User equipment configured for conditional handover using dual connectivity

Abstract

A user device is provided that is configured for dual connectivity and also configured to support conditional handover (CHO). The user device is configured to receive a first configuration for the source primary cell of the master cell group and the source primary cell of the secondary cell group, a second configuration for the target primary cell of the master cell group and the target primary cell of the secondary cell group, an execution condition that a CHO using dual connectivity can be performed from the source primary cell of the master cell group and the source primary cell of the secondary cell group to the target primary cell of the master cell group and the source primary cell of the secondary cell group when the measurement condition is met, and to measure the source primary cell of the secondary cell group to determine whether the measurement condition is met.

Description

Technical Field

[0001] Various exemplary embodiments generally relate to user equipment and network nodes configured for remote communication and conditional handover (CHO) using dual connectivity.

Background Art

[0002] In 3GPP Release16, a user equipment (UE) is configured with a conditional handover (CHO) command that includes target cell configurations and conditions for performing handover for one or more target cells.

[0003] The CHO configuration received by the UE from the network enables the UE to perform a handover without the need for the network when the conditions in another cell are better than the serving cell in which the UE is currently located. This provides a much more efficient and robust mobility solution for handover, especially when the UE is moving between many different cells. The UE receives the CHO configuration from the network, and the CHO configuration includes the execution conditions for performing a CHO from the serving cell to the target cell. The execution conditions are that the target cell should be better than the serving cell in some way, such as having better radio link quality or signal strength than the serving cell.

[0004] Figure 1 shows network 200, which has two master nodes 201 and 202 that provide UE220 with access to primary cells 211 and 212, respectively. Master nodes 201 and 202 in this example are 5G gNBs. Network 200 also has smaller cells belonging to secondary cell groups (SCGs). Each primary cell in an SCG is known as a primary secondary cell (PSCell). Three PSCells, 213, 214, and 215, are shown here for illustrative purposes, but there may actually be more. Secondary nodes 203, 204, and 205 provide UE220 with access to the primary cells of the SCG (PSCells 213, 214, and 215, respectively).

[0005] When the UE220 is configured for dual connectivity, it can connect to both the master and secondary nodes simultaneously. For example, the UE220 may have wireless connectivity to both the master node 201 and the secondary node 203. Dual connectivity provides much better and more reliable wireless coverage and, overall, a better user experience for the network.

[0006] The conditions for performing a handover (CHO) are based on radio measurements performed by the neighbor cell's UE220 to the currently serving primary and secondary cells. The procedure is presented in the message flow diagram shown in Figure 2.

[0007] Conditional Handover (CHO) is designed to allow UE220 to perform a handover without the need for the serving cell (e.g., primary cell 211) to trigger the handover after receiving a measurement report from the UE. In step 10, UE220 configures the execution conditions for the CHO for a target cell, such as primary cell 212. Using wireless measurements, UE220 evaluates cell 212's neighbor cells against a threshold or against a serving cell, in this case primary cell 211. When a measurement comparing a neighbor cell to a threshold or serving cell is met for a particular cell, UE220 executes controls to determine if this cell is an applicable cell. In other words, UE220 compares the cell ID that satisfies the event condition (and therefore is a suitable target cell for the handover) with the cell ID configured in the CHO configuration. If the cell IDs match, UE220 performs the conditional handover and accesses the target cell.

[0008] Some examples of execution conditions are listed below.

[0009] One execution condition is that a neighbor is better than a special cell by an offset. The network is configured so that UE220 compares all neighbor cells against a serving primary / secondary PSCell, e.g., 213. Events are triggered for neighbors that are better than a special cell in the RAN node by an offset. If MN201 constitutes the event, primary cell 211 is considered a special cell. If secondary node 203 constitutes the event, PSCell 213 is a special cell in the SCG.

[0010] Another execution condition is that the conditions in the neighbor cell are better than the threshold.

[0011] In this case, the UE220 is configured to measure the target frequency band for neighbor cells. For these measurements, the UE220 does not consider the serving cell, but it does consider all other cells. This execution condition is triggered when any cell other than the serving cell performs better than the threshold. This is done to ensure that the UE220 does not trigger this event excessively often, as the serving cell is normally expected to exceed the threshold.

[0012] As explained above, CHOs are provided with execution conditions, some of which are the events described above. However, the reporting configuration associated with events is changed to an execution. Instead of triggering a report when an event is fulfilled, an execution is triggered.

[0013] In Release 17, CHOs with Target Secondary Cell Group (SCG) features are standardized. Release 17 provides UEs with access to target PSCells without having to evaluate target PSCell measurements.

[0014] Release 18 is working to enable CHO with target SCG, and currently there are evaluation conditions for target PSCell before CHO execution.

[0015] However, there are currently no provisions for situations where a serving cell performs better than a threshold or has better conditions than a neighboring cell. This situation could occur if UE220 is accessing a serving cell, such as PSCell214, and is configured to perform CHO, but serving PSCell214 has better wireless conditions than the other PSCell213 and 215.

[0016] Currently, there is no viable solution in this situation because interference can occur when the UE takes measurements from two PSCells operating at very close frequencies. Furthermore, while the UE can assess that one PSCell has better wireless conditions than its neighbor, those conditions may not be good enough to maintain a wireless link. [Overview of the Initiative]

[0017] Accordingly, aspects of the present invention provide a user device configured for dual connectivity and configured to support conditional handover (CHO). The user device comprises at least one processor and at least one memory containing computer program code, the at least one memory and computer program code configured to use at least one processor to cause the user device to receive at least a first configuration for the source primary cell of a master cell group and the source primary cell of a secondary cell group, a second configuration for the target primary cell of a master cell group and the target primary cell of a secondary cell group, an execution condition that a CHO using dual connectivity can be performed from the source primary cell of the master cell group and the source primary cell of a secondary cell group to the target primary cell of the master cell group and the source primary cell of a secondary cell group when the measurement condition is met, and to measure the source primary cell of a secondary cell group to determine whether the measurement condition is met.

[0018] This means that the serving (source) primary cell of a secondary cell group and the target (candidate) primary cell of a secondary cell group can be the same PSCell, and that the UE can consider the source primary cell of the secondary cell group as the target cell for the CHO.

[0019] Thus, conditional handover using dual connectivity is possible from the source primary cell and one PSCell to the target primary cell and the same PSCell when the measurement conditions are met. The UE can consider the serving PSCell as a candidate PSCell for CHO without the above issues. This also enables conditional handover when the source PSCell and target PSCell are not the same cell but have overlapping coverage. This also allows the serving PSCell to be considered as the target PSCell if it resides within the coverage areas of two different primary cells in the master cell group.

