WO2025230554A1

WO2025230554A1 - Co-ordination between master cell group (mcg) and secondary cell group (scg)

Info

Publication number: WO2025230554A1
Application number: PCT/US2024/037053
Authority: WO
Inventors: Subramanya CHANDRASHEKAR; Vihang KAMBLE
Original assignee: Rakuten Symphony Inc; Rakuten Mobile USA LLC
Current assignee: Rakuten Symphony Inc; Rakuten Mobile USA LLC
Priority date: 2024-04-30
Filing date: 2024-07-08
Publication date: 2025-11-06
Anticipated expiration: 2026-10-30

Abstract

Embodiments of the present disclosure disclose co-ordination between Master Cell Group (MCG) and Secondary Cell Group (SCG). The method comprises transmitting during a dual connectivity setup procedure for a User Equipment (UE), a Layer1/Layer2 Triggered Mobility (LTM) indicator indicating current configuration state of LTM in a Master Node (MN) to a Secondary node (SN), through a Secondary Node (S-Node) addition request, to activate a Dual Connectivity (DC) configuration in UE; and performing one of transmitting upon activating the DC configuration in the UE, subsequently, an updated configuration state of LTM in the MN through a Next-Generation Radio Access Network (NG-RAN) node configuration update upon occurrence of an event or receiving upon activating the DC configuration in the UE, subsequently, an updated configuration state of LTM in the SN through the NG-RAN node configuration update upon occurrence of the event.

Description

CO-ORDINATION BETWEEN MASTER CELL GROUP (MCG) AND SECONDARY CELL GROUP (SCG)

FIELD

[0001] The present disclosure relates to co-ordination between Master Cell Group (MCG) and Secondary Cell Group (SCG).

BACKGROUND

[0002] In 3GPP, a disaggregated architecture of gNodeB (gNB) is defined as decomposing the gNB into multiple logical entities. The gNB is split into three logical nodes i.e., Central Unit (CU), Distributed Unit (DU), and Radio Unit (RU). A single DU may host multiple cells. For instance, the 3GPPP defines that a DU can host up to 512 cells. The CU (also referred as gNB- CU) hosts upper layers such as Packet Data Convergence Protocol (PDCP) and Radio Resource Control (RRC) layers, while the DU (also referred as gNB-DU) hosts lower layers such as Radio Link Control (RLC), Media Access Control (MAC), and Physical (PHY) layers. The scheduling operation takes place at the gNB-DU.

[0003] A handover mechanism is a process in mobile communication in which cellular transmission is transferred from one cell to another neighbouring cell of a network without losing connectivity to the cellular transmission. In other words, the handover (mobility) is a process of transferring an ongoing communication session of a User Equipment (UE) from one cell (i.e., base station or gNodeB (gNB)) to another cell. A Lower-layer Triggered mobility (LTM) or L1/L2 based mobility was introduced in Release 18 of Third Generation Partnership Project (3GPP). LTM enables a serving cell change via L1/L2 signaling, while maintaining configuration of upper layers and/or minimizing changes of configuration of the lower layers. The LTM provides improvements in handover latency and interruption time compared to Layer 3 based mobility. However, LTM as introduced in Release 18 has limited scope. The Release 19 work item of 3GPP aims to extend the scope and cover the remaining scenarios like dual connectivity and inter gNB-CU use-cases with LTM.

[0004] The information disclosed in this background section is only for enhancement of understanding of the general background of the disclosure and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.

SUMMARY

[0005] In an embodiment, the present disclosure discloses a method. The method comprises transmitting during a dual connectivity setup procedure for a User Equipment (UE), a Layerl/Layer2 Triggered Mobility (LTM) indicator indicating current configuration state of LTM in a Master Node (MN) to a Secondary node (SN), through a Secondary Node (S-Node) addition request, to activate a Dual Connectivity (DC) configuration in the UE. Further, the method comprises performing one of, transmitting upon activating the DC configuration in the UE, subsequently, an updated configuration state of LTM in the MN through a Next- Generation Radio Access Network (NG-RAN) node configuration update upon occurrence of an event or receiving upon activating the DC configuration in the UE, subsequently, an updated configuration state of LTM in the SN through the NG-RAN node configuration update upon occurrence of the event.

[0006] In an embodiment, the present disclosure discloses a method. The method comprises receiving during a dual connectivity setup procedure for a User Equipment (UE), a Layerl/Layer2 Triggered Mobility (LTM) indicator indicating current configuration state of LTM in a Master Node (MN) through a Secondary Node (S-Node) addition request, to activate a Dual Connectivity (DC) configuration in the UE. Further, the method comprises performing one of, transmitting upon activating the DC configuration in the UE, subsequently, an updated configuration state of LTM in a Secondary Node (SN) through a Next-Generation Radio Access Network (NG-RAN) node configuration update upon occurrence of an event or receiving upon activating the DC configuration in the UE, subsequently an updated configuration state of LTM in the MN through the NG-RAN node configuration update upon occurrence of the event.

[0007] In an embodiment, the present disclosure discloses a Master Node (MN). The MN is configured to transmit during a dual connectivity setup procedure for a User Equipment (UE), a Layerl/Layer2 Triggered Mobility (LTM) indicator indicating current configuration state of LTM in a Master Node (MN) to a Secondary node (SN), through a Secondary Node (S-Node) addition request, to activate a Dual Connectivity (DC) configuration in a User Equipment (UE). Further, the MN is configured to perform one of, transmit upon activating the DC configuration in the UE, subsequently, an updated configuration state of LTM in the MN through a Next- Generation Radio Access Network (NG-RAN) node configuration update upon occurrence of an event or receive upon activating the DC configuration in the UE, subsequently, an updated configuration state of LTM in the SN through the NG-RAN node configuration update upon occurrence of the event.

