Connection switching control mechanism in multi-connection communication

Abstract

An apparatus for use by a communication element or function configured to perform multi-connection communication in a communication network, wherein at least two communication links are used to form communication paths by at least two different cells formed by at least one network element or function, the apparatus comprising: at least one processing circuit, and at least one memory for storing instructions to be executed by the processing circuit, wherein the at least one memory and the instructions are configured, together with the at least one processing circuit, to cause the apparatus to at least: determine to execute a link failure recovery process for a first communication link to a first cell; detect that conditions are met for executing a conditional cell change process for a second communication link to a second cell, the conditional cell change process being executed during the link failure recovery process for the first communication link; execute processing for controlling the timing of at least one of the link failure recovery process for the first communication link and the conditional cell change process for the second communication link; and execute at least one of the link failure recovery process and the conditional cell change process based on the result of the processing for controlling the timing.

Description

Technical Field

[0001] Examples of the embodiments relate to apparatus, methods, systems, computer programs, computer program products, and (non-transitory) computer-readable media that can be used to control connection switching in multi-connectivity communications (such as wireless dual-connectivity communications in communication networks based on 3GPP standards), and in particular to apparatus, methods, systems, computer programs, computer program products, and (non-transitory) computer-readable media that can be used to control the process of conditional switching (i.e., cell change) for a connection to a secondary cell, while performing a fault recovery process for a connection to the primary cell. Background Technology

[0002] The following description of the background art may include, but is not limited to, insights, discoveries, understandings, or disclosures or associations made by this disclosure with respect to at least some examples of embodiments of this disclosure, as well as disclosures of related prior art unknown to this invention. Some such contributions of this disclosure may be specifically pointed out below, while others will become apparent from the relevant context.

[0003] The following meanings apply to the abbreviations used in this instruction:

[0004] 3GPP Third Generation Partnership Project

[0005] 4G fourth generation

[0006] 5G (Fifth Generation)

[0007] 5GS 5G system

[0008] ACK confirmation

[0009] BS base station

[0010] CN Core Network

[0011] CPC condition PSCell change

[0012] CPU (Central Processing Unit)

[0013] DC Dual Connection

[0014] DRB Data Radio Bearer eNB Evolved Node BETSI European Telecommunications Standards Institute gNB Next Generation Node BGPRS General Packet Radio Service HO Handover LTE Long Term Evolution LTE-A Advanced LTE MAC Media Access Control MCG Primary Cell Group MN Primary Node MR Multiple RATNF Network Functions NG Next Generation NW Network, Network Side PCell Primary Cell PSCell Primary and Secondary Cells RAN Radio Access Network RAT Radio Access Technology RLF Radio Link Failure RRC Radio Resource Control SCG Secondary Cell Group SN Secondary Node SRB Signaling Radio Bearer UE User Equipment UMTS General Mobile Telecommunications System UP User Plane Summary of the Invention

[0015] According to an example embodiment, for instance, an apparatus is provided for use by a communication element or function configured to perform multi-connection communication in a communication network, wherein at least two communication links are used by at least two different cells formed by at least one network element or function to form a communication path. The apparatus includes: at least one processing circuitry; and at least one memory for storing instructions to be executed by the processing circuitry, wherein the at least one memory and the instructions are configured, together with the at least one processing circuitry, to cause the apparatus to at least: determine to execute a link failure recovery process for a first communication link to a first cell; detect that conditions are met for executing a conditional cell change process for a second communication link to a second cell, the conditional cell change process being executed during the link failure recovery process for the first communication link; execute processing for controlling the timing of at least one of the link failure recovery process for the first communication link and the conditional cell change process for the second communication link; and execute at least one of the link failure recovery process and the conditional cell change process based on the result of the processing for controlling the timing.

[0016] Furthermore, according to an example embodiment, a method is provided for use in a communication element or function configured to perform multi-connection communication in a communication network, wherein at least two communication links are used to form communication paths by at least two different cells formed by at least one network element or function. The method includes: determining to perform a link failure recovery process for a first communication link to a first cell; detecting that conditions are met for performing a conditional cell change process for a second communication link to a second cell, the conditional cell change process being performed during the link failure recovery process for the first communication link; performing processing for controlling the timing of at least one of the link failure recovery process for the first communication link and the conditional cell change process for the second communication link; and performing at least one of the link failure recovery process and the conditional cell change process based on the result of the processing for controlling the timing.

[0017] Based on further refinement, these examples may include one or more of the following features:

[0018] - When performing the link failure recovery process, a first timer can be started, which indicates the time period for initiating the connection reconstruction process for the first communication link to the first cell;

[0019] - In the processing for controlling the timing of at least one of the link failure recovery process for the first communication link and the conditional cell change process for the second communication link, when it is detected that the condition for performing the conditional cell change process for the second communication link is met, the first timer can be stopped and the second timer can be started, which indicates the time period for initiating the connection reconstruction process for the first communication link to the first cell.

[0020] - A communication network control element or function that controls at least one of the first cell and the second cell can receive and process at least two different timer values ​​for a first timer, wherein one of the at least two different timer values ​​is applied to the first timer to indicate the time period for initiating a connection reconstruction process for the first communication link to the first cell, and in the processing of timing for controlling at least one of the link fault recovery process for the first communication link and the conditional cell change process for the second communication link, when it is detected that the condition for executing the conditional cell change process for the second communication link to the second cell is met, the first timer can be stopped and the first timer can be restarted, wherein the other of the at least two timer values ​​is applied to the first timer;

[0021] - It can receive and process at least two different timer values ​​for a first timer from a communication network control element or function that controls at least one of the first cell and the second cell, and can determine whether a measurement report that may potentially lead to a conditional cell change process for the second communication link to the second cell has been sent, and if a measurement report has been sent, it can apply the longer of the at least two different timer values ​​to the first timer for a period of time that indicates the initiation of a connection reconstruction process for the first communication link to the first cell.

[0022] - A communication network control element or function that controls at least one of the first cell and the second cell can receive and process a time value for a first timer and a predetermined threshold, and in the processing of timing for controlling at least one of the link fault recovery process for the first communication link and the conditional cell change process for the second communication link, the remaining time of the first timer can be compared with the predetermined threshold. When the remaining time is greater than the predetermined threshold, the conditional cell change process for the second communication link to the second cell can be executed, and when the remaining time is not greater than the predetermined threshold, the conditional cell change process for the second communication link to the second cell can be skipped.

[0023] - In the processing for controlling the timing of at least one of the link fault recovery process for the first communication link and the conditional cell change process for the second communication link, when it is detected that the condition for executing the conditional cell change process for the second communication link to the second cell is met, the first timer can be stopped, the conditional cell change process for the second communication link to the second cell can be skipped, and the connection reconstruction process for the first communication link to the first cell can be started.

[0024] - An indication of whether a delayed conditional cell change process is set can be received and processed from a communication network control element or function that controls at least one of the first cell and the second cell, and in the timing process for controlling the execution of at least one of the link fault recovery process for the first communication link and the conditional cell change process for the second communication link, when the delayed conditional cell change process is set, the conditional cell change process for the second communication link to the second cell can be executed, the first timer can be stopped, and the second timer can be started to indicate the time period for initiating the connection reconstruction process for the first communication link to the first cell;

[0025] - When performing a link failure recovery process for the first communication link with the first cell, an indication that a link failure exists in the first communication link with the first cell can be sent to the communication network control element or function controlling the second cell, wherein the indication includes information that the conditional cell change process is configured to be executed by the communication element or function.

[0026] - The first communication link can be a link between a communication element or function established in the communication network and the primary cell in the primary cell group; the second communication link can be a link between a communication element or function established in the communication network and the primary and secondary cells in the secondary cell group.

[0027] - The link failure recovery process can be a primary cell group failure recovery process used to restore communication elements or functions with the primary cell in the primary cell group by using communication via a second communication link.

[0028] - A conditional cell change process may include: deattaching from a second cell currently used as a primary / secondary cell, and attaching to a new second cell ready to be used as a primary / secondary cell, wherein the new second cell is controlled by the same communication network control element or function as the second cell currently used as a primary / secondary cell, or by a different communication network control element or function.

[0029] - Communication networks can be based on 3GPP standards.

[0030] According to an example embodiment, an apparatus is provided for use by a communication network control element or function configured to control communication elements or functions in a communication network, wherein at least two communication links are used for at least two different cells to form a communication path, and at least one of the at least two different cells is controlled by the communication network control element or function. The apparatus includes: at least one processing circuit, and at least one memory for storing instructions to be executed by the processing circuit, wherein the at least one memory and the instructions are configured, together with the at least one processing circuit, to cause the apparatus to at least: when performing a link failure recovery process for a first communication link to a first cell, and during the link failure recovery process, perform a conditional cell change process for a second communication link to a second cell, and during the conditional cell change process for the second communication link to the second cell, provide reconfiguration information regarding resource control for the first communication link to the communication network control element or function controlling the target cell.

[0031] Furthermore, according to an example embodiment, a method is provided for use in a communication network control element or function configured to control communication elements or functions in a communication network, wherein at least two communication links are used for at least two different cells to form a communication path, and at least one of the at least two different cells is controlled by the communication network control element or function. The method includes: when performing a link failure recovery process for a first communication link to a first cell, and during the link failure recovery process performing a conditional cell change process for a second communication link to a second cell, and during the conditional cell change process for the second communication link to the second cell, providing reconfiguration information regarding resource control for the first communication link to the communication network control element or function controlling the target cell.

[0032] Based on further refinement, these examples may include one or more of the following features:

[0033] - The communication network control element or function can be configured to control a second cell that forms a communication path with the first communication link when a link failure recovery process for the first communication link is initiated, wherein reconfiguration information can be provided when an indication of a successful conditional cell change is received from the target cell;

[0034] - The communication network control element or function can be configured to control the first cell that forms a communication path with the first communication link when a link failure recovery process for the first communication link is initiated;

[0035] - It can store information on candidate cells that indicate conditional cell changes for a second communication link to a second cell, and can provide reconfiguration information on resource control for a first communication link to each communication network control element or function that controls the candidate cells indicated in the stored information.

[0036] - It can receive and process information from the communication control elements or functions involved in the link failure recovery process of the first link, indicating whether the reconfiguration information on resource control for the first communication link has secondary cell group configuration information, and can use the received information to determine whether to provide the communication network control elements or functions controlling the target cell with reconfiguration information on resource control for the first communication link during the conditional cell change process for the second communication link to the second cell.

[0037] - The first communication link can be a link between a communication element or function established in the communication network and the primary cell in the primary cell group; the second communication link can be a link between a communication element or function established in the communication network and the primary and secondary cells in the secondary cell group.

