Managing transmission configuration indicator states for low-layer triggered mobility

Abstract

Methods and apparatus operate within a radio access network to facilitate fast serving cell change using a low layer triggered mobility (LTM) procedure that reduces latency and overhead relative to an L3 triggered cell handover procedure. The LTM is triggered by an L1 measurement report. Methods and apparatus according to various embodiments exchange LTM related configurations including an LTM identification (ID) and at least one LTM transmission configuration indicator (TCI) state configuration. The LTM TCI state configuration is associated with the LTM ID, or with a TCI state ID, or with a candidate cell ID.

Description

[0001] Cross-references to related applications

[0002] This application claims the benefit and priority of U.S. Provisional Application Serial No. 63 / 546,984, filed November 2, 2024, entitled “MANAGING A TRANSMISSIONCONFIGURATION INDICATOR STATE FOR LOWER LAYER TRIGGERED MOBILITY”, the entire contents of which are expressly incorporated herein by reference. Technical Field

[0003] This document relates to wireless communications, and more specifically, to configuring and activating the Transport Configuration Indicator (TCI) state for User Equipment (UE) before, during, and after Low Layer Mobility Triggering (LTM). Background Technology

[0004] This background description is provided for the purpose of generally presenting the context of the embodiments discussed later. The work of the currently nominated inventors (to the extent described in this background section) and aspects of this specification that might not have been considered prior art at the time of filing are neither expressly nor impliedly acknowledged as prior art in this document.

[0005] In telecommunications systems, the Packet Data Convergence Protocol (PDCP) sublayer of the radio protocol stack provides services such as user plane data transmission, encryption, and integrity protection. For example, the PDCP layer, defined for the Evolved Universal Terrestrial Radio Access (EUTRA) radio interface (see 3GPP Technical Specification (TS) 36.323) and New Radio (NR) (see 3GPP TS 38.323), provides the ordering of Protocol Data Units (PDUs) in the uplink direction (from the User Equipment, also known as the UE, to the Base Station (BS)) and the downlink direction (from the BS to the UE). Furthermore, the PDCP sublayer provides Signaling Radio Bearers (SRBs) and Data Radio Bearers (DRBs) to the Radio Resource Control (RRC) sublayer. Generally, the UE and BS can use SRBs to exchange RRC messages and Non-Access Stratum (NAS) messages, and can use DRBs to transmit data on the user plane.

[0006] UEs can use several types of SRBs and DRBs. When operating in dual connectivity (DC), the cell associated with the BS operating as the primary node (MN) defines the primary cell group (MCG), and the cell associated with the BS operating as the secondary node (SN) defines the secondary cell group (SCG). The so-called SRB1 resource carries RRC messages, which in some cases include NAS messages on the dedicated control channel (DCCH), and the SRB2 resource supports RRC messages including recorded measurement information or NAS messages, also on the DCCH but with a lower priority than the SRB1 resource. More generally, the SRB1 and SRB2 resources allow the UE and MN to exchange MN-related RRC messages and embed SN-related RRC messages, and can also be referred to as the MCG SRB. The SRB3 resource allows the UE and SN to exchange SN-related RRC messages and can be referred to as the SCG SRB. Split SRBs allow the UE to exchange RRC messages directly with the MN via lower-layer resources of the MN and SN. Furthermore, a DRB that uses only the low-level resources of MN can be called an MCG DRB, a DRB that uses only the low-level resources of SN can be called an SCG DRB, and a DRB that uses the low-level resources of both MCG and SCG can be called a split DRB.

[0007] In some scenarios, a UE can concurrently utilize the resources of multiple Radio Access Network (RAN) nodes (e.g., components of a BS or distributed BS) interconnected via backhaul. This type of connection is called Multiple Radio Dual Connectivity (MR-DC) when these network nodes support different Radio Access Technologies (RATs). When the UE operates under MR-DC, one BS operates as the primary node (MN) covering the primary cell (PCell), and another BS operates as the secondary node (SN) covering the primary secondary cell (PSCell). The UE communicates with the MN (via the PCell) and with the SN (via the PSCell). In other scenarios, the UE utilizes the resources of one BS at a time. One BS and / or the UE determines that the UE should establish a radio connection with another BS. For example, one BS may determine to hand over the UE to a second BS and initiate a handover procedure.

[0008] When a UE moves from the coverage area of ​​one cell in the RAN to another, a serving cell change must be performed for the UE at some point. To perform the serving cell change, the RAN configures the UE to send Layer 3 (L3) measurements. Based on the L3 measurements received from the UE, the RAN sends an RRC reconfiguration message, which configures a synchronized reconfiguration for changing the serving cell (e.g., PCell or PSCell). (For example, the RRC reconfiguration message includes...) ReconfigurationWithSync(IE). When a UE operates with carrier aggregation (CA) of at least one secondary cell (SCell) and either PCell or PSCell, the RAN must release at least one SCell due to the change of PCell or PSCell. Serving cell changes involve a complete Layer 2 (L2) (and Layer 1 (L1)) reset, resulting in longer latency, greater overhead, and longer downtime. Therefore, 3GPP recently launched a new work project to develop new mobility technologies for serving cell changes. These technologies aim to reduce latency and overhead and are known as Low Layer Triggered Mobility (LTM) cell handover, or faster serving cell handover. LTM can also be referred to as L1 / L2 triggered mobility.

[0009] LTM, also known as Network Triggered Mobility or Network Initiated Mobility, is a technology applicable to mobile networking and wireless communications. It refers to a type of mobility management where the decision to hand over a UE from one NE or BS to another is primarily determined by the lower layers of the network protocol stack (such as the physical and data link layers). In LTM, the network infrastructure (such as the BS or NE) initiates and controls the handover process based on low-layer (L1) criteria, such as signal strength, quality, and resource availability. When the UE's connection quality deteriorates below a certain threshold, the network infrastructure decides to trigger a handover and guides the UE to switch to a different NE or BS that can provide a better connection.

[0010] This approach contrasts with higher-layer triggered mobility, where handover decisions are primarily made by the UE itself or upper-layer network entities, such as the Mobility Management Entity (MME) in LTE / 4G or the Mobility Anchor in Mobile IP. In higher-layer triggered mobility, the UE actively scans for better networks and makes decisions based on higher-layer parameters such as network load, quality of service, or user preferences.

[0011] When the RAN communicates with the UE via the serving cell, the RAN receives one or more Layer 3 (e.g., RRC) measurement results from the UE. Based on the Layer 3 (L3) measurement results, the RAN determines an LTM candidate cell to configure for LTM cell handover. To configure the LTM candidate cell for the UE, the RAN sends the LTM configuration for the LTM candidate cell to the UE via RRC signaling. Later, the RAN receives one or more Layer 1 (L1) measurement results from the UE. Based on the one or more L1 measurement results, the RAN determines that the LTM candidate cell is eligible to become the UE's serving cell. Therefore, the RAN sends an LTM cell handover command to the UE, instructing the UE to perform an LTM cell handover to the LTM candidate cell. In response to the LTM cell handover command, the UE performs a cell change from the serving cell to the LTM candidate cell. In response to the cell change, the UE disconnects from the serving cell and accesses the LTM candidate cell. After the UE successfully accesses the LTM candidate cell, the UE communicates with the RAN via the LTM candidate cell, and the LTM candidate cell becomes the UE's new serving cell.

[0012] After the RAN configures LTM candidate cells and before sending the LTM cell handover command, the RAN may pre-activate one or more TCI states of the candidate cell before it becomes the serving cell. Note that TCI states relate to the management of control information transmitted on the Physical Downlink Shared Channel (PDSCH) in the downlink (from BS to UE). TCIs play a role in managing beamforming, spatial multiplexing, and other multiple-input multiple-output (MIMO) techniques to enhance network efficiency and performance. This allows the UE to synchronize with the candidate cell's downlink (DL), thereby facilitating a faster cell handover to one of these cells when the UE performs an LTM cell handover to the candidate cell. In 3GPP R2-2311250, a Candidate Cell TCI State Activation / Deactivation MAC CE is specified for the RAN to activate and deactivate one or more TCI states of LTM candidate cells, as shown below.

[0013]

[0014] The LTM RRC Operation Change Request (CR) is described in 3GPP R2-2310885, and the Physical Cell Identifier (PCI) is described in 3GPP TS 38.331.

[0015] As mentioned above, the candidate cell identifier ID in the MAC CE is 3 bits, while the candidate cell ID used for LTM (i.e., ltm-CandidatePCI-r18) is 10 bits, representing values ​​from 0 to 1007. The existing network is not configured to convert these 10 bits to the 3 bits in the candidate cell ID field of the MAC CE. Furthermore, the existing RAN is not configured to manage the TCI state of the candidate cell for the UE after it becomes the UE's serving cell. Summary of the Invention

[0016] Recently developed mobility technologies known as LTM reduce conventional cell handover latency and overhead because, with LTM, the UE does not require explicit Layer 3 RRC signaling. LTM execution can be triggered by L1 or L2 measurement reports. According to various embodiments, the LTM ID is used to identify both the LTM Distributed Cell (DU) configuration and the LTM TCI state configuration. According to other embodiments, the candidate cell ID, when used in LTM-related procedures, is calculated based on the PCI value according to a given formula. Therefore, a long-bit PCI (e.g., 10 bits) is converted to a short-bit candidate cell ID (e.g., 3 bits), and the LTM command conveys this long-bit PCI value via the required short-bit field without ambiguity. According to yet another embodiment, the UE determines whether the candidate cell is the serving cell. Based on this determination, the UE selectively exchanges signals with the RAN using one or more LTM TCI state configurations. Attached Figure Description

[0017] Figure 1A This is a block diagram of an example system in which the RAN and UE can implement the techniques described in this document for managing conditional processes related to LTM processes. Figure 1B This is a block diagram of an example BS, which includes components that can be... Figure 1A The system operates with centralized units (CU) and distributed units (DU); Figure 2 This is a block diagram showing the structural elements of a UE and a BS configured to perform a method for managing LTM configuration and TCI state according to one embodiment.

[0018] Figure 3 A first scenario of a UE and a network entity (NE) operating according to one embodiment is shown.

[0019] Figure 4 A second scenario of the UE and NE operating according to another embodiment is shown.

[0020] Figure 5A and Figure 5BA third scenario is shown, illustrating the operation of the UE and NE according to other embodiments.

[0021] Figure 6A and Figure 6B A fourth scenario is shown, in which the UE and NE operate according to other embodiments.

[0022] Figure 7A and Figure 7B A fifth scenario is shown, illustrating the operation of the UE and NE according to some embodiments.

[0023] Figure 8A and Figure 8B A sixth scenario of a UE and NE operating according to some other embodiments is shown.

[0024] Figures 9A to 9I A flowchart illustrating a method performed by a BS according to various embodiments is depicted.

[0025] Figures 10A to 10C A flowchart illustrating a method performed by a service DU of a BS according to various embodiments is depicted.

[0026] Figures 11A to 11B A flowchart illustrating a method performed by a target DU according to various embodiments is depicted.

[0027] Figures 12A to 12C Flowcharts illustrating other methods performed by the BS service DU according to various embodiments are depicted.

[0028] Figure 13A and Figure 13B A flowchart illustrating a method performed by the CU of the BS according to various embodiments is depicted.

[0029] Figures 14A to 14I A flowchart illustrating a method performed by a UE according to various embodiments is depicted.

[0030] Figures 15A to 15D Flowcharts illustrating other methods performed by the UE after the target cell becomes the serving cell, according to various embodiments, are depicted. Detailed Implementation

[0031] Figure 1AAn example wireless communication system 100 in which communication devices can implement these technologies is depicted. The wireless communication system 100 includes a UE 102, a first BS 104, a second BS 106, and a core network (CN) 110. The UE 102 is initially connected to the first BS 104. In some scenarios, the first BS 104 can perform SN addition to configure the UE 102 to operate in dual connectivity (DC) with both the first BS 104 and the second BS 106. The first BS 104 and the second BS 106 serve as the MN and SN for the UE 102, respectively.

[0032] In various configurations of the wireless communication system 100, the first BS 104 can be implemented as a primary eNB (MeNB) or a primary gNB (MgNB), and the second BS 106 can be implemented as a secondary gNB (SgNB). The UE 102 can communicate with the first BS 104 and the second BS 106 via the same RAT (such as EUTRA or NR) or different RATs. When the first BS 104 is a MeNB and the second BS 106 is an SgNB, the UE 102 can be in an EUTRA-NR DC (EN-DC) with both the MeNB and the SgNB.

[0033] In some cases, the MeNB or SeNB is implemented as an ng-eNB instead of an eNB. When the first BS 104 is the primary ng-eNB (Mng-eNB) and the second BS 106 is the SgNB, the UE 102 can be in a next-generation (NG) EUTRA-NR DC (NGEN-DC) with both the Mng-eNB and the SgNB. When the first BS 104 is the MgNB and the second BS 106 is the SgNB, the UE 102 can be in an NR-NR DC (NR-DC) with both the MgNB and the SgNB. When the first BS 104 is the MgNB and the second BS 106 is the secondary ng-eNB (Sng-eNB), the UE 102 can be in an NR-EUTRA DC (NE-DC) with both the MgNB and the Sng-eNB.

[0034] In the scenario where UE 102 switches from the first BS 104 to the second BS 106, the first BS 104 and the second BS 106 operate as the source BS (S-BS) and the target BS (T-BS), respectively. UE 102 can, for example, communicate with the first BS 104 and the additional BS (T-BS) before the handover. Figure 1A(Not shown in the diagram) operates in DC mode. UE 102 can continue to operate in DC mode with the second BS 106 and the additional BS after the handover is completed, or operate in single-connection (SC) mode with the second BS 106. In this case, BS 104 and 106 operate as the source MN (S-MN) and the target MN (T-MN), respectively.

[0035] The core network (CN) 110 can be either the Evolved Packet Core (EPC) 111 or the 5th Generation Core (5GC) 160; both are... Figure 1A The first BS 104 may be an eNB supporting an S1 interface for communication with EPC 111, an ng-eNB supporting an NG interface for communication with 5GC160, or a gNB supporting an NR radio interface and an NG interface for communication with 5GC 160. BS 104 and 106 may support X2 or Xn interfaces to exchange messages directly with each other during the scenarios discussed below. Among other components, EPC 111 may include a Serving Gateway (SGW) 112, a Mobility Management Entity (MME) 114, and a Packet Data Network Gateway (PGW) 116. SGW 112 is generally configured to transmit user plane packets related to audio calls, video calls, Internet services, etc., and MME 114 is configured to manage authentication, registration, paging, and other related functions. PGW 116 provides connectivity from the UE to one or more external packet data networks (e.g., Internet networks and / or Internet Protocol (IP) Multimedia Subsystem (IMS) networks). 5GC 160 includes User Plane Functions (UPF) 162, Access and Mobility Management (AMF) 164, and / or Session Management Functions (SMF) 166. UPF 162 is typically configured to transmit user plane packets related to audio calls, video calls, Internet services, etc., AMF 164 is configured to manage authentication, registration, paging, and other related functions, and SMF 166 is configured to manage PDU sessions.

[0036] like Figure 1A As shown, the first BS 104 supports cell 124A, and the second BS 106 supports cell 126. Note that the cell shapes and sizes are not drawn to scale, and cells can have various shapes. Cells 124A and 126 can partially overlap, allowing UE 102 to communicate with the first BS 104 and the second BS 106 via DC, where one of BS 104 and 106 is the MN and the other is the SN. The first BS 104 can support additional cells, such as cells 124B and 124C, and the second BS 106 can support additional cells (…). Figure 1A(Not shown in the diagram). Cells 124A, 124B, and 124C may partially overlap, enabling UE 102 to communicate with the first BS 104 via carrier aggregation (CA). The first BS 104 may operate cells 124A, 124B, and 124C via one or more transmit and receive points (TRPs). More specifically, when UE 102 is in a DC with the first BS 104 and the second BS 106, one of BS 104 and 106 operates as a MeNB, Mng-eNB, or MgNB, while the other operates as an SgNB or Sng-eNB.

[0037] Typically, the wireless communication network 100 may include any suitable number of BSs supporting NR cells and / or EUTRA cells. More specifically, the EPC 111 or 5GC 160 may connect to any suitable number of BSs supporting NR cells and / or EUTRA cells. Although the examples below specifically refer to particular CN types (EPC, 5GC) and RAT types (5G NR and EUTRA), the techniques in this document can generally be applied to other suitable radio access and / or core network technologies, such as sixth-generation (6G) radio access and / or 6G core network or 5G NR-6G DC.

[0038] Continue to refer to Figure 1AThe first BS 104 is equipped with processing hardware 130, which may include one or more general-purpose processors (e.g., CPUs) and a non-transitory computer-readable storage medium containing instructions that are executed by the one or more general-purpose processors. Additionally or alternatively, the processing hardware 130 may include dedicated processing units. The processing hardware 130 may include a PHY controller 132 configured to transmit data and control signals on a physical downlink (DL) channel and DL reference signals with one or more user equipments (e.g., UE 102) via one or more cells (e.g., cells 124A, 124B, and / or 124C) and / or one or more TRPs. The PHY controller 132 is also configured to receive data and control signals on a physical uplink (UL) channel and / or UL reference signals with one or more user equipments via one or more cells (e.g., cells 124A, 124B, and / or 124C) and / or one or more TRPs. In an example implementation, the processing hardware 130 includes a MAC controller 134 configured to perform MAC functions with one or more user equipments. The MAC functions include random access (RA) procedures, managing UL timing advances for the one or more user equipments, and / or communicating UL / DL MAC PDUs with the one or more user equipments. The MAC functions include low-layer triggered mobility (LTM) related functions as described below. Processing hardware 130 may further include an RRC controller 136 to implement procedures and messaging at the RRC sublayer of the protocol communication stack. For example, RRC controller 132 may be configured to support RRC messaging associated with handover procedures, and / or support necessary operations when the first BS 104 operates as an MN relative to the SN or as an SN relative to the MN. The second BS 106 may include processing hardware 140 similar to processing hardware 130. Specifically, components 142, 144, and 146 may be similar to components 132, 134, and 136, respectively.

[0039] UE 102 is equipped with processing hardware 150, which may include one or more general-purpose processors such as a CPU, and non-transitory computer-readable memory storing machine-readable instructions executable on the one or more general-purpose processors, and / or dedicated processing units. PHY controller 152 is also configured to receive data and control signals on the physical DL channel and / or DL ​​reference signal via one or more cells (e.g., cells 124A, 124B, 124C, and / or 126) and / or one or more TRPs with the first BS 104 or 106. PHY controller 152 is also configured to transmit data and control signals on the physical UL channel and / or UL reference signal via one or more cells (e.g., cells 124A, 124B, 124C, and / or 126) and / or one or more TRPs with the first BS 104 or 106. In an example implementation, processing hardware 150 includes MAC controller 154, which is configured to perform MAC functions with the first BS 104 or the second BS 106. For example, MAC functions include random access procedures, managing UL timing advances for the one or more user facilities, and communicating UL / DL MAC PDUs with the first BS 104 or 106. In another example, MAC functions include LTM-related functions as described below. Processing hardware 150 may further include an RRC controller 156 to implement procedures and message passing at the RRC sublayer of the protocol communication stack.

[0040] In operation, UE 102 in the DC can use radio bearers (e.g., DRB or SRB) that terminate at MN 104 or SN 106 at different times. When communicating on this radio bearer in the uplink (UL) (from UE 102 to BS) and / or downlink (from BS to UE 102) directions, UE 102 can apply one or more security keys.

[0041] Figure 1BAn example distributed implementation of a BS (such as a first BS 104 or 106) is depicted. In this implementation, the BS may include a centralized unit (CU) 172 and one or more distributed units (DUs) 174. The CU 172 is equipped with processing hardware, which may include one or more general-purpose processors (such as a CPU) and non-transitory computer-readable memory storing machine-readable instructions executable on the one or more general-purpose processors, and / or dedicated processing units. In one example, the CU 172 is equipped with processing hardware 130. In another example, the CU 172 is equipped with processing hardware 140. In the example implementation, the processing hardware 140 includes an SN RRC controller 142 configured to manage or control one or more RRC configurations and / or RRC processes when the second BS 106 operates as an SN. DU 174 is also equipped with processing hardware, which may include one or more general-purpose processors (such as a CPU) and non-transitory computer-readable memory storing machine-readable instructions executable on the one or more general-purpose processors, and / or dedicated processing units. In some examples, the processing hardware in the example implementation includes: a Media Access Control (MAC) controller configured to manage or control one or more MAC operations or procedures (e.g., random access procedures); and a Radio Link Control (RLC) controller configured to manage or control one or more RLC operations or procedures when the second BS 106 operates as an MN or SN. The processing hardware may further include a physical layer controller configured to manage or control one or more physical layer operations or procedures.

[0042] Figure 2 This is a block diagram illustrating the structural elements of a UE and an NE (e.g., a BS), configured to perform a method for managing LTM according to one embodiment. NE 204 (which can be used as...) Figure 1A 104, 106, Figure 1B (170 operation in the middle) and UE 102 wireless communication. NE 204 can be BS, but more generally, the term "network entity" represents a wireless device with well-defined network functions (e.g., the function of a BS is to connect the UE to the core network, including managing communications to and from the UE).

[0043] NE 204 can provide gNB (i.e., 5G or 6G base station) functionality. The functionality of NE 204 can be distributed across multiple entities (e.g., central unit CU, distributed unit DU, and radio unit RU). NE 204 includes an antenna, a radio frequency (RF) front-end 281, and a transceiver 282 for communicating with UE 102 and other UEs and NEs. The antenna and RF front-end 281 of NE 104 / 106 can be tuned to one or more frequency bands (e.g., subcarriers), as defined by 3GPP LTE, 5G NR, and 6G communication standards and implemented by transceiver 282.

[0044] NE 204 further includes a processor 283 and a computer-readable storage medium (CRM) 284. The processor 283 may include a single-core or multi-core processor, and the CRM 284 includes any suitable memory / storage device other than propagating signals. For example, the memory / storage device may include random access memory (RAM), static RAM, dynamic RAM, non-volatile RAM, read-only memory (ROM), and / or flash memory. The CRM 284 stores device data 285, which includes network scheduling data, radio resource management data, applications, and / or operating systems, which can be executed by the processor 283 to enable wireless communication with UE 102 and other NEs and UEs.

[0045] CRM 284 also stores L1 measurement configurator 286 and LTM control-related executable instructions 287. NE 104 / 106 also includes an inter-base station interface 288 and a core network interface 289. The inter-base station interface 288 can be a standardized interface, such as an Xn and / or X2 interface, used to exchange user plane and control plane data with another NE (e.g., in handover situations). The core network interface 289 enables the exchange of user plane data and control plane information between the NE and core network functions and / or entities.

[0046] UE 102 includes an antenna connected to RF front-end 291 and a transceiver 292. The UE may include multiple transceivers to support various technologies. The antenna and RF front-end 291 may be tuned to one or more frequency bands (e.g., subcarriers), as defined by 3GPP LTE, 5G NR, and 6G communication standards and implemented by the corresponding transceivers. UE 102 also includes one or more processors 293 and a computer-readable storage medium (CRM) 294. The processor 293 may be a single-core or multi-core processor, and the CRM 294 includes any suitable memory / storage device other than propagating signals. For example, the memory / storage device may include random access memory (RAM), static RAM, dynamic RAM, non-volatile RAM, read-only memory (ROM), and / or flash memory. The CRM 294 stores device data 295 necessary for the UE's communication, an L1 measurement and report generator 296, and LTM control-related executable instructions 297.

[0047] In some embodiments, the L1 measurement and LTM execution of the NE and UE can be implemented not only as software, but also as hardware logic and / or circuitry.

[0048] The following describes several example scenarios, in which... Figure 1A The BS operating in the system sends configuration to UE 102 and later activates the configuration for communication between UE 102 and the BS. Generally speaking, Figures 3 to 7B Similar events are labeled with similar reference numbers (e.g., event 316 is similar to...). Figure 4 A and Figure 4 Event 416 of B Figure 5A Event 516 Figure 5B Event 517 Figure 6A Event 616 Figure 6B Event 617 Figure 7A Event 716, and Figure 7B Event 717), where the differences are discussed below where appropriate. Apart from the differences shown in the figures and discussed below, any alternative implementations discussed for a particular event (e.g., for messaging and processing) may be applied to other events in the figures labeled with similar reference numerals.

[0049] Referring first to 3, in scenario 300, the first BS 104 includes CU 172 and DU 174, and DU 174 operates in cell 124A. UE 102 initially communicates with DU 174 on cell 124A using the serving DU configuration 302, and communicates with CU 172 via DU 174, for example, using the serving CU configuration. In other words, DU 174 is the serving DU that communicates with UE 102. In some implementations, UE 102 uses the serving DU configuration to communicate with DU 174 via carrier aggregation (CA) on cell 124A and other cells (e.g., cell 124D, not shown in FIG. 1A). DU 174 operates in the other cells. Cell 124A and / or the other cells are serving cells for UE 102. In other implementations, UE 102 communicates with DU 174 only on cell 124A. In some implementations, UE 102 communicates with DU 174 via one or more TRPs on cell 124A and / or other cells. In some implementations, cell 124A may be a PCell. In such cases, the other cells include SCells and / or additional cells associated with a PCell or SCell. In other implementations, cell 124A may be an SCell, and one of the other cells is a PCell. In such cases, the remaining cells include SCells and / or additional cells associated with a PCell or SCell. In the following description, the first BS 104 may be DU 174, CU 172, or DU 174 and CU 172.

[0050] In event 302, UE 102 may transmit UL PDUs and / or UL control signals to the first BS 104 via one or more TRPs in cell 124A and / or other cells. In some implementations, UE 102 communicates UL PDUs and / or DL ​​PDUs with the first BS 104 via a radio bearer, which may include SRBs and / or DRBs. The first BS 104 may configure the radio bearer for UE 102. In some implementations, the UL control signals include UL control information, channel state information, Hybrid Automatic Repeat Request (HARQ) acknowledgment (ACK), HARQ negative ACK, scheduling request, and / or probe reference signals. Similarly, UE 102 may receive DL PDUs and / or DL ​​control signals from the first BS 104 via one or more TRPs in cell 124A and / or other cells. In some implementations, the DL control signals include downlink control information (DCI) and reference signals (e.g., synchronization signal steps, channel state information reference signals (CSI-RS), and / or tracking reference signals). The first BS 104 can transmit DCI via one or more TRPs on the physical downlink control channel (PDCCH) monitored by UE 102 in cell 124A and / or other cells.

[0051] In some implementations, the serving DU configuration includes physical layer configuration parameters, MAC configuration parameters, and / or RLC configuration parameters. In some implementations, the serving DU configuration includes at least one first non-LTM TCI state configuration for the serving cell. The term "at least one first configuration" is used in this document to refer to one or more configurations from a given configuration set (set one in this example). The term "non-LTM TCI state configuration" refers to a TCI state configuration used without LTM, i.e., a TCI state configuration used with a legacy 5G network, such as L3 messaging (higher layers) rather than L1 / L2 messaging (lower layers). Note that the term "at least one" is used in this document to refer to one element in a set or multiple elements in a set. In some implementations, DU 174 may send these configuration parameters and / or the first non-LTM TCI state configuration to CU 172. CU 172 generates one or more messages (e.g., RRC reconfiguration messages) that include these configuration parameters and / or the first non-LTM TCI state configuration and sends these messages to UE 102 via DU 174. In other implementations, DU 174 directly sends these configuration parameters and / or the first non-LTM TCI state configuration to UE 102. In some implementations, the serving DU configuration is defined in 3GPP TS 38.331. CellGroupConfig IE. In other implementations, the service DU configuration includes... CellGroupConfigConfiguration parameters in IE. In some implementations, the service CU configuration includes PDCP configuration parameters, measurement configuration parameters, and / or radio bearer configuration parameters. In some implementations, the service CU configuration includes those defined in 3GPP TS 38.331. MeasConfig IE and / or RadioBearerConfig IE, or including MeasConfig IE and / or RadioBearerConfig Configuration parameters in IE. In some implementations, the service DU configuration includes... CSI-MeasConfig IE or configuration parameters used for Channel State Information (CSI) measurement and reporting. In other implementations, the service CU configuration includes... CSI-MeasConfig IE or configuration parameters used for CSI measurement and reporting. In some implementations, UE 102 receives the service CU configuration or configuration parameters in the service CU configuration from CU 172 via DU 174. In other implementations, UE 102 receives a portion of the service CU configuration and / or a portion of the service DU configuration from a BS other than the first BS 104, and receives the remainder of these configuration parameters from the first BS 104.

[0052] In some implementations, UE 102 and DU 174 communicate with each other using a first non-LTM TCI state configuration, for example, in events 302, 318, 320, 324, 325, 330, and / or 331. In some implementations, DU 174 sends at least one first non-LTM TCI state activation / deactivation command to UE 102 to activate some first non-LTM TCI state configurations. UE 102 activates these first non-LTM TCI state configurations in response to the first non-LTM TCI state activation / deactivation command. In some implementations, DU 174 indicates deactivation of some of the first non-LTM TCI state configurations in some of the first non-LTM TCI state activation / deactivation commands. UE 102 and DU 174 communicate with each other using the activated non-LTM TCI state configurations, for example, in events 302, 318, 320, 324, 325, 330, and / or 331.

[0053] In some implementations, each of the first non-LTM TCI state activation / deactivation commands is a MAC CE. MAC CEs may include: one or more TCI state activation / deactivation MAC CEs for UE-specific PDSCHs, one or more TCI state indication MAC CEs for UE-specific PDCCHs, one or more PUCCH spatial relationship activation / deactivation MAC CEs, one or more enhanced TCI state activation / deactivation MAC CEs for UE-specific PDSCHs, one or more enhanced PUCCH spatial relationship activation / deactivation MAC CEs, one or more enhanced TCI state indication MAC CEs for UE-specific PDCCHs, one or more PUCCH spatial relationship activation / deactivation MAC CEs for multi-TRP PUCCH repetition, and / or one or more unified TCI state activation / deactivation MAC CEs.

[0054] In some implementations, DU 174 includes a serving cell ID (e.g., a serving cell index; however, while the cell ID is a unique identifier assigned to each cell, the cell index refers to an identifier used for accessing or referencing a specific cell, and the cell index may not necessarily be a unique identifier) ​​in each first non-LTM TCI state activation / deactivation command to identify the first non-LTM TCI state configuration. Each serving cell ID indicates the corresponding serving cell among the serving cells. In some implementations, the serving DU configuration includes the serving cell ID and configures the association between the serving cell ID and the first non-LTM TCI state configuration.

