an RRC reconfiguration completion message to the CU using UL RRC messaging to forward the RRC reconfiguration completion message, and the CU receives the RRC reconfiguration completion 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 step 633, the source DU sends a UE context release completion message to the CU, and the CU receives the UE context release completion message from the source DU. Then, the CU then performs a path switch to the target DU as a new DU supporting the serving cell.

[0113] Figure 6 The signals and operations are merely illustrative, and variations are contemplated within the scope of the present disclosure. For example, the signals and operations may assume one TA value per physical cell ID (PCI). In an embodiment, to cover multiple TRP (multiple transmit-receive point) scenarios, the UE may be configured and required to acquire multiple TAs for the PCI, such as different TA values ​​for different TCI state sets. In an embodiment, the signals and operations may include Figure 6 Other signals and operations not shown in the embodiment. In an embodiment, the signals and operations may not include Figure 6 In an embodiment, the signals and operations may be in the same Figure 6 Different orders are shown to be implemented. Such and other embodiments are considered within the scope of the present disclosure.

[0114] In some examples, transitioning a TCI state from an active TCI state to add another TCI state may cause delays. Figure 7 is a diagram of example TCI state transition delays for TCI state additions on the active TCI state list.

[0115] like Figure 7 As shown, the delay may 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 needs to synchronize with the corresponding SSB, which is why the delay involves T first-SSB and T SSB-proc , which is the time of transmission and SSB processing delay of the first SSB to the target TCI state after the MAC CE command of SSB with QCL-TypeA or QCL-TypeC. The SSB periodicity can be different in different configurations (e.g., 160ms). Therefore, the first SSB with the correct QCL relationship to the target TCI state can occur up to 160ms 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 FIG. 1 , if the target TCI state is already on the active TCI state list, then T 第一SSB and T SSB-proc Can be omitted in the delay.

[0116] Therefore, in order to reduce the above delay, in the case of LTM, a beam indication (TCI state) associated with the target cell may be provided as part of the cell switch command that the UE will use to communicate with the target cell. In order to provide a TCI state indication, early activation of such a TCI state for the UE may be performed to acquire time / frequency synchronization in advance (when connected to the source cell), which may reduce handover interruptions. In various embodiments, early activation of such a TCI state may be performed for the UE to start acquiring time / frequency synchronization after receiving a cell switch command or after connecting to a new target cell. In one example, connecting to a new target cell may mean that the UE has sent an RRC message to the target cell (e.g., RRC reconfiguration is complete). This may reduce handover interruptions or increase throughput when entering a new cell (i.e., the UE may be scheduled by higher order modulation / or using higher gain beams, etc.). Each candidate target cell may be prepared by a set of TCI states given in an LTM configuration that is given outside the current serving cell or cell configuration.

[0117] Since one of the current serving cells (such as SCell, secondary cell) may also be selected as a candidate target cell for cell switching (e.g., as a target PCell), the TCI state for the candidate target cell may have been activated based on its serving cell configuration, and the TCI state activation for the cell switching using the LTM configuration for the current active serving cell may cause unnecessary activation delay (and / or activation signaling), and it may be desirable to minimize the activation delay and signaling overhead in such a scenario. In addition, the UE may include information about both the TCI state from the intra-cell activation pool and the TCI state of the LTM TCI state pool. In some example embodiments, the TCI state of the intra-cell pool may be considered to be a "first TCI state" of a "first TCI state pool", and the TCI state of the LTM TCI state pool may be considered to be a "second TCI state" of a "second TCI state pool". The TCI state pools are therefore inherently different configurations (e.g., may be configured separately) and may include independently configured (same or different) TCI state sets. The TCI state pool may refer to a list of TCI states that may be activated for beam indications of at least one of the activated TCI states (these are activated TCI states). The pool or list of TCI states may be configured using RRC signaling. The TCI state list (TCI state pool) may be a list of joint DL / UL TCI states (i.e., for both uplink and downlink communications). The TCI state list (TCI state pool) may be a list of separate DL or UL TCI states. The intra-cell activation pool may refer to a list of TCI states that may be activated for beam indications for intra-cell communications (e.g., for beam management). The LTM TCI state pool may refer to a list of TCI states that may be activated for beam indications for LTM cell switching (e.g., for beam indications prior to cell switching or beam indications in a cell switching command or beam indications after a cell switching command). For the TCI state pool, if only one TCI state (single TCI state) is activated, it is also the indicated TCI state. In some cases, if the TCI state is indicated as not activated, the indicated TCI state may also be changed to an activated TCI state.

[0118] Figure 8 is a diagram of an example embodiment of signals and operations 800 in an LTM TCI activation procedure among a UE, a CU, a source cell, and a candidate cell in accordance with one illustrated aspect of the present disclosure.