[0038] - The link failure recovery process can be a primary cell group failure recovery process used to restore communication elements or functions with the primary cell in the primary cell group by using communication via a second communication link.

[0039] - A conditional cell change process may include: deattaching from a second cell currently used as a primary / secondary cell, and attaching to a new second cell ready to be used as a primary / secondary cell, wherein the new second cell is controlled by the same communication network control element or function as the second cell currently used as a primary / secondary cell, or by a different communication network control element or function.

[0040] - Communication networks can be based on 3GPP standards.

[0041] Furthermore, according to embodiments, for example, a computer program product for a computer is provided, comprising a software code portion that, when the product is run on the computer, performs the steps of the methods defined above. The computer program product may include a computer-readable medium on which the software code portion is stored. Furthermore, the computer program product may be directly loaded into the computer's internal memory and / or transmitted via a network through at least one of the processes of uploading, downloading, and pushing. Attached Figure Description

[0042] The following describes some embodiments of this disclosure by way of example and with reference to the accompanying drawings, wherein:

[0043] Figure 1 A schematic diagram illustrating an example of a communication network in which embodiments may be implemented;

[0044] Figure 2 The diagram illustrates a common procedure performed by the CPC during MCG fault recovery.

[0045] Figure 3 The diagram illustrates a common procedure performed by the CPC during MCG fault recovery.

[0046] Figure 4 A signaling diagram illustrating an example of CPC execution during MCG fault recovery is shown;

[0047] Figure 5 A signaling diagram illustrating an example of CPC execution during MCG fault recovery is shown;

[0048] Figure 6 A signaling diagram illustrating an example of CPC execution during MCG fault recovery is shown;

[0049] Figure 7 A signaling diagram illustrating an example of CPC execution during MCG fault recovery is shown;

[0050] Figure 8 A signaling diagram illustrating an example of CPC execution during MCG fault recovery is shown;

[0051] Figure 9 A flowchart illustrating some examples of processes performed in a communication element or function according to an embodiment;

[0052] Figure 10 A schematic diagram illustrating network elements or functions representing communication elements or functions according to some examples of embodiments;

[0053] Figure 11 A signaling diagram illustrating an example of CPC execution during MCG fault recovery is shown;

[0054] Figure 12 A signaling diagram illustrating an example of CPC execution during MCG fault recovery is shown;

[0055] Figure 13 Flowcharts illustrating processes performed in a communication network control element or function according to some examples of embodiments; and

[0056] Figure 14 The diagram illustrates network elements or functions representing communication network control elements or functions according to some examples of embodiments. Detailed Implementation

[0057] Over the past few years, the continuous expansion of communication networks (e.g., wired communication networks such as Integrated Services Digital Network (ISDN), Digital Subscriber Line (DSL)) or wireless communication networks such as CDMA2000 (Code Division Multiple Access) systems, third-generation cellular (3G) (such as Universal Mobile Telecommunications System (UMTS)), fourth-generation (4G) communication networks or enhanced communication networks based on, for example, Long Term Evolution (LTE) or LTE-A Advanced, fifth-generation (5G) communication networks, second-generation cellular (2G) communication networks (such as Global System for Mobile Communications (GSM), General Packet Radio System (GPRS), Global Evolution Enhanced Data Rate (EDGE)) or other wireless communication systems such as Wireless Local Area Networks (WLAN), Bluetooth or Global Microwave Access Interoperability (WiMAX)) has occurred worldwide. Various organizations (such as the European Telecommunications Standards Institute (ETSI), the 3rd Generation Partnership Project (3GPP), the Telecommunications and Internet Convergence Services and Advanced Network Protocols (TISPAN), the International Telecommunication Union (ITU), the 3rd Generation Partnership Project 2 (3GPP2), the Internet Engineering Task Force (IETF), the Institute of Electrical and Electronics Engineers (IEEE), the WiMAX Forum, etc.) are developing standards or specifications for telecommunications networks and access environments.

[0058] Basically, in order to properly establish and process communication between two or more endpoints (e.g., communication stations or elements, such as terminal equipment, user equipment (UE), or other communication network elements, databases, servers, hosts, etc.), one or more network elements or functions (e.g., virtualized network functions) may be involved (such as communication network control elements or functions, such as access network elements, such as access points, radio base stations, relay stations, eNBs, gNBs, etc., and core network elements or functions, such as control nodes, support nodes, service nodes, gateways, user plane functions, access and mobility functions, etc.), which may belong to one communication network system or different communication network systems.

[0059] Dual connectivity concepts (such as multiple radio DCs) are used to improve the performance of communication networks. A UE with multiple Rx / Tx capabilities can be configured to use resources provided by two different nodes via a (non-ideal) backhaul connection; for example, one node provides, for instance, NR access, and the other provides E-UTRA or NR access. One node acts as the primary node (MN), and the other acts as the secondary node (SN). The MN and SN are connected, for example, via a network interface, and at least the MN is connected to the core network.

[0060] In a multi-radio dual-connectivity scenario, an MN is a node that provides control plane connectivity to the core network (e.g., a radio access node, such as a gNB). A secondary node is, for example, a radio access node that provides additional resources to the UE in the case of a DC (controller).

[0061] A primary cell group (MCG) is a group of serving cells associated with an MN, including a primary cell (PCell) and one or more optional secondary cells (SCell).

[0062] On the other hand, a secondary cell group (SCG) is a group of serving cells associated with a SN, including primary and secondary cells (PSCells) and one or more optional SCells.

[0063] MCG and SCG are concepts under the dual connectivity (DC) framework.

[0064] Multiple cells can exist under an MCG, with one cell used to initiate initial access, perform Radio Link Monitoring (RLM) for the MCG, and transmit the Physical Uplink Control Channel (PUCCH). This cell is the PCell. Similarly, a primary cell, or PSCell, also exists under an SCG, which can be understood as the cell under the SCG used for initial access and to perform RLM and PUCCH transmissions for the SCG.

[0065] It should be noted that MN and / or SN can be operated using shared spectrum channel access.

[0066] In MR-DC, for example, there exists an interface between the MN and SN for control plane signaling and coordination. For each MR-DC UE, there is also a control plane connection between the MN and the corresponding CN entity. The MR-DC controls the radio resources of the MN and SN associated with a given UE and is primarily responsible for allocating the radio resources of their cells.

[0067] Figure 1 A schematic diagram illustrating an example of a communication network involving MR-DC is shown. It should be noted that... Figure 1 The network architecture shown is configured to also implement examples of embodiments described below.

[0068] like Figure 1 As shown, communication elements such as UE 10 establish a dual-connectivity-based communication connection with the communication network. In this communication network, in Figure 1 In the example shown, four communication network control elements or functions are located therein, each representing a network node with which UE 10 can communicate. Figure 1 The examples show the corresponding gNBs 20, 30, 40, and 50, but it should be noted that the number and type of communication network control elements that can be used (e.g., other access network elements such as eNBs, base stations, etc.) are not limited to this. Figure 1 Those shown.

[0069] Each of the communication network control elements or functions 20, 30, 40, and 50 controls one or more cells (in Figure 1 The example shown illustrates two cells per gNB (but the number can vary). Figure 1 In the example shown, it is assumed that the communication element or function UE 10 is configured to connect to both gNB 20 and gNB 30 simultaneously (i.e., dual connectivity (DC)). That is, UE 10 in DC can perform transmit / receive via both gNB 20 and gNB 30. For example, UE 10 can receive packets from gNB 20 at a first carrier frequency and receive packets from gNB 30 at a second carrier frequency, or UE 10 can transmit packets to gNB 20 at a first carrier frequency and transmit packets to gNB 30 at a second carrier frequency. Furthermore, one of the gNBs (in...) Figure 1 In the diagram, gNB 20 represents the primary node (MN), where UE 10 is connected to the PCell cell, while gNB 30 is the secondary node (SN), where UE 10 is connected to the PSCell cell. Figure 1 In the scenario shown, gNB 20 forms the MCG, while gNB 30 forms the SCG. The first carrier frequency and the second carrier frequency may or may not overlap.

[0070] It is important to note that Figure 1 The system configurations and communication paths shown are merely examples for illustrative purposes. Obviously, other system configurations and communication paths can be applied in a similar manner.

[0071] During communication, failure conditions such as radio link failure (RLF) can occur. As examples of such failure conditions, RLFs are declared for both the MCG and SCG.

[0072] Typically, in such Figure 1 In the system shown, if an RLF is detected for the MCG, one possibility for handling this situation is a so-called Fast MCG Link Failure Recovery triggered by UE 10. Otherwise, the UE initiates an RRC connection reconstruction procedure.

[0073] During Fast MCG Link Failure Recovery, UE 10 suspends all radio-bearer MCG transmissions and reports the fault to MN via an MCG fault information message using the SCG leg splitting SRB1 or SRB3. The UE includes measurement results available based on the current measurement configuration of both MN and SN in the MCG fault information message. Once Fast MCG Link Failure Recovery is triggered, the UE maintains the current measurement configuration from both MN and SN and continues measurements based on the configuration from MN and SN, if possible. If the UE does not receive an RRC reconfiguration instruction, such as an RRC reconfiguration message (Reconfiguration with sync, i.e., HO command) or an RRC release message within a certain time after Fast MCG Link Failure Recovery is initiated, it initiates an RRC connection reconstruction procedure.

[0074] Upon receiving an MCG fault indication, the MN can send RRC reconfiguration information, such as an RRC reconfiguration message or an RRC release message, to the UE using the SCG tributary that splits SRB1 or SRB3. Upon receiving, for example, an RRC reconfiguration message (Reconfiguration with sync, i.e., HO command), the UE initiates a random access procedure for the target PCell. Upon receiving an RRC release message, the UE releases all radio bearers and configurations.

[0075] It is important to note that in the event of an SCG failure, if the MCG transmission carried by the radio bearer is not suspended, the UE will suspend all SCG transmissions carried by the radio bearer and report the SCG failure information to the MN, instead of triggering a re-establishment. If an SCG failure is detected while all MCG transmissions carried by the radio bearer are suspended, the UE will initiate an RRC connection reconstruction procedure.

[0076] In the following description, communication network architectures based on 3GPP standards for communication networks (such as 5G / NR) will be used as examples of communication networks to illustrate different exemplary embodiments. However, the embodiments are not limited to this architecture. It will be apparent to those skilled in the art that these embodiments can also be applied to other types of communication networks, such as Wi-Fi, Global System for Microwave Access Interoperability (WiMAX), etc. Personal Communication Services (PCS) Wideband Code Division Multiple Access (WCDMA), systems using Ultra Wideband (UWB) technology, Mobile Ad Hoc Networks (MANETs), wired access, etc. Furthermore, without loss of generality, the description of some examples of the embodiments relates to mobile communication networks; however, the principles of this disclosure can be extended and applied to any other type of communication network, such as wired communication networks.

