Communication method, device, communication system, and storage medium

Abstract

A communication method, a device, a communication system, and a storage medium. The method comprises: a first node determining that a cell handover to a first cell is to be performed, and sending first information to a terminal, the first information being used for instructing the terminal to perform the cell handover to the first cell, the first node being a node associated with a serving cell of the terminal, and the serving cell and the first cell corresponding to different nodes. The first node, by means of sending the first information to the terminal, enables the terminal to reliably perform handover to the first cell when the first cell and the serving cell correspond to different nodes.

Description

Communication method, device, communication system and storage medium Technical Field

[0001] The present disclosure relates to the field of communication technologies, and in particular to communication methods, devices, communication systems, and storage media. Background Art

[0002] For the dynamic cell or cell group handover process, a network node can control a terminal device to perform cell handover among multiple candidate cells or cell groups. However, there is currently a lack of effective means for performing cell or cell group handover between nodes.

[0003] Summary of the Invention

[0004] The embodiments of the present disclosure provide a communication method, a device, a communication system, and a storage medium.

[0005] According to a first aspect of an embodiment of the present disclosure, a communication method is provided, the method comprising:

[0006] The first node determines to perform cell switching to a first cell and sends first information to a terminal, where the first information is used to instruct the terminal to perform cell switching to the first cell. The first node is a node associated with a serving cell of the terminal, and the serving cell and the first cell correspond to different nodes.

[0007] According to a second aspect of an embodiment of the present disclosure, a communication method is provided, the method comprising:

[0008] The second node sends second information to the first node, where the second information includes timing advance TA-related information of the first cell. The first node is the node associated with the service cell of the terminal, and the second node is the node associated with the first cell. The first cell and the service cell correspond to different nodes.

[0009] According to a third aspect of an embodiment of the present disclosure, a communication method is proposed, the method including:

[0010] A terminal receives first information sent by a first node, where the first node is a node associated with a serving cell of the terminal;

[0011] The terminal performs cell handover to a first cell according to the first information, where the first cell and the serving cell correspond to different nodes.

[0012] According to a fourth aspect of an embodiment of the present disclosure, a first node is provided, wherein the first node includes:

[0013] A transceiver module is used to determine whether to perform cell switching to a first cell and send first information to a terminal, where the first information is used to instruct the terminal to perform cell switching to the first cell, the first node is a node associated with a serving cell of the terminal, and the serving cell and the first cell correspond to different nodes.

[0014] According to a fifth aspect of an embodiment of the present disclosure, a second node is provided, the second node including:

[0015] A transceiver module is used for a second node to send second information to a first node, where the second information includes timing advance TA-related information of the first cell, the first node is a node associated with the service cell of the terminal, the second node is a node associated with the first cell, and the first cell and the service cell correspond to different nodes.

[0016] According to a sixth aspect of an embodiment of the present disclosure, a terminal is provided, comprising:

[0017] a transceiver module, configured to receive first information sent by a first node, where the first node is a node associated with a serving cell of the terminal;

[0018] The processing module is configured to perform a cell handover to a first cell according to the first information, where the first cell and the serving cell correspond to different nodes.

[0019] According to a seventh aspect of an embodiment of the present disclosure, a first node is provided, including:

[0020] one or more processors;

[0021] A memory coupled to the one or more processors, the memory comprising executable instructions, which, when executed by the one or more processors, causes the first node to execute the communication method according to the first aspect.

[0022] According to an eighth aspect of an embodiment of the present disclosure, a second node is provided, including:

[0023] one or more processors;

[0024] A memory coupled to the one or more processors, the memory comprising executable instructions, which, when executed by the one or more processors, causes the second node to execute the communication method according to the second aspect.

[0025] According to a ninth aspect of an embodiment of the present disclosure, a terminal is provided, including:

[0026] one or more processors;

[0027] A memory coupled to the one or more processors, the memory comprising executable instructions, which, when executed by the one or more processors, causes the terminal to execute the communication method described in the third aspect.

[0028] According to the tenth aspect of an embodiment of the present disclosure, an embodiment of the present disclosure proposes a communication system, comprising a first node, a second node and a terminal, wherein the first node is configured to implement the communication method described in the first aspect, the second node is configured to implement the communication method described in the second aspect, and the terminal is configured to implement the communication method described in the third aspect.

[0029] According to the eleventh aspect of the embodiment of the present disclosure, a storage medium is proposed, which stores instructions. When the instructions are executed on a communication device, the communication device executes the communication method described in the first aspect, the second aspect, or the third aspect.

[0030] According to the twelfth aspect of the embodiments of the present disclosure, a computer program product is proposed, comprising a computer program and / or instructions, which, when executed by a communication device, implement the communication method as described in the first aspect, the second aspect, or the third aspect.

[0031] In the above embodiment, the first node may send the first information to the terminal so that the terminal can reliably switch to the first cell when the nodes corresponding to the first cell and the serving cell are different. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following drawings required for describing the embodiments are introduced. The following drawings are merely some embodiments of the present disclosure and do not impose specific limitations on the protection scope of the present disclosure.

[0033] FIG1A is an exemplary schematic diagram of the architecture of a communication system provided according to an embodiment of the present disclosure.

[0034] FIG1B is an exemplary schematic diagram of the architecture of a communication system provided according to an embodiment of the present disclosure.

[0035] FIG1C is an exemplary schematic diagram of the architecture of a communication system provided according to an embodiment of the present disclosure.

[0036] FIG1D is an exemplary schematic diagram of a dual-link architecture provided according to an embodiment of the present disclosure.

[0037] FIG2 is an exemplary interaction diagram of a communication method provided according to an embodiment of the present disclosure.

[0038] FIG3A is a schematic diagram of an exemplary flow chart of a communication method provided according to an embodiment of the present disclosure.

[0039] FIG3B is a schematic diagram of an exemplary flow chart of a communication method provided according to an embodiment of the present disclosure.

[0040] FIG3C is a schematic diagram of an exemplary flow chart of a communication method provided according to an embodiment of the present disclosure.

[0041] FIG3D is a schematic diagram of an exemplary flow chart of a communication method provided according to an embodiment of the present disclosure.

[0042] FIG4A is a schematic diagram of an exemplary flow chart of a communication method provided according to an embodiment of the present disclosure.

[0043] FIG4B is a schematic diagram of an exemplary flow chart of a communication method provided according to an embodiment of the present disclosure.

[0044] FIG4C is a schematic diagram of an exemplary flow chart of a communication method provided according to an embodiment of the present disclosure.

[0045] FIG4D is a schematic diagram of an exemplary flow chart of a communication method provided according to an embodiment of the present disclosure.

[0046] FIG5A is a schematic diagram of an exemplary flow chart of a communication method provided according to an embodiment of the present disclosure.

[0047] FIG5B is a schematic diagram of an exemplary flow chart of a communication method provided according to an embodiment of the present disclosure.

[0048] FIG5C is a schematic diagram of an exemplary flow chart of a communication method provided according to an embodiment of the present disclosure.

[0049] FIG6 is a schematic diagram of an exemplary interaction of a communication method provided according to an embodiment of the present disclosure.

[0050] FIG7A is a schematic diagram of an exemplary flow chart of a communication method provided according to an embodiment of the present disclosure.

[0051] FIG7B is a schematic diagram of an exemplary flow chart of a communication method provided according to an embodiment of the present disclosure.

[0052] FIG7C is a schematic diagram of an exemplary interaction of a communication method provided according to an embodiment of the present disclosure.

[0053] FIG7D is an exemplary interaction diagram of a communication method provided according to an embodiment of the present disclosure.

[0054] FIG7E is an exemplary interaction diagram of a communication method provided according to an embodiment of the present disclosure.

[0055] FIG7F is an exemplary interaction diagram of a communication method provided according to an embodiment of the present disclosure.

[0056] FIG7G is an exemplary interaction diagram of a communication method provided according to an embodiment of the present disclosure.

[0057] FIG7H is an exemplary interaction diagram of a communication method provided according to an embodiment of the present disclosure.

[0058] FIG8A is a schematic diagram of an exemplary structure of a first node provided according to an embodiment of the present disclosure.

[0059] FIG8B is a schematic diagram of an exemplary structure of a second node provided according to an embodiment of the present disclosure.

[0060] FIG8C is a schematic diagram of an exemplary structure of a terminal provided according to an embodiment of the present disclosure.

[0061] FIG9A is a schematic diagram of an exemplary structure of a communication device provided according to an embodiment of the present disclosure.

[0062] FIG9B is a schematic diagram of an exemplary structure of a communication device provided according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0063] The embodiments of the present disclosure provide a communication method, a device, a communication system, and a storage medium.

[0064] In a first aspect, an embodiment of the present disclosure provides a communication method, the method comprising:

[0065] The first node determines to perform cell switching to a first cell and sends first information to a terminal, where the first information is used to instruct the terminal to perform cell switching to the first cell. The first node is a node associated with a serving cell of the terminal, and the serving cell and the first cell correspond to different nodes.

[0066] In the above embodiment, the first node may send the first information to the terminal so that the terminal can reliably switch to the first cell when the nodes corresponding to the first cell and the serving cell are different.

[0067] In conjunction with some embodiments of the first aspect, in some embodiments, the method includes:

[0068] The first node receives second information sent by the second node, the second information including timing advance (TA) related information of the first cell, the first information including the TA value of the first cell, the TA value of the first cell being determined based on the second information, and the second node being the node associated with the first cell.

[0069] In the above embodiment, the second node may send TA-related information to the first node, so that the first node can send the TA value of the first cell to the terminal through the first information, which can further ensure the reliability of the terminal performing cell switching.

[0070] In combination with some embodiments of the first aspect, in some embodiments, the first node is a source base station and the second node is a candidate base station; or, the first node is a master node (Master Node, MN) and the second node is a candidate secondary node (Secondary Node, SN); or, the first node is a serving SN and the second node is a candidate SN.

[0071] In combination with some embodiments of the first aspect, in some embodiments, the TA-related information of the first cell includes at least one of the following corresponding to the first cell: a first cell identifier; a TA value; a preamble code; a random access radio network temporary identifier (Random Access Radio Network Temporary Identity, RA-RNTI); and a second node identifier.

