Node device and method executed by same

Abstract

Various embodiments of the present disclosure propose a method performed by a third node in a communication system, the method comprising: receiving a first message from a second node, the first message comprising first information related to one or more candidate cells configured to a first node, and / or second information relating to a base station serving the one or more candidate cells, and sending to a second node a second message comprising third information relating to one or more candidate cells configured to the first node that are admitted or not admitted by a third node, the first message is used for requesting to prepare a target cell switched by the first node.

Description

Technical Field

[0001] The present disclosure relates to the field of communications, and more particularly, to a method performed by a third node, a method performed by a second node, a method performed by a fifth node, a method performed by a fourth node, a third node, a second node, a fifth node, and a fourth node. Background Art

[0002] In order to meet the increasing demand for wireless data communication services since the deployment of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems. Thus, 5G or pre-5G communication systems are also referred to as "super 4G networks" or "post-LTE systems".

[0003] Wireless communication is one of the most successful innovations in modern history. Recently, the number of subscribers to wireless communication services has exceeded 5 billion and is continuing to grow rapidly. Due to the increasing popularity of smart phones and other mobile data devices (e.g., tablet computers, laptop computers, netbooks, e-book readers, and machine type devices) among consumers and enterprises, the demand for wireless data services is growing rapidly. To meet the high growth of mobile data services and support new applications and deployments, it is crucial to improve the efficiency and coverage of wireless interfaces. Summary of the Invention

[0004] According to one aspect of the present disclosure, there is provided a method performed by a third node in a communication system, the method comprising: receiving, from a second node, a first message comprising first information related to one or more candidate cells configured for a first node, and / or second information related to a base station serving the one or more candidate cells, and / or first resource request information for requesting resources, and sending, to the second node, a second message comprising third information related to one or more candidate cells configured for the first node that are accepted or not accepted by the third node, wherein the first message is for requesting a target cell or candidate cell for preparing a handover of the first node.

[0005] A method performed by a third node in a communication system according to the present disclosure, wherein the first message further includes at least one of the following: fourth information for requesting configuration of a target cell for handover of a first node; fifth information for requesting configuration of candidate cells for handover of a first node. A method performed by a third node in a communication system according to the present disclosure, wherein the first resource request information includes at least one of the following: resource request indication information, identification information of a base station, identification information of a distributed unit, identification information of a cell, service user number information, carrier indication information, index of a preamble signal, synchronization signal index information, physical random access channel mask index; the fourth information includes at least one of the following: identification information of a target cell, first resource configuration information, configuration information for the third node to generate measurements of candidate cells within the target cell; the fifth information includes at least one of the following: information related to layer 1 / layer 2 triggered mobility LTM handover; first configuration identification information for identifying the configuration corresponding to a candidate cell; identification information of a first candidate cell for identifying the candidate cell for handover of a first node; second resource configuration information for the third node to generate measurements of other candidate cells within the candidate cell for handover of a first node, second resource request information for requesting resources of the third node.

[0006] A method performed by a third node in a communication system according to the present disclosure, wherein the third information includes at least one of the following: identification information of a second candidate cell for identifying the candidate cell accepted or not accepted by the third node; second configuration identification information for identifying the configuration corresponding to the candidate cell accepted or not accepted by the third node; first user identification information, information related to the identification used when the first node accesses the base station of the cell it is in; sixth information, including the configuration of the candidate cell accepted or not accepted by the third node; first configuration request information for requesting the second node to provide configuration information of the candidate cell identified by the identification information of the second candidate cell or the second configuration identification information.

[0007] A method performed by a third node in a communication system according to the present disclosure, wherein the second message further includes at least one of the following: seventh information related to the configuration of the target cell for handover of a first node; eighth information related to the configuration of the candidate cell for handover of a first node.

[0008] A method performed by a third node in a communication system according to the present disclosure, wherein the method further includes: receiving a third message from a second node, the third message including ninth information related to the candidate cell accepted by the third node, and / or tenth information related to the base station serving the candidate cell accepted by the third node.

[0009] A method performed by a third node in a communication system according to the present disclosure, wherein the method further includes: sending to or receiving from a fifth node serving the candidate cell a fourth message, where the fourth message includes at least one of the following: second user identification information, including information related to identifying a first node on the third node and / or the fifth node; first release information, including information related to one or more candidate cells configured for the first node that need to be released; first update information, including information related to updated candidate cells configured for the first node.

[0010] A method performed by a third node in a communication system according to the present disclosure, wherein the method further includes: sending a fifth message to a fourth node, where the fifth message includes second update information, and the second update information includes information related to updated candidate cells configured for the first node, where the fourth node is a distributed unit (DU) and the third node is a central unit (CU).

[0011] A method performed by a third node in a communication system according to the present disclosure, wherein the first information, the sixth information, the eighth information, or the ninth information, the first update information, or the second update information further includes at least one of the following: third configuration identification information for identifying the configuration corresponding to the candidate cell; identification information of the third candidate cell for identifying the candidate cell configured for the first node; configuration information for the synchronization signal, including information related to the configuration of the synchronization signal of the candidate cell; radio resource control (RRC) configuration information; thirteenth information, including information related to whether the RRC configuration information is a complete configuration; configuration information for synchronization, which is configuration information for triggering the first node to obtain synchronization information of the candidate cell; configuration information for the beam, including information related to the beam used when the first node transmits a signal; resource configuration information of the reference signal, including information related to the resources of the reference signal of the candidate cell; configuration information related to the first reset, including information associated with operations related to determining the reset required for the third node when the cell of the first node changes; configuration information related to the first timing advance (TA) measurement, shared indication information, indication information shared by multiple user equipments, identification information of the user equipment, identification information of the cell, index of the preamble signal, carrier indication information, index of the synchronization signal, physical random access channel mask index, information on the usage time.

[0012] A method performed by a third node in a communication system according to the present disclosure, wherein the synchronization configuration information includes at least one of the following: configuration information related to a random access channel required for early synchronization; configuration information related to a random access channel without random access; configuration information related to early uplink synchronization; configuration information related to contention-free random access; configuration information related to a random access channel.

[0013] A method performed by a third node in a communication system according to the present disclosure, wherein the first reset-related configuration information includes at least one of the following: fourteenth information, including information related to a reset operation associated with a cell identified by the identification information of the third candidate cell; first cell identification information, including information related to a cell for which a layer 2 reset is not required when a cell change occurs at the first node; second cell identification information, including information related to a cell for which a layer 2 reset is required when a cell change occurs at the first node; wherein the first timing advance TA measurement-related configuration information includes at least one of the following: fifteenth information, including information related to the measurement behavior of the first node associated with a cell identified by the identification information of the third candidate cell; third cell identification information, including information related to a cell for which the first node does not need to perform a time advance measurement based on a user terminal when a cell change occurs at the first node; fourth cell identification information, including information related to a cell for which the first node needs to perform a time advance measurement based on a user terminal when a cell change occurs at the first node.

[0014] A method performed by a third node in a communication system according to the present disclosure, wherein the second information or the tenth information includes at least one of the following: sixteenth information, used to indicate whether the second node has configured a candidate cell for the first node or to request the third node to accept the candidate cell configured for the first node.

[0015] According to another aspect of the present disclosure, there is provided a method performed by a second node in a communication system, the method including: sending a first message to a third node, the first message including first information related to one or more candidate cells configured for a first node, and / or second information related to a base station serving the one or more candidate cells, and / or first resource request information for requesting resources, and receiving a second message from the third node, the second message containing third information related to whether the third node accepts or does not accept the one or more candidate cells configured for the first node, wherein the first message is used to request to prepare a target cell or candidate cell for the handover of the first node.

[0016] A method performed by a second node in a communication system according to the present disclosure, wherein the first message further includes at least one of the following: fourth information for requesting configuration of a target cell for handover of a first node; fifth information for requesting configuration of candidate cells for handover of a first node.

[0017] A method performed by a second node in a communication system according to the present disclosure, wherein the fourth information includes at least one of the following: identification information of the target cell; first resource configuration information for being used by a third node to generate configuration information related to measuring candidate cells within the target cell.

[0018] A method performed by a second node in a communication system according to the present disclosure, wherein the fifth information includes at least one of the following: information related to layer 1 / layer 2 triggered mobility LTM handover; first configuration identification information for identifying the configuration corresponding to the candidate cell; identification information of the first candidate cell for identifying the candidate cell for handover of the first node; second resource configuration information for being used by a third node to generate configuration information related to measuring other candidate cells within the candidate cell for handover of the first node.

[0019] A method performed by a second node in a communication system according to the present disclosure, wherein the third information includes at least one of the following: identification information of a second candidate cell for identifying the candidate cell accepted or not accepted by the third node; second configuration identification information for identifying the configuration corresponding to the candidate cell accepted or not accepted by the third node; first user identification information, information related to the identification used when the first node accesses the base station of the cell it is in; sixth information, including the configuration of the candidate cell accepted or not accepted by the third node; first configuration request information for requesting the second node to provide configuration information of the candidate cell identified by the identification information of the second candidate cell or the second configuration identification information.

[0020] A method performed by a second node in a communication system according to the present disclosure, wherein the second message further includes at least one of the following: seventh information related to the configuration of the target cell for handover of the first node; eighth information related to the configuration of the candidate cell for handover of the first node.

[0021] A method performed by a second node in a communication system according to the present disclosure, wherein the method further includes: sending a third message to a third node, the third message including ninth information related to the candidate cell accepted by the third node, and / or tenth information related to the base station serving the candidate cell accepted by the third node.

[0022] A method performed by a second node in a communication system according to the present disclosure, wherein the first information, the sixth information, the eighth information, or the ninth information further includes at least one of the following: third configuration identification information for identifying a configuration corresponding to a candidate cell; identification information of a third candidate cell for identifying a candidate cell configured for a first node; configuration information for synchronization signals, including information related to the configuration of synchronization signals of candidate cells; radio resource control (RRC) configuration information; thirteenth information, including information related to whether the RRC configuration information is a complete configuration; configuration information for synchronization, for triggering a first node to obtain synchronization information of a candidate cell; configuration information for beams, including information related to the beams used when the first node transmits signals; resource configuration information of reference signals, including information related to the resources of reference signals of candidate cells; first reset-related configuration information, including information associated with operations related to determining a reset required for a third node when a cell of the first node changes; first timing advance (TA) measurement-related configuration information.

[0023] A method performed by a second node in a communication system according to the present disclosure, wherein the configuration information for synchronization includes at least one of the following: configuration information related to a random access channel required for early synchronization; configuration information related to a random access channel without random access; configuration information related to early uplink synchronization; configuration information related to contention-free random access; configuration information related to a random access channel.

[0024] A method performed by a second node in a communication system according to the present disclosure, wherein the first reset-related configuration information includes at least one of the following: fourteenth information, including information related to a reset operation associated with the cell identified by the identification information of the third candidate cell; first cell identification information, including information related to a cell for which a layer 2 reset is not required when a cell change occurs in the first node; second cell identification information, including information related to a cell for which a layer 2 reset is required when a cell change occurs in the first node; wherein the first timing advance (TA) measurement-related configuration information includes at least one of the following: fifteenth information, including information related to a measurement behavior of the first node associated with the cell identified by the identification information of the third candidate cell; third cell identification information, including information related to a cell for which the first node does not need to perform a measurement of the time advance based on a user terminal when a cell change occurs in the first node; fourth cell identification information, including information related to a cell for which the first node needs to perform a measurement of the time advance based on a user terminal when a cell change occurs in the first node.

[0025] A method performed by a second node in a communication system according to the present disclosure, wherein the second information or the tenth information includes at least one of the following: sixteenth information for indicating whether the second node has configured a candidate cell for the first node or for requesting the third node to admit the candidate cell configured for the first node.

[0026] A method performed by a second node in a communication system according to the present disclosure, wherein the method further includes: sending a sixth message to a fifth node, where the sixth message includes at least one of the following: third resource configuration information for the fifth node to generate configuration information related to measuring other candidate cells within a candidate cell; second release information, information related to one or more candidate cells configured for the first node that need to be released; eleventh information, configuration information related to the base station serving the first node; twelfth information, information related to one or more candidate cells configured for the first node.

[0027] A method performed by a second node in a communication system according to the present disclosure, wherein the eleventh information includes at least one of the following: identification information of the base station; identification information of the cell; third user identification information, information related to the identification used by the first node when accessing the base station.