[0077] The following examples and embodiments should be understood as illustrative examples only. Although this description may refer to "a," "an," or "some" examples or embodiments in multiple places, this does not mean that every such reference relates to the same example or embodiment, or that the feature applies only to a single example or embodiment. Individual features of different embodiments may also be combined to provide other embodiments. Furthermore, terms such as "comprising" and "including" should be understood not to limit the described embodiments to consisting only of those features mentioned; these examples and embodiments may also include features, structures, units, modules, etc., not specifically mentioned.

[0078] The basic system architecture of a mobile communication system (telecommunications) communication network, including some examples of embodiments in which it may be applied, may include an architecture having one or more communication networks comprising a radio access network subsystem and a core network. This architecture may include one or more communication network control elements or functions, access network elements, radio access network elements, access service network gateways or base transceivers, such as base stations (BS), access points (AP), NodeBs (NBs), eNBs or gNBs, distributed or centralized units that control a corresponding coverage area or cell, and one or more communication stations (such as communication elements, user equipment or terminal equipment (e.g., UEs)) or another device with similar functionality (such as modem chipsets, chips, modules, etc.) (which may also be part of a station, element, function, or application (such as a UE) capable of performing communication, an element or function that can be used in a machine-to-machine communication architecture, or attached as a separate element to such an element, function, or application capable of performing communication, etc.) that can communicate via one or more channels via one or more communication beams for transmitting various types of data in multiple access domains. Furthermore, core network elements or network functions may be included, such as gateway network elements / functions, mobility management entities, mobile switching centers, servers, databases, etc.

[0079] The general functions and interconnections of the elements and functions described, which also depend on the actual network type, are known to those skilled in the art and are described in the corresponding descriptions, and therefore their detailed descriptions are omitted here. However, it should be noted that several additional network elements and signaling links may be employed for communication to or from elements, functions, or applications (such as communication endpoints, communication network control elements, such as servers, gateways, radio network controllers, and other elements of the same or other communication networks, in addition to those described in detail below).

[0080] The communication network architecture considered in the examples of the embodiments may also be able to communicate with other networks, such as the public switched telephone network or the Internet. The communication network may also be able to support the use of cloud services for its virtual network elements or functions. It should be noted that the virtual network portion of a telecommunications network may also be provided by non-cloud resources (e.g., internal networks). It should be understood that network elements and / or corresponding functions of access systems, core networks, etc., can be implemented using any node, host, server, access node, or entity suitable for such use. Typically, network functions can be implemented as network elements on dedicated hardware, software instances running on dedicated hardware, or virtualized functions instantiated on a suitable platform (e.g., cloud infrastructure).

[0081] Furthermore, as described herein, network elements, such as communication elements (e.g., UE, terminal equipment), control elements or functions (e.g., access network elements, such as base stations (BS), gNBs, radio network controllers, core network control elements or functions, such as gateway elements), or other network elements or functions, and any other elements, functions, or applications, may be implemented in software (e.g., through a computer program product for a computer) and / or in hardware. To perform their respective processes, the corresponding devices, nodes, functions, or network elements may include several parts, modules, units, components, etc. (not shown) required for control, processing, and / or communication / signaling functions. Such components, modules, units, and parts may include, for example, one or more processors or processor units including one or more processing sections for executing instructions and / or programs and / or processing data; storage devices or memory units or components (e.g., ROM, RAM, EEPROM, etc.) serving as working areas for processors or processing sections, for storing instructions, programs, and / or data; input or interface components for inputting data and instructions via software (e.g., floppy disks, CD-ROMs, EEPROMs, etc.); user interfaces (e.g., screens, keyboards, etc.) for providing users with monitoring and operational possibilities; and other interfaces or components for establishing links and / or connections under the control of processor units or sections (e.g., wired and wireless interface components, including radio interface components such as antenna units, components for forming radio communication sections, etc.), wherein the corresponding components forming the interfaces (such as radio communication sections) may also be located at remote sites (e.g., radio head units or radio stations, etc.). It should be noted that in this description, "processing section" should not be considered merely as a physical portion of one or more processors, but may also be considered as a logical division of the processing tasks involved that are performed by one or more processors.

[0082] It should be understood that, according to some examples, a so-called "liquid" or flexible network concept can be adopted, in which the operation and function of network elements, network functions, or other entities of the network can be performed in a flexible manner in different entities or functions (such as in nodes, hosts, or servers). In other words, the "division of labor" among the network elements, functions, or entities involved can vary depending on the circumstances.

[0083] Examples of the embodiments relate to the control of connection handover in multi-connectivity communications (such as wireless dual-connectivity communications in a communication network), specifically, to the control of a process for conditional cell change or handover to a secondary cell, while simultaneously performing a fault recovery process for the connection to the primary cell. That is, examples of embodiments of the invention are applicable, for example, to situations involving conditional PSCell change (CPC) during primary cell group (MCG) fault recovery.

[0084] As described above, MCG fault recovery is used to restore the radio link of PCell in MN using the radio link of PSCell in SN. Figure 1 In the example, it is assumed that PCell is controlled by gNB20 (forming source MN) and PSCell is controlled by gNB30 (forming source SN).

[0085] In the following text, the source MN is referred to as MN1, and the source SN is referred to as SN1. Furthermore, the target MN (i.e., the node that is assumed to become MN during the handover or exchange) is referred to as MN2, and the target SN (i.e., the node that is assumed to become SN during the handover or exchange) is referred to as SN2.

[0086] A UE 10 configured with a specific timer (referred to as timer T316) and a segmented signaling radio bearer (SRB) 1 or SRB3 initiates a process to report an MCG failure when neither the MCG nor the secondary cell group (SCG) transmissions are suspended.

[0087] When an MCG failure occurs, UE 10 follows a similar procedure to that for an SCG failure; that is, UE 10 does not trigger RRC connection re-establishment. Instead, during the link failure recovery process, UE 10 suspends MCG transmissions for all SRBs and data radio bearers (DRBs) (except SRB0). Then, UE 10 resets the MCG-Media Access Control (MAC). The current measurement configurations from both the MN and SN are maintained. Next, UE 10 starts timer T316 and initiates a transmission to the SN via the SRB1 split bearer or SRB3, including MCG failure information (e.g., timer T310 expiration or random access problem, or maximum retransmission count reached), and measurement results for both MCG and SCG.

[0088] Then, UE 10 waits for RRC reconfiguration information (e.g., RRC release or RRC reconfiguration (Reconfiguration with sync / HO command)) from MN1 (i.e., gNB 20). This information will be sent via SN1 (i.e., gNB 30). If such information is received, timer T316 is stopped. Otherwise, if timer T316 expires early, the UE performs connection re-establishment (i.e., link failure recovery is stopped).

[0089] For example Figure 1 Another process in the scenario shown (i.e., DC communication) is conditional PSCell change (CPC) to switch PSCells. After receiving some measurements from the UE, the source PSCell (in Figure 1In the context of a cell controlled by SN1, preparation can be made for one or more target PSCells in the same SN (i.e., other cells in gNB 30) or different nodes (i.e., different SNs). Figure 1 In the example shown, it is assumed that the gNB 50 cell is another candidate to become a PSCell.

[0090] The source PSCell provides the UE 10 with CPC execution conditions and the configuration of the prepared PSCell.

[0091] Once the CPC execution conditions are met at UE 10, UE 10 attaches from the source PSCell and performs access for the target PSCell (which is already prepared for it). According to the example discussed, if the CPC command is configured via SRB1, the UE needs to send an RRC reconfiguration complete message to the MN when the CPC execution conditions are met. This is not necessary if the CPC command is received via SRB3 of the SN.

[0092] It should be noted that if a radio link failure is detected for the MCG during CPC execution, the UE initiates an RRC connection reconstruction procedure.

[0093] The following situations may occur during the processes related to MCG fault recovery and PSCell changes described above.

[0094] During the MCG fault recovery process, a situation may occur where the CPC execution conditions are met. This situation is based on... Figure 2 and 3 The signaling diagram is shown.

[0095] In other words, Figure 2 S210 (or Figure 3 In S310), an RLF is detected at the source PCell, and UE 10 starts timer T316 for MCG fault recovery. Figure 2 S220 or Figure 3 (in S320).

[0096] Based on the above process, Figure 2 S230 (or Figure 3 In S330, UE 10 sends MCG fault information to SN1 (PSCell) (e.g., gNB30). SN1 in Figure 2 S235 (or Figure 3 In S335), MN1 (gNB 20) is notified of MCG fault information. MN1 in Figure 2 S240 (or Figure 3 In S340), the communication network control element (e.g., ...) of the communication network is sent to the communication network control element of the communication network. Figure 1 The gNB 40 shown sends a handover (HO) request to initiate a handover of the UE to MN2 (target PCell). MN2 is in Figure 2 S245 (or Figure 3 The HO request is confirmed in S345.

[0097] Now, while waiting to receive RRC reconfiguration or RRC release via the source PSCell, Figure 2 S250 (or Figure 3 In S350), it is determined that UE 10 meets the CPC execution conditions.

[0098] Therefore, as mentioned above, in Figure 2 S260 (or Figure 3 In S360), UE 10 detaches from the source PSCell and connects to the (new) target PSCell (in this example, it is assumed that this is controlled by gNB 30 (intra-SN CPC) or gNB 50 (inter-SN CPC) which becomes SN2). Therefore, UE 10 in Figure 2 S265 (or Figure 3 The random access procedure for SN2 is executed in S365.

[0099] However, when performing CPC, timer T316 may expire before or during the UE completes random access to the target PSCell (SN2). Figure 2 In the example, for instance, in the case where SN1 and SN2 are in the same entity (gNB 30) within an intra-SN CPC, T316 expires at UE 10 before it manages to send the MCG fault information to the target PSCell. On the other hand, MN1 in Figure 2 In step S270, RRC reconfiguration information is sent to SN1 (source PSCell). However, UE 10, which has already detached from the source PSCell in step S260, cannot receive the RRC reconfiguration information sent by the source PSCell in step S280 (dashed arrow). Therefore, timer T316 expires in S290 and connection re-establishment will be performed.

[0100] Therefore, it can be assumed that if UE 10 has not yet detached from SN1, it may have some opportunity to receive RRC reconfiguration / release from SN1, and save unnecessary interruption time on the user plane (by detaching from the source PSCell) and unnecessary signaling for performing random access to the target PSCell.