[0072] In the above embodiment, configuring the TA-related information to include one or more of the above can enable the terminal or the first node to more accurately know the TA value corresponding to the first cell, thereby improving the efficiency and reliability of the terminal in performing cell switching.

[0073] In combination with some embodiments of the first aspect, in some embodiments, the first node is a source base station and the second node is a candidate base station, or the first node is a MN and the second node is a candidate SN,

[0074] The second information is determined and sent by the second node according to third information, the third information is sent by the terminal, and the third information includes a random access RA preamble code.

[0075] In the above embodiment, when the first node is an MN or a base station, the second node may directly send the second information to the first node, so that the first node determines the TA-related information corresponding to each candidate cell based on the second information.

[0076] In conjunction with some embodiments of the first aspect, in some embodiments, the first node is a serving SN and the second node is a candidate SN, and the first node receives the second information sent by the second node, including:

[0077] The first node receives second information sent by the MN, where the second information is determined by the second node according to third information and sent to the MN. The third information is sent by the terminal, and the third information includes an RA preamble code.

[0078] In the above embodiment, when the first node is a serving SN, the second node may forward the second information to the first node through the MN, thereby ensuring that the first node can reliably receive the second information.

[0079] In combination with some embodiments of the first aspect, in some embodiments, the third information is sent by the terminal using a first random access channel (RACH) resource, and the first RACH resource is used for early synchronization between the first cell and the terminal.

[0080] In the above embodiment, the first RACH resource can be used for early synchronization, and the terminal can obtain the TA value of the first cell before performing cell switching, which can effectively improve the efficiency of cell switching.

[0081] In conjunction with some embodiments of the first aspect, in some embodiments, the method includes:

[0082] The first node sends fourth information to the second node, where the fourth information is used to instruct the second node to determine a first random access channel (RACH) resource, where the second node is associated with the first cell, and the first RACH resource is used for early synchronization between the first cell and the terminal;

[0083] The first node receives fifth information sent by the second node, where the fifth information is used to indicate the first RACH resource.

[0084] In the above embodiment, the second node may determine the first RACH resource corresponding to the first cell in response to the fourth information, thereby enabling the first cell and the terminal to be synchronized in advance based on the first RACH resource, thereby effectively improving the efficiency of cell switching.

[0085] In conjunction with some embodiments of the first aspect, in some embodiments, the method includes:

[0086] The first node sends eighth information to the terminal, where the eighth information is used to indicate the first RACH resource.

[0087] In the above embodiment, after receiving the determined first RACH resource of the second terminal, the first node can send the first RACH resource to the terminal through the eighth information, so that the terminal can synchronize with the first cell in advance based on the first RACH resource, thereby improving the efficiency of cell switching.

[0088] In conjunction with some embodiments of the first aspect, in some embodiments, the fourth information includes a first configuration list, where the first configuration list is used to indicate a second RACH resource that has been configured by the first node, where the second RACH resource is used for early synchronization between at least one second cell and the terminal, and the fourth information is used to instruct the second node to determine the first RACH resource based on the second RACH resource.

[0089] And / or, the method comprises:

[0090] The first node sends sixth information to the second node, where the sixth information includes the first configuration list, and the sixth information is used to instruct the second node to update the first RACH resource according to the second RACH resource.

[0091] In the above embodiment, the first configuration list may be carried in the fourth information or the sixth information, so that there is no conflict between the RACH resources corresponding to the first cell determined by the second node and the configured RACH resources, thereby ensuring the reliability of early synchronization.

[0092] In combination with some embodiments of the first aspect, in some embodiments, the first node sending sixth information to the second node includes: the first node determining that the first RACH resource conflicts with the second RACH resource, and sending the sixth information to the second node.

[0093] In the above embodiment, the first node may send the sixth information to the second node only when determining that the first RACH resource conflicts with an already configured RACH resource. This can effectively reduce resource overhead while avoiding RACH resource conflicts.

[0094] In combination with some embodiments of the first aspect, in some embodiments, the method includes: the first node receiving seventh information sent by the second node, where the seventh information is used to indicate the updated first RACH resource.

[0095] In combination with some embodiments of the first aspect, in some embodiments, the first configuration list includes at least one of the following: a node identifier of a third node, where the third node is a node associated with the second cell; a cell identifier of the second cell; a configuration identifier corresponding to the second cell; and a configuration of RACH resources corresponding to the configuration identifier.

[0096] In the above embodiment, configuring the first configuration list to include at least one of the above information can enable the second node to accurately determine the relevant information of the configured RACH resources based on the first configuration list, thereby avoiding conflict between the first RACH resource and the second RACH resource.

[0097] In a second aspect, an embodiment of the present disclosure provides a communication method, the method comprising:

[0098] The second node sends second information to the first node, where the second information includes timing advance TA-related information of the first cell. The first node is the node associated with the service cell of the terminal, and the second node is the node associated with the first cell. The first cell and the service cell correspond to different nodes.

[0099] In conjunction with some embodiments of the second aspect, in some embodiments, the first node is a source base station, and the second node is a candidate base station; or,

[0100] The first node is a primary node MN, and the second node is a candidate secondary node SN; or

[0101] The first node is a serving secondary node SN, and the second node is a candidate SN.

[0102] In combination with some embodiments of the second aspect, in some embodiments, the TA-related information of the first cell includes at least one of the following corresponding to the first cell: a first cell identifier; a TA value; a preamble code; an RA-RNTI; and a second node identifier.

[0103] In conjunction with some embodiments of the second aspect, in some embodiments, the first node is a source gNB and the second node is a candidate gNB, or the first node is an MN and the second node is a candidate SN,

[0104] The second node sending second information to the first node includes:

[0105] The second node receives third information sent by the terminal, where the third information includes a random access RA preamble;

[0106] The second node determines, based on the third information, and sends the second information to the first node.

[0107] In conjunction with some embodiments of the second aspect, in some embodiments, the first node is a serving SN and the second node is a candidate SN,

[0108] The second node sending second information to the first node includes:

[0109] The second node sends the second information to the first node through the MN, where the second information is determined by the second node according to third information, the third information is sent by the terminal, and the third information includes an RA preamble code.

[0110] In combination with some embodiments of the second aspect, in some embodiments, the third information is sent by the terminal using a first random access RACH resource, and the first RACH resource is used for early synchronization between the first cell and the terminal.

[0111] In conjunction with some embodiments of the second aspect, in some embodiments, the method includes:

[0112] The second node receives fourth information sent by the first node;

[0113] The second node determines a first RACH resource, where the first RACH resource is used for early synchronization between the first cell and the terminal;

[0114] The second node sends fifth information to the first node, where the fifth information is used to indicate the first RACH resource.

[0115] In conjunction with some embodiments of the second aspect, in some embodiments, the fourth information includes a first configuration list, where the first configuration list is used to indicate a second RACH resource that has been configured by the first node, where the second RACH resource is used for early synchronization between at least one second cell and the terminal, and the fourth information is used to instruct the second node to determine the first RACH resource based on the second RACH resource.

[0116] And / or, the second node determining the first RACH resource includes: the second node receiving sixth information sent by the first node, the sixth information including the first configuration list; and the third node updating the first RACH resource according to the second RACH resource.

[0117] In conjunction with some embodiments of the second aspect, in some embodiments, the method includes:

[0118] The second node sends seventh information to the first node, where the seventh information is used to indicate the updated first RACH resource.

[0119] In conjunction with some embodiments of the second aspect, in some embodiments, the first configuration list includes at least one of the following:

[0120] a node identifier of a third node, where the third node is the node associated with the second cell;

[0121] a cell identifier of the second cell;

[0122] a configuration identifier corresponding to the second cell;

[0123] The configuration identifier indicates the configuration of the RACH resource.

[0124] In a third aspect, an embodiment of the present disclosure provides a communication method, the method comprising:

[0125] A terminal receives first information sent by a first node, where the first node is a node associated with a serving cell of the terminal;

[0126] The terminal performs cell handover to a first cell according to the first information, where the first cell and the serving cell correspond to different nodes.

[0127] In conjunction with some embodiments of the third aspect, in some embodiments, the method includes:

[0128] The terminal performs cell switching to the first cell based on the first cell TA value in the first information, where the first cell TA value is determined by the first node based on second information, the second information is sent by the second node, and the second information includes TA-related information of the first cell. The second node is a node associated with the first cell.

[0129] In conjunction with some embodiments of the third aspect, in some embodiments, the first node is a source base station, and the second node is a candidate base station; or,

[0130] The first node is a primary node MN, and the second node is a candidate secondary node SN; or

[0131] The first node is a serving SN, and the second node is a candidate SN.

[0132] In combination with some embodiments of the third aspect, in some embodiments, the TA-related information of the first cell includes at least one of the following corresponding to the first cell: a first cell identifier; a TA value; a preamble code; an RA-RNTI; and a second node identifier.

[0133] In conjunction with some embodiments of the third aspect, in some embodiments, the method includes:

[0134] The terminal sends third information to the second node, where the third information is used by the second node to determine the second information, and the third information includes a random access RA preamble code.

[0135] In combination with some embodiments of the third aspect, in some embodiments, the third information is sent by the terminal using a first random access RACH resource, where the first RACH resource is used for early synchronization between the first cell and the terminal.

[0136] In conjunction with some embodiments of the third aspect, in some embodiments, the method includes:

[0137] The terminal receives eighth information sent by the first node, where the eighth information is used to indicate a first RACH resource, and the first RACH resource is used for early synchronization between the first cell and the terminal.

[0138] In a fourth aspect, an embodiment of the present disclosure provides a first node, wherein the first node includes:

[0139] A transceiver module is used to determine whether to perform cell switching to a first cell and send first information to a terminal, where the first information is used to instruct the terminal to perform cell switching to the first cell, the first node is a node associated with a serving cell of the terminal, and the serving cell and the first cell correspond to different nodes.

