Cell DTX / DRX interacting with Layer 1 / Layer 2 trigger mobility

Abstract

Exemplary embodiments of this disclosure relate to the interaction of cell discontinuous transmit (DTX) / discontinuous receive (DRX) with Layer 1 / Layer 2 (L1 / L2) trigger mobility (LTM). According to embodiments, the system may include a serving distribution unit (DU). The serving DU may be configured to add at least one LTM-specific active period to at least one cell DTX / DRX cycle associated with a serving cell, provide at least one user equipment (UE) with information about at least one additional active period, and provide at least one UE with a media access control (MAC) control element (CE) during at least one additional active period. The MAC CE may include a cell switching command that instructs the UE to perform an LTM cell switching from the serving cell to a target cell.

Description

Technical Field

[0001] Cross-Reference to Related Applications This application claims priority from Indian Provisional Patent Application No. 202341052152, entitled "A SYSTEM AND METHOD FOR CELL DTX / DRX INTERWORKING WITH LAYER1 / LAYER2 TRIGGERED MOBILITY", filed with the Indian Patent Office on August 3, 2023, the entire disclosure of which is incorporated herein by reference.

[0002] Exemplary embodiments of the present disclosure relate to interworking between cell Discontinuous Transmission (DTX) / Discontinuous Reception (DRX) and Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM).

Background Art

[0003] Various features and mechanisms have been introduced to improve the performance of telecommunication networks. In particular, one or more technical specifications (e.g., Release 18) provided by the 3rd Generation Partnership Project (3GPP®) standardization organization describe mechanisms and procedures for Layer 1 / Layer 2 (L1 / L2) triggered mobility (LTM) to reduce mobility latency. Furthermore, one or more 3GPP technical specifications (e.g., Release 18) also describe concepts and mechanisms for cell Discontinuous Transmission (DTX) / Discontinuous Reception (DRX) for network energy saving. A cell serving user equipment (UE) may be configured with cell DTX / DRX for energy saving purposes, and the UE may be configured with LTM to reduce mobility latency.

Summary of Invention

Means for Solving the Problems

[0004] Exemplary embodiments of this disclosure provide systems, apparatus, methods, etc., for facilitating cell DTX / DRX interactions with LTMs.

[0005] According to the embodiment, the system may include a distributed unit (DU). The serving DU may be configured to add at least one Layer 1 (L1) / Layer 2 (L2) trigger mobility (LTM) specific active period to at least one cell discontinuous transmit (DTX) / discontinuous receive (DRX) cycle associated with a serving cell, to provide at least one user equipment (UE) with information about at least one additional active period, and to provide at least one Media Access Control (MAC) control element (CE) to at least one UE during at least one additional active period. The MAC CE may include a cell switching command that instructs at least one UE to perform an LTM cell switch from the serving cell to a target cell.

[0006] According to embodiments, the method may include adding at least one Layer 1 (L1) / Layer 2 (L2) Trigger Mobility (LTM) specific active period to at least one cell discontinuous transmit (DTX) / discontinuous receive (DRX) cycle associated with a serving cell; providing at least one user equipment (UE) with information about at least one added active period; and providing at least one UE with a media access control (MAC) control element (CE) during at least one added active period. The MAC CE may include a cell switching command that instructs at least one UE to perform an LTM cell switch from a serving cell to a target cell.

[0007] According to one embodiment, a non-transient computer-readable recording medium may record therein instructions that can be executed by at least one network node to cause at least one network node to perform a method. The method may include adding at least one Layer 1 (L1) / Layer 2 (L2) trigger mobility (LTM) specific active period to at least one cell discontinuous transmit (DTX) / discontinuous receive (DRX) cycle associated with a serving cell; providing at least one user device (UE) with information about at least one added active period; and providing at least one UE with a media access control (MAC) control element (CE) during at least one added active period. The MAC CE may include a cell switching command that instructs the UE to perform an LTM cell switching from a serving cell to a target cell.

[0008] Further embodiments may be partially described below, partially revealed therein, or realized by the practice of the embodiments presented in this disclosure.

[0009] Features, advantages, and importance of exemplary embodiments of this disclosure are described below with reference to the accompanying drawings, where similar reference numerals in the drawings indicate similar elements. [Brief explanation of the drawing]

[0010] [Figure 1] This is an example diagram of a cell DTX / DRX cycle. [Figure 2] This is a block diagram of a general-purpose system architecture in which one or more exemplary embodiments may be implemented. [Figure 3] This is a flowchart illustrating an exemplary method for adding at least one active period and providing an LTM cell switching command, according to one or more embodiments. [Figure 4] This is a flowchart illustrating an exemplary method for receiving and performing an LTM cell switching command, according to one or more embodiments. [Figure 5] This figure shows a flow sequence of an exemplary embodiment in which the operations of the methods in Figures 3 and 4 are performed in sequence according to one or more embodiments. [Figure 6A] This figure shows a flow sequence of an exemplary use case for facilitating cell DTX / DRX interaction with LTM by adding multiple active periods based on an active period coefficient, according to one or more embodiments. [Figure 6B] This figure shows a flow sequence of an exemplary use case for facilitating cell DTX / DRX interaction with LTM by adding multiple active periods based on an active period coefficient, according to one or more embodiments. [Figure 7] This figure shows an exemplary cell DTX / DRX cycle for an exemplary use case associated with the flow sequences in Figures 6A and 6B, according to one or more embodiments. [Figure 8] This figure shows a flow sequence of an exemplary use case for facilitating cell DTX / DRX interaction with LTM by adding at least one active period based on predicted LTM cell switching, and providing information on at least one additional active period via MAC CE, using one or more embodiments. [Figure 9] This figure shows a flow sequence of an exemplary use case for facilitating cell DTX / DRX interaction with LTM by adding at least one active period based on predicted LTM cell switching, and providing information on the at least one added active period via RRC signaling, according to one or more embodiments. [Figure 10] This is a diagram of an exemplary cell DTX / DRX cycle for an exemplary use case associated with the flow sequences in Figures 8 and 9, according to one or more embodiments. [Figure 11]This figure shows a flow sequence of an exemplary use case in which an LTM fallback configuration is provided to the UE by one or more embodiments. [Figure 12] This is a block diagram of exemplary components of a network node according to one or more embodiments. [Figure 13] This is a block diagram of an exemplary configuration of a network node according to one or more embodiments. [Figure 14] This is a diagram illustrating an exemplary environment in which the systems and / or methods described herein may be implemented. [Modes for carrying out the invention]

[0011] A detailed description of exemplary embodiments follows with reference to the accompanying drawings. The same reference numerals in different drawings may identify the same or similar elements.

[0012] The foregoing disclosures provide examples and explanations, but are not intended to be exhaustive or to limit implementations to the exact forms disclosed. Modifications and variations may be possible in light of the foregoing disclosures or may be derived from the practice of implementations. Furthermore, one or more features or components of one embodiment may be incorporated into or combined with another embodiment (or one or more features of another embodiment). In addition, it should be understood that in the descriptions of operation provided below, one or more operations may be omitted, one or more operations may be added, one or more operations may be performed (at least partially) simultaneously, and the order of one or more operations may be changed.

[0013] It will be apparent that the systems and / or methods described in the present specification can be implemented in different forms of hardware, firmware, or a combination of hardware and software. The actual dedicated control hardware or software code used to implement these systems and / or methods is not limited to the described implementations. Accordingly, the operation and behavior of the systems and / or methods are described herein without reference to specific software code. It is understood that software and hardware can be designed to implement the systems and / or methods based on the description herein.

[0014] Even if specific combinations of features are disclosed herein, these combinations do not limit the disclosure of possible implementations. In fact, many of these features may be combined in ways not specifically disclosed herein.

[0015] No element, act, or instruction used in the present specification should be construed as critical or essential unless explicitly described as such. Also, as used herein, the articles "a" and "an" are intended to include one or more items and may be used interchangeably with "one or more". Where only one item is intended, the term "one" or similar language is used. Furthermore, terms such as "has", "have", "having", "include", "including" as used herein are intended to be open-ended terms. Further, the phrase "based on" is intended to mean "based at least in part on" unless otherwise specifically stated. Further, expressions such as "at least one of [A] and [B]", "[A] and / or [B]", or "at least one of [A] or [B]" should be understood to include only A, only B, or both A and B.

[0016] It should be noted that the description of the exemplary embodiments of the present disclosure may include terms and names defined in one or more standardization organizations such as the 3rd Generation Partnership Project (3GPP) standardization organization and the European Telecommunications Standards Institute (ETSI) standardization organization. For example, terms such as "cell DTX / DRX", "LTM cell switching", "MAC CE", "PDCCH", "RRC reconfiguration message", "F1AP UE context modification request message", "UE context modification procedure", "DCI", "RNTI", "F1 interface", "RRC reconfiguration complete message", and related features and operations should be interpreted as consistent with those specified in one or more 3GPP technical specifications or the like, unless otherwise stated.

[0017] Further, although some embodiments of the present disclosure may be described herein with reference to "gNodeB" and related components in 5G systems, it can be understood that the scope of the present disclosure should not be limited thereto. Specifically, the exemplary embodiments of the present disclosure may also be applied to any suitable network element in any suitable telecommunication system such as a 4G LTE system, a 6G system, etc.

[0018] In addition, although the present specification describes a case where a central unit (CU) communicates with user equipment (UE), it can be understood that such description is not necessarily limited to the CU being directly connected or communicating with the UE. Rather, it is contemplated that the CU may communicate with the UE via any suitable channel or element, for example via a distributed unit (DU), a network cell, etc., without departing from the scope of the present disclosure. Similarly, although the present specification describes that a DU may communicate with a UE, it can be understood that such description is not necessarily limited to the DU being directly connected or communicating with the UE for the same reason.

[0019] Furthermore, the term “Cell DTX / DRX” is intended to specify that “DTX / DRX” is associated with a network cell. In this regard, while several exemplary embodiments may be described herein by reference to “Cell DTX / DRX,” these exemplary embodiments may also apply equally to “Cell DTX” only or “Cell DRX” only without departing from the scope of this disclosure. For example, some embodiments describe that one or more active periods may be added to one or more Cell DTX / DRX cycles, and it can be understood that one or more active periods may be added to only one or more Cell DTX cycles, or to only one or more Cell DRX cycles.

[0020] As telecommunications network technology evolves, network elements within a telecommunications network may be broken down into multiple entities. Specifically, architectures defined and broken down by one or more 3GPP technical specifications break down a base station into multiple logical entities. For example, a g-node B (gNB) may be broken down into a central unit (CU) and a distributed unit (DU). Similarly, a single CU may be broken down into a CU control plane (CU-CP) and a CU user plane (CU-UP).

[0021] A CU-CP can host the Radio Resource Control (RRC) layer and PDCP-c, while a CU-UP can host the Service Data Adaptation Protocol (SDAP) layer and PDCP-u. In this regard, PDCP-c may refer to the first mode of the Packet Data Convergence Protocol (PDCP) layer, which primarily processes control plane data, and PDCP-u may refer to the second mode of the PDCP layer, which primarily processes user plane data. Meanwhile, a single DU can host or service multiple network cells, the Radio Link Control (RLC) layer, the Media Access Control (MAC) layer, and the Physical (PHY) layer. Scheduling operations may occur at the DU.

[0022] The concept and basic principles of Layer 1 / Layer 2 (L1 / L2) Triggered Mobility (LTM) are introduced in one or more 3GPP technical specifications (e.g., Release 18). Generally, LTM is a procedure in which a base station (e.g., gNB) receives one or more L1 measurements from a UE (e.g., in the form of one or more L1 measurement reports) and triggers a cell switching procedure based on the received L1 measurements. Specifically, the base station can change the serving cell of a UE by signaling the UE with a Media Access Control (MAC) control element (CE) containing a cell switching command. In response, the UE can switch from the serving cell to the target cell in accordance with the cell switching command.

[0023] For example, if the UE is configured as LTM, the UE can continuously monitor one or more RRM parameters (e.g., radio signal quality, signal strength, etc.) of one or more neighboring candidate cells and / or the serving cell. Accordingly, the UE can report one or more L1 measurements to the serving cell (or its associated base station), which can then use the one or more L1 measurements to determine whether one or more cell switching criteria have been met. For example, the serving cell (or its associated base station) can determine, based on one or more RRM parameters in one or more L1 measurements, whether the serving cell's signal quality is degraded or whether an adjacent candidate cell provides better signal quality. Based on the determination that one or more cell switching criteria have been met, the serving cell (or its associated base station) can send a MAC CE containing a cell switching command to the UE, instructing the UE to perform an LTM cell switch from the serving cell to the target cell.

[0024] To this end, LTM enables cell switching via L1 / L2 signaling without involving or affecting higher layers (e.g., Layer 3). Furthermore, LTM leverages L1 measurements to trigger or initiate optimized cell switching procedures, thereby facilitating seamless cell switching and mobility management for UEs as they move between different cells or access points within the telecommunications network.

[0025] On the other hand, mechanisms and procedures for cell discontinuous transmission (DTX) / discontinuous reception (DRX) are also described in one or more 3GPP technical specifications (e.g., Release 18). Generally, cell DTX / DRX is designed to optimize the power consumption of network cells by allowing network cells to periodically enter sleep and wake-up modes according to a predefined cycle.

[0026] By configuring a cell with DTX / DRX, the cell can enter a sleep mode for a certain period of time, and then wake up to transmit and / or receive data. Specifically, when a cell is configured with DTX / DRX, it can enter a sleep mode for a certain period of time, and then wake up again to transmit / receive data (if any), thereby effectively reducing the cell's power consumption. A cell configured with DTX / DRX can periodically repeat the transition between sleep mode and wake-up mode, and such a cycle of phenomena is sometimes called a "DTX / DRX cell cycle."

[0027] Figure 1 shows an example of a cell DTX / DRX cycle. As shown in Figure 1, the DRX cycle can be defined as a periodic repetition of an "active period" followed by an "inactive period". The x-axis of the figure can define the length of the cell DTX / DRX cycle (e.g., in units such as ms), and the y-axis of the figure can define the power consumption level when the cell is turned on during the active period. The pattern or configuration of the cell DTX / DRX (e.g., the length of the cell DTX / DRX cycle, the length of the active period, etc.) may be defined and adjustable by the network operator.

[0028] During the "active period," a cell configured with cell DTX / DRX can be turned on and then enter wake-up mode. Conversely, during the "inactive period," the cell can be turned off and then enter sleep mode. Therefore, in some implementations, the "active period" may also be called the "on period," and the "inactive period" may also be called the "off period." Furthermore, in some implementations, a device (e.g., user equipment) may be provided with or configured with cell DTX / DRX patterns. When cell DTX is configured and activated for a cell, the device does not monitor physical downlink control channel (PDCCH) opportunities and / or semi-persistent scheduling (SPS) opportunities during the cell DTX inactive period. Conversely, when cell DRX is configured and activated for a cell, the UE does not send configured grant (CG) resources or scheduling requests (SR) during the cell DRX inactive period. Therefore, the “active period” of a cell DTX / DRX cycle may refer to the period during which a device (e.g., UE) waits to receive data from a cell (e.g., PDCCH opportunity and / or SPS opportunity, etc.) and to send an SR or CG. The active period and cycle parameters may be common between cell DTX and cell DRX when both cell DTX and cell DRX are configured or activated. During the “active period,” transmissions / receptions of PDCCH, SPS, CG, scheduling requests (SR), periodic and semi-persistent CSI reports, etc., are unaffected for network energy saving purposes.

[0029] During the "inactive period," a cell configured with cell DTX / DRX enters wake-up mode (e.g., the RF module is turned on) and can determine whether there is data available for transmission and / or reception. If the cell detects data for transmission and / or reception, it remains awake and can begin transmitting and / or receiving data. On the other hand, if the cell does not detect any data for transmission and / or reception during the active period, it can enter sleep mode during the inactive period. In some implementations, instead of disabling all transmission / reception during the inactive period, the cell can disable specific transmission / reception, thereby providing limited transmission / reception. For example, a cell may be configured so that transmission and / or reception of certain periodic signals and / or channels (e.g., common channel / signal, UE-specific signal / channel, etc.) are not enabled during the inactive period. Ultimately, configuring a cell with cell DTX / DRX allows the cell to conserve power.

[0030] Considering the above, a base station (e.g., a gNB) can configure a cell with cell DTX / DRX and provide an LTM configuration to the UE so that the UE can be configured with LTM, thereby improving the performance of both the cell and the UE. Nevertheless, in the prior art, there are some drawbacks when the cell serving the UE (sometimes referred to herein as the “serving cell”) is configured with cell DTX / DRX and the UE is configured with LTM.

[0031] First, as previously mentioned, an LTM-configured UE needs to transmit one or more L1 measurements to the relevant base station in order to trigger an LTM cell switchover. In this regard, if the cell DRX is activated in the serving cell (to which the UE is connected), the serving cell cannot receive L1 measurements from the UE during the inactive period of the cell DRX cycle. Similarly, the UE can only transmit L1 measurements during the active period of the serving cell's cell DRX cycle. Consequently, an LTM cell switchover cannot be triggered in a timely manner when needed.

[0032] Furthermore, as mentioned above, the base station must provide the UE with an LTM cell switching command so that the UE can perform LTM cell switching based on it. In this regard, the base station can only send the LTM cell switching command to the UE during the active period of the cell DTX cycle. In other words, if an LTM cell switching is required but the base station determines that the serving cell is in an inactive / sleep mode, the base station cannot immediately send a MAC CE (including the LTM cell switching command) to the relevant UE until the serving cell wakes up within the next active period. Accordingly, delays in sending / receiving the LTM cell switching command will result in delays in the LTM cell switching, which may cause a Radio Link Failure (RLF). Moreover, since LTM is expected to provide a faster cell switching procedure compared to baseline Layer 3 (L3) handover, and base stations should send the LTM cell switching command as soon as possible, any delay at the base station sending the LTM cell switching command is counterproductive to the purpose of LTM.

