Enhancement of TCI state timer operation for LTM

Abstract

A method includes connecting an apparatus to a target cell; starting a timer associated with the one or more transmission configuration indicator states; determining that the one or more transmission configuration indicator states are active prior to connecting to the target cell; and deeming one or more transmission configuration indicator states to be active based on the timer being running, for at least one of lower layer mobility, or for intra-cell / inter-cell beam management within the target cell.

Description

Technical Field

[0001] Example and non-limiting embodiments relate generally to transmission configuration indicator (TCI) states, and more particularly to supervision of active TCI states. Background Art

[0002] RAN1 has agreed to support at least a unified TCI based framework for beam (TCI) indication in Layer 1 / Layer 2 Triggered Mobility (LTM).

[0003] Activating a TCI state before providing a TCI indication, which is selected from one of the activated TCI states, will be beneficial in achieving low handover latency. This is because the UE can start tracking the reference signals (SSB / TRS / CSI-RS) associated with the activated TCI state early to obtain fine quasi-co-location (QCL) parameters (fine time / frequency synchronization) that may be required before starting to use the activated beam as the indicated beam. Summary of the invention

[0004] The following summary is intended to be exemplary only. This summary is not intended to limit the scope of the claims.

[0005] According to one aspect, an example method is provided, comprising: connecting a device to a target cell; starting a timer associated with one or more transmission configuration indicator states; determining that the one or more transmission configuration indicator states are active before connecting to the target cell; and based on the timer being running, treating the one or more transmission configuration indicator states as active for at least one of lower layer mobility or intra-cell / inter-cell beam management within the target cell.

[0006] According to another aspect, an example method is provided, comprising: determining that a device is connected to a target cell; starting a timer associated with one or more transmission configuration indicator states; determining that the one or more transmission configuration indicator states were active prior to connecting to the target cell; and based on the timer being running, treating the one or more transmission configuration indicator states as active for lower layer mobility.

[0007] According to another aspect, an example method is provided, comprising: determining that a device is connected to a target cell; starting a timer associated with one or more transmission configuration indicator states; determining that the one or more transmission configuration indicator states are active before connecting to the target cell; and based on the timer being running, considering the one or more transmission configuration indicator states to be active for intra-cell / inter-cell beam management within the target cell.

[0008] According to another aspect, an example apparatus is provided, comprising: at least one processor; and at least one non-volatile memory storing instructions that, when executed with the at least one processor, cause the apparatus to: connect the apparatus to a target cell; start a timer associated with one or more transmission configuration indicator states; determine that the one or more transmission configuration indicator states are active prior to connecting to the target cell; and based on the timer being running, treat the one or more transmission configuration indicator states as active for at least one of lower layer mobility or intra-cell / inter-cell beam management within the target cell.

[0009] According to another aspect, an example apparatus is provided, comprising: a component for connecting the apparatus to a target cell; a component for starting a timer associated with one or more transmission configuration indicator states; a component for determining that the one or more transmission configuration indicator states are active before connecting to the target cell; and a component for treating the one or more transmission configuration indicator states as active for at least one of lower layer mobility or intra-cell / inter-cell beam management within the target cell based on the timer being running.

[0010] According to another aspect, an example apparatus is provided with a non-volatile program storage device readable by the apparatus, the non-volatile program storage device tangibly embodying an instruction program executable with the apparatus for performing operations comprising: connecting the apparatus to a target cell; starting a timer associated with one or more transmission configuration indicator states; determining that the one or more transmission configuration indicator states are active prior to connecting to the target cell; and based on the timer being running, treating the one or more transmission configuration indicator states as active for at least one of lower layer mobility or intra-cell / inter-cell beam management within the target cell.

[0011] According to another aspect, an example method is provided, including: determining that a user equipment is connected to a target cell; based on determining that the user equipment is connected to the target cell, starting a timer for a serving cell using a network device; and when the timer is running, treating one or more transmission configuration indicator states for the user equipment as active using the network device for the serving cell.

[0012] According to another aspect, an example method is provided, comprising: based on at least one of the following items: sending a cell switching command to a user equipment in a serving cell for switching to a target cell, or receiving a confirmation of the cell switching command from the user equipment for switching the user equipment to the target cell, using a network device to start a timer for the serving cell; and when the timer is running, using the network device for the serving cell, considering one or more transmission configuration indicator states for the user equipment as active.

[0013] According to another aspect, an example method is provided, comprising: based on at least one of the following items: sending a cell switching command to a user equipment in a serving cell for switching to a target cell, or receiving a confirmation of the cell switching command from the user equipment for switching the user equipment to the target cell, using a network device to start a timer for the serving cell; and when the timer is running, using the network device for the serving cell, considering one or more transmission configuration indicator states for the user equipment as active.

[0014] According to another aspect, an example method is provided, comprising: based on at least one of the following items: sending a cell switching command to a user equipment in a serving cell for switching to a target cell, or receiving a confirmation of the cell switching command from the user equipment for switching the user equipment to the target cell, using a network device to start a timer for the serving cell; and when the timer is running, using the network device for the serving cell, considering one or more transmission configuration indicator states for the user equipment as active.

[0015] According to some aspects, the subject matter of the independent claims is provided. Some other aspects are provided in the subject matter of the dependent claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The foregoing aspects and other features are explained in the following description taken in conjunction with the accompanying drawings, in which:

[0017] Figure 1 is a block diagram of one possible and non-limiting example system in which example embodiments may be practiced;

[0018] Figure 2A An example of a Layer 1 / Layer 2 Triggered Mobility (LTM) procedure is shown;

[0019] Figure 2B An example of a Layer 1 / Layer 2 Triggered Mobility (LTM) procedure is shown;

[0020] Figure 3A An example process with activation enhancement is shown;

[0021] Figure 3B An example process with activation enhancement is shown;

[0022] Figure 4A An example method is shown;

[0023] Figure 4B An example method is shown;

[0024] Figure 4C An example method is shown;

[0025] Figure 5 is a diagram illustrating an example method;

[0026] Figure 6 is a diagram illustrating an example method; and

[0027] Figure 7 is a diagram illustrating an example method. DETAILED DESCRIPTION

[0028] The following abbreviations that may be found in the specification and / or drawings are defined as follows:

[0029]

[0030]

[0031]

[0032] Go to Figure 1 , which shows a block diagram of one possible and non-limiting example in which the examples may be practiced. A user equipment (UE) 110, a radio access network (RAN) node 170, and (multiple) network elements 190 are illustrated. For example, examples of network devices, network equipment, or network entities may be understood to include at least a portion of a transmission reception point or cell or gNB or node. In Figure 1In the example of FIG. 1 , a user equipment (UE) 110 wirelessly communicates with a wireless network 100. A UE is a wireless device that can access the wireless network 100. The UE 110 includes one or more processors 120, one or more memories 125, and one or more transceivers 130 interconnected by one or more buses 127. Each transceiver 130 in the one or more transceivers 130 includes a receiver Rx 132 and a transmitter Tx 133. The one or more buses 127 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of wires on a motherboard or integrated circuit, optical fiber, or other optical communication device, etc. The one or more transceivers 130 are connected to one or more antennas 128. The one or more memories 125 include computer program code 123. The UE 110 includes a module 140, including one or both of the parts 140-1 and / or 140-2 that can be implemented in a variety of ways. The module 140 may be implemented in hardware as the module 140-1, such as being implemented as part of the one or more processors 120. Module 140-1 may also be implemented as an integrated circuit or by other hardware (such as a programmable gate array). In another example, module 140 may be implemented as module 140-2, which is implemented as computer program code 123 and executed by one or more processors 120. For example, one or more memories 125 and computer program code 123 may be configured to, together with one or more processors 120, enable user equipment 110 to perform one or more operations described herein. UE 110 communicates with RAN node 170 via wireless link 111.

[0033] In this example, the RAN node 170 is a base station that provides access to the wireless network 100 by a wireless device, such as the UE 110. The RAN node 170 may be, for example, a base station for 5G, also known as New Radio (NR). In 5G, the RAN node 170 may be a NG-RAN node, which is defined as a gNB or ng-eNB. The gNB is a node that provides NR user plane and control plane protocol termination to the UE and is connected to the 5GC (such as, for example, network element (s) 190) via an NG interface. The ng-eNB is a node that provides E-UTRA user plane and control plane protocol termination to the UE and is connected to the 5GC via an NG interface. The NG-RAN node may include multiple gNBs, and it may also include a central unit (CU) (gNB-CU) 196 and (multiple) distributed units (DU) (gNB-DU), of which DU 195 is shown. It should be noted that the DU may include or be coupled to a radio unit (RU) and control the radio unit (RU). The gNB-CU is a logical node that hosts the RRC, SDAP, and PDCP protocols of a gNB or controls the operation of one or more gNB-DUs for the RRC and PDCP protocols of an en-gNB. The gNB-CU terminates the F1 interface connected to the gNB-DU. The F1 interface is illustrated as reference numeral 198, although reference numeral 198 also illustrates a link between a remote element of the RAN node 170 and a centralized element of the RAN node 170, such as between a gNB-CU 196 and a gNB-DU 195. The gNB-DU is a logical node that hosts the RLC, MAC, and PHY layers of a gNB or en-gNB, and its operation is controlled in part by the gNB-CU. One gNB-CU supports one or more cells. One cell is supported by only one gNB-DU. The gNB-DU terminates the F1 interface 198 connected to the gNB-CU. It should be noted that the DU 195 is considered to include the transceiver 160 as part of the RU, for example, but some examples thereof may have the transceiver 160 as part of a separate RU, for example under the control of and connected to the DU 195. The RAN node 170 may also be an eNB (evolved NodeB) base station for LTE (Long Term Evolution), or any other suitable base station or node.

[0034] The RAN node 170 includes one or more processors 152, one or more memories 155, one or more network interfaces ((multiple) N / WI / F) 161, and one or more transceivers 160 interconnected by one or more buses 157. Each of the one or more transceivers 160 includes a receiver Rx 162 and a transmitter Tx 163. The one or more transceivers 160 are connected to one or more antennas 158. The one or more memories 155 include computer program code 153. The CU 196 may include (multiple) processors 152, memories 155, and network interfaces 161. It should be noted that the DU 195 may also contain its own memory / memories and (multiple) processors and / or other hardware, but these are not shown.