[0140] In a fifth aspect, an embodiment of the present disclosure provides a second node, where the second node includes:

[0141] A transceiver module is used for a second node to send second information to a first node, where the second information includes timing advance TA-related information of the first cell, the first node is a node associated with the service cell of the terminal, the second node is a node associated with the first cell, and the first cell and the service cell correspond to different nodes.

[0142] In a sixth aspect, an embodiment of the present disclosure provides a terminal, comprising:

[0143] a transceiver module, configured to receive first information sent by a first node, where the first node is a node associated with a serving cell of the terminal;

[0144] The processing module is configured to perform a cell handover to a first cell according to the first information, where the first cell and the serving cell correspond to different nodes.

[0145] In a seventh aspect, an embodiment of the present disclosure provides a first node, including:

[0146] one or more processors;

[0147] A memory coupled to the one or more processors, the memory comprising executable instructions, which, when executed by the one or more processors, causes the first node to execute the communication method according to the first aspect.

[0148] In an eighth aspect, an embodiment of the present disclosure provides a second node, including:

[0149] one or more processors;

[0150] A memory coupled to the one or more processors, the memory comprising executable instructions, which, when executed by the one or more processors, causes the second node to execute the communication method according to the second aspect.

[0151] In a ninth aspect, an embodiment of the present disclosure provides a terminal, including:

[0152] one or more processors;

[0153] A memory coupled to the one or more processors, the memory comprising executable instructions, which, when executed by the one or more processors, causes the terminal to execute the communication method described in the third aspect.

[0154] In the tenth aspect, an embodiment of the present disclosure proposes a communication system, comprising a first node, a second node and a terminal, wherein the first node is configured to implement the communication method described in the first aspect, the second node is configured to implement the communication method described in the second aspect, and the terminal is configured to implement the communication method described in the third aspect.

[0155] In the eleventh aspect, an embodiment of the present disclosure proposes a storage medium, which stores instructions. When the instructions are executed on a communication device, the communication device executes the communication method described in the first aspect, the second aspect, or the third aspect.

[0156] In a twelfth aspect, an embodiment of the present disclosure proposes a computer program, which, when executed on a computer, enables the computer to execute the method described in the optional implementation of the first and second aspects.

[0157] In a thirteenth aspect, an embodiment of the present disclosure provides a chip or a chip system, wherein the chip or chip system includes a processing circuit configured to execute the method described in the optional implementation of the first and second aspects above.

[0158] In the fourteenth aspect, an embodiment of the present disclosure provides a computer program product, including a computer program and / or instructions, which, when executed by a communication device, implement the communication method as described in the first aspect, the second aspect, or the third aspect.

[0159] It is understandable that the first node, the second node, the terminal, the communication system, the storage medium, the program product, the computer program, the chip, or the chip system are all used to perform the method proposed in the embodiment of the present disclosure. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects of the corresponding method and will not be repeated here.

[0160] The embodiments of the present disclosure provide a communication method, a first node, a second node, a terminal, a communication system, and a storage medium. In some embodiments, the terms "communication method" and "information processing method" and "data transmission method" and "cell switching method" are interchangeable; the terms "communication device" and "information processing device" and "data transmission device" and "cell switching device" are interchangeable; and the terms "communication system" and "information processing system" are interchangeable.

[0161] The embodiments of the present disclosure are not exhaustive and are merely illustrative of some embodiments, and are not intended to be a specific limitation on the scope of protection of the present disclosure. In the absence of contradiction, each step in a certain embodiment can be implemented as an independent embodiment, and the steps can be arbitrarily combined. For example, a solution after removing some steps in a certain embodiment can also be implemented as an independent embodiment, and the order of the steps in a certain embodiment can be arbitrarily exchanged. In addition, the optional implementation methods in a certain embodiment can be arbitrarily combined; in addition, the embodiments can be arbitrarily combined. For example, some or all steps of different embodiments can be arbitrarily combined, and a certain embodiment can be arbitrarily combined with the optional implementation methods of other embodiments.

[0162] In each embodiment of the present disclosure, unless otherwise specified or provided for by logic, the terms and / or descriptions between the embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form a new embodiment based on their inherent logical relationships.

[0163] The terms used in the embodiments of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure.

[0164] In the embodiments of the present disclosure, unless otherwise specified, elements expressed in the singular, such as "a", "an", "the", "above", "said", "the", "the", etc., may mean "one and only one", or "one or more", "at least one", etc. For example, when using articles such as "a", "an", "the" in English in translation, the noun following the article may be understood as a singular expression or a plural expression.

[0165] In the embodiments of the present disclosure, “plurality” refers to two or more.

[0166] In some embodiments, the terms "at least one," "one or more," "a plurality of," "multiple," etc. may be used interchangeably.

[0167] In some embodiments, descriptions such as "at least one of A and B," "A and / or B," "A in one case, B in another case," or "in response to one case A, in response to another case B" may include the following technical solutions depending on the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed); and in some embodiments, A and B (both A and B are executed). The above is also applicable when there are more branches such as A, B, and C.

[0168] In some embodiments, "A or B" and other descriptions may include the following technical solutions depending on the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed). The above is also applicable when there are more branches such as A, B, C, etc.

[0169] The prefixes such as "first" and "second" in the embodiments of the present disclosure are only used to distinguish different description objects and do not constitute any restriction on the position, order, priority, quantity or content of the description objects. For the statement of the description object, please refer to the description in the context of the claims or embodiments, and no unnecessary restriction should be constituted due to the use of prefixes. For example, if the description object is a "field", the ordinal number before the "field" in the "first field" and the "second field" does not limit the position or order between the "fields". "First" and "second" do not limit whether the "fields" they modify are in the same message, nor do they limit the order of the "first field" and the "second field". For another example, if the description object is a "level", the ordinal number before the "level" in the "first level" and the "second level" does not limit the priority between the "levels". For another example, the number of description objects is not limited by the ordinal number and can be one or more. Taking "first device" as an example, the number of "devices" can be one or more. In addition, the objects modified by different prefixes can be the same or different. For example, if the description object is "device", then the "first device" and the "second device" can be the same device or different devices, and their types can be the same or different; for another example, if the description object is "information", then the "first information" and the "second information" can be the same information or different information, and their contents can be the same or different.

[0170] In some embodiments, “including A,” “comprising A,” “used to indicate A,” and “carrying A” can be interpreted as directly carrying A or indirectly indicating A.

[0171] In some embodiments, terms such as "time / frequency" and "time / frequency domain" refer to the time domain and / or the frequency domain.

[0172] In some embodiments, terms such as "in response to...", "in response to determining...", "in the case of...", "at the time of...", "when...", "if...", "if...", etc. can be used interchangeably.

[0173] In some embodiments, terms such as "greater than", "greater than or equal to", "not less than", "more than", "more than or equal to", "not less than", "higher than", "higher than or equal to", "not less than", and "above" can be replaced with each other, and terms such as "less than", "less than or equal to", "not greater than", "less than", "less than or equal to", "not more than", "lower than", "lower than or equal to", "not higher than", and "below" can be replaced with each other.

[0174] In some embodiments, devices, etc. can be interpreted as physical or virtual, and their names are not limited to the names recorded in the embodiments. Terms such as "device", "equipment", "device", "circuit", "network element", "node", "function", "unit", "section", "system", "network", "chip", "chip system", "entity", and "subject" can be used interchangeably.

[0175] In some embodiments, "network" can be interpreted as devices included in the network (eg, access network equipment, core network equipment, etc.).

[0176] In some embodiments, the terms "access network device (AN device)", "radio access network device (RAN device)", "base station (BS)", "radio base station" "fixed station", "node", "access point", "transmission point (TP)", "reception point (RP)", "transmission / reception point (TRP)" "panel", "antenna panel", "antenna array", "cell", "macro cell", "small cell", "femto cell", "pico cell", "sector", "cell group", "serving cell", "carrier", "component carrier", "bandwidth part (BWP)" and the like may be used interchangeably.

[0177] In some embodiments, the terms "terminal", "terminal device", "user equipment (UE)", "user terminal", "mobile station (MS)", "mobile terminal (MT)", subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, etc. can be used interchangeably.

[0178] In some embodiments, the access network device, the core network device, or the network device can be replaced by a terminal. For example, the various embodiments of the present disclosure can also be applied to a structure in which the communication between the access network device, the core network device, or the network device and the terminal is replaced by communication between multiple terminals (for example, device-to-device (D2D), vehicle-to-everything (V2X), etc.). In this case, it is also possible to set the structure in which the terminal has all or part of the functions of the access network device. In addition, terms such as "uplink" and "downlink" can also be replaced by terms corresponding to communication between terminals (for example, "side"). For example, uplink channels, downlink channels, etc. can be replaced by side channels, and uplinks, downlinks, etc. can be replaced by side links.

[0179] In some embodiments, the terminal may be replaced by an access network device, a core network device, or a network device. In this case, the access network device, the core network device, or the network device may have a structure that has all or part of the functions of the terminal.

[0180] In some embodiments, obtaining data, information, etc. may comply with the laws and regulations of the country where the data is obtained.

[0181] In some embodiments, data, information, etc. may be obtained with the user's consent.

[0182] In addition, each element, each row, or each column in the table of the embodiment of the present disclosure can be implemented as an independent embodiment, and the combination of any elements, any rows, and any columns can also be implemented as an independent embodiment.

[0183] FIG1A is a schematic diagram illustrating the architecture of a communication system according to an embodiment of the present disclosure. As shown in FIG1A , a communication system 100 includes a terminal 101 and a first node 102. Optionally, the first node 102 may be an access network device. Optionally, the terminal may access a core network or a core network device through the first node 103.

[0184] In some embodiments, the terminal 101 includes, for example, a mobile phone, a wearable device, an Internet of Things device, a car with communication function, a smart car, a tablet computer, a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal device in industrial control, a wireless terminal device in self-driving, a wireless terminal device in remote medical surgery, a wireless terminal device in a smart grid, a wireless terminal device in transportation safety, a wireless terminal device in a smart city, and at least one of a wireless terminal device in a smart home, but is not limited thereto.