[0028] A method performed by a second node in a communication system according to the present disclosure, wherein the method further includes: when the second node includes a central unit and a distributed unit, the central unit of the second node receives a third request message sent by the distributed unit of the second node for requesting resources for sending a random access preamble signal, and the central unit of the second node sends a third response message for resource allocation to the distributed unit of the second node; the third request message includes at least one of the following: identification information of the cell, carrier indication information, synchronization signal index information; and the third response message includes at least one of the following: index of the preamble signal, physical random access channel mask index

[0029] A method performed by a second node in a communication system according to the present disclosure, wherein the method further includes: sending a fifth message to a fourth node, where the fifth message includes second update information, and the second update information includes information related to one or more updated candidate cells configured for the first node, where the fourth node is a distributed unit DU and the third node is a central unit CU.

[0030] According to another aspect of the present disclosure, there is provided a method performed by a fifth node in a communication system, the method including: receiving a sixth message from a second node; and / or receiving a fourth message from a third node, where the sixth message or the fourth message includes information related to the update of a candidate cell.

[0031] A method performed by a fifth node in a communication system according to the present disclosure, wherein the sixth message includes at least one of the following: third resource configuration information for the fifth node to generate configuration information related to measuring other candidate cells within a candidate cell; second release information, information related to one or more candidate cells configured for a first node that need to be released; eleventh information, configuration information related to a base station serving the first node; twelfth information, information related to one or more candidate cells configured for the first node.

[0032] A method performed by a fifth node in a communication system according to the present disclosure, wherein the fourth message includes at least one of the following: second user identification information including information related to identifying a first node on a third node and / or a fifth node; first release information including information related to one or more candidate cells configured for the first node that need to be released; first update information including information related to updated one or more candidate cells configured for the first node.

[0033] According to another aspect of the present disclosure, there is provided a method performed by a fourth node in a communication system, the method including: receiving a fifth message from a second node; and / or receiving a fifth message from a third node, wherein the fifth message includes second update information, and the second update information includes information related to updated one or more candidate cells configured for a first node.

[0034] A method performed by a fourth node in a communication system according to the present disclosure, wherein the second update information further includes at least one of the following: third configuration identification information for identifying a configuration corresponding to a candidate cell; identification information of a third candidate cell for identifying a candidate cell configured for a first node; configuration information for a synchronization signal including information related to a configuration of a synchronization signal of a candidate cell; radio resource control (RRC) configuration information; thirteenth information including information related to whether the RRC configuration information is a complete configuration; configuration information for synchronization for triggering a first node to obtain synchronization information of a candidate cell; configuration information for a beam including information related to a beam used when the first node transmits a signal; resource configuration information of a reference signal including information related to a resource of a reference signal of a candidate cell; first reset-related configuration information including information associated with an operation related to determining a reset required for a third node when a cell of the first node changes; first timing advance (TA) measurement-related configuration information.

[0035] According to another aspect of the present disclosure, there is provided a third node, which includes: a transceiver configured to transmit and receive signals with the outside; and a controller configured to control the transceiver to execute the method performed by the third node as described above.

[0036] According to another aspect of the present disclosure, there is provided a second node, which includes: a transceiver configured to transmit and receive signals with the outside; and a controller configured to control the transceiver to execute the method performed by the second node as described above.

[0037] According to another aspect of the present disclosure, there is provided a fifth node, which includes: a transceiver configured to transmit and receive signals with the outside; and a controller configured to control the transceiver to execute the method performed by the fifth node as described above.

[0038] According to another aspect of the present disclosure, there is provided a fourth node, which includes: a transceiver configured to transmit and receive signals with the outside; and a controller configured to control the transceiver to execute the method performed by the fourth node as described above.

[0039] According to another aspect of the present disclosure, there is provided a non-transitory computer-readable recording medium on which a program for executing any of the methods as described above when run by a computer is stored. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is an exemplary system architecture of System Architecture Evolution (SAE).

[0041] Figure 2 is an exemplary system architecture according to various embodiments of the present disclosure.

[0042] Figure 3 is a schematic diagram of interaction between a second node and a third node according to an embodiment of the present disclosure.

[0043] Figure 4 is a schematic diagram of interaction between a second node and a fifth node according to an embodiment of the present disclosure.

[0044] Figure 5 is a schematic diagram of interaction between a third node and a fifth node according to an embodiment of the present disclosure.

[0045] Figure 6 is a schematic diagram of interaction between a second node or a third node and a fourth node according to an embodiment of the present disclosure.

[0046] Figure 7 is a block diagram showing the structure of a third node according to an embodiment of the present disclosure.

[0047] Figure 8 is a block diagram showing the structure of a second node according to an embodiment of the present disclosure.

[0048] Figure 9 is a block diagram showing the structure of a fifth node according to an embodiment of the present disclosure.

[0049] Figure 10 is a block diagram showing the structure of a fourth node according to an embodiment of the present disclosure. Detailed Description

[0050] The following description with reference to the accompanying drawings is provided to facilitate a thorough understanding of various embodiments of the present disclosure defined by the claims and their equivalents. This description includes various specific details to facilitate understanding but should only be considered exemplary. Thus, those of ordinary skill in the art will recognize that various changes and modifications can be made to the various embodiments described herein without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and structures may be omitted for clarity and conciseness.

[0051] The terms and phrases used in the following specification and claims are not limited to their dictionary meanings but are used solely by the inventors to enable a clear and consistent understanding of the present disclosure. Thus, it should be apparent to those skilled in the art that the following description of the various embodiments of the present disclosure is provided for illustrative purposes only and not for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents.

[0052] It should be understood that the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more such surfaces.

[0053] The term "comprising" or "may comprise" refers to the presence of the corresponding disclosed function, operation, or component that can be used in various embodiments of the present disclosure, without limiting the presence of one or more additional functions, operations, or features. In addition, the term "comprising" or "having" can be interpreted to mean that certain characteristics, numbers, steps, operations, components, components, or combinations thereof are present, but should not be interpreted to exclude the possibility of the presence of one or more other characteristics, numbers, steps, operations, components, components, or combinations thereof.

[0054] The term "or" used in various embodiments of the present disclosure includes any of the recited terms and all combinations thereof. For example, "A or B" can include A, can include B, or can include both A and B.

[0055] Unless otherwise defined, all terms (including technical and scientific terms) used in this disclosure have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. As used in a dictionary, ordinary terms are interpreted to have a meaning consistent with the context in the relevant art field and should not be interpreted in an idealized or overly formal manner unless expressly so defined in this disclosure.

[0056] The following discussion Figures 1 to 10 and the various embodiments for describing the principles of this disclosure in this patent document are for illustration only and should not be construed in any way as limiting the scope of this disclosure. Those of ordinary skill in the art will understand that the principles of this disclosure can be implemented in any appropriately arranged system or device.

[0057] Figure 1 is an exemplary system architecture 100 of the System Architecture Evolution (SAE). The User Equipment (UE) 101 is a terminal device for receiving data. The Evolved Universal Terrestrial Radio Access Network (E-UTRAN) 102 is a radio access network that includes macro base stations (eNodeB / NodeB) providing access to the wireless network interface for the UE. The Mobility Management Entity (MME) 103 is responsible for managing the mobility context, session context, and security information of the UE. The Serving Gateway (SGW) 104 mainly provides user plane functions, and the MME 103 and the SGW 104 may be in the same physical entity. The Packet Data Network Gateway (PGW) 105 is responsible for functions such as charging and lawful interception and may also be in the same physical entity as the SGW 104. The Policy and Charging Rules Function entity (PCRF) 106 provides Quality of Service (QoS) policies and charging guidelines. The Serving GPRS Support Node (SGSN) 108 is a network node device in the Universal Mobile Telecommunications System (UMTS) that provides routing for data transmission. The Home Subscriber Server (HSS) 109 is the home subscription subsystem of the UE and is responsible for protecting user information including the current location of the user equipment, the address of the serving node, user security information, and the packet data context of the user equipment.

[0058] Figure 2 is an exemplary system architecture 200 according to various embodiments of this disclosure. Other embodiments of the system architecture 200 can be used without departing from the scope of this disclosure.

[0059] The user equipment (UE) 201 is a terminal device for receiving data. The next-generation radio access network (NG-RAN) 202 is a radio access network that includes base stations (gNB or eNB connected to the 5G core network 5GC, and the eNB connected to 5GC is also called ng-gNB) that provide an access wireless network interface for the UE. The access control and mobility management function entity (AMF) 203 is responsible for managing the mobility context and security information of the UE. The user plane function entity (UPF) 204 mainly provides the functions of the user plane. The session management function entity SMF205 is responsible for session management. The data network (DN) 206 includes services such as those of the operator, access to the Internet, and third-party services.

[0060] The text and the drawings are provided only as examples to assist in understanding the present disclosure. They should not be construed as limiting the scope of the present disclosure in any way. Although certain embodiments and examples have been provided, it will be apparent to those skilled in the art based on the content disclosed herein that the illustrated embodiments and examples can be changed without departing from the scope of the present disclosure.

[0061] Before introducing the specific content, some assumptions and definitions of the present invention are given below.

[0062] In the present invention, the message names are only examples, and other message names can also be used.

[0063] In the message names of the present invention, the "first", "second", etc. included are only examples of the messages and do not represent the execution order.

[0064] In the present invention, the detailed description of the steps irrelevant to the present invention is omitted.

[0065] In the present invention, the steps in each process can be executed in combination with each other or separately. The execution steps of each process are only examples and do not exclude other possible execution orders.

[0066] In the present invention, the base station can be a 6G base station, a 5G base station (such as gNB, ng-eNB), a 4G base station (such as eNB), or other types of access nodes.

[0067] In the present invention, when the cell accessed by the user equipment changes from one cell to another cell, this behavior can be called handover or cell switch. In the following description, handover and cell switch have the same meaning.

[0068] In the present invention, user, user equipment, user terminal, and user terminal device are equivalent.

[0069] In the present invention, the synchronization information may include, for example, at least one of the following information:

[0070] Downlink synchronization information;

[0071] Uplink synchronization information, such as timing advance information.

[0072] Nodes involved in the present invention:

[0073] The first node: a user terminal device. For example, the device may be a mobile phone or a relay node.

[0074] The second node: a base station, or a central unit of a base station, or a control plane part of a central unit of a base station. For example, it may be a source base station, or a central unit of a source base station, or a control plane part of a central unit of a source base station.

[0075] The third node: a base station, or a central unit of a base station, or a control plane part of a central unit of a base station. For example, it may be a target base station, or a central unit of a target base station, or a control plane part of a central unit of a target base station.

[0076] The fourth node: for example, it may be a distributed unit of a target base station. The distributed unit may be a distributed unit where the target cell is located, or a distributed unit where a candidate cell for handover is located, or a distributed unit where the source cell is located. The target cell is a special cell (SpCell, special cell). In one example, the special cell may be a special cell of a master cell group (SpCell of a master cell group) or a primary cell (PCell, Primary cell). In another example, the special cell may be a special cell of a secondary cell group or a primary / secondary cell (PSCell: source primary / secondary cell group cell).

[0077] The fifth node: a base station, or a central unit of a base station, or a control plane part of a central unit of a base station. For example, this node is a node that serves as a candidate cell configured for the user terminal device.

[0078] In one example, the second node and the third node may be the same node.

[0079] The base stations involved in the above second / third / fifth nodes may be, for example, one of the following types (other types that can be used for user terminal access are not excluded):

[0080] LTE base stations;

[0081] 5G base stations;

[0082] n 6G base station;

[0083] n NTN base station;

[0084] n HAPS base station;

[0085] n Drone base station;

[0086] n WIFI access point.

[0087] n The numbers of the following steps do not represent the order of step execution. The following steps can be executed independently or in combination with each other.

[0088] In the present invention, during the movement of the user terminal (the first node), the base station will configure two different types of cells for the first node:

[0089] n Target cell: This cell is the target cell for layer 3 handover.

[0090] n Candidate cell: This cell is a cell prepared for the user terminal for handover (or cell change). In one example, this cell is a candidate cell for layer 1 / layer 2 triggered mobility (LTM) cell change.

[0091] In a mobile network, the user equipment will perform handovers between different cells. During the handover process, the user equipment will experience communication interruptions. The main reason for the interruption is that the user equipment needs to perform measurements for a long time. Before the handover, the network side needs to perform signaling interactions between different nodes to determine the target cell and the configuration of the target cell, and then send a handover command to the user equipment. After that, the user equipment also needs to perform uplink and downlink synchronization with the network. During this process, the time required for the user to change cells is relatively long, which affects the performance of the user during movement. Therefore, it is necessary to enhance the handover process of the user equipment.