[0119] The following paragraphs will describe various signals and operations. It should be understood that the described signals may have associated operations, and the described operations may have associated signals. Therefore, the described signals may also involve operations, and the described operations may also involve signals. In addition, in some example embodiments, the terms source cell and candidate cell may be used interchangeably with the terms "source DU" and "candidate DU". In addition, as used herein, PDCCH may refer to a physical downlink control channel, PDSCH may refer to a physical downlink shared channel, PUSCH may refer to a physical uplink shared channel, PUCCH may refer to a physical uplink control channel, DMRS may refer to a demodulation reference signal, and TRS may refer to a tracking reference signal.

[0120] At operation 801, the UE establishes a connection with a source cell C0 (e.g., a serving cell supporting a serving cell and a source DU that has established a (logical) connection with a CU supporting a DU). The UE includes a capability for determining that TCI associated with a TCI state pool is activated based on 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 embodiments, the UE may indicate its activated capability to support TCI states of one TCI state pool based on an activated TCI state or state of another TCI state pool.

[0121] At operation 802, the measurement report is shared between the UE, the source cell C0, the candidate cell C1, and the CU. In some example embodiments, the sharing may include similar to the above in Figure 6 The operations 601 (L3 measurement report message) and 602 (UL RRC message transmission) described in FIG.

[0122] Therefore, based on the measurement report (e.g., L3 measurement report), at operation 803, LTM preparation is performed by the CU, and the LTM configuration including the TCI state of the candidate cell is provided to the UE. As described above, the UE also includes the TCI state configured under the current serving cell configuration for intra-cell / inter-cell beam management (BM). This may be referred to as a BM TCI pool. The UE is also configured such that for BM TCI activation, activation is allowed / configured / enabled based on an activated TCI state of another TCI state pool (e.g., an LTM TCI state pool). Alternatively or additionally, the UE is configured such that for LTM TCI activation, activation is allowed / configured / enabled based on an activated TCI state of another TCI state pool (e.g., a BM TCI state pool).

[0123] Different types of configuration options (eg, based on TA acquisition status, L1 measurement quality, or a set of candidate cells that are allowed to be indicated) may be utilized.

[0124] For example, the UE may be configured (e.g., in RRC) whether TCI state activation from one TCI state pool of configured TCI states may be based on an activated TCI state of another TCI state pool. For example, for LTM, in the LTM preparation phase described below, the UE may be configured in an RRC (reconfiguration) message whether TCI activation for LTM candidate cells may be based on an activated TCI state of another TCI state pool (configured for intra-cell / inter-cell BM of the current serving cell).

[0125] In various embodiments, the UE may be configured such that the UE may determine activation of one or more TCI states based on activated TCI states of another TCI state pool (eg, a TCI state pool specific to a cell or a set of cells).

[0126] In various embodiments, the MAC-CE activation command may contain an indication common to all included TCI states in the MAC-CE or a separate indication for each included TCI state, whether the activation of one or more TCI states of one TCI state pool may be used to activate one or more TCI states of another TCI state pool. For example, the MAC-CE activation command may contain an indication that the activation of one or more TCI states of the LTM TCI state pool may be used to activate one or more TCI states of the intra-cell / inter-cell BM TCI state pool. Or vice versa: the MAC-CE activation command may contain an indication that the activation of one or more TCI states of the intra-cell / inter-cell BM TCI state pool may be used to activate one or more TCI states of the LTM TCI state pool.

[0127] In various embodiments, the message providing the cell switch command (eg, MAC-CE) may include an indication of whether the UE may consider the activated TCI state of one TCI state pool based on the activation of the TCI state of another TCI pool.

[0128] In various embodiments, in the case of simultaneous activation and indication via a cell switch command, the MAC-CE cell switch command may include an indication common to all included TCI states of a TCI state pool in the MAC-CE or a separate indication for each included TCI state.

[0129] In various embodiments, the UE may be configured to consider activation based on a previous activation of another TCI state pool for a candidate cell, or based on a downlink RS for which a TA is available or a TA acquisition procedure has been performed. The TA acquisition procedure may also include sending a PRACH transmission to the candidate cell based at least on a PDCCH order from the network.

[0130] In various embodiments, the UE may be configured to consider activation (of one or more TCI states of a TCI state pool) based on the (previous) activation of another TCI state pool for candidate cells or downlink RSs based on L1 measurements. As an example, the DL RS for L1 measurements may be configured as a DL RS in a TCI state (i.e., the TCI state contains / includes a DL RS, which is also a DL RS for L1 measurements). As an example, for a DL RS, the L1 measurement is higher than a certain quality (configured threshold), or the L1 measurement after the last activation (associated with the first TCI state pool) has not been changed by more than a certain threshold. As an example, the threshold may be expressed in dB (e.g., 3dB, 6dB, etc.). The threshold may be configured by the network (e.g., via RRC signaling). In one example, the L1 measurement may need to be a reported measurement to be considered activated (e.g., reported at least once).