[0055] When communicating with the first BS 104, UE 102 sends at least one measurement report (304) to DU 174. In some implementations, the at least one measurement report includes Layer 1 (L1) measurement reports and / or Layer 3 (L3) measurement reports for at least one serving cell and / or at least one non-serving cell of UE 102. For each of the L3 measurement reports, DU 174 sends a DU-to-CU message (306) including the L3 measurement report to CU 172. In some implementations, the DU-to-CU message of event 306 is an F1 Application Protocol (F1AP) message (e.g., a UL RRC message delivery message). In some implementations, DU 174 does not send or avoids sending L1 measurement reports to CU 172. At least one serving cell includes cell 124A and / or other cells, and at least one non-serving cell includes cell 124B and / or cell 124C. In some implementations, the serving DU configuration or serving CU configuration includes at least one measurement configuration. In some implementations, in event 302, UE 102 receives one or more RRC messages (e.g., including at least one measurement configuration) from CU172 via DU 174. RRCReconfiguration (Message). Based on the at least one measurement configuration, UE 102 performs measurements and sends a 304 report of the at least one measurement to DU 174. In some implementations, the at least one measurement configuration includes an L3 measurement configuration (e.g., MeasConfig IE) and / or L1 measurement configuration. L1 measurement configuration (e.g., CSI-MeasConfig The IE (Internet Interface) may include L1 measurement resource configuration and / or L1 measurement reporting configuration. L1 measurement resource configuration can configure reference signals and / or resources for reference signals for UE 102 to measure and obtain L1 measurement results. In some implementations, reference signals include CSI-RS and / or Synchronization Signal (SS) / Physical Broadcast Channel (PBCH) resource steps (SSBs). For example, the L1 measurement resource configuration is... CSI-ResourceConfig IE. In another example, the L1 measurement report configuration configures how UE 102 sends L1 measurement results / reports. For example, the L1 measurement report configuration is... CSI-ReportConfig For example, UE 102 sends an L3 measurement report to CU 172 via DU 174 according to an L3 measurement configuration. UE 102 sends an L1 measurement report to DU 174 according to an L1 measurement configuration or an L1 measurement report configuration. In one implementation, DU 174 does not send an L1 measurement report to CU 172.

[0056] In some implementations, the L1 measurement configuration is a new RRC IE (defined in 3GPPTS 38.331) for low-layer triggered mobility (LTM). In some implementations, the L1 measurement resource configuration is a new RRC IE (defined in 3GPPTS 38.331) for LTM. In some implementations, the L1 measurement reporting configuration is a new RRC IE (defined in 3GPPTS 38.331) for LTM. In some implementations, each of the L1 measurement reporting configurations may include a trigger event configuration that configures a trigger event to trigger UE 102 to send an L1 measurement report. If UE 102 detects a trigger event, UE 102 sends an L1 measurement report to DU 174.

[0057] In some implementations, each of the L1 measurement reports may include at least one L1 measurement result. In some implementations, at least one L1 measurement result includes at least one L1-reference received signal power (L1-RSRP) value and / or at least one L1-signal-to-interference-noise ratio (L1-SINR) value. In some implementations, for each of the L1 measurement reports, UE 102 sends a PUCCH transmission including the L1 measurement report to DU 174. That is, UE 102 sends each of the L1 measurement reports to DU 174 on the PUCCH. In other implementations, for each of the L1 measurement reports, UE 102 sends a PUSCH transmission including the L1 measurement report to DU 174. That is, UE 102 sends each of the L1 measurement reports to DU 174 on the PUSCH. In other implementations, UE 102 sends a portion of the L1 measurement report to DU 174 on the PUCCH and the remainder of the L1 measurement report to the DU on the Physical UL Shared Channel (PUSCH). That is, for each portion of the L1 measurement report, UE 102 sends a PUCCH transmission including the L1 measurement report to DU 174, and for each remaining portion of the L1 measurement report, UE 102 sends a PUSCH transmission including the L1 measurement report to DU 174. In some implementations, each of the L1 measurement reports is part of a CSI (i.e., a CSI component) or a CSI. In some implementations, UE 102 may include other CSI components in each of the PUCCH and / or PUSCH transmissions described above. In one implementation, other CSI components include, for example, the Channel Quality Indicator (CQI), Precoding Matrix Indicator (PMI), CSI-RS Resource Indicator (CRI), SSB Resource Indicator (SSBRI), Layer Indicator (LI), and / or Rank Indicator (RI). In some implementations, UE 102 does not send L1 measurement reports to DU 174 in the format of an RRC message.

[0058] In some implementations, each of the L3 measurement reports may include at least one L3 measurement result. In some implementations, at least one L3 measurement result includes at least one RSRP (value) and / or at least one SINR (value). In one implementation, UE 102 transmits each of the L3 measurement reports to CU 172 on the PUSCH via DU 174. In some implementations, each of the L3 measurement reports may be an RRC message (e.g., Measurement Report (Message). In some implementations, each in the L3 measurement configuration includes a specific measurement identifier (e.g., measIdEach L3 measurement report includes a specific measurement identifier in a specific L3 measurement configuration. When CU 172 receives an L3 measurement report including the measurement identifier and L3 measurement results from UE 102 via DU 174, CU 172 can determine that the L3 measurement report is associated with an L3 measurement configuration identified by the measurement identifier.

[0059] In some alternative implementations, for each of at least one measurement report (e.g., an L1 measurement report), in event 304, UE 102 sends a MAC control element (CE) including the measurement report to DU 174. In order to send the MAC CE, in event 304, UE 102 generates one or more MAC PDUs to DU 174, each MAC PDU including one or more of the MAC CEs.

[0060] In some implementations, UE 102 performs measurements on one or more reference signals according to the at least one measurement configuration. The one or more reference signals may include one or more Synchronization Signal (SS) / Physical Broadcast Channel (PBCH) Resource Steps (SSBs) and / or one or more CSI-RSs. UE 102 obtains at least one L1 measurement result and / or at least one L3 measurement result from the measurements. DU 174 in cell 124A and other cells (e.g., cell 124B, cell 124C and / or Figure 1A The reference signal is transmitted on one or more cells (not shown in the diagram).

[0061] Upon receiving one or more of the at least one measurement report from UE 102 (e.g., in response to this), the first BS 104 (i.e., CU 172 or DU 174) determines a first cell (e.g., cell 124B) for UE 102 to prepare for LTM. In some implementations, the first BS 104 determines to prepare the first cell for UE 102 because the at least one measurement report indicates that the first cell can be used by the first BS 104 to communicate with UE 102. In some implementations, the first BS 104 determines to prepare the first cell for UE 102 because the at least one measurement report indicates that the first cell is eligible to be a candidate cell that can be used for communication with UE 102. In some implementations, CU 172 determines to prepare the first cell for UE 102 if the L3 measurement report indicates that the signal strength and / or quality of the first cell is higher than a first predetermined threshold, better than the strength and / or quality of cell 124A, and / or better than the strength and / or quality of cell 124A by the first predetermined threshold. In other implementations, if the L1 measurement report indicates that the signal strength and / or quality of the first cell is higher than a first predetermined threshold, better than the signal strength and / or quality of cell 124A, and / or better than the signal strength and / or quality of cell 124A by a first predetermined threshold, then DU 174 determines to prepare the first cell for UE 102. Alternatively, the first BS 104 determines to prepare the first cell for UE 102 regardless of whether a measurement report is received from UE 102.

[0062] If CU 172 determines that a first cell is ready for LTM, CU 172 sends a 308 First CU to DU message to DU 174 to prepare the first cell for UE 102. In some implementations, CU 172 includes the cell identifier (ID) 1 of the first cell in the First CU to DU message to request DU 174 to prepare the first cell for UE 102 for LTM. For example, cell ID 1 is the Cell Global Identifier (CGI). In another example, the cell ID is part of the CGI. In yet another example, the cell ID is the Physical Cell ID (PCI). In some implementations, CU 172 includes an LTM indicator in the First CU to DU message to instruct DU 174 to prepare the first cell for LTM. In some implementations, the LTM indicator is... LTM information to be established IE or want Modified LTM informationIE. In response to the first CU to DU message, DU 174 generates a first LTM DU configuration (hereinafter referred to as LTM DU configuration 1) for UE 102 for the first cell with LTM configuration. DU 174 then sends a first DU to CU 172 including LTM DU configuration 1 in response to the first CU to DU message. In some implementations, DU 174 may include cell ID 1 along with LTM DU configuration 1 in the IE of the first DU to CU message to indicate that LTM DU configuration 1 is associated with the first cell (i.e., cell ID 1). DU 174 initiates the transmission of the first DU to CU message to CU 172 in response to a CU to DU message received from CU 172, provided that the first cell is ready.

[0063] In some implementations, DU 174 includes the cell ID of the first cell associated with LTM DU configuration 1 in the first DU to CU message to indicate that LTM DU configuration 1 is configured for or associated with the first cell. CU 172 identifies that LTM DU configuration 1 is configured for or associated with the first cell. In some scenarios and implementations, CU 172 may include additional cell IDs (e.g., cell ID 2, ..., N) in the first CU to DU message to prepare additional cells (e.g., cell 2, ..., N) for UE 102 for LTM, and DU 174 includes additional LTM DU configurations (e.g., LTM DU configuration 2, ..., N), each additional LTM DU configuration configuring a specific cell in the additional cells, as described below. In such cases, DU 174 includes the additional cell IDs associated with each additional LTM DU configuration in the first DU to CU message to indicate which LTM DU configuration is associated with which cell (ID). Cell 1 and / or 2, ..., N are candidate cells.

[0064] In some implementations, CU 172 does not include the (reference) LTM DU configuration in the first CU-DU message. In such cases, DU 174 generates a reference LTM DU configuration, generates LTM DU configurations 1 and / or 2, ..., N (i.e., non-reference LTM DU configurations) based on the reference LTM DU configuration, and includes the reference LTM DU configuration in the first DU-CU message. In other implementations, CU 172 includes the reference LTM DU configuration in the first CU-DU message. In such cases, DU 174 generates LTM DU configurations 1 and / or 2, ..., N, which are incremental configurations used to enhance the reference LTM DU configuration. In yet another implementation, CU 172 includes the reference LTM DU configuration (e.g., the first reference LTM DU configuration) in the first CU-DU message. In such cases, DU 174 generates a reference LTM DU configuration (e.g., a second reference LTM DU configuration) to replace the first reference LTM DU configuration, generates LTM DU configuration 1 and / or 2, ..., N based on the second reference LTM DU configuration, and includes the second reference LTM DU configuration in the first DU to CU message.

[0065] In some implementations, the reference LTM DU configuration includes physical layer configuration parameters, MAC configuration parameters, and / or RLC configuration parameters. In other implementations, the reference LTM DU configuration is as defined in 3GPP TS 38.331. CellGroupConfig IE. In other implementations, refer to the LTM DU configuration, including... CellGroupConfig Configuration parameters in IE. In some implementations, referencing the LTM DU configuration includes... CSI-MeasConfig IE or configuration parameters used for Channel State Information (CSI) measurement and / or reporting.

[0066] In some implementations, the reference LTM DU configuration differs from the service DU configuration. In some implementations, a portion of the reference LTM DU configuration is identical to a portion of the service DU configuration, while the remainder of the reference LTM DU configuration differs from the remainder of the service DU configuration. In other implementations, the reference LTM DU configuration is identical to the service DU configuration.

[0067] After receiving the first DU to CU message, CU 172 generates an RRC reconfiguration message including LTM DU configuration 1 (e.g., RRCReconfigurationThe CU 172 sends a second CU-DU message 316, which includes an RRC reconfiguration message, to DU 174. In some implementations, CU 172 includes the reference LTM DU configuration in the RRC reconfiguration message 316. In other implementations, CU 172 does not include the reference LTM DU configuration in the RRC reconfiguration message 316. In some implementations, if CU 172 sends the reference LTM DU configuration to UE 102 during event 302, then CU 172 does not include the reference LTM DU configuration in the RRC reconfiguration message 316. In other implementations, if CU 172 receives the reference LTM DU configuration from DU 174, then CU 172 includes the LTM DU configuration in the RRC reconfiguration message 316. Otherwise, if CU 172 does not receive the reference LTM DU configuration from DU 174, then CU 172 does not include the reference LTM DU configuration in the RRC reconfiguration message 316.

[0068] In some implementations, CU 172 includes LTM DU configuration 1 and / or LTM CU configuration 1 in a first container (e.g., field / IE), and includes the first container (e.g., LTM configuration 1) in the RRC reconfiguration messages of events 316 and 318. In such cases, CU 172 generates the first container. The first container is used to indicate to UE 102 that LTM DU configuration 1 and / or LTM CU configuration 1 should not be applied immediately. In some scenarios and implementations, UE 102 receives an RRC reconfiguration message (e.g., RRC reconfiguration message of event 318) that includes the configuration (e.g., LTM DU configuration 1). If the configuration is included in the first container, UE 102 avoids applying the configuration immediately. Otherwise, if the configuration is not included in the first container, UE 102 can apply the configuration immediately. In some implementations, the first container includes or is a first add or modify list (e.g., ltm- CandidateToAddModList field or LTM-CandidateToAddModList IE). CU 172 includes LTM DU configuration 1 and / or LTM CU configuration 1 in the first element (hereinafter referred to as element 1) of the first add or modify list. In some implementations, CU 172 generates an RRC message that includes LTM DU configuration 1 and / or LTM CU configuration 1 (e.g., RRCRecconfiguration The message), and includes the RRC message in element 1. In some implementations, element 1 is for adding or modifying IE (e.g., LTM-ConfigToAddMod IE LTM-Candidate IE LTM- CandidateToAddMod IE or LTM-CandidateConfigToAddMod(IE). When UE 102 receives the first add or modify list, UE 102 may store the first add or modify list (e.g., in a variable stored in its random access memory (RAM)). In other alternative implementations, DU 174 generates a first container and includes the first container in the first DU to CU message. In yet another alternative implementation, DU 174 generates element 1 and includes element 1 in the first DU to CU message.

[0069] In some implementations, CU 172 includes LTM CU configuration 1 in RRC reconfiguration message 316, the first container, or element 1, where LTM CU configuration 1 is associated with LTM DU configuration 1. To associate LTM CU configuration 1 with LTM DU configuration 1, CU 172 may include LTM CU configuration 1 and LTM DU configuration 1 in element 1. In some implementations, CU 172 includes LTM CU configurations 2, ..., N in RRC reconfiguration message 316 or the second container, where LTM CU configurations 2, ..., N are associated with LTM DU configurations 2, ..., N, respectively. To associate LTM CU configurations 2, ..., N with LTM DU configurations 2, ..., N, CU 172 may include LTM CU configurations 2, ..., N and LTM DU configurations in elements 2, ..., N, respectively. In other implementations, CU 172 includes the LTM CU configurations 2, ..., N associated with LTM DU configurations 2, ..., N in elements 2, ..., N, respectively. Alternatively, CU 172 does not include some or all of the LTM CU configurations for LTM DU configuration 1 and / or LTM DU configurations 2, ..., N in the RRC reconfiguration message 316.

[0070] After receiving RRC reconfiguration message 316, DU 174 sends RRC reconfiguration message 318 to UE 102. In response, UE 102 sends RRC reconfiguration complete message 320 to DU 174 (e.g., RRCReconfigurationCompleteThe DU then sends a second DU-to-CU message (322) to CU 172, which includes an RRC reconfiguration completion message. In some implementations, CU 172 performs security protection on the RRC reconfiguration message (e.g., integrity protection and / or encryption). For example, CU 172 generates an integrity message authentication code (MAC-I) for the RRC reconfiguration message, encrypts the RRC reconfiguration message and MAC-I to obtain an encrypted RRC reconfiguration message and an encrypted MAC-I, and sends a PDCP PDU including the encrypted RRC reconfiguration message and the encrypted MAC-I to UE 102 via DU 174 in events 316 and 318. When UE 102 receives the PDCP PDU from CU 172 via DU 174 (i.e., events 316 and 318), UE 102 decrypts the encrypted RRC reconfiguration message and the encrypted MAC-I to obtain the RRC reconfiguration message and MAC-I and verifies whether the MAC-I is valid. If UE 102 verifies an invalid MAC-I, UE 102 discards or ignores the RRC reconfiguration message. In some implementations, UE 102 may perform an RRC connection reconstruction procedure in response to an invalid MAC-I. Otherwise, if UE 102 verifies a valid MAC-I, UE 102 may process the RRC reconfiguration. UE 102 avoids applying (i.e., executing) LTM DU configuration 1 until it receives an LTM command to activate LTM DU configuration 1, as described for events 330 and 350.

[0071] Events 308 (optional) and 310 in Figure 3 This is collectively referred to as LTM preparation process 390. Events 316, 318, 320, and 322 are... Figure 3 This is collectively referred to as the LTM configuration transfer process 394.

[0072] In some implementations, the first CU to DU message is UE Context Modification Request The message, and the first DU to CU message is UE context modification response or UE context modification requirements Message. In UE context modification requirements In the case of a message, CU 172 can respond to UE context modification requirements Message sent to DU 174 UE context modification confirmation Message. In some implementations, the second CU to DU message is DL RRC message transmission In other implementations, the second CU to DU message is a UE context modification request message. In some implementations, the second DU to CU message is... UL RRC message transmission In other implementations, the second DU to CU message is a UE context modification response message.

[0073] In some implementations, CU 172 may include the reference LTM CU configuration in RRC reconfiguration message 316 or the first container. In some implementations, CU 172 may generate LTM CU configuration 1 (i.e., the non-reference LTM CU configuration) as an incremental configuration to enhance the reference LTM CU configuration. Similarly, CU 172 may generate some or all of LTM CU configurations 2, ..., N as incremental configurations to enhance the reference LTM CU configuration. Alternatively, in RRC reconfiguration message 316 or the first container, CU 172 includes the reference LTM CU configuration but not the non-reference LTM CU configuration. In some implementations, CU 172 includes the reference LTM CU configuration and / or the reference LTM DU configuration in an additional container (e.g., the reference LTM DU configuration), and includes the additional container in RRC reconfiguration message 316.

[0074] In some implementations, the reference LTM CU configuration differs from the service CU configuration. In some implementations, a portion of the reference LTM CU configuration is identical to a portion of the service CU configuration, while the remainder of the reference LTM CU configuration differs from the remainder of the service CU configuration. In still other implementations, the reference LTM CU configuration is identical to the service LTM CU configuration.

[0075] In some implementations, CU 172 includes the first LTM ID (hereinafter referred to as ID 1) used to identify LTM DU configuration 1 or element 1 in the RRC reconfiguration message. In some implementations, CU 172 includes ID 1 in the first container or element 1. In some implementations, CU 172 assigns ID 1.

[0076] In some implementations, CU 172 may send ID 1 to DU 174, and DU 174 may associate ID 1 with LTM DU configuration 1 and / or cell ID 1. In some implementations, CU 172 may include ID 1 in a first CU-DU message. In other implementations, after receiving the first DU-CU message, CU 172 sends a third CU-DU message including ID 1 to DU 174, instead of including ID 1 in the first CU-DU message. In some implementations, in the third CU-DU message, CU 172 may include LTM DU configuration 1 and ID 1 and indicate the association between ID 1 and LTM DU configuration 1. Therefore, DU 174 may directly associate ID 1 with LTM DU configuration 1. In other implementations, in the third CU-DU message, CU 172 may include cell ID 1 and ID 1 (i.e., the first LTM ID) and indicate the association between cell ID 1 and ID 1. Therefore, DU 174 can associate ID 1 with LTM DU configuration 1 based on the association between cell ID 1 and ID 1, and the association between cell ID 1 and LTM DU configuration 1. In other implementations, in the third CU to DU message, CU 172 may include LTM DU configuration 1, cell ID 1 and / or ID 1, and indicate the association between ID 1, LTM DU configuration 1 and / or cell ID 1. In some implementations, DU 174 may send a third DU to CU message 314 in response to the third CU to DU message. In some implementations, the third CU to DU message and the third DU to CU message are... UE Context Modification Request information and UE context modification response message In some implementations, CU 172 may include ID 1, Cell ID 1, and / or LTMDU Configuration 1 in the second CU-DU message, as described above. Therefore, the third CU-DU message can be omitted. In some implementations, the third DU-CU message is... UE context modification request message In such cases, CU 172 responds to UE top and bottom Document modification requirements message Send to DU 174 UE context modification confirmation message .

[0077] In some implementations, events 312 (optional) and / or 314 (optional) are... Figure 3 This is collectively referred to as the LTM ID allocation process 392.

[0078] If CU 172 includes ID 1 in the first CU to DU message, DU 174 may include ID 1 in LTM DU configuration 1, the first container, or element 1. Alternatively, DU 174 may not include ID 1 in LTM DU configuration 1, the first container, and / or element 1.

[0079] In some implementations, CU 172 includes the referenced LTM DU configuration in the first container. For example, CU 172 includes the referenced LTM DU configuration in a field of the first container that is different from the field of the first container that includes LTM DU configuration 1. In other implementations, CU 172 includes the referenced LTM DU configuration in the RRC reconfiguration message 316 and outside the first container. For example, CU 172 generates a third container (e.g., field / IE) to include the first container and the referenced LTM DU configuration, and includes the third container in the RRC reconfiguration message 316. In yet another implementation, DU 174 includes the referenced LTM DU configuration in the first container. For example, DU 174 includes the referenced LTM DU configuration in a field of the first container that is different from the field of the first container that includes LTM DU configuration 1. In yet another implementation, DU 174 generates a fourth container (e.g., field / IE) to include the first container and the referenced LTM DU configuration, and includes the fourth container in the first DU to CU message 310. In such cases, CU 172 includes the fourth container in RRC reconfiguration message 316. Alternatively, CU 172 retrieves reference LTM DU configuration and LTM DU configuration 1 from the fourth container and includes reference LTM DU configuration and LTM DU configuration 1, as described above.

[0080] In some implementations, neither CU 172 nor DU 174 is assigned an ID to identify the reference LTM DU configuration.

[0081] In some implementations, LTM DU configuration 1 includes multiple configuration parameters for UE 102 to communicate with DU 174 on the first cell. In some implementations, these multiple configuration parameters include physical layer configuration parameters (e.g., PhysicalCellGroupConfig IE), MAC layer configuration parameters (e.g., MAC-CellGroupConfig IE) and / or RLC configuration parameters (e.g., RLC-BearerConfig IE). In some further implementations, these multiple configuration parameters include special cell configurations (e.g., SpCellConfig IE) and / or one or more SCell configurations (e.g., SCellConfig(IE). In some implementations, LTM DU configuration 1 is defined in 3GPP TS 38.331. CellGroupConfig IE. In other implementations, LTM DU configuration 1 includes... CellGroupConfig Configuration parameters in Internet Explorer.

[0082] In some implementations, LTM CU Configuration 1 includes PDCP configuration parameters, measurement configuration parameters, and / or radio bearer configuration parameters. In some implementations, LTM CU Configuration 1 includes those defined in 3GPP TS 38.331. MeasConfig IE and / or RadioBearerConfig IE, or including MeasConfig IE and / or RadioBearerConfig Configuration parameters in IE. In some implementations, LTM DU configuration 1 includes L1 measurement configuration 1 (e.g., CSI-MeasConfig The LTM CU configuration 1 includes an L1 measurement configuration and / or at least one TCI status configuration. In other implementations, the L1 measurement configuration includes at least one Reference Signal (RS) resource configuration 1 and / or at least one Reporting configuration 1. In some implementations, the RS resource configuration 1 configures one or more RSs or one or more RS resources associated with cell 1. RSs include SSBs and / or CSI-RSs. RS resources include SSB resources and / or CSI-RS resources. In some implementations, each of the RS resource configurations 1 includes an RS resource configuration ID. In some implementations, the RS resource configuration 1 is... CSI-ResourceConfig IE (and similar). In some implementations, Report Configuration 1 configures one or more UL resources (e.g., PUCCH or PUSCH resources) for UE 102 on cell 1 to transmit measurement results. In some implementations, each of Report Configuration 1 includes one or more RS resource configuration IDs that identify one or more RS resource configurations included in RS Resource Configuration 1. In some implementations, each of TCI State Configuration 1 configures a TCI state that associates one or two DL RSs with the corresponding Quasi-Co-located (QCL) type. The DL RS is associated with cell 1.

[0083] In some implementations, DU 174 includes L1 measurement configuration 1 and / or TCI state configuration 1 in the service DU configuration 1 (e.g., a non-LTM DU configuration). In some implementations, DU 174 includes the service DU configuration in the first DU-to-CU message. In other implementations, DU 174 sends an additional DU-to-CU message including the service DU configuration to CU 172. In some implementations, the additional DU-to-CU message is... UE context modification requirements In some implementations, CU 172 includes service DU configuration 1 in RRC reconfiguration messages 316 and 318. In other implementations, CU 172 sends another RRC reconfiguration message including service DU configuration to UE 102 via DU 174.

[0084] In some implementations, DU 174 includes the random access configuration in LTM DU configuration 1. In other implementations, DU 174 does not include the random access configuration in LTM DU configuration 1. In some implementations, if cell 124A and the first cell are not synchronized, DU 174 determines to include the random access configuration in LTM DU configuration 1. Otherwise, if cell 124A and the first cell are synchronized, DU 174 determines not to include the random access configuration in LTM DU configuration 1. In other implementations, if DU 174 determines that UE 102 has not yet synchronized with the first cell in the UL, DU 174 determines to include the random access configuration in LTM DU configuration 1. Otherwise, if DU 174 determines that UE 102 is already synchronized with the first cell in the UL, DU 174 determines not to include the random access configuration in LTM DU configuration 1. If LTM DU configuration 1 includes a random access configuration, then UE 102 performs a random access procedure in event 332 according to the random access configuration, as described below. Otherwise, if LTM DU configuration 1 does not include a random access configuration or instructs UE 102 to skip the random access procedure in LTM, then UE 102 skips or avoids performing the random access procedure in event 332 in response to LTM DU configuration 1 excluding the random access configuration.

[0085] In some implementations, regardless of whether cell 124A and the first cell are synchronized, DU 174 includes the random access configuration parameters in LTM DU configuration 1 and / or reference LTM DU configuration. UE 102 executes the random access procedure in event 332 according to the random access configuration parameters, as described below. In some implementations, the random access configuration parameters configure physical random access channel (PRACH) resources, the association between SSB and PRACH resources, and / or one or more PRACH timings.

[0086] In some implementations, if cell 124A and the first cell are synchronized, DU 174 determines to include a first indication in LTM DU configuration 1, which configures UE 102 not to perform a random access procedure on the first cell. Otherwise, if cell 124A and the first cell are not synchronized, DU 174 determines not to include the first indication in LTM DU configuration 1. In other implementations, if DU 174 determines that UE 102 is already synchronized with the first cell in the UL, DU 174 determines to include the first indication in LTM DU configuration 1. Otherwise, if DU 174 determines that UE 102 is not yet synchronized with the first cell in the UL, DU 174 determines not to include the first indication in LTM DU configuration 1. If LTM DU configuration 1 includes the first indication, UE 102 skips or avoids performing the random access procedure of event 332 according to or in response to the first indication. Otherwise, if LTMDU configuration 1 excludes the first indication, then in response to LTMDU configuration 1 not including the first indication, UE 102 performs a random access procedure in event 332 according to the random access configuration, as described below.

[0087] In some implementations, DU 174 will perform reconfiguration with sync configuration (e.g., ReconfigurationWithSync IE) is included in LTM DU configuration 1 or special cell configuration. In other implementations, DU 174 does not include reconfiguration configuration with synchronization (e.g., ReconfigurationWithSync The IE (Internal Access Configuration) is included in LTM DU Configuration 1 or a special cell configuration. In some implementations, DU 174 includes LTM cell handover information in the first LTM DU Configuration 1. In some implementations, DU 174 includes random access configuration (parameters) in the LTM cell handover information (e.g., ltm-CellSwitchInfo field or LTM- CellSwitchInfoIn some implementations, if cell 124A and the first cell are not synchronized, DU 174 determines to include the reconfiguration configuration with synchronization in LTM DU configuration 1. Otherwise, if cell 124A and the first cell are synchronized, DU 174 determines not to include the reconfiguration configuration with synchronization in LTM DU configuration 1. In other implementations, if DU 174 determines that UE 102 and the first cell are not yet synchronized in UL, DU 174 determines to include the reconfiguration configuration with synchronization in LTM DU configuration 1. Otherwise, if DU 174 determines that UE 102 and the first cell are already synchronized in UL, DU 174 determines not to include the reconfiguration configuration with synchronization in LTM DU configuration 1. In some implementations, if LTM DU configuration 1 includes the reconfiguration configuration with synchronization, UE 102 performs a random access procedure in event 332 in response to or based on the reconfiguration configuration with synchronization, as described below. Otherwise, if LTM DU configuration 1 does not include a reconfiguration with a synchronization configuration, UE 102 skips or avoids performing the random access procedure of event 332. In some implementations, DU 174 includes the cell ID (i.e., cell ID 1) of cell 1 (i.e., the first cell) in LTM DU configuration 1. In one implementation, cell ID 1 may be a PCI. In another implementation, cell ID 1 is a CGI. In some implementations, cell ID 1 included in LTM DU configuration 1 is a PCI, while cell ID 1 included in the first CU to DU message is a CGI. In some additional implementations, LTM DU configuration 1 includes cell index 1 indexed to cell ID 1 or the first cell. Cell index 1 is not a cell ID. The cell index occupies fewer bits than the cell ID. In some implementations, CU 172 sets cell index 1 to a value and includes cell index 1 in the first CU to DU message of event 308.

[0088] In some implementations, upon receiving one or more of the at least one measurement report of event 304 (e.g., in response to this), the first BS 104 (i.e., CU 172 or DU 174) determines an additional cell (i.e., cell 2, ..., N) to prepare for LTM for UE 102. In one implementation example, the first BS 104 determines the additional cell to prepare for LTM for UE 102 because the at least one measurement report indicates that the additional cell can be used by the first BS 104 to communicate with UE 102. The additional cell may include cell 124C and / or cells other than cells 124A, 124B, and 124C. In some implementations, if an L3 measurement report indicates that the signal strength and / or quality of a particular cell in the additional cells is higher than a corresponding predetermined threshold and / or better than cell 124A, then CU 172 determines to prepare that particular cell for LTM for UE 102. In other implementations, if the L1 measurement report indicates that the signal strength and / or quality of a particular cell in the additional cells is higher than a first predetermined threshold and / or better than cell 124A, then DU 174 determines to prepare that particular cell for LTM for UE 102. In one implementation, the corresponding predetermined threshold for the additional cell may be different from the first predetermined threshold. In another implementation, the corresponding predetermined threshold for the additional cell may be the same as the first predetermined threshold. In some implementations, the corresponding predetermined threshold for the additional cell may be the same or different. Alternatively, the first BS 104 determines to prepare the additional cell for UE 102 regardless of whether a measurement report is received from UE 102.