[0185] In some embodiments, the access network device is, for example, a node or device that accesses a terminal to a wireless network. The access network device may include an evolved NodeB (eNB), a next generation evolved NodeB (ng-eNB), a next generation NodeB (gNB), a node B (NB), a home node B (HNB), a home evolved nodeB (HeNB), a wireless backhaul device, a radio network controller (RNC), a base station controller (BSC), a base transceiver station (BTS), a base band unit (BBU), a mobile switching center, a base station in a 6G communication system, an open base station (Open RAN), a cloud base station (Cloud RAN), a base station in other communication systems, and at least one of an access node in a Wi-Fi system, but is not limited thereto.

[0186] In some embodiments, the technical solution of the present disclosure can be applied to the Open RAN architecture. In this case, the interfaces between or within the access network devices involved in the embodiments of the present disclosure can be transformed into internal interfaces of the Open RAN, and the processes and information interactions between these internal interfaces can be implemented through software or programs.

[0187] In some embodiments, the access network device can be composed of a centralized unit (CU) and a distributed unit (DU), where the CU can also be called a control unit. The CU-DU structure can be used to split the protocol layer of the access network device, with the functions of some protocol layers centrally controlled by the CU, and the functions of the remaining part or all of the protocol layers distributed in the DU, which is centrally controlled by the CU, but is not limited to this.

[0188] In some embodiments, the core network device may be a single device including a first network element, a second network element, etc., or may be a plurality of devices or a group of devices, each including all or part of the first network element, the second network element, etc. The network element may be virtual or physical. The core network may include, for example, at least one of an evolved packet core (EPC), a 5G core network (5GCN), and a next generation core (NGC).

[0189] Figure 1B is a schematic diagram illustrating the architecture of a communication system according to an embodiment of the present disclosure. As shown in Figure 1B , communication system 100 includes a terminal 101 and a first node 102, and may also include a second node 103. Optionally, second node 103 may also be an access network device. Optionally, the terminal may access a core network or a core network device through first node 103. Optionally, first node 102 and second node 103 may correspond to different centralized units.

[0190] In some embodiments, Multi-Radio Dual Connectivity (MR-DC) is a generalized Intra-E-UTRA dual connectivity, in which the terminal 101 can utilize radio resources provided by two different schedulers. These schedulers are located on two different Next Generation Radio Access Network (NG-RAN) nodes, such as the first node 102 and the second node 103, connected by a non-ideal backhaul, one providing New Radio (NR) access and the other providing Evolved Universal Terrestrial Radio Access (E-UTRA) or NR access. One acts as a mobile network (MN) and the other as a network node (SN). The MN and the SN are connected via a network interface, where at least the MN is connected to the core network.

[0191] Figure 1C is a schematic diagram of the NR-DC architecture according to an embodiment of the present disclosure. As shown in Figure 1C, NG-RAN supports NR-NR DC (NR-DC), in which a UE connects to a gNB acting as a mobile node and another gNB acting as a network node. The primary gNB connects to the 5GC via the NG interface, and the two gNBs are connected via the Xn interface. The secondary gNB can also connect to the 5GC via the NG-U interface. NR-DC can also be used for UEs to access a single gNB, acting as both a mobile node and a network node, with both a mobile group and a network node configured.

[0192] In some embodiments, under dual connectivity, a UE, such as terminal 101, can access two cell groups, namely a master cell group (MCG) and a secondary cell group (SCG). Figure 1D is a schematic diagram of a dual-link architecture shown in an embodiment of the present disclosure. As shown in Figure 1D, under MCG, there may be many cells, one of which is used to initiate initial access, and this cell is called a primary cell (PCell). The PCell under MCG and the secondary cell (SCell) under MCG are combined through carrier aggregation (CA). The primary cell in MCG is PCell, and the secondary cell is SCell; the primary and secondary cells in SCG are PSCell, and the secondary cell is SCell. Because a lot of signaling is only sent on PCell and PSCell.

[0193] It can be understood that the communication system described in the embodiment of the present disclosure is for the purpose of more clearly illustrating the technical solution of the embodiment of the present disclosure, and does not constitute a limitation on the technical solution proposed in the embodiment of the present disclosure. Ordinary technicians in this field can know that with the evolution of the system architecture and the emergence of new business scenarios, the technical solution proposed in the embodiment of the present disclosure is also applicable to similar technical problems.

[0194] The following embodiments of the present disclosure can be applied to the communication system 100 shown in Figures 1A, 1B, 1C, and 1D, or part of the subject, but are not limited thereto. The subjects shown in Figures 1A, 1B, 1C, and 1D are examples. The communication system may include all or part of the subjects in Figures 1A, 1B, 1C, and 1D, or may include other subjects other than those in Figures 1A, 1B, 1C, and 1D. The number and form of each subject are arbitrary, and each subject can be physical or virtual. The connection relationship between the subjects is an example, and the subjects can be connected or disconnected. The connection can be in any manner, and can be direct or indirect, and can be wired or wireless.

[0195] The embodiments of the present disclosure can be applied to Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 5G new radio (NR), future radio access (FRA), new radio access technology (RAT), new radio (NR), new radio access (NX), future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), Public Land Mobile Network (PLMN) networks, Device-to-Device (D2D) systems, Machine-to-Machine (M2M) systems, Internet of Things (IoT) systems, Vehicle-to-Everything (V2X), systems utilizing other communication methods, and next-generation systems based on and extending these methods. Furthermore, multiple systems may be combined (for example, a combination of LTE or LTE-A with 5G).

[0196] In some embodiments, Layer 1 / Layer 2 Triggered Mobility (LTM) refers to a PCell / PSCell cell switch triggered by the network via a MAC CE based on L1 / L2 measurements, which may be accompanied by a MCG / SCG change. LTM can be used to reduce mobility latency.

[0197] In some embodiments, the gNB receives an L1 measurement report from the UE. Based on the L1 measurement report, the gNB changes the UE's serving cell via a cell switch command issued by the gNB via a MAC CE. Optionally, the cell switch command indicates an LTM candidate cell configuration that the gNB previously provided to the UE via RRC signaling. The UE accesses the target cell indicated in the cell change command according to the received cell switch command.

[0198] In some embodiments, the mobility operation in the dual connectivity scenario may include an MCG mobility operation and / or an SCG mobility operation.

[0199] The MCG mobility operation may include at least one of the following: PCell change, SCell change, SCell addition, SCell deletion, and MCG change. PCell change may also be referred to as handover.

[0200] The SCG mobility operation may include at least one of the following: PSCell change, PSCell addition, PSCell deletion, SCell change, SCell addition, SCell deletion, SCG change, SCG addition, SCG deletion.

[0201] In some embodiments, the MCG mobility operation and the SCG mobility operation may be performed independently or in parallel. For example, a PSCell change may be triggered alone, or a PSCell addition may be triggered alone, or a PCell change and a PSCell change may be triggered simultaneously, or a PCell change and a PSCell addition may be triggered simultaneously, or a PCell change, an SCell change in the MCG, a PSCell change, and an SCell change in the SCG may be triggered simultaneously, or other individual or combined scenarios.

[0202] Optionally, terms such as "mobility operation", "mobility", "cell change (Cell Switch)", "cell group change", "serving cell change (Cell Switch), handover" etc. can be used interchangeably.

[0203] In some embodiments, the above mobility operation in the dual connectivity scenario may be triggered by LTM or other mobility methods, which is not limited in the present disclosure.

[0204] In some embodiments of the present disclosure, the communication system may support mobility operations. For example, the access network device may configure one or more mobility configuration identifiers corresponding to the mobility operation for the terminal device, and the mobility configuration identifier is used to instruct the terminal device to execute mobility configuration information corresponding to the mobility operation.

[0205] A mobility configuration identifier may correspond to a candidate cell. For example, a mobility configuration identifier may correspond to a cell identifier of a candidate cell, which may be a physical cell identifier (PCI) and / or a global cell identifier (CGI). The candidate cell may be a cell measured by a terminal device. Based on the measurement results of the candidate cell, the terminal device may determine a target cell from one or more candidate cells and trigger a mobility operation (such as cell change or cell addition) corresponding to the target cell.

[0206] A mobility configuration identifier may also correspond to mobility configuration information of a candidate cell.

[0207] In some embodiments, the access network device may configure configuration information for the terminal device for mobility operations, where the configuration information may include at least one of the following:

[0208] Mobility reference configuration information;

[0209] Mobility configuration information corresponding to one or more candidate cells;

[0210] Channel State Information (CSI) resource configuration, for example, LTM CSI resource configuration information.

[0211] Optionally, the configuration information can be configured through LTM-Config.

[0212] In some embodiments, the mobility reference configuration information can be configured by the access network device to the terminal device. The mobility reference configuration information can be common to all cells in the same cell group (for example, an MCG or an SCG), and the cell group can be a candidate cell group.

[0213] In some embodiments, the mobility configuration information corresponding to a candidate cell may include:

[0214] Mobility configuration identifier;

[0215] cell identifier of the candidate cell;

[0216] The candidate configuration information may be represented by RRC reconfiguration (RRCReconfiguration).

[0217] In one implementation, the candidate configuration information may be a configuration in an RRC reconfiguration message associated with the candidate cell.

[0218] For example, the candidate configuration may be incremental configuration information relative to the mobility reference configuration information. In this way, each cell only needs to configure the incremental configuration corresponding to the cell, thereby reducing the amount of information required to be configured in each cell and reducing the consumption of radio resources by air interface signaling.

[0219] For another example, the candidate configuration information may be complete configuration information including mobility reference configuration information and incremental configuration information.

[0220] In some embodiments, the mobility configuration information corresponding to the candidate cells may be configured for the terminal device by the access network device through RRC signaling, and the configuration may include at least one of addition, modification, and release.

[0221] Through the above configuration information, the terminal device can determine the cell identifier of the candidate cell corresponding to the mobility configuration identifier, and can also determine the corresponding mobility configuration identifier through the cell identifier of the candidate cell.

[0222] In some embodiments, the candidate cell may be a candidate primary cell PCell, a candidate primary secondary cell PSCell, or a candidate secondary cell SCell.

[0223] In some embodiments, the candidate cell group may be a candidate primary cell group MCG or a candidate secondary cell group SCG.