[0131] In various embodiments, the configuration may be configured (eg, via RRC signaling) by each TCI state in a TCI state pool or a set of TCI states in a TCI state pool, regardless of whether activation is applied.

[0132] In some example embodiments, the source cell may indicate to the target cell in handover related signaling which TCI states / QCL sources are considered to be activated from the UE perspective.

[0133] In some example embodiments, the source cell may indicate to the target cell in handover related signaling whether the TCI state / QCL source of one TCI state pool is considered to have been activated based on the activation of another TCI state pool from the UE perspective.

[0134] At operation 804, the source cell sends a MAC-CE activation for intra-cell / inter-cell BM message to the UE, and the UE receives the MAC-CE activation message for intra-cell / inter-cell BM (i.e., activation of TCI state for intra-cell / serving cell beam management). The MAC-CE activation for intra-cell / inter-cell BM message includes one TCI state from the serving cell TCI state pool being activated (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 synchronization is acquired at operation 806, the TCI state (e.g., TCI state x) can be used (or can be used for beam indication) after the activation transition delay.

[0135] At operations 807-808, the UE continues the L1 measurement report and periodically sends the L1 measurement report to the source cell, and the source cell receives the periodic L1 measurement report from the UE.

[0136] Based on the received L1 measurement, at operation 809, the source cell may decide to activate a TCI state (e.g., TCI state y) associated with a candidate cell (e.g., candidate cell C1). TCI state y may be selected from an LTM TCI state list that gives an LTM TCI state pool for candidate cell C1. The source cell sends a MAC-CE activation for the LTM command to the UE, and the UE receives a MAC-CE activation for the LTM command. The MAC-CE command may indicate to the UE to activate TCI state y.

[0137] Therefore, upon receiving a MAC-CE activation for one or more TCI states of the LTM TCI state pool from the serving cell (source cell), the UE can determine that at least one of the QCL source RSs of TCI state y (e.g., the second TCI state) is also a QCL source RS of TCI state x (e.g., the first TCI state), which has been activated, although belonging to a different TCI state pool, i.e., the intra-cell / inter-cell BM TCI state pool. That is, when the QCL reference signal of the first TCI state is the same as the QCL reference signal of the second TCI state, it can be considered that the QCL reference signal of the first TCI state is related / associated / shares a common attribute with the QCL reference signal of the second TCI state.

[0138] In one embodiment, upon receiving a MAC-CE activation for one or more (second) TCI states of the LTM TCI state pool from a serving cell (source cell), the UE may determine whether at least one of the LTM TCI states shares the same attribute (or is more generally related to) with one or more (first) TCI states of the intra-cell TCI state pool. If the UE determines that they share the same attribute (e.g., the same QCL source RS), the UE may determine that the one or more (second) TCI states are already active. Activation of one or more second TCI states may be performed upon determining whether the TCI states (first and second) share the same attribute (i.e., upon receiving an activation message for the second TCI state). In some examples, activation (and determining whether the TCI states share at least one same attribute) may be performed upon connection to a target cell. In one example, activation may be performed (and attributes determined) upon receiving a cell switch command for a target cell associated with one or more first TCI states.

[0139] That is, when the QCL reference signal of the first TCI state defines the same or exactly the same (signal) as the QCL reference signal of the second TCI state, the QCL reference signal of the first TCI state can be considered to be related / associated / share common properties with the QCL reference signal of the second TCI state.

[0140] In various embodiments, if the first TCI state (of the first pool and the second pool) shares a common characteristic, the TCI state activation delay can be reduced because the above-mentioned synchronization delay can be reduced or even eliminated. In one example, the first TCI state can be activated, which can make the UE determine the second TCI state to be activated if the first TCI state contributes at least one common attribute to the second TCI state or they are related. 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 is activated in a second message (e.g., an activation MAC CE associated with the second TCI state). If the first TCI state and the second TCI state share at least one common attribute or they are related, receiving the second message can enable the UE to determine that the second TCI state is activated without activation delay or with reduced activation delay. After the cell transition has been performed on the cell associated with the second TCI state, the activated (second) TCI can also be assumed to be a known TCI state / in the active TCI state list for beam indication. Known TCI state / in the active TCI state list may mean that at least the UE is able to receive downlink channels (PDSCH / PDCCH) with reduced delay. There may be one or more first TCI states and one or more second TCI states. The first TCI state may refer to the intra-cell / serving cell beam management TCI state. The second TCI state may refer to the LTM TCI state. In other words, the activation of the first TCI state may be used to determine the activation of the second TCI state when an activation message for the first TCI state is received (the first and second TCI states may have an activation delay of X milliseconds / time slots). Alternatively, the activation of the first TCI state may be used to determine the activation of the second TCI state when a second activation message for the second TCI state is received (where the activation of the first TCI state has been provided in the first message), so that the UE does not apply an activation / conversion delay (e.g., X milliseconds / time slot) or applies a reduced activation / conversion delay. Similarly, the first TCI state may be determined to be activated based on the second TCI state as described herein.