[0092] In some embodiments, when the user equipment is moving, the network side will configure the user equipment to perform a cell handover. One handover method is the handover based on layer 3 signaling, that is, the base station sends layer 3 signaling (layer 3 handover command) to the user equipment. After receiving this signaling, the user equipment interrupts the communication with the source cell and starts the process of accessing the target cell. During this process, there will be an interruption in the communication of the user equipment. In order to reduce the latency or communication interruption of the user terminal during the handover process, a cell handover method based on layer 1 / layer 2 signaling, namely LTM, has been proposed. Specifically, during the LTM cell change process, the network side will trigger the user terminal to perform a handover through layer 1 or layer 2 signaling. Further, before triggering the user terminal to perform a handover, the user terminal can also be allowed to obtain the time advance information required for accessing the target cell in advance, such as through the measurement of the user terminal, or by sending a random access signal in advance.

[0093] How to configure the cell change triggered by layer 1 (L1: Layer 1) / layer 2 (L2: Layer 2) signaling when configuring layer 3 (L3: Layer 3) handover is an urgent problem to be solved. In addition, when configuring the candidate cells of LTM, resources for the user equipment to access the candidate cells, such as random access resources, also need to be allocated. How to improve the efficiency of resource allocation is also an urgent problem to be solved.

[0094] Embodiments of the present disclosure provide a method executed by a third node in a communication system. The method includes: receiving a first message from a second node, the first message including first information related to one or more candidate cells configured for a first node, and / or second information related to the base station serving the one or more candidate cells, and / or first resource request information for requesting resources, and sending a second message to the second node, the second message including third information related to one or more candidate cells configured for the first node that the third node accepts or does not accept, wherein the first message is used to request to prepare a target cell or candidate cells for the handover of the first node.

[0095] Embodiments of the present disclosure provide a method executed by a second node in a communication system. The method includes: sending a first message to a third node, the first message including first information related to one or more candidate cells configured for a first node, and / or second information related to the base station serving the one or more candidate cells, and / or first resource request information for requesting resources, and receiving a second message from the third node, the second message including third information related to one or more candidate cells configured for the first node that the third node accepts or does not accept, wherein the first message is used to request to prepare a target cell or candidate cells for the handover of the first node.

[0096] In the above manner, it is possible to configure both layer 3 handover and LTM (L1 / L2 triggered mobility) handover. For example, when a user equipment performs a handover based on layer 3 signaling, the network side can configure candidate cells for LTM for the user equipment. In this way, when the user equipment accesses the target cell, it can still perform cell change based on LTM in the target cell, thereby reducing the communication interruption of the user equipment during the handover process.

[0097] The following will describe in detail the method for configuring layer 3 handover and / or LTM handover provided by each embodiment of the present disclosure in conjunction with Figures 3 to 7 the following.

[0098] Figure 3 is a schematic diagram of the interaction between a second node and a third node according to an embodiment of the present disclosure. In one example, Figure 3 the shown process is for configuring L3 handover; in another example, Figure 3 the shown process is for configuring candidate cells (such as LTM candidate cells); in another example, Figure 3 the shown process is for both configuring L3 handover and configuring candidate cells (such as LTM candidate cells). The beneficial effect of this process is to configure a handover for the user to reduce communication interruption and reduce data transmission interruption caused by user movement. As Figure 3 shown: This process may include one or more of the following steps 1-1 to step 1-3:

[0099] Step 1-1: The second node sends a first request message to the third node (for example, it can also be called the first message or other message names, and the present invention does not impose any restrictions on the message names). In one implementation manner, this message is used to configure the cell of the first node (user terminal). In one example, this cell may be the target cell for the handover of the first node (such as the target cell for layer 3 handover), and this target cell is the cell served by the third node. In another example, this cell may be a candidate cell (such as an LTM candidate cell), and this candidate cell is the cell served by the third node. After receiving this message, the third node will generate relevant configurations for the target cell or candidate cell, and then configure the first node (such as the second node configures the first node). This message may be a message associated with the user equipment, such as a handover request message (Handover Request). In another implementation manner, this message is used for the second node and the third node to interact resource allocation information, such as interacting with resource allocation information related to random access. This message may be a message not associated with the user equipment, such as a configuration update request message, an interface establishment request message, a resource allocation request message, etc. This message includes at least one of the following information:

[0100] n Target cell configuration request information (for example, it can also be referred to as the fourth information or other information names,

[0101] and the present invention does not impose any restrictions on the name of the information). This information is used to request the configuration of the target cell. In one example, the target cell is the target cell for a layer 3 handover. After receiving this information, the third node determines whether it can use this target cell as the target for the handover of the first node. If it can, the third node also prepares the resources for serving the first node and generates the configuration information for serving the first node. This information includes at least one of the following information:

[0102] n Identification information of the target cell, such as PCI (Physical Cell Identifier), NRCGI (new radio Cell Global Identifier), etc.

[0103] n First resource configuration information, which is used to help the third node generate the configuration information related to the measurement candidate cells in the target cell. In one example, this information is the configuration information of the CSI (Channel State Information) resource, which can help the third node generate the configuration information related to CSI measurement (such as measurement configuration information, measurement report configuration information). Further, this information can be the resource configuration information related to all candidate cells (such as LTM candidate cells) configured for the first node. Specifically, this information includes the identification information of the configuration of the candidate cell (configuration identification, or candidate identification), the resource information of the SSB (SS / PBCH block) of the candidate cell, and the index information of the SSB (SSBIndex). After receiving this information, the third node generates the configuration information for measuring these candidate cells according to the candidate cells configured for the first node (or according to the candidate cells acceptable to the third node).

[0104] n First resource request information, which is used to request the third node to allocate resources. One example of this resource is the random access resource, and another example is the non-random access

[0105] (RACH-less) resource, and another example is the early (uplink) synchronization (Early(UL)

[0106] Resources for

[0107] synchronization), and the requested resources can be used by the first node to trigger the user to send a random access signal, thereby obtaining random access information (such as time advance information). Further, this information can be used to request new resources, or to request an increase in new resources, or to request the release of resources. The beneficial effect of this information is that the third node can allocate resources according to the needs of the second node, improving the efficiency of resource utilization. This information includes at least one of the following information: n Resource request indication information, which is used to indicate a request for new resources, or to indicate a request to release already allocated resources, or to request an increase in new resources; this request indication information can be explicit information or implicit indication, such as determined by the name of the information (such as resource to be added, resource to be released); n Identification information of the base station, such as the identification information of the gNB

[0108] n Identification information of the distributed unit, such as the identification information of the distributed unit of the base station, the identification information of the gNB-DU (gNB distributed unit)

[0109] n Identification information of the cell, such as PCI, NR CGI, etc.; optionally, the identification information of the cell includes the identification information of the candidate cells configured for the UE.

[0110] n Service user number information, which indicates the number of users that the resources requested by the above-mentioned "first resource request information" need to serve. This user number can be an estimated information or an accurate information, and the third node will determine the amount of allocated resources based on this information. In an example, the resources requested by the above-mentioned "first resource request information" are shared by multiple users, and in the subsequent process, the second node will allocate resources to a user according to the request of the user or other nodes;

[0111] n Carrier indication information, which indicates the carrier where the requested resources are located, such as a normal uplink carrier (Normal UL carrier), a supplementary uplink carrier (Supplement UL carrier)

[0112] n Signal index information, which indicates the index of the allocated physical signal, such as the index of the preamble signal (Preamble Index)

[0113] ​​​​​​​n Synchronization signal index information, which indicates the index of the synchronization signal. In one example, the synchronization signal is an SSB (SS / PBCH block, PBCH: Physical Broadcast Channel), and then the index information is the SSB Index

[0114] n Index information of a resource, which indicates the index information of the requested resource. In one example, the index information is the Physical Random Access Channel Mask Index (PRACH Mask Index:

[0115] Physical Random Access Channel Mask Index) information;

[0116] n Candidate cell configuration request information (for example, it can also be called the fifth information or other information names,

[0117] the present invention does not impose any restrictions on the name of the information), which is used to request the configuration of candidate cells (such as LTM candidate cells). After receiving this information, the third node determines whether it can use this candidate cell as a candidate for the first node to switch to. If it can, the third node also prepares resources to serve the first node and generates configuration information for serving the first node. This information includes at least one of the following information:

[0118] n Information related to layer 1 / layer 2-triggered mobility LTM handover, such as a handover indication information, which indicates that the above candidate cell is used to configure LTM for the user, such as an LTM indicator (LTM indicator)

[0119] n Configuration identification information (for example, it can also be called the first configuration identification information or other information names, the present invention does not impose any restrictions on the name of the information), which identifies the configuration corresponding to the candidate cell, such as an LTM configuration identification (LTM configuration identification), an LTM candidate identification (LTM candidate identification)

[0120] n Identification information of the candidate cell (for example, it can also be called the first candidate cell identification information or other information names, the present invention does not impose any restrictions on the name of the information), which is used to identify the candidate cell configured for the first node, such as PCI, NR CGI, etc.

[0121] n Second resource configuration information, which is used to help the third node generate configuration information related to measuring other candidate cells in the candidate cell. In one example, this information is CSI

[0122] (Channel State Information) Configuration information of resources, which can help a third node generate configuration information related to CSI measurement (such as measurement configuration information, measurement report configuration information). Further, this information can be resource configuration information related to all candidate cells (such as LTM candidate cells) configured for a first node. Specifically, this information includes the configuration identification information of the candidate cell (configuration identification, or candidate

[0123] identification), the resource information of the SSB (SS / PBCH block) of the candidate cell, and the SSB index information (SSB Index). After receiving this information, the third node will generate configuration information for measuring these candidate cells according to the candidate cells configured for the first node (or according to the candidate cells acceptable to the third node). Second resource request information, which is used to request resources from the third node. The description of this information can refer to the above "First resource request information".

[0124] The first auxiliary information of the nth cell (for example, it can also be called the second information or other information names, and the present invention does not impose any restrictions on the names of the information). This information indicates the auxiliary information used to help the third node determine the cell configuration. In one example, the cell can be a candidate cell configured for the first node. In another example, the cell can be a target cell configured for the first node. In another example, the cell can be the serving cell of the first node. The beneficial effect of this information is:

[0125] Help the third node learn about the base station of the cell serving the first node and facilitate the third node to perform cell configuration update with this base station. When the first node accesses the third node, it can reduce communication interruption during the subsequent movement of the first node. This information includes at least one of the following information:

[0126] The nth cell configuration indication information (for example, it can also be called the sixteenth information or other information names, and the present invention does not impose any restrictions on the names of the information). One possible role of this information is to indicate whether candidate cells are configured for the first node, and another possible role is to request the third node to accept the candidate cells configured for the first node. After receiving this information, the third node can decide whether to accept the candidate cells configured for the first node.

[0127] Information related to a base station, the function of which is to indicate configuration information related to the base station of a candidate cell, a target cell, or a serving cell. After receiving this information, the third node can perform signaling interaction with this base station according to this information, so as to perform subsequent configuration (for example, when a user accesses the target cell or candidate cell served by the third node, the third node performs configuration update of the candidate cell with the base station of the candidate cell. See the signaling interaction process in steps 2-1 and 2-2 below).

[0128] This information includes at least one of the following information:

[0129] The identification information of the base station where the cell is located (such as the fifth node);

[0130] The identification information of the cell, such as PCI, NR CGI, etc.; Optionally, the identification information of the cell includes the identification information of the candidate cell configured for the UE.

[0131] The identification information of the user equipment. In one example, this information indicates the identification information used by the first node to access the base station of the cell where it is located, such as the identification information of the air interface (C-RNTI), the identification information of the interface of the base station (such as XnAP UE ID, and further, this ID is the identification information of the first node on the fifth node side). When the third node performs signaling interaction with the base station where the cell is located, the third node can include this identification information in the signaling, and then the base station where the cell is located can find the context of the first node according to this information, so as to perform cell configuration update. In one example, this identification can be named context ID or other names.

[0132] (C-RNTI), the identification information of the interface of the base station (such as XnAP UE ID, and further, this ID is the identification information of the first node on the fifth node side). When the third node performs signaling interaction with the base station where the cell is located, the third node can include this identification information in the signaling, and then the base station where the cell is located can find the context of the first node according to this information, so as to perform cell configuration update. In one example, this identification can be named context ID or other names.

[0133] The first configuration information of the candidate cell (for example, it can also be called the first information or other information names).