[0033] In addition to the drawbacks mentioned above, the mechanisms for supporting cell DTX / DRX and LTM in the decomposed architecture remain unknown and unspecified at this time. For example, it is unclear how entities within the decomposed gNB (e.g., gNB-CU, gNB-DU, etc.) behave to enable proper execution of LTM when the serving cell is composed of cell DTX / DRX.

[0034] In this regard, exemplary embodiments of the present disclosure provide system architectures, mechanisms, procedures, etc., for facilitating cell DTX / DRX interaction with LTM, thereby enabling proper execution of LTM when the serving cell is configured with DTX / DRX.

[0035] Specifically, exemplary embodiments of the present disclosure provide a system, method, device, etc., that enables a base station (e.g., a DU) to provide one or more UEs with an LTM cell switching command in a timely manner, and enables one or more UEs to receive the LTM cell switching command in a timely manner, regardless of the initial cell DTX / DRX configuration of the serving cell, and to perform an LTM cell switching thereon. Ultimately, the LTM cell switching command may be provided to one or more UEs in a timely manner, thereby avoiding any delay in the LTM cell switching and mitigating the risk of RLF caused by a delayed LTM cell switching.

[0036] Furthermore, exemplary embodiments of this disclosure provide systems, methods, devices, etc., that enable one or more UEs to provide one or more L1 measurements to a base station (e.g., a DU) in a timely manner, and enable the base station to receive one or more L1 measurements in a timely manner. Accordingly, one or more L1 measurements may be provided to the base station in a timely manner, and an LTM cell switchover may be triggered in a timely manner.

[0037] Furthermore, operations associated with cell configuration may be performed in the CU, and cell switching may be performed autonomously in the DU without further interaction with higher layers. Accordingly, exemplary embodiments of this disclosure provide system architectures, mechanisms, procedures, etc., for facilitating cell DTX / DRX interaction with the LTM in a disassembled architecture, thereby enabling effective interaction between a serving cell configured with cell DTX / DRX and one or more UEs configured with LTMs in a disassembled architecture.

[0038] The features, advantages, and importance of the exemplary embodiments described above are only a part of this disclosure and are not intended to be exhaustive or to limit the scope of this disclosure.

[0039] Further description of the features, components, configurations, operations, and implementations of exemplary embodiments of the present disclosure, as well as the technical advantages associated therewith, is provided below.

[0040] General system architecture Figure 2 shows a block diagram of a general-purpose system architecture 200 in which one or more exemplary embodiments may be implemented. As shown in Figure 2, the system architecture 200 may include at least one base station 210, a plurality of cells 220, and at least one user equipment (UE) 230. The components and configurations shown in Figure 2 are merely examples of possible embodiments of the present disclosure, and without departing from the scope of the present disclosure, the system architecture may include more / fewer components than those shown, and / or the components may be arranged in a different manner than those shown.

[0041] The base station 210 may include at least one central unit (CU) 212 and a plurality of distributed units (DUs) 214-216. According to embodiments, the base station may include a g-node B (gNB) of 5G NR or a node in a Next Generation Radio Access Network (NG-RAN). In this case, CU212 may be a gNB-CU and DU214-216 may be gNB-DUs. Without departing from the scope of this disclosure, the base station 210 may also include any other suitable type of radio base station, such as an advanced node B (e-node B) of a 4G LTE network or a base station of a 6G network. Furthermore, communication between CU212 and DU214-216 may be performed via an F1 interface.

[0042] Depending on the embodiment, CU212 and DU214-216 may be defined in software form and deployed on one or more network nodes. For example, CU212 and DU214-216 may be deployed on one or more servers in the form of virtualized network functions (VNFs), containerized and / or cloud-native functions (CNFs).

[0043] In some embodiments, CU212, DU214, and / or DU216 may be deployed on the same network node (e.g., the same server) and / or located in similar geographical locations (e.g., deployed on different servers within the same data center). In some embodiments, CU212, DU214, and / or DU216 may be deployed on different network nodes and / or located in different geographical locations. For example, CU212 may be deployed on one or more central servers located away from UE230 (i.e., servers in one or more central data centers), while DU214-216 may be deployed on one or more edge servers located closer to UE230 (i.e., servers in one or more edge data centers). Similarly, DU214 and DU216 may be located in different geographical locations (e.g., deployed on different servers, etc.).

[0044] A description of exemplary network nodes in which CU212 and / or DU214-216 may be deployed is provided below with reference to Figures 12-13. A description of exemplary environments in which CU212 and / or DU214-216 may be deployed is provided below with reference to Figure 14. In this regard, it is conceivable that one or more operations associated with CU212 and DU214-216 described herein may be performed by one or more components of the relevant network nodes without departing from the scope of this disclosure.

[0045] DU214-216 can receive radio signals from end users (via one or more of UE230 and cell 220) and accordingly provide operations or support for lower layers of the protocol stack (e.g., Radio Link Control (RLC) layer, Media Access Control (MAC) layer, physical layer, etc.). As an example, DU214-216 can perform one or more scheduling operations. CU212 can communicatively couple DU214-216 to a core network (e.g., an Evolved Packet Core (EPC) network, a 5G core network, etc.) and receive radio signals from the DU, thereby providing operations or support for higher layers of the protocol stack (e.g., Packet Data Convergence (PDCP) layer, Radio Resource Control (RRC) layer, etc.). As an example, CU212 can provide one or more configurations to UE230 via RRC signaling.

[0046] According to the embodiments, a single CU can host or service multiple DUs. In the example in Figure 2, CU212 can host or service DU214 and DU216. In practice, it is conceivable that a CU can host or service fewer than two or more than two DUs without departing from the scope of this disclosure.

[0047] Continuing to refer to Figure 2, cell 220 may contain a plurality of cells 222–228. One or more of cells 222–228 may contain a macrocell, microcell, picocell, femtocell, or any other suitable type of network cell. Each of cells 222–228 may have an associated coverage area where at least one radio unit (RU), at least one antenna system, and any other suitable type of transport network element (TNE) may be deployed. According to the embodiment, one or more of cells 222–228 may consist of cell DRX and / or cell DTX.

[0048] In the following, the cell to which the UE230 is connected may be referred to as the “serving cell,” the cells near the UE230 and / or the serving cell may be referred to as “adjacent cells,” the cells that may be selectable (from one or more adjacent cells) for LTM cell switching may be referred to as “candidate cells” or “LTM candidate cells,” and the cell selected (from one or more candidate cells) to receive LTM cell switching may be referred to as the “target cell” or “LTM target cell.” Similarly, the DU that services or hosts the serving cell may be referred to as the “source DU” or “serving DU,” the DU that services or hosts the candidate cell may be referred to as the “candidate DU,” and the DU that services or hosts the target cell may be referred to as the “target DU.” The target cell / DU can be understood as the candidate cell / DU selected for LTM cell switching. One or more of the DUs may include an NG-RAN node DU.

[0049] According to the embodiments, a single DU can host or service multiple cells. For example, a DU can implement various wireless technologies such as Multiple-Input Multiple-Output (MIMO) and beamforming to optimize wireless communication between multiple cells and CUs. In the example in Figure 2, DU214 can host or service cells 222-224, and DU216 can host or service cells 226-228. Nevertheless, in practice, it is conceivable that a DU can host or service fewer than two or three or more cells without departing from the scope of this disclosure. Specifically, in some implementations, a single DU can host or service hundreds (e.g., 512) cells simultaneously at one time.

[0050] Continuing to refer to Figure 2, UE230 may include one or more devices that can be used by one or more end users to access a telecommunications network. For example, UE230 may include one or more computing devices (e.g., desktop computers, laptop computers, tablet computers, handheld computers, smart speakers, servers, etc.), mobile phones (e.g., smartphones, wireless phones, etc.), wearable devices (e.g., a pair of smart glasses or smartwatches), SIM-based devices, or any other suitable devices. According to the embodiment, UE230 may include a group of UEs such as multiple devices, apparatus, and equipment that are communicably coupled to the same cell (e.g., serving cell 222).

[0051] According to the embodiments, the UE230 may be configured in connected mode DRX (C-DRX) to save energy for the device. In this regard, the exemplary embodiments of the present disclosure are considered applicable to both situations in which the UE230 is configured in C-DRX and situations in which it is not.

[0052] One or more of cells 222-228 may be configured as cell DTX / DRX, and UE230 may be configured as LTM. The pattern or configuration of the cell DTX / DRX cycle may be common to multiple UEs associated with the cell (e.g., a group of UEs connected to a serving cell). For example, when UE230 includes a group of UEs, the group of UEs may experience the same / common cell DTX / DRX cycle as serving cell 222, since they are hosted or serviced by serving cell 222. According to an embodiment in which UE230 is configured as C-DRX, at least a portion of the on-period of the DRX cycle associated with UE230 may overlap with at least a portion of the active-period of the cell DTX / DRX cycle associated with serving cell 222. For example, the C-DRX periodicity may be a multiple or factor of the cell DTX / DRX periodicity, or vice versa.

[0053] During operation, the UE230 may be configured as an LTM and can connect to a serving cell 222 hosted or serviced by a serving DU214. The UE230 can then perform an LTM cell switch from serving cell 222 to another cell when necessary.

[0054] According to one embodiment, the UE230 can perform intra-DU LTM cell switching, and the UE230 can switch from a serving cell to a target cell serviced or hosted by the same serving DU (for example, switching from serving cell 222 to cell 224). According to another embodiment, the UE230 can perform inter-DU LTM cell switching, and the UE230 can switch from a serving cell to a target cell serviced or hosted by a different DU (for example, switching from serving cell 222 to cell 228). The type of cell switching and the associated target cell information are determined by the base station 210. For example, during the LTM preparation phase, the base station 210 (e.g., CU212, DU214, etc.) can select one or more LTM candidate cells from among several adjacent cells, and then prepare the LTM configuration for the selected LTM candidate cells and provide it to the UE230. Accordingly, during the LTM execution phase, the base station (e.g., DU214) can select a target cell from one or more LTM candidate cells and then provide information about the target cell to the UE230 in a cell switching command, which in turn allows the UE230 to perform a cell switch to the target cell.

[0055] An example of inter-DU cell switching is shown in Figure 2, in which UE230 switches from cell 222 (i.e., the serving cell) hosted / serviced by DU214 (i.e., the serving DU) to cell 228 (i.e., the target cell) hosted / serviced by DU216. In this example, it is assumed that serving cell 222 consists of cells DTX / DRX. A description of the exemplary operation associated with it is provided below.

[0056] During the startup process (e.g., initialization, activation, etc.), the serving cell 222 is provided with the cell DTX / DRX configuration (e.g., by serving DU214, CU212, etc.). The configuration associated with the cell DTX / DRX may be referred to herein as the “cell DTX / DRX configuration”. The cell DTX / DRX configuration may include, for example, periodicity, start slot / offset, active / inactive period configuration, and cell DTX / DRX cycle configuration. The cell DTX / DRX may be characterized by one or more principles defined in one or more 3GPP specifications (e.g., specifications provided by RAN WG2 (RAN2) of the 3GPP Technical Specifications Group Radio Access Networks (TSG RAN)).

[0057] Serving cell 222 may be configured as a cell DTX / DRX by applying a cell DTX / DRX configuration. For example, serving cell 222 may override the default on / off timer or power settings in the cell DTX / DRX configuration, thereby enabling cell DTX / DRX in serving cell 222. According to embodiments, the patterns or configurations of cell DTX and cell DRX may be different. For example, the patterns of the cell DTX cycle and the cell DRX cycle may be different. In this case, serving cell 222 can configure the cell DTX cycle and the cell DRX cycle separately. Conversely, the patterns or configurations for cell DTX and cell DRX may be common when both are configured. For example, cell DTX and cell DRX may have the same configuration during the active period, may have common cycle parameters, etc. Cell DTX and cell DRX may be configured and activated separately. According to embodiments, serving cell 222 may include multiple cell DTX / DRX configurations or patterns. For example, serving cell 222 may have two cell DTX / DRX configurations or patterns. Furthermore, different cells may have the same or different cell DTX / DRX configurations or patterns. For example, serving cells 222 and 224, both hosted or serviced by serving DU 214, may have the same / different cell DTX / DRX configurations or patterns.

[0058] When UE230 is first connected to serving cell 222, base station 210 (e.g., CU212) may provide (UE230) with a configuration that enables UE230 to be configured as an LTM when utilized by UE230. The configuration associated with the LTM may be referred to herein as the “LTM configuration”. The LTM configuration may include, for example, cell identification information (e.g., cell ID of candidate cells, cell ID of target cells, etc.), radio bearers of the cell, measurement configuration (e.g., measurement gap, type of measurement such as in-frequency measurement or inter-frequency measurement, etc.), reporting configuration, RRC configuration, etc.

[0059] According to one embodiment, the base station 210 (e.g., DU214) can provide the UE230 with information on the cell DTX / DRX cycle associated with a serving cell (e.g., cell 222) based on the determination that the UE230 is configured in LTM mode. Accordingly, the UE230 can align or adjust the periodic L1 measurements and L1 measurement reports according to the cell DTX / DRC cycle based on the cell DTX / DRC cycle information. In this way, the UE230 can provide the serving cell with L1 measurements in a timely manner during the active period of the cell DTX / DRX cycle, thereby triggering an LTM cell switchover in a timely and appropriate manner when needed.

[0060] Furthermore, when UE230 first enters a connected state, UE230 may receive an LTM configuration associated with the serving cell and / or one or more adjacent cells from base station 210 (e.g., CU212). According to the embodiment, UE230 may further receive a C-DRX configuration associated with UE230 from base station (e.g., CU212). UE230 may receive the C-DRX configuration in the same / separate message as the LTM configuration. According to the embodiment, UE230 may receive the LTM configuration and / or C-DRX configuration in one or more Radio Resource Control (RRC) messages, such as one or more RRC reconfiguration messages. Accordingly, UE230 may be configured with LTM based on the LTM configuration. Furthermore, if UE230 receives a C-DRX configuration, UE230 may be configured with C-DRX based on the C-DRX configuration.

[0061] According to the embodiment, a base station 210 (e.g., CU212, DU214) can provide the UE230 with a cell DTX / DRX configuration (or information associated therewith). Accordingly, the UE230 can coordinate or perform one or more operations using the cell DTX / DRX configuration. For example, the UE230 may be configured to coordinate or align periodic L1 measurements and L1 measurement reporting based on the cell DTX / DRX configuration.

[0062] Furthermore, the UE230 may not monitor PDCCH for dynamic authorization / allocation for new transmissions during cell DTX inactivity periods, or may not monitor SPS opportunities during cell DTX inactivity periods, etc. Furthermore, the UE230 may not transmit on CG resources or opportunities during cell DRX inactivity periods, or may not transmit on SR opportunities during cell DRX inactivity periods, etc.

[0063] The aforementioned characteristics (e.g., not monitoring PDCCH during inactive periods, not transmitting SRs during inactive periods) may only be applicable when UE230 is in the RRC_CONNECTED state, and may not affect random access procedures, synchronization signal block (SSB) transmissions, paging, and system information broadcasts. For example, as soon as base station 210 recognizes that a particular event exists (e.g., an emergency call, public safety-related services, multimedia priority services (MPS), mission critical services (MCS)), base station 210 may release, deactivate, or disable the cell DTX / DRX in serving cell 222 to ensure that the relevant services are not affected.

[0064] As another example, if the UE230 is configured with C-DRX, the UE230 can utilize the cell DTX / DRX configuration to adjust the C-DRX configuration, thereby improving performance. For example, the UE230 can align its DRX cycles with the cell DTX cycles, omit one or more DRX cycles, initiate a DRX offset, and so on. According to the embodiment, the UE230 can adjust at least one on period of the relevant DRX cycle to at least partially overlap with at least one active period of the cell DTX / DRX cycle.

[0065] When configured with LTM (and, where applicable, adjusting the relevant configuration according to the cell DTX / DRX configuration), the UE230 can perform one or more measurements sequentially (or periodically) on the serving cell 222 and / or one or more adjacent cells (e.g., cells 224-228) and then provide the measurements to the base station 210, so that the base station can determine which of the adjacent cells is suitable to be selected for LTM cell switching. For example, the UE230 can perform one or more measurements on the Reference Signal Received Power (RSRP) (or other appropriate parameters) of the serving cell and / or adjacent cells and then provide or report one or more RSRP measurements to the CU212 via Layer 3 (L3). Thus, measurements reported via L3 may also be called "L3 measurements." L3 measurements may include, for example, SSB-based L3 measurements, Channel State Information Reference (CSI-RS)-based L3 measurements, etc. Since L3 measurements can be transmitted to CU212 via RRC reports (which may include, for example, RRC measurement reports), L3 measurements may also be referred to as “RRC measurements.” Similarly, during the LTM execution phase, UE230 can provide one or more measurements to the serving DU214 via Layer 1 (L1). In this regard, measurements reported via L1 may also be referred to as “L1 measurements.”

[0066] Upon receiving measurements from UE230, base station 210 (e.g., CU212) can prepare one or more candidate cells from among the neighboring cells based on the measurements provided by UE230. Accordingly, base station 210 can provide the configuration of the candidate cells to UE230 via RRC signaling. For example, CU212 can obtain information on cells 224-228 from DU214 and DU216 and then select cells 226-228 as candidate cells. Accordingly, CU212 can provide the configuration of cells 226-228 to UE230 via at least one RRC reconfiguration message.

[0067] Subsequently, the UE230 can perform one or more L1 measurements on one or more candidate cells and / or serving cells sequentially (or periodically) and transmit the results of one or more L1 measurements (e.g., in the form of an L1 measurement report) to the serving DU214. Based on the one or more L1 measurements provided by the UE230, the serving DU214 can determine whether an LTM cell switchover is necessary or expected (e.g., whether any of the candidate cells meet the criteria for an LTM cell switchover and can be selected as an LTM target cell).

[0068] For example, the serving DU214 can determine whether one or more criteria (which may be referred to herein as “LTM cell switching criteria”) are met based on one or more parameters in the L1 measurement (e.g., RSRP, SINR, etc.), and based on the determination that one or more LTM cell switching criteria are met, it can determine whether an LTM cell switching is required or expected. According to embodiments, based on the determination that an LTM cell switching is not currently required or expected, the serving DU214 can predict whether an LTM cell switching is expected in one or more next cell DTX / DRX cycles (exemplary embodiments associated therewith are further described below with reference to Figures 8-10).

