Dual connectivity and conditional l1 / l2 triggered mobility inter-working

Abstract

A method includes receiving one of: an indication that dual connectivity is configured, or an indication of potential conditional Layer-1 / Layer-2 triggered mobility (LTM) configuration; reading a configurable value indicating that co-existence between dual connectivity and conditional LTM is not permitted; in case of receiving the indication that dual connectivity is configured, determining that conditional LTM cannot be configured; and in case of receiving the indication of potential conditional LTM configuration, determining that dual connectivity cannot be configured for a candidate cell.

Description

DUAL CONNECTIVITY AND CONDITIONAL L1 / L2 TRIGGERED MOBILITY INTER-WORKINGFIELD

[0001] Various example embodiments relate generally to wireless networks and, more particularly, to dual connectivity and conditional L1 / L2 triggered mobility inter- working.BACKGROUND

[0002] Wireless networking provides significant advantages for user mobility. A user’s ability to remain connected while on the move provides advantages not only for the user, but also provides greater efficiency and productivity for society as a whole. As expectations for connection reliability, data speed, and power consumption, become more demanding, technology for wireless networking must also keep pace with such expectations. Accordingly, there is continuing interest in improving wireless networking technology.SUMMARY

[0003] In an aspect of the present disclosure, a method includes receiving one of: an indication that dual connectivity is configured, or an indication of potential conditional Layer- 1 / Layer-2 triggered mobility (LTM) configuration; reading a configurable value indicating that co-existence between dual connectivity and conditional LTM is not permitted; in case of receiving the indication that dual connectivity is configured, determining that conditional LTM cannot be configured; and in case of receiving the indication of potential conditional LTM configuration, determining that dual connectivity cannot be configured for a candidate cell.

[0004] In an aspect of the method, the indication that dual connectivity is configured indicates whether the configured dual connectivity for a candidate cell is for an intra-centralized-unit candidate cell or for an inter-centralized unit candidate cell.

[0005] In an aspect of the method, the configurable value indicates co-existence between dual connectivity and subsequent conditional LTM.

[0006] In an aspect of the method, the method further includes: reading a configurable value indicating that co-existence between dual connectivity and subsequent LTM is not permitted.

[0007] In an aspect of the method, the configurable value is further configurable to indicate one of: co-existence between dual connectivity and conditional LTM is only permitted for intercentralized unit candidate cells, co-existence between dual connectivity and conditional LTM is only permitted for intra-centralized unit candidate cells, or co-existence between dual connectivity and conditional LTM is permitted for intra-centralized unit or inter- centralized unit candidate cells.

[0008] In an aspect of the method, the indication that dual connectivity is configured and the configurable value indicating that co-existence between dual connectivity and conditional LTM is not permitted, are transmitted by a source centralized unit of a master node (MN-S-CU) and are received by a source distributed unit of the master node (MN-S-DU).

[0009] In an aspect of the method, the indication that dual connectivity is configured and the configurable value indicating that co-existence between dual connectivity and conditional LTM is not permitted, are transmitted by a centralized unit of a source master-node (S-MN-CU) and are received by a distributed unit of the source master-node (S-MN-DU).

[0010] In an aspect of the method, the indication that dual connectivity is configured is transmitted by the S-MN-CU based on the S-MN-CU receiving an indication that a secondary node was activated.

[0011] In an aspect of the method, the indication that a secondary node was activated is transmitted by a centralized unit of a target master-node (T-MN-CU).

[0012] In an aspect of the method, the indication of potential conditional LTM configuration and the configurable value indicating that co-existence between dual connectivity and conditional LTM is not permitted, are transmitted by a centralized unit of a source master-node (S-MN-CU) and are received by a centralized unit of a target master-node (T-MN-CU).

[0013] In an aspect of the method, the S-MN-CU decides to possibly request a distributed unit of the source master-node (S-MN-DU) to configure conditional LTM, where the S-MN-CU generates the indication of potential conditional LTM configuration based on the decision.

[0014] In an aspect of the method, the method includes receiving, by the T-MN-CU, from the S-MN-CU, an indication that conditional LTM was prepared.

[0015] In accordance with aspects of the present disclosure, a method includes: receiving, by a first apparatus from a second apparatus, for a Layer- 1 / Layer-2 triggered mobility (LTM) candidate cell, one of: an indication that conditional LTM configuration is not permitted, or an indication that dual connectivity is not permitted; in case of receiving the indication thatconditional LTM configuration is not permitted, determining that conditional LTM cannot be configured and transmitting, by the first apparatus toward the second apparatus, a user equipment configuration not comprising conditional LTM configuration; and in case of receiving the indication that dual connectivity is not permitted, determining that dual connectivity cannot be configured and transmitting, by the first apparatus toward the second apparatus, a user equipment configuration not comprising dual connectivity configuration.

[0016] In an aspect of the method, the method further includes determining, by the first apparatus, that co-existence between dual connectivity and conditional LTM is not permitted based on at least one of: a preconfigured rule indicating that co-existence between dual connectivity and conditional LTM is not permitted, or a value, received from the second apparatus, indicating that co-existence between dual connectivity and conditional LTM is not permitted.

[0017] In accordance with aspect of the present disclosure, an apparatus includes: at least one processor, and at least one memory having stored thereon instructions which, when executed by the at least one processor, cause the apparatus at least to perform a method as in any one of the preceding methods.

[0018] In accordance with aspects of the present disclosure, a non-transitory processor- readable medium has stored thereon instructions which, when executed by at least one processor of an apparatus, causes the apparatus at least to perform a method as in any one of the preceding methods.

[0019] According to some aspects, there is provided the subject matter of the independent claims. Some further aspects are defined in the dependent claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Some example embodiments will now be described with reference to the accompanying drawings.

[0021] FIG. 1 is a diagram of an example embodiment of wireless networking between a network system and a user equipment (UE), according to one illustrated aspect of the disclosure;

[0022] FIG. 2 is a diagram of example components of a network system, according to one illustrated aspect of the disclosure;

[0023] FIG. 3 is a diagram of an example embodiment of signals and operations of a scenario involving intra-MN / intra-CU conditional LTM in which conditional LTM is prevented when DC is configured, according to one illustrated aspect of the disclosure;

[0024] FIG. 4 is a diagram of an example embodiment of signals and operations of a scenario involving inter-MN / inter-CU conditional LTM in which conditional LTM is prevented when DC is configured, according to one illustrated aspect of the disclosure;

[0025] FIG. 5 A and FIG. 5B is a diagram of an example embodiment of signals and operations of a scenario involving inter-MN / inter-CU conditional LTM in which DC is prevented when conditional LTM is configured, according to one illustrated aspect of the disclosure;

[0026] FIG. 6 is a diagram of an example block diagram of components of an apparatus, according to one illustrated aspect of the present disclosure;

[0027] FIG. 7 is a diagram of an example dual connectivity scenario, according to one illustrated aspect of the disclosure; and

[0028] FIG. 8 is a diagram of an example LTM handover scenario, according to one illustrated aspect of the disclosure.DETAILED DESCRIPTION

[0029] In the following description, certain specific details are set forth in order to provide a thorough understanding of disclosed aspects. However, one skilled in the relevant art will recognize that aspects may be practiced without one or more of these specific details or with other methods, components, materials, etc. In other instances, well-known structures associated with transmitters, receivers, or transceivers have not been shown or described in detail to avoid unnecessarily obscuring descriptions of the aspects.

[0030] Reference throughout this specification to “one aspect” or “an aspect” means that a particular feature, structure, or characteristic described in connection with the aspect is included in at least one aspect. Thus, the appearances of the phrases “in one aspect” or “in an aspect” in various places throughout this specification are not necessarily all referring to the same aspect. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more aspects.