[0134] The present invention does not impose any restrictions on the name of the information), which is used to provide configuration information related to one or more candidate cells configured for the first node (in one example, the candidate cell is a candidate cell for LTM). In one example, when configuring a candidate cell for the first node (such as when the above "candidate cell configuration request information" is included in the first request message), this information is used to provide information about other candidate cells configured for the first node to the third node; in another example, when configuring a target cell for the first node (such as when the first request message includes the above "target cell configuration request information"), this information provides information about the candidate cells configured for the first node. After receiving this information, the third node can learn about the candidate cells configured for the first node, so as to determine the LTM cell change that occurs after the first node accesses the target cell or candidate cell. This information may include the configuration information of one or more candidate cells, that is, this information can be a list. In one example, this information can be included in the first request message in the form of a container, and this container contains the configuration information related to all candidate cells configured for the first node, such as LTM configuration (LTM

[0135] configuration (LTM-config)). In another example, this information can be included in the container of handover preparation information, and this container contains the configuration information related to all candidate cells configured for the first node, such as LTM configuration (LTM-config). In another example, this information can be included in the above first request message in the form of a displayed cell. The beneficial effect of this information is: to help the third node obtain the information about the candidate cells configured for the first node, and then the third node can configure the first node to perform cell handover, reducing communication interruption. For a candidate cell, this information includes at least one of the following information (in one example, the configuration information for a candidate cell can be included in the LTM Candidate cell):

[0136] n Configuration identification information (for example, it can also be called the third configuration identification information or other information names, and the present invention does not impose any restrictions on the name of the information), which identifies the configuration corresponding to the candidate cell, such as LTM configuration identification, LTM candidate identification

[0137] The identification information of the n candidate cells (for example, it can also be called the identification information of the third candidate cell or other information names, and the present invention does not impose any restrictions on the name of the information), which indicates the candidate cells configured for the first node, such as PCI, NR CGI, etc.

[0138] The configuration information of the synchronization signal, which indicates the configuration information of the synchronization signal of the candidate cell.

[0139] In one example, this information is the configuration information of the SSB, such as the LTM SSB configuration (LTM SSB config), and this information can be used by the first node to perform layer 1 measurements on the candidate cell. Specifically, this information includes at least one of the following information: frequency information (such as SSB frequency (SSB Frequency)), subcarrier spacing information (such as subcarrier spacing), periodic information (SSB period (SSB periodicity)), position information (such as SSB position in burst), power information (such as SSB power), etc.

[0141] The RRC configuration information, such as the candidate configuration, such as the configuration information included in the RRC Reconfiguration message.

[0142] The indication information of the complete configuration (for example, it can also be called the thirteenth information or other information names, and the present invention does not impose any restrictions on the name of the information), which is information related to whether the RRC configuration information is a complete configuration. This information indicates whether the above-mentioned "RRC configuration information" is a complete configuration, such as the configuration complete indicator.

[0143] indicator).

[0144] The synchronization configuration information. In one example, this information is used by the third node to trigger the user terminal to obtain the synchronization information (such as time advance information) of the candidate cell. This information includes at least one of the following

[0145] information:

[0146] Configure the random access channel (RACH) required for early synchronization in advance, or configure the RACH without random access (RACH-less), or configure early uplink synchronization (Early UL synchronization configuration). This configuration information is used for the first node to obtain the synchronization information of the candidate cell (or send a random access signal to the candidate cell) before receiving a handover command (such as a command used to trigger the user to change the LTM cell, the LTM MAC control element (LTM MAC Control Element)). In one example, this information is the configuration information on the normal uplink carrier. In another example, this information is the configuration information on the supplementary uplink carrier. In another example, this information includes both the configuration information on the normal uplink carrier and the configuration information on the supplementary uplink carrier. For the normal uplink carrier or the supplementary uplink carrier, this information includes at least one of the following information:

[0147] ● Indication information in the frequency domain, which indicates the frequency domain information of the random access signal (such as the random access pilot signal preamble) sent by the first node, such as the frequency point of the normal uplink carrier, the frequency point of the supplementary uplink carrier, and the configuration information of the bandwidth part (BWP) (such as BWP ID);

[0148] ● Information related to the sequence, which indicates the sequence used for the sent random access signal, such as prach-RootSequenceIndex;

[0149] ● Time alignment timer, which indicates the valid time of the time advance, such as the time advance timer;

[0150] l RACH generic configuration, which indicates the general configuration information used for sending the random access signal. This information includes at least one of the following information: prach-configurationIndex random access channel configuration index information, the target power for the network receiver side to receive the preamble

[0151] preambleReceivedTargetPower, the maximum number of times to send the preamble

[0152] premableTransMax, the step size of the transmission power increase of the preamble

[0153] powerRampingSetp, the size of the random access response window

[0154] ra-ResponseWindow, etc.;

[0155] l RACH dedicated configuration, which indicates dedicated configuration information for sending random access signals. This information may vary for different users and includes at least one of the following: RACH occasion information (which indicates the resources for sending random access signals), the number of SSBs per RACH occasion (ssb-perRACH-occassion), resource configuration information (such as the mask index for random access resource selection, physical random access channel maskindex), the index of the corresponding SSB or CSI-RS (SSB / CSIRS-index), and the index of the preamble (ra-PreambleIndex);

[0156] l Configuration information related to contention free random access or RACH-based configuration information, which is used by the first node to obtain synchronization information of candidate cells (or send random access signals to candidate cells) when receiving a handover command (such as a command for triggering a user to change LTM cells, LTM MAC control element). In one example, when the first node receives a handover command (such as a command for LTM cell change), the first node sends a random access signal based on the information in the handover command to obtain synchronization information of the candidate cell (such as time advance). In one example, this information is configuration information on a normal uplink carrier. In another example, this information is configuration information on a supplementary uplink carrier. In another example, this information includes both configuration information on a normal uplink carrier and configuration information on a supplementary uplink carrier. For a normal uplink carrier or a supplementary uplink carrier, this information includes at least one of the following:

[0157] ● Frequency domain indication information;

[0158] ● Information related to sequences;

[0159] ● Time alignment timer;

[0160] l RACH generic configuration;

[0161] l RACH dedicated configuration.

[0162] For the specific description of the above information, reference can be made to the description of each piece of information in the above "Configuration of RACH Required for Early Synchronization".

[0163] n Configuration information of the beam, which indicates the beam used by the first node when sending a signal (such as a random access signal). This information includes at least one of the following:

[0164] u Indication information of the downlink beam, such as the Transmission Configuration Indication (TCI) state index.

[0165] u Indication information of the uplink beam, such as the TCI state index.

[0166] u Indication information of the uplink and downlink beams. In one example, this information is joint TCI state indication information, such as the TCI state index.

[0167] n Resource configuration information of the reference signal, which indicates the resources of the reference signal of the candidate cell.

[0168] This information includes at least one of the following:

[0169] u Configuration information of the resources of the CSI-RS (Channel State Information-Reference Signal);

[0170] u Configuration information of the resources of the NZP (Non-zero-power)-CSI-RS;

[0171] u Configuration information of the resources of the reference signal for path loss estimation, and the reference signal indicated by this information is used for path loss estimation.

[0172] n Configuration information related to the first reset, which helps the third node determine the reset-related operations required by the third node when the cell of the first node changes. This information includes at least one of the following:

[0173] The first indication information for not resetting the u-identifier (for example, it can also be called the fourteenth information or other information names, and the present invention does not impose any restrictions on the names of the information) is information related to the reset operation associated with the cell identified by the identification information of the third candidate cell, such as No Reset ID. This information can indicate the information of the reset operation associated with the cell indicated by the above "identification information of the candidate cell". In one example, this information is used to determine whether a layer 2 reset is required when the first node is triggered by the LTM cell change process (such as triggered by the third node or the first node on the selected cell). After receiving this information, the third node will determine whether a reset operation (such as whether to perform a layer 2 reset) is required based on the cell change of the first node (such as changing from the cell indicated by the above "identification information of the candidate cell" to another cell, or changing from another cell to the cell indicated by the above "identification information of the candidate cell". In one example, this other cell is a candidate cell of LTM, and in another example, this other cell is not a candidate cell of LTM) and this indication information. The beneficial effect of this information is to help the third node know whether the first node has performed a layer 2 reset, achieve the same behavior as the first node, and reduce the latency of the first node's cell change when the layer 2 reset is not performed.

[0174] The first cell identification information for no reset (for example, it can also be called the first cell identification information or other information names, and the present invention does not impose any restrictions on the names of the information) is information related to the cell for which no layer 2 reset is required when the first node undergoes a cell change. The cell indicated by this information can be the cell for which no layer 2 reset is required when the first node undergoes a cell change. In one embodiment, this cell is a candidate cell of LTM. In one example, if the cell of the first node changes from the cell indicated by this "first cell identification information for no reset" to the cell indicated by the above "identification information of the candidate cell", the third node does not need to perform a layer 2 reset; in another example, if the cell of the first node changes from the cell indicated by the above "identification information of the candidate cell" to the cell indicated by this "first cell identification information for no reset", the third node does not need to perform a layer 2 reset. The first cell identification information for reset required (for example, it can also be called the second cell identification information or other information names, and the present invention does not impose any restrictions on the names of the information) is information related to the cell for which a layer 2 reset is required when the first node undergoes a cell change. The cell indicated by this information can be the cell for which a layer 2 reset is required when the first node undergoes a cell change. In one embodiment, this cell is a candidate cell of LTM. In one example, if the cell of the first node changes from this "first cell identification information for reset required"

[0175] The indicated cell becomes the cell indicated by the above "identification information of the candidate cell", and the third node needs to perform a layer 2 reset; in another example, if the cell of the first node changes from the cell indicated by the above "identification information of the candidate cell" to the cell indicated by the "identification information of the first cell to be reset", the third node needs to perform a layer 2 reset.

[0176] n Configuration information related to the first timing advance TA measurement. In one example, this configuration information is used to indicate the measurement of the timing advance, such as the UE-based TA measurement. The role of this information is to help the third node determine whether the first node performs a timing advance measurement when the cell of the first node changes. This information includes at least one of the following information:

[0177] u The first indication information for identifying the TA measurement (for example, it can also be called the fifteenth information or other information names, and the present invention does not impose any restrictions on the information names), information related to the measurement behavior of the first node associated with the cell identified by the identification information of the third candidate cell, such as the UE-Measured TA ID. This information can indicate the measurement behavior of the first node related to the cell indicated by the above "identification information of the candidate cell" (such as performing UE-based timing advance measurement). In one example, this information is used to determine whether a UE-based timing advance measurement needs to be performed when the first node is executing the LTM cell change process (such as triggered by the third node or triggered by the first node on the selected cell) or before. After receiving this information, the third node will determine whether the first node performs a UE-based timing advance measurement based on the cell change of the first node (such as changing from the cell indicated by the above "identification information of the candidate cell" to another cell, or changing from another cell to the cell indicated by the above "identification information of the candidate cell". In one example, this other cell is a candidate cell of LTM, and in another example, this other cell is not a candidate cell of LTM) and this indication information. Further, it can be determined whether the third node triggers the first node to obtain the timing advance in advance. The beneficial effect of this information is to help the third node know whether the first node has performed a UE-based timing advance measurement, thereby optimizing resource allocation and avoiding the triggering of unnecessary early acquisition of the timing advance (or early uplink synchronization).

[0178] The first cell identification information without TA measurement (for example, it can also be called the third cell identification information or other information names, and the present invention does not impose any restrictions on the name of the information) is information related to the cell where the first node does not need to perform measurements based on the time advance of the user terminal when a cell change occurs. The cell indicated by this information can be the cell where the first node does not perform measurements based on the time advance of the user terminal when a cell change occurs. In one example, if the cell of the first node changes from the cell indicated by the "first cell identification information without TA measurement" to the cell indicated by the above "identification information of the candidate cell", the first node does not perform measurements based on the time advance of the user terminal; in another example, if the cell of the first node changes from the cell indicated by the above "identification information of the candidate cell" to the cell indicated by the "first cell identification information without TA measurement", the first node does not perform measurements based on the time advance of the user terminal.

[0179] The first cell identification information that requires TA measurement (for example, it can also be called the fifteenth information,

[0180] or other information names, and the present invention does not impose any restrictions on the name of the information) is information related to the cell where the first node needs to perform measurements based on the time advance of the user terminal when a cell change occurs. The cell indicated by this information can be the cell where the first node needs to perform measurements based on the time advance of the user terminal when a cell change occurs. In one example, if the cell of the first node changes from the cell indicated by the "first cell identification information that requires TA measurement" to the cell indicated by the above "identification information of the candidate cell", the first node needs to perform measurements based on the time advance of the user terminal; in another example, if the cell of the first node changes from the cell indicated by the above "identification information of the candidate cell" to the cell indicated by the "first cell identification information that requires TA measurement", the first node needs to perform measurements based on the time advance of the user terminal.