[0089] When CU 172 determines that an additional cell is to be prepared, CU 172 initiates and executes at least one additional LTM preparation procedure (LTM preparation procedure) with DU 174 to prepare the additional cell for LTM, wherein each of the LTM preparation procedures is similar to procedure 390. When DU 174 determines that an additional cell is to be prepared, DU 174 initiates and executes at least one additional LTM preparation procedure (LTM preparation procedure) with CU 172 to prepare the additional cell for LTM, wherein each of the LTM preparation procedures is similar to procedure 390.

[0090] In some implementations, CU 172 and DU 174 perform LTM preparation procedures 2, ..., N similar to procedure 390 to prepare cells 2, ..., N, respectively. CU 172 may include cell IDs 2, ..., N in CU-DU messages 2, ..., N in LTM preparation procedures 2, ..., N, similar to the first CU-DU message. In LTM preparation procedures 2, ..., N, DU 174 generates LTM DU configurations 2, ..., N for cells 2, ..., N, and includes LTM DU configurations 2, ..., N in DU-CU messages 2, ..., N, as described for LTM DU configuration 1. Upon receiving CU-DU messages 2, ..., N, DU-CU messages 2, ..., N respond to CU-DU messages 2, ..., N, respectively. "N" is an integer greater than one. For example, "N" can be 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16. In another example, the maximum number of "N" is 4, 8, 16, or 32. The example and implementation of LTM DU configuration 1 can be applied to LTM DU configurations 2, ..., N.

[0091] In other implementations, CU 172 and DU 174 perform a single LTM preparation procedure (i.e., LTM preparation procedure 390) to prepare cells 1, 2, ..., N. In this case, DU 174 includes LTM DU configurations 1, 2, ..., N for cells 1, 2, ..., N respectively in the first DU to CU message. In the first DU to CU message, DU 174 may include cell IDs 1, 2, ..., N associated with LTM DU configurations 1, 2, ..., N respectively to indicate that LTM DU configurations 1, 2, ..., N are configured for cell IDs 1, 2, ..., N respectively. When CU 172 determines to perform LTM preparation procedure 390, CU 172 includes cell IDs 1, 2, ..., N in the first CU to DU message to request DU 174 to prepare cells 1, 2, ..., N for LTM respectively.

[0092] After receiving LTM DU configurations 2, ..., N from DU 174, CU 172 may include LTM DU configurations 2, ..., N in a first container. In some implementations, CU 172 may include LTM DU configurations 2, ..., N in elements 2, ..., N respectively, and include elements 2, ..., N in the first container. In some implementations, CU 172 may include the LTM IDs (i.e., ID 2, ..., N) used to identify LTM DU configurations 2, ..., N in the RRC reconfiguration message. In some implementations, CU 172 may include ID 2, ..., N in the first container. For example, CU 172 may include ID 2, ..., N and LTM DU configurations 2, ..., N in elements 2, ..., N in a first add or modify list.

[0093] In some implementations, CU 172 assigns IDs 2, ..., N to LTM DU configurations 2, ..., N respectively. In other implementations, CU 172 receives IDs 2, ..., N from DU 174 in the first DU to CU message of process 390. In yet another implementation, CU 172 receives IDs 2, ..., N from DU 174 in the DU to CU messages 2, ..., N of LTM preparation processes 2, ..., N respectively.

[0094] In some implementations, CU 172 and DU 174 may perform an LTM ID allocation procedure for each of LTM DU configurations 2, ..., N, similar to procedure 392. In other implementations, CU 172 may include IDs 2, ..., N and LTM DU configurations 2, ..., N in a third CU-DU message and indicate the association between IDs 2, ..., N and LTM DU configurations 2, ..., N respectively. Therefore, DU 174 may associate LTM DU configurations 2, ..., N with IDs 2, ..., N respectively. In yet another implementation, CU 172 may include cell IDs 2, ..., N and IDs 2, ..., N in a third CU-DU message and indicate the association between cell IDs 2, ..., N and IDs 2, ..., N respectively. Therefore, DU 174 can associate LTM DU configurations 2, ..., N with ID 2, ..., N respectively, based on the association between cell IDs 2, ..., N and ID 2, ..., N, and the association between cell IDs 2, ..., N and LTM DU configurations 2, ..., N. In other implementations, CU 172 can include IDs 2, ..., N, cell IDs 2, ..., N, and / or LTM DU configurations 2, ..., N in the second CU to DU message, as described above. Therefore, the third CU to DU message can be omitted. In yet another implementation, CU 172 can include IDs 2, ..., N in the first CU to DU message and indicate that IDs 2, ..., N are associated with cell IDs 2, ..., N respectively. In one implementation, DU 174 includes IDs 2, ..., N in LTM DU configurations 2, ..., N. Therefore, CU 172 does not include ID 2, ..., N in the RRC reconfiguration message, the first container, and / or elements 2, ..., N.

[0095] In some alternative implementations, DU 174 assigns IDs 2, ..., N. In some implementations, DU 174 includes IDs 2, ..., N in the first DU to CU message of process 390. In yet another implementation, DU 174 includes IDs 2, ..., N in DU to CU messages 2, ..., N of LTM preparation process 2, ..., N. CU 172 may include IDs 2, ..., N in the RRC reconfiguration message. In other implementations, DU 174 includes IDs 2, ..., N in LTMDU configuration 2, ..., N. Therefore, CU 172 does not include the ID (e.g., LTM ID) identifying each of LTM DU configurations 2, ..., N in the RRC reconfiguration message, the first container, and / or element 1.

[0096] In some alternative implementations, CU 172 may generate a second container including LTM DU configuration 2, ..., N or element 2, ..., N, instead of using the first container. CU 172 then sends an additional RRC reconfiguration message including the second container to UE 102 via DU 174, similar to events 316 and 318. In response, UE 102 sends an additional RRC reconfiguration complete message to CU 172 via DU 174, similar to events 320 and 322. In some implementations, the second container may be a second add or modify list (e.g., ...). ltm-ConfigToAddModList Fields LTM-ConfigToAddModList IE ltm-CandidateConfigToAddModList field or LTM-CandidateConfigToAddModList IE), and each of elements 2, ..., N can be used to add or modify IE (e.g., ltm-ConfigToAddMod Fields LTM-ConfigToAddMod IE ltm-CandidateConfigToAddMod field or LTM- CandidateConfigToAddMod When UE 102 receives the second add or modify list, UE 102 may store the second add or modify list together with the first add or modify list (e.g., in a variable in its random access memory (RAM)).

[0097] In some implementations, DU 174 includes cell IDs 2, ..., N in LTM DU configurations 2, ..., N to identify cells 2, ..., N. In one implementation, each of cell IDs 2, ..., N is a PCI. In some other implementations, LTM DU configurations 2, ..., N include cell indices 2, ..., N indexed for cell IDs 2, ..., N or cells 2, ..., N respectively. When CU 172 prepares cells 2, ..., N for LTM in process 390, CU 172 may set cell indices 2, ..., N to different values ​​and include cell indices 2, ..., N in the first CU-to-CU-to-DU message of event 308. When CU 172 prepares cells 2, ..., N in an additional LTM preparation process, CU 172 may set cell indices 2, ..., N to different values ​​and include cell indices 2, ..., N in the CU-to-DU message of the additional LTM preparation process. CU 172 sets cell indices 1, ..., N to different values. In some implementations, the cell IDs 1, ..., N in the LTM DU configuration 1, ..., N are different from the cell IDs 1, ..., N in the CU to DU message described above.

[0098] In some implementations, each of LTM DU configurations 1, ..., N includes physical configuration parameters, MAC configuration parameters, RLC configuration parameters, and / or L1 measurement configuration. In some implementations, each of LTM DU configurations 1, ..., N may be as defined in 3GPP TS 38.331. CellGroupConfig IE. In other implementations, each of the LTM DU configurations 1, ..., N includes as defined in 3GPP TS 38.331. CellGroupConfig The configuration parameters included in IE. In some other implementations, multiple configuration parameters in each LTM DU configuration include specific cell-specific configurations (e.g., SpCellConfig IE) and / or one or more SCell configurations (e.g., SCellConfig (IE). In some implementations, the LTM DU configuration 1, ..., N is defined in 3GPP TS 38.331. CellGroupConfig IE. In other implementations, LTM DU configuration 1, ..., N includes CellGroupConfig Configuration parameters in Internet Explorer.

[0099] In some implementations, CU 172 may include one or more additional LTM CU configurations in at least one of elements 2, ..., N, the first container, or the second container. Each of the additional LTM CU configurations is associated with a specific LTM DU configuration in LTM DU configurations 2, ..., N. Examples and implementations of the additional LTM CU configurations are similar to those of LTM CU configuration 1.

[0100] In some implementations, CU 172 determines to release LTM DU configuration M (or element M in element 1, ..., M) from LTM DU configurations 1, ..., N, where 1 ≤ M ≤ N. In response to this determination, CU 172 sends an RRC reconfiguration message to UE 102 via DU 174 to instruct UE 102 to release LTM DU configuration M or element M. In one implementation, CU 172 generates a release list including an ID (i.e., LTM ID) M for releasing LTM DU configuration M or element M, and includes this release list in the RRC reconfiguration message. In response to the RRC reconfiguration message, UE 102 releases LTM DU configuration M or element M and sends an RRC reconfiguration complete message to CU 172 via DU 174. In response to this determination, CU 172 sends a CU-DU message to DU 174 to instruct DU 174 to release LTM DU configuration M. To instruct DU 174 to release the LTM DU configuration M, CU 172 may include the cell ID M or ID (i.e., the LTM ID) M in the release instruction (e.g., a field or IE) in the CU-DU message. In response, DU 174 releases the LTM DU configuration M and sends a DU-CU message to CU 172. In some implementations, the CU-DU message and the DU-CU message are respectively a UE context modification request message and a UE context modification response message.

[0101] In other implementations, DU 174 determines to release LTM DU configuration K. In response to this determination, DU 174 sends a DU-to-CU message to CU 172 to release LTM DU configuration K. To indicate that LTM DU configuration K is released, DU 174 may include the cell ID K or ID (i.e., LTM ID) K in the release indication (e.g., a field or IE) in the DU-to-CU message, where 1 ≤ K ≤ N. Upon receiving the DU-to-CU message (e.g., in response to this), CU 172 generates a release list including the ID (i.e., LTM ID) K to release LTM DU configuration K or element K, and sends an RRC reconfiguration message including the release list to UE 102 via DU 174. In response, UE 102 releases LTM DU configuration K or element K and sends an RRC reconfiguration complete message to UE 102 via DU 174. CU 172 may send a CU-to-DU message to DU 174 in response to the DU-to-CU message. In some implementations, the DU to CU message and the CU to DU message are respectively the UE context modification request message and the UE context modification confirmation message.

[0102] After receiving an RRC reconfiguration in event 318 or sending an RRC reconfiguration completion message in event 320, UE 102 sends at least one measurement report (324) to DU 174, similar to event 304. In some implementations, DU 174 may send a DU-CU message (326) including at least one measurement report to CU 172, similar to event 306. In other implementations, DU 174 does not send at least one measurement report to CU 172. In some implementations, at least one measurement report in event 324 includes an L1 measurement report or an L3 measurement report, as described for event 304. In some implementations, UE 102 sends at least one measurement report (324) to DU 174 on PUCCH and / or PUSCH, similar to event 304. In other implementations, UE 102 sends at least one MAC CE (324) including at least one measurement report to DU 174, similar to event 304. In some implementations, UE 102 does not send L1 measurement reports to DU 174 in the format of RRC messages.

[0103] In some implementations, UE 102 sends at least one measurement report (324) to DU 174 according to at least one measurement configuration. This at least one measurement configuration configures UE 102 to perform measurements and report measurement results. CU 172 sends at least one measurement configuration to UE 102 via DU 174. For example, in events 302 and / or 316 and / or after events 306 or 316, CU 172 may send one or more RRC messages (e.g., including at least one measurement configuration) to UE 102 via DU 174. RRCReconfiguration (Message). The one or more RRC messages may or may not include the RRC reconfiguration message of event 316. According to the at least one measurement configuration, UE 102 performs measurements on one or more reference signals. The one or more reference signals may include one or more SSBs and / or one or more CSI-RSs. UE 102 obtains the at least one L1 measurement result and / or at least one L3 measurement result from the measurements and includes the at least one L1 measurement result and / or at least one L3 measurement result in the at least one measurement report of event 324. DU 174 transmits the one or more reference signals on cell 124A, cell 1, and / or cell 2, ..., N. The one or more reference signals may be CSI-RS or SSB.

[0104] In some implementations, the at least one measurement configuration includes an L3 measurement configuration (e.g., MeasConfig(IE), as described for event 304. In other implementations, the at least one measurement configuration includes or is an L1 measurement configuration, as described above. In yet another implementation, the L1 measurement configuration may be as defined in 3GPP TS 38.331. CSI- MeasConfig IE. L1 measurement configuration may include RS resource configuration and / or reporting configuration. UE 102 sends a 324 L1 measurement report to DU 174 on a UL resource (e.g., a PUCCH resource or a PUSCH resource) according to the reporting configuration. DU 174 receives the L1 measurement report on a UL resource according to the reporting configuration. In some implementations, the reporting configuration is... CSI-ReportConfig An IE or similar. In other implementations, each of the report configurations is a new RRC IE. In some implementations, each of the report configurations configures periodic reporting and / or event-triggered reporting of L1 measurement results.

[0105] In some implementations, the L1 measurement report is a CSI report. In other implementations, the L1 measurement report is a MACCE. In some implementations, each in the measurement report includes one or more RS resource indicators and / or one or more quantized measurement values. UE 102 performs measurements on RS or RS resources according to RS resource configuration and / or reporting configuration, and obtains quantized measurement values ​​from the measurements. In some implementations, the RS resource indicator instructs UE 102 to perform measurements on RS or RS resources or to obtain quantized measurement values. In some implementations, the RS resource indicator includes one or more SSB resource indicators (SSBRI) and / or one or more CSI-RS resource indicators (CRI). Quantized measurement values ​​may include one or more L1-RSRP values ​​and / or one or more L1-SINR values.

[0106] In other implementations, the at least one measurement configuration includes a new type of measurement configuration (e.g., an LTM measurement configuration). The new type of measurement configuration may be newly defined in the 3GPP specification. In some implementations, the new type of measurement configuration includes a reference signal resource configuration that configures the resources in which DU 174 transmits reference signals. For example, the reference signal resource configuration includes CSI-RS and / or SSB. In one implementation, the reference signal resource configuration is... CSI-ResourceConfigIE. In another implementation, the new type of measurement configuration includes a measurement report configuration, as described above. UE 102 sends a measurement report to DU 174 on the PUCCH or MAC CE according to the measurement report configuration. DU 174 receives the measurement report on the PUCCH or MAC CE according to the measurement report configuration. In this case, the measurement report can be an L1 measurement report or a new type of measurement report (e.g., an LTM measurement report). In some implementations, the new type of measurement configuration includes configuration parameters newly defined in the 3GPP specifications.

[0107] Upon receiving a measurement report in event 324 (e.g., in response to this), DU 174 generates a first LTM command to activate LTM DU configuration 1 (i.e., the first LTM command instructs UE 102 to apply LTM DU configuration 1 or perform a serving cell change to cell 1). DU 174 then sends the first LTM command to UE 102 at 330. In some implementations, DU 174 sends the first LTM command to UE 102 on cell 124A. In other implementations, DU 174 sends the first LTM command to UE 102 on cell 124D. In some implementations, DU 174 may include ID 1 in the first LTM command to indicate LTM DU configuration 1 or element 1, and UE 102 determines (e.g., identifies) LTM DU configuration 1 or element 1 based on ID 1.

[0108] In other implementations, DU 174 may include cell index 1, which is indexed to cell ID 1, in the first LTM command. UE 102 determines (e.g., identifies) LTM DU configuration 1 or element 1 based on cell index 1. Before receiving the first LTM command, UE 102 retrieves cell index 1 from LTM DU configuration 1 or element 1 and establishes association 1 between cell index 1 and LTM DU configuration 1 or element 1. In other words, before receiving the first LTM command, UE 102 decodes LTM DU configuration 1 or element 1 to obtain cell index 1. Therefore, UE 102 identifies LTM DU configuration 1 or element 1 based on cell index 1 and association 1. Before receiving the first LTM command, UE 102 retrieves cell indices 2, ..., N from LTM DU configurations or elements 2, ..., N, and establishes associations 2, ..., N between cell indices 2, ..., N and LTM DU configurations or elements 2, ..., N, respectively. In other words, before receiving the first LTM command, UE 102 decodes the LTM DU configuration or elements 2, ..., N to obtain cell indices 2, ..., N.

[0109] In other implementations, DU 174 includes cell ID 1 in the first LTM command, where cell ID 1 identifies cell 1. In some implementations, the cell ID 1 included in the first LTM command is the same as the cell ID 1 included in the first CU to DU message. In other implementations, DU 174 determines the cell ID 1 (e.g., PCI) included in the first LTM command from the cell ID 1 (e.g., CGI) received in the first CU to DU message. UE 102 determines (e.g., identifies) LTM DU configuration 1 or element 1 based on cell ID 1. Before receiving the first LTM command, UE 102 retrieves cell ID 1 from LTM DU configuration 1 or element 1 and establishes an association 1 between cell ID 1 and LTM DU configuration 1 or element 1. In other words, before receiving the first LTM command, UE 102 decodes LTM DU configuration 1 or element 1 to obtain cell ID 1. Therefore, UE 102 identifies LTM DU configuration 1 or element 1 based on cell ID 1 (received in the first LTM command) and association 1. Before receiving the first LTM command, UE 102 retrieves cell IDs 2, ..., N from LTM DU configurations or elements 2, ..., N, and establishes associations 2, ..., N between cell IDs 2, ..., N and LTM DU configurations or elements 2, ..., N respectively. In other words, before receiving the first LTM command, UE 102 decodes LTM DU configurations or elements 2, ..., N to obtain cell IDs 2, ..., N. In some implementations, DU 174 has a mapping table for storing mappings between PCI1, ..., N and CGI1, ..., N for cells 1, ..., N respectively.

[0110] In other implementations, DU 174 may include a bitmap instead of ID 1 or cell index 1 in the first LTM command to activate LTM DU configuration 1. The number of bits in the bitmap is greater than or equal to "N". In one implementation, bits 1, ..., N correspond to the following: cell index 1, ..., N; ID 1, ..., N; LTM DU configuration 1, ..., N; or element 1, ..., N, and DU 174 sets the corresponding bit (e.g., bit 1) in the bitmap to a first value to indicate cell index 1, ID 1, LTM DU configuration 1, or element 1. Therefore, UE 102 can determine cell index 1, ID 1, LTM DU configuration 1, or element 1 based on bit 1 in the bitmap set to a first value. In another implementation, bits 0, ..., N-1 correspond to the following: cell index 1, ..., N; ID 1, ..., N; LTM DU configuration 1, ..., N; or element 1, ..., N, respectively, and DU174 sets the corresponding bit (e.g., bit 0) in the bitmap to a first value to indicate cell index 1, ID 1, LTM DU configuration 1, or element 1. Therefore, UE 102 can determine cell index 1, ID 1, LTM DU configuration 1, or element 1 based on bit 0 set to the first value in the bitmap. In this implementation, DU 174 sets the remaining bits in the bitmap to a second value to indicate that the remainder of LTM DU configuration 1, ..., N is not activated. In some implementations, the first value is one, and the second value is zero. In other implementations, the first value is zero, and the second value is one. Generally, if DU 174 determines that LTM DU configuration is activated for UE 102... L Or change the service area to a community L Then DU 174 can display the corresponding bit in the bitmap (e.g., bit 174). L or position L-1 ) is set to the first value and the remaining bits are set to the second value, where 1≤L≤N In some implementations, the DU 174 sets at most one bit in the bitmap to the first value.

[0111] After determining or identifying LTM DU configuration 1 or element 1, UE 102 then applies LTM DU configuration 1 and / or LTM CU configuration after receiving the first LTM command (e.g., in response to this).

[0112] In some implementations, at least one measurement report of event 324 (e.g., an L1 measurement report or a new type measurement report) includes at least one measurement result for the first cell, the TRP of the first cell, or a reference signal transmitted on the first cell. The reference signal may be CSI-RS or SSB. DU 174 determines to activate LTM DU Configuration 1 or send a first LTM command based on at least one measurement result. In some implementations, DU 174 determines to activate LTM DU Configuration 1 because at least one measurement result is higher than a second predetermined threshold, when at least one measurement result is higher than the second predetermined threshold, or if at least one measurement result is higher than the second predetermined threshold. In some implementations, at least one measurement result includes an L1-RSRP value, an L1-RSRQ value, and / or an L1-SINR value. In other implementations, at least one measurement result includes the RSRP value, RSRQ value, and / or SINR value of a new type measurement report. In some implementations, the second predetermined threshold is different from the first predetermined threshold. In one implementation, the second predetermined threshold is greater than the first predetermined threshold. In this scenario, at least one measurement indicates that the first cell is suitable for communication with UE 102. In another implementation, the second predetermined threshold is equal to the first predetermined threshold. In this case, at least one measurement indicates that the first cell consistently exceeds either the second or the first predetermined threshold. This indicates that the first cell is suitable for communication with UE 102. Therefore, for UE 102, DU 174 determines to activate LTM DU configuration 1 in response to the first cell's signal strength or quality exceeding the second predetermined threshold.

[0113] In some implementations, at least one measurement report (e.g., an L3 measurement report) for events 324 and 326 includes at least one measurement result for the first cell. CU 172 determines to activate LTM DU configuration 1 or send a first LTM command because at least one measurement result indicates that the signal strength or quality of the first cell is higher than a second predetermined threshold. The second predetermined threshold is different from the first predetermined threshold. In one implementation, the second predetermined threshold is greater than the first predetermined threshold. In this implementation, at least one measurement report for event 326 indicates that the signal strength or quality of the first cell is suitable for communication with UE 102. In another implementation, the second predetermined threshold is equal to the first predetermined threshold. In this implementation, at least one measurement report for event 326 indicates that the signal strength or quality of the first cell is consistently higher than either the second or first predetermined threshold. This also indicates that the first cell is suitable for communication with UE 102. Therefore, CU 172 determines to activate LTM DU configuration 1 in response to the signal strength or quality of the first cell being higher than the second predetermined threshold. In response to this determination, CU 172 sends a fourth CU-DU message (328) to DU 174 to activate LTM DU configuration 1 or trigger a serving cell change for UE 102 to cell 1. In some implementations, CU 172 includes ID 1 in the fourth CU-DU message. In other implementations, CU 172 includes cell index 1 in the fourth CU-DU message. In response to the fourth CU-DU message, DU 174 sends a first LTM command (330) to UE 102 and optionally sends a fourth DU-CU message to CU 172. In some implementations, CU 172 includes cell index 1 in the fourth CU-DU message. Therefore, DU 174 can determine the activation of LTM DU configuration 1 based on cell index 1. In other implementations, CU 172 may include cell ID 1 in the fourth CU-DU message. Therefore, DU 174 determines the activation of LTM DU configuration 1 based on cell ID 1. In other implementations, CU 172 can include ID 1 in the fourth CU to DU message. Therefore, DU 174 can determine the activation of LTM DU configuration 1 based on ID 1. In some implementations, the fourth CU to DU message and the fourth DU to CU message are respectively... UE Context Modification Request Messages and UE context modification response In other implementations, the fourth CU to DU message and / or the fourth DU to CU message are new interface messages, such as the F1 Application Protocol (F1AP) message defined in 3GPP TS 38.473.

[0114] When LTM DU configuration 1 is activated or the first LTM command 330 is sent, or in response to this, DU 174 may send a DU-to-CU message 329 to CU 172 indicating that LTM is being performed. In some implementations, the DU-to-CU message is an LTM cell change notification message. In some implementations, DU 174 includes cell ID 1 or ID 1 (i.e., LTM ID) in the DU-to-CU message 329 to indicate that DU 174 will activate LTM DU configuration 1 or trigger a fast serving cell change (i.e., an LTM serving cell change). DU may send the DU-to-CU message 329 to CU 172 before or after sending the LTM command 330.

[0115] In some implementations, the first LTM command is the MAC CE included in the MAC PDU received by UE 102 from DU 174 in event 330. The MAC CE may be a new MAC CE defined in 3GPP TS 38.321. In one implementation, DU 174 includes a subheader identifying the new MAC CE in the MAC PDU, and UE 102 identifies the new MAC CE in the MAC PDU based on this subheader. The subheader may include a logical channel ID or an extended logical channel ID defined in the 3GPP specification to identify the new MAC CE. For example, the logical channel ID or extended logical channel ID is newly defined, for example, in 3GPP TS 38.321. In other implementations, the first LTM command is the DCI received by UE 102 on the PDCCH from DU 174 in event 330. DU 174 generates a Cyclic Redundancy Check (CRC) for the DCI, scrambles the CRC using the first C-RNTI of UE 102, and transmits the DCI and the scrambled CRC on the PDCCH in event 330. In one implementation, the DCI format can be an existing DCI format defined in the 3GPP specification (e.g., 38.212). In another implementation example, the DCI format can be a new DCI format defined in the 3GPP specification (e.g., 3GPP TS 38.212).

[0116] In some implementations, DU 174 does not perform security protection (e.g., integrity protection and / or encryption) on the first LTM command. This speeds up the processing of the first LTM command in UE 102 because UE 102 does not perform security checks (e.g., decryption and / or integrity checks) on the first LTM command.

[0117] In some implementations, after receiving the first LTM command, UE 102 may send a 331 acknowledgment to DU 174 on cell 124A or cell 124D to indicate that UE 102 has received the first LTM command. In some implementations, this acknowledgment is a HARQ ACK. In other implementations, this acknowledgment is a MAC CE. For example, the MAC CE is an existing MAC CE defined in 3GPP TS 38.321. In another example, the MAC CE is a new MAC CE defined in 3GPP TS 38.321. In yet another implementation, the acknowledgment is a PUCCH transmission.

[0118] In some implementations, CU 172 sends a 316 RRC reconfiguration message in response to an L3 measurement report 306 for the first cell. To configure UE 102 to send an L3 measurement report 306, CU 172 may send a message to UE 102 before event 306 including L3 measurement configuration (e.g., ...). MeasConfig The first RRC reconfiguration message for IE). In some implementations, DU 174 sends a first LTM command 330 in response to an L1 measurement report 324 for the first cell. To configure UE 102 to send an L1 or new type measurement report 324, CU 172 may send a second RRC reconfiguration message to UE 102 including the L1 or new type measurement configuration. In some implementations, the first RRC reconfiguration message and the second RRC reconfiguration message may be the same message (i.e., the same instance). In other implementations, the first RRC reconfiguration message and the second RRC reconfiguration message are different messages. In some implementations, the second RRC reconfiguration message is the RRC reconfiguration message for event 316. In other implementations, the second RRC reconfiguration message is different from the RRC reconfiguration message for event 316.

[0119] Upon receiving the first LTM command (e.g., in response to this), UE 102 accesses the first cell 332. UE 102 identifies LTM DU configuration 1 based on ID 1, cell ID 1, or cell index 1 received in the first LTM command, and applies LTM DU configuration 1 to communicate with DU 174 on the first cell. In some implementations, upon receiving the first LTM command (e.g., in response to this) or after sending acknowledgment 331, UE 102 disconnects from cell 124A. In some implementations, upon receiving 330 to the first LTM command or after sending acknowledgment 331 (e.g., in response to this), UE 102 ceases communication on cell 124A. In some implementations, UE 102 accesses the first cell by performing a random access procedure with DU 174 on the first cell in response to receiving the first LTM command. In other implementations, upon receiving the first LTM command (e.g., in response to this), UE 102 skips the random access procedure and sends a first transmission (e.g., a PUSCH transmission or a PUCCH transmission) to DU 174 on the first cell.

[0120] In some implementations, DU 174 configures UE 102's access to the first cell in LTM DU configuration 1, including whether UE 102 performs a random access procedure. When a first LTM command is received (e.g., a first LTM command), UE 102 determines whether to perform a random access procedure on the first cell according to LTM DU configuration 1. If LTM DU configuration 1 configures UE 102 to perform a random access procedure, then in event 332, UE 102 performs a random access procedure on the first cell to connect to the first cell. For example, LTM DU configuration 1 includes a reconfiguration configuration with synchronization (e.g., ...). ReconfigurationWithSync IE) is configured so that when UE 102 receives an LTM command for the first cell, UE 102 performs a random access procedure. In other implementations, in LTM DU configuration 1, DU 174 configures UE 102 to skip the random access procedure for LTM serving cell change to the first cell. In such cases, after receiving the first LTM command, in event 332, UE 102 skips the random access procedure and sends a first transmission (e.g., a PUSCH transmission or a PUCCH transmission) to DU 174 on the first cell. In some implementations, DU 174 excludes reconfiguration with synchronization in LTM DU configuration 1 to configure UE 102 to skip the random access procedure for LTM serving cell change to the first cell.

[0121] In other implementations, LTM DU configuration 1 includes a reconfiguration configuration with synchronization or a random access configuration. In such cases, DU 174 configures in the LTM command whether UE 102 performs a random access procedure on the first cell. Therefore, UE 102 determines whether to perform a random access procedure on the first cell in event 332 based on the first LTM command. In some implementations, DU 174 includes an indication (e.g., a field) indicating skipping the random access procedure in the first LTM command. In response to this indication or the first LTM command including the indication, UE 102 skips the random access procedure and directly transmits a first transmission (e.g., a PUSCH transmission or a PUCCH transmission) on the first cell to access the first cell. In other implementations, DU 174 excludes this indication in the first LTM command to configure UE 102 to perform a random access procedure. In response to the first LTM command excluding the indication, UE 102 performs a random access procedure on the first cell to access the first cell. In some other implementations, DU 174 includes a timing advance value in the first LTM command to indicate skipping the random access procedure. In response to receiving the timing advance value or a first LTM command including the timing advance value, UE 102 uses the timing advance value to skip the random access procedure and transmits a first transmission on the first cell to access the first cell. In yet another implementation, DU 174 excludes the timing advance value in the first LTM command to configure UE 102 to perform a random access procedure. In response to the first LTM command excluding the timing advance command, UE 102 performs a random access procedure on the first cell to access the first cell.