[0035] The RAN node 170 includes a module 150, including one or both of the parts 150-1 and / or 150-2, which can be implemented in a variety of ways. The module 150 can be implemented in hardware as the module 150-1, such as being implemented as part of one or more processors 152. The module 150-1 can also be implemented as an integrated circuit or by other hardware (such as a programmable gate array). In another example, the module 150 can be implemented as a module 150-2, which is implemented as a computer program code 153 and is executable by one or more processors 152. For example, one or more memories 155 and the computer program code 153 are configured to, together with the one or more processors 152, enable the RAN node 170 to perform one or more operations as described herein. It should be noted that the functionality of the module 150 can be distributed, such as being distributed between the DU 195 and the CU 196, or implemented only in the DU 195.

[0036] One or more network interfaces 161 communicate over a network, such as via links 176 and 131. Two or more gNBs 170 may communicate using, for example, link 176. Link 176 may be wired or wireless or both, and may implement, for example, an Xn interface for 5G, an X2 interface for LTE, or other suitable interfaces for other standards.

[0037] The one or more buses 157 may be address, data, or control buses, and may include any interconnection mechanism, such as a series of wires on a motherboard or integrated circuit, optical fiber or other optical communication devices, wireless channels, etc. For example, the one or more transceivers 160 may be implemented as a remote radio head (RRH) 195 for LTE or a distributed unit (DU) 195 for a gNB implementation for 5G, while other elements of the RAN node 170 may be physically located at a different location from the RRH / DU, and the one or more buses 157 may be partially implemented as, for example, fiber optic cables or other suitable network connections to connect other elements of the RAN node 170 (e.g., central unit (CU), gNB-CU) to the RRH / DU 195. Reference numeral 198 also indicates those suitable network links (multiple).

[0038] It should be noted that the description herein indicates that a "cell" performs a function, but it should be apparent that the equipment that forms the cell will perform the function. A cell constitutes part of a base station. That is, there may be multiple cells for each base station. For example, there may be three cells for a single carrier frequency and associated bandwidth, each covering one-third of a 360-degree area, so that the coverage area of ​​a single base station covers an approximate ellipse or circle. In addition, each cell may correspond to a single carrier, and a base station may use multiple carriers. So, if there are three 120-degree cells and two carriers for each carrier, the base station has a total of 6 cells.

[0039] The wireless network 100 may include one or more network elements 190, which may include core network functionality and provide connectivity to another network, such as a telephone network and / or a data communication network (e.g., the Internet), via one or more links 181. Such core network functionality for 5G may include access and mobility management function(s) (AMF(s)) and / or user plane functions (UPF(s)) and / or session management functions (SMF(s)). Such core network functionality for LTE may include MME (Mobility Management Entity) / SGW (Serving Gateway) functionality. These are merely exemplary functions that may be supported by the network element(s) 190, and it should be noted that both 5G and LTE functionality may be supported. The RAN node 170 is coupled to the network element 190 via a link 131. The link 131 may be implemented, for example, as an NG interface for 5G, or an S1 interface for LTE, or other suitable interfaces for other standards. The network element 190 includes one or more processors 175, one or more memories 171, and one or more network interfaces ((multiple) N / WI / F) 180 interconnected by one or more buses 185. The one or more memories 171 include computer program code 173. The one or more memories 171 and the computer program code 173 are configured to, together with the one or more processors 175, cause the network element 190 to perform one or more operations.

[0040] The wireless network 100 may implement network virtualization, which is the process of combining hardware and software network resources and network functionality into a single software-based management entity (virtual network). Network virtualization involves platform virtualization, often combined with resource virtualization. Network virtualization is categorized as external, combining many networks or portions of networks into virtual units, or as internal, providing network-like functionality to software containers on a single system. It should be noted that, to some extent, the virtualized entities produced by network virtualization are still implemented using hardware such as processors 152 or 175 and memories 155 and 171, and such virtualized entities also produce technical effects.

[0041] Computer readable memories 125, 155, and 171 may be of any type suitable for the local technical environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. Computer readable memories 125, 155, and 171 may be components for performing storage functions. Processors 120, 152, and 175 may be of any type suitable for the local technical environment and may include, as non-limiting examples, one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. Processors 120, 152, and 175 may be components for performing functions such as controlling UE 110, RAN node 170, and other functions described herein.

[0042] In general, various embodiments of user device 110 may include, but are not limited to, a cellular telephone (such as a smart phone), a tablet computer, a personal digital assistant (PDA) with wireless communication capabilities, a portable computer with wireless communication capabilities, an image capture device with wireless communication capabilities (such as a digital camera), a gaming device with wireless communication capabilities, a music storage and playback device with wireless communication capabilities, an Internet device allowing wireless Internet access and browsing, a tablet computer with wireless communication capabilities, and a portable unit or terminal incorporating a combination of such functionality.

[0043] An example embodiment may provide activation information including a determination of activation and / or deactivation of a TCI state for one or more candidate cells, and more specifically, provide activation information including a determination of activation and / or deactivation of a TCI state for one or more candidate cells, so that the candidate cell may be configured to send at least one of an SSB, a CSI-RS, and a TRS associated with at least one TCI state upon receiving the activation information.

[0044] The features described herein may be used to provide a common understanding of candidate activation TCI states and actual activation TCI states at both the serving cell and the candidate target cells (each of the candidate cells).

[0045] The features described herein may be used to provide a common understanding of candidate activation TCI states and actual activation TCI states at both the serving cell and each candidate target cell.

[0046] According to an example embodiment of the present disclosure, activation information is provided, including determination of activation and / or deactivation of a TCI state for one or more candidate cells, so that the candidate cell can be configured to send at least one SSB, CSI-RS, and TRS associated with the TCI state upon receiving the activation information.

[0047] Release 18 Lower Layer Mobility

[0048] In 3GPP, lower layer mobility was discussed in Release 18 as part of a work item called Further NR Mobility Enhancements [RP-222332]. It was agreed to use the term Layer 1 / Layer 2 Triggered Mobility (LTM) for lower layer mobility. In the work item description [RP-222332], Goal #1 to address LTM is described as follows:

[0049] ●Specify L1 / L2 based inter-cell mobility mechanisms and procedures to reduce mobility delay:

[0050] ○ For configuration and maintenance of multiple candidate cells to allow rapid application of configuration for candidate cells [RAN2, RAN3]

[0051] ○ Dynamic switching mechanism between candidate serving cells (including SpCell and SCell) for potential applicable scenarios based on L1 / L2 signaling [RAN2, RAN1]

[0052] ○ L1 enhancements for inter-cell beam management, including L1 measurements and reporting, and beam indication [RAN1, RAN2]

[0053] - Note 1: Early RAN engagement is necessary, including further clarification of the potential for interaction between this bullet and previous bullets

[0054] ○Timing Advance (TA) Management [RAN1, RAN2]

[0055] ○ CU-DU interface signaling supports L1 / L2 mobility if required [RAN3]

[0056] Note 2: FR2-specific enhancements are not excluded (if any).

[0057] Note 3: The L1 / L2-based inter-cell mobility process is applicable to the following scenarios:

[0058] ■ Standalone, CA and NR-DC scenarios with changes in serving cells within a CG

[0059] ■ Intra-DU and intra-CU inter-DU scenarios (applicable to standalone and CA: no new RAN interface)

[0060] ■Both intra-frequency and inter-frequency

[0061] ■Both FR1 and FR2

[0062] ■The source and target cells can be synchronized or not

[0063] Following the latest conventions, the LTM process can be captured in the following MSC [R2-2213292], extended for decomposition architecture. Figure 2A and Figure 2B :

[0064] ● Steps 1 to 3: UE sends L3 Measurement Report message to CU via source DU. CU decides to use LTM and initiates LTM candidate cell preparation.

[0065] ● Steps 4 to 5: CU sends UE context setup request to target DU to prepare target cell

[0066] ● Steps 6 to 7: The CU sends a UE context modification request to the source DU for preparing the target cell in the source DU. Additionally, this message can be used to provide the source DU with target cell information.

[0067] • Steps 8 to 12: CU prepares the RRC configuration and provides it to the UE. The UE stores the configuration of the LTM candidate target cell(s) and sends an RRCReconfigurationComplete message to the CU.

[0068] • Step 13: The UE may perform DL synchronization.

[0069] • Steps 14 to 16: The source DU instructs the UE to perform TA acquisition on the target DU using RACH. The target DU then provides the TA to the UE (there are several options still open - directly or via the source DU).

[0070] • Step 17: The UE performs L1 measurements on the configured LTM candidate target cell(s) and sends a lower layer measurement report to the source DU.

[0071] • Steps 18 to 19: The source DU decides to perform an LTM cell handover to the target cell and sends a MAC CE triggering the LTM cell handover.

[0072] • Step 20: The UE switches to the configuration of the LTM candidate target cell and accesses the target cell. If necessary (if timing advance is not available), it will perform a random access.

[0073] • Steps 21 to 22: The UE uses RRC Reconfiguration Complete to indicate that the handover from the LTM cell to the target cell is successfully completed.

[0074] • Steps 23 to 24: If the CU decides accordingly, the UE context is released.

[0075] The MAC-CE command in step 19 is also known as a cell handover command. It has been agreed in RAN1 that the command will contain at least the beam indication of the target cell, which the UE can use to communicate with the target cell after the cell handover. Furthermore, it has been agreed to use a unified TCI framework based on Release 17 to provide the beam indication of the target cell. The beam indication can simply refer to the TCI state of the associated cell.

[0076] The following agreement is a subset of what was agreed on beam pointing at the Rel-18 RAN1 meeting on LTM:

[0077] ● If both the serving cell and the candidate cell support the Rel-17 unified TCI framework, the beam indication of Rel-18 LTM is designed based on the Rel-17 unified TCI framework.