[0008] In an embodiment, the present disclosure discloses a Secondary Node (SN). The SN is configured to receive during a dual connectivity setup procedure for a User Equipment (UE), a Layerl/Layer2 Triggered Mobility (LTM) indicator indicating current configuration state of LTM in a Master Node (MN) through a Secondary Node (S-Node) addition request, to activate a Dual Connectivity (DC) configuration in a User Equipment (UE). Further, the SN is configured to perform one of, transmit upon activating the DC configuration in the UE, subsequently, an updated configuration state of LTM in a Secondary Node (SN) through a Next-Generation Radio Access Network (NG-RAN) node configuration update upon occurrence of an event or receive upon activating the DC configuration in the UE, subsequently an updated configuration state of LTM in the MN through the NG-RAN node configuration update upon occurrence of the event.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Features, aspects, and advantages of embodiments of the disclosure will be described below with reference to the accompanying drawings, in which like reference numerals denote like elements, and wherein:

[0010] FIG. 1A illustrates a conventional disaggregated gNodeB (gNB) architecture;

[0011] FIG. IB shows an exemplary architecture illustrating co-ordination between Master Cell Group (MCG) and Secondary Cell Group (SCG), in accordance with some embodiments of the present disclosure;

[0012] FIG. 2A illustrates a detailed diagram of a Master Node (MN), in accordance with some embodiments of the present disclosure;

[0013] FIG.S 3A-3E illustrate exemplary flow charts illustrating method steps for coordination between Master Cell Group (MCG) and Secondary Cell Group (SCG), in accordance with some embodiments of the present disclosure; [0014] FIG. 4A shows a flowchart illustrating a method for co-ordination between Master Cell Group (MCG) and Secondary Cell Group (SCG) by a Master Node (MN), in accordance with some embodiments of the present disclosure;

[0015] FIG. 4B shows a flowchart illustrating a method for co-ordination between Master Cell Group (MCG) and Secondary Cell Group (SCG) by a Secondary Node (SN), in accordance with some embodiments of the present disclosure; and

[0016] FIG. 5 shows a diagram of example components of a gNodeB -Control Unit (gNB-CU) for performing LTM recovery procedure, in accordance with embodiments of the present disclosure.

DETAILED DESCRIPTION

[0017] The following detailed description of example embodiments refers to the accompanying drawings. The foregoing disclosure provides illustration and description, but is not intended to be exhaustive or to limit the implementations to the precise form disclosed. Modifications and variations are possible in light of the above disclosure or may be acquired from practice of the implementations. Further, 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). Additionally, the flowchart and description of operations provided below relate to one of the various embodiments. It should be noted that it is possible to make other embodiments that do not exactly match the flowchart and its description. It is understood that in other embodiments one or more operations may be omitted, one or more operations may be added, one or more operations may be performed simultaneously (at least in part).

[0018] It will be apparent that systems and/or methods, described herein, may be implemented in different forms of hardware, software, or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and/or methods is not limiting of the implementations. Thus, 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 may be designed to implement the systems and/or methods based on the description herein. [0019] Even though particular combinations of features are recited in the claims and/or disclosed in the specification, these combinations are not intended to limit the disclosure of implementations. In fact, many of these features may be combined in ways not specifically recited in the claims and/or disclosed in the specification. Although each dependent claim listed below may directly depend on only one claim, the disclosure of implementations includes each dependent claim in combination with every other claim in the claim set.

[0020] No element, act, or instruction used herein 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.” Also, as used herein, the terms “has,” “have,” “having,” “include,” “including,” or the like are intended to be open-ended terms. Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Furthermore, expressions such as “at least one of [A] and [B] ,” “[A] and/or [B],” or “at least one of [A] or [B]” are to be understood as including only A, only B, or both A and B.

[0021] The foregoing disclosure provides illustration and description but is not intended to be exhaustive or to limit the implementations to the precise form disclosed. Modifications and variations are possible in light of the above disclosure or may be acquired from practice of the implementations.

[0022] Layerl/Layer2 Triggered mobility (LTM) introduced in Release 18 of Third Generation Partnership (3GPP) project enables a serving cell change via L1/L2 signaling, while maintaining configuration of upper layers and/or minimizing changes of configuration of the lower layers. However, LTM as introduced in Release 18 has several scope limitations compared to Layer 3 mobility scope. The Release 19 work item of 3GPP aims to eliminate these limitations.

[0023] In 3GPP, a disaggregated architecture of gNodeB (gNB) is defined as decomposing the gNB into multiple logical entities, as shown in FIG. 1A. The gNB is split into three logical nodes i.e., Central Unit (CU) (also referred as gNB-CU), Distributed Unit (DU) (also referred as gNB-DU), and Radio Unit (RU). In order to support L1/L2 centric inter-cell change (i.e. change of serving cell)/LTM in the disaggregated gNB architecture, a new mechanism is needed in which configuration takes place at the gNB-CU, but executed autonomously by the gNB-DU without further interaction with upper layers. [0024] The objectives of Release 19 of 3GPP includes:

Specify support for inter-CU Layer 2 Mobility (LTM) [RAN2, RAN 3] o Prioritize the case when CU is acting as MN when DC is not configured o As secondary priority, support the case when NR-DC is configured and CU is acting as SN and MCG is unchanged o As secondary priority, support the case when NR-DC is configured, CU is acting as MN and SCG is unchanged or SCG is released

■ Note: The case that LTM is configured in both MCG and SCG is excluded o Specify support for subsequent LTM mobility procedures aiming to avoid RRC configuration between cell switches as per Rel- 18 LTM

■ Coordination with SAS needed with respect to security- key handling o Rel. 18 intra-CU LTM procedure is considered as baseline for adding inter-CU support Measurements related enhancements for purpose of supporting LTM: [RAN2, RANI ] o Measurement related enhancements are applicable to Intra-CU MCG/SCG LTM and Inter-CU MCG/SCG LTM o Specify necessary components to support event triggered LI measurement reporting [RAN2, RANI ]

■ RANI and RAN2 to progress independently on the event triggered measurements objectives of their respective MIMO and Mobility enhancement WIs. Review progress at RAN#105 to see if any modification of objectives is required to avoid/manage any overlap in the work o Specify support for CSI-RS measurements for LTM procedures and enable CSI-RS based beam management, and/or other necessary physical layer operations on candidate cells before LTM [RANI ]

Specify support of conditional LTM [RAN2, RAN 3, RANI ] o Prioritize intra-CU LTM o Checkpoint to review objective at RAN#105. RAN WG work to not start before this checkpoint

Specify’ RRM requirements related to the above objectives as necessary [RAN4]

[0025] In Release 18, LTM was limited to intra-CU and single connectivity. In Release 19, LTM support for New Radio- Dual Connectivity (NR-DC) is included as shown in the abovestated objectives of Release 19. The gNB is divided into multiple distributed units and central units. The distributed units host MCG and SCG separately. Also, the central units host MN and SN separately.

[0026] In both Release 18 and Release 19, simultaneous LTM at Primary Cell (PCell) and Primary Secondary Cell (PSCell) isn’t permitted. LTM is configured independently at MCG and SCG. Whichever cell group configures LTM first will have access to the feature. This also means that if LTM is configured at MCG (for example after or even before DC is configured), LTM cannot be configured at SCG. However, hypothetically if the LTM was configured in SCG as well, this would lead to resource wastage as the LTM was already configured in MCG. As the resource reservation/LTM candidate cell preparation is not started without awareness of the other cell group status. This causes unnecessary overhead and wastage of resources. Therefore, a well-coordinated mechanism to ensure LTM configuration is consistent is required to avoid resource wastage.