[0101] However, if the CPC execution conditions have been met or mobility robustness has been configured (configuring a delayed UE reattachment from the source PSCell to increase the success rate of random access to the target PSCell), waiting to receive an RRC reconfiguration / release from the source PSCell may not be advantageous. In this case, the radio link of the source PSCell can be considered unreliable, and waiting for timer T316 to expire will only increase the likelihood of source PCell outages and delay PCell recovery. Furthermore, waiting after the CPC execution conditions have been met can lead to a failure of the source PSCell, i.e., a secondary radio link failure (S-RLF). Since the UE will detect the RLF on both the PCell and PSCell in this situation, it will perform a re-establishment.

[0102] Furthermore, configuring a longer T316 value to address situations where CPC might be triggered during MCG fault recovery is not optimal. The main drawback of this approach is that PCell recovery will be unnecessarily delayed for: 1) UEs without CPC configured (in cases configured by SN1 without MN1's involvement, MN1 may not know whether the UE has CPC configured), or 2) UEs with CPC configured but not meeting the CPC execution conditions during MCG fault recovery. Delaying MCG fault recovery increases PCell radio link interruptions and postpones recovery.

[0103] exist Figure 3 The document further explains another potential issue that may arise when performing the CPC procedure during MCG fault recovery. Here, in conjunction with... Figure 2 The opposite scenario is described, assuming that timer T316 has not yet expired, i.e., UE 10 attempts to send MCG fault information to the target PSCell. MN1 in Figure 3 The S370 sends RRC reconfiguration information to SN1 (source PSCell). For example, in... Figure 2 In the example described, UE 10, which has already unattached from the source PSCell in step S360, cannot receive the RRC reconfiguration information sent by the source PSCell in step S380 (dashed arrow).

[0104] However, in Figure 3In the example, UE 10 sends MCG fault information to PSCell (SN2) in S383. SN2 notifies MN1 (gNB 20) of the MCG fault information in S385 (compared to S335). Subsequently, MN1 sends RRC reconfiguration information, including a handover command, to SN2 in S387. Now, SN2 can forward the RRC reconfiguration information to UE 10 in S390. Accordingly, UE 10 stops timer T316 and executes the RRC reconfiguration procedure. Therefore, PCell recovery can be completed using information received from the target PSCell.

[0105] However, the signaling used for the MCG recovery process via the target PSCell is inefficient. The signaling in S383, S385, and S387 is essentially the same as that in S330, S335, and S370; that is, it is repeatedly used by the target PSCell to obtain RRC reconfiguration information (RRC reconfiguration / RRC release) from MN1. This repetition increases signaling overhead and further delays the PCell recovery, which can lead to re-establishment if T316 expires before receiving RRC reconfiguration / release from the target PSCell.

[0106] about Figure 4 It shows a signaling diagram illustrating the process of CPC execution during MCG fault recovery, describing the combination with Figure 2 Examples of embodiments related to the described problem.

[0107] Specifically, in such Figure 4 In the example of the embodiment shown, it is ensured that when the CPC execution conditions are met during MCG recovery, the UE has sufficient time to complete CPC execution and receive a new RRC reconfiguration / release from the target PSCell.

[0108] Specifically, in some embodiments, the duration for MCG fault recovery (i.e., based on timer T316) is extended. For example... Figure 4 As shown, the CPC execution condition is met during the MCG fault recovery process. That is, in S410, an RLF is detected at the source PCell, and UE 10 starts timer T316 for MCG fault recovery in S420.

[0109] In S430, UE 10 sends MCG fault information to connection SN1 (PSCell) (e.g., gNB 30). In S435, SN1 notifies MN1 (gNB 20) of the MCG fault information. MN1 then sends the information to the communication network control element (e.g., ...) of the communication network in S440. Figure 1As shown, gNB 40 sends a HO request to initiate a handover of the UE to MN2 (target PCell). MN2 acknowledges the HO request in S445.

[0110] In S450, while waiting to receive RRC reconfiguration or RRC release via the source PSCell, it is determined that UE 10 meets the CPC execution conditions.

[0111] According to the current example of the embodiment, in S455, the timer indicating the time period for MCG fault recovery (i.e., the timer indicating until the re-establishment process will be started, i.e., T316) is stopped.

[0112] In S460, UE 10 detaches from the source PSCell and accesses the (new) target PSCell (in this example, it is assumed that this is controlled by gNB 30 (intra-SN CPC) or gNB 50 (inter-SN CPC) which becomes SN2). Therefore, UE 10 performs the random access procedure for SN2 in S465.

[0113] After timer T316 is stopped when the CPC execution condition is met in S455, when attaching to the target PSCell in SN2, when UE 10 sends MCG fault information to the target cell PSCell in S483, it starts a new timer Tx in S481. It should be noted that, simultaneously, as shown in S470 and S480, attempts to notify the source PSCell about RRC reconfiguration may fail, also as combined with... Figure 2 The situation described in the example.

[0114] In S485, S487, and S490, similar to the process described above, SN2 notifies MN1 (gNB 20) of the MCG fault information, and MN1 then sends RRC reconfiguration information, including a handover command, to SN2. SN2 can now forward the RRC reconfiguration information to UE 10.

[0115] When an RRC reconfiguration or RRC release message is received, UE 10 stops timer TX and executes the RRC reconfiguration procedure (S492). Otherwise, if timer TX expires, the UE performs a re-establishment of the source PCell (S495).

[0116] It should be noted that, according to a further example of the embodiment, the new value of timer TX in S481 is the same as the value of timer T316. That is, timer T316 is actually restarted when an MCG fault message is sent to the target PSCell. However, the value of timer TX can also be different from T316 and can be configured independently.

[0117] According to another example of the embodiment, the MCG fault information sent to the target PSCell in S483 is expanded to include an indication that the timer TX for MCG fault recovery has been (re)started.

[0118] about Figure 5 It shows a signaling diagram illustrating the process of CPC execution during MCG fault recovery, describing the combination with Figure 2 Another example of an embodiment related to the problem described.

[0119] Specifically, also in such Figure 5 In the example of the embodiment shown, it is ensured that when the CPC execution conditions are met during MCG recovery, the UE has sufficient time to complete CPC execution and receive a new RRC reconfiguration / release from the target PSCell.

[0120] Specifically, in some embodiments, the duration for MCG fault recovery (i.e., based on timer T316) is extended. For example... Figure 5 As shown, in S505, MN1 (i.e., the source PCell) provides UE 10 with two values ​​for timer T316: values ​​V1 and V2. It should be noted that more than two different values ​​can also be provided for the timer, which can be applicable to different situations (e.g., as configured in UE 10).

[0121] In S510, an RLF is detected at the source PCell. In S520, UE 10 starts timer T316 for MCG fault recovery. According to the current example of the embodiment, UE 10 applies a short value (e.g., value V1) for example, T316 when it starts the MCG fault recovery process.

[0122] In S530, UE 10 sends MCG fault information to SN1 (PSCell) (e.g., gNB 30). In S535, SN1 notifies MN1 (gNB 20) of the MCG fault information. In S540, MN1 notifies the communication network control element (e.g., ...) of the communication network. Figure 1 The gNB 40 shown sends a HO request to initiate a handover of the UE to MN2 (target PCell). MN2 acknowledges the HO request in S545.

[0123] In S550, while waiting to receive RRC reconfiguration or RRC release via the source PSCell, it is determined that UE 10 meets the CPC execution conditions.

[0124] According to the current example of the embodiment, when it is determined that the CPC condition is met while timer T316 is running, UE 10 applies another value (e.g., a longer value) V2 for T316.

[0125] In S560, UE 10 detaches from the source PSCell and accesses the (new) target PSCell (in this example, it is assumed that this is controlled by gNB 30 (intra-SN CPC) or gNB 50 (inter-SN CPC) which becomes SN2). Therefore, UE 10 performs the random access procedure for SN2 in S565.

[0126] In S583, UE 10 sends MCG fault information to the target PSCell. It should be noted that, simultaneously, as shown in S570 and S580, attempts to notify the source PSCell about RRC reconfiguration may fail, also as combined with... Figure 2 The situation described in the example.

[0127] In S585, S587, and S590, similar to the above process, SN2 notifies MN1 (gNB 20) of the MCG fault information, and MN1 then sends RRC reconfiguration information, including a handover command, to SN2. Now, SN2 can forward the RRC reconfiguration information to UE 10.

[0128] In S595, when an RRC reconfiguration or RRC release message is received, UE 10 stops timer T316 and executes the RRC reconfiguration procedure. Otherwise, if timer T316 expires, the UE performs a re-establishment of the source PCell.

[0129] According to some examples of the embodiments, if UE 10 has triggered a measurement report for SN1 before detecting an RLF in PCell (e.g., a measurement report triggered by an A3 event, which can cause a change in PSCell), it can apply a longer value for T316 (i.e., V2). That is, a longer value can be applied directly to T316 from the beginning.

[0130] about Figure 6 It shows a signaling diagram illustrating the process of CPC execution during MCG fault recovery, describing the combination with Figure 2 Another example of an embodiment related to the problem described.

[0131] Specifically, as in Figure 6 In the example of the illustrated embodiment, when the CPC execution conditions are met during MCG fault recovery, it is ensured that the UE has sufficient time to complete the CPC execution and receive a new RRC reconfiguration / release from the target PSCell. Specifically, according to some examples of the embodiments, the CPC is executed only if the UE 10 believes it can use auxiliary data from the network to complete the CPC execution and receive the RRC reconfiguration / release before the timer T316 for MCG fault recovery expires.

[0132] like Figure 6 As shown, in S605, MN1 (i.e., the source PCell) provides RRC configuration information to UE 10, including the value to be used for timer T316 and a threshold Y indicating a time period shorter than the timer value of T316.

[0133] In S610, an RLF is detected at the source PCell. In S620, UE 10 starts timer T316 for MCG fault recovery.

[0134] In S630, UE 10 sends MCG fault information to SN1 (PSCell) (e.g., gNB 30). In S635, SN1 notifies MN1 (gNB 20) of the MCG fault information. In S640, MN1 notifies the communication network control element (e.g., ...) of the communication network. Figure 1 The gNB 40 shown sends a HO request to initiate a handover of the UE to MN2 (target PCell). MN2 acknowledges the HO request in S645.

[0135] In S650, while waiting to receive RRC reconfiguration or RRC release via the source PSCell, it is determined that UE 10 meets the CPC execution conditions.

[0136] According to the current example of the embodiment, in S655, when the CPC execution conditions are met, UE 10 checks whether the current value of timer T316 is lower than the threshold Y provided by the source PCell in S605. In other words, it checks whether the remaining time until timer T316 expires is long enough to allow the CPC process to complete and for the target PSCell to successfully send reconfiguration information to UE 10.