[0031] Embodiments described in the present disclosure may be implemented in wireless networking apparatuses, such as, without limitation, apparatuses utilizing WorldwideInteroperability for Microwave Access (WiMAX), Global System for Mobile communications (GSM, 2G), GSM EDGE radio access Network (GERAN), General Packet Radio Service (GRPS), Universal Mobile Telecommunication System (UMTS, 3G) based on basic wideband-code division multiple access (W-CDMA), high-speed packet access (HSPA), Long Term Evolution (LTE), LTE- Advanced, enhanced LTE (eLTE), 5G New Radio (5G NR), 5G Advance, 6G (and beyond) and 802.1 lax (Wi-Fi 6), among other wireless networking systems. The term ‘eLTE’ here denotes the LTE evolution that connects to a 5G core. LTE is also known as evolved UMTS terrestrial radio access (EUTRA) or as evolved UMTS terrestrial radio access network (EUTRAN).

[0032] The present disclosure may use the term “serving network device” to refer to a network node or network device (or a portion thereof) that services a UE. As used herein, the terms “transmit to,” “receive from,” and “cooperate with,” (and their variations) include communications that may or may not involve communications through one or more intermediate devices or nodes. The term “acquire” (and its variations) includes acquiring in the first instance or reacquiring after the first instance. The term “connection” may mean a physical connection or a logical connection.

[0033] The present disclosure uses 5G NR as an example of a wireless network and may use smartphones and / or extended reality headsets as an example of UEs. It is intended and shall be understood that such examples are merely illustrative, and the present disclosure is applicable to other wireless networks and user equipment.

[0034] As described in more detail below, the present disclosure addresses aspects of signals and operations relating to inter- working of dual connectivity and conditional Layer- 1 / Layer-2 triggered mobility.

[0035] FIG. 1 is a diagram depicting an example of wireless networking between a network system 100 and a user equipment (UE) 150. The network system 100 may include one or more network nodes 120, one or more servers 110, and / or one or more network equipment 130 (e.g., test equipment). The network nodes 120 will be described in more detail below. As used herein, the term “network apparatus” may refer to any component of the network system 100, such as the server 110, the network node 120, the network equipment 130, any component(s) of the foregoing, and / or any other component(s) of the network system 100. Examples of network apparatuses include, without limitation, apparatuses implementing aspects of 5G NR, among others. The present disclosure describes embodiments related to 5GNR and embodiments that involve aspects defined by 3rd Generation Partnership Project (3GPP). However, it is contemplated thatembodiments relating to other wireless networking technologies are encompassed within the scope of the present disclosure.

[0036] The following description provides further details of examples of network nodes. In a 5G NR network, a gNodeB (also known as gNB) may include, e.g., a node that provides new radio (NR) user plane and control plane protocol terminations towards the UE and that is connected via a NG interface to the 5G core (5GC), e.g., according to 3GPP TS 38.300 V16.6.0 (2021-06) section 3.2, which is hereby incorporated by reference herein.

[0037] A gNB supports various protocol layers, e.g., Layer 1 (LI) - physical layer, Layer 2 (L2), and Layer 3 (L3).

[0038] The layer 2 (L2) of NR is split into the following sublayers: Medium Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP) and Service Data Adaptation Protocol (SDAP), where, e.g.: o The physical layer offers to the MAC sublayer transport channels; o The MAC sublayer offers to the RLC sublayer logical channels; o The RLC sublayer offers to the PDCP sublayer RLC channels; o The PDCP sublayer offers to the SDAP sublayer radio bearers; o The SDAP sublayer offers to 5GC quality of service (QoS) flows; o Control channels include broadcast control channel (BCCH) and physical control channel (PCCH).

[0039] Layer 3 (L3) includes, e.g., radio resource control (RRC), e.g., according to 3GPP TS 38.300 V16.6.0 (2021-06) section 6, which is hereby incorporated by reference herein.

[0040] A gNB central unit (gNB-CU) includes, e.g., a logical node hosting, e.g., radio resource control (RRC), service data adaptation protocol (SDAP), and packet data convergence protocol (PDCP) protocols of the gNB or RRC and PDCP protocols of the en-gNB, that controls the operation of one or more gNB distributed units (gNB-DUs). The gNB-CU terminates the Fl interface connected with the gNB-DU. A gNB-CU may also be referred to herein as a CU, a central unit, a centralized unit, or a control unit.

[0041] A gNB Distributed Unit (gNB-DU) includes, e.g., a logical node hosting, e.g., radio link control (RLC), media access control (MAC), and physical (PHY) layers of the gNB or en- gNB, and its operation is partly controlled by the gNB-CU. One gNB-DU supports one or multiple cells. One cell is supported by only one gNB-DU. The gNB-DU terminates the Fl interfaceconnected with the gNB-CU. A gNB-DU may also be referred to herein as DU or a distributed unit.

[0042] As used herein, the term “network node” may refer to any of a gNB, a gNB-CU, or a gNB-DU, or any combination of them. A RAN (radio access network) node or network node such as, e.g., a gNB, gNB-CU, or gNB-DU, or parts thereof, may be implemented using, e.g., an apparatus with at least one processor and / or at least one memory with processor-readable instructions (“program”) configured to support and / or provision and / or process CU and / or DU related functionality and / or features, and / or at least one protocol (sub-)layer of a RAN (radio access network), e.g., layer 2 and / or layer 3. Different functional splits between the central and distributed unit are possible. An example of such an apparatus and components will be described in connection with FIG. 6 below.

[0043] The gNB-CU and gNB-DU parts may, e.g., be co-located or physically separated. The gNB-DU may even be split further, e.g., into two parts, e.g., one including processing equipment and one including an antenna. A central unit (CU) may also be called baseband unit / radio equipment controller / cloud-RAN / virtual-RAN (BBU / REC / C-RAN / V-RAN), open-RAN (O- RAN), or part thereof. A distributed unit (DU) may also be called remote radio head / remote radio unit / radio equipment / radio unit (RRH / RRU / RE / RU), or part thereof. Hereinafter, in various example embodiments of the present disclosure, a network node, which supports at least one of central unit functionality or a layer 3 protocol of a radio access network, may be, e.g., a gNB-CU. Similarly, a network node, which supports at least one of distributed unit functionality or a layer 2 protocol of the radio access network, may be, e.g., a gNB-DU.

[0044] A gNB-CU may support one or multiple gNB-DUs. A gNB-DU may support one or multiple cells and, thus, could support a serving cell for a user equipment (UE) or support a candidate cell for handover, dual connectivity, and / or carrier aggregation, among other procedures.

[0045] The user equipment (UE) 150 may be or include a wireless or mobile device, an apparatus with a radio interface to interact with a RAN (radio access network), a smartphone, an in-vehicle apparatus, an loT device, or a M2M device, among other types of user equipment. Such UE 150 may include: at least one processor; and at least one memory including program code; where the at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to perform certain operations, such as, e.g., RRC connection to the RAN. An example of components of a UE will be described in connection withFIG. 6. In embodiments, the UE 150 may be configured to generate a message (e.g., including a cell ID) to be transmitted via radio towards a RAN (e.g., to reach and communicate with a serving cell). In embodiments, the UE 150 may generate and transmit and receive RRC messages containing one or more RRC PDUs (packet data units). Persons skilled in the art will understand RRC protocol as well as other procedures a UE may perform.

[0046] With continuing reference to FIG. 1, in the example of a 5G NR network, the network system 100 provides one or more cells, which define a coverage area of the network system 100. As described above, the network system 100 may include a gNB of a 5G NR network or may include any other apparatus configured to control radio communication and manage radio resources within a cell. As used herein, the term “resource” may refer to radio resources, such as a resource block (RB), a physical resource block (PRB), a radio frame, a subframe, a time slot, a sub-band, a frequency region, a sub-carrier, a beam, etc. In embodiments, the network node 120 may be called a base station.

[0047] FIG. 1 provides an example and is merely illustrative of a network system 100 and a UE 150. Persons skilled in the art will understand that the network system 100 includes components not illustrated in FIG. 1 and will understand that other user equipment may be in communication with the network system 100.