[0181] Step 1-2: The third node sends a first response message to the second node (for example, it can also be called the second message or other message names, and the present invention does not impose any restrictions on the message names). In one embodiment, this message is used to provide configuration information of the target cell or candidate cell, and this configuration information can be used to configure the first node for L3 handover or LTM. This message can be a message associated with the user equipment, such as a Handover Request Acknowledge message. In another embodiment, this message is used for the second node and the third node to interact with resource allocation information, such as interacting with resource allocation information related to random access. This message can be a message not associated with the user equipment, such as a configuration update response message, an interface establishment response message, a resource allocation response message, etc. This message includes, for example, at least one of the following information:

[0182] n Configuration response information of the target cell (for example, it can also be called the seventh information or other information names,

[0183] and the present invention does not impose any restrictions on the information names). This information contains the configuration information of the target cell generated by the third node. In one example, this information contains the information included in the RRC Reconfiguration message. When the third node agrees to use this target cell as the target cell of the first node, this information will be included in the first response message.

[0184] n Candidate cell configuration response information (for example, it can also be called the eighth information or other information names,

[0185] and the present invention does not impose any restrictions on the information names). This information contains the configuration information of the candidate cell generated by the third node (such as the response to the above candidate cell configuration request information, that is, the third node agrees to configure the candidate cell indicated in the above "candidate cell configuration request information" as the candidate cell of the first node). In one example, this information is a container containing candidate cell configuration information, such as LTM candidate. In another example, this information contains various configuration information related to the candidate cell, and these information are included in the first response message in an explicit manner (such as explicit information elements

[0186] (Information element)). In one embodiment, this information is the response to the above "first resource request information". The beneficial effect of this information is: to provide the configuration information of the candidate cell, which is convenient for pre-configuring the resources for the user equipment to switch, and reducing the interruption and delay of the handover. This information includes at least one of the following information (the descriptions of the various information included in this information can refer to the above "first configuration information of the candidate cell"):

[0187] n Configuration identification information;

[0188] n Identification information of the base station, such as the identification information of the gNB

[0189] n Identification information of the distributed unit, such as the identification information of the distributed unit of the base station, the identification information of the gNB-DU (gNB distributed unit)

[0190] n Identification information of the candidate cell;

[0191] n Configuration information of the synchronization signal;

[0192] n RRC configuration information;

[0193] n Indication information of the complete configuration;

[0194] n Configuration information of the synchronization;

[0195] n Configuration information of the beam;

[0196] n Resource configuration information of the reference signal;

[0197] n Configuration information related to the first reset;

[0198] n Configuration information related to the first TA measurement.

[0199] n Sharing indication information, which indicates that at least one of the information contained in the above "candidate cell configuration response information" is shared by multiple user equipments. Based on this information, the second node can allocate the resources indicated by the above "candidate cell configuration response information" (such as the resources indicated in the above "configuration information of the synchronization") to multiple users for use. The beneficial effect of this information is to reduce the signaling interaction between nodes, reduce the waste of resources by sharing resources, and improve the efficiency of resource use;

[0200] n Identification information of the user equipment

[0201] n Identification information of the cell, such as PCI, NR CGI, etc.; Optionally, the identification information of the cell includes the identification information of the candidate cell configured for the user equipment.

[0202] n Signal index information, which indicates the index of the allocated physical signal, such as the index of the preamble signal (Preamble Index)

[0203] n Carrier indication information, which indicates the carrier where the requested resource is located, such as a Normal UL carrier or a Supplement UL carriern Second synchronization signal index information, which indicates the index of the synchronization signal. In one example, the synchronization signal is an SSB (SS / PBCH block, PBCH:

[0204] Physical Broadcast Channel), and then the index information is the SSB Indexn Index information of the resource, which indicates the index information of the requested resource. In one example, the index information is the Physical Random Access Channel Mask Index information;

[0205] n Information about the usage time, which indicates the time when the resource requested by the second node is used. That is, within the time indicated by this information, the second node can use the resource; otherwise, it will not use the resource;

[0206] n Request rejection indication information, which indicates that the third node has rejected the request of the second node or indicates that the third node has no resources to allocate. This information can be explicit indication information or implicit indication information. In addition, this information can also include the configuration information of the rejected resources, and this configuration information can refer to the information indicated by the above "first configuration information of the candidate cell" or "candidate cell configuration response information". According to this information, the second node can know which requested resources have been rejected or cannot be allocated.

[0207] n Response information related to the configured candidate cell (for example, it can also be called the third information or other information names, and the present invention does not impose any restrictions on the name of the information), which indicates the information of the candidate cell that has been configured for the first node and accepted by the third node, or indicates the information of the candidate cell that has been configured for the first node and cannot be accepted by the third node. In one example, the accepted or unaccepted candidate cell is the candidate cell configured by the second node for the first node, such as the candidate cell configured by the source cell for the first node. This response message can be a response to the "candidate cell assistance information" in the first request message or a response to the "first configuration information of the candidate cell" in the first request message. The beneficial effect of this information is: to help the second node know the candidate cells accepted by the third node, so as to release or update the candidate cells configured for the first node and improve the resource utilization efficiency of the base station of the serving candidate cell. This information may contain the information of one or more candidate cells. For a candidate cell, this information includes, for example, one of the following information:

[0208] Identification information of n candidate cells (for example, it can also be called identification information of the second candidate cell or other information names, and the present invention does not impose any restrictions on the name of the information), such as PCI, NR CGI, etc.

[0209] n Configuration identification information (for example, it can also be called the second configuration identification information or other information names, and the present invention does not impose any restrictions on the name of the information), which identifies the configuration corresponding to the candidate cell, such as LTM configuration identification, LTM candidate identification.

[0210] n Second user identification information (for example, it can also be called the first user identification information or other information names, and the present invention does not impose any restrictions on the name of the information). In one example, this information indicates the identification information used when the first node accesses the base station of the cell, such as the identification information of the radio interface (C-RNTI), the identification information of the interface of the base station (such as XnAP UE ID, and further, this ID is the identification information of the first node on the side of the above-mentioned third node). When the third node performs signaling interaction with the base station where the candidate cell is located, the third node can include this identification information in the signaling to update the configuration of the candidate cell.

[0211] n Second configuration information of the candidate cell (for example, it can also be called the sixth information or other information names, and the present invention does not impose any restrictions on the name of the information), which contains the configuration of one or more candidate cells accepted by the third node. The information contained in this information can refer to the description in the above "first configuration information of the candidate cell".

[0212] n First configuration request information, which is used to request the second node to provide the configuration information of the cell identified by the above "identification information of the candidate cell" or "configuration identification information". After receiving this information, the second node will provide the information of the candidate cell to the third node in subsequent steps. In one example, the cell identified by the above "identification information of the candidate cell" is the cell accepted by the third node.

[0213] Step 1-3: Optionally, the second node sends a first confirmation message to the third node (for example, it can also be called the third message or other message names, and the present invention does not impose any restrictions on the message names). The function of this message is to provide the third node with information about the candidate cells configured for the first node. When the above first request message does not provide information about the candidate cells configured for the first node, this step can be used to provide the configuration information of the candidate cells. In one example, this first confirmation message is a response to the "response information related to the configured candidate cells" in the above first response message. An example of this message is SN (Sequence number) status transfer. This message includes at least one of the following information:

[0214] The second auxiliary information of the n cell (for example, it can also be called the tenth information, or other information names,

[0215] and the present invention does not impose any restrictions on the information names). The function of this information is to indicate the configuration information related to the base station of the cell serving the first node. In one example, this cell can be a candidate cell configured for the first node. In another example, this cell can be the target cell for configuring the first node. In another example, this cell can be the serving cell of the first node. After receiving this information, the third node will perform signaling interaction with the base station of the cell serving the first node based on this information to perform subsequent configuration (for example, when a user accesses the target cell served by the third node, the third node performs configuration update of the candidate cell with the base station of the candidate cell. See the signaling interaction process in steps 2-1 and 2-2 below). This information includes at least one of the following information:

[0216] The n cell configuration indication information. One possible function of this information is to indicate whether candidate cells are configured for the first node, and another possible function is to request the third node to accept the candidate cells configured for the first node. After receiving this information, the third node can decide whether to accept the candidate cells configured for the first node.

[0217] The n information related to the base station. The function of this information is to indicate the configuration information related to the base station of the candidate cell or target cell or serving cell. After receiving this information, the third node can perform signaling interaction with this base station based on this information to perform subsequent configuration (for example, when a user accesses the target cell or candidate cell served by the third node, the third node performs configuration update of the candidate cell with the base station of the candidate cell. See the signaling interaction process in steps 2-1 and 2-2 below).

[0218] This information includes at least one of the following information:

[0219] The identification information of the base station (such as the fifth node) where the u cell is located.

[0220] The identification information of the u-cell, such as PCI, NR CGI, etc.

[0221] The identification information of the u-third user. In one example, this information indicates the identification information used when the first node accesses the base station of the cell, such as the identification information of the air interface

[0222] (C-RNTI), the identification information of the interface of the base station (such as XnAP UE ID, and further, this ID is the identification information of the first node on the side of the above-mentioned fifth node). When the third node performs signaling interaction with the base station of the cell, the third node can include this identification information in the signaling, and then the base station of the cell can find the context of the first node according to this information, so as to perform the configuration update of the cell. In one example, this identification can be named contextID, or it can be named other names. n The third configuration information of the candidate cell (for example, it can also be called the ninth information, or other information names, and the present invention does not impose any restrictions on the name of the information). This information includes the configuration information of one or more candidate cells configured for the first node, and the specific information included in this information can refer to the "first configuration information of the candidate cell" in the above step 1-1.

[0223] Step 1-4: The second node sends a first user configuration message to the first node. The function of this message is to configure the target cell or candidate cell for the handover of the first node. This message includes at least one of the following information:

[0224] n The configuration information of the target cell, which includes the configuration information related to the target cell, such as the

[0225] configuration information of random access, the configuration information of the bearer, the configuration information of the cell group (CellGroupConfig). n The fifth configuration information of the candidate cell, and the specific information included in this information can refer to the "first configuration information of the candidate cell" in the above step 1-1.

[0226] The beneficial effect of the above process is: to help the third node obtain the candidate cell information configured for the first node, so as to determine the accepted candidate cell, configure the LTM cell change after the first node accesses the third node, and reduce the communication interruption of the first node during the movement process.

[0227] The first request message in the above process can be a handover request message, a configuration update request message, a resource request message, or other messages;

[0228] The first response message in the above process may be a Handover Request Acknowledge message, a Configuration update response message, a Resource response message, or other messages;

[0229] The first acknowledgment message in the above process may be a SN Status Transfer message, or other messages.

[0230] By the above method, it is possible to configure both layer 3 handover and LTM (L1 / L2 triggered mobility) handover simultaneously. That is, when the user equipment performs a handover based on layer 3 signaling, the network side can configure candidate cells for LTM for the user equipment. In this way, when the user equipment accesses the target cell, a cell change based on LTM can still be performed in the target cell, thereby reducing the communication interruption of the user equipment during the handover process.

[0231] By the above method, a resource request can be implemented, and the requested resources can be served by one or more users served by the first node. In a specific implementation, the above method can implement a request for resources for random access, which is used to obtain uplink timing advance information for accessing a cell served by a third node. After the first node receives the requested resources, it can allocate them for different users to use. When the first node includes a central unit and a distributed unit, the requested resources can also be used by users served by different distributed units within the first node. Specifically, the distributed unit of the first node can send a request message to the central unit of the first node, and this message is used to request the central unit of the first node to allocate resources for random access. Then, the distributed unit of the first node will allocate the requested random access resources to the user equipment. The specific description of this process can be referred to the subsequent description of the present invention.

[0232] The above process may have the following possible implementation manners, for example:

[0233] When the first request message is used to prepare the target cell for L3 handover, the possible implementation manners are as follows:

[0234] Implementation manner 1: Information on the configured candidate cells is sent through the first request message.