[0069] In this regard, when Serving DU214 determines that an LTM cell switchover is required or expected, Serving DU214 can select one of the candidate cells as the target cell and trigger the LTM cell switchover procedure by generating and providing an LTM cell switchover command to UE230. The LTM cell switchover command may include target cell identification information and at least some LTM parameter configurations for the target cell. For example, in the example in Figure 2, Serving DU214 can select cell 228 as the target cell and provide the LTM configuration of cell 228 to UE230 (within the LTM cell switchover command). According to the embodiment, Serving DU214 can provide the LTM cell switchover command within MAC CE.

[0070] According to the embodiment, the serving DU214 can determine a primary target cell and provide an LTM cell switching command to the UE230 to perform a primary LTM cell switching (e.g., a first cell switching). In addition, the DU214 can determine at least one secondary target cell and provide the UE230 with an LTM fallback configuration to enable LTM failure recovery, so that the UE230 can autonomously perform a secondary LTM cell switching (e.g., a second cell switching, a third cell switching, etc.) without requiring further LTM cell switching commands from the serving DU214 when the primary LTM cell switching fails. The LTM fallback configuration may include a configuration of at least one secondary target cell (e.g., an LTM configuration, etc.). For example, in the example in Figure 2, the DU214 can select cell 228 as the primary target cell and cell 226 as the secondary target cell. Accordingly, DU214 can provide UE230 with an LTM fallback configuration (including the configuration of cell 226), so that UE230 can autonomously perform a secondary LTM cell switch from cell 222 to cell 226 if the LTM cell switch from cell 222 to cell 228 fails. The LTM fallback configuration may be provided in an LTM cell switch command along with the LTM configuration of the primary target cell, or it may be provided to UE230 within a single MAC CE. Further description of relevant exemplary embodiments is provided below with reference to Figure 11.

[0071] Upon receiving an LTM cell switch command, the UE230 can perform an LTM cell switch from the serving cell to the target cell based on the LTM cell switch command. For example, the UE230 may be disconnected from the serving cell (e.g., cell 222) and apply the LTM configuration to the target cell (e.g., cell 228). The UE230 can then connect to the target cell by performing a random access procedure (e.g., a Random Access Channel (RACH) procedure) if the UE230 has not previously obtained the timing advance (TA) of the target cell. On the other hand, if the UE230 has obtained the TA of the target cell, the UE230 can adjust its uplink (UL) transmission according to the TA, thereby connecting to the target cell. Upon successful LTM cell switch, the UE230 can indicate the successful completion of the LTM cell switch toward the target cell and / or target DU. According to one embodiment, the UE230 can indicate the success of the LTM cell switchover by sending a UL data packet to the target cell and / or associated DU (which will function as the new serving cell if the LTM cell switchover is successful). In some implementations, based on the determination that the LTM cell switchover was successful, the UE230 can further provide the CU212 with an RRC reconfiguration confirmation message.

[0072] According to one embodiment, the serving DU 214 may be configured to add at least one active period to at least one cell DTX / DRX cycle associated with the serving cell 222. According to one embodiment, the serving DU 214 can add multiple active periods (e.g., within multiple cell DTX / DRX cycles). Specifically, the serving DU 214 can select an active period coefficient from a plurality of predetermined active period coefficients. The serving DU 214 can then add or introduce multiple active periods based on the selected active period coefficient. A description of the exemplary operation associated therewith is provided below with reference to Figures 6A to 7. According to one embodiment, the serving DU 214 can predict an LTM cell switchover in the next cell DTX / DRX cycle and add at least one active period to at least one cell DTX / DRX cycle associated with the predicted LTM cell switchover. A description of the exemplary operation associated therewith is provided below with reference to Figures 8 to 10.

[0073] The length of the additional active period may be appropriately configured or adjustable by the network operator as needed, without departing from the scope of this disclosure. For example, instead of adding an active period based on an active period coefficient or based on a predicted LTM cell switchover, the serving DU214 may also add more active periods and / or extend the additional active period so that the UE can monitor the PDCCH for a longer period.

[0074] Accordingly, the serving DU214 can provide the UE230 with information for at least one additional active period, so that the UE230 can monitor the PDCCH during at least one additional active period and receive LTM cell switching commands from it in a timely manner. The serving DU214 can then provide the UE230 with LTM cell switching commands (in MAC CE) during at least one additional active period.

[0075] According to embodiments in which UE230 includes a group of UEs, DU214 can provide a group MAC CE to the group of UEs. The group MAC CE may contain the same information (e.g., information such as at least one additional active period, LTM cell switching commands, and LTM fallback configurations), and the group MAC CE may be provided to the group of UEs in any appropriate order. For example, the group MAC CE may be broadcast on the PDCCH, and a group of UEs monitoring the PDCCH can use a common LTM-RNTI to retrieve the group MAC CE from it simultaneously or sequentially.

[0076] In consideration of the foregoing, exemplary embodiments of the present disclosure provide system architectures, mechanisms, procedures, etc., for facilitating cell DTX / DRX interaction with LTMs, thereby enabling proper execution of LTM cell switching when at least one UE is configured as an LTM and the serving cell is configured as a DTX / DRX. Specifically, exemplary embodiments of the present disclosure provide systems, methods, devices, etc., that enable a base station (e.g., a DU) to provide one or more UEs with LTM cell switching commands in a timely manner, so that one or more UEs can receive LTM cell switching commands from the DU in a timely manner and perform LTM cell switching thereon, even when the UEs are configured as an LTM and the serving cell is configured as a DTX / DRX.

[0077] Furthermore, a base station (e.g., DU) can provide an LTM fallback configuration to the UE, thereby ensuring that the UE can autonomously perform a secondary LTM cell switchover if the primary LTM cell switchover fails. Additionally, operations associated with the cell configuration may be performed at the CU, and the cell switchover may be performed autonomously at the DU without further interaction with higher layers. Finally, exemplary embodiments of this disclosure provide a system architecture and mechanism for facilitating cell DTX / DRX interactions with LTMs in a decomposed architecture.

[0078] Exemplary behavior to facilitate cell DTX / DRX interaction with LTM As described above, according to the embodiments, the distributed unit (DU) may be configured to add at least one active period to the cell DTX / DRX associated with the serving cell, so that the DU can provide timely LTM cell switching commands to at least one user equipment (UE), thereby facilitating cell DTX / DRX interaction with the LTM. A description of exemplary embodiments associated therewith is provided below with reference to Figures 3 to 5.

[0079] First, refer to Figure 3, which illustrates the operation on the DU side. Specifically, Figure 3 shows a flowchart of an exemplary method 300 for adding at least one active period and providing an LTM cell switching command, according to one or more embodiments. One or more operations of method 300 may be performed by a serving DU, or a component of the network node where the serving DU is deployed (e.g., a processor). According to embodiments, the DU may include a DU associated with a serving NG-RAN node (which may be referred to herein as a “serving NG-RAN node DU”).

[0080] Referring to Figure 3, in operation S310, the Serving DU may be configured to add at least one active period to at least one cell DTX / DRX cycle associated with the Serving Cell. The Serving Cell may be hosted or serviced by the Serving DU and may be communicably coupled to at least one UE. The added at least one active period may function as an additional and / or dedicated LTM cell switching command transmission window in the associated cell DTX / DRX cycle, during which the Serving DU may send a MAC CE (containing the LTM cell switching command) to the UE or a group MAC CE to a group of UEs. Thus, the at least one active period may also be referred to herein as the “LTM-specific active period”.

[0081] According to the embodiment, the serving DU may be configured to add multiple active periods to multiple cell DTX / DRX cycles. Specifically, the serving DU receives at least one L1 measurement from at least one UE and can then predict the timing of LTM cell switching during an inactive period (based on at least one L1 measurement). Accordingly, the serving DU can select an active period coefficient corresponding to the predicted timing (from a plurality of predetermined active period coefficients based on at least one L1 measurement). The serving DU can then add or introduce multiple active periods based on the selected active period coefficient. A description of exemplary embodiments associated therewith is provided below with reference to Figures 6A to 7.

[0082] According to the embodiment, the serving DU can predict the timing of the next LTM cell switchover in the next cell DTX / DRX cycle and can add at least one active period to at least one cell DTX / DRX cycle associated with the predicted LTM cell switchover. Specifically, the serving DU may be configured to predict the timing when the LTM cell switchover is expected and then add at least one active period to adapt to the timing when the LTM cell switchover is expected and / or to adapt to the timing when the cell switchover command is expected to be sent to at least one UE. A description of exemplary embodiments associated therewith is provided below with reference to Figures 8 to 10.

[0083] If at least one active period is added, method 300 can proceed to operation S320, where the serving DU may be configured to provide information of at least one added active period to at least one UE. The at least one UE may be hosted or serviced by a serving cell and may be configured as an LTM. The information of at least one added active period may include the start and end times of the added active period. The at least one UE may include UEs with multiple LTM configurations.

[0084] In an embodiment in which the Serving DU adds at least one active period based on an active period coefficient, the information for the at least one added active period may further include information on the active period coefficient. In an embodiment in which the Serving DU adds at least one active period based on a predicted LTM cell switchover, the information for the at least one added active period may further include information on the predicted LTM cell switchover, such as the timing at which the LTM cell switchover is expected and the expected transmission time of the LTM cell switchover command.

[0085] According to the embodiment, the serving DU may be configured to provide information on at least one additional active period via MAC CE (a description of an exemplary embodiment associated therewith is provided below with reference to Figure 8) and / or via RRC signaling (a description of an exemplary embodiment associated therewith is provided below with reference to Figures 6A and 9).

[0086] By providing information for at least one additional active period, method 300 can proceed to operation S330, where the serving DU may be configured to provide an LTM cell switch command to the UE. Specifically, the serving DU may generate a MAC CE containing an LTM cell switch command during at least one additional active period and provide the MAC CE to the UE. The LTM cell switch command may enable or instruct the UE to perform an LTM cell switch from the serving cell to the target cell. According to embodiments, the LTM cell switch command may include target cell identification information and indicate the LTM configuration of the target cell. In some implementations, the MAC CE and / or LTM cell switch command may further include an LTM fallback configuration. The LTM fallback configuration may include the LTM configuration of at least one secondary target cell used for LTM failure recovery. Furthermore, the serving DU may generate a MAC CE by generating a new MAC CE or by modifying an existing MAC CE (e.g., a MAC CE previously used to provide an LTM cell switch command in the past).

[0087] According to embodiments in which at least one UE includes multiple UEs, a serving DU can provide a group MAC CE to multiple UEs. The group MAC CE may contain the same information (e.g., information such as at least one additional active period, LTM cell switching commands, and LTM fallback configurations) and may be provided to multiple UEs in any appropriate order. For example, the group MAC CE may be broadcast on the PDCCH, and multiple UEs monitoring the PDCCH can obtain the group MAC CE from it simultaneously or sequentially. A typical LTM RNTI may be used to keep PDCCH monitoring limited to LTM-configured UEs.

[0088] Next, refer to Figure 4, which illustrates the operation on the UE side. Specifically, Figure 4 is a flowchart of an exemplary method 400 for receiving an LTM cell switching command and performing an LTM cell switching, according to one or more embodiments. One or more operations of method 400 may be performed by a user device (UE). The UE may consist of an LTM and may be connected to a serving cell associated with a serving DU.

[0089] Referring to Figure 4, in operation S410, the UE may be configured to receive information on at least one active period. Specifically, the UE may be configured to receive information from the Serving DU on at least one active period added by the Serving DU to at least one cell DTX / DRX cycle associated with the Serving cell. The at least one added active period may be an LTM-specific active period.

[0090] As described above with reference to operation S320, the information for at least one additional active period may include information for multiple active periods added by the Serving DU to multiple cell DTX / DRX cycles (based on the active period coefficient) or information for at least one active period added by the Serving DU to at least one associated cell DTX / DRX cycle (based on the predicted LTM cell switchover information). The information may include the start and end times of the additional active period, the predicted LTM cell switchover information (if any), the active period coefficient information (if any), and so on. Furthermore, the UE may be configured to receive the information in a MAC CE (different from the MAC CE containing the LTM cell switchover command) and / or in an RRC reconfiguration message (provided by a CU communicably coupled to the Serving DU).

[0091] Upon receiving information of at least one additional active period, method 400 may proceed to operation S420, where the UE may be configured to monitor the physical downlink control channel (PDCCH) during at least one additional active period. Specifically, the UE may monitor the PDCCH during the LTM cell switching command transmission window (defined at least by at least one additional active period), and then decode the PDCCH to obtain a MAC CE containing the LTM cell switching command. In this regard, if the DU adds multiple active periods (in operation S310), the UE may monitor the PDCCH during the multiple additional active periods. According to embodiments, the LTM cell switching command transmission window may be defined by both a normal active period and at least one additional active period. In this case, the UE may monitor the PDCCH during both the normal active period and at least one additional active period.

[0092] In some embodiments, the LTM cell switching command (included in the MAC CE) may include target cell identification information and instructions for the LTM configuration of the target cell to which the UE should switch. In some implementations, the MAC CE may further include an LTM fallback configuration. The LTM fallback configuration may include the LTM configuration of at least one secondary target cell.

[0093] Upon receiving an LTM cell switching command, method 400 can proceed to operation S430, where the UE may be configured to perform an LTM cell switching from the serving cell to the target cell. For example, the UE may be disconnected from the serving cell and apply the LTM configuration of the target cell (included in the LTM cell switching command). The UE can then connect to the target cell by performing a random access procedure (e.g., a random access channel (RACH) procedure) if the UE has not yet obtained the timing advance (TA) of the target cell. On the other hand, if the UE has obtained the TA of the target cell, the UE can adjust its uplink (UL) transmission according to the TA, thereby connecting to the target cell.

[0094] According to the embodiment, method 400 may further include one or more actions when performing an LTM cell switchover in operation S430. Specifically, the UE may determine whether the LTM cell switchover was successful and then perform one or more actions based on that determination.

[0095] For example, based on the determination that the LTM cell switchover was successful, the UE may indicate the success of the LTM cell switchover completion to the target cell (now operating as the new serving cell) and associated DU. According to the embodiment, the UE may indicate the success of the LTM cell switchover by sending a UL data packet or message to the target cell and / or target DU. Upon receiving the instruction for a successful LTM cell switchover, the serving DU may deactivate or cancel the added active period. In some implementations, based on the determination that the LTM cell switchover was successful, the UE may provide an RRC reconfiguration confirmation message to the central unit (CU) associated with the serving DU.

[0096] In addition, based on the determination that an LTM cell switchover has failed, the UE may be configured to perform a secondary LTM cell switchover. Specifically, the UE may receive an LTM fallback configuration from the serving DU and, based on the LTM fallback configuration, autonomously or automatically perform a secondary LTM cell switchover from the serving cell to the secondary cell without requiring any further LTM cell switchover commands. A description of exemplary embodiments is provided below with reference to Figure 11.

[0097] In some implementations, the operations of Method 300 and Method 400 may be performed sequentially. For example, Figure 5 shows a flow sequence of an exemplary embodiment in which the operations of Method 300 and Method 400 are performed sequentially, according to one or more embodiments. The flow sequence may include at least one DU and at least one UE. For illustrative purposes, the exemplary embodiment in Figure 5 is shown to include the serving DU 214 and UE 230 described above with reference to Figure 2.

[0098] Referring to Figure 5, the serving DU214 can (in step 1) initially add at least one active period to at least one cell DTX / DRX cycle associated with the serving cell. The serving DU214 can then (in step 2) provide the UE230 with information about the at least one added active period. Upon receiving the information about the at least one added active period, the UE230 can (in step 3) monitor the PDCCH during the at least one added active period. Accordingly, the serving DU214 can (in step 4) provide the UE230 with a MAC CE containing an LTM cell switching command during the at least one added active period. Since the UE230 has been monitoring the PDCCH during the at least one added active period, the UE230 can receive the MAC CE from the DU214 in a timely manner. The UE230 can then (in step 5) perform the LTM cell switching according to the LTM cell switching command contained in the MAC CE. Steps 1, 2, and 4 in Figure 5 may be similar to operations S310, S320, and S330 of Method 300, respectively. Steps 3 and 5 in Figure 5 may be similar to operations S420 and S430 of Method 400.

[0099] To this end, exemplary embodiments of the present disclosure provide features and mechanisms for a base station (e.g., DU) to add at least one active period to at least one cell DTX / DRX cycle of a serving cell, thereby enabling the base station to introduce an additional or dedicated LTM cell switching command transmission window for providing an LTM cell switching command to the UE. Furthermore, exemplary embodiments of the present disclosure also provide features and mechanisms for the UE to receive information on at least one added active period of at least one cell DTX / DRX cycle and then monitor the PDCCH during at least one LTM cell switching command transmission window defined by the at least one added active period, thereby enabling the UE to receive an LTM cell switching command from the base station. Finally, the LTM cell switching command may be provided to the UE in a timely manner, thereby avoiding any delay in the LTM cell switching and mitigating the risk of RLF resulting from a delayed LTM cell switching.

[0100] Exemplary use case: Adding active periods based on an active period coefficient As described above, according to the embodiment, a distributed unit (DU) of a base station (e.g., gNB) may be configured to add multiple active periods within multiple DRX cycles associated with a serving cell, based on an active period coefficient. The DU may include a serving DU (e.g., a serving NG-RAN node DU), and the multiple added active periods may include multiple LTM-specific active periods.

[0101] According to one embodiment, the serving DU can initiate an operation to add multiple active periods when it determines that the serving cell is composed of cells DTX / DRX (for example, during the serving cell startup process).

[0102] As another example, information for adding multiple active periods may be provided to the serving cell in the initial stages (e.g., during the serving cell startup process), and the action to add multiple active periods may be initiated under specific conditions. For example, the action to add multiple active periods may be initiated or activated when the UE fails to receive an LTM cell switch command under a normal cell DTX / DRX configuration, or when the serving DU fails to deliver an LTM cell switch command under a normal cell DTX / DRX configuration.