[0048] FIG. 2 is a block diagram of example components of the network system 100 of FIG. 1. A 5G NR network may be described as an example of the network system 100, and it is intended that aspects of the following description shall be applicable to other types of network systems, as well. The network system may operate in accordance with the signals and connections shown in FIG. 1 such that the UE 150 is in communication with the network system 100 through the radio access network 225. Additionally, the network system may be divided into user plane components and functions and control plane components and functions, as shown and described herein. Unless indicated otherwise, the terms “component”, “function”, and “service” may be used interchangeably herein, and they may refer to and be implemented by instructions executed by one or more processors.

[0049] Example functions of the components are described below. The example functions are merely illustrative, and it shall be understood that additional operations and functions may be performed by the components described herein. Additionally, the connections between components may be virtual connections over service-based interfaces such that any componentmay communicate with any other component. In this manner, any component may act as a service “producer,” for any other component that is a service “consumer,” to provide services for network functions.

[0050] For example, a core network 210 is described in the control plane of the network system. The core network 210 may include an authentication server function (AUSF) 211, an access and mobility function (AMF) 212, and a session management function (SMF) 213. The core network 210 may also include a network slice selection function (NSSF) 214, a network exposure function (NEF) 215, a network repository function (NRF) 216, and a unified data management function (UDM) 217, which may include a uniform data repository (UDR) 224.

[0051] Additional components and functions of the core network 210 may include an application function 218, policy control function (PCF) 219, network data analytics function (NWDAF) 220, analytics data repository function (ADRF) 221, management data analytics function (MDAF) 222, and operations and management function (0AM) 223.

[0052] The user plane includes the UE 150, a radio access network (RAN) 225, a user plane function (UPF) 226, and a data network (DN) 227. The RAN 225 may include one or more components described in connection with FIG. 1, such as one or more network nodes. However, the RAN 225 may not be limited to such components. The UPF 226 provides connection for data being transmitted over the RAN 225. The DN 226 identifies services from service providers, Internet access, and third party services, for example.

[0053] The AMF 212 processes connection and mobility tasks. The AUSF 211 receives authentication requests from the AMF 212 and interacts with UDM 217 to authenticate and validate network responses for determination of successful authentication. The SMF 213 conducts packet data unit (PDU) session management, as well as manages session context with the UPF 226.

[0054] The NSSF 214 may select a network slicing instance (NSI) and determine the allowed network slice selection assistance information (NSSAI). This selection and determination is utilized to set the AMF 212 to provide service to the UE 150. The NEF 215 secures access to network services for third parties to create specialized network services. The NRF 216 acts as a repository to store network functions to allow the functions to register with and discover each other.

[0055] The UDM 217 generates authentication vectors for use by the AUSF 211 and ADM 212 and provides user identification handling. The UDM 217 may be connected to the UDR 224 which stores data associated with authentication, applications, or the like. The AF 218 provides application services to a user (e.g., streaming services, etc.). The PCF 219 provides policy control functionality. For example, the PCF 219 may assist in network slicing and mobility management, as well as provide quality of service (QoS) and charging functionality.

[0056] The NWDAF 220 collects data (e.g., from the UE 150 and the network system) to perform network analytics and provide insight to functions that utilize the analytics in the providing of services. The ADRF 221 allows the storage, retrieval, and removal of data and analytics by consumers. The MD AF 222 provides additional data analytics services for network functions. The 0AM 223 provides provisioning and management processing functions to manage elements in or connected to the network (e.g., UE 150, network nodes, etc.).

[0057] FIG. 2 is merely an example of components of a network system, and variations are contemplated to be within the scope of the present disclosure. In embodiments, the network system may include other components not illustrated in FIG. 2. In embodiments, the network system may not include every component illustrated in FIG. 2. In embodiments, the components and connections may be implemented with different connections than those illustrated in FIG. 2. Such and other embodiments are contemplated to be within the scope of the present disclosure.

[0058] As mentioned above, the present disclosure addresses aspects of signals and operations relating to inter- working of dual connectivity and conditional Layer- 1 / Layer-2 triggered mobility.

[0059] FIG. 7 is a diagram depicting an example of dual connectivity (DC) of a user equipment apparatus (UE) 110 with a master node (MN) 720 and a secondary node (SN) 730. The UE 110 may include, but is not limited to, a smartphone, a tablet, portable computers, vehicle-mounted wireless terminal devices, an Internet of Things (loT) device, and / or a watch or other wearable device, among others. Dual connectivity allows a UE 110 to simultaneously connect to two network nodes. In embodiments, the MN 720 and / or the SN 730 may be a 5G New Radio (NR) node (e.g., gNB) or an LTE network node (e.g., eNB), among other types of nodes. In embodiments, the MN 720 and / or SN 730 may be base stations.

[0060] In embodiments, the MN 720 connects to a core network, such as a 5G core (5GC), and provides a control plane connection between a UE 110 and the core network, while the SN 730 connects to the MN 720 (e.g., via an Xn interface) and provides additional resources for user planetraffic. In embodiments, the MN 720 handles signaling messages, such as radio resource control (RRC) signaling messages. In embodiments, using signaling radio bearers (SRB) for LTE networks (e.g., SRBO, SRB1, and / or SRB2) and / or for 5G NR networks (e.g., SRB3), the SN 730 may handle signaling messages, such as RRC signaling messages, as well. Persons skilled in the art will understand RRC and SRB.

[0061] Carrier aggregation may be used in conjunction with dual connectivity. Carrier aggregation enables a UE 110 to simultaneously connect with multiple cells so as to operate at multiple frequencies at the same time. In embodiments, the multiple cells may be located at a single base station and / or at a common location (e.g., small cells or femtocells at a facility). One or more cells that may be usable by a UE under carrier aggregation may be referred to as a “cell group.” When carrier aggregation is used with dual connectivity, the master node and / or the secondary node may have a cell group. A cell group of a master node may be referred to as a master cell group (MCG), and a cell group of a secondary node may be referred to as a secondary cell group (SCG). As shown in FIG. 1, the MCG includes a primary cell (PCell) and may include one or more secondary cells (SCell). The SCG includes a primary cell of a secondary cell group (PSCell) and may include one or more secondary cells (SCell). Persons skilled in the art will understand the characteristics and functions of such cells and cell groups.

[0062] FIG. 8 depicts an example of a handover scenario involving dual connectivity (DC), which may be a handover scenario involving Layer 1 / Layer 2-Triggered Mobility (LTM). Handover (HO) refers to a procedure that transitions the servicing of a UE from a source node or cell to a target node or cell. HO may be performed, for example, when a UE transits between cells, among other scenarios. Persons skilled in the art will understand LTM. FIG. 8 shows a UE 110, a source MN 820, a source SN 830, a target MN 840.

[0063] The proposed standards of 5G Advance have set forth certain aspects of inter-working between dual connectivity and intra-CU or inter-CU LTM. Intra-CU LTM refers to LTM where the source node and the target node are both served by the same CU. Inter-CU LTM refers to LTM where the source node and the target node are served by different CUs. The proposed standards of 5G Advance have also set forth conditional LTM. Conditional LTM is a process which allows the UE 110 to be preconfigured with conditions for triggering a handover. The UE 110 monitors the conditions and when the conditions are satisfied, the UE triggers the handover. Complications may occur in various scenarios involving DC and conditional LTM.

[0064] The present disclosure addresses aspects of signals and operations relating to interworking of dual connectivity and conditional LTM both for intra-CU and inter-CU scenarios. As used herein, the term “intra-CU” may be used interchangeably with “intra-MN” (intra-master node), and the term “inter-CU” may be used interchangeably with “inter-MN” (inter-master node). In aspects of the present disclosure, the disclosed signals and operations may prevent a network from configuring dual connectivity (DC) and conditional LTM at the same time. Thus, the disclosed signals and operations may enable a network to prevent configuring conditional LTM if DC is configured, or prevent configuring DC if conditional LTM is configured.