[0122] In some implementations, the random access procedure is a four-step random access procedure. In other implementations, the random access procedure is a two-step random access procedure. In some implementations, the random access procedure is a contention-free random access procedure. In other implementations, the random access procedure is a contention-based random access procedure. In the case of a four-step random access procedure, UE 102 sends message 3, including the UE identifier, to DU 174 via the first cell during the random access procedure. DU 174 responds to message 3 by sending a contention resolution message (e.g., message 4) to UE 102. In the case of a two-step random access procedure, UE 102 sends message A, including the UE identifier, to DU 174 via the first cell during the random access procedure. DU 174 responds to message A by sending a contention resolution message (e.g., message B) to UE 102. In some implementations, when UE 102 receives a contention resolution message from DU 174 on the first cell, UE 102 determines that UE 102 has successfully completed the random access procedure (i.e., UE 102 has successfully accessed the first cell). In some implementations, LTM DU configuration 1 includes a second C-RNTI, and the UE identifier is the second C-RNTI of UE 102. In this type of implementation, the contention resolution message is a PDCCH transmission addressed to the second C-RNTI. In other implementations, LTM DU configuration 1 does not include a C-RNTI, and the UE identifier is the first C-RNTI. In this type of implementation, the contention resolution message is a PDCCH transmission addressed to the first C-RNTI. In some implementations, DU 174 includes the second C-RNTI in a reconfiguration configuration with synchronization. In other implementations, DU 174 includes the second C-RNTI in LTM cell handover information.

[0123] When LTM DU configuration 1 includes a dedicated random access preamble, the random access procedure is a contention-free random access procedure. In this case, UE 102 sends the dedicated random access preamble to DU 174 via the first cell. When UE 102 receives a random access response including the ID of the dedicated random access preamble from DU 174 on the first cell, UE 102 determines that UE 102 has successfully completed the random access procedure (i.e., UE 102 has successfully accessed the first cell).

[0124] If DU 174 configures UE 102 to perform a random access procedure on the first cell as described above, then DU 174 will detect that UE 102 has accessed the first cell when it receives message 3, message A, or a special preamble during the random access procedure. If DU 174 configures UE 102 to skip the random access procedure, then DU 174 will detect that UE 102 has accessed the first cell when it receives the first transmission.

[0125] In some implementations, UE 102 transmits a first transmission (e.g., a PUSCH transmission) on the first cell using a UL grant. In some implementations, the first LTM command includes a UL grant. In other implementations, when UE 102 performs an LTM serving cell change to the first cell, in response to the first LTM command, UE 102 receives a first DCI including a UL grant on the PDCCH of the first cell. In some implementations, when UE 102 switches to the first cell in response to the first LTM command, UE 102 attempts to receive the first DCI or a UL grant by monitoring one or more PDCCHs on the first cell according to LTM DU configuration 1. While monitoring one or more PDCCHs on the first cell, UE 102 receives the first DCI and its CRC on the PDCCH. If LTM DU configuration 1 includes a second C-RNTI, UE 102 uses the CRC and the second C-RNTI to determine that the first DCI was transmitted to UE 102. In the case where LTM DU configuration 1 does not include a second C-RNT, UE 102 uses CRC and the first C-RNTI to determine that the first DCI is sent to UE 102.

[0126] In some implementations, CU 172 transmits at least one first TCI state configuration (e.g., LTM TCI state configuration) for the first cell to UE 102 via DU 174. In some implementations, each of the first TCI state configurations configures a TCI state for UE 102 to transmit and / or receive data and / or control signals on the first cell. Each TCI state associates or includes one or two DL RSs with a corresponding QCL type, and the DL RSs may be associated with a specific cell in cells 1, ..., N. DL RSs include SSBs and / or Tracking Reference Signals (TRS). In some implementations, CU 172 receives a DU-to-CU message including the first TCI state configuration from DU 174 and transmits an RRC message including the first TCI state configuration to UE 102 via DU 174. In other implementations, DU 174 includes the first TCI state configuration in the serving DU configuration (e.g., ...). CellGroupConfigIn the IE (Internet Context Modification) message, the service DU configuration is included in the DU to CU message. In some implementations, the DU to CU message is DU to CU message 310 or DU to CU message 314. In other implementations, the DU to CU message is a different message from messages 310 and 314. For example, the DU to CU message is a UE context modification response message or a UE context modification request message.

[0127] In some implementations, DU 174 includes LTM DU configuration 1 in the first interface protocol IE / field of the DU to CU message 310, and includes the service DU configuration in the second interface protocol IE / field of the DU to CU message 314. In some implementations, events 312 (optional) and / or 314 (optional) Figure 3 This is collectively referred to as the LTM TCI state configuration process 392.

[0128] In some implementations, CU 172 includes the service DU configuration in the RRC message. In some implementations, CU 172 avoids including the service DU configuration in the container used for LTM (e.g., the first container). In some implementations, CU 172 includes LTM ID 1 and the first LTM TCI state configuration in an element used for LTM, an add or modify list used for LTM, or a container, and CU 172 includes this element, the add or modify list used for LTM, or the container in the RRC message, respectively similar to element 1, the first add or modify list, or the first container. In some implementations, the RRC message is RRC reconfiguration messages 316, 318. In such cases, CU 172 may include the first LTM TCI state configuration in element 1. In other implementations, the RRC reconfiguration is another RRC reconfiguration message (…). Figure 3 (Not shown in the image). In some implementations, DU 174 also includes the first TCI state configuration in LTM DU configuration 1. In other implementations, DU 174 avoids including the first TCI state configuration in LTM DU configuration 1.

[0129] In some implementations, the first interface protocol IE / field is the first F1AP IE / field, and the second interface protocol IE / field is the second F1AP IE / field. In some implementations, one of the first F1AP IE / field and the second F1AP IE / field is the F1AP CellGroupConfig IE / field, and the other is not the F1AP CellGroupConfig IE / field. In some implementations, DU 174 includes the first F1AP IE / field in message 314. DU to CU RRC informationIn IE, and include the second F1AP IE / field in the DU to CU message. DU to CU RRC information In IE. In other implementations, neither the first F1AP IE / field nor the second F1AP IE is the F1AP CellGroupConfig IE / field. In other implementations, the second F1AP IE / field is. DU to CU RRC information IE, and the first F1AP IE / field is a new IE specifically for including LTM DU configuration.

[0130] In some implementations, DU 174 sends at least one first LTM TCI state activation / deactivation command (325) to UE 102 to activate some first LTM TCI state configurations. UE 102, in response to the first LTM TCI state activation / deactivation command, activates these first LTM TCI state configurations. In some implementations, DU 174 indicates deactivation of some of the first LTM TCI state configurations in some of the first LTM TCI state activation / deactivation commands. In some implementations, DU 174 transmits one or more DL RSs on the candidate cell using the activated LTM TCI state configuration or the first LTM TCI state configuration. The DL RS may include one or more SSBs and / or one or more TRSs. In some implementations, UE 102 receives the DL RS using the activated LTM TCI state configuration. UE 102 can obtain L1 measurement results from the received DL RS and transmit the L1 measurement results to DU 174. UE 102 can obtain L3 measurement results from the received DL RS and transmit the L3 measurement results to CU 172 via DU 174. In some implementations, DU 174 avoids using the first LTM TCI state configuration to communicate with UE 102 on the serving cell. In some implementations, UE 102 avoids using the first LTM TCI state configuration to communicate with DU 174 on the serving cell.

[0131] In some implementations, each first LTM TCI state activation / deactivation command is a MAC CE (e.g., candidate cell TCI state activation / deactivation command). In some implementations, DU 174 includes LTM ID 1 in each first LTM TCI state activation / deactivation command to identify the first LTM TCI state configuration. In other implementations, DU 174 includes a candidate cell index (e.g., cell index 1) in each first LTM TCI state activation / deactivation command to identify the first LTM TCI state configuration. In such cases, the candidate cell index is different from LTM ID 1. In some implementations, each first LTM TCI state configuration may include a candidate cell index. Alternatively, CU 172 includes the candidate cell index in an RRC message that includes the first LTM TCI state configuration. For example, CU 172 includes the candidate cell index in element 1. In some alternative implementations, UE 102 and DU 174 determine the candidate cell index from the PCI of the first cell. In such cases, the first BS 104 does not send the candidate cell index to the UE 102.

[0132] In some implementations, after receiving the first LTM command or accessing the first cell (e.g., in response to this), UE 102 performs DL reception (e.g., monitoring one or more PDCCHs) or UL transmission on the first cell using some or all of the first LTM TCI state configurations in event 336. In other implementations, after receiving the first LTM command or accessing the first cell (e.g., in response to this), UE 102 does not perform DL reception (e.g., monitoring one or more PDCCHs) or UL transmission on the first cell using the first LTM TCI state configurations in event 336.

[0133] In some implementations, each first LTM TCI state configuration includes a TCI state ID identifying the corresponding TCI state configuration. For example, the first LTM TCI state configuration includes LTM TCI state configurations 1, ..., L, where L is a positive integer greater than zero. LTM TCI state configurations 1, ..., L each include a TCI state ID 1, ..., L identifying the LTM TCI state configuration 1, ..., L. In some implementations, DU 174 includes TCI state ID 1 in the first LTM command to instruct UE 102 to activate LTM TCI state configuration 1 for communication on the first cell. UE 102 activates LTM TCI state configuration 1 in response to receiving TCI state ID 1 in the first LTM command. In some implementations, UE 102 uses (activated) LTM TCI state configuration 1 for access 332 on the first cell. In other implementations, UE 102 does not use the first LTM TCI state configuration for access 332 on the first cell. In some implementations, UE 102 uses (activated) LTM TCI state configuration 1 to communicate on the first cell 336. In some implementations, DU 174 uses activated LTM TCI state configuration 1 to communicate with UE 102 on the first cell 336.

[0134] In some implementations, in events 332 and / or 336, UE 102 uses LTM TCI state configuration 1 to monitor one or more PDCCHs, receive one or more DL RSs, receive one or more PDSCH transmissions, and / or transmit a first transmission and / or one or more additional transmissions. In some implementations, DU 174 detects 332 to UE 102 accessing a first cell based on LTM TCI state configuration 1, and / or communicates with UE 102 on the first cell 336. In some implementations, DU 174 receives the first transmission 332 and / or the additional transmission 336 from UE 102 on the first cell based on TCI state configuration 1. In other implementations, in events 332 and / or 336, DU 174 transmits one or more PDCCHs, one or more PDSCH transmissions, and / or one or more DL RSs based on LTM TCI state configuration 1.

[0135] In some implementations, DU 174 includes TCI State ID 2 in addition to TCI State ID 1 in the first LTM command to instruct UE 102 to activate TCI State Configuration 2 for communication on the first cell. UE 102 activates LTM TCI State Configuration 1 in response to receiving TCI State ID 1 in the first LTM command, and activates LTM TCI State Configuration 2 in response to receiving TCI State ID 2 in the first LTM command. After receiving the first LTM command (e.g., in response to this), UE 102 uses the activated LTM TCI State Configurations 1 and 2 for access 332 and / or communication 336 on the first cell. After sending the first LTM command or receiving an acknowledgment 331 (e.g., in response to this), DU 174 communicates with UE 102 on the first cell using the activated LTM TCI State Configurations 1 and 2 in events 332 and / or 336.

[0136] In some implementations, after one or more TCI state configurations (e.g., TCI state configuration 1 and / or 2) indicated in the application LTM command (e.g., the first LTM command) are specified, UE 102 spends time (e.g., beam application time or cell handover delay) to acquire the TCI state configured in that TCI state configuration (e.g., synchronizing and / or receiving the DL RS configured in that TCI state configuration). The time for acquiring the TCI state is considered the handover delay. In such cases, DU 174 takes this handover delay into account when communicating with UE 102 on the first cell in events 332 and / or 336. For example, after sending the first LTM command or receiving acknowledgment 331, DU 174, after this handover delay, begins communicating with UE 102 on the first cell using the active LTM TCI state configuration 1 and / or 2 in events 332 and / or 336.

[0137] In some implementations, UE 102 uses LTM TCI state configuration 1 to monitor one or more PDCCHs, receive one or more DL RSs, and / or receive one or more PDSCH transmissions from DU 174 on the first cell, and uses LTM TCI state configuration 2 to send a first transmission and / or one or more additional transmissions to DU 174 on the first cell. In such implementations, DU 174 uses LTM TCI state configuration 1 to send one or more control signals, one or more PDCCHs, one or more DL RSs, and / or one or more PDSCH transmissions to UE 102 on the first cell, and uses LTM TCI state configuration 2 to receive a first transmission and / or one or more additional transmissions from UE 102 on the first cell. Each control signal includes a DCI and a scrambling CRC for that DCI.

[0138] In other implementations, UE 102 uses LTM TCI state configuration 1 to monitor one or more PDCCHs from DU 174 on the first cell, and uses LTM TCI state configuration 2 to receive one or more PDSCH transmissions from DU 174 on the first cell. Each control signal includes a DCI and a scrambling CRC for that DCI. In this type of implementation, DU 174 uses LTM TCI state configuration 1 to send one or more control signals to UE 102 on one or more PDCCHs on the first cell, and uses LTM TCI state configuration 2 to send one or more PDSCH transmissions to UE 102 on the first cell. In some implementations, UE 102 uses LTM TCI state configuration 1 to send a first transmission and / or one or more additional transmissions to DU 174 on the first cell. In this type of implementation, DU 174 uses LTM TCI state configuration 1 to receive a first transmission and / or one or more additional transmissions from UE 102 on the first cell. In other implementations, UE 102 may use LTM TCI state configuration 2 to send a first transmission and / or one or more additional transmissions to DU 174 on the first cell. In such implementations, DU 174 may use LTM TCI state configuration 2 to receive the first transmission and / or one or more additional transmissions from UE 102 on the first cell.

[0139] In another implementation, UE 102 uses TCI state configuration 1 and TCI state configuration 2 to monitor one or more PDCCHs on the first cell, and uses one of TCI state configuration 1 and TCI state configuration 2 to transmit a first transmission and / or one or more additional transmissions on the first cell. In this implementation, DU 174 uses LTM TCI state configuration 2 to transmit one or more control signals on one or more PDCCHs, and receives the first transmission and / or one or more additional transmissions from UE 102 on the first cell. Each control signal includes a DCI and a scrambling CRC for that DCI.

[0140] In some implementations, CU 172 receives, for example, a CN-to-BS message including the UE capability IE of UE 102 from a CN (e.g., CN 110 or AMF 164) during event 302. For example, the CN-to-BS message is an NG Application Protocol (NGAP) message. In other implementations, CU 172 receives, for example, a BS-to-BS message including the UE capability IE from another BS (e.g., a second BS 106) before event 302. In yet another implementation, CU 172 receives, for example, a UE capability information message including the UE capability IE from UE 102 via DU 174 or another DU during event 302. In some implementations, DU 174 receives the UE capability IE of UE 102 (e.g., UE-NR-Capability or UE-6G-Capability) from CU 172 during event 302.

[0141] In some alternative implementations, DU 174 may not activate or may determine that the (LTM) TCI state configuration is inactive in the first LTM command. In such cases, DU 174 does not include the TCI state ID in the first LTM command. Therefore, when UE 102 receives a first LTM command that does not include the TCI state configuration, UE 102 avoids using the first LTM TCI configuration for access and / or communication on the first cell. In some implementations, if the UE capability IE indicates that UE 102 does not support No Random Access Channel (RACH) LTM, then DU 174 does not include the TCI state ID in the first LTM command or avoids including the TCI state ID in the first LTM command. Otherwise, if the UE capability IE indicates that UE 102 supports No RACH LTM, then DU 174 includes the one or more TCI state IDs (e.g., TCI state ID 1 and / or TCI state ID 2) in the first LTM command. In other implementations, if DU 174 does not configure LTM TCI state configuration for the first cell for UE 102, then DU 174 does not include the TCI state ID in the first LTM command or avoids including the TCI state ID in the first LTM command. Otherwise, if DU 174 configures one or more LTM TCI state configurations (e.g., the first LTM TCI state configuration), then DU 174 includes one or more LTM TCI state IDs (e.g., TCI state ID 1 and / or TCI state ID 2) in the first LTM command.

[0142] In some implementations, UE 102 stops using or deactivates the first non-LTMTCI configuration when it receives the first LTM command.

[0143] After successfully accessing the first cell, UE 102 communicates with DU 174 on the first cell using LTM DU configuration 1 and / or reference LTM DU configuration 336, and communicates with CU 172 via DU 174. In this case, DU 174 uses LTM DU configuration 1 to communicate with UE 102 on the first cell 336. In some scenarios or implementations, UE 102 communicates with DU 174 on the first cell 336 via PUSCH transmission, PDSCH transmission, PUCCH transmission, PDCCH transmission, and / or sounding reference signal (SRS) transmission.

[0144] When UE 102 receives the reference LTM DU configuration as described above, UE 102 communicates with DU 174 on the first cell 336 according to at least a portion of LTM DU configuration 1 and the reference LTM DU configuration. In other words, UE 102 communicates with DU 174 336 according to the configuration parameters in LTM DU configuration 1 and the reference LTM DU configuration. Similarly, DU 174 communicates with UE 102 on the first cell 336 according to at least a portion of LTM DU configuration 1 and the reference LTM DU configuration. In other words, DU 174 communicates with UE 102 336 according to the configuration parameters in LTM DU configuration 1 and the reference LTM DU configuration.

[0145] If UE 102 receives neither LTM CU Configuration 1 nor Reference LTM CU Configuration, UE 102 communicates with CU 172 via DU 174 using the serving CU configuration 336. Correspondingly, if CU 172 neither sends LTM CU Configuration 1 nor Reference CU Configuration to UE 102, CU 172 communicates with UE 102 via DU 174 using the serving CU configuration 336. If UE 102 receives both LTM CU Configuration 1 and Reference LTM CU Configuration from CU 172, UE 102 communicates with CU 172 via DU 174 using LTMCU Configuration 1 and at least a portion of the reference LTM CU Configuration not enhanced by LTM CU Configuration 1 336. In this case, CU 172 communicates with UE 102 via DU 174 using LTM CU Configuration 1 and at least a portion of the reference LTMCU Configuration not enhanced by LTM CU Configuration 1 336.

[0146] If UE 102 receives LTM CU configuration 1 from CU 172 but does not receive a reference LTM CU configuration, UE 102 communicates with CU 172 via DU 174 using LTM CU configuration 1 336. In this case, CU 172 communicates with UE 102 via DU 174 using LTM CU configuration 1 336. If LTM CU configuration 1 is fully configured, UE 102 and CU 172 communicate with each other via DU 174 using LTM CU configuration 1 instead of the serving CU configuration 336. In some implementations, if UE 102 does not receive a reference LTM CU configuration from the first BS 104, UE 102 determines that LTM CU configuration 1 is fully configured. Accordingly, if CU 172 determines to configure LTM CU configuration 1 as fully configured, CU 172 does not send a reference LTM CU configuration to UE 102. In other implementations, CU 172 includes a first indication (e.g., a field or IE) in LTMCU configuration 1, the first container, element 1, or the RRC reconfiguration message 316 to indicate that LTM CU configuration 1 is fully configured. If LTMCU configuration 1 is an incremental configuration for enhancing the service CU configuration, UE 102 and CU 172 communicate with each other via DU 174 336 using LTM CU configuration 1 and at least a portion of the service CU configuration not enhanced by LTM CU configuration 1. In some implementations, if UE 102 does not receive a reference LTM CU configuration from the first BS 104, UE 102 determines that LTM CU configuration 1 is an incremental configuration for enhancing the service CU configuration. Accordingly, if CU 172 determines that it wants to configure LTM CU configuration 1 as an incremental configuration for enhancing the service CU configuration, CU 172 does not send the reference LTM CU configuration to UE 102. In some implementations, CU 172 indicates that LTM CU Configuration 1 is an incremental configuration for enhancing service CU configuration by excluding the first indication in LTM CU Configuration 1, the first container, element 1, and / or RRC reconfiguration message 316. Alternatively, CU 172 includes a second indication (e.g., a field or IE) in LTM CU Configuration 1, the first container, element 1, or RRC reconfiguration message 316 to indicate that LTM CU Configuration 1 is an incremental configuration for enhancing service CU configuration. In some implementations, CU 172 indicates that LTM CU Configuration 1 is a full configuration by excluding the second indication in LTM CU Configuration 1, the first container, element 1, and / or RRC reconfiguration message 316.

[0147] If UE 102 receives a reference LTM CU configuration from CU 172 but does not receive LTM CU configuration 1, UE 102 communicates with CU 172 via DU 174 using the reference LTM CU configuration 336. In this case, CU 172 communicates with UE 102 via DU 174 using the reference LTM CU configuration 336. If the reference LTM CU configuration is fully configured, UE 102 and CU 172 communicate with each other via DU 174 using the reference LTM CU configuration instead of the serving CU configuration 336. In some implementations, UE 102 and CU 172 determine that reference LTM CU configuration 1 is a fully configured configuration as specified in the 3GPP specification (e.g., 3GPP TS 38.331). In other implementations, CU 172 includes a first indication (e.g., a field or IE) in the reference LTM CU configuration, the first container, or the RRC reconfiguration message 316 to indicate that the reference LTM CU configuration is fully configured. If the reference LTM CU configuration is an incremental configuration for enhancing the service CU configuration, then UE 102 and CU 172 communicate with each other via DU 174 336 using the reference LTM CU configuration and at least a portion of the service CU configuration not enhanced by the reference LTM CU configuration. In some implementations, CU 172 indicates that the reference LTM CU configuration is an incremental configuration for enhancing the service CU configuration by excluding a first indication in the reference LTM CU configuration, the first container, element 1, and / or the RRC reconfiguration message 316. Alternatively, CU 172 includes a second indication (e.g., a field or IE) in the reference LTM CU configuration, the first container, element 1, or the RRC reconfiguration message 316 to indicate that the reference LTM CU configuration is an incremental configuration for enhancing the service CU configuration. In some implementations, CU 172 indicates that the reference LTM CU configuration is a full configuration by excluding a second indication in the reference LTM CU configuration, the first container, element 1, and / or the RRC reconfiguration message 316.

[0148] If UE 102 neither receives the reference LTM CU configuration from CU 172 nor LTM CU configuration 1, UE 102 communicates with CU 172 via DU 174 using the serving LTM CU configuration 336. In this case, CU 172 communicates with UE 102 via DU 174 using the serving LTM CU configuration 336.

[0149] In some implementations, DU 174 includes or configures at least one second non-LTM TCI state configuration for the first cell in LTM DU configuration 1. When communicating with UE 102 at event 332 or 336, DU 174 may send a second non-LTM TCI state activation / deactivation command to UE 102 on the first cell to activate the second non-LTM TCI state configuration and / or deactivate the activated LTM TCI state configuration. In some implementations, DU 174 includes a serving cell index for the first cell in the second non-LTM TCI state activation / deactivation command. DU 174 includes this serving cell index in LTM DU configuration 1. In some implementations, UE 102 stops using or deactivates the (activated) LTM TCI state configuration in response to receiving the second non-LTM TCI state activation / deactivation command. In some implementations, the second non-LTM TCI state activation / deactivation command is a MAC CE. The MAC CE can be a TCI state activation / deactivation MAC CE for a UE-specific PDSCH, a TCI state indication MAC CE for a UE-specific PDCCH, a PUCCH spatial relationship activation / deactivation MAC CE, an enhanced TCI state activation / deactivation MAC CE for a UE-specific PDSCH, an enhanced PUCCH spatial relationship activation / deactivation MAC CE, an enhanced TCI state indication MAC CE for a UE-specific PDCCH, a PUCCH spatial relationship activation / deactivation MAC CE for multiple TRP PUCCH repetition, or a unified TCI state activation / deactivation MAC CE.

[0150] In some implementations, the second non-LTM state configuration can be a Rel-15 / 16 TCI state configuration (i.e., not a unified joint / DL / UL TCI state). This means that BS 104 can configure a Rel-15 / 16 beam indication frame for the first cell. The non-LTM TCI state configuration activated / indicated by the second non-LTM TCI state activation / deactivation command can be applicable only to a channel or RS (PDSCH / PDCCH / CSI-RS / PUCCH / SRS). In such implementations, if UE 102 receives a second non-LTM TCI state activation / deactivation command, the UE will stop or use the first LTM TCI state for channels or RSs that share / follow / apply the unified TCI state. For example, if UE 102 receives an Enhanced TCI State Indication MAC CE for a UE-specific PDCCH, UE 102 will deactivate or use the first LTM TCI state for at least one of other channels or RSs that also share / follow / apply a unified TCI state (e.g., PDSCH, PUSCH, PUCCH, CSI-RS, or SRS). If UE 102 receives a second non-LTM TCI state activation / deactivation command, UE 102 can deactivate the activated first LTM TCI state configuration.

[0151] In some implementations, the second non-LTM TCI state configuration includes at least one TCI state configured in the first LTM TCI state configuration. In other implementations, the TCI states in the second non-LTM TCI state configuration are different from the TCI states in the first LTM TCI state configuration. In some implementations, the second non-LTM TCI state configuration configures more TCI states than the first LTM TCI state configuration. In some other implementations, the TCI states in the second non-LTM TCI state configuration are the same as the TCI states in the first LTM TCI state configuration. BS 104 / CU 172 / DU 174 may notify UE 102 in an RRC message or signal whether the first LTM TCI state configuration is the same as, different from, or a subset of the second non-LTM TCI state configuration.

[0152] In some implementations, the first LTM TCI state configuration for the first cell is a subset of the second non-LTM TCI state configuration for the first cell. In some implementations, the TCI state ID of the first LTM TCI state configuration for the first cell does not overlap with or match the TCI state ID of the second non-LTM TCI state configuration for the first cell. This can mean that when UE 102 receives a second non-LTM TCI state activation / deactivation command, UE 102 considers / determines that the TCI state ID indicated in the second non-LTM TCI state activation / deactivation command refers to either the first LTM TCI state configuration or the second non-LTM TCI state configuration for the first cell. For example, the TCI state ID range for the first LTM TCI state configuration for the first cell is from #000 to #007; the TCI state ID range for the second non-LTM TCI state configuration for the first cell is from #008 to #015. In such examples, if the second non-LTM TCI state activation / deactivation command indicates TCI state ID #001, then UE 102 activates the first LTM TCI state configuration identified by TCI state ID #001; if the second non-LTM TCI state activation / deactivation command indicates TCI state ID #012, then UE 102 activates the second non-LTM TCI state configuration identified by TCI state ID #012. In some implementations, UE 102 combines or cascades the first LTM TCI state configuration for the first cell and the second non-LTM TCI state configuration for the first cell for non-LTM TCI state activation / indication purposes. In some implementations, UE 102 considers or determines the first LTM TCI state configuration for the first cell as the non-LTM TCI state configuration for the first cell.

[0153] In some implementations, DU 174 may not include or configure at least one second non-LTM TCI state configuration for the first cell in LTM DU configuration 1. In such cases, UE 102 considers or determines that at least one first TCI state configuration (e.g., LTM TCI state configuration) for the first cell is a non-LTM TCI state configuration for the first cell. This can mean that when UE 102 receives a second non-LTM TCI state activation / deactivation command, UE 102 considers / determines that the TCI state ID indicated in the second non-LTM TCI state activation / deactivation command refers to a first LTM TCI state configuration for the first cell. For example, if the second non-LTM TCI state activation / deactivation command indicates TCI state ID #000, then UE 102 activates and / or applies the first TCI state configuration (e.g., LTM TCI state configuration) identified by TCI state ID #000 and performs non-LTM communication in the first cell.

[0154] In some implementations, if a first LTM TCI state configuration is associated with or includes an SSB corresponding to QCL type A, UE 102 avoids using such a TCI state configuration for non-LTM purposes or communications in the first cell. In some implementations, UE 102 may consider or determine a first LTM TCI state configuration for the first cell as a non-LTM TCI state configuration for the first cell unless it includes or is associated with an SSB corresponding to QCL type A.

[0155] In some implementations, when DU 174 communicates with UE 102 on the first cell (332, 336) or simultaneously, DU 174 avoids sending an LTM TCI state activation / deactivation command to UE 102 to activate the LTM TCI state configuration for the first cell or associated with LTM ID1. In other implementations, when DU 174 communicates with UE 102 on the first cell (332, 336) or simultaneously, DU 174 sends a second LTM TCI state activation / deactivation command to UE 102 to activate at least one LTM TCI state configuration in the first LTM TCI state configuration that was not activated by the first LTM command. In response to the second LTM TCI state activation / deactivation command, UE 102 activates the LTM TCI state configuration indicated in the second LTM TCI state activation / deactivation command. In some implementations, in the second LTM TCI state activation / deactivation command, DU 174 may deactivate the LTM TCI state configuration activated in the first LTM command. In this situation, in response, UE 102 deactivates the LTM TCI state configuration activated in the first LTM command. UE 102 and DU 174 communicate with each other on the first cell using the LTM TCI state configuration activated by the second LTM TCI state activation / deactivation command, as described above.

[0156] In some implementations, UE 102 sends an RRC message (e.g., an RRC reconfiguration complete message) to CU 172 via DU 174 and the first cell to instruct UE 102 to apply LTM DU configuration 1. If UE 102 performs random access procedure 332, UE 102 may include this RRC message in message 3 or message A. Alternatively, UE 102 sends the RRC message after completing the random access procedure. If UE 102 skips random access procedure 332, UE 102 includes the RRC message in a PUSCH transmission of at least one PUSCH transmission. In some implementations, if UE 102 maintains communication on cell 124A of the first BS 104 (i.e., UE 102 does not disconnect from cell 124A), UE 102 may send the RRC message to the first BS 104 via cell 124A. When DU 174 receives the RRC message, DU 174 sends the RRC message to CU 172.

[0157] In other implementations, UE 102 avoids sending the RRC message to the first BS 104 in response to applying LTM DU configuration 1 or receiving a first LTM command. In such cases, UE 102 may include or send data in message 3, message A, or PUSCH transmission as described above. UE 102 may generate a MAC PDU and / or RLC PDU that includes the data, and send or include the MAC PDU and / or RLC PDU in the PUSCH transmission. For example, the data may be a PDCP PDU, SDAP PDU, LTE Positioning Protocol (LPP) PDU, RRC PDU, and / or NAS PDU. The RRC PDU includes a UL-DCCH- message that excludes the RRC reconfiguration completion message. The NAS PDU includes a Mobility Management (MM) message or a Session Management (SM) message. The MM message may be a 5G MM message or a 6G MM message, and the SM message may be a 5G SM message or a 6G SM message. When DU 174 receives the data, DU 174 sends the data to CU 172.