[0137] If this is the case, the UE performs CPC execution. Otherwise, the UE 10 waits for RRC reconfiguration / release from the source PSCell (i.e., it does not perform (skip) the CPC procedure).

[0138] In S660, assuming the check in S655 is positive, UE 10 detaches from the source PSCell and accesses the (new) target PSCell (in this example, it is assumed that this is controlled by gNB 30 (intra-SN CPC) or gNB 50 (inter-SN CPC) which becomes SN2). Therefore, UE 10 performs the random access procedure for SN2 in S665.

[0139] In S683, the UE 10 sends MCG failure information to the target PSCell. In S685, S687, and S690, similar to the above process, SN2 notifies MN1 (gNB 20) about the MCG failure information, and MN1 in turn sends RRC reconfiguration information including a handover command to SN2. Now, SN2 can forward the RRC reconfiguration information to the UE 10.

[0140] That is, according to the example described in conjunction with Figure 6 The configuration of timer T316 in S605 provides a maximum value for timer T316, that is, timer T316 is started in S620 and if it reaches the maximum value that causes re - establishment, it will expire. In S655, when the CPC execution condition is met, the UE compares the current value of timer T316 (i.e., before expiration) with a threshold Y (a fixed value provided by MN1 in S605). If the current value of timer T316 < Y, the UE performs CPC, otherwise, the UE does not perform CPC and waits to receive RRC reconfiguration / release from SN1. That is, it checks whether the remaining time of T316 before expiration is long enough to complete CPC.

[0141] Regarding Figure 7 , which shows a signaling diagram illustrating the process of CPC execution during MCG failure recovery, describes another example of an embodiment related to the problem described in conjunction with Figure 2 description.

[0142] Specifically, in the example of the embodiment as shown in Figure 7 , the MCG failure recovery process (i.e., performing early recovery of the PCell) depends on whether a predetermined condition has been met and is terminated prematurely.

[0143] As shown in Figure 7 , during the MCG failure recovery process, the CPC execution condition is met. That is, in S710, RLF is detected at the source PCell, and the UE 10 starts timer T316 for MCG failure recovery in S720.

[0144] In S730, the UE 10 sends MCG failure information to the connected SN1 (PSCell) (e.g., gNB 30). In S735, SN1 notifies MN1 (gNB 20) about the MCG failure information. MN1 sends a HO request to the communication network control element of the communication network (e.g., Figure 1 the gNB 40 shown in

[0145] In S750, while waiting to receive RRC reconfiguration or RRC release via the source PSCell, it is determined that UE 10 meets the CPC execution conditions.

[0146] According to the current example of the embodiment, UE 10 stops timer T316 in S760 when the CPC execution condition is met. Furthermore, UE 10 initiates the RRC re-establishment procedure. Therefore, as shown in S770 and S780, the source PSCell notifies the user of the failed RRC reconfiguration attempt, also as in conjunction with... Figure 2 The situation described in the example.

[0147] about Figure 8 It shows a signaling diagram illustrating the process of CPC execution during MCG fault recovery, describing the combination with Figure 2 Another example of an embodiment related to the problem described.

[0148] Specifically, also in such Figure 8 In the illustrated embodiment, the MCG fault recovery process (i.e., performing early recovery of the PCell) terminates prematurely depending on whether predetermined conditions have been met. Specifically, according to the combination... Figure 8 The example described is that when the CPC execution conditions have been met and when UE 10 is configured for mobility robustness / delay access to the target cell, UE 10 stops timer T316.

[0149] like Figure 8 As shown, SN1 provides RRC configuration information to UE 10 in S805, including CPC command flags indicating whether delayed CPC execution or non-delayed CPC execution (i.e., whether mobility robustness settings are applied) is set.

[0150] In S810, an RLF is detected at the source PCell, and UE 10 starts timer T316 in S820 for MCG fault recovery.

[0151] In S830, UE 10 sends MCG fault information to SN1 (PSCell) (e.g., gNB 30). In S835, SN1 notifies MN1 (gNB 20) of the MCG fault information. In S840, MN1 notifies the communication network control element (e.g., ...) of the communication network. Figure 1 The gNB 40 shown sends a HO request to initiate a handover of the UE to MN2 (target PCell). MN2 acknowledges the HO request in S845.

[0152] In S850, while waiting to receive RRC reconfiguration or RRC release via the source PSCell, it is determined that UE 10 meets the CPC execution conditions.

[0153] In S855, UE 10 checks the value of the flag received in S805. If the flag indicates that UE 10 is configured for mobility robustness / delay access to the target PSCell, then UE 10 stops timer T316 and executes the CPC procedure. It should be noted that if timer T316 is stopped and the UE executes the CPC procedure, then according to the example of the embodiment, the UE starts a new timer T (e.g., compared to the combined...). Figure 4 (Example described) to protect the MN fault recovery process initiated via SN2. Otherwise, if the check of this flag results in UE 10 not being configured for mobility robustness / delay access target PSCell, then UE 10 waits for RRC reconfiguration / RRC release information, i.e., does not perform the CPC procedure.

[0154] Regarding S860, after UE 10 has detached from the source PSCell and accessed the target PSCell (in this example, it is assumed that this is controlled by gNB 30 (intra-SN CPC) or gNB 50 (inter-SN CPC) which becomes SN2), UE 10 performs a random access procedure for SN2 in S865.

[0155] In S883, UE 10 sends MCG fault information to the target PSCell. It should be noted that, simultaneously, as shown in S870 and S880, the source PSCell's attempt to notify about RRC reconfiguration may fail, also as combined with... Figure 2 The situation described in the example.

[0156] In S885, S887, and S890, similar to the above process, SN2 notifies MN1 (gNB 20) of the MCG fault information, and MN1 then sends RRC reconfiguration information, including a handover command, to SN2. Now, SN2 can forward the RRC reconfiguration information to UE 10.

[0157] According to some examples of the embodiments, it should be noted that the MCG fault information may include an indication that the UE is configured with CPC configuration, that is, MN1 may not be aware of the CPC configuration within the SN without MN's participation. Using this indication, MN1 may be configured to store RRC reconfiguration / RRC release sent in response to MCG fault recovery for subsequent transmission (in the case where the UE performs MCG fault recovery from the target PSCell).

[0158] According to a further example of the embodiment, SN1 is configured to indicate to MN1 that UE10 is configured with in-SN CPC configuration when forwarding MCG fault information to MN1, which is useful, for example, when the MCG fault information is received via SRB3 of SN1.

[0159] Figure 9 As shown in Figures 4 to 8 The example describes a flowchart of a process performed by a communication element or function (such as UE 10). That is, Figure 9 A flowchart is shown relating to processing performed by a communication element or function (such as UE 10) configured to perform multi-connectivity communication in a communication network (such as a 3GPP-based network), in which at least two communication links are used to form communication paths between at least two different cells formed by at least one network element or function. For example, multi-connectivity involves a scenario where the first communication link is a link between a communication element or function established in the communication network and a primary cell (PCell) in a primary cell group (MCG), and the second communication link is a link between a communication element or function established in the communication network and a primary-secondary cell (PSCell) in a secondary cell group (SCG).

[0160] As mentioned above, the communication network can be based on 3GPP standards. However, according to other examples of the embodiments, other communication standards may also be used.

[0161] In S910, it is determined that a link failure recovery process for the first communication link with the first cell will be executed. For example, the link failure recovery process is a main cell group failure recovery process for restoring the communication element or function of the link with the main cell in the main cell group by using communication via the second communication link.

[0162] According to some examples of the embodiments, when a link failure recovery process is performed, a first timer is started, which indicates the time period during which a connection reconstruction process is initiated for the first communication link to the first cell.

[0163] In S920, conditions are detected to be met for performing a conditional cell change process for a second communication link to a second cell, which will be performed during a link failure recovery process for the first communication link. For example, the conditional cell change process includes: deattaching from the second cell currently used as a PSCell, and attaching to a new second cell ready to be used as a PSCell, wherein the new second cell is controlled by the same communication network control element or function as the current second cell used as a primary / secondary cell (i.e., within-SN case), or by a different communication network control element or function (i.e., between-SN case).

[0164] In S930, timing processing is performed to control at least one of the link fault recovery process for the first communication link and the conditional cell change process for the second communication link.

[0165] According to and combined Figure 4In some examples of embodiments described, in the processing for controlling the timing of at least one of a link fault recovery process for a first communication link and a conditional cell change process for a second communication link, a first timer is stopped when it is detected that a condition for executing the conditional cell change process for the second communication link to the second cell is met. Then, a second timer is started, indicating the time period for initiating a connection reconstruction process for the first communication link to the first cell.

[0166] According to and combined Figure 5 Some examples of the described embodiments involve receiving and subsequently processing at least two different timer values ​​for a first timer from a communication network control element or function that controls at least one of a first cell and a second cell (i.e., MN1 or SN1). One of these at least two different timer values ​​is applied to the first timer to indicate the time period for initiating a connection reconstruction process for a first communication link to the first cell. Furthermore, in the processing for controlling the timing of at least one of the link fault recovery process for the first communication link and the conditional cell change process for the second communication link, the first timer is stopped when a condition for executing the conditional cell change process for the second communication link to the second cell is detected to be met. Then, the first timer is restarted, wherein the other timer value of the at least two timer values ​​is applied to the first timer.

[0167] According to and combined Figure 5 In a further example of an embodiment similar to the described scenario, at least two different timer values ​​for a first timer can be received and processed from a communication network control element or function controlling at least one of the first and second cells (i.e., MN1 or SN1). Furthermore, it is determined whether the UE has sent a measurement report that could potentially lead to a conditional cell change process for the second communication link to the second cell. If so, the longer of the at least two different timer values ​​is applied to the first timer for the period indicative of initiating a connection re-establishment process for the first communication link to the first cell. Otherwise, if no such measurement report has been sent, a shorter timer value can be applied.

[0168] According to and combined Figure 6Some examples of embodiments related to the described examples show that a communication network control element or function controlling at least one of a first cell and a second cell (i.e., MN1 or SN1) receives and processes a time value for a first timer and a predetermined threshold. Furthermore, in the processing for controlling the timing of at least one of the execution of a link fault recovery process for the first communication link and a conditional cell change process for the second communication link, the remaining time of the first timer is compared with the predetermined threshold. When the remaining time is greater than the predetermined threshold, the conditional cell change process for the second communication link to the second cell is executed. Otherwise, when the remaining time is not greater than the predetermined threshold, the conditional cell change process for the second communication link to the second cell is skipped.