[0065] For example, in case intra-CU or inter-CU conditional LTM is configured with single connectivity, the candidate master node (MN) may configure dual connectivity for a candidate PCell of a master cell group (MCG). In case the target MN configures DC, the conditional LTM would need to be prevented, and vice-versa, which requires signalling. As described below, such signalling can be configurable in controlling the behaviour of preventing or allowing simultaneous conditional LTM and DC.

[0066] Aspects of the present disclosure introduces signalling which would determine the behaviour of a source and target MN CU to determine whether to allow or prevent DC at the candidate cell or MN if there is a possibility that conditional LTM could be potentially configured for the UE towards the candidate cell due to radio link failure (RLF) or HO failures detected previously at the cell edges. Aspects of the present disclosure also determine the behaviour of the source and target MN CU to determine whether to allow or prevent configuration for conditional LTM if DC has been decided to be configured for the candidate cell or candidate MN based on the cell group quality of service (QoS) requirement.

[0067] In the following description and in the accompanying drawings, various aspects of the present disclosure may be referred to or labelled as Emb-xx, which xx may be la, lb, 2a, 2b, etc. Any aspects may be implemented individually or may be implemented together with one or more other aspects.

[0068] FIG. 3 is a flow diagram of a scenario involving intra-MN / intra-CU conditional LTM in which conditional LTM is prevented when DC is configured. In various embodiments, the components depicted in FIG. 3 may correspond to similar components described above in FIGS.1 and 2. It will be understood that a described signal may have associated operations and a described operation may have associated signals.

[0069] In FIG. 3, the terms have the following meanings:MN-S-DU: master-node source DUMN-T-DU: master-node target DU MN-S-CU: master-node source CU SN-CU: secondary-node CU.

[0070] At operation 301, the UE is configured with single connectivity.

[0071] At operations 302 and 303, the UE reports L3 measurements to MN-S-CU via MN-S-DU, and the MN-S-CU receives the L3 measurements from the UE via MN-S-DU.

[0072] At operation 304, the MN-S-CU decides to configure a target cell in MN-T-DU as preparation for intra-MN LTM. In embodiments, the MN-S-CU configures a target PCell in MN- T-DU as preparation for the intra-MN MCG LTM. The MN-T-DU may prepare one or more cells, and cell2 and cell3 are illustrated examples of two cells that may be prepared.

[0073] Operations 305-308 relate to the MN-S-CU also deciding to configure dual connectivity (DC) for the cell (e.g., candidate PCell) under MN-T-DU while preparing one or more cells for LTM.

[0074] At operation 305, the MN-S-CU transmits a secondary-node (SN) Addition Request signal towards the SN-CU, and the SN-CU receives the SN Addition Request signal from the MN- S-CU.

[0075] At operation 306, the SN-CU transmits a SN Addition Request Acknowledgment (Ack) signal to the MN-S-CU, and the MN-S-CU receives the SN Addition Request Ack signal from the SN-CU.

[0076] At operation 307, the MN-S-CU transmits a UE Context Set Up Request signal, among other signals, to the MN-T-DU to prepare for LTM.

[0077] In accordance with aspects of the present disclosure, at operation 307, the MN-S-CU also transmits a DC Configured Indication signal (indicated as Aspect- la) and an Available Mobility Configuration signal (indicated as Aspect-2a). The DC Configured Indication signal indicates that DC has been configured. The Available Mobility Configuration signal contains a DC and conditional LTM Co-Existence Indication that is set to a value (e.g., bit value “00”) that indicates that DC and conditional LTM cannot be configured at the same time (e.g., for a target cell). The DC and conditional LTM Co-Existence Indication can have other values that indicate that DC and conditional LTM may be configured at the same time (e.g., for a target cell). Atoperation 307, the MN-T-DU receives the UE Context Set Up Request signal, the DC Configured Indication signal, and the Available Mobility Configuration signal from the MN-S-CU.

[0078] At operation 308, the MN-S-CU transmits a UE Context Setup Response signal to the MN-S-CU, and the MN-S-CU receives the UE Context Setup Response signal from the MN-T- DU.

[0079] At operation 309, the MN-S-CU transmits a UE Context Modification Request signal, along with other signals, to the MN-S-DU.

[0080] In accordance with aspects of the present disclosure, at operation 309, the MN-S-CU also transmits a DC Configured Indication signal (indicated as Aspect- la) and an Available Mobility Configuration signal (indicated as Aspect-2a). The DC Configured Indication signal indicates that DC has been configured. The Available Mobility Configuration signal contains a DC and conditional LTM Co-Existence Indication that is set to a value (e.g., bit value “00”) that indicates that DC and conditional LTM cannot be configured at the same time (e.g., for a target cell). The DC and conditional LTM Co-Existence Indication can have other values that indicate that DC and conditional LTM may be configured at the same time (e.g., for a target cell). At operation 309, the MN-S-DU receives the UE Context Modification Request signal, the DC Configured Indication signal, and the Available Mobility Configuration signal from the MN-S- CU.

[0081] At operation 310, and in accordance with aspects of the present disclosure, the MN-S- DU reads the DC Configured Indication (Aspect-la), which indicates that DC was configured (e.g., for a target cell), and reads the DC and Conditional Co-Existence Indication (Aspect- 2a), which was set to bit value “00,” indicating that DC and conditional LTM cannot be configured at the same time (e.g., for the target cell).

[0082] At operation 311, and in accordance with aspects of the present disclosure, based on the received the DC Configured Indication and the Available Mobility Configuration, the MN-S- DU determines that it cannot configure conditional LTM because DC and conditional LTM cannot be configured at the same time and DC has already been configured.

[0083] At operation 312, the MN-S-DU transmits a UE Context Modification Response signal with channel state information (CSI) reporting configuration for conventional intra-CU LTM (e.g., intra-CU MCG LTM) to the MN-S-CU, and the MN-S-CU receives the UE Context Modification Response signal from the MN-S-DU.

[0084] The operations of FIG. 3 are merely illustrative, and variations are contemplated to be within the scope of the present disclosure. For example, in embodiments, the determination on whether conditional LTM can be configured is performed at the MN-S-CU, and then the MN-S- CU provides an indication to MN-S-DU on whether conditional LTM configuration is allowed. In such embodiments, the MN-S-DU can provide conditions for only the candidate cells where conditional LTM coexistence is allowed. Such embodiments can lead to hard prevention of configuration of conditional LTM if DC is configured at the candidate cell, or can be used to prevent DC if conditional LTM is already or would potentially be configured at the candidate cell.

[0085] In embodiments, the operations may include other operations not illustrated in FIG. 3. In embodiments, the operations may not include every operation illustrated in FIG. 3. In embodiments, the operations may be implemented in a different order than that illustrated in FIG. 3. In embodiments, the names of various signals and values may be different from what is described above. Such and other embodiments are contemplated to be within the scope of the present disclosure. Persons of skill in the art will appreciate that, although various example components are described as performing various functions, other components may perform those functions described in FIG. 3.

[0086] FIG. 4 is a flow diagram of a scenario involving inter-MN / inter-CU conditional LTM in which conditional LTM is prevented when DC is configured. In various embodiments, the components depicted in FIG. 4 may correspond to similar components described above in FIGS. 1 and 2. It will be understood that a described signal may have associated operations and a described operation may have associated signals.

[0087] In FIG. 4, the terms have the following meanings:S-MN-DU: source master-node DU T-MN-DU: target master-node DU S-MN-CU: source master- node CU T-MN-CU: target master-node CU SN-CU: secondary-node CU.

[0088] At operation 401, the UE is configured with single connectivity.

[0089] At operations 402 and 403, the UE reports L3 measurements to S-MN-CU via S-MN-DU, the S-MN-CU receives the L3 measurements from the UE via S-MN-DU.

[0090] At operation 404, the S-MN-CU decides to configure a target cell in T-MN-DU aspreparation for inter-MN LTM. In embodiments, the S-MN-CU decides to configure a target PCell in T-MN-DU as preparation for the inter-MN MCG LTM. The T-MN-DU may prepare one or more cells, and cell2 and cell3 are illustrated examples of two cells that may be prepared.