[0027] The present disclosure provides methods and apparatuses to perform co-ordination between Master Cell Group (MCG) and Secondary Cell Group (SCG). According to the present disclosure, during a dual connectivity setup procedure for a User Equipment (UE), a Master Node (MN) transmits a Layerl/Layer2 Triggered Mobility (LTM) indicator indicating current configuration state of LTM in a Master Node (MN) to a Secondary node (SN), through a Secondary Node (S-Node) addition request, to activate a Dual Connectivity (DC) configuration in the UE. As the UE is establishing DC, i.e., connection with Secondary Node (SN) is also established, the SN receives the LTM indicator indicating current configuration state of LTM in the MN. Further, according to the present disclosure, the MN may transmit upon activating the DC configuration in the UE, subsequently, an updated configuration state of LTM in the MN through a Next-Generation Radio Access Network (NG-RAN) node configuration update (or a similar procedure) upon occurrence of an event. The event may include, but not limited to, configuration of LTM in in node currently connected with the UE, change in MN, change in SN, handover of the UE to a node which support LTM and handover of the UE to a node which does not support LTM. The SN receives upon activating the DC configuration in the UE, subsequently an updated configuration state of LTM in the MN through the NG-RAN node configuration update upon occurrence of the event. Similarly, the SN may transmit upon activating the DC configuration in the UE, subsequently, an updated configuration state of LTM in the SN through the NG-RAN node configuration update upon occurrence of an event. In this case, the MN receives upon activating the DC configuration in the UE, subsequently, an updated configuration state of LTM in the SN through the NG-RAN node configuration update upon occurrence of the event. This helps in ensuring consistent LTM configurations which helps in avoiding resource wastage and overhead as there is a well-coordinated mechanism between the MN and SN while performing LTM configuration due to occurrence of the event such as change in MN, change in SN and handover of the UE.

[0028] FIG. 1A illustrates a conventional disaggregated gNodeB (gNB) architecture. In Fifth Generation (5G) networks, a base station or a gNB is split into three distinct components i.e., a Centralized Unit (CU) (also referred as the gNB-CU in the description), a Distributed Unit (DU) (also referred as the gNB-DU in the description), and a Remote Radio Unit (RU) (not illustrated in FIG.s). The gNB-CU serves as central intelligence, adeptly handling complex and centralized network functions. These functions include, but are not limited to, proficient radio resource management, effective network control, and seamless coordination with the 5GC. The gNB-DU is responsible for managing data plane processing, encompassing vital tasks such as data transmission and reception with a User Equipment (UE) (not illustrated in FIG. 1 A). The gNB-DU interfaces seamlessly with the gNB-CU over Fl interface. FIG. 1 A further illustrates a separation of control-plane and user-plane for the gNB-CU (i.e., gNB-CU-CP and gNB-CU- UP). The gNB-CU-CP is connected to the gNB-DU through Fl-C interface. The gNB-CU-UP is connected to the gNB-DU through FLU interface. The gNB-CU-CP is connected to gNB- CU-CP^) over El interface. The RU deals with physical layer functions, housing antennas and radio transceivers that facilitate the actual transmission and reception of radio signals. The description of the present disclosure is explained considering Fifth Generation (5G) networks only. However, the present disclosure is applicable to any type of networks such as Fourth Generation (4G) networks, 6G networks, and the like.

[0029] FIG. IB shows an exemplary architecture illustrating co-ordination between Master Cell Group (MCG) and Secondary Cell Group (SCG), in accordance with some embodiments of the present disclosure.

[0030] Exemplary architecture 100 illustrates a gNodeB (gNB) is divided into multiple Distributed Units i.e. gNB-DUl 103i and gNB-DU2 103₂ connected to multiple Central Units gNB-CUl 1011 and gNB-CU2 1011. The gNB-DUl 103i and gNB-DU2 103₂ host Master Cell Group (MCG) and Secondary Cell Group (SCG) separately. Also, the gNB-CUl 1011 and gNB-CU2 101₂ host MN and SN separately. In an embodiment, the gNB-CUl 1011 hosts the MN and the gNB-CU2 101₂ hosts the SN. In some embodiments, the gNB-CU2 1011 may host the SN and the gNB-CU2 101₂ may host the SN (not shown in FIG.). The role of gNB-CU may change based on network requirements. In an embodiment, User Equipment (UE) 105 communicates with the gNB-CUl 1011 and gNB-CU2 1012 via the gNB-DUl 103i and the gNB-DU2 1032, over the Fl interface. The gNB-CUl 1011 and gNB-CU2 IOI2 may be collectively referred as gNB-CU 101. The UE 105 represents end-user devices that access services and applications through the wireless network. The UE 105 is configured to connect to the central units and the distributed units over the wireless network. As an example, the UE 105 may be, without limitation, any device used by a user to communicate over the wireless network, such as, but not limited to, mobile phones, smartphones, laptops, wearables, Internet of Things (loTs), and the like. The gNB-CUl 1011 and gNB-CU2 IOI2 communicate over Xn interface. The present disclosure is explained with respect to NR-DC. However, this should not be considered as limiting. The present disclosure is applicable to any other dual connectivity system. Hereafter, the gNB-CUl 1011 is referred as a Master Node (MN). The gNB-CU2 IOI2 is referred as a Secondary Node (SN).

[0031] In an embodiment, the MN may be configured to transmit during a Dual Connectivity (DC) setup procedure for the UE 105, a Layerl/Layer2 Triggered Mobility (LTM) indicator indicating current configuration state of LTM in the MN to the SN, through a Secondary Node (S-Node) addition request, to activate a DC configuration in the UE 105. In an embodiment, the UE 105 may be configured with Single Connectivity (SC) and then Dual Connectivity (DC). In some embodiments, the UE 105 may be configured with DC directly when establishing connection with telecommunication network. In an embodiment, the LTM indicator may be a parameter in the S-Node addition request and the NG-RAN node configuration update or a similar procedure over Xn. As an example, the S-Node addition request may be “S-NODE ADDITION REQUEST (MN_LTM_0N)“, here “MN_LTM_0N” is an exemplary value of LTM indicator which indicates that the LTM is configured in MN. The current configuration state may include, without limitation, one of, LTM ON in MN, LTM OFF in MN, LTM ON in SN, LTM OFF in SN or LTM OFF in BOTH MN and SN. The LTM_OFF in BOTH MN and SN is a default configuration state. The SN may be configured to receive the indicator indicating current configuration state of LTM in the MN. The LTM indicator helps in coordination between the MN and SN as the cell preparation is started in either MN or SN based on the value of LTM indicator indicating current status.