[0020] The execution conditions may also include access conditions for the target primary cell, so that a CHO using dual connectivity can only be performed from the source primary cell of the master cell group and PSCell to the target primary cell of the master cell group and PSCell when the access conditions for the target primary cell of the master cell group are met.

[0021] Measurement may include measuring the source primary cell of a secondary cell group, and measuring at least one other cell within the secondary cell group that may be a neighbor cell.

[0022] The UE may be further configured to perform a CHO using dual connectivity when the measurement conditions are met, handing over from the source primary cell of the master cell group and the source primary cell of the secondary cell group to the target primary cell of the master cell group and the source primary cell of the secondary cell group.

[0023] Performing a measurement may involve measuring a reference signal signaled from the source primary cell of the secondary cell group to determine whether the measurement conditions are met. The measurement conditions may be met or achieved if the signal intensity of the source primary cell of the secondary cell group is higher than a predetermined threshold.

[0024] Alternatively, performing the measurement may involve comparing the signal measurement of the source primary cell of the secondary cell group with the signal measurement of at least one other cell in the secondary cell group, which may be a neighbor cell. A neighbor cell may be one of several neighbor cells, each consisting only of candidate cells. A candidate cell may be the cell from which the user device receives the target primary cell in the secondary cell group configuration. The secondary cell group configuration may be part of the CHO execution conditions.

[0025] The execution condition may be that the signal measurement of the source primary cell in the secondary cell group is stronger than the signal measurements of all neighbor cells by an offset. Alternatively, the execution condition may be that the signal measurement of the source primary cell in the secondary cell group is not weaker than the strongest measurement from the neighbor cells by an offset.

[0026] In one embodiment, the user device may receive at least two configurations from the network for execution conditions. The configurations may be determined using different measurement methods. The user device may be further configured to receive indications and measure the source primary cell of a secondary cell group for a particular measurement event.

[0027] The user device may be further configured to receive an indication containing a list of candidate cells that will be considered for measurement conditions.

[0028] The user equipment may also be configured to receive a configuration including entering conditions and leaving conditions for evaluating the source primary cell of the secondary cell group with respect to a list of other primary cells of the secondary cell group or with respect to a threshold value.

[0029] In one aspect of the present invention, there is provided an apparatus configured for dual connectivity and configured to support conditional handover CHO. The apparatus includes means for receiving a first configuration for the source primary cell of the master cell group and the source primary cell of the secondary cell group, means for receiving a second configuration for the target primary cell of the master cell group and the target primary cell of the secondary cell group, means for receiving an execution condition that it is possible to perform a CHO using dual connectivity from the source primary cell of the master cell group and the source primary cell of the secondary cell group to the target primary cell of the master cell group and the source primary cell of the secondary cell group when measurement conditions are satisfied, and means for measuring the source primary cell of the secondary cell group to determine whether the measurement conditions are satisfied.

[0030] Aspects of the present invention provide a master node for a mobile communication network, the master node being configured to provide a user equipment with access to a source primary cell within a master cell group, and the network further comprising a target master node configured to provide the user equipment with access to a target primary cell within the master cell group. The network also includes a source secondary node configured to provide the user equipment with access to a source primary cell within a secondary cell group and a target secondary node configured to provide the user equipment with access to a target primary cell within the secondary cell group. The master node comprises at least one processor and at least one memory including computer program code, the at least one memory and the computer program code being configured, using the at least one processor, to cause the master node to send to the user equipment at least a first configuration for the source primary cell of the master cell group and the source primary cell of the secondary cell group, a second configuration for the target primary cell of the master cell group and the target primary cell of the secondary cell group, an execution condition that when a CHO using dual connectivity is such that measurement conditions are satisfied, it is possible to perform a change from the source primary cell of the master cell group and the source primary cell of the secondary cell group to the target primary cell of the master cell group and the source primary cell of the secondary cell group, and instructions for measuring the source primary cell of the secondary cell group to determine whether the measurement conditions are satisfied.

[0031] The master node may be further configured to update the measurement conditions when the serving (source) primary cell of the secondary cell group is changed.

[0032] The master node may be further configured to receive indications from the target master node of multiple metrics, including metrics for considering a secondary cell group's source primary cell as a serving cell, and metrics for not considering a secondary cell group's source primary cell as a serving cell.

[0033] Aspects of the present invention provide a method for user equipment configured for dual connectivity and configured to support a conditional handover CHO, the method comprising the steps of: receiving a first configuration for a source primary cell of a master cell group and a source primary cell of a secondary cell group; receiving a second configuration for a target primary cell of a master cell group and a target primary cell of a secondary cell group; receiving an execution condition that a CHO using dual connectivity can be performed from the source primary cell of the master cell group and the source primary cell of the secondary cell group to the target primary cell of the master cell group and the source primary cell of the secondary cell group when the measurement condition is met; and measuring the source primary cell of the secondary cell group to determine whether the measurement condition is met.

[0034] Another aspect of the present invention provides a method for a mobile communication network, the network comprising: a source master node configured to provide user equipment with access to a source primary cell in a master cell group; a target master node configured to provide user equipment with access to a target primary cell in a master cell group; a source secondary node configured to provide user equipment with access to a source primary cell in a secondary cell group; and a target secondary node configured to provide user equipment with access to a target primary cell in a secondary cell group. The method includes the steps of: sending a first configuration to user equipment for the source primary cell of a master cell group and the source primary cell of a secondary cell group; sending a second configuration to user equipment for the target primary cell of a master cell group and the target primary cell of a secondary cell group; sending an execution condition to user equipment that a CHO using dual connectivity can be performed from the source primary cell of the master cell group and the source primary cell of the secondary cell group to the target primary cell of the master cell group and the source primary cell of the secondary cell group when the measurement condition is met; and sending an instruction to user equipment to measure the source primary cell of the secondary cell group and determine whether the measurement condition is met.

[0035] A further aspect of the present invention provides a computer program product which, when the program is implemented on a computer-readable distribution medium, includes program instructions that cause the device to perform a method according to an embodiment of the present invention.

[0036] Another aspect of the present invention provides a computer program product that, when the program is executed by the device, includes program instructions that cause the device to perform a method according to an embodiment of the present invention.

[0037] Aspects of the present invention provide a computer system comprising one or more processors, at least one data storage, and one or more computer program instructions executed by embodiments of one or more processors of the present invention.