[0103] According to one embodiment, a serving DU can select an active period coefficient and then add multiple active periods to multiple cell DTX / DRX cycles based on it. The serving DU can then provide information about the multiple added active periods (e.g., information about the active period coefficient) to a UE (or a group of UEs) via RRC signaling. A description of exemplary embodiments associated therewith is provided below with reference to Figures 6A to 7.

[0104] Figures 6A and 6B show flow sequences of exemplary use cases for facilitating cell DTX / DRX interaction with LTM by adding multiple active periods based on an active period coefficient, according to one or more embodiments. CU212, serving DU214, and UE230 in Figures 6A and 6B may be similar to those described above with reference to Figures 2 and / or 5. Furthermore, one or more operations in Figures 6A and 6B may include, or be part of, one or more operations described above with reference to Figures 3 and 4. For example, steps 1-3 and 4-6 in Figure 6A may be part of operations S310 and S320 in Figure 3, respectively; step 7 in Figure 6A may be similar to operation S420 in Figure 4; step 13 in Figure 6B may be similar to operation S330 in Figure 3; and step 14 in Figure 6B may be similar to operation S430 in Figure 4.

[0105] Referring to Figure 6A, in step 1, the UE230 can provide the serving DU214 with at least one L1 measurement. For example, the UE230 can provide at least one L1 measurement report that includes one or more parameters obtained via the L1 measurement, such as Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), and Signal-to-Noise and Interference Ratio (SINR). The L1 measurement may be associated with the serving cell and / or one or more candidate cells.

[0106] Upon receiving the L1 measurement, in step 2, the serving DU214 can select an active period coefficient based on the L1 measurement. According to the embodiment, the serving DU214 can predict the timing of an LTM cell switchover during an inactive period based on the L1 measurement. For example, the serving DU214 can predict that an LTM cell switchover is expected during the next inactive period (when the serving cell is in sleep mode). Exemplary operation for predicting an LTM cell switchover is described below with reference to Figure 8. Accordingly, the serving DU214 can select an active period coefficient from a plurality of predetermined active period coefficients based on the L1 measurement that corresponds to the predicted timing. For example, each of the predetermined active period coefficients may be the coefficient of each of the existing active periods, and the serving DU214 can select an active period coefficient that extends the active period to cover the timing of the expected LTM cell switchover.

[0107] According to the embodiment, the active period coefficient may have a value greater than 1. For example, suppose the existing / normal active period is 20 ms and the active period coefficient has a value of "1.5". In this case, the multiple additional active periods would be 30 ms (i.e., 1.5 * 20 ms). Similarly, each of the predetermined active period coefficients may be the coefficient of each of the existing active periods. For example, the first predetermined active period coefficient may be the coefficient of the existing active period "1.5", the second predetermined active period coefficient may be the coefficient of the existing active period "2.0", and so on.

[0108] In some implementations, the active period coefficient (and a number of predetermined active period coefficients) may have a value of 1 or less (for example, when Serving DU214 simply wants to add an active period that is the same length as the existing / normal active period, or when Serving DU214 determines that an LTM cell switchover is expected during the inactive period and the time required to provide the LTM cell switchover command is shorter than the length of the existing / normal active period).

[0109] Continuing to refer to Figure 6A, once the active period coefficient is selected, in step 3, the serving DU214 can add multiple active periods to multiple cell DTX / DRX cycles of the serving cell. For example, the serving DU214 can determine, based on the active period coefficient, which cell DTX / DRX cycles should be modified and how the active periods should be added to the cell DTX / DRX cycles. As an example, the serving DU214 can determine or calculate the start and end times of the additional active periods based on the active period coefficient, and then add the active periods to the relevant cell DTX / DRX cycles. According to the embodiment, the serving DU214 can add multiple active periods to all available cell DTX / DRX cycles. Alternatively, the serving DU214 can add active periods to a portion of the cell DTX / DRX cycles. In this way, the serving DU214 can introduce additional or dedicated LTM cell switching command transmission windows to the cell DTX / DRX cycles, thereby ensuring that LTM cell switching commands can be provided to the UE230 in a timely manner when needed.

[0110] Subsequently, in step 4, the serving DU 214 can provide the CU 212 with information about the added active period via the F1 interface. For example, in the exemplary embodiment of Figure 6A, the added active period information may include information about the active period coefficient and information about the Radio Network Temporary Identifier (RNTI). The LTM RNTI may be generated by the serving DU 214 when the serving DU 214 determines that the UE 230 is configured as an LTM (for example, when the UE 230 is first connected to the serving cell). According to embodiments in which the UE 230 includes a group of UEs, the serving DU 214 can generate an LTM group RNTI applicable to the group of UEs. According to embodiments, the LTM RNTI may be specific to the UE 230 and / or specific to at least one UE configured as an LTM (e.g., another UE connected to the same serving cell serviced or hosted by the serving DU 214). While it is stated above that the serving DU214 provides the active period coefficient along with the LTM RNTI to the CU212, in some implementations, the serving DU214 may provide the LTM RNTI in a message separated from the message providing the active period coefficient without departing from the scope of this disclosure.

[0111] In step 5, UE230 may provide CU212 with at least one L3 measurement. According to the embodiment, the at least one L3 measurement may include at least one RRC measurement. Upon receiving the L3 measurement, in step 6, CU212 may provide UE230 with at least one RRC reconstruction message including additional active period information (e.g., active period coefficient), LTM RNTI information, and the LTM configuration of the candidate cell.

[0112] Specifically, CU212 can determine one or more candidate cells based on the L3 measurements provided by UE230, and then prepare the LTM configuration of the candidate cells. Accordingly, CU212 can generate at least one RRC reconstruction message containing information on the candidate cell's LTM configuration, as well as information on the LTM RNTI and active period (e.g., active period coefficient) that may be received from the serving DU214 in step 4. CU212 can then provide at least one RRC reconstruction message to UE230. In this regard, since the target cell can be selected from among the candidate cells, it can be understood that the LTM configuration of the candidate cell may also include the LTM configuration of the target cell. Furthermore, in some implementations, step 5 may be optional, and CU212 may provide UE230 with an RRC reconstruction message containing the LTM RNTI and expansion coefficient without the L3 measurements.

[0113] Upon receiving an RRC reconfiguration message, in step 7, the UE230 can monitor the PDCCH according to the information about the added active period. Specifically, based on the active period coefficient (included in the RRC reconfiguration message), the UE230 can determine which cell DTX / DRX cycles have had an added active period, what the start and end times of the added active period are, and monitor the PDCCH during the added active period. According to the embodiment, based on the information about the added active period, the UE230 can determine the information about the LTM cell switching command transmission window and monitor the PDCCH during the LTM cell switching command transmission window. In some implementations, the LTM cell switching command transmission window may be defined by both the normal / existing active period and the added active period. In this case, the UE230 can monitor the PDCCH during both the normal / existing active period and the added active period.

[0114] Without departing from the scope of this disclosure, UE230 may be provided in any suitable manner with any necessary information (e.g., information on the serving cell's cell DTX / DRX configuration or pattern) to determine the LTM cell switching command transmission window based on the active period coefficient (for example, UE230 may be provided with necessary information when UE230 is first connected to the serving cell).

[0115] Considering the above, the UE230 can monitor the PDCCH in addition to or instead of the normal / existing active period, thereby ensuring that LTM cell switching commands can be received in a timely manner when needed.

[0116] In embodiments where UE230 is configured with C-DRX, UE230 can adjust the relevant DRX cycle according to information about the active periods added to the serving cell's cell DTX / DRX cycle. For example, UE230 can determine whether the on-periods within the relevant DRX cycle are at least partially aligned with the normal and added active periods of the cell DTX / DRX cycle. Accordingly, based on the determination that the on-periods within the relevant DRX cycle are not aligned with the normal and / or added active periods of the cell DTX / DRX cycle, UE230 can adjust the relevant DRX cycle (e.g., by adding / extending on-periods, offsetting on-periods, etc.) so that the on-periods within it are at least partially aligned with the normal and / or added active periods of the cell DTX / DRX cycle. In this way, UE230 can ensure that PDCCH monitoring can be performed when UE230 is configured with C-DRX, thereby ensuring that LTM cell switching commands can be received in a timely manner when needed.

[0117] When monitoring PDCCH, the UE230 can perform at least one L1 measurement continuously (or periodically) for the serving cell and / or candidate cell. Referring now to Figure 6B, in step 8, the UE230 can provide the serving DU214 with at least one L1 measurement (e.g., periodically, continuously, etc.) (e.g., in one or more L1 measurement reports).

[0118] Upon receiving L1 measurements from UE230, the serving DU214 can determine whether an LTM cell switchover is required. For example, the serving DU214 can determine whether one or more LTM cell switchover criteria are met or satisfied based on one or more parameters included in the L1 measurements. According to one embodiment, the serving DU214 can compare one or more parameters in the L1 measurements (e.g., RSRP) with one or more predetermined thresholds to determine whether an LTM cell switchover is expected or required.

[0119] Accordingly, based on the determination that an LTM cell switchover is expected or required, in step 9, the serving DU214 may generate Downlink Control Information (DCI) that includes information about the LTM cell switchover command. For example, the DCI may include information about the expected transmission time of the MAC CE, or information about when a cell switchover command (including the LTM cell switchover command) needs to be sent to the UE230 or is expected to be sent.

[0120] Once the DCI is generated, in step 10, the serving DU214 can scramble the DCI. According to one embodiment, the serving DU214 can scramble the DCI based on the LTM RNTI (for example, the one generated by the serving DU214 in step 4). In some implementations, the serving DU214 can scramble the DCI based on the LTM RNTI in a similar manner to the procedure for scrambling the DCI format 2_6 based on the PS-RNTI, as described in one or more 3GPP technical specifications. According to an embodiment in which the UE230 includes a group UE, the serving DU214 can scramble the DCI based on the LTM group RNTI.

[0121] Accordingly, in step 11, the serving DU 214 can provide the scrambled DCI to the UE 230. For example, the serving DU 214 can map the scrambled DCI to a PDCCH, so that the UE 230 can obtain the scrambled DCI by monitoring and decoding the PDCCH. Then, in step 12, the UE 230 can decode the PDCCH to obtain the scrambled DCI and then descramble the DCI based on the LTM RNTI (received by the UE 230 in step 6). In this way, the UE 230 can obtain information on LTM cell switching commands (e.g., expected transmission time of MAC CE including LTM cell switching) and monitor a specific active period to ensure that LTM cell switching commands can be received in a timely manner.

[0122] In step 13, the serving DU214 can generate a MAC CE that includes an LTM cell switching command and provide the MAC CE to the UE230. The LTM cell switching command may include information about the target cell (e.g., the cell ID of the target cell, LTM configuration, etc.). According to the embodiment, the MAC CE may further include an LTM fallback configuration. The LTM fallback configuration may include information about one or more secondary target cells that satisfy one or more cell switching criteria (e.g., the cell ID of one or more secondary target cells, LTM configuration, etc.). According to the embodiment in which the UE230 includes a group of UEs, the serving DU214 can generate a group MAC CE and provide the group MAC CE to the group of UEs.

[0123] Upon receiving the MAC CE from the serving DU214, in step 14, the UE230 can perform an LTM cell switch from the serving cell to the target cell based on the LTM cell switch command (included in the MAC CE). This step may be similar to operation S430 in Figure 4 and step 5 in Figure 5. Therefore, for brevity, redundant explanations associated with them may be omitted below.

[0124] According to the embodiment, when an LTM cell switchover is performed in step 14, the UE230 can determine whether the LTM cell switchover was successful and can perform one or more actions based on that determination.

[0125] For example, based on the determination that the LTM cell switchover was successful, the UE230 may send a UL data packet or message to the new serving cell (i.e., the previous target cell) and / or associated DU, thereby indicating the success of the LTM cell switchover. Accordingly, the serving DU214 may cancel or deactivate the additional active period within the cell DTX / DRX cycle of the previous serving cell. In some implementations, based on the determination that the LTM cell switchover was successful, the UE230 may provide an RRC reconfiguration confirmation message to the central unit (CU).

[0126] As another example, based on a determination that an LTM cell switchover has failed, the UE230 may automatically or autonomously perform a secondary LTM cell switchover from the serving cell to the secondary target cell based on the LTM fallback configuration. A description of exemplary embodiments associated therewith is provided below with reference to Figure 11.

[0127] Next, referring to Figure 7, it shows a diagram of an exemplary cell DTX / DRX cycle for an exemplary use case associated with the flow sequences of Figures 6A and 6B, according to one or more embodiments. Specifically, Figure 7 shows a diagram of an exemplary cell DTX / DRX cycle associated with a serving cell, according to one or more embodiments, with multiple active periods added thereto based on at least one active period coefficient.

[0128] Referring to Figure 7, multiple active periods are added to multiple cell DTX / DRX cycles. Specifically, one active period is added to each of cell DTX / DRX cycles "A" and "B". In other words, by adding active periods to the relevant cell DTX / DRX cycles, the LTM cell switching transmission window can be effectively added or extended.

[0129] According to the embodiment, the configuration of the active period may be predefined or adjustable by the network operator. For example, the length of the active period may be defined or adjustable by the network operator by controlling the active period coefficient, the timing for adding the active period may be defined or adjustable by the network operator by controlling the timing for providing the active period coefficient, and so on.

[0130] According to the embodiment, during the LTM cell switch command transmission window (defined by the normal active period and / or additional active periods), the UE can monitor the PDCCH to obtain LTM cell switch commands and then perform the LTM cell switch. In some embodiments, the additional active period may be dedicated to or specific to LTM-related operations. For example, during the additional active period, the UE may only monitor the PDCCH to obtain LTM cell switch commands and / or perform the LTM cell switch, and the serving DU may only send MAC CEs, etc., containing LTM cell switch commands without performing any other non-LTM-related operations.

[0131] In consideration of the foregoing, exemplary embodiments of the present disclosure provide features and mechanisms for effectively facilitating cell DTX / DRX interaction with LTM, thereby ensuring proper execution of LTM with respect to serving cells composed of cell DTX / DRX.

[0132] Specifically, exemplary embodiments of the present disclosure enable a base station (e.g., DU) to add multiple active periods within multiple cell DTX / DRX cycles associated with a serving cell, thereby introducing an additional or dedicated LTM cell switching command transmission window for providing LTM cell switching commands to the UE, ensuring that LTM cell switching commands can be provided to the UE in a timely manner. Furthermore, exemplary embodiments of the present disclosure enable the UE to receive information on the added active periods, thereby enabling the UE to monitor the PDCCH during at least the LTM cell switching command transmission window defined by the added active periods and receive LTM cell switching commands therefrom. Finally, the embodiments described above provide means (instead of or in addition to those described below with reference to Figures 8-10) to ensure that LTM cell switching commands can be provided to the UE in a timely manner, thereby avoiding any delay in LTM cell switching and mitigating the risk of RLF resulting from delayed LTM cell switching.

[0133] Exemplary use case: Predicting LTM cell switchover and adding specific active periods. As described above, according to the embodiment, a distributed unit (DU) of a base station (e.g., gNB) may be configured to anticipate LTM cell switching and add at least one active period within at least one cell DTX / DRX cycle associated with a serving cell. The DU may include a serving DU (e.g., a serving NG-RAN node DU), and the at least one added active period may include an LTM-specific active period.

[0134] According to the embodiment, the serving DU can predict when an LTM cell switchover is expected or required, and can add at least one associated active period to adapt to the expected timing of the LTM cell switchover and / or the timing when a cell switchover command is required or expected to be sent or delivered to the relevant UE.

[0135] By adding an active period, the Serving DU can provide information for the added active period to the UE. According to the embodiment, the Serving DU can provide information to the UE using a Downlink (DL) MAC CE. As an addition or alternative, the Serving DU can provide information to the UE using RRC signaling. A description of an exemplary embodiment in which the Serving DU provides information to the UE via MAC CE is provided below with reference to Figure 8, and a description of an exemplary embodiment in which the Serving DU provides information to the UE via RRC signaling is provided below with reference to Figure 9. According to the embodiment, providing information via MAC CE may be simpler and faster with minimal overhead compared to providing information via RRC signaling.

[0136] Figure 8 shows a flow sequence of an exemplary use case for facilitating cell DTX / DRX interaction with LTM by adding at least one active period based on a predicted LTM cell switchover, and providing information on at least one additional active period via MAC CE, according to one or more embodiments. The flow sequence may include at least one DU and at least one UE. For illustrative purposes, the exemplary embodiment in Figure 8 is shown to include the serving DU 214 and UE 230 described above with reference to Figure 2. Furthermore, one or more operations in Figure 8 may include, or be part of, one or more operations described above with reference to Figures 3 to 6B. For example, step 1 in Figure 8 may be part of operation S310 in Figure 3, or similar to step 1 in Figure 6A, steps 5 to 7 in Figure 8 may be similar to steps 3 to 5 in Figure 5, and so on.

[0137] Referring to Figure 8, in step 1, UE230 can provide at least one L1 measurement to the serving DU214. This step may be similar to step 1 in Figure 6A. Therefore, for the sake of brevity, redundant explanations associated with them may be omitted below.

[0138] In step 2, the serving DU214 can predict the LTM cell switchover. Specifically, upon receiving the L1 measurement from the UE230, the serving DU214 can determine whether an LTM cell switchover is immediately required or expected (for example, in the current cell DTX / DRX cycle). Based on the determination that an LTM cell switchover is not immediately required or expected, the DU214 can determine whether an LTM cell switchover is expected or required after a certain period (for example, whether an LTM cell switchover is expected in the next cell DTX / DRX cycle, or after two cell DTX / DRX cycles).

[0139] According to the embodiment, the serving DU 214 can compare the RSRP value associated with the serving cell with a predetermined threshold, thereby determining whether an LTM cell switchover is required or expected. For example, based on the determination that the RSRP value is below the predetermined threshold, the serving DU 214 can determine that an LTM cell switchover is immediately required or expected. Furthermore, based on the determination that the RSRP value is equal to the predetermined threshold, the serving DU 214 can determine that an LTM cell switchover is required or expected at the first predetermined timing within the next inactive period. On the other hand, based on the determination that the RSRP value is greater than the predetermined threshold, the serving DU 214 can determine that an LTM cell switchover is required or expected at a second predetermined timing within the next inactive period.