[0091] At operation 405, the S-MN-CU transmits a LTM handover (HO) Request signal to T- MN-CU, and T-MN-CU receives the LTM HO Request signal from the S-MN-CU.

[0092] Operations 406-409 relate to the T-MN-CU also deciding to configure dual connectivity (DC) for the cell (e.g., candidate PCell) under T-MN-DU while preparing one or more cells for LTM.

[0093] At operation 406, the T-MN-CU transmits a secondary-node (SN) Addition Request signal towards the SN-CU, and the SN-CU receives the SN Addition Request signal from the T- MN-CU.

[0094] At operation 407, the SN-CU transmits a SN Addition Request Acknowledgment (Ack) signal to the T-MN-CU, and the T-MN-CU receives the SN Addition Request Ack signal from the SN-CU.

[0095] At operation 408, the T-MN-CU transmits a UE Context Set Up Request signal, along with other signals, to the T-MN-DU to prepare for LTM

[0096] In accordance with aspects of the present disclosure, at operation 408, the T-MN-CU also transmits a DC Configured Indication signal (indicated as Aspect- la) and an Available Mobility Configuration signal (indicated as Aspect-2a). As mentioned above, the DC Configured Indication signal indicates that DC has been configured. The Available Mobility Configuration signal contains a DC and conditional LTM Co-Existence Indication that is set to a value (e.g., bit value “00”) that indicates that DC and conditional LTM cannot be configured at the same time (e.g., for a target cell). The DC and conditional LTM Co-Existence Indication can have other values that indicate that DC and conditional LTM may be configured at the same time (e.g., for a target cell). At operation 408, the T-MN-DU receives the UE Context Modification Request signal, the DC Configured Indication signal, and the Available Mobility Configuration signal from the T- MN-CU. These signals received by the T-MN-DU enable the T-MN-DU to determine whether conditional LTM configuration, which would be used in case the target becomes the serving node, should be included in the UE context setup response (in the LTM CSI reporting configuration).

[0097] At operation 409, the T-MN-DU transmits a UE Context Setup Response signal to the T-MN-CU, and the T-MN-CU receives the UE Context Setup Response signal from the T-MN-DU.

[0098] At operation 410, in accordance with aspects of the present disclosure, the T-MN-CU transmits a HO Request Acknowledgment (Ack) signal and a SN Activated Indication signal (indicated as Aspect- lb), which indicates that a secondary node (SN) was activated, to the S-MN- CU. The S-MN-CU receives the HO Request Ack signal and the SN Activated Indication signal (Aspect- lb) from the T-MN-CU.

[0099] At operation 411, the S-MN-CU transmits a UE Context Modification Request signal, along with other signals, to the S-MN-DU. The UE Context Modification Request signal includes a channel state information (CSI) resource configuration request for LTM reporting configuration, and a list of candidate configuration identifiers.

[0100] In accordance with aspects of the present disclosure, at operation 411, the S-MN-CU also transmits a DC Configured Indication signal (indicated as Aspect- la) and an Available Mobility Configuration signal (indicated as Aspect-2a). As mentioned above, the DC Configured Indication signal indicates that DC has been configured. The Available Mobility Configuration signal contains a DC and conditional LTM Co-Existence Indication that is set to a value (e.g., bit value “00”) that indicates that DC and conditional LTM cannot be configured at the same time (e.g., for a target cell). The DC and conditional LTM Co-Existence Indication can have other values that indicate that DC and conditional LTM may be configured at the same time (e.g., for a target cell). At operation 411, the S-MN-DU receives the UE Context Modification Request signal, the DC Configured Indication signal, and the Available Mobility Configuration signal from the S- MN-CU.

[0101] At operation 412, and in accordance with aspects of the present disclosure, the S-MN- DU reads the DC Configured Indication (Aspect-la), which indicates that DC was configured (e.g., for a target cell), and reads the DC and Conditional Co-Existence Indication (Aspect- 2a), which was set to bit value “00,” indicating that DC and conditional LTM cannot be configured at the same time (e.g., for the target cell).

[0102] At operation 413, and in accordance with aspects of the present disclosure, based on the received the DC Configured Indication and the Available Mobility Configuration, the S-MN- DU determines that it cannot configure conditional LTM because DC and conditional LTM cannot be configured at the same time and DC has already been configured.

[0103] At operation 414, the S-MN-DU transmits a UE Context Modification Response signalwith channel state information (CSI) reporting configuration for conventional intra-CU LTM (e.g., intra-CU MCG LTM) to the S-MN-CU, and the S-MN-CU receives the UE Context Modification Response signal from the S-MN-DU.

[0104] The operations of FIG. 4 are merely illustrative, and variations are contemplated to be within the scope of the present disclosure. For example, in embodiments, the determination on whether conditional LTM can be configured is performed at the S-MN-CU, and then the S-MN- CU provides an indication to S-MN-DU on whether conditional LTM configuration is allowed. In such embodiments, the S-MN-DU can provide conditions for only the candidate cells where conditional LTM coexistence is allowed. Such embodiments can lead to hard prevention of configuration of conditional LTM if DC is configured at the candidate cell, or can be used to prevent DC if conditional LTM is already or would potentially be configured at the candidate cell.

[0105] In embodiments, the operations may include other operations not illustrated in FIG. 4. In embodiments, the operations may not include every operation illustrated in FIG. 4. In embodiments, the operations may be implemented in a different order than that illustrated in FIG. 4. In embodiments, the names of various signals and values may be different from what is described above. Such and other embodiments are contemplated to be within the scope of the present disclosure. Persons of skill in the art will appreciate that, although various example components are described as performing various functions, other components may perform those functions described in FIG. 4.

[0106] FIG. 5A and FIG. 5B is a flow diagram of a scenario involving inter-MN / inter-CU conditional LTM in which DC is prevented when conditional LTM is configured. In various embodiments, the components depicted in FIG. 5 may correspond to similar components described above in FIGS. 1 and 2. It will be understood that a described signal may have associated operations and a described operation may have associated signals.

[0107] In FIG. 5 A and FIG. 5B, the terms have the following meanings:S-MN-DU: source master-node DU T-MN-DU: target master-node DU S-MN-CU: source master- node CU T-MN-CU: target master-node CU SN-CU: secondary-node CU.

[0108] At operation 501, the UE is configured with single connectivity.

[0109] At operation 502 and 503, the UE reports L3 measurements to MN-S-CU via MN-S- DU, the MN-S-CU receives the L3 measurements from the UE via MN-S-DU.

[0110] At operation 504, the S-MN-CU decides to configure a target cell in T-MN-DU as preparation for inter-MN LTM. In embodiments, the S-MN-S-CU decides to configure a target PCell in T-MN-DU as preparation for the inter-MN MCG LTM. The MN-T-DU may prepare one or more cells, and cell2 and cell3 are illustrated examples of two cells that may be prepared.

[0111] At operation 505, and in accordance with aspects of the present disclosure, the S-MN- CU decides that it may configure conditional LTM for a candidate cell based on earlier radio link failures (RLF) or handover failures.

[0112] At operation 506, in accordance with aspects of the present disclosure, the S-MN-CU generates a Potential Conditional LTM Configuration Indication (indicated as Aspect-3a).

[0113] At operation 507, the S-MN-CU transmits a LTM handover (HO) Request signal, along with other signals, to the T-MN-CU.

[0114] In accordance with aspects of the present disclosure, at operation 507, the S-MN-CU also transmits the Potential Conditional LTM Configuration Indication (Aspect-3a), along with an Available Mobility Configuration (indicated as Aspect-3b), which contains a DC and Conditional Co-Existence Indication that is set to a value (e.g., bit value “00”) that indicates that DC and conditional LTM cannot be configured at the same time (e.g., for a target cell). The DC and conditional LTM Co-Existence Indication can have other values that indicate that DC and conditional LTM may be configured at the same time (e.g., for a target cell). At operation 507, the T-MN-CU receives the LTM HO Request signal, the Potential Conditional LTM Configuration Indication signal, and the Available Mobility Configuration signal from the S-MN-CU.