[0169] According to and combined Figure 7 In some examples of embodiments described, in the timing process for controlling the execution of at least one of a link fault recovery process for a first communication link and a conditional cell change process for a second communication link, when a condition for executing the conditional cell change process for the second communication link to the second cell is detected to be met, the first timer is stopped. Furthermore, the conditional cell change process for the second communication link to the second cell is skipped, and a connection reconstruction process for the first communication link to the first cell is initiated.

[0170] According to and combined Figure 8 Some examples of the described embodiments involve receiving and processing an indication from a communication network control element or function that controls at least one of the first and second cells (i.e., MN1 or SN1) as to whether a delayed conditional cell change process is set. Furthermore, in the processing for controlling the timing of at least one of the link fault recovery process for the first communication link and the conditional cell change process for the second communication link, when the delayed conditional cell change process is set, a conditional cell change process for the second communication link to the second cell is executed. A first timer is stopped, and a second timer is started to indicate the time period for initiating a connection reconstruction process for the first communication link to the first cell.

[0171] In S940, based on the results of the processing used for control timing, at least one of the link fault recovery process and the conditional cell change process is executed.

[0172] According to some examples of the embodiments, when a link failure recovery process for a first communication link with a first cell is performed (see S910), an indication that a link failure exists in the first communication link with the first cell is sent to a communication network control element or function that controls the second cell, wherein the indication includes information that a conditional cell change process is configured to be executable by the communication element or function.

[0173] Figure 10 It shows the combination as follows Figure 1 and Figures 4 to 8 The described embodiments are schematic diagrams of communication elements or functions (such as UE 10) configured to perform multi-connection communication according to examples of embodiments of this disclosure. It should be noted that the network element or function (such as UE 10) may include other elements or functions besides those described below. Furthermore, even when referring to a network element or function, it may be another device or function with a similar task, such as a chipset, chip, module, application, etc., which may be part of a network element or attached to a network element as a separate element. It should be understood that each block and any combination thereof can be implemented by various components or combinations thereof, such as hardware, software, firmware, one or more processors and / or circuitry.

[0174] Figure 10 The communication element or function 10 shown may include processing circuitry, processing functions, control units, or processor 101 (such as a CPU), adapted to execute instructions given by programs, etc., related to a control process. Processor 101 may include one or more processing portions or functions dedicated to a specific process as described below, or the process may run within a single processor or processing function. The portion used to perform such a specific process may also be provided as a discrete element or within one or more other processors, processing functions, or processing portions, such as in a physical processor like a CPU or in one or more physical or virtual entities. Reference numerals 102 and 103 denote input / output (I / O) units or functions (interfaces) connected to the processor or processing function 101. I / O unit 102 may be used via a first communication link (e.g., to a PCell, such as...) Figure 1 (as shown) communicates with a communication network. I / O unit 103 can be used to communicate via a second communication link (e.g., to PSCell, such as...) Figure 1 (As shown) communicates with a communication network. I / O units 102 and 103 may be combined units including communication devices facing several entities, or may include a distributed structure having multiple different interfaces for different entities. Reference numeral 104 is an example of a memory that can be used to store data and programs to be executed by the processor or processing function 101 and / or as working storage for the processor or processing function 101. It should be noted that memory 104 can be implemented by using one or more memory portions of the same or different types of memory.

[0175] The processor or processing function 101 is configured to perform processing related to the aforementioned control process. Specifically, the processor or processing circuitry or function 101 includes one or more of the following sub-parts. Sub-part 1011 is a processing portion that can be used to determine the portion for executing the link failure recovery process. Part 1011 can be configured to execute according to Figure 9 The processing of S910. Furthermore, the processor or processing circuitry or function 101 may include a sub-part 1012 that can be used as a part for detecting that the CPC condition is met. Part 1012 can be configured to perform according to... Figure 9 The processing of S920. Additionally, the processor or processing circuitry or function 101 may include a sub-section 1013 that can be used as a part for controlling timing. Sub-section 1013 can be configured to perform according to... Figure 9 The processing of S930. Furthermore, the processor or processing circuitry or function 101 may include a sub-part 1014 that can be used as a part for performing link failure recovery and / or CPC. Part 1014 can be configured to perform according to Figure 9 The processing of S940.

[0176] about Figure 11 It shows a signaling diagram illustrating the process of CPC execution during MCG fault recovery, describing the combination with Figure 3 Examples of embodiments related to the described problem.

[0177] As described above Figure 3 As described, the signaling used for the MCG recovery process via the target PSCell is inefficient because specific signaling is repeated. Therefore, according to an example of an embodiment, the CPC process is simplified.

[0178] like Figure 11 As shown, the CPC execution condition is met during the MCG fault recovery process. That is, in S1110, an RLF is detected at the source PCell, and UE 10 starts timer T316 for MCG fault recovery in S1120.

[0179] In S1130, UE 10 sends MCG fault information to connection SN1 (PSCell) (e.g., gNB 30). In S1135, SN1 notifies MN1 (gNB 20) of the MCG fault information. In S1140, MN1 notifies the communication network control element (e.g., ...) of the communication network. Figure 1 As shown, gNB 40 sends a HO request to initiate a handover of the UE to MN2 (target PCell). MN2 acknowledges the HO request in S1145.

[0180] In S1150, while waiting to receive RRC reconfiguration or RRC release via the source PSCell, it is determined that UE 10 meets the CPC execution conditions.

[0181] In S1160, UE 10 detaches from the source PSCell and accesses the (new) target PSCell (in this example, it is assumed that this is controlled by gNB 30 (intra-SN CPC) or gNB 50 (inter-SN CPC) which becomes SN2). Therefore, in S1165, UE 10 performs a random access procedure for SN2.

[0182] In S1170, MN1 sends RRC reconfiguration information (including HO commands) to SN1.

[0183] In the case of inter-SN CPC, the target PSCell (i.e., SN2) sends a notification to the source PSCell (i.e., SN1) in S1172 regarding a successful HO (which is adopted for a CHO). If necessary, a "HO successful" message can be sent to notify the source PSCell to stop transmission to the UE and initiate data forwarding to the target PSCell.

[0184] According to some examples of the embodiments, as option 1, when a "HO success" message is received from the target PSCell, if a message is received from MN1 (in... Figure 11 In the example (the case in S1170), the source PSCell in SN1 provides an RRC reconfiguration / release to the target PSCell in SN2 in S1176. Furthermore, the target PSCell can provide an RRC reconfiguration / release message to the UE immediately after completing random access (S1190). Otherwise, in S1180, the source PSCell notifies the UE of the failed RRC reconfiguration attempt, also as in... Figure 2 The situation described in the example.

[0185] Alternatively, as option 2, according to another example of the embodiment, MN1 is aware of the inter-SN CPC configuration. Therefore, MN1 is configured to proactively forward RRC reconfiguration to SN1 and the ready SN (SN2 in this case) in S1170 and S1178. Furthermore, the (new) target PSCell can provide the UE with an RRC reconfiguration / release message immediately after random access is completed (S1190).

[0186] In S1195, UE 10 stops timer T316 and performs the RRC reconfiguration procedure (in S1190) when it receives an RRC reconfiguration or RRC release message. Otherwise, if the timer expires, the UE performs a re-establishment of the source PCell.

[0187] According to a further example of the embodiment, in the case of CPC within the SN, the target PSCell under the control of the same SN provides an RRC reconfiguration / release message to UE 10 immediately after UE completes random access in S1165.

[0188] In other words, in such Figure 11 In the process shown, the target PSCell can provide RRC reconfiguration information to UE 10 immediately after completing random access, without obtaining it from MN1 (i.e., without the repeated signaling as described above). This reduces signaling overhead and speeds up MCG recovery.

[0189] about Figure 12 It shows a signaling diagram illustrating the process of CPC execution during MCG fault recovery, describing the combination with Figure 3 Another example of an embodiment related to the described problem is provided to simplify the CPC process.

[0190] like Figure 12 As shown, the CPC execution condition is met during the MCG fault recovery process. That is, in S1210, an RLF is detected at the source PCell, and UE 10 starts timer T316 for MCG fault recovery in S1220.

[0191] According to the current example of the embodiment, it is assumed that MN1 is involved in keeping track of all potential PSCells. For this purpose, for example, in S1222 and S1224, MN1 is notified of CPC information initiated by the SN by the cells involved in the CPC (here, the PSCell of SN1 and potential PSCells of SN2). In S1226, MN1 stores corresponding information indicating potential PSCell candidates in memory. It should be noted that the processing according to S1222 to S1226 can be independent of RLF detection (i.e., the initiation of the MCG fault recovery process).

[0192] In S1230, UE 10 sends MCG fault information to connection SN1 (PSCell) (e.g., gNB 30). SN1 notifies MN1 (gNB 20) of the MCG fault information in S1235. MN1 then notifies the communication network control element (e.g., ...) of the communication network in S1240. Figure 1 The gNB 40 shown sends a HO request to initiate a handover of the UE to MN2 (target PCell). MN2 acknowledges the HO request in S1245.

[0193] According to the current example of the embodiment, MN2 indicates to MN1 whether it has configured an SCG to cover cases where the UE receives an RRC reconfiguration from the target PSCell and the configuration provides an incremental (delta) SCG configuration based on problems caused by the source PSCell at the UE. That is, MN1 can learn from MN2 whether MN2 has configured an SCG and / or, if MN2 has configured an SCG, provide a full or incremental configuration for the SN. Using this information, MN1 can determine how to forward the RRC reconfiguration information to the prepared target PSCell (described below as Option 2). For example, to avoid potential problems caused by a changed PSCell for the received RRC reconfiguration sent by MN1, MN1 may send RRC reconfiguration information containing: 1) only an MCG configuration without an SCG; or 2) an MCG with a full SN configuration. In both cases, the change to the source PSCell does not affect the aspect of the received RRC reconfiguration containing an SCG prepared with the source PSCell. In other words, MN1 can decide whether to proactively send the RRC reconfiguration information received from MN2 to the prepared target PSCell, for example, when the RRC reconfiguration does not contain an SCG or contains an SCG with a complete configuration.

[0194] To avoid the complexity of MN decoding the configuration received from MN2, MN2 can indicate to MN1 whether it has configured SCG. In this example, this is achieved by adding the corresponding flag SCG_config_status to the message sent in S1245.

[0195] In S1250, while waiting to receive RRC reconfiguration or RRC release via the source PSCell, it is determined that UE 10 meets the CPC execution conditions.

[0196] In S1260, UE 10 detaches from the source PSCell and accesses the (new) target PSCell (in this example, it is assumed that this is controlled by gNB 30 (intra-SN CPC) or gNB 50 (inter-SN CPC) which becomes SN2). Therefore, in S1265, UE 10 performs a random access procedure for SN2.