[0078] ●For beam indication timing for Rel-18 LTM, support for scenario 2: beam indication with cell handover command,

[0079] ● Beam indication for target cell(s) is communicated in MAC CE for LTM triggering in scenario 2

[0080] ● At least for the beam indication based on the Rel-17 unified TCI framework included in the cell handover command (i.e., scenario 2), the beam indication is applicable to the signals / channels that follow or are configured to follow the Rel-17 unified TCI at the target cell(s)

[0081] ●For the beam indication based on the Rel-17 unified TCI in the Rel-18 LTM, before receiving the beam indication of the candidate cell, at least the TCI state activation of the candidate cell is received.

[0082] • The UE may indicate and activate a single joint TCI state or a pair of UL / DL TCI states in the cell handover command.

[0083] ●Each TCI state includes at most 2 qcl types, and each qcl type source RS in the QCL information of the TCI state is provided based on at least the RS configuration for LTM.

[0084] ● For TCI state activation for candidate cell(s) before cell handover command, MAC CE is used and the details of MAC-CE for TCI state activation for LTM depend on RAN2

[0085] LTM and CU / DU network architecture in 3GPP

[0086] In 3GPP, LTM refers to Layer 1 (L1) / Layer 2 (L2) triggered mobility (also known as L1 / L2 inter-cell mobility). LTM stands for mobility enhancement, which, among other things, provides decisions about cell changes based on at least L1 measurements (e.g., physical layer measurements), and according to 3GGP, the decision is made in the medium access control (MAC) (e.g., layer 2) part of the gNB-DU. In 5G (e.g., also known as New Radio (NR)), a base station (e.g., next generation Node B, gNB) can be a separate or distributed base station including a gNB central unit (CU) and one or more gNB distributed units (DUs), which can serve one or more cells. For example, a DU can include one or more transmission reception points (TRPs) to serve one or more corresponding cells. The gNB CU can include non-time-critical functionality (which can be hosted locally or on the cloud). The gNB-DU includes real-time functionality such as radio link control (RLC), medium access control (MAC), and physical (PHY) layer functions. The F1 interface provides control (F1-C) and user (F1-U) plane connectivity between the CU and DU. The F1 interface also provides separation between the radio network and transport network layers while enabling the exchange of UE and non-UE associated information.

[0087] R17, unified TCI status framework

[0088] A framework based on Rel-17 unified TCI for beam (TCI) indication in LTM is supported. In the unified TCI state framework (or unified TCI), a list of RRC-configured TCI states (e.g., 64 TCI states) may be provided to the UE, which may be activated using a MAC CE (e.g., up to 8 TCI states) and further indicated using DCI (one TCI state). If a single TCI is activated by the MAC-CE, one activation is considered as the indicated TCI state. TCI states may be indicated separately for UL and DL (separate TCI states) or for joint TCI, i.e., the same TCI applies to both UL and DL.

[0089] The DCI indication (providing the beam indication) includes a code point value that maps / refers to the TCI state ID activated by the MAC CE (because the MAC-CE can activate up to 8 TCI states).

[0090] Delay requirements using the activated TCI state

[0091] For unified TCI state activation of one or more joint or separate DL / UL unified TCI states, RAN4 defines the latency requirements for activation of DL TCI states in Section 8.15 of TS38.133, and the latency requirements for activation of UL TCI states in Section 8.16. Requirements for TCI state activation are defined separately (adding TCI states on the active TCI state list) when one (Sections 8.15.3 and 8.16.3) or multiple (Sections 8.15.5 and 8.16.5) TCI states are activated.

[0092] The TCI state switching delay for adding a TCI state to the active TCI state list is defined separately for known and unknown TCI states. For example, for the known TCI state case, the delay requirement for the DL TCI state is as follows:

[0093] If the target TCI state is known, upon receiving the PDSCH carrying the MAC-CE activation command in time slot n, the UE shall be able to The UE shall be able to receive the UE-specific PDCCH / PDSCH with the target TCI state of the serving cell where the TCI state switch occurs at the first time slot after the time slot length. The UE shall be able to receive the UE-specific PDCCH / PDSCH with the old TCI state until the time slot Where T HARQ (in time slots) is the timing between DL data transmission and acknowledgment as specified in TS 38.213 [3];

[0094] ○ T first-SSB is the time of the first SSB transmission after the UE decodes the MAC CE command; the SSB should be QCL-Type A or QCL-Type C of the target TCI state

[0095] ○ T SSB-proc =2ms;

[0096] ○ If the target TCI state is not in the active TCI state list for PDSCH / PDCCH, then TO k =1, otherwise 0.

[0097] RAN1 has reached an agenda to at least support a unified TCI-based framework for beam (TCI) indication in LTM. As mentioned in U.S. Provisional Patent Application No. 63 / 459,035 filed on April 13, 2023, which is incorporated herein by reference in its entirety, activating a TCI state before providing a TCI indication (the TCI indication is selected from one of the activated TCI states) will be beneficial in achieving low handover latency because the UE can start tracking the reference signals (SSB / TRS / CSI-RS) associated with the activated TCI state as early as possible to obtain fine quasi-co-location (QCL) parameters (fine time / frequency synchronization) that may be required before starting to use the activated beam as an indication beam. As described in U.S. Provisional Patent Application No. 63 / 459,035, a timer is configured for the UE, wherein the timer is used to monitor the validity of the activated TCI state. When the UE determines that it has received a TCI state activation for LTM purposes (i.e., not an intra-cell BM), the validity timer is started. While the timer is running, the UE considers the TCI state to be active and may expect a beam indication of one of the TCI states in the active TCI state (of the target candidate cell) in preparation for cell switching and / or. When the timer expires, the UE assumes that the TCI state associated with the expired timer is deactivated. The above may depend on whether the UE is configured with a timer. Otherwise, the activated TCI state does not expire.

[0098] If TCI activation is not completed before cell handover or cell change, the UE needs to meet certain minimum delay requirements (in order to obtain fine time / frequency synchronization) before it can start using the indicated beam.

[0099] Therefore, in a typical scenario, the UE will be provided with an activation command for a set (one or more) of TCI states that may be indicated by the network; furthermore, in an LTM scenario, the UE may have one or more candidate cells.

[0100] Beam indication can be used to indicate the active TCI state. Currently, if an activation command (and later indication) for (multiple) TCI states is provided to the UE, and only when a cell handover or cell change is also indicated to the target cell, there may be a timeline mismatch between the target cell and the UE, and for example the UE is ready to receive / transmit, but the target DU may still process the beam indication internally (i.e., arrange transmission schedule and capacity, etc.). In other words, the target DU needs to be prepared to accommodate (e.g. in terms of reference signal transmission, scheduling, etc.) new UEs entering the cell in any TCI state configured by the RRC.

[0101] Therefore, there needs to be a mechanism to provide a common understanding of the candidate activation TCI states and the actual activation TCI states at both the serving cell and the candidate target cells (each of the candidate cells).

[0102] As similarly explained above, there needs to be a mechanism to provide a common understanding of the candidate activation TCI states and the actual activation TCI states at both the serving cell and the candidate target cells (each of the candidate cells).

[0103] In an exemplary embodiment of the present disclosure, when a source cell determines to activate one or more TCI states for one or more candidate cells, information of the activated TCI state in a message (eg, an activation message) is provided to the associated one or more cells.

[0104] Wherein, upon receiving a list of one or more activated TCI states by the candidate cell, it may be assumed that the TCI state is active and one (or more) active TCI states may be indicated to the UE. The candidate cell may be configured to send at least one of SSB, CSI-RS, and TRS (associated with the activated (multiple) TCI states) when activation information containing information of the activated (multiple) TCI states has been received.

[0105] The association of a reference signal (e.g., at least one of SSB, CSI-RS, and TRS) with a TCI state may imply / mean that the TCI state includes associated (multiple) reference signals. Alternatively or additionally, the reference signal included in the TCI state is used as a quasi-co-site (QCL) source reference signal for (multiple) another (target) reference signal. As an example, if the TCI state is activated and the reference signal associated with the TCI state (used as a source) is sent, the target signal may be sent. As an example, if the TCI state is activated and the reference signal is associated with the TCI state, the target signal may be sent.

[0106] The quasi co-location assumption between the source and target signals (i.e., there is a QCL source and a QCL target) means that from the (UE) reception perspective, they may share the same characteristics, such as in terms of Doppler shift, Doppler spread, average delay, delay spread, spatial RX (the UE can use the same RX beam for both signals).

[0107] In an example embodiment, when the source cell determines to deactivate one or more TCI states for one or more candidate cells, information of the deactivated TCI states in a message (eg, a deactivation message) is provided to the associated one or more cells.

[0108] Wherein, after receiving the list of deactivated TCI states by the candidate cell, it can be assumed that the TCI state indicated as deactivated is no longer active. When the TCI state is not activated, the candidate cell can determine not to send at least one of SSB, CSI-RS and TRS (associated with (multiple) TCI states). Any TCI state not indicated as deactivated is still active.

[0109] In one example embodiment, the target cell may provide a list of "candidate TCI states" that may be considered for activation. In one option, the source cell may need to select one or more of the TCI states for activation from the list provided by the target cell.

[0110] In an example embodiment, a timer-based management method for activating a TCI state may be configured for candidate cell(s):

[0111] - a timer is configured to be maintained at the candidate cell;

[0112] - A timer is started: When a candidate cell receives an activation indication for one or more TCI states:

[0113] ○ The same timer may be configured and started at the source cell;

[0114] - While the timer is running, the candidate cell may assume that the TCI state is active, and one (or more) active TCI states may be indicated for the UE. While the timer is running, the candidate cell may be configured to transmit at least one of SSB, CSI-RS and TRS (associated with (multiple) TCI states):

[0115] o In yet another example, when the timer runs, the candidate cell is expected to be ready to provide communications on the TCI state resources (e.g., if the beam indication provided to the UE is one of the TCI states of the candidate cell);

[0116] - When the timer expires: the candidate cell may automatically deactivate the TCI state received from the source cell after a duration T;

[0117] ○ In yet another example, the duration T is communicated to the source DU and the UE. In addition, when sending an activation indication to the candidate cell, the source cell may also indicate the UE;

[0118] - The timer may be specific to a candidate cell or a set of candidate cells;

[0119] - The timer value may be determined by the candidate cell (or the CU of the candidate cell), and the timer value may be indicated to the source cell (and / or other cells) as part of the LTM configuration.