[0140] According to the embodiment, the serving DU 214 can compare the RSRP value associated with the serving cell with a plurality of predetermined thresholds to determine whether an LTM cell switchover is required or expected. For example, based on the determination that the RSRP value satisfies a condition associated with a first predetermined threshold (e.g., less than / greater than / equal to the first predetermined threshold), the serving DU 214 can determine that an LTM cell switchover is immediately required or expected. Similarly, based on the determination that the RSRP value satisfies a condition associated with a second predetermined threshold (e.g., less than / greater than / equal to the second predetermined threshold), the serving DU 214 can determine that an LTM cell switchover is required or expected at a first predetermined timing within the next inactive period, and based on the determination that the RSRP value satisfies a condition associated with a third predetermined threshold (e.g., less than / greater than / equal to the third predetermined threshold), the serving DU 214 can determine that an LTM cell switchover is required or expected at a second predetermined timing within the next inactive period.

[0141] The serving DU214 can similarly predict LTM cell switching based on any other appropriate parameters within the L1 measurement, such as SINR and RSRQ. Furthermore, without departing from the scope of this disclosure, the serving DU214 can predict LTM cell switching between multiple subsequent periods, compare the RSRP value associated with the serving cell to the RSRP value associated with a candidate cell, compare the RSRP value associated with a candidate cell to a predetermined threshold, and so on.

[0142] According to the embodiment, the serving DU214 can predict LTM cell switching based on at least one artificial intelligence (AI) / machine learning (ML) model. The AI / ML model may be trained by any suitable training method, such as supervised learning (where the AI / ML model is trained on input data and corresponding predetermined parameters), unsupervised learning (where the AI / ML model is trained without predetermined parameters), semi-supervised learning (where the AI / ML model is trained with a mixture of predetermined and unpredetermined data / parameters), or reinforcement learning (where the AI / ML model is trained on input data and feedback signals resulting from the model's output in the environment in which the model interacts).

[0143] According to the embodiment, the serving DU214 (or any other suitable component) can be used to train an AI / ML model with, for example, the trajectory of the UE230 (e.g., the path taken by the end user associated with the UE230), the L1 RSRP value when an LTM cell switchover occurred in the past, and the cell IDs of the serving and target cells included in the previous LTM cell switchover.

[0144] For this purpose, the Serving DU214 can predict LTM cell switchovers using a trained AI / ML model. For example, the Serving DU214 can input one or more parameters of an L1 measurement (e.g., RSRP, RSRQ, SINR, etc.) into an AI / ML model, which can automatically provide an output indicating whether an LTM cell switchover is expected and (if any) when it is expected to occur.

[0145] When an LTM cell switchover is predicted, in step 3, the serving DU214 may add at least one active period to at least one cell DTX / DRX cycle of the serving cell. Specifically, the serving DU214 may determine which cell DTX / DRX cycle is associated with the predicted LTM cell switchover and then add an active period to the relevant cell DTX / DRX cycle to adapt to the timing when the LTM cell switchover is expected and / or when the cell switchover command needs to be delivered or sent to the UE230. Accordingly, the serving DU214 may introduce or add at least one LTM cell switchover command transmission window to adapt to the timing when the LTM cell switchover is expected and / or when the cell switchover command needs to be sent or delivered to the UE230.

[0146] In some implementations, the serving DU214 can be adapted to the timing when an LTM cell switchover is expected and / or when a MAC CE (including the LTM cell switchover command) is required or expected to be sent or delivered to the UE230 (which may also be referred to herein as the “MAC CE arrival time” or “MAC CE expected transmission time”).

[0147] For example, Serving DU214 may predict that an LTM cell switchover is expected in the next "xms," and that the LTM cell switchover command needs to be delivered / sent to the UE by the "yms" preceding the "xms." Accordingly, Serving DU214 may add one or more active periods within the relevant cell DTX / DRX cycle to adapt to the expected timing of the LTM cell switchover and / or the expected transmission time of the MAC CE. According to the embodiment, one or more of the timings (e.g., "xms," "yms," etc.) may be predefined and / or configurable by the network operator (via the base station). Alternatively, one or more of the timings may be determined by Serving DU214 based on the predicted LTM cell switchover. For example, Serving DU214 may configure or adjust the length of an additional active period based on a determination such as whether the predicted LTM cell switchover requires a longer / shorter time than the usual / existing active period.

[0148] By adding at least one active period, in step 4, the serving DU 214 can provide the UE 230 with information for at least one added active period. Specifically, in the exemplary embodiment of Figure 8, the serving DU 214 can generate a first MAC CE that includes information for the added active period and information for the expected transmission time of a second MAC CE (including an LTM cell switching command). The serving DU 214 can then provide the first MAC CE to the UE 230. The first MAC CE may be different from the second MAC CE. Furthermore, the first MAC CE may be provided to the UE 230 during an active period prior to the added active period, and the second MAC CE may be provided to the UE 230 during the added active period. According to embodiments in which the UE 230 includes a group UE, the first MAC CE may be a first group MAC CE, and the second MAC CE may be a second group MAC CE.

[0149] Upon receiving the first MAC CE, in step 5, the UE230 can monitor the PDCCH during the added active period. Specifically, the UE230 can determine one or more LTM cell switching command transmission windows defined by the added active period, and then monitor the PDCCH during the LTM cell switching command transmission windows.

[0150] Subsequently, in step 6, the serving DU214 can generate a second MAC CE containing an LTM cell switching command. According to the embodiment, the second MAC CE may further include an LTM fallback configuration. Next, the serving DU214 can provide the second MAC CE to the UE230 during the added active period. Specifically, the serving DU214 can provide the second MAC CE to the UE230 via the PDCCH. Since the UE230 monitors the PDCCH during the added active period, the UE230 can decode the PDCCH during the added active period, thereby obtaining the second MAC CE from it in a timely manner.

[0151] Upon obtaining the second MAC CE, the UE230 can obtain an LTM cell switching command from it and perform an LTM cell switching from the serving cell to the target cell. The exemplary operation associated with it is described above with reference to operation S430 of Method 400 and may be similar to step 14 in Figure 6B. Therefore, for the sake of brevity, redundant explanations associated with them may be omitted below.

[0152] According to one embodiment, upon performing an LTM cell switchover, the UE230 determines whether the LTM cell switchover was successful and may perform one or more further actions based on that determination. Illustrative actions associated with these are described above with reference to Figure 6B.

[0153] Considering the above, the serving DU214 can add at least one active period based on the predicted LTM cell switchover and provide information associated with the added active period to the UE230 via MAC CE. Alternatively or additionally, the DU214 can provide information to the UE230 via RRC signaling.

[0154] Figure 9 shows a flow sequence of an exemplary use case for facilitating cell DTX / DRX interaction with LTM by adding at least one active period based on a predicted LTM cell switchover, and providing information of the at least one added active period via RRC signaling, according to one or more embodiments. The flow sequence may include at least one DU, at least one CU, and at least one UE. For illustrative purposes, the exemplary embodiment in Figure 8 is shown to include the serving DU 214, CU 212, and UE 230 described above with reference to Figure 2. Furthermore, one or more operations in Figure 9 may include, or be part of, one or more operations described above with reference to Figures 3 to 8. For example, steps 1, 2, and 3 in Figure 9 may be similar to steps 1, 2, and 3 in Figure 8, respectively; steps 6, 7, and 8 in Figure 9 may be similar to steps 3, 4, and 5 in Figure 5, respectively, and similar to steps 5, 6, and 7 in Figure 8, respectively, and so on.

[0155] Referring to Figure 9, in step 1, the UE230 can provide the serving DU214 with at least one L1 measurement. Accordingly, in step 2, the serving DU214 can predict the LTM cell switchover. Next, in step 3, the serving DU214 can add at least one active period to at least one cell DTX / DRX cycle associated with the serving cell. As described above, steps 1, 2, and 3 in Figure 9 may be similar to steps 1, 2, and 3 in Figure 8, respectively. Therefore, for brevity, redundant explanations associated with them may be omitted below.

[0156] Subsequently, in step 4, the serving DU214 can provide the CU212 with information about the added active period and the expected LTM cell switchover via the F1 interface. For example, the serving DU214 can initiate a UE context correction procedure toward the CU212 by sending an F1 Application Protocol (F1AP) UE context correction request message to the CU212. The F1AP UE context correction request message may include information about at least one added active period (e.g., start time, end time, etc.) and information about the expected transmission time of the MAC CE (including the LTM cell switchover command).

[0157] Upon receiving information about the predicted LTM cell switchover, in step 5, CU212 may generate and provide an RRC reconfiguration message to UE230. The RRC reconfiguration message may include information about the additional active period and information about the expected transmission time of MAC CE (including the LTM cell switchover command).

[0158] Upon receiving the RRC reconfiguration message, in step 6, the UE230 can monitor the PDCCH. Furthermore, in step 7, the serving DU214 can provide the UE230 with a MAC CE (including an LTM cell switching command). Then, in step 8, the UE230 can perform an LTM cell switch from the serving cell to the target cell in accordance with the LTM cell switching command. As described above, steps 6, 7, and 8 in Figure 9 may be similar to steps 3, 4, and 5 in Figure 5, respectively, and similar to steps 5, 6, and 7 in Figure 8, respectively. Therefore, for brevity, redundant explanations associated with them may be omitted below.

[0159] Referring to Figure 10, it illustrates exemplary use cases associated with the flow sequences of Figures 8 and 9, according to one or more embodiments. Specifically, Figure 10 shows an exemplary cell DTX / DRX cycle associated with a serving cell, according to one or more embodiments, with an active period added thereto based on predicted LTM cell switchover information.

[0160] Specifically, in the exemplary use case shown in Figure 10, the Serving DU can predict that an LTM cell switchover is expected during cell DTX / DRX cycle "B". For example, the Serving DU can predict that an LTM cell switchover is expected during the inactive period of cell DTX / DRX cycle "B" (within period T2-T3), and it is expected / needed that an LTM cell switchover command is sent / delivered to the UE by T1 so that the UE can acquire and execute the LTM cell switchover in a timely manner. The UE is required to monitor the PDCCH at least before period T1 in order to decode the PDCCH in a timely manner to acquire the MAC CE, and then acquire the LTM cell switchover command from the MAC CE. In this regard, the Serving DU can add an additional active period within cell DTX / DRX cycle "B" to adapt the timing of sending the MAC CE (i.e., the expected transmission time of the MAC CE) and the timing T1-T3, which is when the LTM cell switchover is expected.

[0161] By adding an active period, the Serving DU can provide information about the added active period to the UE during one or more of the active periods preceding the added active period. For example, the Serving DU can provide information to the UE during one or more of the active periods "X" and "Y". Furthermore, the Serving DU can provide information via one or more of the DL MAC CE and RRC signaling, respectively, as described above with reference to Figures 8 and 9. It is also conceivable that the Serving DU could provide information to the UE during other active periods preceding active period "X" without departing from the scope of this disclosure.

[0162] Upon receiving information about the additional active period, the UE can determine information for PDCCH monitoring based on the received information. For example, based on the information about the additional active period, the UE can determine at least one LTM cell switch command transmission window, such as when PDCCH should be monitored. For this purpose, the UE can monitor PDCCH during at least the LTM cell switch transmission window defined by the additional active period.

[0163] In some implementations, the LTM cell switchover transmission window may be defined by both the normal / existing active period and an additional active period. In that case, the UE can determine the information to monitor the PDCCH based on the additional active period information and the normal configuration / pattern of the cell DTX / DRX (which may be provided to the UE when the UE first connects to the serving cell).

[0164] According to an embodiment in which the UE is configured with C-DRX, the UE can modify the relevant DRX cycles based on information about the added active period (e.g., extending the relevant on period, offsetting the DRX cycles so that the existing on period aligns at least partially with the added active period) to ensure that the UE is in wake-up mode and can monitor PDCCH during the added active period.

[0165] Accordingly, during the added active period, the DU can generate a MAC CE (including an LTM cell switch command) and send it to the UE via the PDCCH. Since the UE monitors the PDCCH during the added active period, the UE can receive the MAC CE from it in a timely manner. The UE can then obtain the LTM cell switch command from the MAC CE and then perform the LTM cell switch based on it. According to embodiments in which the UE includes a group of UEs, the serving DU can similarly provide the UE with a group MAC CE (which may contain the same information as the MAC CE, such as information about at least one added active period).

[0166] In consideration of the foregoing, exemplary embodiments of the present disclosure provide features and mechanisms for a base station (e.g., DU) to predict an LTM cell switchover and add at least one active period to at least one cell DTX / DRX cycle based on the predicted LTM cell switchover information. Accordingly, the base station can provide the UE with information on the added active period in various ways (e.g., via MAC CE, via RRC signaling, etc.), and the UE may be configured to monitor the PDCCH during the added active period. Finally, an LTM cell switchover command may be provided to the UE in a timely manner, thereby avoiding any delay in the LTM cell switchover and mitigating the risk of RLF caused by a delayed LTM cell switchover.

[0167] Exemplary use case: Performing secondary LTM cell failover based on LTM fallback configuration As described above, according to the embodiment, the distributed unit (DU) can provide the UE with an LTM fallback configuration so that the UE can perform at least one secondary LTM cell switchover when a primary LTM cell switchover fails. The DU may include a serving DU (e.g., a serving NG-RAN node DU).

[0168] Specifically, upon receiving at least one L1 measurement from the UE, the Serving DU may select one candidate cell that satisfies one or more cell switching criteria as the primary target cell, and then select at least one of the remaining candidate cells that similarly satisfy one or more cell switching criteria as the secondary target cell. Accordingly, the Serving DU may provide the UE with an LTM fallback configuration that includes the configuration of the secondary target cell, so that the UE can autonomously perform a secondary LTM cell switch from the serving cell to the secondary target cell without requiring any additional cell switching commands from the Serving DU if the LTM cell switch to the primary target cell fails.

[0169] An LTM cell switch to a primary target cell may be referred to herein as a “primary LTM cell switch,” and an LTM cell switch to at least one secondary target cell may be referred to herein as a “secondary LTM cell switch.” In some implementations, at least one secondary target cell may include multiple secondary target cells, and a secondary LTM cell switch may include two or more secondary LTM cell switches. Thus, a primary LTM cell switch may also be referred to as a “first LTM cell switch,” and at least one secondary LTM cell switch may include a “second LTM cell switch,” a “third LTM cell switch,” and so on.

[0170] In some embodiments, the LTM fallback configuration may include the LTM configuration of the secondary target cell, and the Serving DU can provide the LTM fallback configuration to the UE in various ways. For example, the Serving DU may include the LTM fallback configuration within an LTM cell switch command, or within a MAC CE containing the LTM cell switch command. In this regard, in addition to the LTM configuration of the primary target cell and the LTM configuration of the secondary target cell, the MAC CE may further include one or more conditions for initiating or triggering at least one secondary LTM cell switch (e.g., one or more thresholds, parameters, etc., that can indicate to the UE when to perform a secondary LTM cell switch if the primary LTM cell switch is determined to have failed). The Serving DU can then provide the MAC CE to the UE, and as a result, the LTM fallback configuration may be provided to the UE before the primary LTM cell switch is performed. Exemplary operations for generating and providing a MAC CE containing an LTM cell switch command are described above with reference to Figures 3 to 10.

[0171] Taking the above into consideration, when generating a MAC CE to include an LTM cell switch command (instructing the UE to perform a primary LTM cell switch), the serving DU can include an LTM fallback configuration in the MAC CE, and as a result, the DU can provide the LTM fallback configuration to the UE when providing the LTM cell switch command.

[0172] Figure 11 shows a flow sequence of an exemplary use case for providing an LTM fallback configuration to a UE by one or more embodiments, and enabling the UE to perform at least one secondary LTM cell switchover. The flow sequence may include at least one DU and at least one UE. For illustrative purposes, the exemplary embodiment in Figure 11 is shown to include the serving DU 214 and UE 230 described above with reference to Figure 2. Furthermore, one or more operations in Figure 11 may include, or be part of, one or more operations described above with reference to Figures 3 to 10. For example, step 1 in Figure 11 may be similar to step 1 in Figures 6A, 8, and 9; step 4 in Figure 11 may be similar to step 5 in Figure 5, step 14 in Figure 6B, step 7 in Figure 8, and step 8 in Figure 9, respectively, and so on.

[0173] Referring to Figure 11, in step 1, UE230 can provide at least one L1 measurement to the serving DU214. As described above, step 1 in Figure 11 may be similar to step 1 in Figures 6A, 8, and 9. Therefore, for the sake of brevity, redundant explanations associated with them may be omitted below.

[0174] Upon receiving at least one L1 measurement, in step 2, the serving DU214 can determine a primary target cell and at least one secondary target cell based on the received L1 measurement. Specifically, upon receiving an L1 measurement from the UE230, the serving DU214 can determine from among several candidate cells whether any of the candidate cells meet one or more cell switching criteria. Information on candidate cells may be provided to the serving DU214 by the CU (e.g., CU212) hosting or servicing the serving DU214.

[0175] In this regard, if ServingDU214 determines that there is only one candidate cell that satisfies the cell switching criteria, ServingDU214 can select that candidate cell as the primary target cell. On the other hand, if ServingDU214 determines that there are multiple candidate cells that satisfy the cell switching criteria, ServingDU214 can select one of the multiple candidate cells as the primary target cell, and then select at least one of the remaining candidate cells (that satisfy the cell switching criteria) as the secondary target cell.

[0176] According to the embodiment, the serving DU214 can determine the primary and secondary target cells based on one or more conditions that are predefined or configurable by the network operator. A description of several exemplary use cases is provided below.