[0141] In some examples, if the TCI state (or states) is known (based on activation), it can be assumed to be ready for reception and / or transmission of at least a downlink or uplink channel, regardless of the (additional) delay component based on the DL RS measurement associated with the TCI state (e.g., SSB). Figure 7 In an example shown in FIG. 1 , if the target TCI state is already on the active TCI state list, then T first-SSB and T SSB-proc Can be omitted in the delay.

[0142] In various embodiments, when the QCL reference signal of the first TCI state shares the same one or more QCL properties (e.g., one or more of Doppler spread, Doppler shift, delay spread, or average delay) with the QCL reference signal of the second TCI state, the QCL reference signal of the first TCI state can be considered to be related / associated / share common properties with the QCL reference signal of the second TCI state.

[0143] In various embodiments, when the QCL reference signal of the first TCI state is QCLed with the QCL reference signal of the second TCI state by type D (spatial domain relationship, e.g., same beam), the QCL reference signal of the first TCI state may be considered to be related / associated with the QCL reference signal of the second TCI state. For example, the QCL reference for the first TCI state may be TRS, and the QCL reference signal associated with the second TCI state is SSB, where TRS and SSB are QCLed by QCL type D.

[0144] In various embodiments, if the QCL source RS of a first TCI state (a TCI state may include a TRS-CSI-RS) and a second TCI state share the same QCL source (SSB or CSI-RS), all TCI states with a target RS (such as one or more TCIs including a TRS and having the same source RS) are considered to be activated TCI states in all TCI state pools or at least in multiple TCI state pools.

[0145] In various embodiments, if the QCL source RS of the first TCI state (TCI state may include TRS-CSI-RS or SSB) and the QCL source RS of the second TCI state (TCI state may include TRS-CSI-RS or SSB) are the same signal, the UE may determine that the TCI states share the same attribute. The same attribute may refer to the same QCL source RS (SSB or CSI-RS).

[0146] In various embodiments, if the QCL source of the QCL source RS of the first TCI state (the QCL source of the QCL source RS may be, for example, SSB) and the QCL source of the QCL source RS of the second TCI state (the QCL source of the QCL source RS may be, for example, SSB) are the same signal, the UE may determine that the TCI states share the same attributes or that they are related. The same attributes may refer to the QCL source of the same QCL source RS (SSB or CSI-RS). In other words, the TCI state may include a QCL source RS (e.g., TRS-CSI-RS) having another QCL source RS such as SSB (main QCL source). As an example of a QCL relationship (or QCL chain), it may be PDCCH DMRS->TRS-CSI-RS->SSB. The QCL source RS of the TCI state may be a source RS for a target signal such as PDCCH / PDSCH / PUSCH / PUCCH DMRS.

[0147] 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 cell switching decision for the candidate cell C1 using TCI state y. Once the decision is made, at operation 813, the source cell sends an LTM conversion command with a TCI state indication including TCI state y to the UE, and the UE receives an LTM conversion command with a TCI state indication including TCI state y. If there is no previous TCI activation for TCI state y of the LTM, simultaneous activation and indication as described above may be performed.

[0148] At operation 814, in order to initiate communication with the candidate cell, the UE sends an RRC reconfiguration complete message to the target cell using the uplink (UL) resources that have been configured, and the candidate cell receives the RRC reconfiguration complete message from the UE. At step 815, the candidate cell sends an RRC reconfiguration complete message to the CU using UL RRC messaging to forward the RRC reconfiguration complete message, and the CU receives the RRC reconfiguration complete message from the candidate cell. The CU can then perform a path switch to the candidate cell as a serving cell.

[0149] Figure 8 The signals and operations are merely illustrative, and variations are contemplated within the scope of the present disclosure. In an embodiment, the signals and operations may include Figure 8 Other signals and operations not shown in the embodiment. In an embodiment, the signals and operations may not include Figure 8 In an embodiment, the signals and operations may be in the same Figure 8 Such and other embodiments are contemplated within the scope of the present disclosure.

[0150] Reference now Fig. 9 , a block diagram of example components of a UE or network device is shown. The device includes an electronic storage 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 can 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, such as RAM, or a non-volatile type of memory, such as 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, for example Figure 6 and Figure 8 operation.