[0235] Step 1-1: The second node sends a first request message to the third node, and this message includes at least one of the following information:

[0236] n target cell configuration request information;

[0237] The first auxiliary information of the n cells

[0238] The first configuration information of the n candidate cells

[0239] Step 1-2: The third node sends a first response message to the second node, and the message includes at least one of the following information:

[0240] The configuration response information of the n target cells

[0241] The response information related to the configured candidate cells

[0242] Embodiment 2: The information of the configured candidate cells is sent through a first confirmation message, and the third node obtains the candidate cells configured for the first node through the "first configuration information of the candidate cells" included in the first request message

[0243] Step 1-1: The second node sends a first request message to the third node, and the message includes at least one of the following information:

[0244] The target cell configuration request information

[0245] The first configuration information of the candidate cells

[0246] Step 1-2: The third node sends a first response message to the second node, and the message includes at least one of the following information:

[0247] The configuration response information of the target cells

[0248] The response information related to the configured candidate cells

[0249] Step 1-3: The second node sends a first confirmation message to the third node, and the message includes at least one of the following information:

[0250] The second auxiliary information of the cells

[0251] The third configuration information of the candidate cells

[0252] Embodiment 3: The auxiliary information of the cells is sent through a first confirmation message, and the third node obtains the information of the configured candidate cells through the "first configuration information of the candidate cells" included in the first request message

[0253] Step 1-1: The second node sends a first request message to the third node, and the message includes at least one of the following information:

[0254] The target cell configuration request information

[0255] The first auxiliary information of the n cells, which does not contain information related to the base station of the candidate cell;

[0256] The first configuration information of the n candidate cells.

[0257] Step 1-2: The third node sends a first response message to the second node, which includes at least one of the following information:

[0258] The configuration response information of the n target cells;

[0259] The response information related to the configured candidate cells.

[0260] Step 1-3: The second node sends a first confirmation message to the third node, which includes at least one of the following information:

[0261] The second auxiliary information of the n cells.

[0262] When the first request message is used to prepare the candidate cells for LTM, the possible implementation methods are as follows:

[0263] Implementation method 4: The information of the configured candidate cells is sent through the first request message.

[0264] Step 1-1: The second node sends a first request message to the third node, which includes at least one of the following information:

[0265] The candidate cell configuration request information;

[0266] The first auxiliary information of the n cells;

[0267] The first configuration information of the n candidate cells.

[0268] Step 1-2: The third node sends a first response message to the second node, which includes at least one of the following information:

[0269] The configuration response information of the candidate cells;

[0270] The response information related to the configured candidate cells.

[0271] Implementation method 5: The information of the configured candidate cells is sent through the first confirmation message, and the third node obtains the candidate cells configured for the first node through the "first configuration information of the candidate cells" contained in the first request message.

[0272] Step 1-1: The second node sends a first request message to the third node, which includes at least one of the following information:

[0273] The candidate cell configuration request information;

[0274] The first configuration information of the n candidate cells.

[0275] Step 1-2: The third node sends a first response message to the second node, and the message includes at least one of the following information:

[0276] The configuration response information of the n candidate cells;

[0277] The response information related to the configured candidate cells.

[0278] Step 1-3: The second node sends a first confirmation message to the third node, and the message includes at least one of the following information:

[0279] The second auxiliary information of the cell;

[0280] The third configuration information of the n candidate cells.

[0281] Embodiment 6: The auxiliary information of the cell is sent through the first confirmation message, and the third node obtains the information of the configured candidate cells through the "first configuration information of the candidate cells" included in the first request message.

[0282] Step 1-1: The second node sends a first request message to the third node, and the message includes at least one of the following information:

[0283] The candidate cell configuration request information;

[0284] The first auxiliary information of the cell, and this information does not include the information related to the base station of the candidate cell;

[0285] The first configuration information of the n candidate cells.

[0286] Step 1-2: The third node sends a first response message to the second node, and the message includes at least one of the following information:

[0287] The configuration response information of the n candidate cells;

[0288] The response information related to the configured candidate cells.

[0289] Step 1-3: The second node sends a first confirmation message to the third node, and the message includes at least one of the following information:

[0290] The second auxiliary information of the cell.

[0291] When the first request message is used to prepare the target cell for L3 handover and the candidate cells for LTM, the possible embodiments are as follows:

[0292] Embodiment 7: The information of the configured candidate cells is sent through the first request message.

[0293] Step 1-1: The second node sends a first request message to the third node, which includes at least one of the following information:

[0294] n Target cell configuration request information;

[0295] n Candidate cell configuration request information;

[0296] n First auxiliary information of the cell;

[0297] n First configuration information of the candidate cell.

[0298] Step 1-2: The third node sends a first response message to the second node, which includes at least one of the following information:

[0299] n Target cell configuration response information;

[0300] n Configuration response information of the candidate cell;

[0301] n Response information related to the configured candidate cell.

[0302] Embodiment 8: The information of the configured candidate cell is sent through a first confirmation message, and the third node obtains the candidate cell configured for the first node through the "first configuration information of the candidate cell" included in the first request message.

[0303] Step 1-1: The second node sends a first request message to the third node, which includes at least one of the following information:

[0304] n Target cell configuration request information;

[0305] n Candidate cell configuration request information;

[0306] n First configuration information of the candidate cell.

[0307] Step 1-2: The third node sends a first response message to the second node, which includes at least one of the following information:

[0308] n Target cell configuration response information;

[0309] n Configuration response information of the candidate cell;

[0310] n Response information related to the configured candidate cell.

[0311] Step 1-3: The second node sends a first confirmation message to the third node, which includes at least one of the following information:

[0312] n Second auxiliary information of the cell;

[0313] n Third configuration information of the candidate cell.

[0314] Embodiment 9: The auxiliary information of the cell is sent through the first confirmation message, and the third node obtains the information of the configured candidate cell through the "first configuration information of the candidate cell" included in the first request message.

[0315] Step 1-1: The second node sends a first request message to the third node, and the message includes at least one of the following information:

[0316] n Target cell configuration request information;

[0317] n Candidate cell configuration request information;

[0318] n The first auxiliary information of the cell, and this information does not include information related to the base station of the candidate cell;

[0319] n The first configuration information of the candidate cell.

[0320] Step 1-2: The third node sends a first response message to the second node, and the message includes at least one of the following information:

[0321] n Target cell configuration response information;

[0322] n Candidate cell configuration response information;

[0323] n Response information related to the configured candidate cell.

[0324] Step 1-3: The second node sends a first confirmation message to the third node, and the message includes at least one of the following information:

[0325] n The second auxiliary information of the cell.

[0326] When the first request message is a request for resources, the possible embodiments are as follows:

[0327] Embodiment 10:

[0328] Step 1-1: The second node sends a first request message to the third node, and the message includes the above-mentioned "first resource request information";

[0329] Step 1-2: The third node sends a first response message to the second node, and the message includes the above-mentioned "candidate cell configuration response information";

[0330] Further, when the third node includes a central unit and a distributed unit, after the above step 1-1, it further includes:

[0331] Step 1-1a: The concentration unit of the third node sends a second request message to the distribution unit of the third node. This message is used to configure the cell of the first node or to request resource allocation from the distribution unit of the third node. The information contained in this message can be referred to the above "first request message".

[0332] Step 1-1b: The distribution unit of the third node sends a second response message to the concentration unit of the third node. This message is used to provide the configuration information of the cell configured for the first node or to provide the configuration information of the resources allocated by the third node. Further, this information may also include configuration update indication information, which indicates that the information contained in the above second response message is an update to the existing configuration. Based on the configuration information obtained in this step, the third node (or the concentration unit of the third node) can provide the above "first response message" to the second node.

[0333] When the second node includes a concentration unit and a distribution unit, the following steps may further be included after the above step 1-2:

[0334] Step 1-2-1: The concentration unit of the second node sends a first modification request message to the distribution unit of the second node. This message includes the configuration information of the candidate cell configured for the first node. The specific information contained in this information can be referred to the "first configuration information of the candidate cell" in the above step 1-1 or the "candidate cell configuration response information" in the above step 1-2. Further, this information may also include at least one of the following information:

[0335] Release request indication information, which indicates the released resources. An example of this resource is the resource of random access, and another example is the resource without random access

[0336] (RACH-less) resources, and another example is the resource of early (uplink) synchronization

[0337] synchronization). This information contains at least one of the following information:

[0338] Cell identification information, such as PCI, NR CGI, etc.; optionally, the cell identification information includes the identification information of the candidate cell configured for the user equipment.

[0339] Configuration information of the released resources. The information contained in this information can be referred to the above "configuration information of synchronization".

[0340] n The first resource request indication information, which indicates that the distribution unit of the second node needs to send a request message to the centralized unit of the second node to obtain resources. In one implementation, the distribution unit of the second node obtains the resource configuration information of the first node through the above steps 1-2-1

[0341] (In one example, the resources configured by this configuration information are random access resources, or non-random access resources, or early (uplink) synchronization resources), after which it cannot be directly used and needs to send a request to the centralized unit of the second node, and the latter will reallocate resources. After receiving this information, the distribution unit of the second node will send a request message to the centralized unit of the second node when it needs to use resources.

[0342] When the distribution unit of the second node needs to trigger the random access process (or early (uplink) synchronization process) of the first node, the following steps are further included:

[0343] Step 1-2-2: The distribution unit of the second node sends a third request message to the centralized unit of the second node. The function of this message is to request resources, and the requested resources are used for the first node to send physical signals. In one implementation, this step occurs after the above steps 1-2-1. Steps 1-2-1 provide a set of resources (such as the resources indicated by the above "first configuration information of the candidate cell" or "candidate cell configuration response information"), and step 1-2-2 is used to request the specific resources used by the first node. In another implementation, when the distribution unit of the second node needs to trigger the first node to send physical signals, it sends the above third request message to request resources. In one example, the above physical signal is a random access signal (such as a random access preamble signal), which is used to help the first node obtain the timing advance information of accessing the candidate cell. The beneficial effect of this message is that the distribution unit of the second node can request resources according to the needs of the first node, flexibly utilize the resources allocated by the third node (for example, these resources can be shared by multiple different user devices), and improve the resource utilization efficiency. The third request message includes at least one of the following information:

[0344] n Auxiliary information for requesting resources, which helps the centralized unit of the second node allocate resources. This information can be used to request one or more resources. One example of such resources is random access (RandomAccess) resources, another example is non-random access (RACH-less) resources, and another example is early (uplink) synchronization (Early(UL)synchronization) resources. The beneficial effect of this information is to help the centralized unit of the second node select appropriate resources for the first node to use and improve the resource utilization efficiency. For one requested resource, it includes at least one of the following information:

[0345] Identity information of the user equipment

[0346] Identity information of the cell, such as PCI, NR CGI, etc.; optionally, the identity information of the cell includes the identity information of the candidate cells configured for the user equipment.

[0347] Carrier indication information, which indicates the carrier where the requested resource is located, such as a normal uplink carrier (NormalUL carrier), a supplementary uplink carrier (Supplement UL carrier)

[0348] Synchronization signal index information, which indicates the index of the synchronization signal. In one example, if the synchronization signal is an SSB (SS / PBCH block, PBCH: Physical Broadcast Channel), then the index information is the SSB Index

[0349] Information on the first usage time, which indicates the time when the resource requested by the distribution unit of the second node is used. That is, within the time indicated by this information, the distribution unit of the second node can use this resource; otherwise, it will not use this resource;

[0350] Information on the requested resource, which indicates the resource requested by the distribution unit of the second node or the resource used by the distribution unit of the second node. After receiving this information, the central unit of the second node will decide whether the requested resource or the used resource can be used by the distribution unit of the second node. The beneficial effect of this information is that the distribution unit of the second node can select appropriate resources according to the state of the first node, help the central unit of the second node allocate appropriate resources, and improve the efficiency of resource utilization. This information includes at least one of the following information:

[0351] Identity information of the user equipment

[0352] Identity information of the cell, such as PCI, NR CGI, etc.; optionally, the identity information of the cell includes the identity information of the candidate cells configured for the user equipment.

[0353] Carrier indication information, which indicates the carrier where the requested resource is located, such as a normal uplink carrier (NormalUL carrier), a supplementary uplink carrier (Supplement UL carrier)

[0354] Signal index information, which indicates the index of the allocated physical signal, such as the index of the preamble signal (Preamble Index)

[0355] n Synchronization signal index information, which indicates the index of the synchronization signal. In one example, the synchronization signal is an SSB (SS / PBCH block, PBCH: Physical Broadcast Channel), then the index information is the SSB Index

[0356] n Index information of the resource, which indicates the index information of the requested resource. In one example, the index information is the Physical Random Access Channel Mask Index (PRACH Mask Index:

[0357] Physical Random Access Channel Mask Index) information;

[0358] n Information on the second usage time, which indicates the time when the resources requested by the distribution unit of the second node are used. That is, within the time indicated by this information, the distribution unit of the second node can use the resources, otherwise, it will not use the resources;

[0359] Furthermore, the above "auxiliary information for requesting resources" and "information on the requested resources" are methods for requesting different resources. The former requests resources from the central unit of the second node by providing auxiliary information, while the latter is that the distribution unit of the second node first determines the resources, then sends the determined resources to the central unit of the second node, and the central unit of the second node determines whether the requested resources are available.