[0197] In S1270, MN1 sends RRC reconfiguration information (including HO commands) to SN1.

[0198] In the case of inter-SN CPC, the target PSCell (i.e., SN2) sends a notification to the source PSCell (i.e., SN1) in S1272 regarding a successful HO (which is adopted for a CHO). If necessary, a "HO successful" message can be sent to notify the source PSCell to stop transmission to the UE and initiate data forwarding to the target PSCell.

[0199] According to some examples of the embodiments, as option 1, when a "HO success" message is received from the target PSCell, if a message is received from MN1 (in... Figure 12 In the example (the case in S1270), the source PSCell in SN1 provides an RRC reconfiguration / release to the target PSCell in SN2 in S1276. Furthermore, the target PSCell can provide an RRC reconfiguration / release message to the UE immediately after completing random access (S1290).

[0200] Alternatively, as option 2, according to another example of the embodiment, MN1 knows the inter-SN CPC configuration. Therefore, MN1 is configured, for example, to forward RRC reconfiguration to SN1 and the ready SN (here, SN2) in S1270 and S1278 based on the information stored in S1226. Furthermore, the target PSCell can provide the UE with an RRC reconfiguration / release message immediately after completing random access (S1190).

[0201] In both options 1 and 2 as described above, MN1 is configured, for example, to prepare RRC reconfiguration information based on the value of the SCG configuration status flag received in S1245.

[0202] In S1295, UE 10 stops timer T316 and performs the RRC reconfiguration procedure (in S1290) when it receives an RRC reconfiguration or RRC release message. Otherwise, if the timer expires, the UE performs a re-establishment of the source PCell.

[0203] Therefore, in combination with the above Figure 12 The target PSCell can provide RRC reconfiguration information to UE 10 immediately after completing random access. This reduces signaling overhead and speeds up MCG recovery.

[0204] Figure 13 As shown Figure 11 and 12 The example describes a flowchart of the processes performed by communication network control elements or functions (such as gNB1 20 acting as MN1 or gNB2 30 acting as SN1). That is, Figure 13A flowchart is shown relating to the processing performed by a communication network control element or function (such as gNB1 20 or gNB 30) that controls multi-connectivity communication in a communication network (such as a 3GPP-based network), in which at least two communication links are used for at least two different cells to form a communication path, and at least one of the at least two different cells is controlled by the communication network control element or function. For example, multi-connectivity involves a case where the first communication link is a link between a communication element or function established in the communication network and a primary cell (PCell) in a primary cell group (MCG), and the second communication link is a link between a communication element or function established in the communication network and a primary-secondary cell (PSCell) in a secondary cell group (SCG).

[0205] As mentioned above, the communication network can be based on 3GPP standards. However, according to other examples of the embodiments, other communication standards may also be used.

[0206] In 1310, when a link failure recovery process is performed for a first communication link to a first cell, and during this link failure recovery process, a conditional cell change process is performed for a second communication link to a second cell. During the conditional cell change process for the second communication link to the second cell, reconfiguration information regarding resource control for the first communication link is provided to the communication network control element or function controlling the target cell. The target cell may be controlled by the same communication network control element or function as the current second cell, or by a different communication network control element or function.

[0207] According to an example of an embodiment, the link failure recovery process is a primary cell group failure recovery process used to restore communication elements or functions with the primary cell in the primary cell group by using communication via a second communication link.

[0208] Furthermore, according to an example of the embodiment, the conditional cell change process includes: deattaching from a second cell currently used as a PSCell, and attaching to a new second cell ready to be used as a PSCell, wherein the new second cell is controlled by the same communication network control element or function as the second cell currently used as a primary / secondary cell (i.e., in the case of intra-SN), or by a different communication network control element or function (i.e., in the case of inter-SN).

[0209] According to some examples of the embodiments, when a link failure recovery process for a first communication link is initiated, Figure 13 The communication network control elements or functions involved in the processing control the second cell (i.e., SN1) that forms a communication path with it. When an indication of a successful conditional cell change is received from the target cell, reconfiguration information is provided.

[0210] Alternatively, according to some examples of the embodiments, when initiating a link failure recovery process for the first communication link, Figure 13 The communication network control elements or functions involved in the processing control the first cell (i.e., MN1) that forms a communication path with it.

[0211] According to some examples of embodiments, information on candidate cells indicating conditional cell changes for a second communication link to a second cell is stored. Furthermore, reconfiguration information regarding resource control for the first communication link is provided to each communication network control element or function controlling the candidate cells indicated in the stored information.

[0212] Furthermore, according to some examples of embodiments, information indicating whether reconfiguration information regarding resource control for the first communication link has a secondary cell group configuration is received and processed from a communication control element or function (e.g., from MN2) involved in the link failure recovery process of the first link. The received information is used to determine whether, during a conditional cell change process for the second communication link to the second cell (i.e., to SN2), reconfiguration information regarding resource control for the first communication link is provided to the communication network control element or function controlling the target cell. That is, MN2 can, for example, send SCG_config_status (see also...) Figure 12 Indicate to MN1 whether it has configured SCG.

[0213] Figure 14 It shows the combination as follows Figure 11 and Figure 12 The described embodiments are schematic diagrams of communication network control elements or functions (such as gNB1 20 or gNB2 30) configured to perform multi-connection communication of communication elements or functions in a communication network according to examples of embodiments of the present disclosure. It should be noted that the network element or function (such as gNB) may include other elements or functions besides those described below. Furthermore, even when referring to a network element or function, it may be another device or function with a similar task, such as a chipset, chip, module, application, etc., which may be part of a network element or attached to a network element as a separate element. It should be understood that each block and any combination thereof can be implemented by various components or combinations thereof, such as hardware, software, firmware, one or more processors and / or circuitry.

[0214] Figure 14The communication network control element or function 20 shown may include processing circuitry, processing functions, control units, or processor 201 (such as a CPU), adapted to execute instructions given by programs related to the control process. Processor 201 may include one or more processing portions or functions dedicated to a specific process as described below, or the process may run in a single processor or processing function. The portion used to perform such a specific process may also be provided as a discrete element or within one or more other processors, processing functions, or processing portions, such as in a physical processor like a CPU or in one or more physical or virtual entities. Reference numerals 202 and 203 denote input / output (I / O) units or functions (interfaces) connected to processor or processing function 201. I / O unit 202 may be used to communicate with communication elements or functions (such as UE10). I / O unit 203 may be used to communicate with network portions located on the communication network (e.g., other gNBs, core networks, etc.). I / O units 202 and 203 may be combined units including communication devices facing several entities, or may include a distributed structure having multiple different interfaces for different entities. Reference numeral 204 is an example of a memory that can be used to store data and programs to be executed by the processor or processing function 201 and / or as a working storage device for the processor or processing function 201. It should be noted that memory 204 can be implemented using one or more memory portions of the same or different types of memory.

[0215] The processor or processing function 201 is configured to perform processing related to the aforementioned control process. Specifically, the processor or processing circuit or function 201 includes at least the following sub-parts 2011, which are processing portions that can be used to provide reconfiguration information. Part 2011 can be configured to perform processing according to... Figure 13 The processing of S1310.

[0216] In the examples of the above embodiments, different concepts have been described for addressing the problem of performing a cell change procedure (such as a CPC procedure) for a secondary cell link during an ongoing link failure recovery process on the primary cell link. One method is described in which the UE performs timing control regarding CPC and / or MCG failure recovery (e.g., in conjunction with...). Figures 4 to 9 It also describes another approach that makes CPC execution more efficient in terms of signaling and latency (e.g., by combining...). Figures 11 to 13 According to further examples of the embodiments, these measures can also be combined. Specifically, in cases where timing control causes CPC execution, such as by combining... Figure 4 , 5 The possibility of repeated signaling during CPC execution, as discussed in points 6 and 8, can be considered in conjunction with, for example, Figure 11 and 12 The described example measures are used to improve the efficiency of signaling during the CPC process.

[0217] As described above, the measures discussed in the examples of the embodiments can provide a solution that ensures the UE has sufficient time to complete the CPC and recover the PCell via the target PSCell. Furthermore, when the UE deems waiting for RRC reconfiguration or RRC release from the source PSCell pointless or unlikely to succeed, early termination of the timer (e.g., T316) can be allowed. Additionally, an improved procedure can be provided to reduce signaling overhead and latency when recovering the MCG from the target PSCell. Furthermore, improved robustness and shorter UE downtime can be achieved.

[0218] It should be noted that the examples of embodiments of this disclosure are applicable to a variety of different network configurations. In other words, the examples shown in the above figures, which serve as the basis for the above examples, are merely illustrative and do not limit this disclosure in any way. That is, additional existing and proposed new functionalities available in the corresponding operating environment can be used based on the defined principles combined with the examples of embodiments of this disclosure.

[0219] According to a further example of the embodiments, for instance, an apparatus is provided for use by a communication element or function configured to perform multi-connection communication in a communication network, wherein at least two communication links are used to form communication paths by at least two different cells formed by at least one network element or function. The apparatus includes: components configured to determine to perform a link failure recovery process for a first communication link to a first cell; components configured to detect that conditions are met for performing a conditional cell change process for a second communication link to a second cell, the conditional cell change process being performed during the link failure recovery process for the first communication link; components configured to perform processing for controlling the timing of at least one of the link failure recovery process for the first communication link and the conditional cell change process for the second communication link; and components configured to perform at least one of the link failure recovery process and the conditional cell change process based on the result of the processing for controlling the timing.

[0220] Furthermore, according to some other examples of the embodiments, the apparatus defined above may further include methods for performing the above-described methods (e.g., according to the combination). Figure 9 The method described herein is a component of at least one of the processes defined in the process.

[0221] According to a further example of the embodiments, for instance, an apparatus is provided for use by a communication network control element or function configured to control multiple connection communications of communication elements or functions in a communication network, wherein at least two communication links are used for at least two different cells to form a communication path, and at least one of the at least two different cells is controlled by the communication network control element or function. The apparatus includes: a component configured to perform a conditional cell change process for a second communication link to a second cell when performing a link failure recovery process for a first communication link to a first cell, and during the link failure recovery process, to provide reconfiguration information regarding resource control for the first communication link to the communication network control element or function controlling the target cell during the conditional cell change process for the second communication link to the second cell.

[0222] Furthermore, according to some other examples of the embodiments, the apparatus defined above may further include methods for performing the above-described methods (e.g., according to the combination). Figure 13 The method described herein is a component of at least one of the processes defined in the process.