[0177] For example, based on the determination that there are multiple candidate cells that satisfy the cell switching criteria, Serving DU214 can select the candidate cell that satisfies the most cell switching criteria as the primary target cell and the candidate cell that satisfies the second most cell switching criteria as the secondary target cell. As an example, if we assume that the first candidate cell satisfies two cell switching criteria, the second candidate cell satisfies one cell switching criterion, and the third candidate cell does not satisfy any cell switching criteria, Serving DU214 can select the first candidate cell as the primary target cell and then the second candidate cell as the secondary target cell, without considering the third candidate cell (because it does not meet the minimum requirements for a target cell).

[0178] As another example, based on the determination that there are multiple candidate cells that satisfy the cell switching criteria, Serving DU214 may select the candidate cell that satisfies the highest priority cell switching criterion as the primary target cell, and then select the candidate cell that satisfies the second highest priority cell switching criterion as the secondary target cell. For example, assuming that the first candidate cell satisfies the highest priority cell switching criterion (e.g., a criterion associated with RSRP) and the second candidate cell satisfies the second highest priority cell switching criterion (e.g., a criterion associated with SINR), Serving DU214 may select the first candidate cell as the primary target cell, and then select the second candidate cell as the secondary target cell.

[0179] The examples described above are for illustrative purposes only and are not intended to limit the scope of this disclosure. Specifically, the serving DU214 may select primary and secondary target cells in any other suitable manner and / or based on any other suitable parameters / conditions without departing from the scope of this disclosure.

[0180] Once a primary target cell and at least one secondary target cell are selected, in step 3, the serving DU214 can provide the UE230 with an LTM cell switching command and an LTM fallback configuration (including information about the primary target cell). Specifically, the serving DU214 can generate an LTM cell switching command including the LTM configuration of the primary target cell, and then generate a MAC CE including the LTM cell switching command and the LTM fallback configuration. The serving DU214 can then provide the MAC CE to the UE230 (for example, via the PDCCH).

[0181] Upon receiving the MAC CE from the serving DU214, in step 4, the UE230 may perform a first LTM cell switch from the serving cell to the primary target cell (e.g., a primary LTM cell switch) based on the LTM cell switch command contained in the MAC CE. Step 4 in Figure 11 may be similar to operation S430 in Figure 4, step 5 in Figure 5, step 14 in Figure 6B, step 7 in Figure 8, and step 8 in Figure 9. Therefore, for brevity, redundant explanations associated with them may be omitted below.

[0182] Subsequently, in step 5, the UE230 can detect or determine whether the first LTM cell switchover was successful. For example, the UE230 may determine that the first LTM cell switchover (i.e., the primary LTM cell switchover) failed based on whether an RLF occurred, whether communication with the primary target cell was successful after the first LTM cell switchover was performed, etc.

[0183] Based on the detection that the first LTM cell switchover has failed, the UE230 can autonomously or automatically trigger a secondary LTM cell switchover without requiring any further cell switchover commands from the serving DU214. Specifically, in step 6, the UE230 can perform a second LTM cell switchover (e.g., a secondary LTM cell switchover) from the serving cell to the secondary target cell based on the LTM fallback configuration (received by the UE230 in step 3).

[0184] The exemplary use cases described above are for illustrative purposes only and should not be considered to limit the scope of this disclosure. Specifically, the serving DU214 may, without departing from the scope of this disclosure, select a secondary target cell and / or provide an LTM fallback configuration to the UE230 in any other suitable manner.

[0185] For example, instead of determining the secondary target cell in step 2, DU214 may determine the secondary target cell in step 5 when UE230 determines that the first LTM cell switchover has failed. As another example, serving DU214 may provide the LTM fallback configuration in a MAC CE different from the MAC CE containing the LTM cell switchover command. For example, DU may first provide the UE with a first MAC CE containing the LTM cell switchover command, and then later provide the UE with a second MAC CE containing the LTM fallback configuration.

[0186] Furthermore, one or more operations in Figure 11 may be repeated until the UE230 successfully switches from the serving cell to the target cell. For example, if the second LTM cell switch performed in step 6 fails, the UE230 may perform a third LTM cell switch from the serving cell to a third target cell in the same manner as described above. Furthermore, it will be understood that one or more operations in Figure 11 may be included in any of the exemplary embodiments described above with reference to Figures 2 to 10 and below with reference to Figures 12 to 14.

[0187] To this end, exemplary embodiments of the present disclosure provide features and mechanisms that enable a base station (e.g., a DU) to provide a fallback configuration to at least one UE, and that enable at least one UE to receive a fallback configuration from the base station. Accordingly, the UE can autonomously perform a secondary LTM cell switchover when a first primary LTM cell switchover fails. Ultimately, the risk of RLF resulting from LTM cell switchover failures can be reduced.

[0188] Example of a network node As described above, according to the embodiment, the central unit (CU) and distributed unit (DU) may be defined in software form and deployed on one or more network nodes (e.g., server nodes). A description of exemplary network nodes is provided below with reference to Figures 12 and 13.

[0189] Figure 12 shows a block diagram of exemplary components of network node 1200 according to one or more embodiments. Network node 1200 may include one or more servers on which the CU and / or DU of the exemplary embodiment may be implemented or deployed. According to the embodiment, network node 1200 may include edge servers or edge nodes. Additionally or alternatively, network node 1200 may include a central server or central node.

[0190] As shown in Figure 12, the network node 1200 may include at least one communication interface 1210, at least one storage 1220, and at least one processor 1230, but it will be understood that, without departing from the scope of this disclosure, the network node 1200 may include more or fewer components than those shown in Figure 12 and / or may be arranged in a manner different from that shown in Figure 12.

[0191] The communication interface 1210 may include at least one transceiver-like component (e.g., transceivers, separate receivers and transmitters, buses, etc.) that enables the components of the server node 1200 to communicate with each other via wired connections, wireless connections, or a combination of wired and wireless connections, and / or with one or more components outside the network node 1200.

[0192] According to the embodiment, the communication interface 1210 may include at least one transmitter, at least one receiver, and at least one antenna. The at least one transmitter may be configured to transmit data / information to one or more external nodes / devices using the antenna, and the at least one receiver may be configured to receive data / information from one or more external nodes / devices using the antenna. The at least one transmitter and the at least one receiver may be implemented together as a single transceiver module.

[0193] For example, the communication interface 1210 can connect the processor 1230 to the storage 1220, thereby enabling them to communicate with and interact with each other when performing one or more operations. As another example, the communication interface 1210 can connect the network node 1200 (or one or more components contained therein) to one or more network elements (e.g., network cells, UEs, etc.) to enable them to communicate with and interact with each other.

[0194] According to one or more embodiments, the communication interface 1210 may include one or more application programming interfaces (APIs) that enable the network node 1200 (or one or more components contained therein) to communicate with one or more software applications (e.g., software applications deployed within the UE, virtualized network functions, etc.).

[0195] According to one embodiment, the communication interface 1210 may include at least one input / output (I / O) interface, at least one network interface, and at least one storage interface.

[0196] According to the embodiment, the I / O interface may use communication protocols / methods such as, but are not limited to, audio, analog, digital, stereo, IEEE-1393, serial bus, Universal Serial Bus (USB), infrared, PS / 2, BNC, coaxial, component, composite, Digital Visual Interface (DVI), High Definition Multimedia Interface (HDMI®), radio frequency (RF) antenna, S-video, Video Graphics Array (VGA), IEEE 802.n / b / g / n / x, Bluetooth, and cellular (e.g., Code Division Multiple Access (CDMA), High Speed ​​Packet Access (HSPA+), Global System for Mobile Communications (GSM), Long-Term Evolution (LTE), WiMAX, etc.). Through the I / O interface, the network node 1200 can communicate with at least one input device (e.g., keyboard, mouse, touchscreen, sensor, microphone, scanner, camera, fingerprint scanner, etc.) and at least one output device (e.g., speaker, electronic screen, etc.).

[0197] Depending on the embodiment, the network interface may use, but is not limited to, direct connection, Ethernet (e.g., twisted-pair 10 / 100 / 1000-base T), Transmission Control Protocol / Internet Protocol (TCP / IP), Token Ring, IEEE 802.11a / b / g / n / x, and other connection protocols. The network node 1210 may be located on or communicate with the network via the network interface. An exemplary network description is provided below with reference to network 1430 in Figure 14.

[0198] According to the embodiment, the storage interface may use connection protocols including, but is not limited to, Serial Advanced Technology Attachment (SATA), Integrated Drive Electronics (IDE), IEEE-1393, Universal Serial Bus (USB), Fibre Channel, and Small Computer System Interface (SCSI). The storage interface can connect one or more components of the server node 1200 (e.g., processor 1220) to the storage 1220.

[0199] Continuing to refer to Figure 12, the storage 1220 may include one or more storage media suitable for storing data, information, and / or computer-executable instructions therein. According to embodiments, the storage 1220 may include at least one memory storage such as random access memory (RAM), read-only memory (ROM), and / or another type of dynamic or static storage device (e.g., flash memory, magnetic memory, and / or optical memory) for storing information and / or instructions for use by the processor 1230. Furthermore, the storage 1220 may further include drums, magnetic disk drives, magneto-optical drives, optical drives, redundant disk arrays (RAID), solid-state memory devices, solid-state drives, and the like. Further descriptions of memory are provided by referring to “Computer-Readable Media” as described herein.

[0200] As an addition or alternative, storage 1220 may include hard disks (e.g., magnetic disks, optical disks, magneto-optical disks, and / or solid-state disks), compact discs (CDs), digital multipurpose discs (DVDs), floppy disks, cartridges, magnetic tapes, and / or other types of non-temporary computer-readable media, along with their corresponding drives.

[0201] According to the embodiment, storage 1220 can function as a database that may be implemented as a fault-tolerant database, a relational database, a scalable database, and a secure database. In this case, storage 1220 may include, for example, Oracle or Sybase.

[0202] In some embodiments, the storage 1220 may be configured to store information such as raw data and metadata obtained from one or more nodes. Additionally or alternatively, the storage 1220 may be configured to store one or more pieces of information associated with one or more operations performed by the processor 1230. For example, the storage 1220 may store one or more results produced or generated by at least one processor 1230, information about network entities (network cells, UEs, etc.) involved in operations performed by the processor 1230, information about the history of operations performed by the processor 1230, and so on.

[0203] According to one embodiment, the storage 1220 can store software-based CUs and / or software-based DUs, as well as one or more pieces of information associated with them (e.g., computer-readable instructions for implementing the software-based CUs / software-based DUs, etc.). For example, the network node 1200 may include a cloud server, and the CUs and / or DUs may be defined in the form of cloud-native applications running on at least one OS within the cloud server.

[0204] Furthermore, storage 1220 may include memory or storage media that stores a collection of program or database components, such as a user interface, operating system, or web browser.

[0205] A user interface can facilitate the display, execution, interaction, manipulation, or operation of program components through text or graphic functions. For example, one or more user interfaces may provide computer interaction interface elements on a display system operably connected to the network node 1200, such as cursors, icons, checkboxes, menus, scrollers, windows, and widgets. Graphical user interfaces (GUIs) may be used, but are not limited to, Apple® Macintosh® operating systems such as Aqua®, IBM® OS / 2®, Microsoft® Windows® (e.g., Aero, Metro, etc.), and web interface libraries (e.g., ActiveX®, Java®, Javascript®, AJAX, HTML, Adobe® Flash®, etc.). In some implementations, storage 1220 may include multiple storage media, and storage 1220 may be configured to store copies or duplicates of at least a portion of the information on the multiple storage media to provide redundancy and to back up the information or related data.

[0206] The operating system can facilitate resource management and operation of network node 1200. Examples of operating systems include, but are not limited to, APPLE® MACINTOSH® OS X®, UNIX®, UNIX-based system distributions (e.g., BERKELEY SOFTWARE DISTRIBUTION® (BSD), FREEBSD®, NETBSD®, OPENBSD, etc.), LINUX® DISTRIBUTIONS (e.g., RED HAT®, UBUNTU®, KUBUNTU®, etc.), IBM® OS / 2®, MICROSOFT® WINDOWS® (XP®, VISTA® / 7 / 8, 10, 11, etc.), APPLE® IOS®, GOOGLE® ANDROID®, BLACKBERRY® OS, etc.

[0207] A web browser can be a hypertext browsing application such as MICROSOFT® INTERNET EXPLORER®, MICROSOFT® EDGE®, GOOGLE®, CHROME®, MOZILLA® FIREFOX®, or APPLE® SAFARI®. Secure web browsing may be provided using Secure Hypertext Transport Protocol (HTTPS), Secure Sockets Layer (SSL), Transport Layer Security (TLS), etc. Furthermore, web browsers may utilize features such as AJAX, DHTML, ADOBE® FLASH®, JAVASCRIPT®, JAVA®, and Application Programming Interfaces (APIs).

[0208] Continuing to refer to Figure 12, the processor 1230 may include at least one processor that can be programmed or configured to perform the functions or operations described herein. According to embodiments, the processor 1230 may be configured to receive one or more signals and / or instructions (for example, via a communication interface 1210, etc.) to trigger the performance of one or more operations.

[0209] Furthermore, the processor 1230 may be implemented in hardware, firmware, or a combination of hardware and software. For example, the processor 1230 may include at least one general-purpose or dedicated processing unit, such as a central processing unit (CPU), graphics processing unit (GPU), accelerator processing unit (APU), microprocessor, microcomputer, state machine, logic circuit, microcontroller, digital signal processor (DSP), field-programmable gate array (FPGA), application-specific integrated circuit (ASIC), integrated system (bus) controller, memory management control unit, floating-point unit, digital signal processing unit, and / or other types of processing or computing units.

[0210] According to one embodiment, the processor 1230 may be configured to execute software-based CUs and / or software-based DUs (or computer executable instructions for implementing CUs and / or DUs) stored in at least one storage medium or memory storage (e.g., storage 1220) to perform one or more activities or one or more operations as described herein.

[0211] In some embodiments, the network node 1200 may implement program components stored in the mail server. The mail server may be an internet mail server such as MICROSOFT® EXCHANGE®. The mail server may utilize functions such as Active Server Pages (ASP), ACTIVEX®, ANSI® C++ / C#, MICROSOFT®, .NET, CGI SCRIPTS, JAVA®, JAVASCRIPPT®, PERL®, PHP, PYTHON®, and WEBOBJECTS®. The mail server may utilize communication protocols such as Internet Message Access Protocol (IMAP), Messaging Application Programming Interface (MAPI), MICROSOFT® Exchange, Post Office Protocol (POP), and Simple Mail Transfer Protocol (SMTP). In some embodiments, the server node 1200 may implement program components stored in the mail client. A mail client can be an email viewing application such as APPLE® MAIL, MICROSOFT® ENTOURAGE®, MICROSOFT® OUTLOOK®, or MOZILLA® THUNDERBIRD®.

[0212] The exemplary embodiment in Figure 12 is described with reference to a network node for hosting or deploying a CU and / or DU, but it will be understood that the network node 1200 may also refer to a UE. Specifically, a UE may also include at least one communication interface, at least one storage, and at least one processor. In this regard, one or more operations associated with a UE described herein may be executed by at least one processor, for example, when executing instructions stored in at least one storage and / or received via a communication interface, without departing from the scope of this disclosure.

[0213] According to the embodiments, a CU and / or DU (or one or more operations associated therewith) may be implemented in the form of a containerized network function by one or more embodiments. The following provides a description of exemplary configurations for implementing a containerized function.

[0214] Figure 13 shows a block diagram of an exemplary configuration of network node 1300 in one or more embodiments. Network node 1300 may correspond to network node 1200 in Figure 12 and may be configured to implement one or more server platforms (a description of the exemplary embodiments associated therewith is provided below with reference to Figure 14).

[0215] According to the embodiment, a CU and / or DU (or one or more operations associated therewith) may be defined in software form, for example, via containerization (or any other suitable technique). Accordingly, a containerized CU and / or containerized DU may be deployed on the network node 1300 in the form of a container, and the functions / operations associated with the CU / DU may be executed via the execution or organization of the associated container.

[0216] As shown in Figure 13, network node 1300 may contain multiple containers 1311-1312 and 1321-1322. Containerized CUs and / or containerized DUs may be decomposed or distributed among multiple containers 1311-1312 and 1321-1322. For example, the functionality or operation of a DU may be distributed among containers 1311-1312, and the functionality or operation of a CU may be distributed among containers 1321-1322.

[0217] As an addition or alternative, containerized CUs and / or containerized DUs may be separated according to the type of operation. For example, functions or operations associated with UEs may be distributed between containers 1311 and 1312, and functions or operations associated with CUs and DUs may be distributed between containers 1321 and 1322. As another example, functions or operations associated with cell DTX / DRXs may be distributed between containers 1311 and 1312, and functions or operations associated with LTMs may be distributed between containers 1321 and 1322.

[0218] In one embodiment, the network node 1300 may include Kubernetes (K8s) nodes, and the containers (of the user plane) may be grouped or aggregated into their respective pods. In the exemplary embodiment shown in Figure 13, containers 1311-1312 are contained in the first pod 1310, and containers 1321-1322 are contained in the second pod 1320.

[0219] Multiple pods within network node 1300 can share the same resources (e.g., CPU, memory, etc.) provided by network node 1300. Resources allocated to facilitate and control cell DTX / DRX interactions with LTM may be managed by coordinating the associated pods and / or containers. For example, resources may be scaled up by increasing the number of containers and / or pods associated with them, or scaled down by decreasing the number of containers and / or pods associated with them, and so on.

[0220] It should be understood that the configuration shown in Figure 13 is simplified for illustrative purposes and does not limit the scope of this disclosure. Specifically, in practice, network node 1300 may include any suitable components for hosting and running multiple pods, the number of pods may be more than two, and the number of containers contained in each pod may be more than two. Furthermore, it should be understood that containerized CUs and / or containerized DUs (or their associated operations) may be hosted or deployed on multiple network nodes in a manner similar to that described above. Furthermore, it should be understood that multiple nodes may contain the same container (or pod) to provide network redundancy and thereby improve network availability.

[0221] For this purpose, exemplary embodiments of the present disclosure can provide one or more network nodes on which the CU and / or DU of the exemplary embodiments are implemented and deployed or may be implemented. Accordingly, one or more network nodes (or one or more processors associated therewith) may be configured to execute the CU and / or DU (or associated computer executable instructions) to perform one or more operations described herein, thereby facilitating cell DTX / DRX interaction with the LTM.