[0151] Electronic storage 910 may be and include any type of electronic storage used to store data, such as a hard drive, a solid state drive, and / or an optical disk, among other types of electronic storage. Electronic storage 910 stores processor-readable instructions for causing the device to perform its operations and store data associated with such operations, such as storing data related to the 5G NR standard, etc. Network interface 240 may implement wireless network technologies such as 5G NR and / or other wireless network technologies.

[0152] Fig. 9 The components shown in the embodiment are merely examples, and those skilled in the art will appreciate that the device includes other components not shown, and may include multiples of any of the components shown. Such and other embodiments are contemplated within the scope of the present disclosure.

[0153] Other embodiments of the present disclosure include the following examples.

[0154] Example 1.1 A method for communication, comprising:

[0155] Receiving, by a user equipment (UE) connected to a first cell, a first transmission configuration indicator (TCI) state pool for a second cell, and activation of a second TCI state for a second TCI state pool for the second cell;

[0156] Determining, by the UE, that a quasi-co-site (QCL) reference signal of a first activated TCI state shares one or more attributes with a QCL reference signal of a second TCI state;

[0157] activating, by the UE, a second TCI state of the second cell based on the determination;

[0158] The UE performs a cell switch to the second cell using the activated second TCI state of the second cell.

[0159] Example 1.2 The method according to Example 1.1, wherein the UE maintains an activated second TCI state of the second cell when switching to the second cell.

[0160] Example 1.3 The method of Example 1.1, wherein after switching to the second cell, activation of a second TCI state of the second cell is determined.

[0161] Example 1.4 A method according to any one of Examples 1.1-1.3, wherein a first activated TCI state of a first TCI state pool is associated with a beam management configuration for a second cell, and a second TCI state of a second TCI state pool is associated with a lower layer triggered mobility (LTM) configuration for the second cell.

[0162] Example 1.5 A method according to any one of Examples 1.1-1.3, wherein a first activated TCI state of a first TCI state pool is associated with a lower layer triggered mobility (LTM) configuration for a second cell, and a second TCI state of a second TCI state pool is associated with a beam management configuration for the second cell.

[0163] Example 1.6 A method according to any of Examples 1.1-1.5, wherein the second cell is configured as an LTM candidate cell.

[0164] Example 1.7 The method of Example 1.6, wherein the second cell is configured as a serving cell.

[0165] Example 1.8 A method as described in any of Examples 1.1-1.7, wherein determining that a first activated TCI state and a second TCI share one or more properties includes determining that a quasi-co-site (QCL) reference signal of the first activated TCI state is equal to a QCL reference signal of the second TCI state.

[0166] Example 1.9 A method according to any one of Examples 1.1-1.7, wherein determining that a first activated TCI state and a second TCI share one or more attributes includes determining that a quasi-co-site (QCL) reference signal of the first activated TCI state shares one or more attributes with a QCL reference signal of the second TCI state.

[0167] Example 1.10 The method of Example 1.9, wherein the one or more QCL properties include one or more of: Doppler spread, Doppler shift, delay spread, or average delay.

[0168] Example 1.11 The method of Example 1.9, wherein the QCL reference signal of the first activated TCI state that shares one or more attributes with the QCL reference signal of the second TCI state includes the QCL reference signal of the first activated TCI state, including the same QCL source reference signal (RS).

[0169] Example 1.12 A method according to any of Examples 1.1-1.11, wherein activation of a first TCI state for a first TCI state pool associated with a second cell and a second TCI state for a second TCI state pool associated with the second cell is included in a media intervention control (MAC) control element (CE) message.

[0170] Embodiment 2.1 A user equipment UE includes:

[0171] means for receiving, by a UE connected to a first cell, a first transmission configuration indicator (TCI) state for a first TCI state pool associated with a second cell and an activated second TCI state for a second TCI state pool associated with the second cell;

[0172] means for determining, by the UE, that the first activated TCI state and the second TCI state share one or more attributes;

[0173] means for activating, by the UE, a second TCI state for the second cell based on the determination; and

[0174] Means for performing, by the UE, a cell switch to the second cell using the activated second TCI state of the second cell.

[0175] Example 2.2. The UE of Example 2.1, wherein the UE comprises means for maintaining the activated second TCI state of the second cell upon transition to the second cell.

[0176] Example 2.3 The UE of Example 2.1, wherein activation of the second TCI state of the second cell is determined after transitioning to the second cell.

[0177] Example 2.4 is a UE according to any of Examples 2.1-2.3, wherein the first activated TCI state of the first TCI state pool is associated with the beam management configuration for the second cell, and the second TCI state of the second TCI state pool is associated with the lower layer triggered mobility (LTM) configuration for the second cell.