[0038] The present invention will be described with reference to exemplary embodiments and accompanying drawings. [Brief explanation of the drawing]

[0039] [Figure 1] This shows an example of a network where CHO (Chief Human Officer) can be implemented using dual connectivity. [Figure 2] This is a message flow diagram representing a conditional handover. [Figure 3] This is an example of a network to which embodiments of the present invention may be applicable. [Figure 4] This is an example of a network to which embodiments of the present invention can be applied. [Figure 5] This is a simplified schematic block diagram of a network node according to an embodiment of the present invention. [Figure 6] This is a simplified schematic block diagram of a user device according to an embodiment of the present invention. [Figure 7] This is a flowchart illustrating a method according to an embodiment of the present invention. [Figure 8] This is a flowchart illustrating a method according to an embodiment of the present invention. [Figure 9] This is a message flow diagram illustrating a method according to an embodiment of the present invention. [Figure 10] This is a block diagram schematically representing the circuit mechanism of a UE for carrying out the method according to an embodiment of the present invention. [Figure 11] This is a block diagram schematically representing the circuit mechanism of a device for carrying out the method according to an embodiment of the present invention. [Modes for carrying out the invention]

[0040] The following embodiments are illustrative. While this specification may refer to “an,” “one,” or “some” embodiments in some places of the text, this does not necessarily mean that each reference is made to the same embodiment or that certain features apply to only one embodiment. A single feature of a different embodiment may also be combined to provide other embodiments. For the purposes of this disclosure, the phrases “at least one of A or B,” “at least one of A and B,” and “A and / or B” mean (A), (B), or (A and B). For the purposes of this disclosure, the phrases “A or B” and “A and / or B” mean (A), (B), or (A and B). For the purposes of this disclosure, the phrase “A, B, and / or C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B, and C).

[0041] Terms such as "first" and "second" may be used in this specification to describe various elements, but it should be understood that these elements should not be limited by these terms. These terms are used solely to distinguish one element from another. For example, without departing from the scope of the exemplary embodiments, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0042] Embodiments described herein may be implemented in radio systems that include at least one of the following radio access technologies (RATs): Worldwide Interoperability 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, and Enhanced LTE (eLTE). Here, the term "eLTE" refers to LTE Evolution connected to a 5G core. LTE is also known as evolved UMTS terrestrial radio access (EUTRA) or evolved UMTS terrestrial radio access network (EUTRAN). The term "resource" can refer to radio resources such as physical resource blocks (PRB), radio frames, subframes, time slots, subbands, frequency domains, subcarriers, and beams.The terms “transmit” and / or “receive” may refer to wirelessly transmitting and / or receiving via a wireless propagation channel on a radio resource.

[0043] However, the embodiments are not limited to the systems / RATs given as examples, and those skilled in the art may apply the solutions to other communication systems / networks with the required characteristics. Some examples of suitable communication networks include 5G and / or 6G networks. The 3GPP solution for 5G is referred to as New Radio (NR). 6G is envisioned as a further development of 5G. NR is envisioned to use multiple-input multiple-output (MIMO) multiple antenna transmission technology, more base stations or nodes than the current network deployment of LTE (the so-called small cell concept), and this includes macrosites that work in conjunction with smaller local area access nodes and possibly also employ various radio technologies for better coverage and enhanced data speeds. 5G is likely to consist of two or more radio access technologies / radio access networks (RATs / RANs), each optimized for a particular use case and / or spectrum. 5G mobile communications may have a wider range of use cases and related applications, including video streaming, augmented reality, vehicle safety, different sensor and real-time control, and various forms of machine-type applications. 5G is expected to have multiple radio interfaces, namely below 6GHz, cmWave, and mmWave, and multiple radio interfaces that can be integrated with existing legacy radio access technologies such as LTE.

[0044] The current architecture in LTE networks is distributed wirelessly and centralized in the core network. Low-latency applications and services in 5G may require bringing content closer to the wireless, leading to local breakout and multi-access edge computing (MEC). 5G enables analysis and knowledge generation to occur at the data source. This approach requires leveraging resources that may not be continuously connected to the network, such as laptops, smartphones, tablets, and sensors. MEC provides a distributed computing environment for application and service hosting. MEC also has the ability to store and process content in the vicinity of cellular subscribers for faster response times. Edge computing covers a wide range of technologies, including wireless sensor networks, mobile data acquisition, mobile signature analysis, and collaborative distributed peer-to-peer ad-hoc networking and processing, due computing, mobile edge computing, cloudlets, distributed data storage and search, autonomous self-healing networks, remote cloud services, augmented and virtual reality, data caching, the Internet of Things (massive connectivity and / or latency critical), and critical communications (autonomous vehicles, traffic safety, real-time analytics, time-critical control, and healthcare applications). Edge clouds can be brought into the RAN by utilizing network function virtualization (NVF) and software-defined networking (SDN).

[0045] Using edge clouds can mean that access node operations are performed on servers, hosts, or nodes that are operationally coupled to remote radio heads or base stations with radio components, at least in part. Network slicing allows multiple virtual networks to be created on top of a common shared physical infrastructure. These virtual networks are then customized to meet the specific needs of applications, services, devices, customers, or operators.

[0046] In wireless communication, node operations can be performed at least partially in a central / centralized unit (CU) (e.g., a server, host, or node) operationally coupled to a distributed unit (DU) (e.g., a radio head / node). Node operations can also be distributed across multiple servers, nodes, or hosts. It should also be understood that the distribution of work between core network operations and base station operations can vary depending on the implementation. Therefore, a 5G network architecture can be based on a so-called CU-DU partitioning. One gNB-CU controls several gNB-DUs. The term "gNB" in 5G may correspond to the eNB in ​​LTE. One or more gNBs can communicate with one or more UEs. A gNB-CU (central node) can control multiple spatially separated gNB-DUs acting as at least transmit / receive (Tx / Rx) nodes. However, in some embodiments, the gNB-DU (also referred to as DU) may comprise, for example, a radio link control (RLC), medium access control (MAC) layer, and a physical (PHY) layer, while the gNB-CU (also referred to as CU) may comprise layers above the RLC layer, such as a packet data convergence protocol (PDCP) layer, radio resource control (RRC), and an Internet Protocol (IP) layer. Other functional divisions are also possible. Those skilled in the art are considered to be familiar with the OSI model and functions within each layer.

[0047] In some embodiments, a server or CU can generate a virtual network through which the server communicates with radio nodes. Generally, a virtual network may involve a process of combining hardware and software network resources and network functions into a single software-based management entity, i.e., the virtual network. Such a virtual network can provide flexible operational distribution between servers and radio heads / nodes. In practice, any digital signal processing task may be performed in either the CU or the DU, and the boundary through which responsibility shifts between the CU and the DU may be chosen on a case-by-case basis.

[0048] To mention just a few non-exclusive examples, some other possible technological advancements used include software-defined networking (SDN), big data, and all-IP. For example, network slicing can be a form of virtual network architecture that uses the same principles behind software-defined networking (SDN) and network function virtualization (NFV) in fixed networks. SDN and NFV can bring greater network flexibility by allowing traditional network architectures to be divided into virtual elements that can be linked (also through software). Network slicing allows multiple virtual networks to be created on top of a common shared physical infrastructure. The virtual networks are then customized to meet the specific needs of applications, services, devices, customers, or operators.