[0120] In a further UE related example embodiment, a timer is configured for the UE, wherein the timer is used to supervise the validity of the activated TCI state:

[0121] - When the UE determines that it has received a TCI state activated for LTM purposes (i.e. not an intra-cell BM), the validity timer is started;

[0122] - While the timer is running, the UE considers the TCI state to be active and may expect to prepare for cell handover, cell change, and / or a beam indication of one of the TCI states in the active TCI state (of the target candidate cell);

[0123] - When the timer expires, the UE assumes that the TCI state associated with the expired timer is deactivated;

[0124] The above may depend on whether the UE is configured with a timer. Otherwise, the activated TCI state will not expire.

[0125] In an exemplary embodiment of the present disclosure, when sending a cell switching or cell change command (and associated beam indication) to a UE, the source DU may provide an indication to other candidate target DUs to release activation (i.e., determine that the TCI state is no longer activated for beam indication), so that the receiver target DU may apply energy saving after receiving the activation, i.e., determine that one or more reference signals associated with (multiple) TCI states activated for LTM are not sent at least for the UE at the source cell.

[0126] In a further example embodiment, the indication to release at least one activation to the candidate target cell / DU may include one or more TCI states (eg, selected from the activated TCI states of the candidate cell). The candidate target cell / DU may deactivate the indicated TCI state.

[0127] In one example option, the candidate target DU to which the indication is sent may be a target DU selected for a cell handover or cell change of the UE.

[0128] In another example, the candidate target DU to which the indication is sent may be a target DU that is not selected for cell handover or cell change of the UE.

[0129] In this document, the terms cell handover and cell change are used interchangeably.

[0130] In an example embodiment, after transmitting a cell switching command (and associated beam indication) to the UE, the source DU may provide an indication to other candidate target DUs not to release activation (i.e., determining that the TCI state is still activated for beam indication).

[0131] In an example option, this may restart the timer used to manage the active state of the TCI state.

[0132] In a further example embodiment, the indication not to release activation to the candidate target cell / DU may include one or more TCI states (eg, selected from the activated TCI states of the candidate cell). The candidate target cell / DU may maintain the indicated TCI state activated.

[0133] In one example option, the candidate target DU to which the indication is sent may be a target DU selected for cell handover of the UE.

[0134] In another example, the candidate target DU to which the indication is sent may be a target DU that is not selected for cell switching of the UE.

[0135] In an example embodiment, the beam indication (or information of the beam indication, such as TCI status) of a specific target cell may be delivered to one or more candidate target cells (other candidate target cells not selected for cell handover):

[0136] ○ Option 1, which may cause the receiver candidate target cell to consider one or more activated TCI states deactivated for the UE;

[0137] ○ Option 2, which may cause the receiver candidate target cell to restart the timer to maintain the active TCI state as still active. Motivation: The UE may be handed over to another cell soon, as the UE is most likely located at the cell border. This will also have an impact on the UE, as the UE should prepare another beam indication (i.e., it should not assume that the TCI state of other cells is deactivated).

[0138] In one example option, the UE may be indicated (eg, in a cell handover command) candidate target cells that may maintain the TCI state as active after the cell handover command.

[0139] In one example option, the beam indication information may include information of the selected target cell (eg, the identity of the target cell).

[0140] Examples of potential signaling may include a basic procedure that only shows the activation portion when the information of the active TCI state is coordinated with the associated candidate cells at TCI activation before cell switching. These enhancements for activation are Figure 3A and Figure 3B Shown in.

[0141] Figure 3A and Figure 3B The process with enhancements for activation is shown. It can be seen Figure 3A and Figure 3BThe novel operation in Figure 3A As shown in step 14, DU 1 determines the TCI state of DU 2 to be activated for LTM. Figure 3A and Figure 3B As shown in step 16 of , during the activation of option 1 at 15, Figure 3A and 3B There is TCI activation between DU 1 and UE. Figure 3A and Figure 3B As shown in step 17 of , there is another operation according to an exemplary embodiment of the present disclosure, in which DU 1 sends information of the activation status of DU 2 to CU and DU 2 (target cell). Figure 3A and Figure 3B As shown in step 19 of , during activation of option 2 at 18, there is a selected TCI state of DU2 to be activated. Figure 3A and Figure 3B As shown in step 20 of FIG. 18 , during option 2 in advance, an ACK or an alternative list for the activated TCI state is sent from DU 2 to DU 1. Figure 3A and Figure 3B After step 24 in which DU 1 decides on cell switching and selects the TCI state to be indicated, there is Figure 3B Another step 30, wherein DU 2 sends an ACK or an alternative TCI indication to CU and DU 1. Figure 3A and Figure 3B As shown in step 25 of , there is 25 indicating option 1. Figure 3A and Figure 3B During the indication option 1 shown in step 26 of , there is a cell switching command (TCI indication) from DU1 to UE. Figure 3A and Figure 3B As shown in step 27 of , DU 1 sends the indicated TCI status of DU 2 to CU and DU 2 (target cell). Figure 3A and Figure 3B As shown in step 28 of , there is 28 indicating option 2. Figure 3A and Figure 3B During this indication option 2 shown in step 29 of , the indicated TCI status of DU 2 is sent from DU 1 to CU and DU 2 (target cell). Then, as Figure 3A and Figure 3B As shown in step 30 of FIG. 1 , ACK or an alternative TCI indication is sent from DU 2 to CU and DU 1. Figure 3A and Figure 3B As shown in step 31 in FIG. 1 , a cell switching command (TCI indication) is sent from DU 1 to UE. Then, as shown in FIG. Figure 3A and Figure 3BAs shown in step 32 of , there is a cell change. At least some of these steps are added to improve the operation, for example, for TCI state activation or deactivation during a cell change.

[0142] Figure 4A , Figure 4B and Figure 4C Example methods are shown respectively.

[0143] Figure 4A The diagram illustrates operations that can be performed by a network node. Figure 4A As shown in step 410 of , for communication with a user equipment during or after a cell change, there is a determination to activate or deactivate one or more transmission configuration indicator states for at least one candidate cell. Figure 4A As shown in step 420 of , there is information being communicated to at least one candidate cell indicating one or more transmission configuration indicator states of activation or deactivation.

[0144] According to an example embodiment, the apparatus may be implemented in a network node of a source cell of a communication network.

[0145] According to an example embodiment, the information may include activation information.

[0146] According to an example embodiment, the information may be configured to cause at least one candidate cell to transmit at least one of a synchronization signal block, a channel state information reference signal, a tracking reference signal, or other signals.

[0147] According to an example embodiment, the information may be configured to cause at least one candidate cell to transmit at least one of a synchronization signal block, a channel state information reference signal, a tracking reference signal, or other signals associated with at least one transmission configuration indicator state.

[0148] According to an example embodiment, the information may be configured to cause at least one candidate cell to transmit a synchronization signal block, a channel state information reference signal, a tracking reference signal, or at least one other signal associated with activation information (including one or more TCI states).

[0149] According to an example embodiment, an activation message for one or more transmission configuration indicator states may be provided to at least one candidate cell.

[0150] According to an example embodiment, the configuration of the timer may be sent to at least one candidate cell.

[0151] According to an example embodiment, a timer may be configured when an activation message is provided to a candidate cell.

[0152] According to an example embodiment, when the activation message is provided, the timer may be configured to start.

[0153] According to an example embodiment, when the timer is running, the timer may be configured to cause the candidate cell to identify the activated or deactivated one or more transmission configuration indicator states as active, and wherein the activated or deactivated one or more transmission configuration indicator states are activated for the user equipment.

[0154] According to an example embodiment, while the timer is running, the timer may be configured to cause at least one candidate cell to transmit at least one of a synchronization signal block, a channel state information reference signal, a tracking reference signal, or other signals.

[0155] According to an example embodiment, while the timer is running, the timer may be configured to cause at least one candidate cell to provide communications to the user equipment on one or more resources associated with one or more transmission configuration indicator states that are activated or deactivated.

[0156] According to an example embodiment, at least one candidate cell may be configured to provide communications to the user equipment based on a beam indication provided to the user equipment, the beam indication being one of the one or more transmission configuration indicator states that is activated or deactivated.

[0157] According to an example embodiment, the timer may be configured such that at least one candidate cell deactivates the activated one or more transmission configuration indicator states communicated by the source cell after a duration T based on expiration of the timer.

[0158] According to an example embodiment, the communication may configure at least one candidate cell with a duration T.

[0159] According to an example embodiment, the configuration of the timer of at least one candidate cell may be communicated as part of the lower layer mobility configuration.

[0160] According to an example embodiment, the configuration of the timer communicated as part of the lower layer mobility configuration may include at least one of a layer 1 or layer 2 triggered mobility configuration.

[0161] According to an example embodiment, the configuration of the timer may be specific to a candidate cell or a set of candidate cells in the at least one candidate cell.

[0162] According to an example embodiment, there may be a cell change command based indication to send a release of at least one activation for beam indication to at least one candidate cell, wherein the release enables at least one candidate cell to determine not to send one or more reference signals associated with one or more transmission configuration indicator states that are activated or deactivated for lower layer mobility of the user equipment.

[0163] According to an example embodiment, the release at least one activated indication sent to the candidate target cell may include one or more activated transmission configuration indicator states selected from the activated transmission configuration indicator states of the candidate cell.

[0164] According to an example embodiment, there may be a cell handover command sent to the user equipment to send an indication to at least one candidate cell not to release at least one activation for beam indication.

[0165] According to an example embodiment, the indication of release may cause a timer to be restarted for managing and maintaining an activity state of one or more activated transmission configuration indicator states.

[0166] According to an example embodiment, the indication of the release may include one or more activated transmission configuration indicator states selected from the activated transmission configuration indicator states of the candidate cells.

[0167] According to an example embodiment, there may be at least one candidate cell information transmitting the transmission configuration indicator state regarding the beam indication or activation to a specific target cell.