[0158] When DU 174 determines in event 332 or 336 that UE 102 has successfully connected to the first cell, DU 174 may send a 334 DU to CU message (e.g., access success message) to CU 172 (e.g., the CP of CU 172). In some implementations, DU 174 may include the cell ID 1 of the first cell in the DU to CU message of event 334. The cell ID may be PCI or CGI. Therefore, CU 172 determines that UE 102 is connected to the first cell after receiving the DU to CU message of event 334. When DU 174 determines in event 332 or 336 that UE 102 has successfully connected to the first cell, DU 174 may send a DL data transfer status message or frame to CU 172 (e.g., the UP of CU 172). In some implementations, upon receiving the DU to CU message 329, CU 172 may stop or suspend sending DL data for UE 102 to DU 174 until receiving the DU to CU message 334. CU 172 may do this because DU 174 is unable to buffer DL data for UE 102 during LTM execution in events 330 and / or 332. After receiving the DU to CU message 334, CU 172 resumes or continues sending DL data for UE 102 to DU 174. In other implementations, when CU 172 receives the DU to CU message 329, CU 172 may continue sending DL data for UE 102 to DU 174. CU 172 may do this because DU 174 can buffer DL data for UE 102 during LTM execution in events 330 and / or 332. When or after DU 174 detects that UE 102 has accessed cell 1, DU 174 sends DL data to UE 102 via cell 1.

[0159] In some implementations, when it is determined that UE 102 is connected to the first cell, sends the first LTM command 330, or receives an acknowledgment 331, DU 174 may stop communicating with UE 102 on cell 124A and / or release the resources of cell 124A configured for UE 102.

[0160] In some implementations, DU 174 may generate some or all of LTM DU configuration 1 and / or LTM DU configuration 2, ..., N as a complete configuration to replace the serving DU configuration. If LTM DU configuration 1 is a complete configuration, then UE 102 and DU 174 communicate with each other based on LTM DU configuration 1 instead of the serving DU configuration 336. In some implementations, DU 174 includes an indication that LTM DU configuration 1 is a complete configuration in LTM DU configuration 1. In each of LTM DU configurations 2, ..., N, DU 174 may include an indication that the corresponding DU configuration is a complete configuration. Each of the indications in LTM DU configurations 1, ..., N may be a field or IE (i.e., the same field or IE). In other implementations, CU 172 may include a single indication that LTM DU configuration 1 and / or 2, ..., N is a complete configuration in the RRC reconfiguration message of events 316, 318. In the case of the second container, CU 172 may include a single indication indicating that LTM DU configurations 2, ..., N are fully configured in the additional RRC reconfiguration message. In yet another implementation, CU 172 may include a single indication indicating that LTM DU configurations 1 and / or 2, ..., N are fully configured in the first container. In yet another implementation, for each of LTM DU configurations 2, ..., N, CU 172 may include a specific indication indicating that the corresponding LTM DU configuration is fully configured in the first container. In the case of the second container, CU 172 may include a single indication indicating that LTM DU configurations 2, ..., N are fully configured in the second container. In yet another implementation, CU 172 may include an indication indicating that LTM DU configuration 1 is fully configured in element 1. In each of elements 2, ..., N, CU 172 may include an indication indicating that the corresponding LTM DU configuration is fully configured. UE 102 can determine whether LTM DU configuration 1 and / or LTM DU configuration 2, ..., N are fully configured based on the above indications. In some implementations, each of the above indications corresponds to the one defined in the current 3GPP specification. fullConfig The fields differ. In some implementations, each of the above instructions is defined in the current 3GPP specification. fullConfig Field. If LTM DU configuration 1 is fully configured, and if received from the first BS 104, for example, in RRC reconfiguration message 318, then UE 102 in event 336 does not apply the reference LTM DU configuration. In such cases, DU 174 may not include the reference LTM DU configuration in the first DU to CU message 310.

[0161] In other implementations, DU 174 may generate LTM DU configuration 1 and / or LTM DU configuration 2, ..., N as incremental configurations that enhance a portion of the reference LTM DU configuration. In other words, DU 174 generates LTM DU configuration 1, ..., N based on the reference LTM DU configuration. For example, if LTM DU configuration 1 is an incremental configuration, then UE 102 and DU 174 enhance that portion of the reference LTM DU configuration with LTM DU configuration 1. Therefore, UE 102 and DU 174 communicate with each other 336 according to LTM DU configuration 1 and do not enhance a portion of the reference LTM DU configuration. In some implementations, LTM DU configuration 1 and / or 2, ..., N, the first container, the second container, or element 1, ..., N excludes indications that LTM DU configuration 1 and / or 2, ..., N is a full configuration to indicate that LTM DU configuration 1 and / or 2, ..., N is an incremental configuration. UE 102 can determine that each of LTM DU configurations 1 and / or 2, ..., N is an incremental configuration based on excluding the indication in LTM DU configuration 1 and / or 2, ..., N, first container, second container, or element 1 and / or 2, ..., N.

[0162] In some implementations, if UE 102 does not receive a reference LTM DU configuration for LTM DU configuration 1 and / or LTM DU configuration 2, ..., N, then UE 102 determines that LTM DU configuration 1 and / or LTM DU configuration 2, ..., N are complete configurations. Correspondingly, if DU 174 does not obtain a reference LTM DU configuration for UE 102 (i.e., DU 174 does not generate a reference LTM DU configuration for UE 102 and / or does not receive a reference LTM DU configuration for UE 102 from CU 172), then DU 174 generates LTM DU configuration 1 and / or LTM DU configuration 2, ..., N as complete configurations.

[0163] In other implementations, if UE 102 does not receive a reference LTM DU configuration for LTM DU configuration 1 and / or LTM DU configuration 2, ..., N, then UE 102 determines that LTM DU configuration 1 and / or LTM DU configuration 2, ..., N are incremental configurations for enhancing the service DU configuration. In such cases, UE 102 communicates with DU 174 336 based on at least a portion of the service DU configuration that is not enhanced by LTM DU configuration 1. Accordingly, if DU 174 does not obtain a reference LTM DU configuration for UE 102 (i.e., DU 174 does not generate a reference LTM DU configuration for UE 102 and / or receives a reference LTM DU configuration for UE 102 from CU 172), then DU 174 generates LTM DU configuration 1 and / or LTM DU configuration 2, ..., N as incremental configurations for enhancing the service DU configuration. In such cases, DU 174 communicates with UE 102 336 according to at least a portion of LTM DU configuration 1 and service DU configuration.

[0164] In some implementations, UE 102 uses a UE MAC entity (e.g., MAC 204B) to communicate with the DUMAC entity (e.g., MAC 204B) of DU 174 (e.g., events 302, 304, 318, 320, 324, 330, and / or 331). In some implementations, UE 102 resets the UE MAC entity after receiving a first LTM command or in response to it, and before performing the 332 random access procedure or communicating 336 with DU 174 via the first cell. In some implementations, DU 174 resets the DU MAC entity after sending the first LTM command, receiving an acknowledgment 331, or determining that UE 102 is connected to the first cell (e.g., in response to it).

[0165] In some implementations, when UE 102 resets the UE MAC entity, UE 102 performs at least one of the following actions on the UE MAC entity (i.e., UE MAC reset or full UE MAC reset): Configured logical channels Bj Initialize to zero; Stop one or more timers; If UE 102 is configured to perform a random access procedure (e.g., event 332) in a configuration (e.g., configuration 1), then timeAlignmentTimer It is considered due; Set the New Data Indicator (NDI) used in the UL HARQ process to a value of 0; Set the NDI used for HARQ process ID to a value of 0 to monitor PDCCH in sidelink resource allocation mode 1; Refresh the Msg3 buffer; Refresh the MSGA buffer; Cancel (if any) the triggered scheduling request process; Cancel (if any) the triggered buffer status reporting process; Cancel (if any) the triggered power margin reporting process; Cancel (if any) any consistent LBT faults that were triggered; Cancel any triggered BFRs; Cancel (if any) the sidelink buffer status reporting procedure that was triggered; Cancel (if any) the preemptive buffer status reporting procedure that was triggered; Cancel (if any) the timed advance reporting process that was triggered; Cancel (if any) the triggered referral rate query process; Cancel (if any) the uplink authorization confirmation triggered by the configuration; Cancel (if any) the sidelink authorization confirmation triggered by the configuration; Cancel any expected protection symbol queries triggered; Cancel (if any) the triggered positioning measurement gap activation / deactivation request process; Flush the soft buffer used for the DL HARQ process; For each of the DL HARQ processes, the next received transmission for TB is regarded as the first transmission; Release (if any) temporary C-RNTI; Reset one or more counters (e.g., BFI_COUNTER and / or LBT_COUNTER).

[0166] In some implementations, when DU 174 resets the DU MAC entity, DU 174 performs at least one of the following actions on the DU MAC entity (i.e., DU MAC reset or full DU MAC reset): Stop one or more timers; If UE 102 is configured to perform a random access procedure (e.g., event 332) in a configuration (e.g., configuration 1), then DU 174 will be used for UE 102 to initiate and / or maintain the procedure. timeAlignmentTimer It is considered expired; Set the NDI used for the DL HARQ process to a value of 0; Refresh the soft buffer used for the UL HARQ process; For each of the UL HARQ processes, the next received transmission for the TB is regarded as the first transmission; Reset one or more counters (e.g., BFI_COUNTER and / or LBT_COUNTER). Depending on the implementation, UE 102 may determine whether to partially or completely reset the UE MAC entity. In some implementations, when UE 102 resets the UE MAC entity as described above, UE 102 completely resets the UE MAC entity (i.e., a full UE MAC reset). In a full UE MAC reset, UE 102 performs some or all of the actions described above. In other implementations, when UE 102 resets the UE MAC entity as described above, UE 102 partially resets the UE MAC entity (i.e., a partial UE MAC reset). In a partial UE MAC reset, UE 102 performs some or a subset or part of the actions in a full UE MAC reset.

[0167] In some implementations, a partial UE MAC reset includes at least one of the following actions: If UE 102 is configured to perform a random access procedure (e.g., event 332) in a configuration (e.g., configuration 1), then UE 102's timeAlignmentTimer It is considered due; Refresh the Msg3 buffer; Refresh the MSGA buffer; Release (if any) temporary C-RNTI; Reset one or more counters (e.g., BFI_COUNTER and / or LBT_COUNTER).

[0168] In some implementations, a partial UE MAC reset further includes at least one of the following actions: Cancel (if any) the triggered scheduling request process; Cancel (if any) the triggered buffer status reporting process; Cancel (if any) the triggered power margin reporting process; Cancel (if any) any consistent LBT faults that were triggered; Cancel any triggered BFRs; Cancel (if any) the sidelink buffer status reporting procedure that was triggered; Cancel (if any) the preemptive buffer status reporting procedure that was triggered; Cancel (if any) the timed advance reporting process that was triggered; Cancel (if any) the triggered referral rate query process; Cancel (if any) the uplink authorization confirmation triggered by the configuration; Cancel (if any) the sidelink authorization confirmation triggered by the configuration; Cancel any expected protection symbol queries triggered; Cancel (if any) the triggered positioning measurement gap activation / deactivation request process; In some implementations, a partial UE MAC reset further includes at least one of the following actions: Stop the first part of one or more timers and keep the rest of one or more timers; Set the New Data Indicator (NDI) used in the UL HARQ process to a value of 0; Set the NDI used for HARQ process ID to a value of 0 to monitor PDCCH in sidelink resource allocation mode 1; Flush the soft buffer used for the DL HARQ process; For each of the DL HARQ processes, the next received transmission for TB is regarded as the first transmission; Depending on the implementation, DU 174 may determine whether to partially or completely reset the DU MAC entity. In some implementations, when DU 174 resets the DU MAC entity as described above, DU 174 completely resets the DU MAC entity (i.e., a full DU MAC reset). In a full DU MAC reset, DU 174 performs some or all of the actions described above. In other implementations, when DU 174 resets the DU MAC entity as described above, DU 174 partially resets the DU MAC entity (i.e., a partial DU MAC reset). In a partial DU MAC reset, DU 174 performs some or a subset or part of the actions in a full DU MAC reset.

[0169] In some implementations, a partial DU MAC reset includes at least one of the following actions in a partial MAC reset: If UE 102 is configured to perform a random access procedure (e.g., event 332) in a configuration (e.g., configuration 1), then DU 174 will be used for UE 102 to initiate and / or maintain the procedure. timeAlignmentTimer It is considered expired; Reset one or more counters (e.g., BFI_COUNTER and / or LBT_COUNTER). In some implementations, a partial DU MAC reset includes at least one of the following actions for a MAC entity (i.e., a DU MAC reset): Stop the first part of one or more timers and keep the rest of one or more timers; Set the NDI used for the DL HARQ process to a value of 0; Refresh the soft buffer used for the UL HARQ process; For each of the UL HARQ processes, the next received transmission for the TB is regarded as the first transmission; Reset one or more counters (e.g., BFI_COUNTER and / or LBT_COUNTER). In other implementations, UE 102 avoids resetting the UE MAC entity in response to receiving the first LTM command. Similarly, DU 174 avoids resetting the DU MAC entity after sending the first LTM command, receiving acknowledgment 331, or determining that UE 102 is connected to the first cell (e.g., in response to this). In other words, UE 102 communicates with DU 174 on the first cell using the UE MAC entity (without resetting). Similarly, DU 174 communicates with UE 102 on the first cell using the DU MAC entity (without resetting) during or after random access procedure 332 or after determining that UE 102 is connected to the first cell.

[0170] In some implementations, UE 102 uses at least one UE RLC entity (e.g., RLC 206B) to communicate RLC PDUs (e.g., events 302, 304, 318, 320, 324, 330, and / or 331) with at least one DU RLC entity (e.g., RLC 206B) of DU 174. In some implementations, UE 102 reconstructs some or all of the at least one UE RLC entity after receiving a first LTM command or in response to it, and before performing the 332 random access procedure or communicating 336 with DU 174 via the first cell. In some implementations, DU 174 reconstructs some or all of the at least one DU RLC entity after sending the first LTM command, receiving acknowledgment 331, or determining that UE 102 is connected to the first cell (e.g., in response to it).

[0171] In some implementations, LTM DU configuration 1 may or may not include one or more RLC reconstruction indications that configure UE 102 to rebuild some or all of at least one UE RLC entity (e.g., reestablishRLC(Field). If LTM DU configuration 1 includes an RLC reconstruction indication that configures UE 102 to rebuild the first UE RLC entity in at least one of the UE RLC entities used by UE 102 to communicate with DU 174 using the RLC PDU, then UE 102 rebuilds the first UE RLC entity in response to the RLC reconstruction indication and the first LTM command. In some implementations, UE 102 may rebuild the first UE RLC entity before performing the 332 random access procedure or before communicating with DU 174 via the first cell 336. In other implementations, UE 102 may rebuild the first UE RLC entity during or after performing the 332 random access procedure. Otherwise, if LTM DU configuration 1 does not include an RLC reconstruction indication, UE 102 avoids rebuilding the first UE RLC entity in response to the first LTM command.

[0172] In some implementations, when UE 102 reconstructs the first UE RLC entity, UE 102 performs at least one of the following actions on the first UE RLC entity: Discard RLC SDU, RLC SDU segment, and RLC PDU (if any); Stop and reset the timer (if it is running); Reset the state variable to its initial value.

[0173] In some implementations, state variables and timers are defined in 3GPP TS 38.322.

[0174] Otherwise, if LTM DU configuration 1 does not include an RLC reconstruction indication for the first UE RLC entity, then UE 102 avoids reconstructing the first UE RLC entity upon or when receiving the first LTM command. In other words, UE 102 avoids performing the action for reconstructing the first UE RLC entity of UE 102 upon or when receiving the first LTM command. In some implementations, if LTM DU configuration 1 or element 1 does not include an RLC reconstruction indication but includes an indication that configuration 1 is fully configured, then UE 102 may reconstruct the first UE RLC entity of UE 102 upon or when receiving the first LTM command. Otherwise, if LTM DU configuration 1 or element 1 does not include an RLC reconstruction indication and an indication that configuration 1 is fully configured, then UE 102 avoids reconstructing the first UE RLC entity upon or when receiving the first LTM command.

[0175] Similarly, DU 174 reconstructs some or all of at least one DU RLC entity (e.g., NR RLC 206B) used by DU 174 to communicate with at least one UERLC entity of UE 102 (e.g., events 302, 304, 318, 320, 324, 330 and / or 331) in response to an RLC reconstruction instruction. In some implementations, DU 174 reconstructs the first DU RLC entity among at least one DURLC entity after sending a first LTM command, receiving an acknowledgment from UE 102 for the first LTM command, or determining that UE 102 is connected to the first cell. In some implementations, the acknowledgment is a HARQ ACK. In other implementations, the acknowledgment is a MAC CE. In still other implementations, the acknowledgment is a PUCCH transmission. In some implementations, when the first BS 104 reconstructs the first DU RLC entity, DU 174 performs at least one of the following actions for the first DU RLC entity: Discard RLC SDU, RLC SDU segment, and RLC PDU (if any); Stop and reset the timer (if it is running); Reset the state variable to its initial value.

[0176] In some implementations, state variables and timers are defined in 3GPP TS 38.322.

[0177] In other implementations, UE 102 avoids rebuilding some or all of at least one UE RLC entity in response to receiving a first LTM command. Similarly, DU 174 avoids rebuilding some or more of at least one DU RLC entity after sending the first LTM command, receiving acknowledgment 331, or determining that UE 102 is connected to the first cell (e.g., in response to this). In other words, UE 102 communicates with DU 174 on the first cell using some or all of at least one UE RLC entity (not rebuilt). For example, some or all of at least one UE RLC entity includes a first UE RLC entity and / or a second UE RLC entity. Similarly, DU 174 communicates with UE 102 on the first cell during or after random access procedure 332 or after determining that UE 102 is connected to the first cell using some or all of at least one DU RLC entity (not rebuilt). For example, some or all of at least one DU RLC entity includes a first DU RLC entity and / or a second DU RLC entity.

[0178] In some implementations, at event 302, UE 102 uses at least one UE PDCP entity (e.g., PDCP 210) to communicate UL PDCP PDUs and / or DL ​​PDCPPDUs with at least one CU PDCP entity (e.g., PDCP 210) of CU 172. In some implementations, after receiving or in response to a first LTM command, UE 102 performs a PDCP recovery procedure for some or all of the at least one UE PDCP entity. For example, after receiving or in response to receiving a first LTM command, UE 102 performs a PDCP recovery procedure for the first UE PDCP entity among the at least one UE PDCP entities. During the PDCP recovery procedure, UE 102 may or may not rebuild the first UE PDCP entity. After performing or in response to performing the PDCP recovery procedure, UE 102 may retransmit at least a portion of the UL PDCP PDUs to CU 172 via DU 174 and the first cell at event 336. Similarly, after sending the first LTM command or in response to sending the first LTM command, CU 172 performs some or all of the PDCP recovery procedures for at least one CU PDCP entity. For example, after sending the first LTM command or in response to sending the first LTM command, CU 172 performs the PDCP recovery procedure for the first CU PDCP entity among at least one CU PDCP entity. In some implementations, CU 172 performs the PDCP recovery procedure for the first CU PDCP entity in response to receiving DU to CU message 329 or 334. In other implementations, CU 172 performs the PDCP recovery procedure for the first CU PDCP entity in response to receiving a DL data transfer status message. During the PDCP recovery procedure, CU 172 may or may not rebuild the first CU PDCP entity. After performing the PDCP recovery procedure or in response to performing the PDCP recovery procedure, CU 172 may retransmit at least a portion of the DL PDCP PDU to UE 102 via DU 174 and the first cell in event 336.

[0179] In other implementations, UE 102 avoids rebuilding some or all of at least one UE PDCP entity in response to receiving a first LTM command. For example, some or all of the at least one UE PDCP entity includes a first UE PDCP entity and / or a second UE PDCP entity. Similarly, CU 172 avoids rebuilding some or more of at least one CU PDCP entity after receiving a DU to CU message 329 or 340 (e.g., in response to this) or after receiving a DL data transfer status message (e.g., in response to this). In other words, UE 102 communicates with CU 172 using some or all of at least one UE PDCP entity (not rebuilt) via DU 174 and the first cell. For example, some or all of the at least one UE PDCP entity includes a first UE PDCP entity and / or a second UE PDCP entity. Similarly, CU 172 communicates with UE 102 using some or all of at least one CU PDCP entity (not rebuilt) via DU 174 and the first cell. For example, some or all of at least one CU PDCP entity includes a first CU PDCP entity and / or a second CU PDCP entity.

[0180] In some implementations, after determining that UE 102 is connected to the first cell, CU 172 can send a 338 CU to DU message to DU 174 (e.g., UE Context Modification Request The message instructs DU 174 to stop communicating with UE 102 and / or release or suspend resources of cell 124A configured for UE 102. In response, DU 174 may stop communicating with UE 102 on cell 124A and / or release or suspend resources of cell 124A configured for UE 102, and send a 340 DU to CU message to CU-172 (e.g., UE context modification response Message). Events 338 (optional) and 340 (optional) in Figure 3 This is collectively referred to as the resource release or modification process 396.

[0181] After communicating with DU 174 on the first cell, or simultaneously with communicating with DU on the first cell, events 344, 346, 348, 350, 351, 352, 354, and / or 356, respectively, similar to events 324, 326, 328, 330, 331, 332, 334, and / or 336, may occur. UE 102 sends at least one measurement report (344) to DU 174. The at least one measurement report includes at least one measurement result for the second cell (i.e., cell 2). The at least one measurement result indicates that the second cell is suitable for communication with UE 102 and / or the first cell is not suitable for communication with UE 102. Upon receiving at least one measurement report (e.g., in response to this), DU 174 determines to activate LTM DU configuration 2 and generates a second LTM command to activate LTM DU configuration 2 (i.e., the second LTM command instructs UE 102 to apply LTM DU configuration 2). Then, DU 174 sends 350 second LTM commands to UE 102 on the first cell.

[0182] When it is determined that LTM DU configuration 2 is activated, or a second LTM command is sent, or in response to this, DU 174 may send a DU-to-CU message 349 to CU 172 indicating that LTM is being performed. In some implementations, DU 174 includes cell ID 2 or ID2 (i.e., LTM ID) in the DU-to-CU message 349 to indicate that DU 174 wants to activate LTM DU configuration 2. DU may send the DU-to-CU message 349 to CU 172 before or after sending the LTM command 350.

[0183] The descriptions for events 324, 326, 328, 330, 331, 332, 334, and / or 336 can be applied to events 344, 346, 348, 350, 351, 352, 354, and / or 356 with simple modifications. For example, replace “Cell 124A,” “First LTM Command,” “First Cell,” “ID 2,” “LTM DU Configuration 2,” and / or “LTM CU Configuration 2” with “First Cell,” “Second LTM Command,” “Second Cell,” “ID 2,” “LTM DU Configuration 2,” and / or “LTM CU Configuration 1,” respectively.

[0184] Events 344, 346, 348, 350, 351, 352, and 354 are in Figure 3 These are collectively referred to as LTM execution process 398. Events 304, 306, 390, 392, 394, 324, 326, 328, 329, 330, 331, 332, 334, 336, 396, 398, and 356 are in... Figure 3This is collectively referred to as the LTM DU configuration and / or activation process 380.

[0185] Next reference Figure 4 In scenario 400, the first BS 104 includes CU 172, source DU (S-DU) 174A, and target DU (T-DU) 174B. S-DU 174A operates cell 124A and optionally additional cells, while T-DU 174B operates the first cell (e.g., cell 124C). Scenario 400 is similar to scenario 300. Therefore, the description for scenario 300 can be broadly applied to scenario 400. The differences between scenarios 300 and 400 are described below.

[0186] Initially, UE 102 uses the serving DU configuration to communicate with S-DU 174A on cell 124A 402, and communicates with CU 172 via S-DU 174A. S-DU 174A is similar to Figure 3The UE 102 serves as the DU 174 in the communication 402. During communication 402, the UE 102 sends at least one measurement report (e.g., an L3 measurement report) via S-DU 174A to CU 172 in steps 404 and 406. Based on at least one measurement report, CU 172 determines to prepare cell 1, ..., N for LTM for UE 102 (operated by T-DU 174B), where N is a positive integer greater than 0 or 1. Cell 1, ..., N are identified by cell IDs 1, ..., N, respectively. In response to this determination, CU 172 and T-DU 174B perform step 490, LTM preparation procedure, to (request T-DU 174B) prepare cell 1, ..., N for LTM for UE 102. N can be a positive integer greater than zero or 1. In LTM preparation procedure 490, CU 172 sends a CU-DU message including cell IDs 1, ..., N to T-DU 174B to request T-DU 174B to prepare cells 1, ..., N for UE 102 for LTM, similar to event 308. In response, T-DU 174B sends a DU-DU message including LTM DU configurations 1, ..., N to CU 172, similar to event 310. LTM DU configurations 1, ..., N configure cells 1, ..., N for LTM, respectively. Specifically, LTM DU configurations 1, ..., N include configuration parameters for communication on cells 1, ..., N, respectively. In some implementations, the CU-DU message and DU-CU message in procedure 490 are the UE context establishment request message and UE context establishment response message, respectively. CU 172 then sends LTM DU configurations 1, ..., N in an RRC reconfiguration message in LTM configuration transfer procedure 494, similar to LTM configuration transfer procedure 394. In some implementations, the T-DU 174B can include cell indices 1, ..., N in LTM DU configurations 1, ..., N, respectively. In some implementations, the CU 172 can set cell indices 1, ..., N to different values ​​and include cell indices 1, ..., N in the CU-DU message of procedure 490.

[0187] After performing LTM preparation procedure 490, CU 172 may perform an additional LTM preparation procedure with T-DU 174B to prepare cells N+1, ..., N+M for LTM for UE 102, similar to procedure 490. M is a positive integer greater than zero. Similar to events 404 and 406, CU 172 may determine to do so based on one or more measurement reports received from UE 102 via S-DU 174A. During the additional LTM preparation procedure, CU 172 sends a CU-DU message to T-DU 174B including cell IDs N+1, ..., N+M to request T-DU 174B to prepare cells N+1, ..., N+M for LTM for UE 102. Cell IDs N+1, ..., N+M identify cells N+1, ..., N+M, respectively. In response to the CU-DU message, T-DU 174B sends a DU-DU message to CU 172 including LTM DU configurations N+1, ..., N+M. The LTM DU configurations N+1, ..., N+M are for LTM configuration cells N+1, ..., N+M, respectively. Specifically, the LTM DU configurations N+1, ..., N+M include configuration parameters for communication on cells N+1, ..., N+M. CU 172 then sends the LTM DU configurations N+1, ..., N+M in an RRC reconfiguration message during the additional LTM DU configuration transfer process, similar to LTM configuration transfer process 394 or 494.

[0188] In some implementations, LTM preparation procedure 490 is a UE context establishment procedure, and additional LTM preparation procedure is a UE context modification procedure.

[0189] In some implementations, CU 172 and S-DU 174A can execute procedure 380 with UE 102, such as for... Figure 3 As described above. In procedure 380, CU 172 and S-DU 174A perform procedures 390 and / or 392 to prepare the S-DU 174A cell for LTM for UE 102. Note that in procedure 380 or for Figure 3 The described value N can be related to... Figure 4The described value N may be the same or different. In procedure 390, CU 172 may receive a first DU-to-CU message including the reference LTM DU configuration from S-DU 174A in event 310. In other implementations, CU 172 and S-DU 174A do not perform procedure 380 with UE 102. In such cases, CU 172 may perform a 488 reference LTM DU configuration query procedure with S-DU 174A to obtain the reference LTM DU configuration. In procedure 488, CU 172 sends a 460 CU-to-DU message to S-DU 174A to request or query the reference LTM DU configuration. In some implementations, CU 172 may include an indication of requesting or querying the reference LTM DU configuration in the CU-to-DU message. In response to this indication or CU-to-DU message 460, S-DU 174A sends a 462 DU-to-CU message including the reference LTM DU configuration to CU 172. In some implementations, the indication is a reference LTM DU configuration query indication. In other implementations, the indication is an LTM indication, and CU 172 may include the query indication (e.g., GNB-DU configuration query IE) in the CU-DU message. After receiving the reference LTM DU configuration (i.e., in process 390 or process 488), CU 172 includes the reference LTM DU configuration (received from S-DU 174A) in the CU-DU message in LTM preparation process 490. T-DU 174B generates LTM DU configurations 1, ..., N based on the reference LTM DU configuration received from CU 172. In such cases, T-DU 174B does not include the reference LTM DU configuration in the DU-CU message in process 490. In the case of an additional LTM preparation process, T-DU 174B does not include the reference LTM DU configuration in the DU-CU message in the additional LTM preparation process. CU 172 may omit the reference LTM DU configuration from the CU-DU message during the additional LTM preparation process with T-DU 174B. In the case of the additional LTM preparation process, T-DU 174B generates LTM DU configurations N+1, ..., N+M based on the reference LTM DU configuration received from CU 172.

[0190] In some implementations, CU 172 does not provide a reference LTM DU configuration to T-DU 174B during LTM preparation procedure 490. In this case, T-DU 174B generates a reference LTM DU configuration and generates LTM DU configurations 1, ..., N based on the reference LTM DU configuration. In this case, T-DU 174B includes the reference LTM DU configuration in the DU-to-CU message in procedure 490. CU 172 sends the reference LTM DU configuration in the RRC reconfiguration message in procedure 490. In the case of an additional LTM preparation procedure, T-DU 174B generates LTM DU configurations N+1, ..., N+M based on the reference LTM DU configuration. In this case, T-DU 174B may not include the reference LTM DU configuration in the DU-to-CU message during the additional LTM preparation procedure. In some implementations, the reference LTM DU configuration generated by T-DU 174B differs from the reference LTM DU configuration generated by S-DU 174A. In other implementations, the reference LTM DU configuration generated by T-DU 174B is the same as the reference LTM DU configuration generated by S-DU 174A.

[0191] In some implementations, CU 172 includes the LTM DU configurations 1, ..., N of process 380 in the CU to DU message of process 490, and T-DU 174B generates LTM DU configurations 1, ..., N and / or N+1, ..., N+M taking into account or based on the configurations in the LTM DU configurations of process 380.