[0178] Example 2.5 A UE according to any of Examples 2.1-2.3, wherein a first activated TCI state of a first TCI state pool is associated with a lower layer triggered mobility (LTM) configuration for a second cell, and a second TCI state of a second TCI state pool is associated with a beam management configuration for the second cell.

[0179] Example 2.6 A UE according to any of Examples 2.1-2.5, wherein the second cell is configured as an LTM candidate cell.

[0180] Example 2.7 The UE of Example 2.6, wherein the second cell is configured as a serving cell.

[0181] Example 2.8 A UE according to any of Examples 2.1-2.7, wherein the determination that the first activated TCI state and the second TCI share one or more attributes includes determining that a quasi co-located (QCL) reference signal of the first activated TCI state is equal to a QCL reference signal of the second TCI state.

[0182] Example 2.9 is a UE according to any of Examples 2.1-2.7, wherein the determination that the first activated TCI state and the second TCI share one or more attributes includes determining that a quasi-co-site (QCL) reference signal of the first activated TCI state shares one or more attributes with the QCL reference signal of the second TCI state.

[0183] Example 2.10 The UE of Example 2.9, wherein the one or more QCL attributes include one or more of: Doppler spread, Doppler shift, delay spread, or average delay.

[0184] Example 2.11 The UE of Example 2.9, wherein the QCL reference signal of the first activated TCI state shares one or more attributes with the QCL reference signal of the second TCI state, including the QCL reference signal of the first activated TCI state, which includes the same QCL source reference signal (RS).

[0185] Example 2.12 A UE as described in any of Examples 2.1-2.11, wherein activation of a first TCI state for a first TCI state pool associated with a second cell and a second TCI state for a second TCI state pool associated with the second cell is included in a media intervention control (MAC) control element (CE) message.

[0186] Example 3.1 An apparatus for communication, comprising:

[0187] means for transmitting, by the first cell, to a user equipment (UE), a first message including at least a first activated transmission configuration indicator (TCI) state of a first TCI state pool associated with a second cell and a second TCI state of a second TCI state pool associated with the second cell based on the first activated TCI state and the second TCI state sharing one or more attributes;

[0188] means for performing beam management by the first cell using the first TCI state; and

[0189] A unit is configured to transmit, by a first cell to a user equipment, an instruction for a lower layer triggered mobility (LTM) cell switch to a second cell, the instruction comprising a second TCI state for the second cell.

[0190] Example 3.2 The apparatus of Example 3.1, wherein the LTM cell switch instruction comprises a command for an LTM cell switch to a second cell.

[0191] Example 3.3 An apparatus according to Example 3.1, wherein determining a first activated TCI state and a second TCI state that share one or more attributes includes: determining that a quasi-co-site (QCL) reference signal of the first activated TCI state is equivalent to a QCL reference signal of the second TCI state.

[0192] Example 3.4 is a device according to Example 3.1, wherein the determination that the first activated TCI state and the second TCI share one or more attributes includes: determining that a quasi-co-site (QCL) reference signal of the first activated TCI state shares one or more attributes with the QCL reference signal of the second TCI state.

[0193] Example 3.5 The apparatus of Example 3.4, wherein the one or more QCL properties include one or more of: Doppler spread, Doppler shift, delay spread, or average delay.

[0194] Example 3.6: The apparatus of Example 3.4, wherein the QCL reference signal of the first activated TCI state that shares one or more attributes with the QCL reference signal of the second TCI state includes the QCL reference signal of the first activated TCI state including the same QCL source reference signal (RS).

[0195] Example 3.7 An apparatus as described in any of Examples 3.1-3.6, wherein a first activated TCI state of a first TCI state pool is associated with a lower layer triggered mobility (LTM) configuration for a second cell, and a second TCI state of a second TCI state pool is associated with a beam management configuration for the second cell.

[0196] Example 3.8 An apparatus according to any of Examples 3.1-3.7, wherein the second cell is configured as an LTM candidate cell.

[0197] Example 3.9: The apparatus of any of Examples 3.1 to -3.8, wherein the second cell is configured as a serving cell.

[0198] Example 3.10: The apparatus of any of Examples 3.1 to -3.9, wherein the first message is a medium access control (MAC) control element (CE) message.

[0199] The embodiments and aspects disclosed herein are examples of the present disclosure and may be embodied in various forms. For example, although some embodiments herein are described as separate embodiments, each embodiment herein may be combined with one or more of the other embodiments herein. The specific structural and functional details disclosed herein should not be interpreted as restrictive, but as the basis of the claims, and as a representative basis for teaching those skilled in the art to adopt the present disclosure differently in virtually any appropriately detailed structure. Throughout the description of the drawings, the same reference numerals may refer to similar or identical elements.