[0168] Figure 4B The diagram illustrates operations that can be performed by a network node. Figure 4B As shown in step 440 of , during or after a cell change using a user equipment, information of one or more transmission configuration indicator states that are activated or deactivated is received. Figure 4B As shown in step 450 of , there is information being sent to the user equipment including an indication of one or more transmission configuration indicator states being activated or deactivated.

[0169] According to an example embodiment, the apparatus may comprise a network node of a candidate cell of a communication network.

[0170] According to an example embodiment, the information may include activation information.

[0171] According to an example embodiment, based on the information, the network node may be configured to send at least one of a synchronization signal block, a channel state information reference signal, a tracking reference signal, or other signals.

[0172] According to an example embodiment, there may be receiving information including a configuration of a timer from a source network.

[0173] According to an example embodiment, there may be a timer started during communication with the source network based on this information.

[0174] According to an example embodiment, the network node may be configured to maintain a timer.

[0175] According to an example embodiment, the network node may be configured to start a timer during communication with the source network.

[0176] According to an example embodiment, while the timer is running, the network node may be configured to identify the activated or deactivated one or more transmission configuration indicator states as active, and wherein the activated or deactivated one or more transmission configuration indicator states are activated for the user equipment.

[0177] According to an example embodiment, when the timer is running, the network node may be configured to send at least one of a synchronization signal block, a channel state information reference signal, a tracking reference signal, or other signals.

[0178] According to an example embodiment, while the timer is running, the network node may be configured to provide communications to the user equipment on one or more resources associated with one or more transmission configuration indicator states that are activated or deactivated.

[0179] According to an example embodiment, the network node may be configured to provide communications to the user equipment based on a beam indication provided to the user equipment, the beam indication indicating one of the one or more transmission configuration indicator states being activated or deactivated.

[0180] According to an example embodiment, the network node may be configured to deactivate the activated one or more transmission configuration indicator states communicated by the source cell after a duration T based on expiry of a timer.

[0181] According to an example embodiment, the network node may be configured with a duration T in the communication.

[0182] According to an example embodiment, the configuration of the timer may be communicated as part of the lower layer mobility configuration.

[0183] According to an example embodiment, the configuration of the timer communicated as part of the lower layer mobility configuration may include at least one of a layer 1 or layer 2 triggered mobility configuration.

[0184] According to an example embodiment, the configuration of the timer may be specific to a candidate cell or a set of candidate cells in the at least one candidate cell.

[0185] According to an example embodiment, there may be an indication received from a source network to release at least one activation for beam indication, wherein the release enables at least one candidate cell to determine not to transmit one or more reference signals associated with one or more transmission configuration indicator states that are activated or deactivated for activation of a lower layer mobility configuration of a user equipment.

[0186] According to an example embodiment, the release at least one activated indication sent to the candidate target cell may include one or more activated transmission configuration indicator states selected from the activated transmission configuration indicator states of the candidate cell.

[0187] According to an example embodiment, there may be a determination not to release at least one activated indication for beam indication based on a cell handover command sent to the user equipment.

[0188] According to an example embodiment, the indication of release may cause a timer to be restarted for managing and maintaining an activity state of one or more activated transmission configuration indicator states.

[0189] According to an example embodiment, the indication of the release may include one or more activated transmission configuration indicator states selected from the activated transmission configuration indicator states of the candidate cells.

[0190] According to an example embodiment, there may be information determining a transmission configuration indicator state regarding beam indication or activation to a specific target cell.

[0191] According to an example embodiment, an apparatus may be provided, comprising: a component for receiving a message of one of one or more transmission configuration indicator states being activated or deactivated by a network node of a communication network having a source network during or after a cell change utilizing a user equipment; and a component for sending information including an indication of one of the one or more transmission configuration indicator states being activated or deactivated to the user equipment.

[0192] Figure 4C The diagram illustrates operations that can be performed by a network device. Figure 4C As shown in step 470 of , there is receiving information including an indication of one or more transmission configuration indicator states being activated or deactivated. Figure 4C As shown in step 480 of , based on the information, a timer configuration for verifying the activated or deactivated state of one or more transmission configuration indicators is determined.

[0193] According to an example embodiment, the apparatus may be implemented in a user equipment of a communication network.

[0194] According to an example embodiment, a timer configuration may be used to verify one of the one or more transmission configuration indicator states being activated or deactivated.

[0195] According to an example embodiment, the timer configuration may configure a timer that is started when an indication of one or more transmission configuration indicator states that are activated or deactivated is used for lower layer purposes.

[0196] According to an example embodiment, the timer configuration communicated as part of the lower layers may include at least one of a layer 1 or layer 2 triggered mobility configuration.

[0197] According to an example embodiment, when the timer is running, the user equipment may identify one or more activated or deactivated transmission configuration indicator states as active, and prepare to switch the cell switching or beam indication to one of the one or more activated transmission configuration indicator states.

[0198] According to an example embodiment, while the timer is running, based on the information, the user equipment may be configured to provide communications on one or more resources associated with one or more transmission configuration indicator states that are activated or deactivated.

[0199] According to an example embodiment, based on the information, the user equipment may be configured to receive or send communications based on a beam indication, which is one of the one or more transmission configuration indicator states that is activated or deactivated.

[0200] According to an example embodiment, based on the information, the user equipment may be configured to monitor at least one of a synchronization signal block, a channel state information reference signal, or a tracking reference signal associated with one or more transport configuration transmission configuration indicator states of activation or deactivation.

[0201] According to an example embodiment, based on the expiry of the timer, the user equipment may assume that the transmission configuration indicator associated with the timer is to be deactivated.

[0202] benefit:

[0203] Knowledge of the TCI states activated at the respective candidate target cells may be beneficial, for example, in terms of scheduling of the associated DL RS. For example, if there is no activated TCI state associated with the RS, the candidate target cell may turn off RS transmission (e.g., if there is no UE that needs to be served by the beam associated with the TCI state, the candidate cell may apply a power saving mechanism to avoid transmitting CSI-RS / CSI-RS for TRS).

[0204] Implicit management of the activated TCI state is handled via timers: based on timers maintained at the candidate cells.

[0205] The benefit and / or motivation is that the beam indication for LTM cell switching may never be provided to that specific candidate cell, so that cell will remain activated for the TCI state for a long time (i.e., it needs to be assumed that the UE can be switched to that target cell and is even ready to provide UL grant / send TRS / CSI-RS).

[0206] Additionally, it provides a candidate cell way to maintain a preparation of a set of TCI states (rather than all potential TCI states) that may be "potential candidates" before the serving cell is actually activated.

[0207] It provides a mechanism for candidate cells to restrict the TCI states that can be activated for a UE. This provides a way to perform load balancing / load management (e.g. in the spatial domain) for candidate DU resources.

[0208] Similarly, it would be beneficial for candidate cells to be aware of any deactivation of an activated TCI state.

[0209] In addition, according to the example embodiments of the present disclosure, there is a circuit system for performing the operations according to the example embodiments of the present disclosure disclosed herein. The circuit system may include any type of circuit system, including content encoding circuit system, content decoding circuit system, processing circuit system, image generation circuit system, data analysis circuit system, etc.). In addition, the circuit system may include a discrete circuit system, an application-specific integrated circuit system (ASIC), and / or a field programmable gate array circuit system (FPGA), etc., and a processor specially configured by software to perform corresponding functions, or a dual-core processor with software and a corresponding digital signal processor, etc. In addition, necessary inputs to the circuit system and necessary outputs from the circuit system, functions performed by the circuit system, and interconnections (possibly via inputs and outputs) of the circuit system with other components that may include other circuit systems are provided to perform the example embodiments of the present disclosure described herein.

[0210] According to an example embodiment, a timer for supervising active TCI states may be started when the UE successfully connects to a new target cell. Thus, it may not be necessary to start a timer when an activation command is received; before the UE connects to a new target cell. In another example, a timer may be started when an activation command is received to activate one or more TCI states, and the timer may also be restarted when the UE connects to a new target cell (as a result of an LTM cell switch or an LTM-based handover). TCI state activation may not require the timer to be started prior to a cell switch, such as where the HO completion of an LTM target initiates a timer. This is different from TCI state activation, which would start a timer prior to a cell switch; where the HO completion of an LTM target initiates a timer.

[0211] In a typical scenario, the UE may be provided with an activation command for a set (one or more) of TCI states that may be indicated by the network. In addition, in an LTM scenario, the UE may have one or more candidate cells. In the LTM context, an indication of at least one TCI state may indicate that the UE is connected to the target cell using the indicated TCI state. The TCI state provides the UE with information about the reference signal (e.g., DL RS) used as a reference for downlink reception of uplink transmissions.

[0212] One motivation for LTM (e.g. compared to conventional L3 mobility) is support for (subsequent) LTM-based handovers and / or handovers that can be performed using lower layer signaling, where the lower layer signaling indicates to the UE the type of beam switching operation for HO, rather than performing a RACH-based HO (which may otherwise result in interruption of data / connectivity between the UE and the network or lower throughput). LTM-based handovers can also use RACH-based handovers, but (multiple) TCI states can be activated and / or indicated before the cell switch, or indicated in the LTM cell switch command. Although RACH-based LTM handovers may result in interruptions, if the previously activated TCI state is maintained, the UE can switch to another target cell or another TCI state in the target cell (for beam management) with less delay. As an example, beam indication can be used to switch a UE between a set of cells (including switching back to a previous serving cell if the serving cell is configured as an LTM candidate cell). Using beam indication for handover, it can be assumed that the interruption to data communication is minimal. The beam indication can indicate at least one previously activated TCI state. In some cases, the beam indication may indicate at least one TCI state (not previously activated) such that the indicated TCI state is activated (and indicated). In some examples, activating one TCI state may cause the activated TCI state to be indicated.

[0213] Since lower layer signaling indicates to the UE the current QCL assumption to be used in the target cell using beam indication (or indication of TCI state or indication of activated TCI state), the TCI state that may be indicated in the cell switching command must be managed efficiently. A QCL assumption may refer to a UE assumption or reference for receiving a downlink channel (PDCCH and / or PDSCH) or for transmission on an uplink channel (PUCCH and / or PUSCH).