[0222] Furthermore, exemplary embodiments of this disclosure can leverage the benefits of containerization in facilitating cell DTX / DRX interactions with LTM. For example, since functionality may scale efficiently on demand and be easily replicated and organized across multiple nodes, implementing containerized CUs and / or containerized DUs (or associated behaviors) provides improved scalability, thereby enabling efficient resource utilization and seamless scaling.

[0223] Furthermore, containerized CUs and / or containerized DUs (or their associated behaviors) can be rapidly instantiated, migrated, and updated, enabling faster time to market for new services and features. Additionally, the functionality of CUs and / or DUs can be managed by coordinating the associated containers, thereby enabling independent development, testing, and deployment of the behavior.

[0224] In addition, implementing containerized CUs and / or containerized DUs (or their associated behaviors) can also improve resource utilization efficiency, enhance system security by leveraging container-specific security features, provide improved portability and interoperability, and enable seamless integration with different systems or platforms.

[0225] Example of an implementation environment As described above, according to the embodiment, the CU and / or DU (or associated operations) may be implemented on one or more network nodes, which may include a cloud server or cloud server cluster. A description of an exemplary cloud environment in which exemplary embodiments may be implemented is provided below with reference to Figure 14.

[0226] Figure 14 shows a diagram of an exemplary environment 1400 in which the systems and / or methods described herein may be implemented. As shown in Figure 14, the environment 1400 may include multiple nodes 1410, a server platform 1420, and a network 1430. The devices in environment 1400 may be interconnected via wired connections, wireless connections, or a combination of wired and wireless connections.

[0227] Multiple nodes 1410 may include one or more UEs and / or one or more network cells as described above. Therefore, for the sake of brevity, redundant explanations associated with them may be omitted below.

[0228] Network 1430 may include one or more wired and / or wireless networks. For example, Network 1430 may include cellular networks (e.g., 5G networks, 6G networks, Long-Term Evolution (LTE) networks, 3G networks, Code Division Multiple Access (CDMA) networks, etc.), public land mobile networks (PLMN), local area networks (LANs), wide area networks (WANs), metropolitan area networks (MANs), telephone networks (e.g., public switched telephone networks (PSTNs)), private networks, ad hoc networks, intranets, the Internet, fiber optic-based networks, and / or combinations of these or other types of networks. In addition or alternatively, Network 1430 may be implemented as one or more of various types of networks, such as intranets or local area networks (LANs), closed networks (CANs), etc. Furthermore, network 1430 can be either a dedicated network or a shared network, and they represent associations of different types of networks that communicate with each other using various protocols, such as Hypertext Transfer Protocol (HTTP), CAN protocol, Transmission Control Protocol / Internet Protocol (TCP / IP), Wireless Application Protocol (WAP), etc. Additionally, network 1430 may include various network devices, including routers, bridges, servers, computing devices, and storage devices.

[0229] The server platform 1420 may include one or more servers capable of receiving, generating, storing, processing, and / or providing information. According to the embodiment, the server platform 1420 may include one or more network nodes as described above with reference to Figures 12 and 13. In some implementations, the server platform 1420 may include a cloud server or a group of cloud servers.

[0230] In some implementations, the server platform 1420 may be designed to be modular, allowing specific software components to be swapped in or out depending on the specific needs. Therefore, the server platform 1420 may be easily and / or quickly reconfigured for different applications.

[0231] In some implementations, the server platform 1420 may be hosted within a cloud computing environment 1422, as illustrated. In particular, while the implementations described herein describe the server platform 1420 as being hosted within a cloud computing environment 1422, in some implementations, the platform 1420 may not be cloud-based (i.e., it may be implemented outside a cloud computing environment) or may be partially cloud-based.

[0232] The cloud computing environment 1422 includes an environment that hosts the server platform 1420. The cloud computing environment 1422 can provide compute, software, data access, storage, and services that do not require end-user knowledge of the physical location and configuration of the systems and / or devices that host the server platform 1420. As illustrated, the cloud computing environment 1422 may include a group of compute resources 1424 (collectively referred to as “Computer Resources 1424” and individually as “Computer Resources 1424”).

[0233] Computing resource 1424 may include one or more personal computers, clusters of computing devices, workstation computers, server devices, or other types of computing and / or communication devices. In some implementations, computing resource 1424 can host a server platform 1420. Cloud resources may include instances that compute and run on computing resource 1424, storage devices provided on computing resource 1424, and data transfer devices provided by computing resource 1424. In some implementations, computing resource 1324 can communicate with other computing resources 1424 via wired connections, wireless connections, or a combination of wired and wireless connections.

[0234] As further shown in Figure 14, the computing resource 1424 includes a group of cloud resources such as one or more applications ("APP") 1424-1, one or more virtual machines ("VM") 1424-2, virtualized storage ("VS") 1424-3, and one or more hypervisors ("HYP") 1424-4.

[0235] Application 1424-1 may include one or more software applications that can be provided to or accessed by node 1410. Application 1424-1 can eliminate the need to install and run software applications on node 1410. For example, application 1424-1 may include any other software that can be provided through the software associated with the server platform 1420 and / or the cloud computing environment 1422. In some implementations, one application 1424-1 can send and receive information to and from one or more other applications 1424-1 via a virtual machine 1424-2.

[0236] A virtual machine 1424-2 may include a software implementation of a machine (e.g., a computer) that runs programs like a physical machine. Depending on the intended use of the virtual machine 1424-2 and its degree of correspondence to any actual machine, the virtual machine 1424-2 may be either a system virtual machine or a process virtual machine. A system virtual machine can provide a complete system platform that supports the execution of a complete operating system ("OS"). An example of an OS is provided above with reference to Figure 12. A virtual machine can run a single program and can support a single process. In some implementations, the virtual machine 1424-2 can run on behalf of a user (e.g., a user associated with node 1410) and manage the foundation and / or configuration of a cloud computing environment 1422, such as data management, synchronization, or long-term data transfer.

[0237] Virtualized storage 1424-3 may include one or more storage systems and / or one or more devices that use virtualization techniques within the storage system or device of the computing resource 1424. In some implementations, within the context of a storage system, the types of virtualization may include block virtualization and file virtualization. Block virtualization may refer to the extraction (or isolation) of logical storage from physical storage so that the storage system can be accessed regardless of whether it is physical storage or heterogeneous. Isolation allows storage system administrators flexibility in how they manage storage for end users. File virtualization can eliminate dependencies between data accessed at the file level and where the files are physically stored. This may enable optimization of storage usage, server consolidation, and / or performance for non-disruptive file migration.

[0238] Hypervisor 1424-4 can provide hardware virtualization technology that enables multiple operating systems (e.g., "guest operating systems") to run simultaneously on a host computer such as computing resource 1424. Hypervisor 1424-4 can present a virtual operating platform to guest operating systems and manage the execution of guest operating systems. Multiple instances of various operating systems can share virtualized hardware resources.

[0239] The number and arrangement of devices and networks shown in Figure 14 are provided as an example. In practice, there may be more devices and / or networks, fewer devices and / or networks, different devices and / or networks, or devices and / or networks in different arrangements than those shown in Figure 14. Furthermore, two or more devices shown in Figure 14 may be implemented within a single device, or a single device shown in Figure 14 may be implemented as multiple distributed devices. Additionally or alternatively, a set of devices in environment 1400 (e.g., one or more devices) may perform one or more functions described as being performed by another set of devices in environment 1400.

[0240] In some embodiments, the CUs and / or DUs (or one or more operations associated therewith) described herein may be implemented or deployed within the server platform 1420 described above in the form of virtualized network functions (VNFs). In this regard, the terms “virtual,” “virtualized,” etc., described above are intended merely to specify the nature of machines (and associated elements and resources) provided in virtual or software form. In this regard, the terms “virtual machine,” “virtualized storage,” etc., described above should not be limited to any particular type of virtual machine or virtual element. Thus, it will be understood that the CUs and / or DUs (or one or more operations associated therewith) may be defined or presented in the form of containerized network functions, and that functionality may be provided in the form of containers. A description of exemplary implementation configurations for implementing the containerized function form (or associated operations) is provided above with reference to Figure 13.

[0241] To this end, by virtualizing and implementing CUs and / or DUs (or their associated operations) within the server platform 1420, resources (e.g., processing power, memory, storage, etc.) for facilitating cell DTX / DRX interactions with LTMs can be easily managed and dynamically scaled up or down on demand, thereby optimizing resource allocation and utilization. Furthermore, data and information associated with CUs and / or DUs can be easily cloned or backed up to provide redundancy, and access to data and information can be authorized and authenticated only to trusted entities.

[0242] Various embodiments The exemplary embodiments described above with reference to Figures 2 to 14 are merely examples of possible embodiments of the present disclosure and are not intended to limit or restrict the scope of the present disclosure.

[0243] Specifically, while the aforementioned disclosures provide examples and explanations, they are not intended to be exhaustive or to limit implementations to the very forms disclosed. Modifications and variations may be possible in light of the above disclosures or may be derived from the practice of the implementations.

[0244] Some embodiments may relate to devices (e.g., network nodes), systems, methods, and / or computer-readable media at any possible level of technically detailed integration. Furthermore, one or more of the above-described components may be stored in computer-readable media and implemented as instructions executable by at least one processor (and / or may include at least one processor). The computer-readable media may include computer-readable non-temporary storage media having computer-readable program instructions for causing the processor to perform an action.

[0245] Computer-readable storage media can be tangible devices capable of holding and storing instructions for use by instruction-executing devices. Computer-readable storage media may be, but are not limited to, electronic storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination thereof. A non-exhaustive list of more specific examples of computer-readable storage media includes, but are not limited to, portable computer diskettes, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), electrically erasable programmable read-only memory (EEPROM), static random access memory (SRAM), portable compact disk read-only memory (CD-ROM), digital multipurpose disks (DVDs), memory sticks, floppy disks, mechanically encoded devices such as punched cards or grooved raised structures on which instructions are recorded, and any suitable combination thereof. The computer-readable storage media used herein should not be construed as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses passing through optical fiber cables), or transient signals themselves, such as electrical signals transmitted through wires.

[0246] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device, or to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network may include copper transmission cables, optical transmission fibers, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. A network adapter card or network interface within each computing / processing device receives computer-readable program instructions from the network and transfers the computer-readable program instructions for storage on a computer-readable storage medium within each computing / processing device.

[0247] Computer-readable program code / instructions for performing an operation may be either source code or object code written in any combination of one or more programming languages, including assembler instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, configuration data for integrated circuits, or object-oriented programming languages ​​such as Smalltalk and C++, and procedural programming languages ​​such as the C programming language or similar programming languages.

[0248] Computer-readable program instructions can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or wide area network (WAN), or a connection may be made to an external computer (for example, via the Internet using an Internet service provider). In some embodiments, electronic circuits, including, for example, programmable logic circuits, field-programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), can execute computer-readable program instructions by utilizing state information of the computer-readable program instructions to personalize the electronic circuit in order to perform an aspect or operation.

[0249] These computer-readable program instructions may be provided to a general-purpose computer, a dedicated computer, or a processor of another programmable data processing device to generate a machine such that instructions executed via the processor of a computer or other programmable data processing device create means for performing a function / operation specified in one or more blocks of a flowchart and / or block diagram. These computer-readable program instructions may also be stored on a computer-readable storage medium on which the instructions are stored, which can be instructed to function in a particular manner to include a product containing instructions that perform a mode of function / operation specified in one or more blocks of a flowchart and / or block diagram.

[0250] Computer-readable program instructions may also be loaded into a computer, other programmable device, or other device to generate a computer implementation process by causing the computer, other programmable device, or other device to execute a series of operational steps so that the instructions executed on the computer, other programmable device, or other device perform a function / operation specified in one or more blocks of a flowchart and / or block diagram.

[0251] The flowcharts and block diagrams in the figures illustrate the architecture, functions, and operation of possible implementations of systems, methods, and computer-readable media in various embodiments. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of an instruction containing one or more executable instructions for implementing a specified logical function. Methods, computer systems, and computer-readable media may contain more blocks, fewer blocks, different blocks, or blocks in different arrangements than those depicted in the figures. In some alternative implementations, the functions shown in the blocks may be performed in an order other than that shown in the figures. For example, two blocks shown consecutively may actually be executed simultaneously or substantially simultaneously, or blocks may sometimes be executed in reverse order depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, as well as combinations of blocks in a block diagram and / or flowchart, may be implemented by a dedicated hardware-based system that performs a specified function or operation, or by executing a combination of dedicated hardware and computer instructions.

[0252] It will be apparent that the systems and / or methods described herein may be implemented in different forms of hardware, firmware, or combinations of hardware and software. The actual dedicated control hardware or software code used to implement these systems and / or methods is not limited to their implementation forms. Therefore, the operation and behavior of the systems and / or methods are described herein without reference to specific software code, and it is understood that software and hardware may be designed to implement the systems and / or methods based on the descriptions herein.

[0253] In consideration of the foregoing, various further aspects and features of the embodiments of this disclosure may be defined by the following items. Item [1]: A system comprising a Serving Distribution Unit (DU). The DU may be configured to add at least one Layer 1 (L1) / Layer 2 (L2) Trigger Mobility (LTM) specific active period to at least one cell discontinuous transmit (DTX) / discontinuous receive (DRX) cycle associated with a serving cell, to provide at least one user device (UE) with information about at least one additional active period, and to provide at least one UE with a Media Access Control (MAC) control element (CE) during at least one additional active period. The MAC CE transmitted during at least one additional active period may include a cell switching command instructing at least one UE to perform an LTM cell switch from the serving cell to a target cell. Item [2]: The system described in Item [1], which may be configured to add at least one active period by receiving an L1 measurement from at least one UE, predicting the timing of an LTM cell switchover during an inactive period based on the L1 measurement, selecting an active period coefficient from a plurality of predetermined active period coefficients based on the L1 measurement that corresponds to the predicted timing, each of which may be a coefficient of an existing active period, and adding a plurality of active periods to perform an LTM cell switchover based on the selected active period coefficient. Item [3]: The system described in Item [1], which may be configured to add at least one active period by having the serving DU receive an L1 measurement from at least one UE, predict the timing of an expected LTM cell switch based on the L1 measurement, and add an active period to at least one cell DTX / DRX cycle to adapt to the timing at which a cell switch command should be sent to at least one UE based on the predicted timing of the expected LTM cell switch. Item [4]: ​​A system as described in any one of items [1] to [3], wherein the target cell may be a primary target cell and the LTM cell switchover may be a first LTM cell switchover. The serving DU may be further configured to provide an LTM fallback configuration to at least one UE, the LTM fallback configuration may include a configuration for a secondary target cell different from the primary target cell. The LTM fallback configuration may be used by the UE to autonomously perform a second LTM cell switchover from the serving cell to a secondary target cell without a cell switchover command from the serving DU when a first LTM cell switchover fails and an LTM failure recovery is attempted. Item [5]: The system described in any one of items [1] to [4], wherein the Serving DU may be configured to provide information for at least one additional active period by providing information for at least one additional active period to multiple LTM-configured UEs connected to the Serving Cell, and the Serving DU may be configured to provide MAC CEs by sending MAC CEs to multiple LTM-configured UEs during at least one additional active period. Item [6]: The system described in any one of items [2], [4], and [5], wherein the system may further include a central unit (CU) communicably coupled to a serving DU and at least one UE. The serving DU may be configured to provide information for at least one additional active period by providing an active period factor to the CU via an F1 interface. The CU may be configured to generate a radio resource control (RRC) reconfiguration message containing the active period factor and target cell configuration, and to provide an RRC reconfiguration message to at least one UE. Item [7]: The system described in any one of items [3] to [5], wherein a MAC CE containing a cell switching command may be a second MAC CE, and the serving DU may be configured to provide information for at least one additional active period by generating a first MAC CE containing information about when an LTM cell switching is expected, and by providing the first MAC CE to at least one UE before at least one additional active period. The first MAC CE may be different from the second MAC CE. Item [8]: The system described in Item [6], wherein the Serving DU may be further configured to generate an LTM Radio Network Temporary Identifier (RNTI) unique to at least one UE configured with LTM, generate Downlink Control Information (DCI) containing MAC CE expected transmit time information, scramble the DCI based on the LTM RNTI, and provide the UE with the scrambled DCI prior to at least one additional active period. Item [9]: The system described in Item [8], in which the serving DU may be further configured to provide the LTM RNTI to the CU via the F1 interface, and the CU may be configured to generate an RRC reconfiguration message including the LTM RNTI, the active period coefficient, and the target cell configuration. Item

[10] : A system as described in any one of items [3]-[5] and [7], wherein the L1 measurement may include a reference signal received power (RSRP) value associated with the serving cell and at least one of the one or more candidate cells. The serving DU may be configured to predict the timing of an expected LTM cell switchover by comparing the RSRP value to a predetermined threshold, determining that an LTM cell switchover is expected at a first predetermined timing within the next inactive period based on the determination that the RSRP value is equal to the predetermined threshold, and determining that an LTM cell switchover is expected at a second predetermined timing within the next inactive period based on the determination that the RSRP value is greater than the predetermined threshold. Item

[11] : A system described in any one of items [3]-[5] and [7], in which the DU may be configured to predict when LTM cell switching is expected based on at least one artificial intelligence (AI) / machine learning (ML) model. Item

[12] : A method comprising adding at least one Layer 1 (L1) / Layer 2 (L2) trigger mobility (LTM) specific active period to at least one cell discontinuous transmit (DTX) / discontinuous receive (DRX) cycle associated with a serving cell; providing at least one user equipment (UE) with information about at least one added active period; and providing at least one UE with a media access control (MAC) control element (CE) during at least one added active period. The MAC CE transmitted during at least one added active period may include a cell switching command instructing at least one UE to perform an LTM cell switch from the serving cell to a target cell. Item