[0360] Step 1-2-3: The central unit of the second node sends a third response message to the distribution unit of the second node. This message is used to allocate resources, so that the distribution unit of the second node can use the allocated resources to trigger the first node to send a physical signal, such as a random access signal (such as a random access preamble signal). Furthermore, the central unit of the second node may also have no resources to allocate, then the first modification response message can also be used to reject the resource request or indicate that the resource request fails. This message includes at least one of the following information:

[0361] n Identification information of the user equipment

[0362] n Identification information of the cell, such as PCI, NR CGI, etc.; optionally, the identification information of the cell includes the identification information of the candidate cells configured for the user equipment.

[0363] n The first resource information, which indicates the allocated resources. The resource configuration information contained in this information can refer to the information indicated by the above-mentioned "first configuration information of the candidate cell" or "candidate cell configuration response information". In addition, for the random access signal, this information may also include one or more allocated resources. For one resource, this information includes at least one of the following information:

[0364] n Signal index information, which indicates the index of the allocated physical signal, such as the index of the preamble signal (Preamble Index)

[0365] n Carrier indication information, which indicates the carrier where the requested resources are located, such as a normal uplink carrier (NormalUL carrier), a supplementary uplink carrier (Supplement UL carrier)

[0366] n Second synchronization signal index information, which indicates the index of the synchronization signal. In one example, this synchronization signal is an SSB (SS / PBCH block, PBCH:

[0367] Physical Broadcast Channel), then this index information is the SSB Index

[0368] n Index information of the resource, which indicates the index information of the requested resource. In one example, this index information is the physical random access channel mask index (PRACH Mask Index)

[0369] Information;

[0370] n Information on the third usage time, which indicates the time when the resources requested by the distribution unit of the second node are used. That is, within the time indicated by this information, the distribution unit of the second node can use these resources; otherwise, it will not use these resources;

[0371] n Request rejection indication information, which indicates that the central unit of the second node has rejected the request of the distribution unit of the second node, or indicates that the central unit of the second node has no resources available for allocation. This information can be explicit indication information or implicit indication information. In addition, this information can also include the configuration information of the rejected resources, and this configuration information can refer to the information indicated by the above-mentioned "first configuration information of the candidate cell" or "candidate cell configuration response information". Based on this information, the distribution unit of the second node can know which requested resources have been rejected or cannot be allocated.

[0372] Step 1-2-4: The distribution unit of the second node sends a trigger message to the first node. This trigger message is used to trigger the first node to send a physical signal, and one function of this physical signal is to help the first node obtain the timing advance information of the access candidate cell. This message includes at least one of the following information:

[0373] The identification information of the n cell, such as PCI, NR CGI, etc.; optionally, the cell identification information includes the identification information of the candidate cells configured for the user equipment.

[0374] The n carrier indication information, which indicates the carrier where the requested resource is located, such as a normal uplink carrier (NormalUL carrier), a supplementary uplink carrier (Supplement UL carrier)

[0375] The n synchronization signal index information, which indicates the index of the synchronization signal. In one example, if the synchronization signal is an SSB (SS / PBCH block (SS / PBCH block), PBCH: PhysicalBroadcast Channel), then this index information is the SSB Index

[0376] The n resource index information, which indicates the index information of the requested resource. In one example, this index information is the Physical Random Access Channel Mask Index (PRACH Mask Index:

[0377] Physical Random Access Channel Mask Index) information;

[0378] In the above process, the central unit of the second node can first obtain a set of resources from the third node, and then the distribution unit of the second node requests the required resources from the central unit of the second node when needed. This method is conducive to sharing the requested resource set by multiple users and improving the efficiency of resource utilization.

[0379] The following takes the physical signal sent by the first node as a random access signal (or a preamble signal of random access) as an example to introduce the implementation method of resource request.

[0380] Embodiment 11: The central unit of the second node obtains a set of resources and then allocates resources according to the request of the distribution unit of the second node. In this embodiment, when the central unit of the second node allocates resources, it selects appropriate resources from a resource set from the third node, which reduces the signaling interaction for requesting resources with the third node and also improves the efficiency of using these resources at the second node.

[0381] Step a: The second node or the concentration unit of the second node sends a first request message to the third node. The information contained in this message can be referred to the description in Step 1-1 above.

[0382] Step b: The third node sends a first response message to the second node or the concentration unit of the second node. This message contains the resource configuration information. The information contained in this message can be referred to the description in Step 1-2 above.

[0383] Step c: The distribution unit of the second node sends a third request message to the concentration unit of the second node. The description of this message can be referred to Step 1-2-2 above. In one example, the distribution unit of the second node requests the concentration unit of the second node to allocate resources by providing the above-mentioned "auxiliary information for requesting resources". In another example, the distribution unit of the second node requests to allocate the resources indicated by this information by the above-mentioned "information of the requested resources".

[0384] Step d: The concentration unit of the second node sends a third response message to the distribution unit of the second node. This message is used to indicate the allocated resources or reject the requested resources. The information contained in this message can be referred to Step 1-2-3 above.

[0385] Optionally, before Step c, it may further include:

[0386] Step c-0: The concentration unit of the second node sends a first modification request message to the distribution unit of the second node. This message is used to configure the set of resources obtained from the third node to the distribution unit of the second node. When the distribution unit of the second node obtains the allocated resources through the above-mentioned Step d, it can combine the information in this message to trigger the first node to send a physical signal, such as a random access signal.

[0387] Embodiment Twelve: The distribution unit of the second node requests resources through the concentration unit of the second node. In this embodiment, the distribution unit of the second node always requests resources through the concentration unit of the second node only when resources are needed, thus avoiding unnecessary resource waste (if according to Embodiment Eleven above, the third node needs to reserve a set of resources, which may lead to resource waste), and improving the efficiency of resource utilization.

[0388] Step a: The distribution unit of the second node sends a third request message to the concentration unit of the second node. The information contained in this message can be referred to Step 1-2-2 above.

[0389] Step b: The second node or the concentration unit of the second node sends a first request message to the third node. The information contained in this message can be referred to the description in Step 1-1 above.

[0390] Step c: The third node sends a first response message to the second node or the concentration unit of the second node. The information contained in this message can be referred to the description in the above Step 1-2.

[0391] Step d: The concentration unit of the second node sends a third response message to the distribution unit of the second node. This message is used to indicate the allocated resources or reject the requested resources. The information contained in this message can be referred to the above Step 1-2-3.

[0392] Optionally, before Step d, it may further include:

[0393] Step d-0: The concentration unit of the second node sends a first modification request message to the distribution unit of the second node. This message is used to configure the resources obtained from the third node to the distribution unit of the second node, and then the distribution unit of the second node triggers the first node to send a physical signal, such as a random access signal.

[0394] Please continue to refer to Figure 4 , Figure 4 which is a schematic diagram of the interaction between the second node and the third node according to an embodiment of the present disclosure.

[0395] After Step 1-2, the second node can learn the candidate cells that have been configured for the first node and accepted by the third node, and the candidate cells that have been configured for the first node but not accepted by the third node. Therefore, further, as Figure 4 shown, the above method may further include one or more of Step 1-2a to Step 1-2b:

[0396] Step 1-2a: The second node sends a first configuration update message (for example, it can also be called the sixth message or other message names, and the present invention does not limit the name of the message) to the fifth node, which is the base station serving the candidate cells configured for the first node. The function of this message is to inform the updated configuration information of the candidate cells. This message includes at least one of the following information: n Third resource configuration information, which is used to help the fifth node generate configuration information related to measuring other candidate cells in the candidate cell. In one example, this information is the configuration information of CSI (Channel State Information) resources, which can help the third node generate configuration information related to CSI measurement (such as measurement configuration information, measurement report configuration information). Further, this information can be the resource configuration information related to all candidate cells (such as LTM candidate cells) configured for the first node. Specifically, this information contains the identification information of the configuration of the candidate cell.

[0397] (configuration identification, or candidate identification), the SSB of the candidate cell

[0398] (SS / PBCH block) resource information, SSB index information (SSB Index). After receiving this information, the fifth node will generate configuration information for measuring these candidate cells according to the candidate cells configured for the first node.

[0399] Information on released candidate cells (for example, it can also be called the second release information or other information names, and the present invention does not impose any restrictions on the names of the information). This information indicates the candidate cells configured for the first node that need to be released, and this information includes at least one of the following information:

[0400] Identification information of the candidate cell, such as PCI, NR CGI.

[0401] Configuration identification information, which identifies the configuration corresponding to the candidate cell, such as LTM configuration identification (LTMconfiguration identification), LTM candidate identification (LTM candidateidentification).

[0402] The third auxiliary information of the cell (for example, it can also be called the eleventh information or other information names,

[0403] and the present invention does not impose any restrictions on the names of the information). The role of this information is to indicate the configuration information related to the base station (such as the third node) serving the first node. This base station can be the base station where the candidate cell or target cell or serving cell of the first node is located. After receiving this information, the fifth node will perform signaling interaction with the base station serving the first node according to this information to perform subsequent configuration of the candidate cell (such as interacting with the third node, see the signaling interaction process in steps 2-1 and 2-2 below).

[0404] This information includes at least one of the following information:

[0405] Identification information of the base station (such as the third node) where the cell is located. The base station where the cell is located can be the base station where the candidate cell of the first node is located, or the base station where the serving cell of the first node is located, or the base station where the target cell of the first node is located.

[0406] The identification information of the nth cell, such as PCI, NR CGI, etc. In one example, this information can be used to indicate the candidate cells accepted by the third node. In another example, the cell indicated by this information can be the serving cell or target cell where the first node is located, or it can also be the candidate cell of the first node.

[0407] The identification information of the fourth user (for example, it can also be called the third user identification information or other information names, and the present invention does not impose any restrictions on the name of the information). In one example, this information indicates the identification information used by the base station accessed by the first node, such as the identification information of the air interface (C-RNTI), the identification information of the interface of the base station (such as XnAP UE ID, and further, this ID is the identification information of the first node on the side of the above-mentioned third node). When the third node and the fifth node perform signaling interaction, the fifth node can include this identification information in the signaling to perform the configuration update of the candidate cell.

[0408] The fourth configuration information of the candidate cell (for example, it can also be called the twelfth information or other information names, and the present invention does not impose any restrictions on the name of the information). This information includes the configuration information of the candidate cell configured for the first node. For the specific information included in this information, reference can be made to the "first configuration information of the candidate cell" in step 1-1 above.

[0409] Step 1-2b: The fifth node sends a first configuration update response message to the second node. The function of this message is to update the configuration of the candidate cells served by the fifth node. This message can include the configuration information of the candidate cell. For the information included in this information, reference can be made to the "first configuration information of the candidate cell" in step 1-1 above.

[0410] Please continue to refer to Figure 5 , Figure 5 which is a schematic diagram of the interaction between the third node and the fifth node according to an embodiment of the present disclosure.

[0411] Through the above step 1-1 or step 1-3, the third node can learn the serving base station (such as the fifth node) of the candidate cell configured for the first node, and through the above step 1-2a, the fifth node can learn the base station (such as the third node) accessed by the first node. After that, the candidate configuration process of the candidate cell can be carried out between the third node and the fifth node, such as releasing the candidate cell, adding a new candidate cell, updating the configuration of the existing candidate cell, etc. Therefore, further, as Figure 5 shown, the above method may further include one or more of steps 2-1 to 2-2:

[0412] Step 2-1: The third node sends a second configuration update message to the fifth node (or the fifth node sends it to the third node) (for example, it can also be called the fourth message or other message names, and the present invention does not impose any restrictions on the message names). The message contains at least one of the following information: n user identification information (for example, it can also be called the second user identification information or other information names,

[0413] and the present invention does not impose any restrictions on the information names). This information is used to identify the first node on the third node and / or the fifth node, such as the above-mentioned first user identification information or third user identification information, and /

[0414] or the above-mentioned second user identification information or fourth user identification information.

[0415] n information on released candidate cells (for example, it can also be called the first release information or other information names, and the present invention does not impose any restrictions on the information names), such as cell identification, configuration identification, etc. n configuration information of updated candidate cells (for example, it can also be called the first update information or other information names, and the present invention does not impose any restrictions on the information names). For the specific content of this information, reference can be made to the "first configuration information of candidate cells" in the above step 1-1.

[0416] Step 2-2: The fifth node sends a second configuration update response message to the third node (or the third node sends it to the fifth node). The message contains at least one of the following information:

[0417] n user identification information, which is used to identify the first node on the third node and / or the fifth node, such as the above-mentioned first user identification information or third user identification information, and / or the identification information of the above-mentioned second user identification information or fourth user.