[0224] In some embodiments, the above-mentioned mobility operation may be an LTM-based mobility operation, the above-mentioned configuration information for the mobility operation may be the configuration information for LTM, the above-mentioned mobility configuration identifier may be the LTM configuration identifier, and the above-mentioned mobility configuration information corresponding to the candidate cell may be the LTM configuration information corresponding to the candidate cell. The LTM configuration information may be configured through the LTM-Candidate information element. For example, the candidate cell configuration may be added, modified or deleted through ltm-CandidateToReleaseList and ltm-CandidateToAddModList.

[0225] In some embodiments, the terminal device may measure the candidate cell based on the above-mentioned mobility configuration information to obtain a measurement result of the candidate cell. For example, based on the LTM mobility operation, the terminal device performs L1 measurement on the candidate cell and may obtain at least one of the following measurement results: physical layer reference signal receiving power (Layer 1 Reference Signal Receiving Power, L1-RSRP), physical layer signal to interference plus noise ratio (Layer 1 Signal to Interference plus Noise Ratio, L1-SINR), and physical layer reference signal receiving quality (Layer 1 Reference Signal Receiving Quality, L1-RSRQ).

[0226] In some embodiments, the terminal device may send a measurement result to the access network device, and the access network device may send a first indication to the terminal device based on the measurement result. The first indication may be used to instruct the terminal device to perform a mobility operation.

[0227] Optionally, the name of the first indication is not limited, for example, it can be "mobility operation indication", "mobility operation command", "cell change command (Cell Switch Command)", "cell change command", "cell add command", "cell deletion command", "cell change indication", "cell change indication", "cell add indication", "cell deletion indication", etc.

[0228] In one implementation, the first indication may indicate a mobility configuration identifier that an access network device provides to the terminal device in advance through RRC signaling. The terminal device determines the mobility configuration identifier based on the received first indication and accesses the candidate cell corresponding to the mobility configuration identifier.

[0229] In another implementation, the first indication may indicate a cell identifier of a candidate cell, and the terminal device may access the candidate cell corresponding to the cell identifier.

[0230] In some embodiments, the access network device may send the above-mentioned first indication through L1 signaling or L2 signaling, wherein the L1 signaling may include downlink control information (DCI) or other L1 signaling, and the L2 signaling may include a medium access control control element (MAC CE) or other L2 signaling.

[0231] In some embodiments, the communication system may also support subsequent LTM (Subsequent LTM), which refers to the subsequent LTM cell switching process between candidate cells without the need for RRC reconfiguration by the access network device. That is to say, after performing a mobility operation (such as cell switching), the terminal device will not autonomously delete the LTM configuration. The LTM configuration can continue to be used even without RRC reconfiguration and update, and is used to trigger subsequent LTM (Subsequent LTM).

[0232] In some embodiments, scenarios of LTM-based mobility operations may include at least one of the following:

[0233] Intra-DU mobility operations involve changing, adding, or deleting cells within the same DU, i.e., the target cell and the source cell belong to the same DU.

[0234] Inter-DU mobility operations involve changing, adding, or deleting cells between different DUs, i.e., the target cell and the source cell belong to different DUs;

[0235] Intra CU mobility operations involve changing, adding, or deleting cells within the same CU, i.e., the target cell and the source cell belong to the same CU;

[0236] Inter-CU mobility operations involve changing, adding, or deleting cells between different CUs, i.e., the target cell and the source cell belong to different CUs.

[0237] In some embodiments, the above-mentioned CUs can also be referred to as inter-node, inter-gNB or inter-access network devices, and the target cell and the source cell belong to different access network devices (nodes, base stations).

[0238] In some embodiments, the above intra-CU mobility operation scenario may include inter-DU mobility operation and / or intra-DU mobility operation within a CU.

[0239] In some embodiments, in the SCG PSCell cell change triggered based on inter-CU LTM, an access network device serving as a MN may participate, and the MN may be used to coordinate the configuration between candidate PSCells of different CUs.

[0240] In some embodiments, based on the correspondence between different cells and access network devices, the mobility operation in the dual connectivity scenario may include at least one of the following:

[0241] MCG mobility operations within the master node (intra-MN); MCG mobility operations between master nodes (inter-MN); SCG mobility operations within the secondary node (intra-SN); SCG mobility operations between secondary nodes (inter-SN); MCG mobility operations and SCG mobility operations between nodes (inter-Node).

[0242] In some embodiments, the mobility operation in the dual connectivity scenario (eg, LTM-based mobility operation) may be triggered by at least one of the MN, the SN, or the terminal device.

[0243] In some embodiments, for SCG mobility operations within a secondary node (intra-SN), mobility configuration information (eg, LTM configuration information) corresponding to the SCG mobility operations may be sent directly by the SN to the terminal device, or transparently transmitted by the SN to the terminal device via the MN.

[0244] Optionally, the SCG mobility operation within the secondary node (intra-SN) based on LTM can be performed without the participation of the MN. After the terminal device performs the cell change, the RRC reconfiguration complete message can be sent to the SN. For example, the RRC reconfiguration complete message can be sent directly to the SN via SRB3 or through MN transparent transmission.

[0245] In other embodiments, for scenarios of inter-SN SCG mobility operations, or inter-Node MCG mobility operations and SCG mobility operations, in order to implement inter-node PScell ​​changes or additions, the participation of the MN is required, and the MN needs to exchange information with the source SN and the candidate SN. The LTM configuration in this scenario can be configured to the terminal device by the MN. After the terminal device performs the cell change, the terminal device can send an MN RRC reconfiguration complete message carrying the SN RRC reconfiguration complete message to the MN, and then the MN can forward the SN RRC reconfiguration complete message therein to the target SN.

[0246] Optionally, the MN RRC reconfiguration complete message may be referred to as a first message or a first RRC reconfiguration complete message, and the SN RRC reconfiguration complete message may be referred to as a second message or a second RRC reconfiguration complete message.

[0247] In some embodiments, a UE can send an RA preamble to a candidate cell. Based on the received preamble, the candidate cell obtains the TA corresponding to the UE in the candidate cell. This TA value is included in the Cell Switch Command sent by the serving cell to the UE. Upon receiving the Cell Switch Command carrying the TA, the UE can trigger RACH-less LTM.

[0248] In some embodiments, the random access procedure for LTM candidate cells used for early TA acquisition can use contention-free random access (CFRA) triggered by a PDCCH command. For example, the terminal sends MSG1 to the cell but does not monitor the cell's response. Optionally, to support terminal power boosting, the terminal can retransmit MSG1 based on network instructions.

[0249] In some embodiments, intra-CU mobility operations can support early TA acquisition. That is, during the execution of LTM, the terminal performs early TA acquisition on the candidate cell according to the network's requirements before receiving the cell handover command. This process can be completed by triggering CFRA with the PDCCH command of the source cell. The terminal can then send a preamble to the designated candidate cell. To minimize data interruption caused by the source cell sending CFRA to the candidate cell, the terminal will not receive a random access response from the network when acquiring the TA value. The TA value of the candidate cell can be carried in the cell handover command.

[0250] In some embodiments, for intra-CU gNB LTM, the serving cell and target cell are located on the same gNB, so no node-to-node interaction is required to transmit TA information. However, when the serving cell and candidate cell are located on different gNBs, ensuring reliable cell handover is a pressing issue.

[0251] FIG2 is an interactive diagram of a communication method according to an embodiment of the present disclosure. As shown in FIG2 , the present disclosure embodiment relates to a communication method, and the method includes:

[0252] Step S2101: The first node sends fourth information to the second node.

[0253] In some embodiments, the first node is a node associated with a serving cell of the terminal. The terminal can access the serving cell through the first node. Optionally, the first node can also be referred to as a serving node.

[0254] In some embodiments, the second node is a node associated with the first cell. Upon receiving a relevant indication from the first node or determining that a corresponding event has been triggered, the terminal may access the first cell through the second node, thereby using the first cell as the terminal's serving cell. Alternatively, the second node may also be referred to as a candidate node, and the first cell may also be referred to as a candidate cell.

[0255] In some embodiments, the number of candidate nodes and candidate cells may be greater than or equal to 2. Optionally, the second node may be a node associated with one or more candidate cells, and the first cell may include one or more candidate cells associated with the second node.

[0256] For example, the second node may be any one of the candidate nodes, and the first cell may include one or more candidate cells corresponding to the second node. Alternatively, the first cell may be any one of the candidate cells, and the second node may be a node corresponding to the first cell.

[0257] In some embodiments, the first node is a source base station and the second node is a candidate base station; or, the first node is a master node MN and the second node is a candidate secondary node SN; or, the first node is a serving SN and the second node is a candidate SN.

[0258] In some embodiments, the first cell and the serving cell correspond to different nodes. Optionally, the first cell and the serving cell correspond to different nodes (e.g., base stations) or centralized units (CUs). That is, the terminal can perform cell handover between nodes, between base stations, or between CUs.

[0259] In some embodiments, when the first node is a source base station or a mobile node, the corresponding cell handover may be referred to as an MCG LTM. Alternatively, when the first node is a mobile node or a serving mobile node, the corresponding cell handover may be referred to as an SCG LTM. Alternatively, when the first node is a mobile node, the corresponding cell handover may be referred to as an MN initiated SCG LTM. Alternatively, when the first node is a serving mobile node, the corresponding cell handover may be referred to as an SN initiated SCG LTM.

[0260] In some embodiments, the MCG LTM is used to trigger the mobility of the MCG and / or PCell.

[0261] In some embodiments, the SCG LTM is used to trigger the mobility of the SCG and / or PSCell.

[0262] In some embodiments, the first node sends fourth information to each of the candidate nodes.

[0263] In some embodiments, the fourth information is used to instruct the second node to determine the first RACH resource. Optionally, the first RACH resource is used for early synchronization between the first cell and the terminal.

[0264] In some embodiments, the second node is a node associated with one or more candidate cells, and the fourth information is used to instruct the second node to determine a RACH resource corresponding to each candidate cell associated with the second node.