[0049] Multiple gNBs (access point / nodes), each with a CU and one or more DUs, can be connected to each other via an Xn interface through which the gNBs can negotiate. The gNBs can also be connected via a next-generation (NG) interface to a 5G core network (5GC), which may be the 5G equivalent to the LTE core network. Such a 5G CU-DU separation architecture can be implemented using a cloud / server, where the higher-layer CUs reside in the cloud and the DUs are closer to or house the actual radio and antenna units. Similar plans are underway for LTE / LTE-A / eLTE. If both eLTE and 5G use similar architectures on the same cloud hardware, the next step could be to combine software (SW) so that one common SW controls both the radio access network / technology (RAN / RAT). This would then enable new ways of controlling the radio resources of both RANs. Furthermore, it may be possible to have a configuration where the entire protocol stack is controlled by the same HW and handled by the same radio units as the CUs.

[0050] It should be understood that the distribution of work between core network operations and base station operations may differ from or not exist in LTE. Several other technological advancements that may be used are big data and all-IP, which could change the way networks are built and managed. 5G (or new radio NR) networks are designed to support multiple layers, where MEC servers may be placed between the core and base stations or node B (gNB). It should be recognized that MEC can also be applied to 4G networks.

[0051] 5G can also utilize satellite communications to enhance or complement the coverage of 5G services, for example, by providing backhauling. Possible use cases include providing service continuity for machine-to-machine (M2M) or Internet of Things (IoT) devices or for passengers on vehicles, or ensuring service availability for critical communications and future rail / maritime / air communications. Satellite communications can utilize geostationary earth orbit (GEO) satellite systems, but low earth orbit (LEO) satellite systems, especially megaconstellations (systems with hundreds of (nano) satellites), can also be utilized. Each satellite in a megaconstellation can cover several satellite-enabled network entities that create on-ground cells. On-ground cells can be created through on-ground relay nodes or gNBs located on the ground or within satellites.

[0052] The embodiments are also applicable to narrow-band (NB) Internet of Things (IoT) systems that can enable a wide range of devices and services connected using cellular telecommunications bandwidth. NB-IoT is a narrow-band wireless technology designed for the Internet of Things (IoT) and is one of the technologies standardized by the 3rd Generation Partnership Project (3GPP). Other 3GPP IoT technologies suitable for implementing embodiments include machine-type communication (MTC) and enhanced machine-type communication (eMTC). NB-IoT is particularly focused on enabling low cost, long battery life, and the connection of many devices. NB-IoT technology is deployed "in-band" in the spectrum allocated to Long-Term Evolution (LTE)—using resource blocks within a normal LTE carrier, or in unused resource blocks within the guard band of an LTE carrier, or "standalone" for deployment in a dedicated spectrum.

[0053] The embodiments may also be applicable to device-to-device (D2D), machine-to-machine, and peer-to-peer (P2P) communications. The embodiments may also be applicable to vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), infrastructure-to-vehicle (I2V), or generally V2X or X2V communications.

[0054] Figure 3 illustrates an example of a communication network to which embodiments of the present invention may be applied. The system may comprise a control node 110 providing one or more cells, such as cell 100, and a control node 112 providing one or more other cells, such as cell 102. Each cell, for example, may be a macrocell, microcell, femtocell, or picocell. In another view, a cell may define the coverage area or service area of ​​the corresponding access node. The control nodes 110, 112 may be evolved Node B (eNB) as in LTE and LTE-A, ng-eNB as in eLTE, gNB in ​​5G, or any other device capable of controlling radio communications and managing radio resources within a cell. The control nodes 110, 112 may be referred to as base stations, network nodes, or access nodes.

[0055] The system may be a cellular communication system consisting of a wireless access network of access nodes, each controlling one or more cells. The access node 110 may provide user equipment (UE) 120 (one or more UEs) with wireless access to other networks, such as the Internet. Wireless access may include downlink (DL) communication from the control node to the UE 120 and uplink (UL) communication from the UE 120 to the control node.

[0056] Furthermore, although not shown, one or more local area access nodes may be arranged such that the cells provided by the local area access nodes at least partially overlap the cells of access nodes 110 and / or 112. Local area access nodes may provide wireless access within subcells. Examples of subcells include microcells, picocells, and / or femtocells. Typically, subcells provide hotspots within macrocells. The operation of a local area access node may be controlled by an access node under which subcells are provided. Generally, a control node for a small cell may also be referred to as a base station, network node, or access node.

[0057] Multiple UE120, 122 may exist within the system. Each of them may be serviced by the same or different control nodes 110, 112. UE120, 122 can communicate with each other if a D2D communication interface is established between them.

[0058] The term “Terminal device” or “UE” can refer to any end device that may be capable of wireless communication. For example, but not limited to, a terminal device may also be referred to as a communication device, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MM), or access terminal (AT). Terminal devices may include, but are not limited to, mobile phones, cellular phones, smartphones, voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEEs), laptop-mounted equipment (LMEs), USB dongles, smart devices, wireless customer-premises equipment (CPEs), Internet of Things (IoT) devices, watches or other wearables, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in the context of industrial and / or autonomous processing chains), consumer electronic devices, and devices operating on commercial and / or industrial wireless networks. In the following description, the terms “terminal device,” “communication device,” “terminal,” “user equipment,” and “UE” may be used interchangeably.

[0059] In the case of multiple access nodes in a communication network, access nodes can be connected to each other using interfaces. The LTE specification refers to such interfaces as X2 interfaces. For IEEE 802.11 networks (i.e., Wireless Local Area Networks (WLANs), WiFi), similar interfaces may be provided between access points. Interfaces between an LTE access point and a 5G access point, or between two 5G access points, may be referred to as Xn. Other methods of communication between access nodes may also be possible. Access nodes 110 and 112 may be further connected to the core network 116 of the cellular communication system via another interface. The LTE specification designates the core network as an evolved packet core (EPC), and the core network may comprise a mobility management entity (MME) and gateway nodes. The MME may handle the mobility of terminal devices in a tracking area encompassing multiple cells and may handle signaling connections between terminal devices and the core network. The gateway node may handle data routing in and to / from the core network and terminal devices. The 5G specification designates the core network as the 5G core (5GC), where the core network may include, to name a few, access and mobility management functions (AMF) and user plane functions / gateways (UPF). The AMF may handle non-access stratum (NAS) signaling termination, NAS encryption and integrity protection, registration management, connection management, mobility management, access authentication and authorization, and security context management. UPF nodes may support, for example, packet routing and forwarding, packet inspection, and QoS handling.