[0214] A TCI state that can be indicated is generally referred to as an active TCI state. In some examples, an inactive TCI state can be indicated (and the indication further leads to activation of the TCI state).

[0215] The active TCI state means that the UE is assumed to perform beam switching to the active TCI at a specified time (sometimes referred to as the beam application time, i.e., the time when the beam or new TCI state is applied / used).

[0216] • If the TCI state is deactivated immediately after handover, efficient (subsequent) LTM cell handover will be prevented.

[0217] ● Alternatively, if the new target cell always needs to deactivate the TCI state for a specific cell or cells, it will increase signaling overhead and improve resource utilization.

[0218] • It may also reduce the flexibility of network scheduling due to the need for additional signaling; ie, signaling deactivation.

[0219] In the (subsequent) LTM case, it is beneficial to keep some or all TCI states active after an LTM cell switch, but if a (subsequent) LTE cell switch does not occur within a reasonable time frame after the first LTM cell switch, it is not defined how long the TCI state should remain active after the first cell switch. TCI being active means that the UE is performing (fine) time / frequency tracking of the TCI state (of the DL RS included in the TCI state), which may unnecessarily consume UE resources if the TCI state remains active for a long time when not needed. In some examples, an LTM handover may be referred to as a subsequent LTM cell handover, where after performing an LTM cell handover to a target cell, the UE is switched to another target cell (the UE has an LTM candidate cell configuration). In some examples, a subsequent LTM handover may refer to a cell handover (back) to a previous serving cell.

[0220] In an example embodiment, a timer T may be configured to monitor the active TCI state (for LTM) after the UE enters (successfully connects) to a new target LTM cell. Timer T may be associated with one or more TCI states. The timer may be started when the UE successfully connects to the target cell using the TCI indicated in the cell switching command. For example, the timer may be started when the UE sends an RRC reconfiguration complete or the UE receives an acknowledgment of a UL-SCH transmission carrying the RRC reconfiguration complete. The timer may be restarted when the UE successfully connects to the target cell using the TCI indicated in the cell switching command and the timer is running, for example when the timer has been started after a TCI state activation command is received before the cell switching.

[0221] While the timer is running, the UE may consider that the TCI states associated with the timer T are active (after cell switching), which TCI states were activated before the cell switching.

[0222] When the timer T expires, the UE may assume that the TCI state associated with the timer is no longer active.

[0223] In one example, referring to Figure 3A and Figure 3B The described timer can be restarted upon cell switching. In other words, the method described in U.S. Provisional Patent Application No. 63 / 459,035 and the above method can be used to start a timer (when an activation command is received), and when the UE is determined to have successfully connected to the new target cell, the timer (referred to as timer T in some examples) can be restarted using the features described herein.

[0224] In one example, the timer T may monitor all TCI states for one or more cells for which the UE has received an activation command prior to a cell handover.

[0225] In one example, a timer T may be configured for the TCI state of each candidate LTM cell.

[0226] In one example, a timer T may be configured for the TCI state of each candidate LTM cell, where the candidate LTM cell is a secondary (serving) cell (SCell) of the UE.

[0227] In one example, the timer T may be configured for each TCI state or each TCI state set of a candidate LTM cell. Whether the timer T is applicable may be configured using RRC signaling.

[0228] In one example, RRC signaling may be used to configure the timer T. The timer T configuration may be commonly configured for all LTM candidate cells, or the timer T may be configured in the LTM candidate cell configuration.

[0229] In one example, the timer T may be configured for a specific target BWP of the target cell.

[0230] In one example, upon receiving a new TCI state activation for at least one LTM cell, all configured timer(s) T may expire.

[0231] In one example, the timer T may have a value expressed in seconds or milliseconds or other time units. The timer T value may be expressed in reference signal periodicity values, such as, for example, 1, 2, 3 downlink reference signal periods. Example downlink reference signal periodicity may be 20ms, 40ms, etc. Examples of duration may be 128ms, 256ms, 512ms, 1024ms, etc. Note that these are just examples. The timer value may be configured by the network. The timer T value may be indicated using MAC / PHY signaling, such as, for example, MAC CE or DCI.

[0232] In one example, upon receiving a new TCI state activation or TCI state indication for intra-cell or inter-cell beam management in a new serving cell, all configured (multiple) timers T may expire.

[0233] In one example, when a new cell handover command is received after a previous cell handover without receiving a new TCI state activation for LTM, the timer may expire upon connecting to the new cell. In one example, when a new cell handover command is received after a previous cell handover without receiving a new TCI state activation for LTM, the timer may be restarted upon connecting to the new cell. In one example, when the UE connects to a new target cell, a timer may be started for the activated TCI state.

[0234] In one example, a timer may be configured to expire when a new indicated TCI state is received in the target cell.

[0235] In one example, the MAC CE providing TCI activation for LTM may include an indication of whether to start a timer after a cell switch.

[0236] In one example, the timer T may be configured in the MAC layer. In one example, the timer T may be configured at the RRC layer.

[0237] A timer may be started for a TCI state associated with a cell for which the UE has previously performed TA acquisition or acquired a TA value on at least a PRACH transmission.

[0238] In one example, the UE may be configured to indicate the target cell and / or one or more active TCI states associated with the target cell to the new serving cell.

[0239] In one example, the UE may be configured to start a timer for maintaining / retaining only the activated TCI state of the previous serving cell.

[0240] In one example, the target cell may explicitly indicate, for example in a downlink MAC CE / DCI, that the timer T will expire. In another example, the receipt of the message may cause the timer T to expire.

[0241] In one example, if the UE utilizes (falls back to) the RACH based LTM procedure (eg, due to inability to use the indicated TCI state in the cell handover command or / and due to timing advance acquisition), the timer T may not be (re)started.

[0242] In one example, if the UE utilizes (falls back to) the RACH based LTM procedure (e.g. due to inability to use the indicated TCI state in the cell handover command and / or due to timing advance acquisition), the timer T may expire if the timer is running.

[0243] In one example, if the UE determines that it is not necessary to measure the L1-RRP for LTM for a specific cell or beam (DL RS, such as SSB / CSI-RS), the timer T associated with the TCI state of the cell or beam (DL-RS) may expire. In some examples, if the UE determines that it is not necessary to measure or report the L1-RSRP for LTM (or other measurements for LTM), the timer T expires after the determination.

[0244] In one example, a timer (timer T) may be started for the intra-cell TCI state (serving cell beam management). In one example, a timer (timer T) may be started for the inter-cell beam management TCI state. A common timer T may be used to supervise the activity state of the LTM TCI state and the intra-cell / inter-cell TCI state. In another example, the timer may be specific to the intra-cell / inter-cell BM (e.g., timer T_intra / inter). In an example, the timer may be specific to the LTM TCI state supervision (e.g., timer T_LTM). Therefore, the timer may be common to the LTM and the intra-cell / inter-cell BM, or the timer may be separate. Similar configuration options apply to the timer T_intra / inter, for example, it may be specific to a cell or a set of cells. It may be specific to a TCI state or a set of TCI states. The TCI state for serving cell beam management (in the target cell / new serving cell) may be activated before cell switching. After connecting to the cell, the timer is started (or if the timer is running, it is restarted). While the timer is running, one or more transmission configuration indicator states are considered active for intra-cell and / or inter-cell beam management within the target cell. When the timer expires, the UE determines that the TCI state associated with the timer is deactivated. In inter-cell beam management, the UE can be configured to communicate with a cell that is not a serving cell (i.e., has a different PCI than the serving cell) when connected to the serving cell.

[0245] In a conventional LTM scenario, when beam switching (LTM cell switching based on beam switching) is performed to an active TCI state, the following problems arise:

[0246] • If the TCI state is deactivated immediately after handover, efficient (subsequent) LTM cell handover will be prevented.

[0247] ● If the new target cell always needs to deactivate the TCI state for a specific cell or cells, it will increase signaling overhead and improve resource utilization. This may also reduce the flexibility of network scheduling.

[0248] • Keeping some or all TCI states active after LTM cell handover may be beneficial in subsequent LTM situations.

[0249] ● However, if subsequent LTM cell handovers do not occur within a reasonable time frame after the first LTM cell handover, it is unclear how long the TCI state should remain active. TCI being active means that the UE is tracking the timing of the TCI state, which may consume UE resources unnecessarily if the TCI state remains active for a long time when it is not needed.

[0250] The features described herein may be used to enable keeping some or all TCI states active after an LTM cell switch, thereby enabling the UE to be quickly commanded to a new LTM cell (if necessary).

[0251] The features described herein may be used to enable a UE to be commanded to return to a previous serving cell.

[0252] The features described herein can be used to introduce a timer that enables the UE to stop monitoring old activated TCI states without an explicit message from the network; saving some network UE signaling overhead. This will also save UE power and resources, as the UE is not expected to continue tracking the timing of these TCI states indefinitely.

[0253] The features described herein may be used to supervise the active TCI state for LTM after the UE enters a new target LTM cell by a timer. When the UE successfully connects to the target cell using the TCI indicated in the cell handover command, a timer may be started. While the timer is running, the TCI state activated before the cell handover may remain active. When the timer T expires, the TCI state may be deactivated.

[0254] Some other options may include:

[0255] • The timer may monitor all TCI states of one or more cells for which the UE has received an activation command prior to cell handover.

[0256] • A timer may be configured for the TCI state of each candidate LTM cell.

[0257] • A timer may be configured for each TCI state or for each set of TCI states of a candidate LTM cell.

[0258] • A timer may be configured for a specific target BWP of the target cell.

[0259] • After receiving a new TCI state activation for at least one LTM cell, all configured timers may expire.

[0260] • For a TCI state associated with a cell for which the UE has previously performed TA acquisition or acquired a TA value on at least a PRACH transmission, a timer may be started.

[0261] • If the UE utilizes (falls back to) RACH based LTM procedure, then the timer T may not be started.

[0262] Using the features described in US Provisional Patent Application No. 63 / 459,035, TCI state activation can start a timer before a cell handover. Using the features described herein, a timer supervising the active TCI state can be started when the UE successfully connects to the (new) target, i.e., the HO / cell handover completion to the LTM target starts the timer.