[0192] In some implementations, the LTM DU configuration X of process 380 includes at least one reference signal (RS) resource configuration X, where 1 ≤ X ≤ N. Each configuration in RS resource configuration X is associated with one or more RSs or one or more RS resources of cell X of S-DU 174A. RSs include SSB and / or CSI-RS. RS resources include SSB resources and / or CSI-RS resources. In some implementations, each of RS resource configurations X includes an RS resource configuration ID. In some implementations, RS resource configuration X is... CSI-ResourceConfig IE (and similar). In some implementations, the LTM DU configuration X includes... CSI- MeasConfig IE, and CSI-MeasConfig IE includes CSI-ResourceConfig IE. The T-DU 174B generates at least one reporting configuration 1 for reporting measurement results of RS or RS resources on cell 1 of the T-DU 174B, and includes the reporting configuration 1 in the LTM DU configuration 1. In some implementations, the reporting configuration 1 is CSI-ReportConfigIE (and similar). In some implementations, the T-DU 174B generates at least one RS resource configuration 1 taking into account or based on RS resource configuration X, and includes RS resource configuration 1 in LTM DU configuration 1. In some implementations, the T-DU 174B includes RS resource configuration X in RS resource configuration 1. In other implementations, the T-DU 174B includes each of RS resource configurations X in RS resource configuration 1, except for the RS resource configuration ID in RS resource configuration X. The T-DU 174B assigns the RS resource configuration ID as a value for each of RS resource configuration 1 (including RS resource configuration X), and includes the RS resource configuration ID in the corresponding RS resource configuration.

[0193] In some implementations, Report Configuration 1 configures one or more UL resources (e.g., PUCCH or PUSCH resources) for UE 102 on cell 1 to transmit measurement results. In some implementations, each of Report Configuration 1 includes one or more RS resource configuration IDs identifying one or more RS resource configurations included in RS Resource Configuration 1. After UE 102 performs an LTM serving cell change from cell 124A to cell 1, UE 102 communicates with S-DU 174B (i.e., T-DU 17B becomes UE 102's S-DU) and transmits measurement results on UL resources to S-DU 174B via cell 1 according to Report Configuration 1. Accordingly, S-DU 174B receives measurement results on UL resources from UE 102 via cell 1 according to Report Configuration 1. In some implementations, each of the measurement results includes one or more RS resource indicators and / or one or more quantized measurement values. UE 102 performs measurements on RS or RS resources according to RS Resource Configuration 1 and / or Report Configuration 1 and obtains quantized measurement values ​​from the measurements. In some implementations, the RS resource indicator instructs UE 102 to perform a measurement or obtain a quantized measurement value from an RS or RS resource. In some implementations, the RS resource indicator includes one or more SSB resource indicators (SSBRIs) and / or one or more CSI-RS resource indicators (CRIs). The quantized measurement value may include one or more L1-RSRP values ​​and / or one or more L1-SINR values.

[0194] In some implementations, the T-DU 174B also includes additional RS resource configurations in LTM DU configuration 1. Each configuration in the additional RS resource configurations is associated with one or more additional RSs or one or more additional RS resources in cell 1. Additional RSs include SSBs and / or CSI-RSs. Additional RS resources include SSB resources and / or CSI-RS resources. In some implementations, each of the additional RS resource configurations includes an RS resource configuration ID. In some implementations, the additional RS resource configuration is... CSI-ResourceConfig IE (and similar). In some implementations, the T-DU 174B will CSI- ResourceConfig IE includes CSI-MeasConfig In the IE (Internet Protocol Version 1), the T-DU 174B generates at least one additional reporting configuration for reporting measurement results of RS or RS resources on cell 1 of the T-DU 174B, and includes the additional reporting configuration in LTMDU configuration 1. In some implementations, the additional reporting configuration is... CSI-ReportConfig IE (and similar systems).

[0195] In some implementations, the additional report configuration allows UE 102 to configure one or more UL resources (e.g., PUCCH or PUSCH resources) on cell 1 to send measurement results. In some implementations, each of the additional report configurations includes one or more RS resource configuration IDs identifying one or more RS resource configurations included in the additional RS resource configuration. After UE 102 performs an LTM serving cell change from cell 124A to cell 1, UE 102 communicates with S-DU 174B 436 and sends measurement results to S-DU 174B via cell 1 on the UL resources according to the additional report configuration. Correspondingly, S-DU 174B receives the measurement results on the UL resources from UE 102 via cell 1 according to the additional report configuration. In some implementations, each of the measurement results includes one or more RS resource indicators and / or one or more quantized measurement values. UE 102 performs measurements on the additional RS or additional RS resources according to the additional RS resource configuration and / or additional report configuration and obtains quantized measurement values ​​from the measurements. In some implementations, the RS resource indicator instructs UE 102 to perform measurements or obtain additional RS or RS resources for quantizing measurement values. In some implementations, the RS resource indicator includes one or more SSB resource indicators (SSBRI) and / or one or more CSI-RS resource indicators (CRI). Quantized measurement values ​​may include one or more L1-RSRP values ​​and / or one or more L1-SINR values.

[0196] Similarly, T-DU 174B may consider or generate RS resource configurations 2, ..., N and / or N+1, ..., N+M and / or report configurations 2, ..., N and / or N+1, ..., N+M based on RS resource configuration X, and include RS resource configurations 2, ..., N and / or N+1, ..., N+M and / or report configurations 2, ..., N and / or N+1, ..., N+M in LTM DU configurations 2, ..., N and / or N+1, ..., N+M, as described above.

[0197] In other implementations, the LTM DU configuration X of procedure 380 includes at least one TCI state configuration X, where 1 ≤ X ≤ N. Each of the TCI state configurations X configures a TCI state that associates or includes one or two DL RSs with the corresponding QCL type. In some implementations, the DL RSs may be associated with a cell X operated by the S-DU174A. In some implementations, each of the TCI state configurations X includes a TCI state ID. In some implementations, each of the TCI state configurations X is... TCI-State IE. In some implementations, the TCI state configuration X includes / is ul-TCI-ToAddModList-r17 Fields, one or more TCI-UL-State-r17 IE dl- OrJointTCI-StateToAddModList-r17 Fields, one or more TCI-State IE TCI- ActivatedConfig IE and / or tci-StatesToAddModList Fields. In some implementations, the LTM DU configuration X includes... PDSCH-Config IE, and PDSCH-ConfigThe IE includes TCI state configuration X. In some implementations, the T-DU 174B generates at least one TCI state configuration 1 considering or based on TCI state configuration X, and includes TCI state configuration 1 in LTM DU configuration 1. In some implementations, TCI state configuration 1 includes TCI state configuration X. In other implementations, the T-DU 174B includes each of TCI state configurations X in TCI state configuration 1, except for the TCI state ID in TCI state configuration X. The T-DU 174B assigns the TCI state ID as a value for each of TCI state configurations 1 (including TCI state configuration X), and includes the TCI state ID in the corresponding TCI state configuration. When UE 102 and S-DU 174B communicate with each other 436, S-DU 174B may send an LTM command to UE 102 to instruct UE 102 to perform a fast serving cell change to cell X. The S-DU 174B includes a TCI state ID in the LTM command to instruct the UE 102 to apply a TCI state configuration identified by the TCI state ID to communicate on the cell X, wherein the TCI state configuration is one of TCI state configurations X, or a configuration that includes one of TCI state configurations X.

[0198] Similarly, T-DU 174B may generate TCI state configurations 2, ..., N based on RS resource configuration X, and include TCI state configurations 2, ..., N and / or N+1, ..., N+M in LTM DU configurations 2, ..., N and / or N+1, ..., N+M respectively, as described above.

[0199] In some implementations, when CU 172 executes process 380 after executing process 490, CU 172 includes the LTM DU configuration 1, ..., N of process 490 in the CU to DU message of process 380, and S-DU 174A considers or generates the LTM DU configuration 1, ..., N of process 380 based on the configuration in the LTM DU configuration of process 490, in a manner similar to that described above.

[0200] In some implementations, CU 172 assigns IDs 1, ..., N (received from T-DU 174B) for LTM DU configurations 1, ..., N, and performs procedure 492 with T-DU 174B to provide IDs 1, ..., N and / or cell IDs 1, ..., N, similar to procedure 392. Therefore, T-DU 174B associates IDs 1, ..., N with LTM DU configurations 1, ..., N and / or cell IDs 1, ..., N, respectively. In other implementations, T-DU 174B assigns IDs 1, ..., N (generated by T-DU 174B) for LTM DU configurations 1, ..., N, and includes IDs 1, ..., N in the DU-to-CU message of procedure 490, similar to event 310. In some implementations, CU 172 assigns IDs N+1, ..., N+M that identify LTM DU configurations N+1, ..., N+M respectively, and, similar to procedure 392, performs a procedure (similar to procedure 492) with T-DU 174B to provide IDs N+1, ..., N+M and / or cell IDs N+1, ..., N+M to T-DU 174B. Therefore, T-DU 174B associates IDs N+1, ..., N+M with LTM DU configurations N+1, ..., N+M and / or cell IDs N+1, ..., N+M respectively. In other implementations, T-DU 174B assigns IDs N+1, ..., N+M that identify LTM DU configurations N+1, ..., N+M respectively, and includes IDs 1, ..., N in the DU-to-CU message of the additional LTM preparation procedure, similar to event 310.

[0201] In some implementations, CU 172 sends a CU-DU message 412, including IDs 1, ..., N, to S-DU 174A, and receives a DU-CU message 414 from S-DU 174A in response. The CU-DU message 412 and the DU-CU message 414 are... Figure 4These are collectively referred to as LTM ID transmission procedure 493 or LTM cell index transmission procedure 493. In some implementations, messages 412 and 414 may be a UE context modification request message and a UE context modification response message, respectively. In some implementations, CU 172 includes LTM DU configuration 1, ..., N and / or cell ID 1, ..., N in CU to DU message 412. In one implementation, CU 172 includes ID 1, ..., N in CU to DU message 412. In another implementation, CU 172 includes cell index 1, ..., N in CU to DU message 412. In some alternative implementations, CU 172 may perform multiple LTM ID transmission procedures to send ID 1, ..., N, cell ID 1, ..., N and / or LTM DU configuration 1, ..., N to S-DU 174A. In each of these processes, CU 172 includes the following specific portions in a CU-DU message similar to message 412: ID 1, ..., N; Cell ID 1, ..., N; and / or LTM DU configuration 1, ..., N. Therefore, S-DU 174A associates ID 1, ..., N with LTM DU configuration 1, ..., N and / or Cell ID 1, ..., N, respectively. In other alternative implementations, CU 172 may perform multiple LTM cell index transmission procedures to send cell index 1, ..., N, cell ID 1, ..., N, and / or LTM DU configuration 1, ..., N to S-DU 174A. In each of these processes, CU 172 includes the following specific portions in a CU-DU message similar to message 412: Cell index 1, ..., N; Cell ID 1, ..., N; and / or LTM DU configuration 1, ..., N. Therefore, S-DU 174A associates cell indices 1, ..., N with LTM DU configurations 1, ..., N and / or cell IDs 1, ..., N, respectively.

[0202] In some implementations, S-DU 174A generates a first service DU configuration based on LTM DU configurations 1, 2, ..., and / or N, and includes the first service DU configuration in the DU-to-CU message 414. In some implementations, the first service DU configuration includes a configuration that updates (e.g., enhances, modifies, or replaces) service DU configuration 402. In other implementations, the first service DU configuration includes configurations not included in service DU configuration 402. CU 172 sends an RRC reconfiguration message including the first service DU configuration to UE 102. Upon receiving the RRC reconfiguration message, UE 102 applies the first service DU configuration to communicate with the service DU. For example, the RRC reconfiguration message is the RRC reconfiguration message in procedure 494 or similar. Depending on the implementation, UE 102 uses a configuration included in service DU configuration 402 that has not been updated by the first service DU configuration to communicate with S-DU 174A. The following are example implementations of generating the first service DU configuration based on LTM DU configurations 1, ..., N.

[0203] In some implementations, the LTM DU configuration Y of process 490 includes at least one RS resource configuration Y, where 1 ≤ Y ≤ N. Each configuration in RS resource configuration Y is associated with one or more RSs or one or more RS resources of cell Y of T-DU 174B. RSs include SSBs and / or CSI-RSs. RS resources include SSB resources and / or CSI-RS resources. In some implementations, each of RS resource configurations Y includes an RS resource configuration ID. In some implementations, RS resource configuration Y is... CSI- ResourceConfig IE (and similar). In some implementations, the LTM DU configuration includes... CSI-MeasConfig IE, and CSI-MeasConfig IE includes CSI-ResourceConfig IE. S-DU 174A generates at least one service reporting configuration for reporting measurement results of RS or RS resources on cell 124A, and includes the service reporting configuration in the first service DU configuration. In some implementations, the service reporting configuration is CSI-ReportConfigIE (and similar). In some implementations, S-DU 174A generates at least one service RS resource configuration considering or based on RS resource configuration Y, and includes the service RS resource configuration in the first service DU configuration. In some implementations, S-DU 174A includes RS resource configuration Y in the service RS resource configuration. In other implementations, S-DU 174A includes each of RS resource configurations Y in the service RS resource configuration, except for the RS resource configuration ID in RS resource configuration Y. S-DU 174A assigns the RS resource configuration ID as a value for each of the service RS resource configurations (including RS resource configuration Y), and includes the RS resource configuration ID in the corresponding service RS resource configuration.

[0204] In some implementations, the service report is configured for UE 102 to configure one or more UL resources (e.g., PUCCH or PUSCH resources) on cell 124A to send measurement results. In some implementations, each of the service report configurations includes one or more RS resource configuration IDs identifying one or more RS resource configurations included in the service RS resource configuration. When UE 102 communicates with S-DU 174A, UE 102 sends measurement results on the UL resources (e.g., event 424) to S-DU 174A via cell 124A according to the service report configuration. Correspondingly, S-DU 174A receives measurement results on the UL resources from UE 102 via cell 124A according to the service report configuration. In some implementations, each of the measurement results includes one or more RS resource indicators and / or one or more quantized measurement values. UE 102 performs measurements on the RS or RS resources according to the service RS resource configuration and / or service report configuration, and obtains quantized measurement values ​​from the measurements. In some implementations, the RS resource indicator instructs UE 102 to perform a measurement or obtain a quantized measurement value from an RS or RS resource. In some implementations, the RS resource indicator includes one or more SSB resource indicators (SSBRIs) and / or one or more CSI-RS resource indicators (CRIs). The quantized measurement value may include one or more L1-RSRP values ​​and / or one or more L1-SINR values.

[0205] In other implementations, the LTM DU configuration Y of procedure 490 includes at least one TCI state configuration Y, where 1 ≤ Y ≤ N. Each of the TCI state configurations Y configures a TCI state that associates or includes one or two DL RSs with the corresponding QCL type. In some implementations, the DL RSs may be associated with a cell Y operated by T-DU174B. In some implementations, each of the TCI state configurations Y includes a TCI state ID. In some implementations, each of the TCI state configurations Y is... TCI-State IE. In some implementations, the TCI state configuration Y includes / is ul-TCI-ToAddModList-r17 Fields, one or more TCI-UL-State-r17 IE dl- OrJointTCI-StateToAddModList-r17 Fields, one or more TCI-State IE TCI- ActivatedConfig IE and / or tci-StatesToAddModList Fields. In some implementations, the LTM DU configuration includes... PDSCH-Config IE, and PDSCH-Config The IE includes TCI state configuration Y. In some implementations, the S-DU 174A generates at least one serving TCI state configuration considering or based on TCI state configuration Y, and includes the serving TCI state configuration in the first serving DU configuration. In some implementations, serving TCI state configuration 1 includes TCI state configuration Y. In other implementations, the S-DU 174A includes each of the TCI state configurations Y in the serving TCI state configuration, except for the TCI state ID in TCI state configuration Y. The S-DU 174A assigns the TCI state ID as a value for each of the serving TCI state configurations (including TCI state configuration Y), and includes the TCI state ID in the corresponding serving TCI state configuration. When the S-DU 174A communicates with UE 102 436, the S-DU 174A may send an LTM command to UE 102 to instruct UE 102 to perform a fast serving cell change to cell Y. S-DU 174A includes the TCI state ID in the LTM command to instruct UE 102 to apply the TCI state configuration identified by the TCI state ID to communicate on the cell Y, wherein the TCI state configuration is one of the TCI state configurations Y, or a configuration that includes one of the TCI state configurations Y.

[0206] In some implementations, CU 172 sends a CU-DU message including IDs N+1, ..., N+M to S-DU 174A, and receives a DU-CU message from S-DU 174A in response. This CU-DU message and DU-CU message are similar to CU-DU message 412 and DU-CU message 414, respectively. In some implementations, CU 172 includes LTM DU configurations N+1, ..., N+M and / or cell IDs N+1, ..., N+M in the CU-DU message. In some alternative implementations, CU 172 may perform multiple LTM ID transmission procedures to send IDs N+1, ..., N+M, cell IDs N+1, ..., N+M, and / or LTM DU configurations N+1, ..., N+M to S-DU 174A. In each of these processes, CU 172 includes the following specific portions in a CU-DU message similar to message 412: IDs N+1, ..., N+M; cell IDs N+1, ..., N+M; and / or LTMDU configurations 1, ..., N. Therefore, S-DU 174A associates IDs N+1, ..., N+M with LTM DU configurations N+1, ..., N+M and / or cell IDs N+1, ..., N+M, respectively. In some implementations, S-DU 174A generates a second service DU configuration based on LTM DU configurations N+1, N+2, ..., and / or N+M, and includes the second service DU configuration in the DU-CU message. In some implementations, the second service DU configuration includes configurations that update (e.g., enhance, modify, or replace) the first service DU configuration and / or update configurations included in service DU configuration 402 but not updated by the first service DU configuration. In other implementations, the second service DU configuration includes configurations not included in the first service DU configuration. CU 172 sends an RRC reconfiguration message, including a second serving DU configuration, to UE 102 via S-DU 174A. Upon receiving the RRC reconfiguration message, UE 102 applies the second serving DU configuration to communicate with the serving DU. For example, the RRC reconfiguration message is the RRC reconfiguration message in procedure 494 or similar. Depending on the implementation, UE 102 communicates with S-DU 174A using a configuration included in serving DU configuration 402 and / or the first serving DU configuration and not updated by the second serving DU configuration. In some implementations, S-DU 174A generates one or more new L1 measurement configurations based on the L1 measurement configurations in LTM DU configurations N+1, N+2, ..., and / or N+M, and includes these new L1 measurement configurations in the second serving DU configuration.In some implementations, the S-DU 174A generates one or more new TCI state configurations based on the TCI state configurations in LTM DU configurations N+1, N+2, ..., and / or N+M, and includes the new TCI state configurations in the second service DU configuration.

[0207] In some implementations, when CU 172 and S-DU 174A execute procedure 380 with UE 102, the values ​​of ID 1, ..., N in procedure 380 are different from the values ​​of ID 1, ..., N and ID N+1, ..., N+M described for scenario 400. In some implementations, when CU 172 and S-DU 174A execute procedure 380 with UE 102, the values ​​of cell ID 1, ..., N in procedure 380 are different from the values ​​of cell ID 1, ..., N and cell ID N+1, ..., N+M described for scenario 400. In some implementations, when CU 172 and S-DU 174A execute procedure 380 with UE 102, the values ​​of cell index 1, ..., N in procedure 380 are different from the values ​​of cell index 1, ..., N and cell index N+1, ..., N+M described for scenario 400.

[0208] Later, similar to event 324, UE 102 may send at least one measurement report 424 to S-DU 174A. This at least one measurement report (e.g., an L1 measurement report) includes an event ID, a first measurement result for cell 1 of T-DU 174B, and / or a second measurement result for cell 124A. In some implementations, the first measurement result may be or includes RSRP, RSRQ, and / or SINR obtained by UE 102 from a reference signal transmitted on cell 1. Similarly, the second measurement result may be or includes RSRP, RSRQ, and / or SINR obtained by UE 102 from a reference signal transmitted on cell 124A. In some implementations, the event ID, RSRP, RSRQ, and / or SINR are L1 event ID, L1-RSRP, L1-RSRQ, and / or L1-SINR, respectively. Based on the first measurement result and / or the second measurement result, S-DU 174A may send a first LTM command (i.e., LTM command 1) including ID 1 to UE 102, instructing UE 102 to perform a serving cell change to cell 1 of T-DU 174B. In some implementations, the first LTM command includes ID 1 (i.e., LTM ID). In other implementations, the first LTM command includes cell index 1. When UE 102 receives the first LTM command, UE 102 performs a serving cell change to cell 1 from the serving cell according to LTM DU configuration 1. After receiving the first LTM command (e.g., in response to this), UE 102 may or may not perform the random access procedure with T-DU 174B, similar to event 332. Upon receiving the first LTM command or completing random access procedure 432 (e.g., in response to this), UE 102 may communicate with T-DU 174B on the first cell using LTM DU configuration 1 and / or referencing LTM DU configuration 436, and communicate with CU 172 via T-DU 174B, similar to event 336. If a serving cell change occurs in procedure 380, the serving cell may be cell 1 or cell 2 of S-DU 174A. Otherwise, if no serving cell change occurs in procedure 380 or procedure 380 is not executed, the serving cell is cell 124A. If the first LTM command includes LTM ID 1, UE 102 identifies LTM DU configuration 1 and / or cell ID 1 (i.e., cell 1) based on LTM ID 1, as for Figure 3 As described. If the first LTM command includes cell index 1, then UE 102 identifies LTM DU configuration 1, cell ID 1 (i.e., cell 1), and / or LTM ID 1 based on cell index 1, as for... Figure 3As described. Upon receiving the first LTM command or successfully accessing cell 1 (e.g., in response to this), UE 102 applies LTM DU configuration 1 to communicate with T-DU 174B.

[0209] When LTM DU Configuration 1 is activated or the first LTM command 430 is sent, or in response to this, the S-DU 174A may send a DU-to-CU message 429 to the CU 172 indicating that LTM is being performed. In some implementations, the S-DU 174A includes Cell ID 1 or LTM ID 1 in the DU-to-CU message 429 to indicate that the S-DU 174A will activate LTM DU Configuration 1 or trigger an LTM serving cell change. The S-DU 174A may send the DU-to-CU message 429 to the CU 172 before or after sending the LTM command 430. In some implementations, upon or after the CU 172 receives the DU-to-CU message 429, the CU 172 may stop or suspend sending DL data for UE 102 to the S-DU 174A until it receives the DU-to-CU message 434. After receiving DU to CU message 434, CU 172 starts, continues, or resumes sending DL data for UE 102 to T-DU 174B. When or after T-DU 174B detects UE 102 accessing cell 1, T-DU 174B sends DL data to UE 102 via cell 1.

[0210] The resource release procedure 496 can be similar to procedure 396. Alternatively, in the resource release procedure 496, CU 172 can send a CU-to-DU message to S-DU 174A (e.g., UE context release command The S-DU 174A releases the UE context of UE 102 and sends a 440 DU to CU message to CU-172 (e.g., ). UE Context release complete information).

[0211] Events 380, 404, 406, 490, 492, 494, 494, 424, 426, 428, 429, 430, 431, 432, 434, 436, 496, 498, and 456 are in Figure 4 This is collectively referred to as the LTM configuration and / or activation process 480.

[0212] Next reference Figure 5AIn scenario 500A, the second BS 106 performs the MN operation, and the first BS 104 performs the SN operation. SN 104 includes CU 172 and DU 174. Scenario 500A is similar to scenario 300, except that scenario 500A is a DC scenario, while scenario 300 is a single-connection (SC) scenario. MN 106 may include similar... Figure 3 The first BS 104 of CU and DU.

[0213] Initially, UE 102 communicates with MN 106 and SN 104 via DC. In event 502, UE 102 uses the serving DU configuration to communicate with DU 174 on cell 124A and uses the serving CU configuration to communicate with CU 172 via DU 174, similar to event 302. In some alternative implementations, UE 102 does not communicate with CU 172 via DU 174 in event 302. In some implementations, UE 102 may communicate with MN 106 and / or SN 104 via a radio bearer (502 UL PDU and / or DLPDU) via DC, which may include an SRB and / or DRB. MN 106 and / or SN 104 may configure the radio bearer for UE 102. UE 102 communicates with SN 104 via DC on the SCG (i.e., SCG radio resources) configured for communication with UE 102, delivering 502 UL PDUs and / or DL ​​PDUs. UE 102 communicates with MN 106 via DC on the MCG (i.e., MCG radio resources) according to the MN configuration (i.e., MCG configuration). In some implementations, the serving DU configuration is the SN configuration (i.e., SCG configuration). In the MN configuration, MN 106 configures the MCG, which includes at least one serving cell (e.g., cell 126 and / or other cells) operated by MN 106. In the serving DU configuration, SN 106A configures the SCG, which includes at least one serving cell (e.g., cell 124A and / or other cells) operated by SN 104. In some implementations, the MN configuration includes multiple configuration parameters, and UE 102 receives these configuration parameters from MN 106 in one or more RRC messages. Figure 3 As described, the service DU configuration includes multiple configuration parameters. In some implementations, UE 102 receives these configuration parameters from SN 104, for example, via MN 106 and / or on an SRB (e.g., SRB3) configured to exchange RRC messages between UE 102 and SN 104.

[0214] When UE 102 communicates with MN 106 and SN 104 via DC, MN 106 may perform a 580 LTM DU configuration and / or activation procedure with UE 102, similar to procedures 380 and / or 480. In some implementations, when communicating with MN 106 and SN 104 via DC, UE 102 may send at least one measurement report to CU 172 via DU 174 and cell 124A in events 504 and 506, respectively, similar to events 304 and 306. In other implementations, when communicating with MN 106 and SN 104 via DC, UE 102 may send at least one measurement report (505) to MN 106 via cell 126. MN 106 then sends at least one measurement report (507) to CU 172. In some implementations, MN 106 generates at least one SN message including at least one measurement report and sends at least one SN message to CU 172 in event 507. In one implementation, at least one SN message includes RRC transmission Messages and / or SN Modification Request information.

[0215] Upon receiving at least one measurement report (e.g., in response to this) or during communication between SN 104 and UE 102, SN 104 determines to prepare a first cell for UE 102, as for... Figure 3 Events 590, 592, 594, 524, 526, 528, 529, 530, 531, 532, 534, 536, 596, 598, and 556 are similar to events 390, 392, 394, 324, 326, 328, 329, 330, 331, 332, 334, 336, 396, 398, and 356. After receiving the first LTM command 530, sending an acknowledgment 531, or confirming that UE 102 has successfully connected to the first cell 532 or 536, UE 102, operating in DC mode with MN 106 and SN 104, communicates 536 with DU 174 on the first cell according to LTM DU configuration 1 and communicates 536 with CU 172 via DU 174, similar to event 336. Later, DU 174 and / or CU 172 may perform an LTM execution procedure 598 with UE 102, similar to procedure 398 or 498, to command UE 102 to perform a cell change from the first cell to the second cell. As a result of procedure 598, UE 102, operating in DC mode with MN 106 and SN 104, communicates with DU 174 on the second cell 556 according to LTM DU configuration 2 and with CU 172 via DU 174 556, similar to event 356.

[0216] Events 504, 506, 505, 507, 590, 592, 594, 524, 526, 528, 529, 530, 531, 532, 534, 536, 596, 598, and 556 are collectively referred to as LTM DU configuration and / or activation process 581 in Figure 5.

[0217] Next reference Figure 5B Scenario 500B is largely similar to Scenario 500A, the difference being that SN 104 sends RRC reconfiguration messages 517 and 519 to UE 102 via MN 106 and receives RRC reconfiguration completion messages 521 and 523 from UE 102 via MN 106. RRC reconfiguration messages 517 and 519 are similar to RRC reconfiguration messages 316 and 318. RRC reconfiguration completion messages 521 and 523 are similar to RRC reconfiguration messages 320 and 322. In some implementations, SN 104 generates a first SN message including the RRC reconfiguration messages (e.g., ...). SN Modification Requirements information, SN Modification Requirements Message or RRC transmission In event 517, MN 106 sends a first SN message to MN 106. MN 106 generates an MN RRC message including an RRC reconfiguration message and sends the MN RRC message to UE 102. In response, UE 102 generates an MN RRC response message including an RRC reconfiguration completion message and sends the MN RRC response message to MN 106. In some implementations, MN 106 generates a second SN message including an RRC reconfiguration completion message (e.g., ...). SN reconfiguration complete Message or RRC transmission (Message), and in event 523, a second SN message is sent to SN 104. In some implementations, the MN RRC message and the MN RRC response message can be the RRC reconfiguration message and the RRC reconfiguration complete message, respectively.

[0218] Events 504, 506, 505, 507, 590, 592, 594, 517, 519, 521, 523, 524, 526, 528, 529, 530, 531, 532, 534, 536, 596, 598, and 556 are... Figure 5B This is collectively referred to as the LTM DU configuration and / or activation process 582.

[0219] Next reference Figure 6AIn scenario 600A, the second BS 106 operates as the MN and the first BS 104 operates as the SN, similar to scenarios 300-500B. SN 104 includes CU 172, S-DU 174A, and T-DU 174B, similar to the first BS 104 in scenario 400. When UE 102 communicates with MN 106 and SN 104 via DC, MN 106 can perform the 680 LTMDU configuration and / or activation procedure with UE 102, similar to procedures 380 and / or 480. When UE 102 communicates with M-DU 174A and S-DU 174B via DC, CU 172 can perform the 681 LTMDU configuration and / or activation procedure with UE 102 via M-DU 174A or S-DU 174B, similar to procedures 581 or 582.

[0220] Next reference Figure 6B Scenario 600B is similar to scenarios 300 to 500B and 600A, except that SN 104 sends RRC reconfiguration messages 617 and 619 to UE 102 via MN106 and receives RRC reconfiguration completion messages 621 and 623 from UE 102 via MN106.

[0221] Next reference Figure 7A In scenario 700A, the first BS 104 performs MN and SN operations, similar to scenarios 300-600B. The first BS 104 includes CU 172, main DU (M-DU) 174A, and auxiliary DU (S-DU) 174B. Similar to... Figure 3 The first BS 104 or Figures 5A to 6B MN 106, CU 172 operate together with M-DU 174A as MN and are similar Figures 5A to 6B SN 104, CU 172 in the series operate together with S-DU 174B, which is an SN.