[0200] For example, the above is a scenario when the UE receives an activated TCI activation command containing one or more first TCI state indexes associated with a first configured TCI state pool, after determining that at least one QCL source reference signal of a second TCI state of the second pool is associated with the QCL reference signals of one or more first activated TCI states of the first TCI state pool, one or more second TCI states associated with the second TCI pool are considered.

[0201] In some example embodiments, the first TCI state pool may be a TCI state pool associated with one of the current serving cells, and the second TCI state pool may be a TCI state pool configured for the LTM candidate cells.

[0202] In some example embodiments, the first TCI state pool may be a TCI state pool configured for LTM candidate cells, and the second configured TCI state pool may be a TCI state pool associated with one of the current serving cells.

[0203] In some example embodiments, if the UE is configured with one or more TCI state pools for a serving cell and another TCI state pool for LTM, then when a TCI state is activated for an LTM candidate cell, if the target TCI state is on the active TCI state list belonging to any of the configured TCI state pools, then synchronization with an SSB having a QCL relationship with the target TCI state may not be considered in the TCI state activation or LTM cell transition delay.

[0204] The phrases "in one aspect," "in aspects," "in various aspects," "in some aspects," or "in other aspects" may each refer to one or more of the same or different aspects according to the present disclosure. The phrase "plurality" may refer to two or more.

[0205] The phrases "in one embodiment," "in an embodiment," "in various embodiments," "in some embodiments," or "in other embodiments" may each refer to one or more of the same or different embodiments according to the present disclosure. Phrases of the form "A or B" mean "(A), (B), or (A and B)." Phrases of the form "at least one of A, B, or C" mean "(A); (B); (C); (A and B); (A and C); (B and C); or (A, B, and C)."

[0206] Any method, program, algorithm or code described herein can be converted into programming language or computer program or expressed in programming language or computer program. As used herein, the terms "programming language" and "computer program" each include any language for computer specified instructions, and include (but not limited to) the following languages ​​and derivatives thereof: assembly, Basic, Batch file, BCPL, C, C#, C++, Delphi, Fortran, Java, JavaScript, machine code, operating system command language, Pascal, Perl, PL1, Python, scripting language, Visual Basic, the metalanguage of its own specified program, and all first, second, third, fourth, fifth or other generated computer languages. Also include databases and other data patterns and any other metalanguage. There is no difference between the languages ​​of the methods of being interpreted, compiled or using compilation and interpretation. There is no difference between the compiled version and the source version of the program. Therefore, the reference to the program is a reference to any and all such statements, wherein the programming language can exist in more than one state (such as source, compilation, object or link). The reference to the program can cover the intention of actual instructions and / or these instructions.

[0207] Although various aspects of the disclosure are shown in the accompanying drawings, it is not intended that the disclosure be limited thereto, as it is intended that the disclosure be as broad as the art will allow, and the specification is to be read similarly. Therefore, the above description should not be construed as limiting, but merely as an illustration of particular aspects. Other modifications within the scope and spirit of the appended claims will occur to those skilled in the art.

Claims

1. A method for communication, comprising: receiving, by a user equipment (UE) connected to a first cell, activation of a first transmission configuration indicator (TCI) state pool for a first configuration associated with a second cell, and also receiving configuration of a second TCI state of a second TCI state pool associated with the second cell; Determining, by the UE, that the first activated TCI state and the second TCI state share one or more attributes; Based on the determination, activating, by the UE, the second TCI state of the second cell; The UE performs a cell switch to the second cell, 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 activation for the first TCI state and before the cell switching, and maintains the activated second TCI state of the second cell after switching 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 switching to the second cell.

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

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

6. The method according to any one of claims 1 to 3, wherein the second cell is configured as an LTM candidate cell. The method according to claim 6 , wherein the second cell is configured as a serving cell.

8. The method of any one of claims 1 to 3, wherein the determination that the first activated TCI state and the second TCI share one or more attributes comprises determining that a quasi-co-site (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 3, wherein the determination that the first activated TCI state and the second TCI share one or more attributes comprises determining that a quasi-co-site (QCL) reference signal of the first activated TCI state shares one or more attributes with the QCL reference signal of the second TCI state.

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

11. The method according to claim 9, wherein: The QCL reference signal of the first activated TCI state shares one or more properties with the QCL reference signal of the second TCI state including: the QCL reference signal of the first activated TCI state includes the same QCL source reference signal (RS).