[0265] In some embodiments, the fourth information includes information related to requesting early synchronization. Optionally, the fourth information is used by the second node to determine whether to prepare corresponding first RACH resources for early synchronization for the first cell. For example, when the fourth information indicates "True" or a specific value, or is configured, it may indicate that the first node requests the second node to prepare corresponding RACH resources for early synchronization for the first cell.

[0266] In some embodiments, the fourth information may include a first configuration list. Optionally, the first configuration list indicates a second RACH resource that the first node has configured. Optionally, the fourth information instructs the second node to determine the first RACH resource based on the second RACH resource. Optionally, the second RACH resource is used for early synchronization between at least one second cell and the terminal.

[0267] In some embodiments, the node associated with the second cell may be referred to as a third node. Optionally, the third node is a node associated with the second cell. That is, the terminal may access the second cell through the third node.

[0268] In some embodiments, the first cell and the second cell may both be referred to as candidate cells, and the third node and the second node may both be referred to as candidate nodes. It is understood that the second cell may be one or more cells among the candidate cells that are different from the first cell, and the third node may be one or more nodes among the candidate nodes that are different from the second node.

[0269] In some embodiments, before the first node sends the fourth information to the second node, the first node may receive fifth information sent by the third node and determine a first configuration list, wherein the fifth information sent by the third node may be used to indicate the second RACH resource.

[0270] The first node may send fourth information to the second node after determining the configuration of the RACH resource corresponding to the second cell, for example, after receiving the fifth information sent by the third node, and include the first configuration list in the fourth information sent to the second node. In this way, when the second node determines the first RACH resource, a conflict between the first RACH resource and the second RACH resource can be avoided.

[0271] In some embodiments, the first configuration list includes at least one of the following: a node identifier of the third node; a cell identifier of the second cell; a configuration identifier corresponding to the second cell; and a configuration of a RACH resource corresponding to the configuration identifier.

[0272] For example, the second node can determine, based on the first configuration list, one or more second cells corresponding to one or more third nodes, and determine the configuration identifiers corresponding to the one or more second cells, thereby determining the RACH resource configuration corresponding to each second cell, such as the starting and ending time-frequency domain positions of the RACH resources. Furthermore, when determining the first RACH resource, the second node can avoid the RACH resource corresponding to the second cell already configured by the first node, thereby preventing different candidate nodes from generating the same RACH resource for Early Sync for their corresponding different cells.

[0273] That is, the first node may include, in the fourth information sent to any candidate node, a configuration list of Early Sync resources configured for candidate cells corresponding to other candidate nodes excluding the candidate node, so that when the candidate node determines the corresponding RACH resource, it can avoid conflict with the already configured resources.

[0274] In some embodiments, the fourth information may be an Xn message, or an inter-node Radio Resource Control (RRC) message, or carried by an Xn message, or carried by an inter-node RRC message.

[0275] In some embodiments, the second information may be a "Handover Request message" or a "SN Addition Request message" or any other Xn message for requesting LTM. The embodiment of the present disclosure does not limit the name of the fourth message.

[0276] In some embodiments, the second node receives the fourth information. Optionally, the second node performs step S2102 in response to the fourth information. Optionally, after receiving the fourth information, the second node determines whether to perform step S2102 based on the fourth information.

[0277] Step S2102: The second node sends fifth information to the first node.

[0278] In some embodiments, the fifth information is used to indicate the first RACH resource. Optionally, the fifth information is used to indicate the first RACH resource determined by the second node.

[0279] In some embodiments, the fifth information may be determined by the second node based on the first configuration list in the fourth information. For example, the second node determines the first RACH resource and the corresponding fifth information based on the first configuration list, where the first RACH resource does not conflict with the second RACH resource, for example, the time-frequency domain position corresponding to the first RACH resource does not overlap with the time-frequency domain position corresponding to the second RACH resource.

[0280] In some embodiments, the fifth information may be a confirmation message of the fourth information. Optionally, the fifth information may be an Xn message, or an inter-node Radio Resource Control (RRC) message, or carried by an Xn message, or carried by an inter-node RRC message. Optionally, the fifth information may also be an "EarlyUL-SyncConfig Information Element (IE)", or carried by an "EarlyUL-SyncConfig IE".

[0281] In some embodiments, the fifth information may be a "Handover Request Acknowledge message" or a "SN Addition Request Acknowledge message" or any other confirmation message used to request LTM, or it may be a "Handover Preparation" message or a "Handover Command". The embodiment of the present disclosure does not limit the name of the fifth information.

[0282] In some embodiments, the first node receives fifth information from the second node. Optionally, the first node updates the configured second RACH resource based on the received fifth information, for example, adding the first RACH resource indicated by the second node to the second RACH resource. Optionally, the first node updates the first configuration list based on the received fifth information.

[0283] In some embodiments, in response to receiving the fifth information, the first node executes step S2103 or step S2105. Alternatively, the first node determines whether to execute step S2103 based on the received fifth information.

[0284] For example, after receiving the fifth information, if the first node determines that the first RACH resource conflicts with the second RACH resource, step S2103 and subsequent steps may be executed; if the first RACH resource conflicts with the second RACH resource, step S2105 and subsequent steps may be executed.

[0285] In some embodiments, step S2103 and step S2104 are optional steps, and the first node executes step S2105 in response to the fifth information.

[0286] Step S2103: The first node sends sixth information to the second node.

[0287] In some embodiments, the sixth information includes a first configuration list, where the first configuration list is used to indicate the second RACH resource that has been configured by the first node.

[0288] In some embodiments, the sixth information is used to instruct the second node to update the first RACH resource according to the second RACH resource.

[0289] In some embodiments, the first node sends sixth information to the second node in response to fifth information sent by the second node. Alternatively, the first node sends sixth information to the second node based on the fifth information. Alternatively, the first node determines whether to send the sixth information to the second node based on the fifth information sent by the second node.

[0290] In some embodiments, the first node determines that the first RACH resource indicated by the fifth information sent by the second node conflicts with the second RACH resource, and sends sixth information to the second node.

[0291] That is, after receiving the fifth message from the candidate node, the first node may send the candidate node a sixth message containing a configuration list of Early Sync resources configured for candidate cells corresponding to other candidate nodes. The candidate node may then update the RACH resources generated for the corresponding candidate cell based on the sixth message to avoid conflicts. If the first node detects a RACH resource conflict, the first node may send the sixth message to the candidate node with the resource conflict.

[0292] In some embodiments, the sixth information and the fourth information may be the same or different. For example, the sixth information and the fourth information may have the same message name. The sixth information may be, for example, a "Handover Request message," a "SN Addition Request message," or any other Xn message used to request LTM. The present disclosure does not limit the name of the message.

[0293] In some implementations, the second node receives the sixth information sent by the first node. Optionally, the second node updates the first RACH based on the sixth information. Optionally, the second node updates the first RACH based on the sixth information and executes step S2104.

[0294] Step S2104: The second node sends seventh information to the first node.

[0295] In some embodiments, the seventh information is used to indicate the updated first RACH resource.

[0296] In some embodiments, the first node receives the seventh information. Optionally, the first node updates the second RACH resource based on the seventh information, for example, by adding the updated first RACH resource to the second RACH resource. Optionally, the first node updates the first configuration list based on the seventh information.

[0297] In some embodiments, the first node executes step S2105 in response to the seventh information. Optionally, the first node executes step S2105 after receiving the seventh information.

[0298] In some embodiments, the seventh information and the fifth information may be the same or different. For example, the seventh information and the fifth information may have the same message name. The seventh information may be, for example, a "Handover Request Acknowledge message" or a "SN Addition Request Acknowledge message," or any other confirmation message for requesting LTM, or a "Handover Preparation" message or a "Handover Command." The present disclosure does not limit the name of the seventh information.

[0299] Step S2105: The first node sends eighth information to the terminal.

[0300] In some embodiments, the eighth information is used to indicate the first RACH resource. Optionally, the eighth information is used to indicate the updated first RACH resource.

[0301] For example, after the first node receives the fifth information or the seventh information sent by the second node, it can send the first RACH resource related information indicated by the fifth information or the seventh information to the terminal, so that the terminal can at least know the RACH resource corresponding to the first cell, such as the starting time-frequency domain position and the ending time-frequency domain position of the terminal for early synchronization with the first cell.

[0302] In some embodiments, the eighth information includes a first configuration list. Optionally, the eighth information is used to indicate a second RACH resource, and the second RACH resource includes the first RACH resource. Optionally, the first RACH resource may be an updated first RACH resource.

[0303] That is, after receiving the fifth information or the seventh information, the first node can determine the first RACH resource indicated by the fifth information or the seventh information as the configured RACH resource, and use the eighth information to enable the terminal to know the configuration of the RACH resources corresponding to each candidate cell.

[0304] In some embodiments, the eighth information may include configurations of RACH resources associated with the candidate cells. Optionally, the eighth information may include at least one of the following: a node identifier of at least one candidate node, such as the node identifier of the second node; a cell identifier of at least one candidate cell, such as the cell identifier of the first cell; a configuration identifier corresponding to each candidate cell, such as the configuration identifier corresponding to the first RACH resource; and a RACH resource corresponding to each configuration identifier.

[0305] In some embodiments, the eighth information may be referred to as "candidate cell configuration information", "RACH resource configuration", "RRC configuration", etc., and the embodiments of the present disclosure do not limit the names thereof.

[0306] In some embodiments, one or more of the above steps S2101 to S2105 may be a process of negotiating Early RACH resources.

[0307] In some embodiments, Early RACH resource negotiation may include at least one of the following: Early RACH resource negotiation in an MCG LTM scenario; Early RACH resource negotiation in an MN-initiated SCG LTM scenario; and Early RACH resource negotiation in an SN-initiated SCG LTM scenario. The Early RACH resource negotiation process in each scenario can be described in detail with reference to the embodiments shown in FIG. 7C to FIG. 7D , and is not described in detail here.

[0308] Step S2106: The terminal sends third information to the second node.

[0309] In some embodiments, the third information is used for early synchronization of the terminal with the first cell, for example, to facilitate the second node to determine the second information, and the second information may include, for example, TA-related information of the first cell. Optionally, the TA-related information includes at least a TA value corresponding to the terminal in the first cell.