[0222] In scenario 700A, UE 102 initially communicates with M-DU 174A and S-DU 174B via DC 702 and with CU 172 via M-DU 174A and S-DU 174B 702. In event 702, UE 102 uses the serving DU configuration to communicate with S-DU 174B on cell 124A and uses the serving CU configuration to communicate with CU 172 via S-DU 174B, similar to event 302. Events 704 and 706 are similar to events 304 and 306. In some implementations, UE 102 may send 705 at least one measurement report to M-DU 174A, similar to event 304. M-DU 174A then sends 707 at least one DU-to-CU message including at least one measurement report to CU 172, similar to event 306. When UE 102 communicates with M-DU 174A and S-DU 174B via DC, CU 172 can perform the 780 LTM DU configuration and / or activation procedure with UE 102 via M-DU 174A, similar to procedure 380.

[0223] Events 704, 706, 705, 707, 790, 792, 794, 724, 726, 728, 729, 730, 731, 732, 734, 736, 796, 798, and 756 are in Figure 7A This is collectively referred to as the LTM configuration and / or activation process 781.

[0224] Next reference Figure 7B Scenario 700B is similar to scenarios 300-600B and 700A, except that CU 172 sends 717 and 719 RRC reconfiguration messages to UE 102 via M-DU 174A and receives 721 and 723 RRC reconfiguration completion messages from UE 102 via M-DU 174A.

[0225] Events 704, 706, 705, 707, 790, 792, 794, 717, 719, 721, 723, 724, 726, 728, 729, 730, 731, 732, 734, 736, 796, 798, and 756 are in Figure 7B This is collectively referred to as the LTM DU configuration and / or activation process 782.

[0226] Next reference Figure 8AIn scenario 800A, the first BS 104 operates as both MN and SN, similar to scenarios 300-700B. The first BS 104 includes CU 172, primary DU (M-DU) 174A, secondary DU (S-DU) 174B, and target secondary DU (T-DU) 174C. CU 172 operates as MN together with M-DU 174A and as SN together with S-DU 174B. When UE 102 communicates with M-DU 174A and S-DU 174B via DC, CU 172 can perform the 880 LTM DU configuration and / or activation procedure with UE 102 via M-DU 174A, similar to procedure 380. When UE 102 communicates with M-DU 174A and S-DU 174B via DC, CU 172 can perform the 881 LTM DU configuration and / or activation procedure with UE 102 via S-DU 174A, similar to procedure 581 or 582.

[0227] Next reference Figure 8B Scenario 800B is similar to scenarios 300-700B and 800A, except that CU 172 sends 817 and 819 RRC reconfiguration messages to UE 102 via M-DU 174A and receives 821 and 823 RRC reconfiguration completion messages from UE 102 via M-DU 174A.

[0228] Next, refer to Figures 9A to 15D This paper discusses several example methods that can be implemented in the RAN node (e.g., BS, DU, or CU) or UE for configuring and / or activating one or more TCI state configurations for LTM candidate cells (i.e., cells used for LTM). For Figures 3 to 8B The description can be applied to Figures 9A to 15D .

[0229] Figure 9AAn example method 900A is illustrated, which can be implemented by a BS (e.g., first BS 104 or 106). Method 900A begins at step 902, in which the BS communicates with the UE via the serving cell using at least one first non-LTM TCI state configuration (e.g., events 302, 402, 502, 602, 702, 802). In step 904, the BS sends the UE an LTM ID, a first LTMDU configuration, and at least one first LTM TCI state configuration, wherein the first LTM DU configuration is an LTM configuration candidate cell, and each of the first LTM TCI state configurations configures a TCI state for that candidate cell (e.g., events 316, 318, 394, 494, 594, 517, 519, 694, 617, 619, 794, 717, 719, 894, 817, 819). In some implementations, the LTM ID identifies both the LTM DU configuration and the first LTM TCI state configuration. In some implementations, the BS includes the LTM ID, the first LTM DU configuration, and the first LTM TCI state configuration in the RRC reconfiguration message and sends this RRC reconfiguration message to the UE. In other implementations, the BS sends the UE a first RRC reconfiguration message including the LTM ID and the first LTM DU configuration, and a second RRC reconfiguration message including the LTM ID and the first LTM TCI state configuration. The BS may do this because the UE or the BS does not support the reception of segmented DL RRC messages.

[0230] In some implementations, the BS includes the LTM DU configuration in the DL RRC message and includes that DL RRC message in a first element (e.g., element 1 above). The BS includes the LTM ID in this first element. In step 904, the BS sends this first element to the UE. In some implementations, the BS includes the first LTM TCI state configuration in this first element. In some implementations, the BS includes this first element in the (first) RRC reconfiguration message. In other implementations, the BS includes the first LTM TCI state configuration in a second element instead of the first element. In such cases, the BS also includes the LTM ID in the second element to indicate the first LTM TCI state configuration associated with the LTM ID. For example, the second element is an addition or modification of the IE (e.g., LTM-ConfigToAddMod IE LTM-Candidate IE LTM- CandidateToAddMod IE or LTM-CandidateConfigToAddMod (IE). In step 904, the BS sends the second element to the UE. In some implementations, the BS includes the second element in the second RRC reconfiguration message.

[0231] In step 906, the BS generates a first LTM TCI state activation / deactivation command (also referred to as an "LTM TCI state command") to activate one or more of the first LTM TCI state configurations. This first LTM TCI state activation / deactivation command includes an LTM ID and at least one first TCI state ID, and each first TCI state ID identifies a corresponding one of the first LTM TCI state configurations (e.g., events 325, 425, 525, 625, 725, 825). In step 908, the BS uses one of the first non-LTM TCI state configurations to send the first LTM TCI state activation / deactivation command (e.g., events 325, 425, 525, 625, 725, 825) to the UE via the serving cell. In step 910, the BS uses the (activated) first LTM TCI state configuration to send one or more reference signals on the candidate cell. In step 912, the BS uses one of the first non-LTM TCI state configurations... In step 914, the BS detects that the UE has accessed a candidate cell (e.g., events 332, 432, 532, 632, 732, 832). In step 916, the BS communicates with the UE via the candidate cell using the LTM DU configuration and the activated LTM TCI state configuration (e.g., events 336, 436, 536, 636, 736, 836). The activated LTM TCI state configuration is the one activated by the LTM command in step 912.

[0232] In some implementations, the UE, in response to an LTM command, performs a contention-based random access procedure with the BS on a candidate cell. During the random access procedure, the UE transmits a random access preamble on the candidate cell. The BS associates this random access preamble with an SSB or SSB index. The BS may include association information in its LTM DU configuration indicating the association between the random access preamble and the SSB (index). The BS transmits the SSB on the candidate cell using its BS transmission beam. The UE receives the SSB from the BS on the candidate cell using its UE reception / receiving beam. The UE may receive and / or measure the SSB before receiving the LTM command. Alternatively, the UE may receive and / or measure the SSB after receiving the LTM command. The UE determines (e.g., selects) the random access preamble based on the SSB. The UE transmits the random access preamble on the candidate cell using a UE transmission beam corresponding to or derived from the UE reception beam. The BS may receive the random access preamble using its BS reception beam. After sending the random access preamble, the UE monitors the PDCCH to receive the random access response. The UE can use the UE receive beam to monitor the PDCCH. In response to receiving the random access preamble, the BS generates a DCI that schedules the PDSCH transmission of the random access response and transmits the DCI to the UE on the PDCCH. The BS can use the BS transmit beam to transmit the DCI on the PDCCH. In some implementations, the BS avoids using the first LTM TCI state configuration to transmit the DCI and PDSCH transmission. The random access response includes a random access preamble ID (or preamble index) identifying the random access preamble, a UL grant, and a timing advance command. The UE adjusts the UL transmission timing according to the timing advance command. The UE transmits a UL PDU (e.g., a MAC PDU) to the BS according to the UL grant and UL transmission timing. The random access response may also include a TAG ID field. The UE may ignore or not use the TAG ID field, or the UE may determine that the TAG ID field is a reserved / unused field, even if the UE supports and / or operates two TA features in the source serving cell or S-DU. The UE can transmit the UL PDU using the UE transmit beam. In some implementations, the UE avoids using the first LTM TCI state configuration to transmit the UL PDU. In some implementations, the UE includes its UE identifier (e.g., C-RNTI) in the UL MAC PDU. In some implementations, after transmitting the UL PDU, the UE monitors the PDCCH according to the first LTM TCI state configuration. After transmitting the UL PDU, the UE can monitor the PDCCH according to the first LTM TCI state configuration, where the PDCCH schedules new UL grants or indicates / confirms DL assignments of the UE identifier.In other implementations, the UE uses the UE receive beam to monitor the PDCCH. The BS receives the UL PDU from the UE according to UL permission. The BS can receive the UL PDU using the BS receive beam. The BS identifies the UE based on the UE identifier. In response to receiving the UE identifier, the BS generates a DCI and a CRC for the DCI, scrambles the CRC with the UE identifier, and transmits the DCI and scrambled CRC to the UE on the PDCCH. In some implementations, the BS transmits the DCI and scrambled CRC using a first LTM TCI state configuration in a first LTM TCI state configuration. The UE receives the DCI and scrambled CRC on the PDCCH using a first LTM TCI state configuration in a first LTM TCI state configuration (i.e., the same LTM TCI state configuration used by the BS to transmit the DCI and scrambled CRC). When the UE receives the scrambled CRC and determines that the (scrambled) CRC is valid, the UE determines that the UE has successfully performed an LTM cell handover to the candidate cell. In some implementations, the DCI schedules PUSCH transmissions. In this case, the UE transmits PUSCH transmissions on the candidate cell. The BS receives PUSCH transmissions on candidate cells based on the DCI. After the BS successfully completes a contention-based random access procedure with the UE, the base station can communicate with the UE using the activated LTM TCI state configuration. Alternatively, after the BS successfully completes a contention-based random access procedure with the UE, the BS communicates with the UE using the BS transmit beam and BS receive beam, instead of the activated LTM TCI state configuration.

[0233] In some implementations, the transmit beam used / derived by the UE or BS for transmission can be referred to as the spatial transmit parameter / filter used / derived by the UE or BS for transmission. In some implementations, the receive beam used / derived by the UE or BS for reception can be referred to as the spatial receive parameter or QCL assumption used / derived by the UE or BS for reception.

[0234] In other implementations, the LTM command includes contention-free random access (CFRA) configuration parameters / fields. CFRA configuration parameters may include a preamble index, a UL / SUL (SUL) indicator, an SSB index, a PRACH mask index, and / or a repetition count. The preamble index indicates the random access preamble. The UE determines the random access preamble based on the preamble index. The UE determines the UL carrier or SUL carrier of the candidate cell based on the UL / SUL indicator to transmit the random access preamble. In some implementations, the LTM DU configuration includes a first plurality of configuration parameters and a second plurality of configuration parameters for the UL carrier and the SUL carrier, respectively. For example, if the UL / SUL indicator indicates a UL carrier, the UE, for example, uses the first plurality of configuration parameters to transmit the random access preamble on the UL carrier of the candidate cell. If the UL / SUL indicator indicates a SUL carrier, the UE, for example, uses the second plurality of configuration parameters to transmit the random access preamble on the SUL carrier of the candidate cell. In some implementations, if the UE determines that the candidate cell does not support the SUL carrier (e.g., the LTM DU configuration does not include configuration parameters for the SUL carrier), the UE can ignore the UL / SUL indicator (or determine that the UL / SUL indicator does not exist) and, for example, use the first plurality of configuration parameters to transmit the random access preamble on the UL carrier of the candidate cell. In other implementations, if the UE determines that the candidate cell does not support the SUL carrier (e.g., the LTM DU configuration does not include configuration parameters for the SUL carrier), the CFRA configuration parameters do not include the UL / SUL indicator, and the UE, for example, uses the first plurality of configuration parameters to transmit the random access preamble on the UL carrier of the candidate cell. In some implementations, the UE determines a path loss reference signal (PL-RS) to determine the UL transmit power used to transmit the random access preamble on the candidate cell. For example, the UE determines the PL-RS based on the SSB (index) indicated in the LTM command. Alternatively, the UE determines the PL-RS based on the first LTM TCI state configuration indicated / activated in the LTM command. In some implementations, the UE receives an SSB indicated by an SSB index from an LTM command from the BS on a candidate cell. The UE can receive this SSB using its UE receive beam. In some implementations, the UE transmits a random access preamble on the candidate cell using a UE transmit beam corresponding to or derived from the UE receive beam. In such cases, the UE uses its UE receive beam to monitor the PDCCH to receive a random access response, as described above in the contention-based random access procedure. For example, the UE can use the UE receive beam configured for receiving an SSB or a first LTM TCI state indicated / activated in an LTM command to monitor the PDCCH to receive a random access response.

[0235] In other implementations, when the UE performs an LTM cell handover to a candidate cell in response to receiving an LTM command, the UE skips the random access procedure and sends a UL transmission (e.g., a PUSCH transmission) to the BS to access the candidate cell. In some implementations, the UE skips the random access procedure on the candidate cell because the UE has already obtained UL synchronization on / with the candidate cell, or the LTM command includes a (valid) timing advance command for the candidate cell. In some implementations, the LTM command includes a timing advance command for the candidate cell to instruct the UE to skip the random access procedure. The UE applies the timing advance command and skips the random access procedure when accessing the candidate cell in response to the LTM command. In other implementations, the LTM command includes an indication to instruct the UE to obtain UL synchronization with the candidate cell. This indication is not a timing advance command. In response to this indication, the UE obtains UL synchronization based on a Reference Signal Time Difference (RSTD) measurement. The BS receives the UL transmission from the UE. In some implementations, the BS includes a configured license configuration in the LTM DU configuration, and the UE sends the UL transmission using the configured license configured by the configured license configuration. In other implementations, the UE receives a dynamic clearance for itself from the BS on the candidate cell and transmits a UL transmission based on the dynamic clearance. In response to receiving the UL transmission, the BS generates a DCI and a CRC for the DCI, scrambles the CRC with the UE identifier, and transmits the DCI and scrambled CRC to the UE on the PDCCH. The DCI schedules either a PUSCH transmission or a PDSCH transmission. In some implementations, the BS uses a first LTM TCI state configuration, such as the one indicated in or derived from the LTM command, to transmit the DCI and scrambled CRC. The UE receives the DCI and scrambled CRC on the PDCCH using a first LTM TCI state configuration (i.e., the same LTM TCI state configuration used by the BS to transmit the DCI and scrambled CRC). When the UE receives the scrambled CRC and determines that the (scrambled) CRC is valid, the UE determines that it has successfully performed an LTM cell handover to the candidate cell. If the DCI schedules a PUSCH transmission, the UE transmits the PUSCH transmission on the candidate cell. The BS receives PUSCH transmissions on candidate cells based on the DCI. If the DCI schedules PDSCH transmissions, the BS sends PDSCH transmissions on candidate cells based on the DCI. The UE receives PDSCH transmissions on candidate cells based on the DCI.

[0236] In some implementations, the LTM ID is an LTM candidate ID or an LTM configuration index. In some implementations, the BS configures the LTM ID as a value of 0, ..., 7. In such cases, the LTM ID is in 3-bit format. In some implementations, the BS sends the candidate cell ID (e.g., PCI) to the UE. In some implementations, the PCI is in 10-bit format. The BS may include the cell ID in the first LTM DU configuration. The BS may include the cell ID in the aforementioned RRC reconfiguration message, the first RRC reconfiguration message, or the second RRC reconfiguration message. In some implementations, the reference signal includes one or more SSBs, one or more CSI-RSs, and / or one or more tracking reference signals. The tracking reference signal may be a CSI-RS used for (time / frequency) tracking or configured with higher-layer parameters. trs-Info The CSI resource is centralized in CSI-RS.

[0237] In some implementations, the LTM TCI state configuration configures the TCI state. In some implementations, the first LTM TCI state configuration includes the LTM TCI state configuration activated by an LTM command with a TCI state ID. In other implementations, the first LTM TCI state configuration does not include the LTM TCI state configuration activated by an LTM command with a TCI state ID. The BS may send the LTM TCI state configuration to the UE before sending the LTM command. For example, the BS may include the LTM TCI state configuration in an RRC reconfiguration message, a first RRC reconfiguration message, or a second RRC reconfiguration message. In another example, the BS sends a third RRC reconfiguration message to the UE that includes the LTM TCI state configuration.

[0238] In some implementations, the BS may send at least one second LTM TCI state configuration to the UE, wherein each second LTM TCI state configuration is as follows: Figure 9B The candidate cell is configured with a TCI state as described in step 905. In some implementations, the BS includes at least one second TCI state ID in the first LTM TCI state activation / deactivation command to activate the second TCI state configuration. Each second TCI state ID identifies a corresponding one in the second LTM TCI state configuration. In other implementations, the BS does not include the second TCI state ID in the first LTM TCI state activation / deactivation command. In some implementations, the BS includes the second TCI state ID in the LTM command. In other implementations, the BS does not include the second TCI state ID in the LTM command.

[0239] In some implementations, each LTM TCI state configuration (e.g., in the first and / or second TCI state configuration) includes a TCI state ID that identifies the LTM TCI state configuration.

[0240] Figure 9B This is a flowchart of example method 900B, which is similar to method 900A, except that method 900B includes steps 905, 918, 920, and 922. In step 905, the BS sends an LTM ID and at least one second LTM TCI state configuration to the UE, wherein each second LTM TCI state configuration configures the TCI state for the candidate cell. In some implementations, the LTM ID identifies the second LTM TCI state configuration. In some implementations, the BS includes the second LTM TCI state configuration in the TCI configuration for the UE. Figure 9A The described RRC reconfiguration message or first RRC reconfiguration message. In other implementations, the BS sends a third RRC reconfiguration message to the UE, including the LTMID and the second LTM TCI state configuration. In some implementations, the BS sends the third RRC reconfiguration message to the UE before sending the LTM command or the first LTM TCI state activation / deactivation command. Next, the method follows steps 906, 908, 910, 912, 914, and 916 discussed previously. Steps 910, 912, 914, and 916 are mandatory in this embodiment.

[0241] In step 918, the BS generates a second LTM TCI state activation / deactivation command to activate a second LTM TCI state configuration. This command includes an LTM ID and at least one second TCI state ID, with each second TCI state ID identifying a corresponding configuration in the second LTM TCI state configuration. In step 920, the BS uses the activated LTM TCI state configuration to send the second LTM TCI state activation / deactivation command to the UE via a candidate cell (e.g., events 336, 436, 536, 636, 736, 836). The activated LTM TCI state configuration is the LTM TCI state configuration activated by the LTM command in step 912. In step 922, the BS uses the second LTM TCI state configuration to communicate with the UE via a candidate cell (e.g., events 336, 436, 536, 636, 736, 836). In some embodiments, the BS may instruct the deactivation of some or all of the first LTM TCI state configurations in the second LTM TCI state activation / deactivation command.

[0242] Figure 9CThis is a flowchart of example method 900C, which is similar to method 900A, except that method 900C includes steps 917, 919, and 921. In step 917, the BS generates a non-LTM TCI state activation / deactivation command to activate at least one second non-LTM TCI state configuration. This non-LTM TCI state activation / deactivation command includes a cell index of a candidate cell and at least one second TCI state ID, and each second TCI state ID identifies a corresponding one of the second non-LTM TCI state configurations (e.g., events 336, 436, 536, 636, 736, 836). In step 919, the BS uses the activated LTM TCI state configuration to send the non-LTM TCI state activation / deactivation command (e.g., events 336, 436, 536, 636, 736, 836) to the UE via the candidate cell. The activated LTM TCI state configuration is the LTM TCI state configuration activated by the LTM command in step 912. In step 921, the BS communicates with the UE via the candidate cell using the second non-LTM TCI state configuration (e.g., events 336, 436, 536, 636, 736, 836).

[0243] In some implementations, the candidate cell's cell index is neither a PCI nor an LTM ID. In some implementations, the cell index is the serving cell index. In some implementations, the BS configures the serving cell index with values ​​0, ..., 31. In such cases, the serving cell index can be in a 5-bit format. In some implementations, the BS uses the cell index to activate or deactivate the candidate cell's TCI state configuration for the UE only when the candidate cell becomes the UE's serving cell. In some implementations, the BS includes the cell index in a second non-LTM TCI state configuration.

[0244] In some implementations, the BS includes the second non-LTM TCI state configuration in the LTM DU configuration. In other implementations, the BS sends the second non-LTM TCI state configuration to the UE via a candidate cell (i.e., the new serving cell). For example, the BS sends an RRC reconfiguration to the UE via a candidate cell (i.e., the new serving cell) that includes the second non-LTM TCI state configuration.

[0245] Figure 9DThis is a flowchart of example method 900D, which is similar to method 900A, except that method 900D includes steps 903, 930, and 907 instead of steps 904 and 906. In step 903, the BS sends the LTM ID, a first LTM DU configuration, a PCI, and at least one first LTM TCI state configuration to the UE. The first LTM DU configuration is an LTM configuration candidate cell, each first LTM TCI state configuration configures a TCI state for that candidate cell, and the PCI is the PCI of that candidate cell. Step 903 is similar to step 904. In some implementations, the LTM ID identifies the LTM DU configuration and the first LTM TCI state configuration. In step 930, the BS determines the candidate cell ID based on the candidate cell's PCI, as discussed in the following paragraph. In step 907, the BS generates a first LTM TCI state activation / deactivation command to activate the first LTM TCI state configuration. The first LTM TCI state activation / deactivation command includes a candidate cell ID and at least one first TCI state ID, and each first TCI state ID identifies a corresponding one in the first LTM TCI state configuration (e.g., events 325, 425, 525, 625, 725, 825).

[0246] In some implementations, the UE and BS use a formula and the PCI of the candidate cell to determine the candidate cell ID. For example, the formula is: Candidate Cell ID = PCI value modulo 2 候选小区ID的比特数 .

[0247] For example, the candidate cell ID is 3 bits, and the PCI is 10 bits. The UE and BS generate the 3-bit candidate cell ID based on the 10-bit PCI and a formula. In this case, the formula is: Candidate Cell ID = PCI value modulo 2 3 .

[0248] Figure 9E This is a flowchart of example method 900E, which is similar to methods 900A, 900B, and 900D, except that method 900E includes step 938 instead of step 918. In step 938, the BS generates a second LTM TCI state activation / deactivation command to activate the second LTM TCI state configuration. This second candidate LTM state activation / deactivation command includes a candidate cell ID and at least one second TCI state ID, and each second TCI state ID identifies a corresponding one in the second LTM TCI state configuration. Step 938 is similar to step 918.

[0249] Figure 9FThis is a flowchart of example method 900F, which is similar to methods 900A, 900C, and 900D. Method 900F begins at step 902, in which the BS communicates with the UE via the serving cell using at least one first non-LTM TCI state configuration (e.g., events 302, 402, 502, 602, 702, 802). In step 903, the BS sends the UE an LTM ID, a first LTM DU configuration, a PCI, and at least one first LTM TCI state configuration, wherein the first LTM DU configuration is an LTM configuration candidate cell, each first LTM TCI state configuration configures a TCI state for that candidate cell, and the PCI is the PCI of that candidate cell. Step 903 is similar to step 904. In some implementations, the LTM ID identifies the LTM DU configuration and the first LTM TCI state configuration. In step 930, the BS determines a candidate cell ID based on the candidate cell's PCI. In step 907, the BS generates a first LTM TCI state activation / deactivation command to activate the first LTM TCI state configuration. The first LTM TCI state activation / deactivation command includes a candidate cell ID and at least one first TCI state ID, and each first TCI state ID identifies a corresponding one in the first LTM TCI state configuration (e.g., events 325, 425, 525, 625, 725, 825).

[0250] In some implementations, the UE and BS use a formula and the PCI of the candidate cell to determine the candidate cell ID. For example, the formula is: Candidate Cell ID = PCI value modulo 2 候选小区ID的比特数 For example, the candidate cell ID is 3 bits, and the PCI is 10 bits. The UE and BS generate the 3-bit candidate cell ID based on the 10-bit PCI and a formula. In this case, the formula is: Candidate Cell ID = PCI value modulo 2 3 .

[0251] Then proceed with steps 910, 912, 914, and 916, which are similar to those discussed above. Figure 9AThe same steps are followed. Next, in step 917, the BS generates a non-LTM TCI state activation / deactivation command to activate at least one second non-LTM TCI state configuration, wherein the non-LTM TCI state activation / deactivation command includes a cell index of a candidate cell and at least one second TCI state ID, and each second TCI state ID identifies a corresponding one of the second non-LTM TCI state configurations (e.g., events 336, 436, 536, 636, 736, 836). In step 919, the BS uses the activated LTM TCI state configuration to send the non-LTM TCI state activation / deactivation command (e.g., events 336, 436, 536, 636, 736, 836) to the UE via the candidate cell. The activated LTM TCI state configuration is the LTM TCI state configuration activated by the LTM command in step 912. In step 921, the BS communicates with the UE via the candidate cell using the second non-LTM TCI state configuration (e.g., events 336, 436, 536, 636, 736, 836).

[0252] Figure 9G This is a flowchart of example method 900G, which is similar to methods 900A and 900D, except that method 900G includes step 944 instead of steps 904 and 930. In step 944, the BS sends the LTM ID, candidate cell ID, PCI, first LTM DU configuration, and at least one first LTM TCI state configuration to the UE, wherein the first LTM DU configuration is an LTM configuration candidate cell, each first LTM TCI state configuration configures a TCI state for that candidate cell, and the PCI is the PCI of that candidate cell. Step 944 is similar to step 904. In some implementations, the LTM ID identifies the LTM DU configuration, and the candidate cell ID identifies the first LTM TCI state configuration. In one embodiment, the candidate cell ID is calculated based on the PCI, as discussed above regarding step 930. In another embodiment, the candidate cell ID is not calculated based on the PCI. For example, the candidate cell ID is derived from or set to the LTM ID.

[0253] Figure 9H This is a flowchart of example method 900H, which includes the steps of methods 900A, 900B, 900D, 900E, and 900G, arranged in different ways.

[0254] Figure 9I This is a flowchart of example method 900I, which includes the steps of methods 900A, 900C, 900D, 900F, and 900G, arranged in different ways.

[0255] Figure 10AExample method 1000A is shown, which can be communicated by a serving DU or a source DU (e.g., ) with the UE and CU. Figures 3 to 8B The implementation is carried out using DU 174, M-DU 174A, or S-DU 174A. The term "S-DU" is used to denote either the service DU or the source DU.

[0256] Method 1000A begins at step 1002, in which the S-DU communicates with the UE via the serving cell using at least one first non-LTM TCI state configuration (e.g., events 302, 402, 502, 602, 702, 802). In step 1004, the S-DU receives a first CU-DU message from the CU requesting the configuration of a candidate cell for LTM for the UE (e.g., events 308, 390, 590, 790). In step 1006, the S-DU receives a second CU-DU message from the CU, which includes an LTM ID for identifying the LTM-related configuration of the candidate cell (e.g., events 308, 390, 312, 392, 590, 592, 790, 792). In some implementations, the first CU-DU message and the second CU-DU message are combined into a single CU-DU message. In some implementations, the LTM ID is the IE of the interface protocol. For example, the interface protocol is the F1 Application Protocol (F1AP). In other implementations, the CU includes the LTM ID in the Interface Protocol IE and then includes that IE in the second CU-DU message. For example, the interface protocol is F1AP. In yet another embodiment, the CU includes the LTM ID in the RRC IE and then includes that RRC IE in the second CU-DU message. For example, the RRC IE is the LTM-CSI-ResourceConfig IE.

[0257] In step 1008, the S-DU generates an LTM DU configuration for the UE, wherein the LTM DU configuration is an LTM configuration candidate cell (e.g., events 310, 390, 590, 790). In some implementations, the S-DU associates the LTM ID with the LTM DU configuration. In some implementations, the S-DU associates the LTM DU configuration and the LTM ID with the cell ID (e.g., CGI) of the candidate cell. In step 1010, the S-DU generates at least one first LTM TCI state configuration and associates the LTM ID with the first LTM TCI state configuration, wherein each first LTM TCI state configuration is a TCI state configuration for the candidate cell (e.g., events 310, 390, 312, 392, 590, 592, 790, 792). In step 1012, the S-DU sends a first DU-to-CU message including the LTM DU configuration to the CU (e.g., events 310, 390, 590, 790). In step 1014, the S-DU sends a second DU-CU message to the CU, including the first LTM TCI state configuration (e.g., events 310, 390, 312, 392, 590, 592, 790, 792). In step 1016, the process proceeds as previously discussed in steps 906 and 908. In step 1018, the process proceeds as previously discussed in steps 912, 914, and 916.

[0258] against Figures 9A to 9C The described examples and implementations can be applied to Figure 10A .

[0259] Figure 10B This is a flowchart of example method 1000B, which is similar to method 1000A, except that method 1000B includes steps 1009, 1011, and 1017 instead of steps 1010 and 1016. In step 1009, the S-DU generates at least one first LTM TCI state configuration, wherein each first LTM TCI state configuration configures the TCI state for the candidate cell. In step 1011, the S-DU associates the first LTM TCI state configuration with the PCI of the candidate cell. In step 1017, the S-DU performs the actions described in steps 930, 907, and 908. Figures 9A to 9F The described examples and implementations can be applied to Figure 10B .

[0260] Figure 10CThis is a flowchart of example method 1000C, which is similar to methods 1000A and 1000B, except that method 1000C includes steps 1030 and 1015 instead of steps 1008, 1016, and 1017. In step 1030, the S-DU generates at least one first LTM TCI state configuration and a candidate cell ID, wherein each first LTM TCI state configuration configures the TCI state for that candidate cell, and the candidate cell ID identifies the first LTM TCI state configuration. In step 1015, the S-DU performs the actions described in steps 907 and 908. For... Figures 9A to 9I The described examples and implementations can be applied to Figure 10C .

[0261] Figure 11A Example method 1100A is shown, which can be generated by candidate DU (C-DU) (e.g., Figure 4 , Figure 6A and Figure 6B T-DU 174B or Figure 8A and Figure 8B The T-DU 174C is implemented in this system.

[0262] Method 1100A begins at step 1104, in which the C-DU receives a first CU-DU message from the CU to request configuration of a candidate cell for LTM for the UE. In some implementations, the first CU-DU message is a CU-DU message of procedure 490, 690, or 890. At step 1106, the C-DU receives a second CU-DU message from the CU, which includes an LTM ID for identifying the LTM-related configuration of the candidate cell. In some implementations, the second CU-DU message is a CU-DU message of procedure 490, 492, 690, 692, 890, or 892. In some implementations, the first and second CU-DU messages are combined into a single CU-DU message.