[0263] U.S. Provisional Patent Application No. 63 / 459,035 provides a common understanding of candidate activated TCI states and actual activated TCI conditions at both the serving cell and the candidate target cell, and ensures that the UE only considers active TCI states in preparation for LTM cell switching. Using the features described herein, the TCI state can remain active after the LTM cell switch to prepare for the LTM cell switch. However, this may be to limit the tracking time of the TCI state; without unnecessarily consuming UE resources. The features described herein can be used to ensure efficient LTM cell switching, avoiding increases in signaling overhead and resource utilization, but maintaining flexibility in network scheduling.

[0264] For the UE, a timer T may be configured to monitor the active TCI state (for LTM) after the UE enters a new target LTM cell. After a cell switch (LTM), the UE may start the timer upon sending an RRC reconfiguration complete or receiving an acknowledgement of a UL-SCH transmission carrying an RRC reconfiguration complete. As long as the timer is running, the UE may consider the TCI state associated with the timer that was activated before the LTM cell switch for the LTM cell switch. When the timer expires, the UE no longer needs to consider the TCI state for the LTM cell switch.

[0265] For the target cell, when the UE successfully enters / connects to the new target cell, a timer T (timer T_network) may be started at the target cell. When the timer T_network is running, the target cell may assume that the UE has an active TCI state for indication. The indication may be that when the timer T_network expires, the target cell may determine that the TCI state is no longer active.

[0266] A timer T (timer T_network) may also be started on the source cell. The timer may be started when a cell handover command is provided or when the UE acknowledges it; thereby enabling a quick handover back to the previous serving cell. While the timer is running, the cell may assume that the UE has an active TCI state (or maintain a previously activated active TCI state).

[0267] In one example, the activated TCI state list may be sent by the source cell to the target cell, and then when the UE is connected to the cell, the target cell starts the timer T(T_network).

[0268] The features described herein may be used in conjunction with a network-side timer. The network (target cell) should be aware of what the active TCI state is at the UE (the timer T at the UE has not expired) so that the network (target cell) may indicate one of such activated TCI states for cell switching without activating it again. A method may be provided in which the UE indicates that an active TCI state is signaled to a target cell, wherein the UE may indicate information about LTM candidate cells and / or one or more active transmission configuration indicator states associated with the LTM candidate cells to a new serving cell. Another example may be provided in which a list of active TCI states for a UE (and associated candidate cells) may be sent from a source cell to a target cell, and the target cell may then start a network-side timer.

[0269] Also refer to Figure 5 According to an example embodiment, a method is provided, comprising: connecting a device to a target cell, as indicated by box 502; starting a timer associated with one or more transmission configuration indicator states, as indicated by box 504; determining that the one or more transmission configuration indicator states are active before connecting to the target cell, as indicated by box 506; and considering the one or more transmission configuration indicator states as active for at least one of lower layer mobility or intra-cell / inter-cell beam management within the target cell, based on the timer being running, as indicated by box 508.

[0270] The method may also include: when the timer expires, treating one or more transmission configuration indicator states associated with the timer as inactive for lower layer mobility. The device may include user equipment. Determining that the device is connected to the target cell may include: using the transmission configuration indicator indicated in the cell handover command to determine when the device is successfully connected to the target cell. Determining that the device is connected to the target cell may include: determining when the device sends an RRC reconfiguration completion, or when the device receives an acknowledgement of an uplink shared channel (UL-SCH) transmission carrying the RRC reconfiguration completion. Determining that the device is connected to the target cell may include: using a random access procedure to determine when the device is connected to the target cell. The start of the timer may include restarting the timer, wherein the timer includes: a timer previously started based on an activation command that has been received. The timer may monitor one or more transmission configuration indicator states for one or more LTM candidate cells, for which the device has received an activation command before the cell is switched to the target cell. The timer may be configured for the transmission configuration indicator state of each LTM candidate cell or set of candidate cells. The timer may be configured per transmission configuration indicator state or for a set of transmission configuration indicator states for each LTM candidate cell. The use of the timer may be determined based on RRC signaling. The timer may be configured for a specific target BWP of the LTM candidate cell. The method may also include: expiring one or more configured timers based on receiving a new transmission configuration indicator state activation for at least one LTM candidate cell. The method may also include: expiring one or more configured timers based on receiving a new TCI state activation for intra-cell or inter-cell beam management in a target cell, the target cell being a new serving cell. The method may also include: expiring one or more timers after connecting to a new cell based on receiving a new cell handover command after a previous cell handover without receiving a new TCI state activation for LTM. The method may also include: expiring the timer based on receiving a new indicated transmission configuration indicator state in the target cell. The method may also include: receiving a MAC CE providing a transmission configuration indicator activation for LTM, the transmission configuration indicator activation including an indication of whether to start a timer after a cell handover. The method may also include: starting a timer for a transmission configuration indicator state associated with a cell in which the device previously performed at least one PRACH transmission for TA acquisition or acquired a TA value. The method may also include: the device indicating the LTM candidate cell and / or one or more active transmission configuration indicator states associated with the LTM candidate cell to the new serving cell. The method may also include: starting a timer for maintaining or retaining only the activated transmission configuration indicator state of the previous serving cell.The method may also include: receiving an explicit indication from the target cell that the timer is about to expire. The explicit indication may be received in a downlink MAC CE / DCI message. Receiving the message may cause the timer to expire. The method may also include: when the timer is running, when the device utilizes a RACH-based LTM process, causing the timer to expire. The method may also include: when the device determines that it is not necessary to measure the L1-RSRP for the LTM for the specific cell or beam, causing the timer associated with the specific cell or beam to expire.

[0271] According to an example embodiment, a method may be provided, comprising: determining that a device is connected to a target cell; starting a timer associated with one or more transmission configuration indicator states; determining that the one or more transmission configuration indicator states were active before connecting to the target cell; and based on the timer being running, considering the one or more transmission configuration indicator states to be active for lower layer mobility.

[0272] According to an example embodiment, a method may be provided, comprising: determining that a device is connected to a target cell; starting a timer associated with one or more transmission configuration indicator states; determining that the one or more transmission configuration indicator states are active before connecting to the target cell; and based on the timer being running, considering the one or more transmission configuration indicator states to be active for intra-cell / inter-cell beam management within the target cell.

[0273] According to an example embodiment, a device may be provided, comprising: at least one processor; and at least one non-volatile memory storing instructions, which, when executed together with the at least one processor, cause the device to perform: connecting the device to a target cell; starting a timer associated with one or more transmission configuration indicator states; determining that the one or more transmission configuration indicator states are active before connecting to the target cell; and based on the timer being running, treating the one or more transmission configuration indicator states as active for at least one of lower layer mobility or intra-cell / inter-cell beam management within the target cell.

[0274] The instructions, when executed together with at least one processor, may cause the device to perform: when the timer expires, treating one or more transmission configuration indicator states associated with the timer as inactive for lower layer mobility. The device may include a user equipment. The device may be configured so that determining that the device has been connected to the target cell includes: using the transmission configuration indicator indicated in the cell handover command to determine when the device has successfully connected to the target cell. The device may be configured so that determining that the device has been connected to the target cell includes: determining when the device sends an RRC reconfiguration completion, or when the device receives an acknowledgment of an uplink shared channel (UL-SCH) transmission carrying the RRC reconfiguration completion. The device may be configured so that determining that the device has been connected to the target cell includes: using a random access procedure to determine when the device is connected to the target cell. The device may be configured so that starting the timer includes restarting the timer, wherein the timer includes: a timer previously started based on an activation command that has been received. The device may be configured so that the timer monitors one or more transmission configuration indicator states for one or more LTM candidate cells, for which the device has received an activation command before the cell is switched to the target cell. The apparatus may be configured such that a timer is configured for a transmission configuration indicator state for each LTM candidate cell or a set of candidate cells. The apparatus may be configured such that a timer is configured according to a transmission configuration indicator state or is configured for a transmission configuration indicator for each LTM candidate cell. The apparatus may be configured such that the use of the timer is also determined based on RRC signaling. The apparatus may be configured such that the timer is configured for a specific target BWP for an LTM candidate cell. The instructions, when executed together with at least one processor, may cause the apparatus to execute activation based on receiving a new transmission configuration indicator state for at least one LTM candidate cell, so that one or more configured timers expire. The instructions, when executed together with at least one processor, may cause the apparatus to execute activation based on receiving a new TCI state for intra-cell or inter-cell beam management in a target cell, so that one or more configured timers expire, wherein the target cell is a new serving cell. The instructions, when executed together with at least one processor, may cause the apparatus to execute activation based on receiving a new cell handover command after a previous cell handover without receiving a new TCI state for LTM, so that one or more timers expire after connecting to a new cell. The instructions, when executed together with at least one processor, may cause the apparatus to perform a transmission configuration indicator state based on a new indication received in a target cell, causing a timer to expire. The instructions, when executed together with at least one processor, may cause the apparatus to perform receiving a MAC CE that provides a transmission configuration indicator activation for the LTM, the transmission configuration indicator activation including an indication of whether to start a timer after a cell handover.The instructions, when executed together with at least one processor, may cause the device to start a timer for a transmission configuration indicator state associated with a cell in which the device previously performed at least one PRACH transmission for TA acquisition or has acquired a TA value. The instructions, when executed together with at least one processor, may cause the device to indicate an LTM candidate cell and / or one or more active transmission configuration indicator states associated with the LTM candidate cell to a new serving cell. The instructions, when executed together with at least one processor, may cause the device to start a timer for maintaining or retaining only the activated transmission configuration indicator state of the previous serving cell. The instructions, when executed together with at least one processor, may cause the device to receive an explicit indication from a target cell that the timer is about to expire. The explicit indication may be received in a downlink MAC CE / DCI message. Receiving the message may cause the timer to expire. The instructions, when executed together with at least one processor, may cause the device to expire the timer when the timer is running and when the device utilizes a RACH-based LTM process. The instructions, when executed together with at least one processor, may cause the apparatus to execute, when the apparatus determines that it is not necessary to measure L1-RSRP for LTM for the specific cell or beam, expiring a timer associated with the specific cell or beam.