[0032] In an embodiment, upon transmitting the LTM indicator to the SN, the MN may be configured to transmit upon activating the DC configuration in the UE 105, subsequently, an updated configuration state of LTM in the MN through a Next-Generation Radio Access Network (NG-RAN) node configuration update upon occurrence of an event. As an example, the NG-RAN node configuration update may be “NG-RAN NODE CONFIGURATION UPDATE (MN_LTM_ON)”. The event may include, without limitation, at least one of, configuration of LTM in node currently connected with the UE 105, change in MN, change in SN, handover of the UE 105 to a node which support LTM and handover of the UE 105 to a node which does not support LTM. The updated configuration state may include, without limitation, one of, LTM ON in MN (interchangeably represented as MN_LTM_0N), LTM OFF in MN (interchangeably represented as MN_LTM_OFF), LTM ON in SN (interchangeably represented as SN_LTM_ON), LTM OFF in SN (interchangeably represented as SN_LTM_OFF) or LTM OFF in BOTH MN and SN. The LTM_OFF in BOTH MN and SN is a default configuration state which indicates that the LTM is OFF in MN and SN. In an embodiment, when the MN transmits the updated configuration state of LTM in the MN to the SN, the SN receives subsequently an updated configuration state of LTM in the MN through the NG-RAN node configuration update upon occurrence of the event. The MN may transmit the LTM indicator indicating the current configuration state “LTM ON in MN” through the S- Node addition request to the SN, when the LTM is configured in the MN before activation of the DC configuration in the UE 105. The LTM indicator is included in the S-Node addition request as LTM is configured in the UE 105 before activation of the DC configuration in the UE 105. When the LTM is configured in the MN after activation of the DC configuration in the UE 105, the MN may transmit the LTM indicator indicating the updated configuration state “LTM ON in MN” through the NG-RAN node configuration update to the SN. The SN may receive the LTM indicator indicating the updated configuration state “LTM ON in MN” through the NG-RAN node configuration update to the SN, when the LTM is configured in the SN after activation of the DC configuration in the UE 105. Similarly, the MN may transmit the LTM indicator indicating the updated configuration state “LTM OFF in MN” through the NG- RAN node configuration update to the SN, when the LTM is de-configured in the MN. The SN may receive the LTM indicator indicating the updated configuration state “LTM ON in SN” through the NG-RAN node configuration update to the MN, when the LTM is de-configured in the SN.

[0033] In some embodiments, upon transmitting the LTM indicator to the SN, the MN may be configured to receive upon activating the DC configuration in the UE 105, subsequently, an updated configuration state of LTM in the SN through the NG-RAN node configuration update upon occurrence of the event. The SN may transmit the LTM indicator indicating the updated configuration state “LTM ON in SN” through the NG-RAN node configuration update to the MN, when the LTM is configured in the SN after activating the DC configuration in the UE 105. The MN may receive the LTM indicator indicating the updated configuration state “LTM ON in SN” through the NG-RAN node configuration update to the MN, when the LTM is configured in the SN after activation of the DC configuration in the UE 105. Similarly, the SN may transmit the LTM indicator indicating the updated configuration state “LTM OFF in SN” through the NG-RAN node configuration update to the MN, when the LTM is de-configured in the SN. The MN may receive the LTM indicator indicating the updated configuration state “LTM OFF in SN” through the NG-RAN node configuration update to the MN, when the LTM is de-configured in the SN.

[0034] In an embodiment, when the LTM indicator is transmitted simultaneously by the MN and the SN for configuring the LTM, the method comprises providing priority to the LTM indicator received from the MN. As an example, when the NG-RAN node configuration update is transmitted by both the MN and SN, the LTM indicator in the NG-RAN node configuration update transmitted by MN has the priority over the LTM indicator transmitted by the SN. In an embodiment, due to occurrence of event such as configuration of LTM in node currently connected with the UE 105, change in MN, change in SN, handover of the UE 105 to a node which support LTM and handover of the UE 105 to a node which does not support LTM, the MN or the SN may transmit the NG-RAN node configuration with the LTM indicator to ensure coordination between the MN and the SN during occurrence of the event. This will avoid resource wastage as the MN and the SN communicate with each other while performing LTM configuration in respective nodes.

[0035] FIG. 2 shows a detailed block diagram of gNodeB Control Unit (gNB-CU) 101, in accordance with some embodiments of the present disclosure.

[0036] In some implementations, the gNB-CU 101 may include an I/O interface 201, a processor 203 and a memory 205. In an embodiment, the memory 205 may be communicatively coupled to the processor 203. The processor 203 may be configured to perform one or more functions of the gNB-CU 101 for co-ordination between Master Cell Group (MCG) and Secondary Cell Group (SCG), using the data 207 and the one or more modules 209 of the gNB-CU 101. In an embodiment, the memory 205 may store data 207. Although the FIG. 2 shows the hardware components of the gNB-CU 101, it is to be understood that other embodiments are not limited thereon. In other embodiments, the gNB-CU 101 may include less or a greater number of components. Further, the labels or names of the components are used only for illustrative purpose and does not limit the scope. One or more components can be combined together to perform same or substantially similar technical feature for the coordination between the MCG and the SCG.

[0037] In an embodiment, the data 207 stored in the memory 205 may include, without limitation, L1/L2 Triggered Mobility (LTM) configuration data 211 and other data 213. In some implementations, the data 207 may be stored within the memory 205 in the form of various data structures. Additionally, the data 207 may be organized using data models, such as relational or hierarchical data models. The other data 213 may include various temporary data and files generated by the one or more modules 209.

[0038] In an embodiment, the data 207 may be processed by one or more modules 209 of the gNB-CU 101. In some implementations, the one or more modules 209 may be communicatively coupled to the processor 203 for performing one or more functions of the gNB-CU 101. In an implementation, the one or more modules 209 may include, without limiting to, a transceiver module 215 and other modules 217.

[0039] As used herein, the term module may refer to an Application Specific Integrated Circuit (ASIC), an electronic circuit, a hardware processor 203 (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality. In an implementation, each of the one or more modules 209 may be configured as stand-alone hardware computing units. In an embodiment, the other modules 217 may be used to perform various miscellaneous functionalities on the gNB-CU 101. It will be appreciated that such one or more modules 209 may be represented as a single module or a combination of different modules.

[0040] Firstly, the data 207 and the modules 209 are explained when the gNB-CU 101 is a Master Node (MN).

[0041] In an embodiment, the LTM configuration data 211 may be data related to current configuration state of LTM in the MN. In some embodiment, the LTM configuration data 211 may be data related to updated configuration state of LTM in the MN. The current configuration state and the updated configuration state are one of, LTM ON in MN, LTM OFF in MN, LTM ON in SN, LTM OFF in SN or LTM OFF in BOTH MN and SN. The LTM_OFF in BOTH MN and SN is a default configuration state. The LTM configuration data is updated when NG- RAN node configuration update is received from the SN. As an example, when the LTM indicator indicating the updated configuration state “LTM ON in SN” is received through the NG-RAN node configuration update to the MN, the LTM configuration data 211 may be updated which indicates that the LTM is configured in SN.