[0263] In step 1108, the C-DU generates an LTM DU configuration for the UE, wherein the LTM DU configuration is an LTM configuration candidate cell. In some implementations, the C-DU associates the LTM ID with the LTM DU configuration. In some implementations, the C-DU associates the LTM DU configuration and the LTM ID with the cell ID (e.g., CGI) of the candidate cell. In step 1110, the C-DU generates at least one first LTM TCI state configuration for the UE and associates the LTM ID with the first LTM TCI state configuration, wherein each first LTM TCI state configuration is a TCI state configuration for the candidate cell. In step 1112, the C-DU sends a first DU-to-CU message including the LTM DU configuration to the CU. In some implementations, the first DU-to-CU message is the DU-to-CU message of procedure 490, 690, or 890. In step 1114, the C-DU sends a second DU-to-CU message including the first LTM TCI state configuration to the CU. In some implementations, the second DU to CU message is a DU to CU message of procedures 490, 492, 690, 692, 890, or 892. In some implementations, the first DU to CU message and the second DU to CU message are combined into a single DU to CU message.

[0264] In step 1116, the C-DU receives a third CU-to-DU message from the CU, which includes at least one first TCI state ID, wherein each first TCI state ID identifies a corresponding one in the first LTM TCI state configuration. In step 1118, the C-DU performs the actions described in steps 914 and 916. Based on the first TCI state ID, the C-DU identifies at least one corresponding LTM TCI state configuration. In some implementations, the third CU-to-DU message includes the cell ID (e.g., CGI) of the candidate cell. Based on the first TCI state ID and the cell ID, the C-DU identifies at least one corresponding LTM TCI state configuration associated with the candidate cell. In some implementations, the third CU-to-DU message notifies the UE to perform or be performing an LTM cell handover to the candidate cell. In other implementations, the third CU-to-DU message notifies the UE that an LTM cell handover to the candidate cell has been triggered or has been triggered. In some implementations, the third CU-to-DU message is an LTM cell change notification message.

[0265] against Figures 9A to 9C and Figure 10A The described examples and implementations can be applied to Figure 11A .

[0266] Figure 11BThis is a flowchart of example method 1100B, which is similar to method 1000A, except that method 1100B includes steps 1130 and 1113 instead of steps 1110 and 1114. In step 1130, the C-DU generates at least one first LTM TCI state configuration and candidate cell ID for the UE, and associates the LTM ID with the first LTM TCI state configuration. Each first LTM TCI state configuration configures the TCI state for that candidate cell, and the candidate cell ID identifies the first LTM TCI state configuration. In step 1113, the C-DU sends a second DU-CU message to the CU, including the first LTM TCI state configuration and the candidate cell ID. Figures 9A to 9C , Figure 10A as well as Figures 9G to 9I The described examples and implementations can be applied to Figure 11B .

[0267] Figure 12A Example method 1200A is shown, which can be communicated by a serving DU or a source DU (e.g., ) with the UE and CU. Figures 3 to 8B The implementation is carried out using DU 174, M-DU 174A, or S-174A. The term "S-DU" is used to denote either the service DU or the source DU.

[0268] Method 1200A begins at step 1202, in which the S-DU communicates with the UE via the serving cell using at least one first non-LTM TCI state configuration (e.g., events 402, 602, 802). In step 1204, the S-DU receives a first CU-DU message from the CU, which includes an LTM ID for identifying the LTM-related configuration of the candidate cell (e.g., events 460, 412, 488, 493, 688, 693, 888, 893). In step 1206, the S-DU receives a second CU-DU message from the CU, which includes at least one first LTM TCI state configuration for the UE, wherein each first LTM TCI state configuration configures a TCI state for the candidate cell (e.g., events 460, 412, 488, 493, 688, 693, 888, 893). In some implementations, the first CU-DU message and the second CU-DU message are combined into a single CU-DU message. In step 1208, the S-DU performs the actions described in steps 906 and 908. In step 1210, the S-DU performs the actions described in step 912.

[0269] In some implementations, the CU is derived from... Figure 11A The described C-DU receives the first LTM TCI state configuration. (For...) Figures 9A to 9C and Figure 11AThe described examples and implementations can be applied to Figure 12A .

[0270] Figure 12B This is a flowchart of example method 1200B, which is similar to method 1200A, except that method 1200B includes step 1209 instead of step 1208. In step 1209, the S-DU performs the actions described in steps 930, 907, and 908. Figures 9A to 9F The described examples and implementations can be applied to Figure 12B .

[0271] In some implementations, the second CU-DU message includes the PCI of the candidate cell. In other implementations, the second CU-DU message includes the CGI of the candidate cell, and the S-DU determines the PCI based on the CGI.

[0272] Figure 12C This is a flowchart of example method 1200C, which is similar to methods 1200A and 1200B, except that method 1200C includes steps 1205 and 1207 instead of steps 1206, 1208, and 1209. In step 1205, the S-DU receives a second CU-DU message from the CU, which includes at least one first LTM TCI state configuration and a candidate cell ID for the UE, wherein each first LTM TCI state configuration configures the TCI state for the candidate cell, and the candidate cell ID identifies the first LTM TCI state configuration. In step 1207, the S-DU performs the actions described in steps 907 and 908. Figures 9A to 9I The described examples and implementations can be applied to Figure 12C .

[0273] Figure 13A Example method 1300A is shown, which can be generated by a CU (e.g., Figure 4 , Figure 6A , Figure 6B , Figure 8A and Figure 8B The CU 172 implementation is used to configure and / or activate one or more LTM TCI state configurations before and / or after LTM cell handover for use with the UE (e.g., Figure 4 , Figure 6A , Figure 6B , Figure 8A and Figure 8B Communication with UE 102 in the system.

[0274] Method 1300A begins at step 1302, in which the CU sends a first CU-DU message to a first DU to request configuration of candidate cells (e.g., events) for the UE for LTM. In some implementations, the first CU-DU message is a CU-DU message of procedure 490, 690, or 890. In step 1304, the CU sends a second CU-DU message to the first DU, which includes an LTM ID for identifying the LTM-related configuration of the candidate cell. In some implementations, the second CU-DU message is a CU-DU message of procedure 490, 492, 690, 692, 890, or 892. In some implementations, the first CU-DU message and the second CU-DU message are combined into a single CU-DU message.

[0275] In step 1306, the CU receives a first DU-to-CU message from the first DU, including an LTM DU configuration, and associates the LTM ID with the LTM DU configuration. In some implementations, the first DU-to-CU message is a DU-to-CU message of procedure 490, 690, or 890. In some implementations, the CU associates the LTM ID with an element including the LTM DU configuration, as described above. In step 1308, the CU receives a second DU-to-CU message from the first DU, including at least one first LTM TCI state configuration, wherein each first LTM TCI state configuration configures the TCI state for the candidate cell. In some implementations, the second DU-to-CU message is a DU-to-CU message of procedure 490, 492, 690, 692, 890, or 892. In some implementations, the first DU-to-CU message and the second DU-to-CU message are combined into a single DU-to-CU message. In step 1310, the CU associates the LTM ID with the first LTM TCI state configuration.

[0276] In step 1312, the CU sends a third CU-DU message including the LTM ID to the second DU (e.g., events 412, 493, 693, 893). In step 1314, the CU sends a fourth CU-DU message including the candidate cell ID and the first LTM TCI state configuration to the second DU (e.g., events 412, 493, 693, 893). In some implementations, the third and fourth CU-DU messages are combined into a single CU-DU message. In step 1316, the CU sends a first RRC message including the LTM ID and LTM DU configuration to the UE via the RAN node (e.g., events 494, 694, 617, 619, 894, 817, 819). In step 1318, the CU sends a second RRC message including the LTM ID and the first LTM TCI state configuration to the UE via the RAN node (e.g., events 494, 694, 617, 619, 894, 817, 819).

[0277] In some implementations, one of the first and second DUs is an S-DU, and the other is a C-DU. In some implementations, the RAN node is a BS or a DU. This DU can be a serving / source DU, a primary DU, or a secondary DU. (For...) Figures 9A to 9F , Figure 10A , Figure 10B , Figure 11A , Figure 12A and Figure 12B The described examples and implementations can be applied to Figure 13A .

[0278] Figure 13B This is a flowchart of example method 1300B, which is similar to method 1300A, except that method 1300B includes steps 1309, 1313, and 1319 instead of steps 1308, 1314, and 1318. In step 1309, the CU receives a second DU-to-CU message from a first DU, including at least one first LTM TCI state configuration and a candidate cell ID, wherein each first LTM TCI state configuration configures the TCI state for the candidate cell, and the candidate cell ID identifies the first LTM TCI state configuration. In step 1313, the CU sends a fourth CU-to-DU message to the second DU, which includes the candidate cell's CGI, the first LTM TCI state configuration, and the candidate cell ID. In step 1319, the CU sends a second RRC message to the UE via the RAN node, including the LTM ID, the first LTM TCI state configuration, and the candidate cell ID.

[0279] against Figures 9G to 9I , Figure 10C , Figure 11B and Figure 12CThe described examples and implementations can be applied to Figure 13B .

[0280] Figure 14A Example method 1400A is shown, which can be used by a UE (e.g., Figures 3 to 8BThe method 1400A is implemented in UE 102 for configuring and activating LTM TCI states. Method 1400A begins at step 1402, in which the UE communicates with the RAN via the serving cell using at least one first non-LTM TCI state configuration. In step 1404, the UE receives from the RAN an LTM ID, a first LTMDU configuration, and at least one first LTM TCI state configuration, wherein the first LTM DU configuration is an LTM configuration candidate cell, and each first LTM TCI state configuration configures a TCI state for that candidate cell (e.g., events 316, 318, 394, 494, 594, 517, 519, 694, 617, 619, 794, 717, 719, 894, 817, 819). In some implementations, the LTM ID identifies the LTM DU configuration and the first LTM TCI state configuration. In step 1406, the UE receives a first LTM TCI state activation / deactivation command from the RAN via the serving cell using a first non-LTM TCI state configuration. This first LTM TCI state activation / deactivation command includes an LTM ID and at least one first TCI state ID to activate the first LTM TCI state configuration. Each first TCI state ID identifies a corresponding one of the first LTM TCI state configurations (e.g., events 325, 425, 525, 625, 725, 825). In step 1408, the UE identifies the first LTM TCI state configuration based on the LTM ID and first TCI state ID included in the first TCI state activation / deactivation command. In step 1409, the UE activates the first LTM TCI state configuration in response to the first TCI state activation / deactivation command. In step 1410, the UE receives one or more reference signals on the candidate cell using the first LTM TCI state configuration. In step 1412, the UE receives an LTM command from the RAN via the serving cell using a first non-LTM TCI state configuration, wherein the LTM command includes an LTM ID and / or a TCI state ID, instructing the UE to perform an LTM cell handover and activate the TCI state configuration identified by the TCI state ID (e.g., events 330, 430, 530, 630, 730, 830). In step 1414, the UE accesses the candidate cell in response to receiving the LTM command (e.g., events 332, 432, 532, 632, 732, 832). In step 1416, the UE communicates with the RAN via the candidate cell using the activated LTM TCI state configuration and LTM DU configuration (e.g., events 336, 436, 536, 636, 736, 836).

[0281] Figure 14A The UE and RAN described in the text can be Figure 9AThe UE and BS described in the document. (Targeting...) Figure 9A The described examples and implementations can be applied to Figure 14A .

[0282] Figure 14B This is a flowchart of example method 1400B, which is similar to method 1400A, except that method 1400B includes steps 1405, 1418, 1420, 1422, and 1424. In step 1405, the UE receives an LTM ID and at least one second LTM TCI state configuration from the RAN, wherein a first LTM DU is configured as an LTM configuration candidate cell, and each second LTM TCI state configuration configures a TCI state for that candidate cell. In step 1418, the UE uses the activated LTM TCI state configuration to receive a second LTM TCI state activation / deactivation command from the RAN via the candidate cell, wherein the second LTM TCI state activation / deactivation command includes an LTM ID and at least one second TCI state ID to activate the second LTM TCI state configuration, and each second TCI state ID identifies a corresponding one of the second LTM TCI state configurations. In step 1420, the UE identifies the second LTM TCI state configuration based on the LTM ID and the second TCI state ID included in the second TCI state activation / deactivation command. In step 1422, the UE responds to the second TCI state activation / deactivation command and activates the second LTM TCI state configuration. In step 1424, the UE uses the activated second LTM TCI state configuration to communicate with the RAN via the candidate cell.

[0283] Figure 14B The UE and RAN described in the text can be Figure 9B The UE and BS described in the document. (Targeting...) Figures 9A to 9B The described examples and implementations can be applied to Figure 14B .

[0284] Figure 14C This is a flowchart of example method 1400C, which is similar to methods 1400A and 1400B, except that method 1400C includes steps 1417, 1419, and 1423. In step 1417, the UE uses the activated LTM TCI state configuration to receive a non-LTM TCI state activation / deactivation command from the RAN via a candidate cell. This non-LTM TCI state activation / deactivation command activates at least one second non-LTM TCI state configuration and includes the cell ID of the candidate cell and at least one second TCI state ID, with each second TCI state ID identifying a corresponding one of the second non-LTM TCI state configurations.

[0285] Figure 14CThe UE and RAN described in the text can be Figure 9C The UE and BS described in the document. (Targeting...) Figures 9A to 9C The described examples and implementations can be applied to Figure 14C .

[0286] Figure 14D This is a flowchart of example method 1400D, which is similar to method 1400A, except that method 1400D includes steps 1403, 1430, 1407, and 1440 instead of steps 1404 and 1406. In step 1403, the UE receives an LTM ID, a first LTM DU configuration, a PCI, and at least one first LTM TCI state configuration from the RAN. The first LTM DU configuration is an LTM configuration candidate cell, each first LTM TCI state configuration configures a TCI state for that candidate cell, and the PCI is the PCI of that candidate cell. In some implementations, the LTM ID identifies the LTM DU configuration and the first LTM TCI state configuration. In step 1430, the UE determines the candidate cell ID based on the PCI. In step 1407, the UE receives a first LTM TCI state activation / deactivation command from the RAN via the serving cell using one of the first non-LTM TCI state configurations. This first LTM TCI state activation / deactivation command includes a candidate cell ID and at least one first TCI state ID to activate the first LTM TCI state configuration, and each first TCI state ID identifies a corresponding one of the first LTM TCI state configurations. In step 1440, the UE identifies the first LTM TCI state configuration based on the candidate cell ID and the first TCI state ID included in the first TCI state activation / deactivation command.

[0287] Figure 14D The UE and RAN described in the text can be Figure 9D The UE and BS described in the document. (Targeting...) Figures 9A to 9D The described examples and implementations can be applied to Figure 14D .

[0288] Figure 14EThis is a flowchart of example method 1400E, which is similar to methods 1400A, 1400B, and 1400D, except that method 1400E includes steps 1438 and 1421 instead of step 1418. In step 1438, the UE receives a second LTM TCI state activation / deactivation command from the RAN via a candidate cell using the activated LTM TCI state configuration. This second LTM TCI state activation / deactivation command includes a candidate cell ID and at least one second TCI state ID to activate the second LTM TCI state configuration, and each second TCI state ID identifies a corresponding one in the second LTM TCI state configuration. In step 1421, the UE identifies the second LTM TCI state configuration based on the candidate cell ID and the second TCI state ID included in the second TCI state activation / deactivation command.

[0289] Figure 14E The UE and RAN described in the text can be Figure 9E The UE and BS described in the document. (Targeting...) Figures 9A to 9E The described examples and implementations can be applied to Figure 14E .

[0290] Figure 14F This is a flowchart of example method 1400F, which includes steps from methods 1400A, 1400C, and 1400D, arranged in different orders. Figure 14F The UE and RAN described in the text can be Figure 9F The UE and BS described in the document. (Targeting...) Figures 9A to 9F The described examples and implementations can be applied to Figure 14F .

[0291] Figure 14G This is a flowchart of example method 1400G, which is similar to methods 1400A and 1400D, except that method 1400G includes step 1444 instead of steps 1404 and 1430. In step 1444, the UE receives from the RAN an LTM ID, a candidate cell ID, a PCI, a first LTM DU configuration, and at least one first LTM TCI state configuration, wherein the first LTM DU configuration is an LTM configuration candidate cell, each first LTM TCI state configuration configures a TCI state for that candidate cell, and the PCI is the PCI of that candidate cell. Step 1444 is similar to step 1404. Figure 14G The UE and RAN described in the text can be Figure 9G The UE and BS described in the document. (Targeting...) Figures 9A to 9G The described examples and implementations can be applied to Figure 14G .

[0292] Figure 14HThis is a flowchart of example method 1400H, which includes steps from methods 1400A, 1400B, 1400D, 1400E, and 1400G, but arranged in a different order. Figure 14H The UE and RAN described in the text can be Figure 9H The UE and BS described in the document. (Targeting...) Figures 9A to 9H The described examples and implementations can be applied to Figure 14H .

[0293] Figure 14I This is a flowchart of example method 1400H, which includes steps from methods 1400A, 1400C, 1400D, 1400F, and 1400G, but arranged in a different order. Figure 14I The UE and RAN described in the text can be Figure 9I The UE and BS described in the document. (Targeting...) Figures 9A to 9I The described examples and implementations can be applied to Figure 14I .

[0294] Figure 15A Example method 1500A is shown, which can be used by a UE (e.g., Figures 3 to 8BThe method 1500A is implemented by UE 102 for configuring and activating LTM TCI states. Method 1500A begins at step 1502, in which the UE receives from the RAN an LTMID, an LTM DU configuration, and at least one LTM TCI state configuration, wherein the LTM DU configuration is an LTM configuration candidate cell, each LTM TCI state configuration configures a TCI state for that candidate cell, and the LTM ID identifies the LTM DU configuration (e.g., events 316, 318, 394, 494, 594, 517, 519, 694, 617, 619, 794, 717, 719, 894, 817, 819). In an optional step 1504, the UE receives an LTM TCI state activation / deactivation command from the RAN via the serving cell, wherein the LTM TCI state activation / deactivation command activates the LTM TCI state configuration (e.g., events 325, 425, 525, 625, 725, 825). In optional step 1506, the UE activates the LTM TCI state configuration in response to the LTM TCI state activation / deactivation command. In step 1508, the UE determines whether the candidate cell is the serving cell. If the UE determines in step 1508 that the candidate cell is the serving cell, the process proceeds to step 1510. In step 1510, the UE uses one of the LTM TCI state configurations to receive at least one DL transmission from the RAN and / or send at least one UL transmission to the RAN via the serving cell (e.g., events 336, 436, 536, 636, 736, 836). Otherwise, if the UE determines in step 1508 that the candidate cell is not the serving cell, the process proceeds to step 1512. In step 1512, the UE avoids using the LTM TCI state configuration to receive DL transmissions and / or send UL transmissions.

[0295] Figure 15B This is a flowchart of example method 1500B, which is similar to method 1500A, except that method 1500B includes step 1514 instead of step 1510, and steps 1504 and 1506 are not optional. If the UE determines at 1508 that the candidate cell is the serving cell, the process proceeds to step 1512. Otherwise, if the UE determines at 1508 that the candidate cell is not the serving cell, the process proceeds to step 1514. In step 1514, the UE performs the actions described in steps 1410, 1412, 1414, and 1416 of the previous method.

[0296] Figure 15CThis is a flowchart of example method 1500C, which includes steps from methods 1500A and 1500B, arranged in a different order. If the UE determines that candidate cell 1508 is not the serving cell, the process proceeds to step 1506. Then, the process can proceed to step 1514. Otherwise, the process proceeds to step 1512 discussed above.

[0297] Figure 15D This is a flowchart of example method 1500D, which is similar to methods 1500A and 1500B, except that method 1500D includes steps 1507, 1509, and 1511 instead of steps 1508 and 1510. In step 1507, the UE receives an LTM command from the RAN, which instructs an LTM cell handover to a candidate cell (e.g., events 330, 430, 530, 630, 730, 830). In step 1509, the UE determines whether the LTM command includes a first TCI state ID to activate a TCI state configuration in the TCI state configuration. If the UE determines in step 1509 that the LTM command includes a TCI state ID, the process proceeds to step 1511. In step 1511, the UE uses the LTM TCI state configuration identified by the TCI state ID to receive at least one DL transmission from the RAN via the candidate cell and / or send at least one UL transmission to the RAN. Otherwise, if the UE determines at step 1509 that the LTM command does not include the TCI status ID, the process proceeds to step 1512.

[0298] against Figures 9A to 9I and Figures 14A to 14I The described examples and implementations can be applied to Figures 15A to 15D .

[0299] The following description applies to the embodiments discussed above. A description of one of the above figures may apply to another of the above figures. The examples, implementations, and methods described above may be combined unless otherwise specified. The events or steps described above may be optional or omitted, especially if the step is shown in dashed lines. In some implementations, “message” is used and may be replaced by “information element (IE)”, and vice versa. In some implementations, “IE” is used and may be replaced by “field”, and vice versa. In some implementations, “configuration” may be replaced by “configuration” or “configuration parameter”, and vice versa. In some implementations, “LTM command” may be replaced by “serving cell change command”, “Layer 1 / Layer 2 LTM cell handover command”, “lower layer handover command”, or “lower layer serving cell change command”. In some implementations, “some” means “one or more”. In some implementations, “at least one” means “one or more”. In some implementations, “cell group configuration” may be used instead of “DU configuration”. In some implementations, "Serving Cell Index," "LTM Cell Index," "Special Cell (SpCell) Index," "PCell Index," or "PSCell Index" can be used instead of "Cell Index." In some implementations, "Serving" can be replaced with "Source." In some implementations, "Measurement Report" can be replaced with "Measurement Result." In some implementations, "Early TA Acquisition" can be replaced with "Early UL Timed Synchronization" or "Early UL Synchronization." In some implementations, "Early TA Acquisition on Candidate Cells" can be replaced with "Early UL Timed Synchronization with Candidate Cells" or "Early UL Synchronization with Candidate Cells."

[0300] The user device that implements the technology described in this document (e.g., UE 102) can be any suitable device capable of wireless communication, such as a smartphone, tablet computer, laptop computer, mobile game console, point-of-sale (POS) terminal, health monitoring device, drone, camera, media streaming dongle or other personal media device, wearable device such as a smartwatch, wireless hotspot, femtocell, or broadband router. Furthermore, in some cases, the user device may be embedded in an electronic system such as a vehicle's main unit or an advanced driver assistance system (ADAS). Even further, the user device may operate as an Internet of Things (IoT) device or a mobile internet device (MID). Depending on the type, the user device may include one or more general-purpose processors, computer-readable storage, a user interface, one or more network interfaces, one or more sensors, etc.

[0301] Some embodiments described in this document include logic or multiple components or modules. A module can be a software module (e.g., code or machine-readable instructions stored on a non-transitory machine-readable medium) or a hardware module. A hardware module is a tangible unit capable of performing certain operations and can be configured or arranged in a certain way. A hardware module may include a dedicated circuit system or logic that is persistently configured (e.g., as a dedicated processor, such as a field-programmable gate array (FPGA) or application-specific integrated circuit (ASIC), digital signal processor (DSP), etc.) to perform certain operations. A hardware module may also include programmable logic or circuit systems that are temporarily configured by software to perform certain operations (e.g., as encompassed within a general-purpose processor or other programmable processor). The decision to implement a hardware module in a dedicated and persistently configured circuit system or in a temporarily configured circuit system (e.g., configured by software) may be driven by cost and time considerations.

[0302] When implemented in software, this technology can be provided as part of an operating system, a library used by multiple applications, or a specific software application. The software can be executed by one or more general-purpose processors or one or more dedicated processors.

[0303] Upon reading this document, those skilled in the art will appreciate the additional and alternative structural and functional designs for handling mobility between BSs through the principles disclosed herein. Therefore, while specific embodiments and applications have been shown and described, it should be understood that the disclosed embodiments are not limited to the precise constructions and components disclosed herein. Various modifications, alterations, and variations that will be apparent to those skilled in the art may be made to the arrangement, operation, and details of the methods and apparatus disclosed herein without departing from the spirit and scope defined in the appended claims.

Claims

1. A method (900A to 900I) for wireless communication performed by a base station BS (104) configured for low-level triggering mobility LTM, the method comprising: The LTM ID, the first LTM Distributed Unit (DU) configuration, and one or more first LTM Transport Configuration Indicators (TCI) state configurations are sent to the User Equipment (UE) (102) via the serving cell (124A), wherein each of the LTM ID, the first LTM DU configuration, and the one or more LTM TCI state configurations is associated with the candidate cell (124B). as well as A first LTM TCI state command is sent via the serving cell (908) to activate a first LTM TCI state configuration in one or more first LTM TCI state configurations. The first LTM TCI state command includes the LTM ID and at least one first TCI state ID, and the first TCI state ID identifies a selected first LTM TCI state configuration in one or more first LTM TCI state configurations.

2. The method as described in claim 1, wherein, The sending of the LTM ID, the first LTM DU configuration, and the one or more first LTM TCI state configurations, as well as the sending of the first LTM TCI state command, employ at least one first non-LTM TCI state configuration.

3. The method as described in any one of claims 1 or 2, wherein, Sending the LTM ID, the first LTM DU configuration, and the one or more first LTM TCI state configurations includes sending a second LTM TCI state configuration. The method further includes: The second LTM TCI state command is sent via the candidate cell using the first LTM TCI state configuration to activate the second LTM TCI state configuration.

4. The method of any one of claims 1 or 2, further comprising: Through the candidate cell, a non-LTM TCI state command is sent using the first LTM TCI state configuration to activate the second non-LTM TCI state configuration. The non-LTM TCI state command includes the cell index of the candidate cell and at least one second TCI state ID, wherein the second TCI state ID identifies a specific second non-LTM TCI state configuration.

5. The method as described in any one of claims 1 or 2, wherein, Sending the LTM ID, the first LTM DU configuration, and the one or more first LTM TCI state configurations further includes sending the Physical Cell Identifier (PCI) of the candidate cell.

6. The method of claim 5, further comprising: Based on the PCI, candidate cell IDs (930) are determined. The first LTM TCI status command includes the candidate cell ID.

7. The method of claim 5, further comprising: Send the LTM ID and at least one second LTM TCI state configuration to the UE, wherein the second LTM TCI state configuration is the candidate cell configured TCI state.

8. The method of claim 7, further comprising: Send a second LTM TCI status command to activate the at least one second LTM TCI status configuration, the second LTM TCI status command including the candidate cell ID and at least one second TCI status ID.

9. The method of claim 5, further comprising: Via the candidate cell, a non-LTM TCI state command is sent to the UE using the LTM TCI state configuration to activate at least one second non-LTM TCI state configuration. The non-LTM TCI state command includes the cell index of the candidate cell and at least one second TCI state ID, wherein the second TCI state ID identifies the corresponding state in the at least one second non-LTM TCI state configuration.

10. The method as described in any one of claims 1 or 2, wherein, Sending the LTM ID, the first LTMDU configuration, and the one or more first LTM TCI state configurations further includes sending the candidate cell ID and physical cell identifier (PCI) of the candidate cell, and wherein sending the first LTM TCI state command further includes sending the candidate cell ID, and the method further includes: Send at least one second LTM TCI state configuration to the UE to configure the corresponding TCI state of the candidate cell; and Send a second LTM TCI state command to activate the at least one second LTM TCI state configuration, wherein the second LTM TCI state command includes the candidate cell ID and at least one second TCI state ID, and the second TCI state ID identifies the at least one second LTM TCI state configuration.

11. A method (1400A to 1400I) for wireless communication performed by a user equipment (UE) (102) configured for low-level triggered mobility LTM, the method comprising: From base station BS (104), via serving cell (124A), receives (1404) an LTM identifier ID, a first LTM Distributed Unit (DU) configuration, and one or more first LTM Transport Configuration Indicators (TCI) state configurations, wherein each of the LTM ID, the first LTM DU configuration, and the one or more LTM TCI state configurations configures a candidate cell (124B); and The first LTM TCI state command is received (1406) via the serving cell to activate a first LTM TCI state configuration in one or more LTM TCI state configurations. The first LTM TCI state command includes the LTM ID and at least one first TCI state ID, and the first TCI state ID identifies a selected first LTM TCI state configuration in one or more first LTM TCI state configurations.

12. The method of claim 11, wherein, The receipt of the LTM ID, the first LTM DU configuration, and the one or more first LTM TCI state configurations, as well as the receipt of the first LTM TCI state command, employ at least one first non-LTM TCI state configuration.

13. The method of any one of claims 11 or 12, wherein, Receiving the LTM ID, the first LTMDU configuration, and the one or more first LTM TCI state configurations includes receiving a second LTM TCI state configuration, and the method further includes: The second LTM TCI state command is received via the candidate cell using the first LTM TCI state configuration to activate the second LTM TCI state configuration.

14. The method of any one of claims 11 or 12, further comprising: Via the candidate cell, using the LTM TCI state configuration, a non-LTM TCI state command is received to activate the second non-LTM TCI state configuration. The non-LTM TCI state command includes the cell index of the candidate cell and at least one second TCI state ID, wherein the second TCI state ID identifies the selected second non-LTM TCI state configuration.

15. The method of any one of claims 11 or 12, wherein, Receiving the LTM ID, the first LTMDU configuration, and the one or more first LTM TCI state configurations further includes receiving the Physical Cell Identifier (PCI) of the candidate cell.

16. The method of claim 15, further comprising: The UE receives the LTM ID and at least one second LTM TCI state configuration, wherein the second LTM TCI state configuration is the candidate cell configured TCI state.

17. The method of claim 15, further comprising: Via the candidate cell, a non-LTM TCI state command is received using the LTM TCI state configuration to activate at least one second non-LTM TCI state configuration. The non-LTM TCI state command includes the cell index of the candidate cell and at least one second TCI state ID, wherein the second TCI state ID identifies the corresponding state in the at least one second non-LTM TCI state configuration.

18. The method of any one of claims 11 or 12, wherein, Receiving the LTM ID, the first LTMDU configuration, and the one or more first LTM TCI state configurations further includes receiving the candidate cell ID and physical cell identifier (PCI) of the candidate cell, and wherein receiving the first LTM TCI state command further includes receiving the candidate cell ID, and the method further includes: Receive at least one second LTM TCI state configuration to configure the corresponding TCI state of the candidate cell; and Receive a second LTM TCI state command to activate the at least one second LTM TCI state configuration, wherein the second LTM TCI state command includes the candidate cell ID and at least one second TCI state ID, and the second TCI state ID identifies the at least one second LTM TCI state configuration.

19. A communication device (102, 204) comprising a transceiver (292, 282), a processor (293, 283), and a computer-readable storage medium (294, 284) storing executable instructions, the executable instructions being used by the processor to perform any of the methods of claims 1 to 18 using the transceiver.

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