[0115] At operation 508, in accordance with aspects of the present disclosure, the T-MN-CU reads the Potential Conditional LTM Configuration Indication and the Available Mobility Configuration and determines that DC cannot be configured since conditional LTM is expected to be configured.

[0116] At operation 509, the T-MN-CU transmits a UE Context Set Up Request signal, along with other signals, to the T-MN-DU to prepare for LTM.

[0117] In accordance with aspects of the present disclosure, at operation 509, the S-MN-CU also transmits the Potential Conditional LTM Configuration Indication (Aspect-3a), along with an Available Mobility Configuration (indicated as Aspect-3b), which contains a DC and ConditionalCo-Existence Indication that is set to a value (e.g., bit value “00”) that indicates that DC and conditional LTM cannot be configured at the same time (e.g., for a target cell). The DC and conditional LTM Co-Existence Indication can have other values that indicate that DC and conditional LTM may be configured at the same time (e.g., for a target cell). At operation 507, the T-MN-CU receives the LTM HO Request signal, the Potential Conditional LTM Configuration Indication signal, and the Available Mobility Configuration signal from the S-MN-CU.

[0118] At operation 510, the T-MN-DU transmits a UE Context Setup Response signal to the T-MN-CU, and the T-MN-CU receives the UE Context Setup Response signal from the T-MN- DU.

[0119] At operation 511, the T-MN-CU transmits the HO Request Acknowledgment (Ack) signal to the S-MN-CU over Xn interface, and the S-MN-CU receives the HO Request Ack signal from the T-MN-CU.

[0120] At operation 512, the S-MN-CU transmits a UE Context Modification Request signal to the S-MN-DU, and the S-MN-DU receives the UE Context Modification Request signal from the S-MN-CU. The UE Context Modification Request signal includes a channel state information (CSI) resource configuration request for LTM reporting configuration, and a list of candidate configuration identifiers.

[0121] At operation 513, the S-MN-DU decides to configure conditional LTM, e.g., for cell edges where DU has observed radio link failures (RLF) or HO failures.

[0122] At operation 514, the S-MN-DU includes the LTM execution condition within the CSI reporting configuration. In embodiments, the S-MN-DU may prune the CSI measurement reporting configuration.

[0123] At operation 515, the S-MN-DU transmits a UE Context Modification Response signal with CSI reporting configuration for a selected candidate identifier to the S-MN-CU, and the S- MN-CU receives the UE Context Modification Response signal from the S-MN-DU.

[0124] At operation 516, in accordance with aspects of the present disclosure, the S-MN-CU transmits a Conditional LTM Prepared Indication signal (indicated as Aspect-3c) to the T-MN-CU over the Xn interface, and the T-MN-CU receives the Conditional LTM Prepared Indication signal from the S-MN-CU. The Conditional LTM Prepared Indication signal indicates that conditional LTM has been prepared.

[0125] At operation 517, the T-MN-CU forwards the Conditional LTM Prepared Indicationover the UE Context Modification Request to the T-MN-DU, and the T-MN-DU receives the Conditional LTM Prepared Indication over the UE Context Modification Request from the T-MN- CU.

[0126] At operation 518, the T-MN-DU is aware that conditional LTM is configured and may commence operation without receiving an explicit cell switch command.

[0127] At operation 519, the T-MN-DU transmits a UE Context Modification Response signal to the T-MN-CU, and the T-MN-CU receives the UE Context Modification Response signal from the T-MN-DU.

[0128] At operation 520, the T-MN-CU transmits the UE Context Modification Response signal to the S-MN-CU, and the S-MN-CU receives the UE Context Modification Response signal from the T-MN-CU.

[0129] At operation 521, the S-MN-CU generates CSI reporting configuration for conditional LTM to prepare the RRC Reconfiguration for the inter-CU conditional LTM (e.g., inter-CU MCG conditional LTM).

[0130] At operation 522, the S-MN-CU transmits the RRC Reconfiguration signal containing the CSI reporting configuration with execution condition linked to a candidate cell ID, to the UE, and the UE receives the RRC Reconfiguration signal from the S-MN-CU.

[0131] The operations of FIG. 5A and FIG. 5B are merely illustrative, and variations are contemplated to be within the scope of the present disclosure.

[0132] In embodiments, the operations may include other operations not illustrated in FIG. 5A and FIG. 5B. In embodiments, the operations may not include every operation illustrated in FIG. 5A and FIG. 5B. In embodiments, the operations may be implemented in a different order than that illustrated in FIG. 5A and FIG. 5B. In embodiments, the names of various signals and values may be different from what is described above. Such and other embodiments are contemplated to be within the scope of the present disclosure. Persons of skill in the art will appreciate that, although various example components are described as performing various functions, other components may perform those functions described in FIG. 5A and FIG. 5B.

[0133] Accordingly, FIG. 3-5B described various signals and operations relating to interworking of dual connectivity and conditional LTM both for intra-CU and inter-CU scenarios. Various aspects of particular signals were described above, including signals indicated as Aspect- la, Aspect-lb, Aspect-2a, Aspect-3a, Aspect-3b, and Aspect-3c among others. Such and othersignals will now be described below in more detail for various scenarios.

[0134] Generally, signalling to determine whether or not to prevent conditional LTM if DC is configured at the candidate cell or candidate MN both for intra-MN and inter-MN scenarios involve aspects Aspect- la, Aspect- lb, Aspect-2a, and Aspect- 2b. Signalling to determine whether or not to prevent configuration of dual connectivity at the candidate MN or candidate cell if conditional LTM is likely to be configured or is already configured for the MCG LTM cell switch, involves aspects Aspect-3a and Aspect-3b.

[0135] Aspect- la: Initially if DC is not configured and during the preparation phase if the candidate decides to configure dual connectivity and add a secondary node by transmitting SN addition Request, the source-CU will indicate the same to the source-DU with DC configured indication along with the UE Context Modification Request. The candidate specific DC configured indication may also contain a one-bit indication to indicate further whether the configured DC for the candidate cell is intra-CU or intra-CU.

[0136] Aspect- lb: In case of inter-MN scenario initially, if DC is not configured and during the preparation phase if the candidate decides to configure dual connectivity and add a secondary node by transmitting SN addition Request, the target MN-CU (T-MN-CU) must indicate to the source MN-CU (S-MN-CU) with SN activation indication along with the LTM HO Response over the Xn interface. The S-MN-CU upon receiving the SN activation indication is expected to generate the DC configured indication for the S-MN-DU transmit over UE Context Modification Request using Fl interface.

[0137] Aspect- 2a: In case if intra-CU or inter-CU LTM configured at the MN, if the source CU or target CU decides to configure dual connectivity at the candidate PCell, MN-S-CU generates Available Mobility Configuration which is included along with the UE Context Modification Request and sent to S-MN-DU. The Available Mobility Configuration contains the following Co-Existence fields, which may be fields indicating co-existence of (a) DC and conditional LTM, (b) DC and subsequent LTM, and / or (c) DC and subsequent conditional LTM. For each of these three scenarios (a) DC and conditional LTM, (b) DC and subsequent LTM, and / or (c) DC and subsequent conditional LTM, the Co-Existence Field can have three possible assigned values:If supported only for inter-CU: bit value “01”.If supported only for intra-CU: bit value “10”.If supported for both inter-CU and intra-CU: bit value “11”.Optionally, if only some of these fields are available, the source or the target MN can deduce by themselves which scenario is supported for, e.g., (1) DC and conditional LTM co-existence is supported for intra-CU LTM, and (2) DC and subsequent LTM co-existence is supported for intra- CU LTM, then it can be deduced that DC and subsequent conditional LTM co-existence is supported for intra-CU LTM.