[0060] Figure 4 schematically shows a network 300 in which an exemplary embodiment may operate. For the purposes of discussion, the network shown in Figure 4 is a 5G network, but the embodiment may also be applicable to any other current or future wireless access technology.

[0061] Network 300 includes two base stations or gNBs, namely, a master node (MN) 301 and a second master node (MN) 302. MN301 and MN302 provide terminal devices or user equipment (UE) 320 with access to primary cells 311 and 312, respectively, which belong to the primary or master cell group. Primary cells 311 and 312 are macrocells. Other network access nodes and cells in the primary cell group of Network 300 are not shown here for simplification.

[0062] Secondary access nodes 303 and 304 provide access to small cells 313 and 314, respectively. Cells 313 and 314 are the primary cells of a secondary cell group (SCG) and are known as primary secondary cells (PSCells). PSCells 313 and 314 can be, for example, femtocells, picocells, or any other type of small cell. Having an SCG provides much better and more robust network coverage, as described in the background technology section above. PSCell 313 in the SCG is located within the coverage area of ​​both cells 311 and 312 from the master cell group.

[0063] As mentioned, master nodes 301 and 302 can be gNBs, as shown in more detail in Figure 5. Master nodes 301 and 302 are connected via an Xn-C interface. Each master node 301, 302 is connected to the 5G core network via an NG interface and includes at least a central unit (CU) 317 and a distributed unit (DU) 318, providing radio access to the UE 320 via a user interface. Secondary nodes 303 and 304 can also be gNBs with a similar structure and configuration to master nodes 301 and 302.

[0064] The UE320 is configured for conditional handover (CHO). As described in the background technology section above, CHO means that when the UE320 receives a CHO configuration from the network, the UE320 can perform a handover from a serving or source cell to a target or candidate cell, provided that at least one execution condition is met. The UE320 is schematically shown in Figure 6 and includes a processor 321, memory 322, and a chipset or circuitry 323. Memory 322 contains computer program code for performing the method shown in Figure 7.

[0065] The UE320 is configured for dual connectivity, meaning it can connect to both the serving primary cell of a master cell group and the serving primary cell of a secondary cell group. For example, the UE320 may connect to both the serving or source primary cell 211 and the serving PSCell 313.

[0066] As shown in Figure 4, there may be situations where a serving or source PSCell 313 is located in the coverage area of ​​both primary cells 311 and 312. In this situation, if UE 320 needs to relocate to the coverage area of ​​primary cell 312 and perform a CHO from serving primary cell 311 to primary cell 312 as the target primary cell (as is possible for PSCell 314 and other neighbor cells not shown in Figure 4), then source PSCell 313 could potentially become the target PSCell for dual connectivity. However, as mentioned above, there is no provision for this situation to date, and it is not possible for UE 320 to consider serving cell PSCell 313 as the target cell.

[0067] A method of CHO using dual connectivity for UE320 in network 300 shown in Figure 4 according to an embodiment is shown in Figure 7. The network configures UE320 with execution conditions for serving PSCell313 that prepare serving PSCell313 as a candidate or target PSCell for target MN302. In step S211, UE320 receives configurations for primary cell 311 as the source primary cell of the master cell group and for PSCell313 as the source primary cell of the secondary cell group. In step S212, UE230 receives configurations for primary cell 312 as the target primary cell of the master cell group and for PSCell213 as the target primary cell of the secondary cell group (configurations for other possible target cells, e.g., PSCell214 from SCG, are also received). In step S213, UE320 receives an execution condition that a CHO using dual connectivity can be performed from source primary cell 311 and PSCell313 to target primary cell 312 and PSCell313 if the measurement conditions are met. The execution condition may include a determination that PSCell313 can be both the source primary cell and the target primary cell of the SCG. In step S214, UE320 measures PSCell313 to determine if the measurement conditions are met.

[0068] This allows CHO using dual connectivity to be performed for UE320 from source primary cell 311 and PSCell313 to target primary cell 312 and PSCell313, provided the measurement conditions are met.

[0069] For example, the UE320 can measure PSCell313 and another PSCell in the secondary cell group (e.g., neighbor cell 314 of PSCell313) to determine if the measurement condition is met. Alternatively, the UE320 can measure PSCell313 and compare the measurement to a threshold to determine if the measurement condition is met.

[0070] The execution conditions also include the condition that access conditions for the target primary cell 312 are met, for example, that the received signal strength of primary cell 312 is greater than the signal strength of source primary cell 311.

[0071] Thus, PSCell313 can be both a serving cell and a target cell, and if the execution conditions are met, PSCell313 is recognized as a candidate PSCell for a CHO using dual connectivity.

[0072] Monitoring of the serving PSCell 313 as the target PSCell in a CHO involving SCG execution can be performed by the UE.

[0073] The execution conditions for CHO are met when the measurement conditions are met. There are various measurements that the UE320 can perform to confirm whether the measurement conditions are met. In one embodiment, the UE320 verifies whether the signal intensity measurement of the serving PSCell313 is better than a predetermined threshold.

[0074] Alternatively, a new measurement event can be defined in which the UE320 compares the signal measurement of the serving PSCell313 with the signal measurement of at least one or all of the neighbor cells, for example, PSCell314. In one embodiment, only the prepared cell or the prepared neighbor cell is considered in the evaluation.

[0075] In another embodiment, UE320 verifies that the signal measurement of the serving PSCell313 is stronger than all other neighbor cell measurements by the amount of the offset.

[0076] In a further embodiment, the UE320 verifies that the signal measurement of the serving PSCell313 is not weaker than the strongest neighbor cell measurement by more than the offset amount.

[0077] In all embodiments, the network can configure two or more measurement conditions for evaluating whether the execution condition is met. For example, the network can configure two conditions for the same serving PSCell313, each condition being evaluated using different metric quantities, one using reference signal received power (RSRP) and the other using, for example, reference signal received quality (RSRQ). In this case, the execution condition is met when both conditions are satisfied.

[0078] Figure 8 shows a method according to an embodiment, in step S410 the network sends the UE320 configuration for the primary cell 311 of the master cell group and the PSCell 313 of the SCG. In step S411 the network sends the UE320 configuration for the target primary cell 312 of the master cell group and the PSCell 314 of the secondary cell group. In step S412 the network sends the UE320 execution conditions that a CHO using dual connectivity can be performed from the source primary cell 311 and PSCell 313 to the target primary cell 312 and PSCell if the measurement conditions are met. Several possible measurement conditions are highlighted above. In step S413 the network instructs the UE320 to perform a measurement on the PSCell 313 and determine whether the measurement conditions are met.