[0310] In some embodiments, the third information includes an RA preamble. Optionally, the third information is used for the terminal to synchronize with the first cell in advance. Optionally, the third information is used to request the second node to determine TA-related information of the first cell. Optionally, the RA preamble is used by the second node to determine TA-related information of the first cell.

[0311] In some embodiments, the second node is a node associated with one or more candidate cells, the first cell may include one or more candidate cells associated with the second node, and the third information is used to request the second node to determine TA-related information of the one or more candidate cells associated with the second node. Optionally, the RA preamble is used by the second node to determine TA-related information of the one or more candidate cells associated with the second node.

[0312] In some embodiments, the terminal initiates synchronization to the candidate node associated with the candidate cell, such as early synchronization, and the candidate node obtains TA-related information corresponding to the corresponding candidate cell based on the received RA preamble code, such as the TA value corresponding to the candidate cell.

[0313] In some embodiments, the terminal sends an RA preamble to a candidate node associated with the candidate cell, and the candidate node obtains TA-related information corresponding to the corresponding candidate cell, such as a TA value corresponding to the candidate cell, based on the received RA preamble.

[0314] In some embodiments, the TA-related information may include at least one of the following: a TA value of the first cell; a preamble; an RA-RNTI; and an identifier of the second node. Optionally, the TA value of the first cell may include TA values ​​corresponding to one or more candidate cells associated with the second node.

[0315] It can be understood that the TA-related information of the candidate cell can be the TA-related information between the candidate cell and the terminal, and the TA-related information can be used for more reliable communication between the terminal and the candidate cell. For example, the terminal can send data or signaling to the second node corresponding to the first cell based on the TA-related information of the first cell, or the second node in the first cell can send data or signaling to the terminal based on the TA-related information of the first cell.

[0316] In some embodiments, the first node is a source base station and the second node is a candidate base station, or the first node is an MN and the second node is a candidate SN. After the second node receives the third information, it can determine the TA-related information of the first cell and the corresponding second information based on the third information.

[0317] In some embodiments, the first node is a serving SN and the second node is a candidate SN. After receiving the third information, the second node can determine the TA-related information of the first cell and the corresponding second information based on the third information.

[0318] In some embodiments, the second node receives the third information sent by the terminal. Optionally, the second node determines TA-related information of the first cell based on the RA preamble. Optionally, the second node determines the second information based on the third information and executes step S2107. Optionally, the second node determines the second information based on the third information and sends the second information to the first node via the mobile node.

[0319] In some embodiments, the third information may be, for example, an "RA preamble," an "early TA acquisition (acqusition) message," etc., and the embodiments of the present disclosure do not limit the names thereof.

[0320] In some embodiments, the third information is transmitted using the first RACH resource. Optionally, the terminal uses the first RACH resource to send the third information to the second node. The first RACH resource may be determined based on one or more steps from step S2101 to step S2104, or by other means, which is not limited in this embodiment of the present disclosure.

[0321] In some embodiments, early synchronization may include early TA synchronization, and steps S2105 and S2106 described above may be early TA synchronization processes. That is, the terminal may obtain the TA value of the candidate cell in advance before performing a cell handover, thereby enabling the cell handover to be completed more quickly and reliably during the cell handover.

[0322] Step S2107: The second node sends second information to the first node.

[0323] In some embodiments, the second information is used to indicate TA-related information of the first cell, such as a TA value of the first cell. Optionally, the second information includes TA-related information of the first cell.

[0324] In some embodiments, the TA-related information of the first cell includes at least one of the following corresponding to the first cell: a first cell identifier; a TA value; a preamble; an RA-RNTI; and a second node identifier.

[0325] In some embodiments, the second information may be determined by the second node based on the third information. Optionally, the TA-related information of the first cell in the second information is determined based on information related to early synchronization. Optionally, the TA-related information may be determined based on information related to early synchronization in the third information, such as an RA preamble.

[0326] In some implementations, for MCG LTM or MN initiated SCG LTM, the second node may send the second information directly to the first node.

[0327] In some embodiments, the first node is a source base station and the second node is a candidate base station, or the first node is a mobile node and the second node is a candidate network node. The second information is determined and sent by the second node based on third information, and the third information includes a random access (RA) preamble. The third information may be sent by the terminal based on step S2106.

[0328] In some embodiments, for SN initiated SCG LTM, the second node may send the second information to the first node through the MN.

[0329] In some embodiments, the first node is a serving SN and the second node is a candidate SN, the second node sends second information to the MN, and the MN forwards the second information to the first node. Optionally, the first node receives the second information sent by the MN, where the second information is determined by the second node based on third information and sent to the MN.

[0330] In some embodiments, the second information may be an Xn message, such as a "TA information transfer message", or other messages. The embodiment of the present disclosure does not limit the name of the second information.

[0331] In some embodiments, for MCG LTM, the second information may further include at least one of the following: an Xn message type; a source base station identifier; a candidate base station identifier, such as a node identifier of the second node; or a terminal identifier. Optionally, the terminal identifier may include at least one of the following: an XnAP identifier of the terminal on the source base station or an XnAP identifier of the UE on the candidate base station.

[0332] For example, for MCG LTM, TA related information can be expressed as the following Table 1:

[0333] Table 1

[0334] Among them, Message Type can be used to indicate the Xn message type of the second information, the TA Information List can include multiple TA Information Item IEs corresponding to candidate cells associated with the second node, the Candidate Cell ID in the TA Information Item IE can be used to indicate the cell identifier of the candidate cell, the TA Value can be used to indicate the TA value corresponding to the candidate cell, the Preamble Index is used to indicate the preamble code corresponding to the candidate cell, and the Target NG-RAN node ID is used to indicate the node identifier of the candidate base station corresponding to the candidate cell.

[0335] In some embodiments, for a MN initiated SCG LTM or a SN initiated SCG LTM, the second information, in addition to TA-related information, may also include at least one of the following: an Xn message type; an MN identifier and / or a serving SN identifier, such as a node identifier of the second node; a candidate SN identifier; or a terminal identifier. Optionally, the terminal identifier may include, for example, an XnAP identifier of the terminal on the MN or an XnAP identifier of the terminal on the SN.

[0336] For example, for MN initiated SCG LTM or SN initiated SCG LTM, the TA-related information of the first cell can be represented as shown in the following Table 2:

[0337] Table 2

[0338] Among them, Message Type can be used to indicate the Xn message type of the second information, TA Information List can include TA Information Item IE corresponding to multiple candidate cells, Candidate Cell ID in TA Information Item IE can be used to indicate the cell identifier of the candidate cell, TA Value can be used to indicate the TA value corresponding to the candidate cell, Preamble Index is used to indicate the preamble code corresponding to the candidate cell, and Target S-NG-RAN node ID is used to indicate the node identifier of the candidate SN corresponding to the candidate cell.

[0339] In some embodiments, the first node receives the second information sent by the second node. Alternatively, the first node receives the second information sent by the second node via the MN. Alternatively, the first node determines the first information based on the second information and executes step S2108.

[0340] Step S2108: The first node sends first information to the terminal.

[0341] In some embodiments, the first node determines to perform a cell handover to the first cell and sends first information to the terminal.

[0342] In some embodiments, the first information includes a TA value of the first cell, and the TA value of the first cell may be determined according to the second information.

[0343] In some embodiments, the first node may receive a measurement report sent by the terminal and determine whether to trigger a cell handover based on the measurement report. Alternatively, the first node may determine whether to trigger a RACH-less LTM based on the measurement report.

[0344] In some embodiments, the measurement report may be a layer 1 L1 measurement report or a layer 2 L2 measurement report. The cell handover process triggered based on the L1 measurement report or the L2 measurement report may be referred to as L1 / L2 Triggered Mobility (LTM). Optionally, the above steps S2101 and S2104 may be a process for configuring LTM candidate cells.

[0345] In some embodiments, the first node determines whether to instruct the terminal to perform cell handover to the first cell based on the measurement report. Alternatively, the first node determines a first cell to be handed over among candidate cells based on the measurement report sent by the terminal, and sends first information to the terminal.

[0346] It can be understood that the first node can receive the second information sent by multiple candidate nodes and determine the TA values ​​of multiple candidate cells. When the first node determines to switch the terminal to a candidate cell based on the terminal's measurement report, the first node sends the corresponding TA value of the candidate cell to the terminal.

[0347] For example, if the first node determines to switch the terminal to the first cell according to the measurement report, it may determine the TA value corresponding to the first cell in the second information according to the identifier corresponding to the first cell, and include the TA value in the first information.

[0348] In some embodiments, the first information may be "Cell switch commd", "cell switching instruction", "TA indication information", etc. The embodiment of the present disclosure does not limit the name of the first information.

[0349] In some embodiments, the terminal receives the first information sent by the first node. Optionally, the terminal executes step S2109 in response to the first information. Optionally, after receiving the first information, the terminal executes step S2109.

[0350] In some embodiments, one or more of the above steps S2106 to S2108 may be a process of negotiating an Early TA value.

[0351] In some embodiments, the Early TA value negotiation may include at least one of the following: Early TA value negotiation in the MCG LTM scenario; Early TA value negotiation in the MN-initiated SCG LTM scenario; and Early TA value negotiation in the SN-initiated SCG LTM scenario. The Early TA value negotiation process in each scenario can be described in detail with reference to the embodiments shown in FIG. 7F to FIG. 7G , and is not further described here.

[0352] Step S2109: The terminal performs cell handover to the first cell.

[0353] In some embodiments, the terminal performs a cell handover to the first cell based on the first information. Optionally, the terminal performs a cell handover to the first cell based on the TA value of the first cell. Optionally, the terminal switches the serving cell to the first cell based on the TA value of the first cell. Optionally, the terminal switches the serving node to the second node based on the TA value of the first cell.

[0354] In some embodiments, the names of information, etc. are not limited to the names described in the embodiments, and terms such as "information", "message", "signal", "signaling", "report", "configuration", "indication", "instruction", "command", "channel", "parameter", "domain", "field", "symbol", "symbol", "codeword", "codebook", "codeword", "codepoint", "bit", "data", "program", and "chip" can be used interchangeably.