[0138] Aspect- 2b: MN-S-DU reads the Available Mobility Configuration and checks the status of the co-existence status indicated within the Co-Existence fields inside the Available Mobility Configuration. If any one of the three Co-Existence fields are “enabled” indicated as bit values “01”, or “10” or “11” attributed to that scenario, the source CU infers that a specific coexistence scenario is valid either for the inter-CU or intra-CU case. If any of these fields is indicated to be “disabled” indicated as bit value “00” attributed to that scenario, it simply implies that the network cannot configure such co-existing features. For example, if DC is configured at the candidate cell as indicated over DC Configured Indication as per Aspect- la and DC and conditional LTM co-existence indication is set to bit value “00” or “disabled”, it means that DC has been configured at the candidate. Therefore, DC and conditional LTM cannot be configured at the same time, in that case S-MN-DU will prevent configuring conditional LTM.

[0139] Aspect-3a: In case of inter-CU LTM configured at the MN and DC is not configured initially, if the S-MN-CU decides that it may configure conditional LTM for the candidate PCell based on RLF or HO failure detected earlier at the cell edges, it will transmit a Potential Conditional LTM Configuration Indication along with the LTM HO Request to the target MN-CU (T-MN-CU) over the Xn interface.

[0140] Aspect-3b: In case if inter-CU LTM configured at the MN and DC is not configured initially, the S-MN-CU will transmit the Available Mobility Configuration which is included along with the LTM HO Request sent to T-MN-CU. The Available Mobility Configuration contains the scenario Co-Existence fields as indicated in Aspect-2a. T-MN-CU upon reception of the Potential Conditional LTM Configuration indication and Available Mobility Configuration can decide if it can continue to configure DC for the candidate like the way described in Aspect-2b.

[0141] Aspect-3 c: If conditional LTM is configured for the candidate, the S-MN-CU indicates this decision to the T-MN-CU over a signalling Conditional LTM Prepared Indication which indicated that conditional LTM has been configured for the candidate cell by the MN. Based onthe reception of the Conditional LTM Prepared indication by the T-MN-CU, it can indicate the T- MN-DU over UE Context Modification Request that conditional LTM has been configured and it may commence operation without cell switch notification. Alternatively, the Available Mobility Configuration can be indicated to the T-MN-CU by the S-MN-CU after the S-MN-CU has decided to configure conditional-LTM for the candidate cell and indicate the same along with Conditional LTM Prepared Indication

[0142] Aspect-4a: The determination on whether conditional LTM can be configured is done at the MN-S-CU and then it provides an indication to MN-S-DU on whether conditional LTM configuration is allowed. Then, MN-S-DU can only provide conditions for the candidates where conditional LTM co-existence is allowed. This approach can lead to hard prevention of configuration of conditional LTM if DC is configured at the candidate cell. Similarly, this can prevent DC if conditional LTM is already or would potentially be configured at the candidate cell.

[0143] FIG. 6 is a diagram of an example block diagram of components of an apparatus, according to one illustrated aspect of the present disclosure

[0144] Referring now to FIG. 6, there is shown a block diagram of example components of a user equipment apparatus or a network node apparatus. The apparatus includes an electronic storage 610, a processor 620, a network interface 630, and a memory 640. The various components may be communicatively coupled with each other. The processor 620 may be and may include any type of processor, such as a single-core central processing unit (CPU), a multi-core CPU, a microprocessor, a digital signal processor (DSP), a System- on- Chip (SoC), or any other type of processor. The memory 640 may be a volatile type of memory, e.g., RAM, or a non-volatile type of memory, e.g., NAND flash memory. The memory 640 includes processor-readable instructions that are executable by the processor 620 to cause the apparatus to perform various operations, including the operations mentioned above herein.

[0145] The electronic storage 610 may be and include any type of electronic storage used for storing data, such as hard disk drive, solid state drive, and / or optical disc, among other types of electronic storage. The electronic storage 610 stores processor- readable instructions for causing the apparatus to perform its operations and stores data associated with such operations, such as storing data relating to 5G NR standards, among other data, such as any of the data described above herein. The network interface 630 may implement wireless networking technologies such as LTE, 5G NR, 5G Advance, Wi-Fi 6, and / or other wireless networking technologies.

[0146] The components shown in FIG. 6 are merely examples, and persons skilled in the art will understand that an apparatus includes other components not illustrated and may include multiples of any of the illustrated components. Such and other embodiments are contemplated to be within the scope of the present disclosure.

[0147] Further embodiments of the present disclosure include the following examples. In various examples, the disclosed “means” for performing an operation may include processor- readable instructions, at least one processor capable of executing the processor-readable instructions, and / or at least one memory capable of storing the processor-readable instructions.

[0148] Example 1.1. An apparatus, comprising: means for receiving one of: an indication that dual connectivity is configured, or an indication of potential conditional Layer- 1 / Layer-2 triggered mobility (LTM) configuration; means for reading a configurable value indicating that co-existence between dual connectivity and conditional LTM is not permitted; means for, in case of receiving the indication that dual connectivity is configured, determining that conditional LTM cannot be configured; and means for, in case of receiving the indication of potential conditional LTM configuration, determining that dual connectivity cannot be configured for a candidate cell.

[0149] Example 1.2. The apparatus of Example 1.1, wherein the indication that dual connectivity is configured indicates whether the configured dual connectivity for a candidate cell is for an intra-centralized-unit candidate cell or for an inter-centralized unit candidate cell.

[0150] Example 1.3. The apparatus of any one of the preceding Examples, wherein the configurable value indicates co-existence between dual connectivity and subsequent conditional LTM.

[0151] Example 1.4. The apparatus of any one of the preceding Examples, further comprising: means for reading a configurable value indicating that co-existence between dual connectivity and subsequent LTM is not permitted.

[0152] Example 1.5. The apparatus of any one of the preceding Examples, wherein the configurable value is further configurable to indicate one of: co-existence between dual connectivity and conditional LTM is only permitted for inter-centralized unit candidate cells,co-existence between dual connectivity and conditional LTM is only permitted for intra-centralized unit candidate cells, or co-existence between dual connectivity and conditional LTM is permitted for intracentralized unit or inter-centralized unit candidate cells.

[0153] Example 1.6. The apparatus of Example 1.1, wherein the indication that dual connectivity is configured and the configurable value indicating that co-existence between dual connectivity and conditional LTM is not permitted, are transmitted by a source centralized unit of a master node (MN-S-CU) and are received by a source distributed unit of the master node (MN- S-DU).

[0154] Example 1.7. The apparatus of Example 1.1, wherein the indication that dual connectivity is configured and the configurable value indicating that co-existence between dual connectivity and conditional LTM is not permitted, are transmitted by a centralized unit of a source master-node (S-MN-CU) and are received by a distributed unit of the source master-node (S-MN- DU).

[0155] Example 1.8. The apparatus of Example 1.7, wherein the indication that dual connectivity is configured is transmitted by the S-MN-CU based on the S-MN-CU receiving an indication that a secondary node was activated.

[0156] Example 1.9. The apparatus of Example 1.8, wherein the indication that a secondary node was activated is transmitted by a centralized unit of a target master-node (T-MN- CU).

[0157] Example 1.10. The apparatus of Example 1.1, wherein the indication of potential conditional LTM configuration and the configurable value indicating that co-existence between dual connectivity and conditional LTM is not permitted, are transmitted by a centralized unit of a source master-node (S-MN-CU) and are received by a centralized unit of a target master-node (T- MN-CU).

[0158] Example 1.11. The apparatus of Example 1.10, wherein the S-MN-CU decides to possibly request a distributed unit of the source master-node (S-MN-DU) to configure conditional LTM, wherein the S-MN-CU generates the indication of potential conditional LTM configuration based on the decision.

[0159] Example 1.12. The apparatus of Example 1.10, further comprising receiving, by theT-MN-CU, from the S-MN-CU, an indication that conditional LTM was prepared.