[0079] The network can then send to the UE320, if it is determined that the measurement conditions have been met, a configuration for CHO using dual connectivity from source primary cell 311 and PSCell313 to target primary cell 312 and PSCell313.

[0080] The embodiments are described with reference to the message flow diagram in Figure 9.

[0081] In Step 1, UE320 sends a measurement report indicating potential target primary cells and PSCells. Source MN301 initiates the handover procedure and sends a handover request (Step 2) along with the measurements to target MN302. Target MN302 uses the measurement report from UE320 to determine which target secondary nodes (SNs) to contact and sends SN addition requests to SN303 and SN304, as well as any other SNs in the network not specified (Steps 3-4). The target SNs respond with SN addition request ACKs (Steps 5-6).

[0082] Target MN302 forms a CHO configuration for each target PSCell313 and 314 (Step 7).

[0083] Target MN302 then sets the execution conditions for each target PSCell313 and 314 (Step 8).

[0084] For target PSCell313, since it is identical to serving PSCell313, target MN302 indicates a new execution condition. The execution condition is determined by comparing the signal measurement of serving PSCell313 against a threshold, or by comparing the measurement of serving PSCell313 against the signal measurement of target PSCell (PSCell313 vs. PSCell314).

[0085] Target MN302 indicates at least one of the measurement target and the associated new reporting configuration (Step 9).

[0086] In one alternative embodiment, target MN302 does not indicate execution conditions to source MN301, and therefore source MN301 may be required to generate the reporting configuration itself, as described in step 8. In this example, source MN301 integrates the metric and reporting configuration into a source configuration that associates it with the CHO configuration for each target PSCell313 and 314 (step 10). This is indicated to UE320 using RRCReconfiguration (step 11). UE320 confirms the application of the configuration in step 12.

[0087] If the serving PSCell313 is changed, the network then needs to update its execution conditions (step 13). To this end, target MN302 preemptively sends two execution conditions to serving MN301: one for the target PSCell as serving PSCell313, and the other for the target PSCell which is not the SCG special cell (serving SCG cell PSCell313) but is instead the new serving special cell of the SCG. Source MN301 uses these multiple conditions to set the correct execution conditions for UE320.

[0088] In another embodiment, source MN301 may generate the execution conditions itself.

[0089] In a further embodiment, source MN301 contacts target MN302 to request updated execution conditions. Target MN302 may then respond to source MN301 using the updated measurement configuration.

[0090] UE320 begins monitoring the execution conditions configured for each event (step 14). In one embodiment, UE320 measures the serving PSCell 313 against a threshold, or in an alternative embodiment, UE320 measures the serving PSCell 313 against another PSCell, e.g., PSCell 314. Execution conditions can include entry and exit conditions for entering and exiting a target PSCell. When the entry condition is met (step 15), UE320 considers the target PSCell to be accessible and begins monitoring for exit conditions. Unless the exit condition is met, UE320 considers the target PSCell to be accessible. If the primary cell access condition is met (step 16) and the exit condition is not met (step 17), UE320 then accesses the target PSCell and target primary cell 312 that satisfy the conditions (steps 18-21). The difference between entry and exit conditions is hysteresis, which is illustrated below in one embodiment. JPEG2026517936000002.jpg74164

[0091] Ofn is the measurement-specific offset of the neighbor cell's reference signal (i.e., offsetMO, as defined in measObjectNR, corresponds to the neighbor cell).

[0092] Ocn is the cell-specific offset of the neighbor cell (i.e., cellIndividualOffset as defined in measObjectNR corresponding to the neighbor cell's frequency), and is set to zero if not configured for the neighbor cell.

[0093] Hys is the hysteresis parameter for this event (i.e., the hysteresis defined in reportConfigNR for this event).

[0094] Thres is a threshold set by the network.

[0095] A second embodiment is shown below. JPEG2026517936000003.jpg92167

[0096] Off is the offset parameter for this event (i.e., a7-Offset as defined in reportConfigNR for this event).

[0097] Mp is the measurement result of the serving SpCell without taking any offset into account.

[0098] Ofp is the offset specific to the object being measured in SpCell (i.e., offsetMO as defined in the measObjectNR corresponding to SpCell).

[0099] Ocp is the cell-specific offset of the SpCell (i.e., cellIndividualOffset as defined in the measObjectNR corresponding to the SpCell), and is set to zero if not configured for the SpCell.

[0100] In embodiments, the UE320 may comprise terminal devices of a communication system, such as a user terminal (UT), a computer (PC), a laptop, a tabloid computer, a cellular phone, a mobile phone, a communicator, a smartphone, a palm computer, a mobile transport device (such as a car), a home appliance, or any other communication device commonly referred to herein as a UE. Alternatively, the device may be provided within such a terminal device. Furthermore, the device may be or comprise a module that provides connectivity (to be attached to the UE), such as a plug-in unit, a "USB dongle," or any other type of unit. The unit may be installed inside the UE or attached to the UE using a connector or even wirelessly.

[0101] In the embodiment shown in Figure 10, the circuitry in the UE320 is schematically illustrated. The UE320 can perform some of the functions of the process described above, such as the steps shown in Figure 7.

[0102] The UE320 may further include a radio interface (TRX) 16 having hardware and / or software for providing communication connectivity according to one or more communication protocols. For example, the TRX may provide the device with the ability to communicate to access a radio access network.

[0103] The device may also include a user interface 18, which may include, for example, at least one keypad, a microphone, a touch display, a display, a speaker, and the like. The user interface may be used by the user to control the device.

[0104] The control circuit mechanism 324 may include one or more associated circuit mechanisms 321 for performing functions according to any of the embodiments.

[0105] Embodiments such as those shown in Figure 11 provide an apparatus 301 (which also applies to apparatuses 302, 303, and 304) comprising at least one processor and a control circuit mechanism (CTRL) 52 such as at least one memory 54 for storing instructions, whereupon the instructions, when executed by at least one processor, cause the apparatus to perform at least one of the processes described above. In one example, at least one memory and computer program code (software) are configured to cause the apparatus to perform one of the processes described above using at least one processor. The memory can be implemented using any suitable data storage technology such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory. The memory may include a database for storing data.

[0106] In an embodiment, the device 301 may be or be located within a network node, such as in a 5G gNB / gNB-CU / gNB-DU. In an embodiment, the device may be the network node 301 or be located within it. The device may be made to perform some of the functions of the process described above, such as the steps in Figure 8.

[0107] The device may further include a communication interface (TRX) 56 having hardware and / or software for achieving communication connectivity according to one or more communication protocols. For example, the TRX may provide the device with the ability to communicate with, for example, at least one user device.

[0108] The device may also include a user interface 58, which may include, for example, at least one keypad, a microphone, a touch display, a display, a speaker, and the like. The user interface may be used by the user to control the device.