[0275] According to an example embodiment, an apparatus may be provided, comprising: a component for connecting the apparatus to a target cell; a component for starting a timer associated with one or more transmission configuration indicator states; a component for determining that the one or more transmission configuration indicator states are active before connecting to the target cell; and a component for treating the one or more transmission configuration indicator states as active for at least one of lower layer mobility or intra-cell / inter-cell beam management within the target cell based on the timer being running.

[0276] According to an example embodiment, a non-volatile program storage device readable by an apparatus may be provided, the non-volatile program storage device tangibly implementing an instruction program executable by the apparatus to perform operations, the operations including: connecting the apparatus to a target cell; starting a timer associated with one or more transmission configuration indicator states; determining that the one or more transmission configuration indicator states are active before connecting to the target cell; and based on the timer being running, treating the one or more transmission configuration indicator states as active for at least one of lower layer mobility or intra-cell / inter-cell beam management within the target cell.

[0277] Also refer to Figure 6According to an example embodiment, a method may be provided, including: as indicated by block 602, determining that a user equipment is connected to a target cell; as indicated by block 604, based on determining that the user equipment is connected to the target cell, starting a timer for the target cell (where the target cell may be a serving cell) using a network device; and when the timer is running, treating one or more transmission configuration indicator states for the user equipment as active using the network device for the target cell (where the target cell may be a serving cell), as indicated by block 606. The method may also include: based on the expiration of the timer, treating one or more transmission configuration indicator states for the user equipment as inactive using the network device for the target cell (where the target cell may be a serving cell).

[0278] According to an example embodiment, an apparatus may be provided, comprising: at least one processor; and at least one non-volatile memory storing instructions, the instructions, when executed together with the at least one processor, causing the apparatus to perform: determining that a user equipment has been connected to a target cell; based on determining that the user equipment has been connected to the target cell, starting a timer for the target cell using a network device of the apparatus; while the timer is running, using a network device for a serving cell, treating one or more transmission configuration indicator states for the user equipment as active. The instructions, when executed together with the at least one processor, may cause the apparatus to perform, based on expiration of the timer, treating one or more transmission configuration indicator states for the user equipment as inactive using a network device for a serving cell.

[0279] Also refer to Figure 7 According to an example embodiment, a method may be provided, including: based on at least one of the following items: sending a cell handover command to a user equipment in a source cell for handover to a target cell, or receiving a confirmation of a cell handover command from the user equipment for handover to the target cell, as indicated by block 702, starting a timer for the source cell (where the source cell may be a serving cell) using a network device of the device; and as indicated by block 704, while the timer is running, using the network device for the source cell (where the source cell may be a serving cell), treating one or more transmission configuration indicator states for the user equipment as active. The method may also include: based on the expiration of the timer, using the network device for the source cell, treating the one or more transmission configuration indicator states as inactive.

[0280] According to an example embodiment, an apparatus may be provided, comprising: at least one processor; and at least one non-volatile memory storing instructions, the instructions, when executed together with the at least one processor, causing the apparatus to perform: based on at least one of the following items: sending a cell handover command to a user equipment in a serving cell for handover to a target cell, or receiving a confirmation of the cell handover command from the user equipment for handover to the target cell, starting a timer for the serving cell using a network device of the apparatus; and when the timer is running, treating one or more transmission configuration indicator states for the user equipment as active using the network device for the serving cell. The instructions, when executed together with the at least one processor, may cause the apparatus to perform, based on expiration of the timer, treating one or more transmission configuration indicator states as inactive using the network device for the serving cell.

[0281] An example may be provided with a method comprising: determining that a device is connected to a target cell; based on determining that the device is connected to the target cell, starting a timer, wherein the timer is associated with one or more transmission configuration indicator states; after determining that the device is connected to the target cell, determining whether the one or more transmission configuration indicator states were active before the device was connected to the target cell; and based on the timer being running and based on determining that the one or more transmission configuration indicator states were active before the device was connected to the target cell, treating the one or more transmission configuration indicator states as active for lower layer mobility, or intra-cell / inter-cell beam management within the target cell.

[0282] The term "non-transitory" as used herein is a restriction on the medium itself (ie, tangible, not a signal), not on the persistence of data storage (eg, RAM vs. ROM).

[0283] As used in this application, the term "circuitry" may refer to one or more or all of the following:

[0284] (a) hardware circuit implementations only (such as implementations using only analog and / or digital circuitry); and

[0285] (b) a combination of hardware circuitry and software such as (where applicable):

[0286] (i) a combination of analog and / or digital hardware circuits and software / firmware, and

[0287] (ii) any portion of hardware processor(s) (including digital signal processor(s)), software and memory(s) with software that work together to enable a device (such as a mobile phone or server) to perform various functions, and

[0288] (iii) Hardware circuits and / or processor(s), such as microprocessor(s) or portions of microprocessor(s), that require software (e.g., firmware) to operate, but which may not be present when not required for operation.

[0289] This definition of circuitry applies to all uses of the term in this application, including in any claims. As a further example, as used in this application, the term circuitry would also cover an implementation of only a hardware circuit or processor (or multiple processors) or a portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. For example, if applicable to a particular claim element, the term circuitry would also cover a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or network device.

[0290] It should be understood that the foregoing description is illustrative only. Various substitutions and modifications may be envisioned by those skilled in the art. For example, the features listed in the various dependent claims may be combined with each other in any suitable combination (multiple). In addition, features from the different embodiments described above may be selectively combined into new embodiments. Therefore, this description is intended to include all such substitutions, modifications and variations that fall within the scope of the appended claims.

Claims

1. A device for communication, comprising: at least one processor; as well as at least one non-transitory memory storing instructions that, when executed with the at least one processor, cause the apparatus to perform: connecting the device to a target cell; starting a timer associated with one or more transmission configuration indicator states; determining that the one or more transmission configuration indicator states are active prior to connecting to the target cell; as well as Based on the timer being running, the one or more transmission configuration indicator states are considered active for at least one of lower layer mobility or intra-cell / inter-cell beam management within the target cell.

2. The apparatus of claim 1 , wherein the instructions, when executed together with the at least one processor, cause the apparatus to perform: when the timer expires, treating the one or more transmission configuration indicator states associated with the timer as inactive for lower layer mobility.

3. The apparatus according to any one of claims 1 to 2, wherein the apparatus comprises a user equipment.

4. The apparatus according to any one of claims 1 to 3, wherein the determining that the apparatus is connected to the target cell comprises: A transmission configuration indicator indicated in a cell handover command is used to determine when the device is successfully connected to the target cell.

5. The apparatus according to claim 4, wherein the determining that the apparatus is connected to the target cell comprises: Determining when the apparatus sends an RRC reconfiguration complete or when the apparatus receives an acknowledgement of an uplink shared channel (UL-SCH) transmission carrying the RRC reconfiguration complete.

6. The apparatus according to claim 4, wherein the determining that the apparatus is connected to the target cell comprises: A random access procedure is used to determine when the device connects to a target cell.

7. The apparatus according to any one of claims 1 to 6, wherein the starting of the timer comprises restarting the timer, wherein the timer comprises: A timer that was previously started based on an activate command having been received.

8. An apparatus according to any one of claims 1 to 7, wherein the timer monitors one or more transmission configuration indicator states for one or more LTM candidate cells, for which the apparatus has received an activation command before the cell is switched to the target cell.

9. The apparatus according to any one of claims 1 to 8, wherein the timer is configured for a transmission configuration indicator state of each LTM candidate cell or candidate cell set.

10. The apparatus according to any one of claims 1 to 9, wherein the timer is configured per transmission configuration indicator state or a transmission configuration indicator state set for each LTM candidate cell.

11. The apparatus according to any one of claims 1 to 10, wherein the use of the timer is further determined based on RRC signaling.

12. The apparatus according to any one of claims 1 to 11, wherein the timer is configured for a specific target BWP of the LTM candidate cell.

13. An apparatus according to any one of claims 1 to 12, wherein the instructions, when executed together with the at least one processor, cause the apparatus to execute based on receiving a new transmission configuration indicator state activation for at least one LTM candidate cell, causing one or more configured timers to expire.

14. An apparatus according to any one of claims 1 to 13, wherein the instructions, when executed together with the at least one processor, cause the apparatus to execute based on receiving a new TCI state activation for intra-cell or inter-cell beam management in a target cell, causing one or more configured timers to expire, wherein the target cell is a new serving cell.

15. An apparatus for communication, comprising: at least one processor; as well as at least one non-transitory memory storing instructions that, when executed with the at least one processor, cause the apparatus to perform: Determining that the user equipment is connected to the target cell; Based on the determination that the user equipment is connected to the target cell, starting a timer for the target cell using a network device of the apparatus; While the timer is running, the one or more transmission configuration indicator states for the user equipment are considered active by the network equipment for the target cell.

16. The apparatus of claim 15, wherein the instructions, when executed together with the at least one processor, cause the apparatus to execute, based on expiration of the timer, utilizing the network device for the target cell, treating the one or more transmission configuration indicator states for the user equipment as inactive.

17. The apparatus according to any one of claims 15 to 16, wherein the target cell is a serving cell.

18. An apparatus for communication, comprising: at least one processor; as well as at least one non-transitory memory storing instructions that, when executed with the at least one processor, cause the apparatus to perform: Based on at least one of the following items: sending a cell handover command to a user equipment in a source cell for handover to a target cell, or receiving a confirmation of the cell handover command from the user equipment for handover of the user equipment to the target cell, starting a timer for the source cell using a network device of the apparatus; as well as While the timer is running, one or more transmission configuration indicator states for the user equipment are considered active by the network equipment for the source cell.

19. The apparatus of claim 18, wherein the instructions, when executed with the at least one processor, cause the apparatus to execute, based on expiration of the timer, utilizing the network device for the source cell, to deem the one or more transmission configuration indicator states as inactive.

20. The apparatus according to any one of claims 18 to 19, wherein the source cell is a previous serving cell of the user equipment.

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