[0042] In an embodiment, the transceiver module 215 of the MN may be configured for transmitting during a Dual Connectivity (DC) setup procedure for a User Equipment (UE) 105, a Layerl/Layer2 Triggered Mobility (LTM) indicator indicating current configuration state of LTM in a Master Node (MN) to a Secondary node (SN), through a Secondary Node (S-Node) addition request, to activate DC configuration in the UE 105. Referring to FIG. 3A, at step 1, the LTM is configured in the MN before activation of the DC configuration in the UE 105. Upon DC configuration, the transceiver module 215 of the MN transmits the LTM indicator indicating the current configuration state “LTM ON in MN” through the S-Node addition request to the SN.

[0043] In an embodiment, upon activating the DC configuration in the UE 105, the transceiver module 215 of the MN may be configured for transmitting subsequently, an updated configuration state of LTM in the MN through a Next-Generation Radio Access Network (NG- RAN) node configuration update upon occurrence of an event. The event may include, at least one of, configuration of LTM in node currently connected with the UE 105, change in MN, change in SN, handover of the UE 105 to a node which support LTM and handover of the UE 105 to a node which does not support LTM. Referring to FIG. 3B, at step 1, UE is configured in DC configuration, however, LTM is not configured in UE. At step 2, the transceiver module 215 of the MN transmits the LTM indicator indicating the current configuration state “LTM OFF in MN” through the S-Node addition request to the SN. At step 3, the acknowledgment for the S-Node addition request is received. At step 4, the LTM is configured in the MN after activation of the DC configuration in the UE 105. Upon LTM configuration, the transceiver module 215 of the MN transmits the LTM indicator indicating the updated configuration state “LTM ON in MN” through the NG-RAN node configuration update to the SN (step 5). In some embodiments, when the LTM is de-configured in the MN, the transceiver module 215 of the MN transmits the LTM indicator indicating the updated configuration state “LTM OFF in MN” through the NG-RAN node configuration update to the SN. Referring to FIG. 3C, at step 1, UE is configured in DC configuration, however, LTM is not configured in UE. At step 2, the transceiver module 215 of the MN transmits the LTM indicator indicating the current configuration state “LTM OFF in MN” through the S-Node addition request to the SN. At step 3, the acknowledgment for the S-Node addition request is received. At step 4, the LTM is configured in the MN after activation of the DC configuration in the UE 105. Upon LTM configuration, the transceiver module 215 of the MN transmits the LTM indicator indicating the updated configuration state “LTM ON in MN” through the NG-RAN node configuration update to the SN (step 5). At step 6, the LTM is de-configured in the MN. Upon LTM deconfiguration, the transceiver module 215 of the MN transmits the LTM indicator indicating the updated configuration state “LTM OFF in MN” through the NG-RAN node configuration update to the SN (step 7).

[0044] In some embodiment, upon activating the DC configuration in the UE 105, the transceiver module 215 of the MN may be configured for receiving subsequently, an updated configuration state of LTM in the SN through the NG-RAN node configuration update upon occurrence of the event. Referring to FIG. 3D, at step 1, UE is configured in DC configuration, however, LTM is not configured in UE. At step 2, the transceiver module 215 of the MN transmits the LTM indicator indicating the current configuration state “LTM OFF in MN” through the S-Node addition request to the SN. At step 3, the acknowledgment for the S-Node addition request is received. At step 4, the LTM is configured in the SN after activation of the DC configuration in the UE 105. Upon LTM configuration, the transceiver module 215 of the SN transmits the LTM indicator indicating the updated configuration state “LTM ON in SN” through the NG-RAN node configuration update to the MN (step 5). In some embodiments, when the LTM is de-configured in the SN, the transceiver module 215 of the MN receives LTM indicator indicating the updated configuration state “LTM OFF in SN” through the NG- RAN node configuration update. Referring to FIG. 3E, at step 1, UE is configured in DC configuration, however, LTM is not configured in UE. At step 2, the transceiver module 215 of the MN transmits the LTM indicator indicating the current configuration state “LTM OFF in MN” through the S-Node addition request to the SN. At step 3, the acknowledgment for the S-Node addition request is received. At step 4, the LTM is configured in the SN after activation of the DC configuration in the UE 105. Upon LTM configuration, the transceiver module 215 of the SN transmits the LTM indicator indicating the updated configuration state “LTM ON in SN” through the NG-RAN node configuration update to the MN (step 5). At step 6, the LTM is de-configured in the SN. Upon LTM de-configuration, the transceiver module 215 of the SN transmits the LTM indicator indicating the updated configuration state “LTM OFF in SN” through the NG-RAN node configuration update to the MN (step 7). In an embodiment, when the LTM indicator is transmitted simultaneously by the MN and the SN for configuring the LTM, the transceiver module 215 of the MN provides priority to the LTM indicator received from the MN.

[0045] Now, the data 207 and the modules 209 are explained when the gNB-CU 101 is a Secondary Node (SN).

[0046] In an embodiment, the LTM configuration data 211 may be data related to current configuration state of LTM in the SN. Tn some embodiment, the LTM configuration data 211 may be data related to updated configuration state of LTM in the SN. The current configuration state and the updated configuration state are one of, LTM ON in MN, LTM OFF in MN, LTM ON in SN, LTM OFF in SN or LTM OFF in BOTH MN and SN. The LTM_OFF in BOTH MN and SN is a default configuration state. The LTM configuration data is updated when NG- RAN node configuration update is received from the MN. As an example, when the LTM indicator indicating the updated configuration state “LTM ON in MN” is received through the NG-RAN node configuration update to the SN, the LTM configuration data 211 may be updated which indicates that the LTM is configured in MN.

[0047] In an embodiment, the transceiver module 215 of the SN may be configured for receiving during a DC setup procedure for the UE 105, LTM indicator indicating current configuration state of LTM in the MN through the S-Node addition request, to activate the DC configuration in the UE 105. Referring to FIG. 3A, at step 1 , the LTM is configured in the MN before activation of the DC configuration in the UE 105. Upon DC configuration, the transceiver module 215 of the SN receives the LTM indicator indicating the current configuration state “LTM ON in MN” through the S-Node addition.