[0109] The control circuit mechanism 52 may include a circuit mechanism 60 for performing a method step according to any of the embodiments described herein.

[0110] In some embodiments, a CU-DU (Central Unit-Distributed Unit) architecture is implemented. In such embodiments, the device 50 may be located within a central unit (e.g., a control unit, edge cloud server, server) operably coupled (e.g., via a wireless or wired network) to distributed units (e.g., remote wireless heads / nodes). That is, the central unit (e.g., edge cloud server) and wireless nodes may be standalone devices communicating with each other via a wireless path or a wired connection. Alternatively, the central unit and wireless nodes may reside within the same entity communicating via a wired connection, etc. The edge cloud or edge cloud server may service multiple wireless nodes or wireless access networks. In some embodiments, at least some of the processes described may be performed by the central unit. In other embodiments, the device may instead be located within distributed units, and at least some of the processes described may be performed by the distributed units. In some embodiments, the execution of at least some of the functions of device 130 or 131 may be shared between two physically separate devices (DU and CU) forming a single operational entity. Therefore, the apparatus may appear to represent an operational entity comprising one or more physically separate devices for performing at least some of the described processes. In embodiments, the apparatus controls the execution of the processes regardless of its location and where the processes / functions are performed.

[0111] In one embodiment, a device performing at least some of the embodiments described comprises at least one processor and at least one memory containing computer program code, the at least one memory and computer program code configured to use the at least one processor to perform a function according to any one of the embodiments described for the device. According to one embodiment, when at least one processor executes the computer program code, the computer program code causes the device to perform a function according to any one of the embodiments described for the device. According to another embodiment, a device performing at least some of the embodiments comprises at least one processor and at least one memory containing computer program code, the at least one processor and computer program code perform at least some of the functions according to any one of the embodiments described for the device. Thus, the at least one processor, memory and computer program code form processing means for performing at least some of the embodiments described for the device. According to yet another embodiment, a device performing at least some of the embodiments comprises a circuit mechanism including at least one processor and at least one memory containing computer program code. When activated, the circuit mechanism causes the device to perform at least some of the functions according to any one of the embodiments described for the device.

[0112] As used in this application, the term “circuit mechanism” refers to all of the following: (a) implementations of circuits that are hardware only, such as implementations in analog and / or digital circuit mechanisms only; (b) combinations of circuits and software (and / or firmware), for example (where applicable): (i) combinations of processors; or (ii) parts of processors / software, including digital signal processors, software, and memory, that work together to cause a device to perform various functions; and (c) circuits such as microprocessors or parts of microprocessors that require software or firmware for operation, even if the software or firmware is not physically present. This definition of “circuit mechanism” applies to all use of the term in this application. As a further example, as used in this application, the term “circuit mechanism” also covers implementations of just one (or more) processors or parts of processors and their associated software and / or firmware. The term “circuit mechanism” also covers, for example, baseband integrated circuits for mobile phones or processor integrated circuits for applications, or similar integrated circuits in servers, cellular network devices, or other network devices, where applicable to specific elements.

[0113] In embodiments, at least some of the processes described may be performed by an apparatus having corresponding means for performing at least some of the processes described. Some exemplary means for performing the processes may include at least one of the following: detectors, processors (including dual-core and multi-core processors), digital signal processors, controllers, receivers, transmitters, encoders, decoders, memory, RAM, ROM, software, firmware, displays, user interfaces, display circuitry, user interface circuitry, user interface software, display software, circuits, antennas, antenna circuitry, and circuitry.

[0114] As used herein, the term "non-transient" is a limitation of the medium itself (i.e., tangible rather than signal-based), rather than a limitation of data storage persistence (e.g., RAM vs. ROM).

[0115] As used herein, the term “means” is understood to mean either in the singular form, i.e., a single element, or in the plural form, i.e., a combination of single elements. Therefore, the technical term “means for [performing A, B, C]” is interpreted to cover a device in which there is only one means for performing A, B, and C, or separate means for performing A, B, and C, or means that partially or completely overlap for performing A, B, and C. Furthermore, the technical term “means for performing A, means for performing B, means for performing C” is interpreted to cover a device in which there is only one means for performing A, B, and C, or separate means for performing A, B, and C, or means that partially or completely overlap for performing A, B, and C.

[0116] The techniques and methods described herein can be implemented by various means. For example, these techniques can be implemented in hardware (one or more devices), firmware (one or more devices), software (one or more modules), or a combination thereof. For hardware implementation, the apparatus of the embodiment can be implemented in one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, other electronic units designed to perform the functions described herein, or a combination thereof. With respect to firmware or software, implementation can be performed through a module of at least one chipset (e.g., procedure, function, etc.) that performs the functions described herein. Software code can be stored in a memory unit and executed by a processor. The memory unit can be implemented within or outside the processor. In the latter case, the memory unit can be coupled to the processor in a communicative manner via various means as known in the art. In addition, the components of the systems described herein may be rearranged and / or complemented by additional components to facilitate the achievement of the various embodiments described herein, and as will be recognized by those skilled in the art, they are not limited to the exact configuration described in the given drawings.

[0117] Embodiments described may also be executed in the form of a computer process defined by a computer program or a part thereof. Embodiments of the described method may be executed by executing at least one part of a computer program containing corresponding instructions. A computer program may be in the form of source code, object code, or some intermediate form, and may be stored in any kind of carrier which may be any entity or device capable of executing the program. For example, a computer program may be stored on a computer program distribution medium readable by a computer or processor. For example, computer program media may be recording media, computer memory, read-only memory, electrical carrier signals, telecommunication signals, and software distribution packages, but are not limited to these. Computer program media may be non-temporary media. Coding of software for performing the embodiments shown and described is well within the scope of those skilled in the art.

[0118] Although the present invention has been described above with reference to examples in accordance with the accompanying drawings, it is clear that the present invention is not limited thereto and can be modified in several ways within the scope of the claims. Therefore, all words and expressions should be interpreted broadly, and they are intended to describe, rather than limit, the embodiments. It will be obvious to those skilled in the art that the concepts of the present invention can be implemented in various ways as the art progresses. Furthermore, it will be obvious to those skilled in the art that the embodiments described can be combined in various ways with other embodiments, although this is not required.

Claims

1. A user device configured for dual connectivity and configured to support conditional handover CHO, At least one processor, The system comprises at least one memory containing computer program code, and the at least one memory and the computer program code are used by the at least one processor to provide at least the user equipment, Receiving a first configuration for the source primary cell of the master cell group and the source primary cell of the secondary cell group, Receiving a second configuration for the target primary cell of the master cell group and the target primary cell of the secondary cell group, The CHO using dual connectivity receives an execution condition that allows the measurement to be performed from the source primary cell of the master cell group and the source primary cell of the secondary cell group to the target primary cell of the master cell group and the source primary cell of the secondary cell group when the measurement conditions are met, To measure the source primary cell of the secondary cell group and determine whether the measurement conditions are met. User equipment configured to perform a specific action.