[0223] According to a further example of the embodiments, a non-transitory computer-readable medium including program instructions is provided, the program instructions being configured to cause a device, when performing multi-connection communication in a communication network in which at least two communication links are used to form communication paths in at least two different cells formed by at least one network element or function, perform at least the following processes: determining to perform a link failure recovery process for a first communication link with a first cell; detecting that conditions are met for performing a conditional cell change process for a second communication link to a second cell, the conditional cell change process being to be performed during the link failure recovery process for the first communication link; performing processing for controlling the timing of at least one of the link failure recovery process for the first communication link and the conditional cell change process for the second communication link; and performing at least one of the link failure recovery process and the conditional cell change process based on the result of the processing for controlling the timing.

[0224] According to a further example of the embodiment, a non-transitory computer-readable medium including program instructions is provided for causing a device to perform at least the following processes when performing multi-connection communication controlling a communication element or function in a communication network in which at least two communication links are used by at least two different cells to form a communication path (at least one of the at least two different cells is controlled by a communication network control element or function): when performing a link failure recovery process for a first communication link to a first cell, and during the link failure recovery process performing a conditional cell change process for a second communication link to a second cell, wherein during the conditional cell change process for the second communication link to the second cell, reconfiguration information regarding resource control for the first communication link is provided to a communication network control element or function controlling the target cell.

[0225] It should be understood that:

[0226] - The access technology used in a communication network to transmit services to and from entities can be any suitable existing or future technology, such as WLAN (Wireless Local Access Network), WiMAX (Global Microwave Access Interoperability), LTE, LTE-A, 5G, Bluetooth, infrared, etc.; in addition, wired technologies can also be applied in the embodiments, such as IP-based access technologies, such as wired networks or fixed lines.

[0227] - An embodiment suitable for implementation as software code or as part thereof and used to run with a processor or processing capabilities is independent of the software code and can be specified using any known or future-developed programming language (such as high-level programming languages ​​such as Objective-C, C, C++, C#, Java, Python, Javascript, other scripting languages, etc., or low-level programming languages ​​such as machine language or assembler).

[0228] - The implementation of the embodiments is hardware-independent and can be implemented using any known or future-developed hardware technology (such as microprocessors or CPUs (central processing units), MOS (metal-oxide-semiconductor), CMOS (complementary MOS), BiMOS (bipolar MOS), BiCMOS (bipolar CMOS), ECL (emitter-coupled logic), and / or TTL (transistor-transistor logic)) or any combination thereof.

[0229] - Implementations can be carried out as individual devices, apparatuses, units, components or functions, or in a distributed manner. For example, one or more processors or processing functions can be used or shared in a process / process, or one or more processing segments or processing portions can be used and shared in a process / process, wherein one or more physical processors can be used to implement one or more processing portions dedicated to a particular process / process as described.

[0230] The device can be implemented by a semiconductor chip, a chipset, or a (hardware) module that includes such a chip or chipset.

[0231] - The implementation can also be carried out as any combination of hardware and software, such as ASIC (Application-Specific Integrated Circuit) components, FPGA (Field-Programmable Gate Array) or CPLD (Complex Programmable Logic Device) components or DSP (Digital Signal Processor) components.

[0232] - The embodiments can also be implemented as computer program products, including a computer-usable medium in which computer-readable program code is embodied, the computer-usable program code being adapted to perform the processes / procedures as described in the embodiments, wherein the computer-usable medium may be a non-transitory medium.

[0233] Although this disclosure has been described herein with reference to specific embodiments thereof, it is not limited thereto and various modifications may be made thereto.

Claims

1. An apparatus for use by a communication element or function configured to perform multi-connection communication in a communication network, wherein at least two communication links are used by at least two different cells formed by at least one network element or function to form a communication path, the apparatus comprising: At least one processing circuit, and At least one memory for storing instructions to be executed by the processing circuit. Wherein, the at least one memory and the instructions are configured, together with the at least one processing circuit, to cause the device to at least: Determine whether to execute a link failure recovery procedure for the first communication link with the first cell. The detection confirms that the conditions for performing a conditional cell change procedure for a second communication link to a second cell are met, the conditional cell change procedure to be performed during the link failure recovery procedure for the first communication link. Execute timing processing for controlling at least one of the link fault recovery process for the first communication link and the conditional cell change process for the second communication link, and Based on the result of the processing used to control the timing, at least one of the link fault recovery process and the conditional cell change process is executed; Wherein, the at least one memory and the instructions are further configured, together with the at least one processing circuit, to cause the device to at least: When the link failure recovery process is executed, a first timer is started, which indicates the time period for initiating the connection reconstruction process for the first communication link to the first cell; In the processing for controlling the timing of at least one of the link failure recovery process for the first communication link and the conditional cell change process for the second communication link, when it is detected that the condition for performing the conditional cell change process for the second communication link is met, the first timer is stopped and a second timer is started, the second timer indicating the time period for initiating the connection reconstruction process for the first communication link to the first cell.

2. The apparatus of claim 1, wherein, The at least one memory and the instructions are further configured, together with the at least one processing circuitry, to cause the device to at least: The system receives and processes at least two different timer values ​​for the first timer from a communication network control element or function that controls at least one of the first and second cells, wherein one of the at least two different timer values ​​is applied to the first timer to indicate the time period for initiating the connection reconstruction process for the first communication link to the first cell. In the processing for controlling the timing of at least one of the link fault recovery process for the first communication link and the conditional cell change process for the second communication link, when the condition for performing the conditional cell change process for the second communication link to the second cell is detected to be satisfied, the first timer is stopped and the first timer is restarted, wherein another timer value of the at least two timer values ​​is applied to the first timer.

3. The apparatus of claim 1, wherein, The at least one memory and the instructions are further configured, together with the at least one processing circuitry, to cause the device to at least: Receives and processes at least two different timer values ​​for the first timer from a communication network control element or function that controls at least one of the first cell and the second cell. Whether a measurement report that could potentially lead to a conditional cell change process for the second communication link to the second cell is sent, and If the measurement report is sent, the longer of the at least two different timer values ​​is applied to the first timer for the time period in which the connection reconstruction process is initiated for the first communication link to the first cell.

4. The apparatus according to claim 1, wherein, The at least one memory and the instructions are further configured, together with the at least one processing circuitry, to cause the device to at least: Receives and processes a time value for the first timer and a predetermined threshold from a communication network control element or function that controls at least one of the first cell and the second cell, and In the processing for controlling the timing of at least one of the link fault recovery process for the first communication link and the conditional cell change process for the second communication link, the remaining time of the first timer is compared with the predetermined threshold. When the remaining time is greater than the predetermined threshold, the conditional cell change process for the second communication link to the second cell is executed, and when the remaining time is not greater than the predetermined threshold, the conditional cell change process for the second communication link to the second cell is skipped.

5. The apparatus according to claim 1, wherein, The at least one memory and the instructions are further configured, together with the at least one processing circuitry, to cause the device to at least: In the processing of timing for controlling at least one of the link fault recovery process for the first communication link and the conditional cell change process for the second communication link, when it is detected that the condition for executing the conditional cell change process for the second communication link to the second cell is met, the first timer is stopped, the conditional cell change process for the second communication link to the second cell is skipped, and the connection reconstruction process for the first communication link to the first cell is started.

6. The apparatus according to claim 1, wherein, The at least one memory and the instructions are further configured, together with the at least one processing circuitry, to cause the device to at least: Receives and processes an indication from a communication network control element or function that controls at least one of the first and second cells regarding whether a delayed conditional cell change process has been set, and In the processing for controlling the timing of at least one of the link fault recovery process for the first communication link and the conditional cell change process for the second communication link, when the conditional cell change process is delayed, the conditional cell change process for the second communication link to the second cell is executed, the first timer is stopped, and a second timer is started to indicate the time period for initiating the connection reconstruction process for the first communication link to the first cell.

7. The apparatus according to any one of claims 1 to 6, wherein, The at least one memory and the instructions are further configured, together with the at least one processing circuitry, to cause the device to at least: When the link failure recovery process for the first communication link with the first cell is performed, an indication that a link failure exists in the first communication link with the first cell is sent to the communication network control element or function controlling the second cell, wherein the indication includes information that a conditional cell change process is configured to be executed by the communication element or function.

8. The apparatus according to any one of claims 1 to 6, wherein, The first communication link is a link between the communication element or function established in the communication network and the primary cell in the primary cell group, and the second communication link is a link between the communication element or function established in the communication network and the primary and secondary cells in the secondary cell group.

9. The apparatus according to claim 8, wherein, The link failure recovery process is a primary cell group failure recovery process used to restore the communication element or function of the link with the primary cell in the primary cell group by using communication via the second communication link.

10. A method for use in a communication element or function configured to perform multi-connection communication in a communication network, wherein at least two communication links are used to form communication paths by at least two different cells formed by at least one network element or function, the method comprising: Determine whether to execute a link failure recovery procedure for the first communication link with the first cell. The detection confirms that the conditions for performing a conditional cell change procedure for a second communication link to a second cell are met, the conditional cell change procedure to be performed during the link failure recovery procedure for the first communication link. Execute timing processing for controlling at least one of the link fault recovery process for the first communication link and the conditional cell change process for the second communication link, and Based on the result of the processing used to control the timing, at least one of the link fault recovery process and the conditional cell change process is executed; The method further includes: When the link failure recovery process is executed, a first timer is started, which indicates the time period for initiating the connection reconstruction process for the first communication link to the first cell; In the processing for controlling the timing of at least one of the link failure recovery process for the first communication link and the conditional cell change process for the second communication link, when it is detected that the condition for performing the conditional cell change process for the second communication link is met, the first timer is stopped and a second timer is started, the second timer indicating the time period for initiating the connection reconstruction process for the first communication link to the first cell.

11. The method of claim 10, further comprising: Receives and processes a time value for the first timer and a predetermined threshold from a communication network control element or function that controls at least one of the first cell and the second cell, and In the processing for controlling the timing of at least one of the link fault recovery process for the first communication link and the conditional cell change process for the second communication link, the remaining time of the first timer is compared with the predetermined threshold. When the remaining time is greater than the predetermined threshold, the conditional cell change process for the second communication link to the second cell is executed, and when the remaining time is not greater than the predetermined threshold, the conditional cell change process for the second communication link to the second cell is skipped.

12. The method according to any one of claims 10 to 11, further comprising: When the link failure recovery process for the first communication link with the first cell is performed, an indication that a link failure exists in the first communication link with the first cell is sent to the communication network control element or function controlling the second cell, wherein the indication includes information that a conditional cell change process is configured to be executed by the communication element or function.

13. The method according to any one of claims 10 to 11, wherein, The first communication link is a link between the communication element or function established in the communication network and the primary cell in the primary cell group, and the second communication link is a link between the communication element or function established in the communication network and the primary and secondary cells in the secondary cell group.

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