[0160] Example 1.13. A apparatus comprising: means for receiving, by a first apparatus from a second apparatus, for a Layer- 1 / Lay er- 2 triggered mobility (LTM) candidate cell, one of: an indication that conditional LTM configuration is not permitted, or an indication that dual connectivity is not permitted; means for, in case of receiving the indication that conditional LTM configuration is not permitted, determining that conditional LTM cannot be configured and transmitting, by the first apparatus toward the second apparatus, a user equipment configuration not comprising conditional LTM configuration; and means for, in case of receiving the indication that dual connectivity is not permitted, determining that dual connectivity cannot be configured and transmitting, by the first apparatus toward the second apparatus, a user equipment configuration not comprising dual connectivity configuration.

[0161] Example 1.14. The apparatus of Example 1.13, further comprising: means for determining, by the first apparatus, that co-existence between dual connectivity and conditional LTM is not permitted based on at least one of: a preconfigured rule indicating that co-existence between dual connectivity and conditional LTM is not permitted, or a value, received from the second apparatus, indicating that co-existence between dual connectivity and conditional LTM is not permitted.

[0162] The embodiments and aspects disclosed herein are examples of the present disclosure and may be embodied in various forms. Lor instance, although certain embodiments herein are described as separate embodiments, each of the embodiments herein may be combined with one or more of the other embodiments herein. Specific structural and functional details disclosed herein are not to be interpreted as limiting, but as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present disclosure in virtually any appropriately detailed structure. Like reference numerals may refer to similar or identical elements throughout the description of the figures.

[0163] Although in various embodiments, protocols such as 5G protocols may be described, persons of skill in the art will understand that other protocols (e.g., 6G protocols) may be utilizedfor any of the operations and / or signaling described above along with their associated data, IES, messaging, or the like.

[0164] The phrases “in an aspect,” “in aspects,” “in various aspects,” “in some aspects,” or “in other aspects” may each refer to one or more of the same or different aspects in accordance with this present disclosure. The phrase “a plurality of’ may refer to two or more.

[0165] In various embodiments, the terms “first message” and “second message”, as well as any subsequent messages may refer to any messages that are transmitted or received in an order and are not necessarily limited to any particular message.

[0166] The phrases “in an embodiment,” “in embodiments,” “in various embodiments,” “in some embodiments,” or “in other embodiments” may each refer to one or more of the same or different embodiments in accordance with the present disclosure. A phrase in the form “A or B” means “(A), (B), or (A and B).” A phrase in the form “at least one of A, B, or C” means “(A); (B); (C); (A and B); (A and C); (B and C); or (A, B, and C) ”

[0167] Any of the herein described methods, programs, algorithms or codes may be converted to, or expressed in, a programming language or computer program. The terms “programming language” and “computer program,” as used herein, each include any language used to specify instructions to a computer, and include (but is not limited to) the following languages and their derivatives: Assembler, Basic, Batch files, BCPL, C, C+, C++, Delphi, Fortran, Java, JavaScript, machine code, operating system command languages, Pascal, Perl, PL1, Python, scripting languages, Visual Basic, metalanguages which themselves specify programs, and all first, second, third, fourth, fifth, or further generation computer languages. Also included are database and other data schemas, and any other meta- languages. No distinction is made between languages which are interpreted, compiled, or use both compiled and interpreted approaches. No distinction is made between compiled and source versions of a program. Thus, reference to a program, where the programming language could exist in more than one state (such as source, compiled, object, or linked) is a reference to any and all such states. Reference to a program may encompass the actual instructions and / or the intent of those instructions.

[0168] While aspects of the present disclosure have been shown in the drawings, it is not intended that the present disclosure be limited thereto, as it is intended that the present disclosure be as broad in scope as the art will allow and that the specification be read likewise. Therefore, the above description should not be construed as limiting, but merely as exemplifications of particularaspects. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.

Claims

We Claim:

1. A method comprising: receiving one of: an indication that dual connectivity is configured, or an indication of potential conditional Layer- 1 / Layer-2 triggered mobility (LTM) configuration; reading a configurable value indicating that co-existence between dual connectivity and conditional LTM is not permitted; in case of receiving the indication that dual connectivity is configured, determining that conditional LTM cannot be configured; and in case of receiving the indication of potential conditional LTM configuration, determining that dual connectivity cannot be configured for a candidate cell.

2. The method of claim 1, wherein the indication that dual connectivity is configured indicates whether the configured dual connectivity for a candidate cell is for an intra-centralized- unit candidate cell or for an inter-centralized unit candidate cell.

3. The method of any one of the preceding claims, wherein the configurable value indicates co-existence between dual connectivity and subsequent conditional LTM.

4. The method of any one of the preceding claims, further comprising reading a configurable value indicating that co-existence between dual connectivity and subsequent LTM is not permitted.

5. The method of any one of the preceding claims, wherein the configurable value is further configurable to indicate one of: co-existence between dual connectivity and conditional LTM is only permitted for intercentralized unit candidate cells, co-existence between dual connectivity and conditional LTM is only permitted for intracentralized unit candidate cells, or co-existence between dual connectivity and conditional LTM is permitted for intracentralized unit or inter-centralized unit candidate cells.

6. The method of claim 1, wherein the indication that dual connectivity is configured and the configurable value indicating that co-existence between dual connectivity and conditional LTM is not permitted, are transmitted by a source centralized unit of a master node (MN-S-CU) and are received by a source distributed unit of the master node (MN-S-DU).

7. The method of claim 1, wherein the indication that dual connectivity is configured and the configurable value indicating that co-existence between dual connectivity and conditional LTM is not permitted, are transmitted by a centralized unit of a source master-node (S-MN-CU) and are received by a distributed unit of the source master-node (S-MN-DU).

8. The method of claim 7, wherein the indication that dual connectivity is configured is transmitted by the S-MN-CU based on the S-MN-CU receiving an indication that a secondary node was activated.

9. The method of claim 8, wherein the indication that a secondary node was activated is transmitted by a centralized unit of a target master-node (T-MN-CU).

10. The method of claim 1 , wherein the indication of potential conditional LTM configuration and the configurable value indicating that co-existence between dual connectivity and conditional LTM is not permitted, are transmitted by a centralized unit of a source masternode (S-MN-CU) and are received by a centralized unit of a target master-node (T-MN-CU).

11. The method of claim 10, wherein the S-MN-CU decides to possibly request a distributed unit of the source master-node (S-MN-DU) to configure conditional LTM, wherein the S-MN-CU generates the indication of potential conditional LTM configuration based on the decision.

12. The method of claim 10, further comprising receiving, by the T-MN-CU, from the S-MN-CU, an indication that conditional LTM was prepared.

13. A method comprising: receiving, by a first apparatus from a second apparatus, for a Layer- 1 / Layer-2 triggered mobility (LTM) candidate cell, one of: an indication that conditional LTM configuration is not permitted, or an indication that dual connectivity is not permitted; in case of receiving the indication that conditional LTM configuration is not permitted, determining that conditional LTM cannot be configured and transmitting, by the first apparatus toward the second apparatus, a user equipment configuration not comprising conditional LTM configuration; and in case of receiving the indication that dual connectivity is not permitted, determining that dual connectivity cannot be configured and transmitting, by the first apparatus toward the second apparatus, a user equipment configuration not comprising dual connectivity configuration.

14. The method of claim 13, further comprising: determining, by the first apparatus, that co-existence between dual connectivity and conditional LTM is not permitted based on at least one of: a preconfigured rule indicating that co-existence between dual connectivity and conditional LTM is not permitted, or a value, received from the second apparatus, indicating that co-existence between dual connectivity and conditional LTM is not permitted.

15. An apparatus comprising: at least one processor; and at least one memory having stored thereon instructions which, when executed by the at least one processor, cause the apparatus at least to perform a method as in any one of claims 1- 14.

16. A non-transitory processor-readable medium having stored thereon instructions which, when executed by at least one processor of an apparatus, causes the apparatus at least to perform a method as in any one of claims 1-14.

Images