2. The user device according to claim 1, further configured to perform a CHO using dual connectivity when the measurement conditions are met, and to hand over from the source primary cell of the master cell group and the source primary cell of the secondary cell group to the target primary cell of the master cell group and the source primary cell of the secondary cell group.

3. The user device according to claim 1 or 2, wherein performing a measurement includes measuring a reference signal signaled from the source primary cell of the secondary cell group to determine whether the measurement conditions are met.

4. The user device according to any one of claims 1 to 3, wherein the measurement condition is achieved when the signal intensity of the source primary cell of the secondary cell group is higher than a predetermined threshold.

5. The user device according to claim 1, wherein performing a measurement includes comparing a signal measurement value of the source primary cell in the secondary cell group with a signal measurement value of at least one other cell in the secondary cell group.

6. The user device according to claim 5, wherein the at least one other cell is a neighbor cell.

7. The user device according to claim 6, wherein the neighbor cell is one of a plurality of neighbor cells comprising only candidate cells.

8. The user device according to claim 7, wherein the candidate cell is a cell in which the user device has received a target primary cell in a secondary cell group configuration.

9. The user device according to claim 8, wherein the secondary cell group configuration is part of the CHO execution conditions.

10. The user device according to claim 1, wherein the execution condition is that the signal measurement value of the source primary cell in the secondary cell group is stronger than the signal measurement values ​​of all neighbor cells by an offset.

11. The user device according to claim 1, wherein the signal measurement of the source primary cell of the secondary cell group is not weaker than the strongest measurement from the neighbor cell by an amount of offset.

12. The user device according to any one of claims 1 to 11, wherein the user device receives at least two configurations from the network for the execution conditions.

13. The user device according to claim 12, wherein the above configuration is determined using a different measurement method.

14. The user device according to any one of claims 1 to 13, further configured to receive an indication and measure the source primary cell of the secondary cell group for a specific measurement event.

15. The user device according to any one of claims 1 to 14, further configured to receive an indication including a list of candidate cells to be considered for the measurement conditions.

16. The user device according to any one of claims 1 to 14, further configured to receive a configuration including entry and exit conditions for evaluating the source primary cell of the secondary cell group against a list of other primary cells in the secondary cell group or against a threshold.

17. A device configured for dual connectivity and configured to support conditional handover CHO, Means for receiving a first configuration for the source primary cell of a master cell group and the source primary cell of a secondary cell group, Means for receiving a second configuration for the target primary cell of the master cell group and the target primary cell of the secondary cell group, Means for receiving execution conditions that a CHO using dual connectivity can be performed from the source primary cell of the master cell group and the source primary cell of the secondary cell group to the target primary cell of the master cell group and the source primary cell of the secondary cell group when the measurement conditions are met, A means for measuring the source primary cell of the secondary cell group and determining whether the measurement conditions are met. A device equipped with the following features.

18. A master node for a mobile communications network, the master node is configured to provide user devices with access to a source primary cell within a master cell group, and the network is A target master node configured to provide the user device with access to the target primary cell within the master cell group, A source secondary node configured to provide the user device with access to the source primary cell within the secondary cell group, A target secondary node configured to provide the user device with access to the target primary cell within the secondary cell group, and Furthermore, The master node, At least one processor, The system comprises at least one memory containing computer program code, and the at least one memory and the computer program code are used by the at least one processor to send at least one to the master node. Sending the first configuration for the source primary cell of the master cell group and the source primary cell of the secondary cell group to the user device, Sending a second configuration for the target primary cell of the master cell group and the target primary cell of the secondary cell group to the user device, The CHO using dual connectivity sends to the user device an execution condition that, when the measurement conditions are met, the measurement can be performed from the source primary cell of the master cell group and the source primary cell of the secondary cell group to the target primary cell of the master cell group and the source primary cell of the secondary cell group, Sending a command to the user device to measure the source primary cell of the secondary cell group and determine whether the measurement conditions are met. A master node configured to perform this action.

19. The master node according to claim 18, further configured to update the measurement conditions when the serving primary cell of the secondary cell group is changed.

20. The master node according to claim 18 or 19, further configured to receive indications from the target master node of a plurality of metrics, including metrics for considering the source primary cell of the secondary cell group as a serving cell and metrics for not considering the source primary cell of the secondary cell group as a serving cell.

21. A method for user equipment configured for dual connectivity and configured to support conditional handover CHO, A step of receiving a first configuration for the source primary cell of the master cell group and the source primary cell of the secondary cell group, The steps include receiving a second configuration for the target primary cell of the master cell group and the target primary cell of the secondary cell group, Steps include receiving an execution condition that a CHO using dual connectivity can be performed from the source primary cell of the master cell group and the source primary cell of the secondary cell group to the target primary cell of the master cell group and the source primary cell of the secondary cell group when the measurement conditions are met, A step of measuring the source primary cell of the secondary cell group and determining whether the measurement conditions are met. Methods that include...

22. A method for a mobile communication network, wherein the network is A source master node configured to provide user devices with access to the source primary cell within the master cell group, A target master node configured to provide the user device with access to the target primary cell within the master cell group, A source secondary node configured to provide the user device with access to the source primary cell within the secondary cell group, A target secondary node configured to provide the user device with access to the target primary cell within the secondary cell group, and Equipped with, The aforementioned method, A step of sending a first configuration for the source primary cell of the master cell group and the source primary cell of the secondary cell group to the user device, The steps include sending a second configuration for the target primary cell of the master cell group and the target primary cell of the secondary cell group to the user device, A step of sending to the user device an execution condition that CHO using dual connectivity can be performed from the source primary cell of the master cell group and the source primary cell of the secondary cell group to the target primary cell of the master cell group and the source primary cell of the secondary cell group when the measurement conditions are met, The steps include: sending a command to the user device to measure the source primary cell of the secondary cell group and determine whether the measurement conditions are met; Methods that include...

23. A computer program product which is embodied on a computer-readable distribution medium and includes program instructions, wherein when the program is executed by a device, the device causes the device to perform the method according to claim 21 or 22.

24. A computer program product comprising program instructions, wherein when the program is executed by a device, the device is instructed to perform the method according to claim 21 or 22.

25. One or more processors, At least one data storage device, A computer program instruction executed by the one or more processors associated with the at least one data storage for performing the method according to claim 21 or 22 A computer system equipped with the following features.

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