12. The method according to any one of claims 1 to 3, wherein the activation of the first TCI state of the first TCI state pool associated with the second cell and the second TCI state of 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 for communication, comprising: at least one processor; as well as at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least perform: Based on a first activated transmission configuration indicator (TCI) state and a second TCI state sharing one or more attributes, a first cell sends a first message to a user equipment (UE), wherein the first message includes at least the first activated TCI state of a first TCI state pool associated with a second cell, and also includes the second TCI state of a second TCI state pool associated with the second cell; The first cell performs beam management using the first TCI state; An instruction for lower layer triggered mobility (LTM) cell switching to the second cell is sent by the first cell to the user equipment, and the instruction includes the second TCI state for the second cell.

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

15. The apparatus of claim 13, wherein the determination that the first activated TCI state and the second TCI state share one or more attributes comprises determining that a quasi-co-located (QCL) reference signal of the first activated TCI state is equivalent to the QCL reference signal of the second TCI state.

16. The apparatus of claim 13, wherein the determination that the first activated TCI state and the second TCI share one or more attributes comprises determining that a quasi-co-located (QCL) reference signal of the first activated TCI state shares one or more attributes with the QCL reference signal of the second TCI state.

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

18. The apparatus of claim 16, wherein the QCL reference signal of the first activated TCI state shares one or more properties with the QCL reference signal of the second TCI state, including: the QCL reference signal of the first activated TCI state comprises the same QCL source reference signal (RS).

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

20. The apparatus according to any one of claims 13 to 18, wherein the second cell is configured as a LTM candidate cell. The apparatus according to claim 20 , wherein the second cell is configured as a serving cell.

22. The apparatus of any one of claims 13 to 18, wherein the first message is a Medium Access Control (MAC) Control Element (CE) message.

23. A user equipment (UE), comprising: at least one processor; as well as at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus to at least perform: receiving, by the user equipment (UE) connected to the first cell, activation of a first transmission configuration indicator (TCI) state for a first configured TCI state pool associated with a second cell, and also receiving configuration of a second TCI state for a second TCI state pool associated with the second cell; Determining, by the UE, that the first activated TCI state and the second TCI state share one or more attributes; Based on the determination, activating, by the UE, the second TCI state of the second cell; The UE performs a cell switch to the second cell, maintaining the activated second TCI state of the second cell.

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

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

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

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

28. The UE according to any one of claims 23 to 25, wherein the second cell is configured as an LTM candidate cell. The UE according to claim 28 , wherein the second cell is configured as a serving cell.

30. A UE as described in any one of claims 23 to 25, wherein the determination that the first activated TCI state and the second TCI share one or more attributes includes determining that a quasi-co-site (QCL) reference signal of the first activated TCI state is equivalent to the QCL reference signal of the second TCI state.

31. A UE as described in any one of claims 23 to 25, wherein the determination that the first activated TCI state and the second TCI share one or more attributes includes determining that a quasi-co-site (QCL) reference signal of the first activated TCI state shares one or more attributes with the QCL reference signal of the second TCI state.

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

33. The UE of claim 32, wherein the QCL reference signal of the first activated TCI state shares one or more properties with the QCL reference signal of the second TCI state, comprising: The QCL reference signals of the first activated TCI state include the same QCL source reference signal (RS).

34. The UE of any one of claims 23 to 25, wherein the activation of the first TCI state of the first TCI state pool associated with the second cell and the second TCI state of 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. When the instructions are executed by at least one processor of a device, the device performs at least one method, comprising: receiving, by a user equipment (UE) connected to a first cell, activation of a first transmission configuration indicator (TCI) state pool for a first configuration associated with a second cell, and also receiving configuration of a second TCI state of a second TCI state pool associated with the second cell; Determining, by the UE, that the first activated TCI state and the second TCI state share one or more attributes; Based on the determination, activating, by the UE, the second TCI state of the second cell; The UE performs a cell switch to the second cell, maintaining the activated second TCI state of the second cell.

36. A method for communication, comprising: Based on a first activated transmission configuration indicator (TCI) state and a second TCI state sharing one or more attributes, a first cell sends a first message to a user equipment (UE), wherein the first message includes at least the first activated TCI state of a first TCI state pool associated with a second cell, and also includes the second TCI state of a second TCI state pool associated with the second cell; The first cell performs beam management using the first TCI state; An instruction for lower layer triggered mobility (LTM) cell switching to the second cell is sent by the first cell to the user equipment, and the instruction includes the second TCI state for 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 comprising: Based on a first activated transmission configuration indicator (TCI) state and a second TCI state sharing one or more attributes, a first cell sends a first message to a user equipment (UE), wherein the first message includes at least the first activated TCI state of a first TCI state pool associated with a second cell, and also includes the second TCI state of a second TCI state pool associated with the second cell; The first cell performs beam management using the first TCI state; An instruction for lower layer triggered mobility (LTM) cell switching to the second cell is sent by the first cell to the user equipment, and the instruction includes the second TCI state for the second cell.

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