[0418] n configuration information of updated candidate cells. For the specific content of this information, reference can be made to the "first configuration information of candidate cells" in the above step 1-1.

[0419] The above first configuration update message or second configuration update message can be a Handover Request message or other messages;

[0420] The above first configuration update response message or second configuration update response message can be a Handover RequestAcknowledge message or other messages.

[0421] The beneficial effect of the above process is: to update the configuration of the candidate cells of the first node on the network side, so that after the serving cell of the first node changes, the configured candidate cells can still be maintained, thereby reducing subsequent handover data interruption.

[0422] Please continue to refer to Figure 6 , Figure 6 which is a schematic diagram of the interaction between a second node or a third node and a fourth node according to an embodiment of the present disclosure.

[0423] After the second node or the third node obtains the configuration information of the candidate cell, it will also provide the updated configuration information of the candidate cell to the fourth node. Therefore, further, as shown in Figure 6 , the above method may further include one or more of steps 3-1 to 3-2:

[0424] Step 3-1: The second node or the third node sends a third configuration update message to the fourth node (for example, it may also be referred to as the fifth message or other message names, and the present invention does not impose any restrictions on the message names). This message may include the updated configuration information of the candidate cell. For example, it may be referred to as the second update information or other message names (for specific content, please refer to the "first configuration information of the candidate cell" in step 1-1 above).

[0425] Step 3-2: The fourth node sends a third configuration update response message to the second node or the third node. This message provides the updated configuration information of the candidate cell at the fourth node (for specific content, please refer to the "first configuration information of the candidate cell" in step 1-1 above).

[0426] The above third configuration update message may be a UE context setup / modification request message, or other messages.

[0427] The above third configuration update response message may be a UE context setup / modification response message, or other messages.

[0428] The beneficial effect of the above process is to update the configuration information of the candidate cell at the distribution unit of the first node of the service, which facilitates the distribution unit to trigger the first node to perform handover and reduces the interruption of data transmission during handover.

[0429] In addition, it can be understood that the content included in each message in the above embodiments is only an example of the present disclosure. The content included in various similar or identical messages may be replaced with each other according to the situation, or named differently, or some items may be added or deleted. And for the sake of brevity, the meanings between similar content items may be mutually explained according to the context and will not be elaborated. The embodiments after modification and explanation still fall within the protection scope of the present invention.

[0430] Figure 7 is a block diagram showing the structure of a third node 400 according to an embodiment of the present disclosure.

[0431] Reference Figure 7 , the third node 400 includes a transceiver 401 and a controller 402. The transceiver 401 is configured to send signals to the outside and receive signals from the outside. The controller 402 is configured to execute the method performed by the third node as described above. The third node 400 can be implemented in the form of hardware, software, or a combination of hardware and software, so that it can execute the method performed by the third node described in the present disclosure.

[0432] Figure 8 is a block diagram showing the structure of the second node 500 according to an embodiment of the present disclosure.

[0433] Reference Figure 8 , the second node 500 includes a transceiver 501 and a controller 502. The transceiver 501 is configured to send signals to the outside and receive signals from the outside. The controller 502 is configured to execute the method performed by the second node. The second node 500 can be implemented in the form of hardware, software, or a combination of hardware and software, so that it can execute the method performed by the second node described in the present disclosure.

[0434] Figure 9 is a block diagram showing the structure of the fifth node 600 according to an embodiment of the present disclosure.

[0435] Reference Figure 9 , the fifth node 600 includes a transceiver 601 and a controller 602. The transceiver 601 is configured to send signals to the outside and receive signals from the outside. The controller 602 is configured to execute the method performed by the fifth node. The fifth node 600 can be implemented in the form of hardware, software, or a combination of hardware and software, so that it can execute the method performed by the fifth node described in the present disclosure.

[0436] Figure 10 is a block diagram showing the structure of the fourth node 700 according to an embodiment of the present disclosure.

[0437] Reference Figure 9 , the fourth node 700 includes a transceiver 701 and a controller 702. The transceiver 701 is configured to send signals to the outside and receive signals from the outside. The controller 702 is configured to execute the method performed by the fourth node. The fourth node 700 can be implemented in the form of hardware, software, or a combination of hardware and software, so that it can execute the method performed by the fifth node described in the present disclosure.

[0438] At least one embodiment of the present disclosure also provides a non-transitory computer-readable recording medium, on which a program for executing the above-described method when run by a computer is stored.

[0439] Various embodiments of the present disclosure can be implemented as computer-readable code specifically implemented on a computer-readable recording medium from a specific perspective. A computer-readable recording medium is any data storage device that can store data readable by a computer system. Examples of computer-readable recording media can include read-only memory (ROM), random access memory (RAM), compact disc read-only memory (CD-ROM), magnetic tapes, floppy disks, optical data storage devices, carrier waves (e.g., data transmission via the Internet), and the like. The computer-readable recording medium can be distributed by a computer system connected via a network, and thus the computer-readable code can be stored and executed in a distributed manner. Moreover, the functional programs, codes, and code segments for implementing various embodiments of the present disclosure can be easily interpreted by those skilled in the art of the field applying the embodiments of the present disclosure.

[0440] It will be understood that the embodiments of the present disclosure can be implemented in the form of hardware, software, or a combination of hardware and software. The software can be stored as program instructions or computer-readable code executable on a controller on a non-transitory computer-readable medium. Examples of non-transitory computer-readable recording media include magnetic storage media (e.g., ROM, floppy disks, hard disks, etc.) and optical recording media (e.g., CD-ROM, digital versatile disc (DVD), etc.). The non-transitory computer-readable recording medium can also be distributed on a network-coupled computer system such that the computer-readable code is stored and executed in a distributed manner. The medium can be read by a computer, stored in a memory, and executed by a controller. Various embodiments can be implemented by a computer or a portable terminal including a controller and a memory, and the memory can be an example of a non-transitory computer-readable recording medium suitable for storing a program having instructions for implementing the embodiments of the present disclosure. The present disclosure can be implemented by a program having code for specifically implementing the devices and methods described in the claims, the program being stored in a machine (or computer) readable storage medium. The program can be electronically carried on any medium, such as a communication signal transmitted via a wired or wireless connection, and the present disclosure suitably includes its equivalents.

[0441] The above description is only the specific implementation manners of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present disclosure can make various changes or substitutions, and these changes or substitutions should be covered within the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claims.

Claims

1. A method performed by a third node in a communication system, the method comprising: Receiving, from a second node, a first message, the first message including first information related to one or more candidate cells configured for a first node, and / or second information related to a base station serving the one or more candidate cells, and / or first resource request information for requesting resources, and Sending, to the second node, a second message, the second message including third information related to one or more candidate cells configured for the first node that are accepted or not accepted by the third node, Wherein, the first message is used to request to prepare a target cell or candidate cells for handover of the first node.

2. The method according to claim 1, wherein, The first message further includes at least one of the following: Fourth information for requesting to configure a target cell for handover of the first node; Fifth information for requesting to configure candidate cells for handover of the first node.

3. The method according to claim 1 or 2, wherein, The first resource request information includes at least one of the following: Resource request indication information, identification information of a base station, identification information of a distributed unit, identification information of a cell, number of served users information, carrier indication information, index of a preamble signal, synchronization signal index information, physical random access channel mask index; The fourth information includes at least one of the following: Identification information of a target cell; First resource configuration information for being generated by the third node with configuration information related to measuring candidate cells within the target cell, The fifth information includes at least one of the following: Information related to layer 1 / layer 2 triggered mobility LTM handover; First configuration identification information for identifying a configuration corresponding to a candidate cell; Identification information of a first candidate cell for identifying the candidate cell for handover of the first node; Second resource configuration information for being generated by the third node with configuration information related to measuring other candidate cells within the candidate cell for handover of the first node; Second resource request information for requesting resources of the third node.

4. The method according to claim 1, wherein, The third information includes at least one of the following: Identification information of a second candidate cell for identifying the candidate cell accepted or not accepted by the third node; Second configuration identification information for identifying a configuration corresponding to the candidate cell accepted or not accepted by the third node; First user identification information, information related to an identification used when the first node accesses a base station where a cell is located; Sixth information, including a configuration of a candidate cell accepted or not accepted by the third node; First configuration request information for requesting the second node to provide configuration information of a candidate cell identified by the identification information of the second candidate cell or the configuration identification information.

5. The method according to claim 1, wherein, The second message further includes at least one of the following: Seventh information related to a configuration of a target cell for handover of the first node; Eighth information related to a configuration of a candidate cell for handover of the first node.

6. The method according to claim 1, wherein The method further includes: Receiving, from the second node, a third message, the third message including ninth information related to a candidate cell accepted by the third node, and / or tenth information related to a base station serving the candidate cell accepted by the third node.

7. The method according to claim 1, wherein The method further includes: Send a fourth message to a fifth node serving the candidate cell or receive the fourth message from the fifth node, where the fourth message includes at least one of the following: Second user identification information, including information related to identifying a first node on a third node and / or a fifth node; First release information, including information related to one or more candidate cells configured for the first node that need to be released; First update information, including information related to one or more candidate cells with updated configurations for the first node.

8. The method according to claim 1 or 7, wherein, The method further includes: Send a fifth message to a fourth node, where the fifth message includes second update information, and the second update information includes information related to one or more candidate cells with updated configurations for the first node, where the fourth node is a distributed unit DU and the third node is a central unit CU.

9. The method according to any one of claims 1, 4, 6, 7, and 8, wherein, The first information, sixth information, eighth information or ninth information, first update information, or second update information further includes at least one of the following: Third configuration identification information for identifying the configuration corresponding to the candidate cell; Identification information of a third candidate cell for identifying a candidate cell configured for the first node; Configuration information for synchronization signals, including information related to the configuration of synchronization signals of the candidate cell; Radio resource control (RRC) configuration information; Thirteenth information, including information related to whether the RRC configuration information is a complete configuration; Configuration information for synchronization, configuration information for triggering the first node to obtain synchronization information of the candidate cell; Configuration information for beams, including information related to the beams used when the first node transmits signals; Resource configuration information of reference signals, including information related to the resources of reference signals of the candidate cell; Configuration information related to the first reset, including information associated with operations related to determining the reset required for the third node when the cell of the first node changes; Configuration information related to the first timing advance (TA) measurement; Shared indication information indicating that the information is shared by multiple user equipments; Identification information of the user equipment; Identification information of the cell; Index of the preamble signal; Carrier indication information indicating the carrier where the requested resource is located; Index of the synchronization signal; Physical random access channel mask index; Information on the time of use.

10. The method according to claim 9, wherein The configuration information for synchronization includes at least one of the following: Configuration information related to the random access channel required for early synchronization; Configuration information related to the random access channel without random access; Configuration information related to early uplink synchronization; Configuration information related to contention-free random access; Configuration information related to the random access channel.

11. A method performed by a second node in a communication system, the method including: Send a first message to a third node, the first message including first information related to one or more candidate cells configured for a first node, and / or second information related to a base station serving the one or more candidate cells, and / or first resource request information for requesting resources, and Receive a second message from a third node, where the second message includes third information related to one or more candidate cells configured for the first node that are accepted or not accepted by the third node. Wherein, the first message is used to request preparation of a target cell or candidate cells for handover of the first node.

12. The method according to claim 11, wherein, The method further includes: Sending a sixth message to a fifth node, where the sixth message includes at least one of the following: Third resource configuration information, which is used for the fifth node to generate configuration information related to measuring other candidate cells within a candidate cell; Second release information, information related to one or more candidate cells configured for the first node that need to be released; Eleventh information, configuration information related to the base station serving the first node; Twelfth information, information related to one or more candidate cells configured for the first node.

13. The method according to claim 12, wherein, The eleventh information includes at least one of the following: Identification information of the base station; Identification information of the cell; Third user identification information, information related to the identification used when the first node accesses the base station.

14. The method according to claim 11, wherein When the second node includes a central unit and a distributed unit, the method further includes: The central unit of the second node receives a third request message sent by the distributed unit of the second node for requesting resources for sending a random access preamble signal, and The central unit of the second node sends a third response message for resource allocation to the distributed unit of the second node; The third request message includes at least one of the following: identification information of the cell, carrier indication information, synchronization signal index information; and The third response message includes at least one of the following: index of the preamble signal, physical random access channel mask index.

15. A node device, the node device includes: A transceiver configured to transmit and receive signals with the outside; And A controller configured to control the transceiver to execute the method according to any one of claims 1-14.

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