[13] : The method according to Item

[12] , wherein adding at least one active period may include receiving an L1 measurement from at least one UE, predicting the timing of an LTM cell switchover during an inactive period based on the L1 measurement, selecting an active period coefficient from a plurality of predetermined active period coefficients based on the L1 measurement that corresponds to the predicted timing, each of which is the coefficient of an existing active period, and adding a plurality of active periods to perform an LTM cell switchover based on the selected active period coefficient. Item

[14] : The method described in Item

[12] , which may include adding at least one active period to receive L1 measurements from at least one UE, predicting the timing of an expected LTM cell switch based on the L1 measurements, and adapting to the timing at which a cell switch command should be sent to at least one UE based on the predicted timing of the expected LTM cell switch. Item

[15] : The method of any one of items

[12] to

[14] , wherein the target cell may be a primary target cell and the LTM cell switchover may be a first LTM cell switchover. The method may further include providing an LTM fallback configuration to at least one UE, the LTM fallback configuration may include a configuration for a secondary target cell different from the primary target cell. The LTM fallback configuration may be used by at least one UE to perform a second LTM cell switchover from the serving cell to the secondary target cell autonomously without a cell switchover command from the serving DU when a first LTM cell switchover fails and an LTM failure recovery is attempted. Item

[16] : The method described in any one of items

[12] to

[15] , wherein providing information for at least one additional active period may include providing information for at least one additional active period to multiple LTM configured UEs connected to a serving cell, and providing a MAC CE may include sending a MAC CE to multiple LTM configured UEs during at least one additional active period. Item

[17] : The method of any one of items

[13] ,

[15] , and

[16] , wherein providing information on at least one additional active period may include generating a radio resource control (RRC) reconfiguration message containing an active period coefficient and a target cell configuration, and providing the RRC reconfiguration message to the UE. Item

[18] : The method described in any one of items

[14] to

[16] , wherein a MAC CE containing a cell switch command may be a second MAC CE, and providing information for at least one additional active period may include generating a first MAC CE containing information about when an LTM cell switch is expected, and providing the first MAC CE to at least one UE prior to at least one additional active period. The first MAC CE is distinct from the second MAC CE. Item

[19] : The method according to Item

[17] , wherein the method may further include generating an LTM radio network temporary identifier (RNTI) specific to or associated with at least one UE configured with LTM; generating downlink control information (DCI) including information on the expected transmission time of the MAC CE; scrambling the DCI based on the LTM RNTI; providing the scrambled DCI to the UE prior to at least one additional active period; and generating an RRC reconfiguration message including the LTM RNTI, an active period coefficient, and the configuration of the target cell. Item

[20] : A non-transient computer-readable recording medium that records instructions executable by at least one network node to cause at least one network node to perform a method including adding at least one Layer 1 (L1) / Layer 2 (L2) trigger mobility (LTM) specific active period to at least one cell discontinuous transmit (DTX) / discontinuous receive (DRX) cycle associated with a serving cell, providing at least one user equipment (UE) with information on at least one added active period, and providing at least one UE with a media access control (MAC) control element (CE) during at least one added active period. The MAC CE may include a cell switching command that instructs at least one UE to perform an LTM cell switching from a serving cell to a target cell. Item

[21] : User equipment (UE) may be configured to receive from a serving distributed unit (DU) information of at least one Layer 1 (L1) / Layer 2 (L2) trigger mobility (LTM) specific active period added by a serving DU to at least one cell discontinuous transmit (DTX) / discontinuous receive (DRX) cycle associated with a serving cell, and to monitor a physical downlink control channel (PDCCH) during at least one added active period to obtain a medium access control (MAC) control element (CE), the MAC CE may contain a cell switching command, and to perform an LTM cell switching from a serving cell to a target cell based on the cell switching command. Item

[22] : The UE described in Item

[21] , wherein the target cell may be a primary target cell and the LTM cell switch may be a first LTM cell switch. The UE may be further configured to receive an LTM fallback configuration from a serving DU, the LTM fallback configuration including a configuration for a secondary target cell different from the target cell, to determine whether the first LTM cell switch was successful, and, based on the determination that the first LTM cell switch failed, to perform a second LTM cell switch from the serving cell to the secondary target cell without a cell switch command from the serving DU, based on the LTM fallback configuration. Item

[23] : A UE described in any one of items

[21] -

[22] , wherein information on at least one additional active period may include an active period coefficient, the active period coefficient may be a coefficient of an existing active period. The UE may be configured to receive information on at least one additional active period by receiving a radio resource control (RRC) reconfiguration message containing an active period coefficient from a central unit (CU) communicably coupled to the serving DU, and by obtaining the active period coefficient from the RRC reconfiguration message. Item

[24] : A UE described in any one of items

[21] -

[22] , where a MAC CE containing a cell switch command may be a second MAC CE, and information for at least one additional active period may include information about when an LTM cell switch is expected. The UE may be configured to receive information for at least one additional active period by receiving a first MAC CE from the serving DU prior to at least one additional active period, the first MAC CE may include information about when an LTM cell switch is expected, and the first MAC CE may be different from the second MAC CE. Item

[25] : The UE described in Item

[23] may be configured to monitor the PDCCH by monitoring the PDCCH and receiving MAC CE from it during multiple active periods added by the Serving DU. Item

[26] : The UE may be configured to monitor the PDCCH and receive MAC CE from it during an additional active period that adapts to the timing of the expected LTM cell switchover, as described in Item

[24] . Item

[27] : The UE described in Item

[22] may be further configured to provide a RRC reconfiguration confirmation message to the Central Unit (CU) based on the determination that the first LTM cell switchover was successful. Item

[28] : A method comprising receiving from a serving distributed unit (DU) information of at least one active period added by a serving DU to at least one cell discontinuous transmit (DTX) / discontinuous receive (DRX) cycle associated with a serving cell; monitoring a physical downlink control channel (PDCCH) during the at least one added active period to obtain a medium access control (MAC) control element (CE), the MAC CE may include a cell switching command; and performing a Layer 1 (L1) / Layer 2 (L2) triggered mobility (LTM) cell switching from a serving cell to a target cell based on the cell switching command. Item

[29] : The method of Item

[28] , wherein the target cell may be a primary target cell and the LTM cell switch may be a first LTM cell switch. The method may further include receiving an LTM fallback configuration from a serving DU, which may include a configuration for a secondary target cell different from the primary target cell; determining whether a first LTM cell switch was successful; and, based on the determination that the first LTM cell switch was unsuccessful, performing a second LTM cell switch from the serving cell to the secondary target cell based on the LTM fallback configuration without a cell switch command from the serving DU. Item

[30] : The method of any one of items

[28] -

[29] , wherein information of at least one additional active period may include an active period coefficient, the active period coefficient may be a coefficient of an existing active period. Receiving information of at least one additional active period may include receiving a radio resource control (RRC) reconfiguration message containing an active period coefficient from a central unit (CU) communicably coupled to a serving DU, and obtaining the active period coefficient from the RRC reconfiguration message. Item

[31] : The method described in any one of items

[28] -

[29] , wherein a MAC CE containing a cell switch command may be a second MAC CE, and information for at least one additional active period may include information about when an LTM cell switch is expected, and receiving information for at least one additional active period may include receiving a first MAC CE from the serving DU prior to at least one additional active period. The first MAC CE may include information about when an LTM cell switch is expected, and the first MAC CE may be different from the second MAC CE. Item

[32] : The method described in Item

[30] , wherein monitoring the PDCCH may include monitoring the PDCCH during multiple active periods added by the Serving DU. Item

[33] : The method described in Item

[31] , which may include monitoring the PDCCH during an additional active period that adapts to the timing of the expected LTM cell switchover. Item

[34] : The method according to Item

[29] , which may further include providing a central unit (CU) with an RRC reconfiguration confirmation message based on a determination that the first LTM cell switchover was successful. Item

[35] : A non-transient computer-readable recording medium that records instructions executable by a user device (UE) to cause the UE to perform a method including receiving from a serving distributed unit (DU) information for at least one active period added by a serving DU to at least one cell discontinuous transmit (DTX) / discontinuous receive (DRX) cycle associated with a serving cell; monitoring a physical downlink control channel (PDCCH) during the at least one added active period to obtain a medium access control (MAC) control element (CE), the MAC CE may include a cell switching command; and performing a Layer 1 (L1) / Layer 2 (L2) triggered mobility (LTM) cell switching from a serving cell to a target cell based on the cell switching command. Item

[36] : A non-temporary computer-readable recording medium as described in Item

[35] , wherein the target cell can be a primary target cell, the LTM cell switch can be a first LTM cell switch, and the method can further include receiving an LTM fallback configuration from a serving DU, the LTM fallback configuration may include a configuration for a secondary target cell different from the primary target cell, determining whether the first LTM cell switch was successful, and, based on the determination that the first LTM cell switch failed, performing a second LTM cell switch from the serving cell to the secondary target cell without a cell switch command from the serving DU, based on the LTM fallback configuration. Item

[37] : A non-temporary computer-readable recording medium as described in any one of items

[35] to

[36] , wherein information for at least one additional active period may include an active period coefficient, the active period coefficient may be a coefficient of an existing active period in at least one cell DTX / DRX cycle, and receiving information for at least one additional active period may include receiving a radio resource control (RRC) reconfiguration message containing an active period coefficient from a central unit (CU) communicably coupled to a serving DU, and obtaining the active period coefficient from the RRC reconfiguration message. Item

[38] : A non-temporary computer-readable recording medium as described in any one of items

[35] -

[36] , wherein a MAC CE containing a cell switching command may be a second MAC CE, and receiving information for at least one additional active period may include receiving a first MAC CE from the serving DU prior to at least one additional active period. The first MAC CE may contain information for at least one additional active period, and the first MAC CE may be different from the second MAC CE. Item

[39] : A non-temporary computer-readable recording medium as described in Item

[37] , which may include monitoring the PDCCH during multiple active periods added by the Serving DU. Item

[40] : A non-transient computer-readable recording medium as described in Item

[38] , which may include monitoring the PDCCH during an additional active period that adapts to the timing of the expected LTM cell switchover.

[0254] In light of the above teachings, it will be understood that many modifications and variations of this disclosure are possible. Within the scope of the attached clauses, it will be clear that this disclosure may be practiced in ways other than those specifically described herein.

Claims

1. Add at least one Layer 1 (L1) / Layer 2 (L2) trigger mobility (LTM) specific active period to at least one cell discontinuous transmit (DTX) / discontinuous receive (DRX) cycle associated with the serving cell, Provide information on the at least one additional active period to at least one user device (UE), Provide the media access control (MAC) control element (CE) to the at least one UE during the at least one additional active period. It includes a serving distributed unit (DU) configured as follows: The MAC CE includes a cell switching command instructing the at least one UE to perform an LTM cell switching from the serving cell to the target cell, system.

2. The Serving DU is Receiving the L1 measurement value from at least one UE, Based on the L1 measurement value, predict the timing of the LTM cell switching during the inactive period, The process involves selecting an active period coefficient corresponding to the predicted timing from a plurality of predetermined active period coefficients based on the L1 measurement value, wherein each of the predetermined active period coefficients is a coefficient for each of the existing active periods. Based on the selected active period coefficient, multiple active periods are added. This is configured to add at least one active period. The system according to claim 1.

3. The Serving DU is Receiving the L1 measurement value from at least one UE, Based on the L1 measurement value, predict the timing at which the LTM cell switchover is expected, Based on the timing at which the LTM cell switchover is expected, an active period is added to the at least one cell DTX / DRX cycle to adapt to the timing at which the cell switchover command needs to be sent to the at least one UE. This is configured to add at least one active period. The system according to claim 1.

4. The aforementioned target cell is a primary target cell, The aforementioned LTM cell switching is the first LTM cell switching, The Serving DU is To provide an LTM fallback configuration to at least one UE, wherein the LTM fallback configuration includes a configuration of a secondary target cell different from the primary target cell. It is further configured to do the following: The LTM fallback configuration is used by the at least one UE to autonomously perform a second LTM cell switch from the serving cell to the secondary target cell without a cell switch command from the serving DU when the first LTM cell switch fails. The system according to claim 1.

5. The Serving DU is To provide the information of the at least one additional active period to a plurality of LTM-configured UEs connected to the serving cell. This is configured to provide the information for the at least one additional active period. The Serving DU is Sending the MAC CE to the multiple LTM-configured UEs during the at least one additional active period. The MAC CE is configured to provide the MAC CE. The system according to claim 1.

6. A central unit (CU) communicatively coupled to the serving DU and the at least one UE. Furthermore, The Serving DU is The active period coefficient is provided to the CU via the F1 interface. This is configured to provide the information for the at least one additional active period. The aforementioned CU, A radio resource control (RRC) reconfiguration message is generated, including the active period coefficient and the configuration of the target cell. Provide the RRC reconstruction message to the at least one UE. It is configured in such a way. The system according to claim 2.

7. The MAC CE including the cell switching command is a second MAC CE, The Serving DU is To generate a first MAC CE including the information of the timing at which the LTM cell switching is expected, Providing the first MAC CE to the at least one UE before the at least one additional active period This is configured to provide the information for the at least one additional active period. The first MAC CE is different from the second MAC CE. The system according to claim 3.

8. The Serving DU is Generate an LTM Radio Network Temporary Identifier (RNTI) unique to at least one UE composed of LTMs, Downlink control information (DCI) including information on the expected transmission time of the MAC CE is generated. Based on the LTM RNTI, the DCI is scrambled. Provide the scrambled DCI to the UE before the at least one additional active period. It is further configured in the following way: The system according to claim 6.

9. The serving DU is further configured to provide the LTM RNTI to the CU via the F1 interface, The CU is configured to generate the RRC reconstruction message, which includes the LTM RNTI, the active period coefficient, and the configuration of the target cell. The system according to claim 8.

10. The L1 measurement includes the value of the reference signal received power (RSRP) associated with the serving cell and at least one of the one or more candidate cells, The Serving DU is The RSRP value is compared with a predetermined threshold, Based on the determination that the value of RSRP is equal to the predetermined threshold, it is determined that the LTM cell switchover is expected to occur at a first predetermined timing within the next inactive period. Based on the determination that the value of RSRP is greater than the predetermined threshold, it is determined that the LTM cell switchover is expected at a second predetermined timing within the next inactive period. This is configured to predict the timing at which the LTM cell switchover is expected to occur. The system according to claim 3.

11. The system according to claim 3, wherein the serving DU is configured to predict the timing at which the LTM cell switchover is expected, based on at least one artificial intelligence (AI) / machine learning (ML) model.

12. Adding at least one Layer 1 (L1) / Layer 2 (L2) trigger mobility (LTM) specific active period to at least one cell discontinuous transmit (DTX) / discontinuous receive (DRX) cycle associated with the serving cell, To provide information on the at least one additional active period to at least one user device (UE), To provide the media access control (MAC) control element (CE) to the at least one UE during the at least one additional active period. Includes, The MAC CE includes a cell switching command instructing the at least one UE to perform an LTM cell switching from the serving cell to the target cell, method.

13. The addition of the aforementioned at least one active period is Receiving the L1 measurement value from at least one UE, Based on the L1 measurement value, predict the timing of the LTM cell switching during the inactive period, The process involves selecting an active period coefficient corresponding to the predicted timing from a plurality of predetermined active period coefficients based on the L1 measurement value, wherein each of the predetermined active period coefficients is a coefficient for each of the existing active periods. Based on the selected active period coefficient, multiple active periods are added. including, The method according to claim 12.

14. The addition of the aforementioned at least one active period is Receiving the L1 measurement value from at least one UE, Based on the L1 measurement value, predict the timing at which the LTM cell switchover is expected, Based on the timing at which the LTM cell switchover is expected, an active period is added to the at least one cell DTX / DRX cycle to adapt to the timing at which the cell switchover command needs to be sent to the at least one UE. The method according to claim 12, including the method described in claim 12.

15. The aforementioned target cell is a primary target cell, The aforementioned LTM cell switching is the first LTM cell switching, The method described above is To provide an LTM fallback configuration to at least one UE, wherein the LTM fallback configuration includes a configuration of a secondary target cell different from the primary target cell. It further includes, The LTM fallback configuration is used by the at least one UE to autonomously perform a second LTM cell switch from the serving cell to the secondary target cell without a cell switch command when the first LTM cell switch fails. The method according to claim 12.

16. Providing the information for the at least one additional active period is To provide the information of the at least one additional active period to a plurality of LTM-configured UEs connected to the serving cell. Includes, Providing the MAC CE as described above is Sending the MAC CE to the multiple LTM-configured UEs during the at least one additional active period. including, The method according to claim 12.

17. Providing the information for the at least one additional active period is To generate a radio resource control (RRC) reconfiguration message including the active period coefficient and the configuration of the target cell, To provide the RRC reconstruction message to at least one of the aforementioned UEs The method according to claim 13, including the method described in claim 13.

18. The MAC CE including the cell switching command is a second MAC CE, Providing the information for the at least one additional active period is To generate a first MAC CE including the information of the timing at which the LTM cell switching is expected, Providing the first MAC CE to the at least one UE before the at least one additional active period Includes, The first MAC CE is different from the second MAC CE. The method according to claim 14.

19. To generate an LTM Radio Network Temporary Identifier (RNTI) unique to at least one UE composed of LTMs, To generate downlink control information (DCI) including information on the expected transmission time of the MAC CE, Scrambling the DCI based on the LTM RNTI, Providing the scrambled DCI to the UE before the at least one additional active period, The RRC reconstruction message is generated to include the LTM RNTI, the active period coefficient, and the configuration of the target cell. The method according to claim 17, further comprising:

20. Adding at least one Layer 1 (L1) / Layer 2 (L2) trigger mobility (LTM) specific active period to at least one cell discontinuous transmit (DTX) / discontinuous receive (DRX) cycle associated with the serving cell, To provide information on the at least one additional active period to at least one user device (UE), To provide the media access control (MAC) control element (CE) to the at least one UE during the at least one additional active period. A method including, The MAC CE includes a cell switching command instructing the at least one UE to perform an LTM cell switching from the serving cell to the target cell, The method records instructions that can be executed by at least one network node so that the at least one network node executes them. Non-temporary computer-readable recording medium.

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