[0048] In some embodiment, upon activating the DC configuration in the UE 105, the transceiver module 215 of the SN may be configured for transmitting subsequently, an updated configuration state of LTM in the SN through the NG-RAN node configuration update upon occurrence of the event. Referring to FIG. 3D, at step 1, UE is configured in DC configuration, however, LTM is not configured in UE. At step 2, the transceiver module 215 of the MN transmits the LTM indicator indicating the current configuration state “LTM OFF in MN” through the S-Node addition request to the SN. At step 3, the acknowledgment for the S-Node addition request is received. At step 4, the LTM is configured in the SN after activation of the DC configuration in the UE 105. Upon LTM configuration, the transceiver module 215 of the SN transmits the LTM indicator indicating the updated configuration state “LTM ON in SN” through the NG-RAN node configuration update to the MN (step 5). In some embodiments, when the LTM is de-configured in the SN, the transceiver module 215 of the MN receives LTM indicator indicating the updated configuration state “LTM OFF in SN” through the NG- RAN node configuration update. Referring to FIG. 3E, at step 1, UE is configured in DC configuration, however, LTM is not configured in UE. At step 2, the transceiver module 215 of the MN transmits the LTM indicator indicating the current configuration state “LTM OFF in MN” through the S-Node addition request to the SN. At step 3, the acknowledgment for the S-Node addition request is received. At step 4, the LTM is configured in the SN after activation of the DC configuration in the UE 105. Upon LTM configuration, the transceiver module 215 of the SN transmits the LTM indicator indicating the updated configuration state “LTM ON in SN” through the NG-RAN node configuration update to the MN (step 5). At step 6, the LTM is de-configured in the SN. Upon LTM de-configuration, the transceiver module 215 of the SN transmits the LTM indicator indicating the updated configuration state “LTM OFF in SN” through the NG-RAN node configuration update to the MN (step 7). In an embodiment, when the LTM indicator is transmitted simultaneously by the MN and the SN for configuring the LTM, the transceiver module 215 of the MN provides priority to the LTM indicator received from the MN.

[0049] In an embodiment, upon activating the DC configuration in the UE 105, the transceiver module 215 of the SN may be configured for receiving subsequently an updated configuration state of LTM in the MN through the NG-RAN node configuration update upon occurrence of the event. The event may include, at least one of, configuration of LTM in node currently connected with the UE 105, change in MN, change in SN, handover of the UE 105 to a node which support LTM and handover of the UE 105 to a node which does not support LTM. Referring to FIG. 3B, at step 1, UE is configured in DC configuration, however, LTM is not configured in UE. At step 2, the transceiver module 215 of the MN transmits the LTM indicator indicating the current configuration state “LTM OFF in MN” through the S-Node addition request to the SN. At step 3, the acknowledgment for the S-Node addition request is received. At step 4, the LTM is configured in the MN after activation of the DC configuration in the UE 105. Upon LTM configuration, the transceiver module 215 of the MN transmits the LTM indicator indicating the updated configuration state “LTM ON in MN” through the NG- RAN node configuration update to the SN (step 5). In some embodiments, when the LTM is de-configured in the MN, the transceiver module 215 of the MN transmits the LTM indicator indicating the updated configuration state “LTM OFF in MN” through the NG-RAN node configuration update to the SN. Referring to FIG. 3C, at step 1 , UE is configured in DC configuration, however, LTM is not configured in UE. At step 2, the transceiver module 215 of the MN transmits the LTM indicator indicating the current configuration state “LTM OFF in MN” through the S-Node addition request to the SN. At step 3, the acknowledgment for the S-Node addition request is received. At step 4, the LTM is configured in the MN after activation of the DC configuration in the UE 105. Upon LTM configuration, the transceiver module 215 of the MN transmits the LTM indicator indicating the updated configuration state “LTM ON in MN” through the NG-RAN node configuration update to the SN (step 5). At step 6, the LTM is de-configured in the MN. Upon LTM de-configuration, the transceiver module 215 of the MN transmits the LTM indicator indicating the updated configuration state “LTM OFF in MN” through the NG-RAN node configuration update to the SN (step 7).

[0050] FIG. 4A shows a flowchart illustrating a method for co-ordination between Master Cell Group (MCG) and Secondary Cell Group (SCG) by a Secondary Node (SN), in accordance with some embodiments of the present disclosure.

[0051] As illustrated in FIG. 4A, the method 400 may include one or more blocks illustrating a method for co-ordination between Master Cell Group (MCG) and Secondary Cell Group (SCG), in accordance with some embodiments of the present disclosure illustrated in FIG. 2. The method 400 may be described in the general context of computer executable instructions. Generally, computer executable instructions can include routines, programs, objects, components, data structures, procedures, modules, and functions, which perform specific functions or implement specific abstract data types.

[0052] The order in which the method 400 is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the scope of the subject matter described herein. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof.

[0053] At block 401, the method 400 includes transmitting, by a processor 203 of the gNodeB- Control Unit (gNB-CU) 101, during a Dual Connectivity (DC) setup procedure for a User Equipment (UE) 105, a Layerl/Layer2 Triggered Mobility (LTM) indicator indicating current configuration state of LTM in a Master Node (MN) to a Secondary node (SN), through a Secondary Node (S-Node) addition request, to activate a DC configuration in the UE 105. The gNB-CU referred here is a MN. The current configuration state are one of, LTM ON in MN, LTM OFF in MN, LTM ON in SN, LTM OFF in SN or LTM OFF in BOTH MN and SN, wherein LTM_OFF in BOTH MN and SN is a default configuration state. In an embodiment, the processor 203 transmits the LTM indicator indicating the current configuration state “LTM ON in MN” through the S-Node addition request to the SN, when the LTM is configured in the MN before activation of the DC configuration in the UE 105.

[0054] At block 403, the method 400 includes transmitting, by a processor 203, upon activating the DC configuration in the UE 105, subsequently, an updated configuration state of LTM in the MN through a Next- Generation Radio Access Network (NG-RAN) node configuration update upon occurrence of an event. The event may include, at least one of, configuration of LTM in node currently connected with the UE, change in MN, change in SN, handover of the UE to a node which support LTM and handover of the UE to a node which does not support LTM. In an embodiment, the processor 203 transmits the LTM indicator indicating the updated configuration state “LTM ON in MN” through the NG-RAN node configuration update to the SN, when the LTM is configured in the MN after activation of the DC configuration in the UE 105. In some embodiment, the processor 203 transmits the LTM indicator indicating the updated configuration state “LTM OFF in MN” through the NG-RAN node configuration update to the SN, when the LTM is de-configured in the MN.

[0055] At block 405, the method 400 includes receiving, by a processor 203, upon activating the DC configuration in the UE 105, subsequently, an updated configuration state of LTM in the SN through the NG-RAN node configuration update upon occurrence of the event. In an embodiment, the processor 203 receives the LTM indicator indicating the updated configuration state “LTM ON in SN” through the NG-RAN node configuration update to the MN, when the LTM is configured in the SN after activation of the DC configuration in the UE 105. In some embodiment, the processor 203 receives the LTM indicator indicating the updated configuration state “LTM OFF in SN” through the NG-RAN node configuration update to the MN, when the LTM is de-configured in the SN. In an embodiment, when the LTM indicator is transmitted simultaneously by the MN and the SN for configuring the LTM, the processor 203 provides priority to the LTM indicator received from the MN.

[0056] FIG. 4B shows a flowchart illustrating a method for co-ordination between Master Cell Group (MCG) and Secondary Cell Group (SCG) by a Secondary Node (SN), in accordance with some embodiments of the present disclosure. [0057] As illustrated in FIG. 4B, the method 420 may include one or more blocks illustrating a method for co-ordination between Master Cell Group (MCG) and Secondary Cell Group (SCG), in accordance with some embodiments of the present disclosure illustrated in FIG. 2. The method 420 may be described in the general context of computer executable instructions. Generally, computer executable instructions can include routines, programs, objects, components, data structures, procedures, modules, and functions, which perform specific functions or implement specific abstract data types.

[0058] The order in which the method 420 is described is not intended to be construed as a limitation, and any number of the described method blocks can be combined in any order to implement the method. Additionally, individual blocks may be deleted from the methods without departing from the scope of the subject matter described herein. Furthermore, the method can be implemented in any suitable hardware, software, firmware, or combination thereof.

[0059] At block 421, the method 420 includes transmitting, by a processor 203 of the gNodeB- Control Unit (gNB-CU) 101, during a Dual Connectivity (DC) setup procedure for a User Equipment (UE) 105, a Layerl/Layer2 Triggered Mobility (LTM) indicator indicating current configuration state of LTM in a Master Node (MN) through a Secondary Node (S-Node) addition request, to activate a DC configuration in the UE 105. The gNB referred here is a SN. The current configuration states are one of, LTM ON in MN, LTM OFF in MN, LTM ON in SN, LTM OFF in SN or LTM OFF in BOTH MN and SN, wherein LTM_OFF in BOTH MN and SN is a default configuration state.

[0060] At block 423, the method 420 includes transmitting, by a processor 203, upon activating the DC configuration in the UE 105, subsequently, an updated configuration state of LTM in a Secondary Node (SN) through a Next-Generation Radio Access Network (NG-RAN) node configuration update upon occurrence of an event. In an embodiment, the processor 203 transmits the LTM indicator indicating the updated configuration state “LTM ON in SN” through the NG-RAN node configuration update to the MN, when the LTM is configured in the SN after activating the DC configuration in the UE 105. In some embodiment, the processor 203 transmits the LTM indicator indicating the updated configuration state “LTM OFF in SN” through the NG-RAN node configuration update to the MN, when the LTM is de-configured in the SN. [0061] At block 425, the method 420 includes receiving, by a processor 203, upon activating the DC configuration in the UE 105, subsequently an updated configuration state of LTM in the MN through the NG-RAN node configuration update upon occurrence of the event. In an embodiment, the processor 203 receives the LTM indicator indicating the updated configuration state “LTM ON in MN” through the NG-RAN node configuration update to the SN, when the LTM is configured in the MN after activating the DC configuration in the UE 105. In some embodiment, the processor 203 receives the LTM indicator indicating the updated configuration state “LTM OFF in MN” through the NG-RAN node configuration update to the SN, when the LTM is de-configured in the MN. In an embodiment, when the LTM indicator is transmitted simultaneously by the MN and the SN for configuring the LTM, the processor 203 provides priority to the LTM indicator received from the MN.

[0062] FIG. 5 illustrates an embodiment of a gNodeB-Control Unit (gNB-CU) 500. As shown in FIG. 5, the gNB-CU 500 comprises a processor 502, a memory 504, a storage component 506, an input component 508, an output component 510, a communication interface 512, and a bus 514.

[0063] The processor 502, as used herein, means any type of computational circuit that may comprise hardware elements and software elements. The processor 502 may be embodied as a multi-core processor, a single core processor, or a combination of one or more multi-core processors and/or one or more single core processors, a distributed processing system, or the like. The processor 502 may be a Central Processing Unit (CPU)a graphics processing unit (GPU), an accelerated processing unit (APU), an application-specific integrated circuit (ASIC), or another type of processing component.

[0064] The memory 504 includes a non-transitory computer readable medium. Memory 504 includes a random-access memory (RAM), a read only memory (ROM), and/or another type of dynamic or static storage device (e.g., a flash memory, a magnetic memory, and/or an optical memory) that stores information and/or instructions for use by processor 502. The memory 504 comprises machine-readable instructions which are executable by the processor 502. These machine-readable instructions when executed by the processor 502 cause the processor 502 to perform one or more method steps of an embodiment described above.

[0065] The storage component 506 stores information and/or software related to the operation and use of the gNB-CU 500. For example, the storage component 506 may include a hard disk (e.g., a magnetic disk, an optical disk, a magneto-optic disk, and/or a solid-state disk), a compact disc (CD), a digital versatile disc (DVD), a floppy disk, a cartridge, a magnetic tape, and/or another type of non-transitory computer-readable medium, along with a corresponding drive.

[0066] The input component 508 is configured to receive information, such as user input. For example, the input component 508 may include, but not be limited to, a touch screen display, a keyboard, a keypad, a mouse, a button, a switch, and/or a microphone. Additionally, or alternatively, the input component 508 may include a sensor for sensing information (e.g., a global positioning system (GPS), an accelerometer, a gyroscope, and/or an actuator).

[0067] The output component 510 is configured to provide output information from the gNodeB-Control Unit (gNB-CU) 500. For example, the output component 510 may be, but not limited to, a display, a speaker, instructions to an external device, and/or one or more lightemitting diodes (LEDs).

[0068] The communication interface 512 is an interface that provides a communication connection to other devices, such as external devices and internal devices. The connection by the communication interface 512 can be a wired connection, a wireless connection, or a combination of wired and wireless connections, and can be a direct connection or an indirect connection via a communication network that exists between the gNB-CU 500 and other devices. In other words, the standard of the communication interface 512 is not limited.

[0069] The bus 514 acts as an interconnect between the processor 502, the memory 504, the storage component 506, the input component 508, the output component 510, and the communication interface 512 of the gNB-CU 500. The bus 514 may include a wired interconnection or a wireless interconnection.

[0070] The number and arrangement of components shown in FIG. 5 are provided as an example. In practice, Master Node (MN) and Secondary Node (SN) 500 may include additional components, fewer components, different components, or differently arranged components than those shown in FIG. 5. Additionally, or alternatively, a set of components (e.g., one or more components) of the MN and the SN may perform one or more functions described as being performed by another set of components of the MN and the SN. Further, one or more method steps described in any of the embodiments may be performed utilizing a plurality of the MN and the SN in communication with one another.

Claims

We claim:

1. A method comprising : transmitting during a dual connectivity setup procedure for a User Equipment (UE), a Layerl/Layer2 Triggered Mobility (LTM) indicator indicating current configuration state of LTM in a Master Node (MN) to a Secondary node (SN), through a Secondary Node (S-Node) addition request, to activate a Dual Connectivity (DC) configuration in a User Equipment (UE); and performing one of: transmitting upon activating the DC configuration in the UE, subsequently, an updated configuration state of LTM in the MN through a Next- Generation Radio Access Network (NG-RAN) node configuration update upon occurrence of an event; or receiving upon activating the DC configuration in the UE, subsequently, an updated configuration state of LTM in the SN through the NG-RAN node configuration update upon occurrence of the event.

2. The method as claimed in claim 1, wherein the current configuration state and the updated configuration state are one of, LTM ON in MN, LTM OFF in MN, LTM ON in SN, LTM OFF in SN or LTM OFF in BOTH MN and SN, wherein LTM_OFF in BOTH MN and SN is a default configuration state.

3. The method as claimed in claim 1 comprises transmitting the LTM indicator indicating the current configuration state “LTM ON in MN” through the S-Node addition request to the SN, when the LTM is configured in the MN before activation of the DC configuration in the UE.

4. The method as claimed in claim 1 comprises transmitting the LTM indicator indicating the updated configuration state “LTM ON in MN” through the NG-RAN node configuration update to the SN, when the LTM is configured in the MN after activation of the DC configuration in the UE.

5. The method as claimed in claim 1 comprises transmitting the LTM indicator indicating the updated configuration state “LTM OFF in MN” through the NG-RAN node configuration update to the SN, when the LTM is de-configured in the MN.

6. The method as claimed in claim 1 comprises receiving the LTM indicator indicating the updated configuration state “LTM ON in SN” through the NG-RAN node configuration update to the MN, when the LTM is configured in the SN after activation of the DC configuration in the UE.

7. The method as claimed in claim 1 comprises receiving the LTM indicator indicating the updated configuration state “LTM OFF in SN” through the NG-RAN node configuration update to the MN, when the LTM is de-configured in the SN.

8. The method as claimed in claim 1, wherein when the LTM indicator is transmitted simultaneously by the MN and the SN for configuring the LTM, the method comprises providing priority to the LTM indicator received from the MN.

9. The method as claimed in claim 1 , wherein the LTM indicator is a parameter in the S- Node addition request and the NG-RAN node configuration update or a similar procedure over Xn.

10. The method as claimed in claim 1, wherein the event comprises at least one of, configuration of LTM in node currently connected with the UE, change in MN, change in SN, handover of the UE to a node which support LTM and handover of the UE to a node which does not support LTM.

I L A method comprising: receiving during a dual connectivity setup procedure for a User Equipment (UE), a Layerl/Layer2 Triggered Mobility (LTM) indicator indicating current configuration state of LTM in a Master Node (MN) through a Secondary Node (S-Node) addition request, to activate a Dual Connectivity (DC) configuration in a User Equipment (UE); and performing one of: transmitting upon activating the DC configuration in the UE, subsequently, an updated configuration state of LTM in a Secondary Node (SN) through a Next-Generation Radio Access Network (NG-RAN) node configuration update upon occurrence of an event; or receiving upon activating the DC configuration in the UE, subsequently an updated configuration state of LTM in the MN through the NG-RAN node configuration update upon occurrence of the event.

12. The method as claimed in claim 11, wherein the current configuration state and the updated configuration state are one, of LTM ON in MN, LTM OFF in MN, LTM ON in SN, LTM OFF in SN or LTM OFF in BOTH MN and SN , wherein LTM_OFF in BOTH MN and SN is a default configuration state.

13. The method as claimed in claim 11 comprises transmitting the LTM indicator indicating the updated configuration state “LTM ON in SN” through the NG-RAN node configuration update to the MN, when the LTM is configured in the SN after activating the DC configuration in the UE.

14. The method as claimed in claim 11 comprises transmitting the LTM indicator indicating the updated configuration state “LTM OFF in SN” through the NG-RAN node configuration update to the MN, when the LTM is de-configured in the SN.

15. The method as claimed in claim 11 comprises receiving the LTM indicator indicating the updated configuration state “LTM ON in MN” through the NG-RAN node configuration update to the SN, when the LTM is configured in the MN after activating the DC configuration in the UE.

16. The method as claimed in claim 11 comprises receiving the LTM indicator indicating the updated configuration state “LTM OFF in MN” through the NG-RAN node configuration update to the SN, when the LTM is de-configured in the MN.

17. The method as claimed in claim 11, wherein when the LTM indicator is transmitted simultaneously by the MN and the SN for configuring the LTM, the method comprises providing priority to the LTM indicator received from the MN.

18. The method as claimed in claim 11 , wherein the LTM indicator is a parameter in the S- Node addition request and the NG-RAN node configuration update or a similar procedure over Xn interface.

19. The method as claimed in claim 11, wherein the event comprises at least one of, configuration of LTM in node currently connected with the UE, change in MN, change in SN, handover of the UE to a node which support LTM and handover of the UE 105 to a node which does not support LTM.

20. A Master Node (MN) configured to: transmit during a dual connectivity setup procedure for a User Equipment (UE), a Layerl/Layer2 Triggered Mobility (LTM) indicator indicating current configuration state of LTM in a Master Node (MN) to a Secondary node (SN), through a Secondary Node (S-Node) addition request, to activate a Dual Connectivity (DC) configuration in a User Equipment (UE); and perform one of: transmit upon activating the DC configuration in the UE, subsequently, an updated configuration state of LTM in the MN through a Next-Generation Radio Access Network (NG-RAN) node configuration update upon occurrence of an event; or receive upon activating the DC configuration in the UE, subsequently, an updated configuration state of LTM in the SN through the NG-RAN node configuration update upon occurrence of the event.

21. A Secondary Node (SN) configured to: receive during a dual connectivity setup procedure for a User Equipment (UE), a Layerl/Layer2 Triggered Mobility (LTM) indicator indicating current configuration state of LTM in a Master Node (MN) through a Secondary Node (S-Node) addition request, to activate a Dual Connectivity (DC) configuration in a User Equipment (UE); and performing one of: transmit upon activating the DC configuration in the UE, subsequently, an updated configuration state of LTM in a Secondary Node (SN) through a Next-Generation Radio Access Network (NG-RAN) node configuration update upon occurrence of an event; or receive upon activating the DC configuration in the UE, subsequently an updated configuration state of LTM in the MN through the NG-RAN node configuration update upon occurrence of the event.