[0355] In some embodiments, terms such as "uplink", "uplink", "physical uplink" can be interchangeable with each other, and terms such as "downlink", "downlink", "physical downlink" can be interchangeable with each other, and terms such as "side", "sidelink", "side communication", "sidelink communication", "direct connection", "direct link", "direct communication", "direct link communication" can be interchangeable with each other.

[0356] In some embodiments, the terms "downlink control information (DCI)", "downlink (DL) assignment", "DL DCI", "uplink (UL) grant", "UL DCI" and the like may be used interchangeably.

[0357] In some embodiments, terms such as "physical downlink shared channel (PDSCH)" and "DL data" can be used interchangeably, and terms such as "physical uplink shared channel (PUSCH)" and "UL data" can be used interchangeably.

[0358] In some embodiments, the terms "radio", "wireless", "radio access network (RAN)", "access network (AN)", "RAN-based" and the like may be used interchangeably.

[0359] In some embodiments, terms such as "moment", "time point", "time", and "time position" can be replaced with each other, and terms such as "duration", "period", "time window", "window", and "time" can be replaced with each other.

[0360] In some embodiments, the terms "component carrier (CC)", "cell", "frequency carrier", "carrier frequency" and the like can be used interchangeably.

[0361] In some embodiments, terms such as "resource block (RB)", "physical resource block (PRB)", "sub-carrier group (SCG)", "resource element group (REG)", "PRB pair", "RB pair", "resource element (RE)", and "sub-carrier" can be used interchangeably.

[0362] In some embodiments, "obtain", "get", "get", "receive", "transmit", "bidirectional transmission", "send and / or receive" can be interchangeable, and can be interpreted as receiving from other entities, obtaining from protocols, obtaining from higher layers, obtaining by self-processing, autonomous implementation, etc.

[0363] In some embodiments, terms such as "send", "transmit", "report", "download", "transmit", "bidirectional transmission", "send and / or receive" can be used interchangeably.

[0364] In some embodiments, terms such as "certain", "preset", "preset", "setting", "indicated", "some", "any", and "first" can be interchangeable. "Specific A", "preset A", "preset A", "setting A", "indicated A", "some A", "any A", and "first A" can be interpreted as A pre-specified in a protocol, etc., or as A obtained through setting, configuration, or indication, etc., or as specific A, some A, any A, or first A, etc., but not limited to this.

[0365] In some embodiments, the determination or judgment can be performed by a value represented by 1 bit (0 or 1), or by a true or false value (Boolean value) represented by true or false, or by comparison of numerical values ​​(for example, comparison with a predetermined value), but is not limited thereto.

[0366] In some embodiments, "not expecting to receive" can be interpreted as not receiving on time domain resources and / or frequency domain resources, or as not performing subsequent processing on the data after receiving it; "not expecting to send" can be interpreted as not sending, or as sending but not expecting the recipient to respond to the content sent.

[0367] The communication method involved in the embodiments of the present disclosure may include at least one of steps S2101 to S2109. For example, step S2101 may be implemented as an independent embodiment, step S2102 may be implemented as an independent embodiment, step S2107 may be implemented as an independent embodiment, step S2101 and step S2102 may be implemented as independent embodiments, steps S2101 to S2104 may be implemented as an independent embodiment, and steps S2106 to S2107 may be implemented as independent embodiments, but are not limited thereto.

[0368] In some embodiments, steps S2101 to S2109 may be executed in a swapped order or simultaneously.

[0369] In some embodiments, steps S2102 to S2109 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0370] In some embodiments, steps S2101 to S2107 and step S2109 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0371] In some embodiments, steps S2101 to S2106 and steps S2107 to S2108 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0372] In some embodiments, reference may be made to other optional implementations described before or after the description corresponding to FIG. 2 .

[0373] FIG3A is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG2 , the embodiment of the present disclosure relates to a communication method (first node side), the method comprising:

[0374] Step S3101, sending the fourth information.

[0375] The optional implementation of step S3101 can refer to the optional implementation of step S2101 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0376] In some embodiments, the first node sends the fourth information to the second node, but is not limited thereto, and the fourth information may also be sent to other entities.

[0377] Step S3102, obtain the fifth information.

[0378] The optional implementation of step S3102 can refer to the optional implementation of step S2102 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0379] In some embodiments, the first node receives the fifth information sent by the second node, but is not limited thereto and may also receive the fifth information sent by other entities.

[0380] In some embodiments, the first node obtains fifth information specified by the protocol.

[0381] In some embodiments, the first node obtains the fifth information from an upper layer(s).

[0382] In some embodiments, the first node performs processing to obtain the fifth information.

[0383] In some embodiments, step S3102 is omitted, and the first node autonomously implements the function indicated by the fifth information, or the above function is default or by default.

[0384] Step S3103, sending the sixth information.

[0385] The optional implementation of step S3103 can refer to the optional implementation of step S2103 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0386] In some embodiments, the first node sends the third information to the second node, but is not limited thereto, and the third information may also be sent to other entities.

[0387] Step S3104, obtain the seventh information.

[0388] The optional implementation of step S3104 can refer to the optional implementation of step S2104 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0389] In some embodiments, the first node receives the seventh information sent by the second node, but is not limited thereto, and may also receive the seventh information sent by other entities.

[0390] In some embodiments, the first node obtains seventh information specified by the protocol.

[0391] In some embodiments, the first node obtains the seventh information from an upper layer(s).

[0392] In some embodiments, the first node performs processing to obtain the seventh information.

[0393] In some embodiments, step S3104 is omitted, and the first node autonomously implements the function indicated by the seventh information, or the above function is default or by default.

[0394] Step S3105, sending the eighth information.

[0395] The optional implementation of step S3105 can refer to the optional implementation of step S2105 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0396] In some embodiments, the first node sends the eighth information to the terminal, but is not limited thereto, and the eighth information may also be sent to other entities.

[0397] Step S3106, obtaining the second information.

[0398] The optional implementation of step S3104 can refer to the optional implementation of step S2107 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0399] In some embodiments, the first node receives the second information sent by the second node, but is not limited thereto and may also receive the second information sent by other entities.

[0400] In some embodiments, the first node obtains second information specified by the protocol.

[0401] In some embodiments, the first node obtains the second information from an upper layer(s).

[0402] In some embodiments, the first node performs processing to obtain the second information.

[0403] In some embodiments, step S3106 is omitted, and the first node autonomously implements the function indicated by the second information, or the above function is default or by default.

[0404] Step S3107, sending the first information.

[0405] The optional implementation of step S3107 can refer to the optional implementation of step S2108 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0406] In some embodiments, the first node sends the first information to the terminal, but is not limited thereto, and the first information may also be sent to other entities.

[0407] The communication method involved in the embodiments of the present disclosure may include at least one of steps S3101 to S3107. For example, step S3101 may be implemented as an independent embodiment, step S3106 may be implemented as an independent embodiment, step S3107 may be implemented as an independent embodiment, step S3101 and step S3102 may be implemented as independent embodiments, steps S3101 to S3104 may be implemented as an independent embodiment, and steps S3106 to S3107 may be implemented as independent embodiments, but the present invention is not limited thereto.

[0408] In some embodiments, steps S3102 to S3107 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0409] In some embodiments, steps S3101 to S3106 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0410] In some embodiments, steps S3101 to S3104 and step S3106 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0411] FIG3B is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG3B , the embodiment of the present disclosure relates to a communication method (first node side), the method comprising:

[0412] Step S3201, sending the fourth information.

[0413] Optional implementations of step S3201 can be found in step S2101 of FIG. 2 , optional implementations of step S3101 of FIG. 3A , and other related parts in the embodiments involved in FIG. 2 and FIG. 3A , which will not be described in detail here.

[0414] Step S3202, obtain the fifth information.

[0415] Optional implementations of step S3202 can be found in step S2102 of FIG. 2 , optional implementations of step S3102 of FIG. 3A , and other related parts in the embodiments involved in FIG. 2 and FIG. 3A , which will not be described in detail here.

[0416] Step S3203, sending the sixth information.

[0417] Optional implementations of step S3203 may refer to step S2103 in FIG. 2 , optional implementations of step S3103 in FIG. 3A , and other related parts in the embodiments involved in FIG. 2 and FIG. 3A , which will not be described in detail here.

[0418] Step S3204, obtain the seventh information.

[0419] Optional implementations of step S3204 can be found in step S2104 of FIG. 2 , optional implementations of step S3104 of FIG. 3A , and other related parts in the embodiments involved in FIG. 2 and FIG. 3A , which will not be described in detail here.

[0420] Step S3205, sending the first information.

[0421] The optional implementation of step S3205 can refer to the optional implementation of step S2108 in Figure 2, step S3107 in Figure 3A, and other related parts in the embodiments involved in Figures 2 and 3A, which will not be repeated here.

[0422] The communication method involved in the embodiments of the present disclosure may include at least one of steps S3201 to S3205. For example, step S3201 may be implemented as an independent embodiment, step S3203 may be implemented as an independent embodiment, step S3205 may be implemented as an independent embodiment, step S3201 and step S3202 may be implemented as independent embodiments, steps S3203 to S3204 may be implemented as an independent embodiment, and steps S3204 to S3205 may be implemented as independent embodiments, but the present invention is not limited thereto.

[0423] In some embodiments, steps S3202 to S3205 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0424] In some embodiments, steps S3201 to S3204 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0425] In some embodiments, steps S3201 to S3203 and step S3205 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0426] In some embodiments, the above steps S3201 to S3205 may be combined with at least one of steps S3101 to S3107 in Figure 3A. For example, steps S3201 to S3205 may be combined with step S3105.

[0427] FIG3C is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG3C , the embodiment of the present disclosure relates to a communication method (first node side), the method comprising:

[0428] Step S3301, obtain the second information.

[0429] The optional implementation of step S3301 can refer to step S2107 in Figure 2, the optional implementation of step S3106 in Figure 3A, and other related parts in the embodiments involved in Figures 2, 3A, and 3B, which will not be repeated here.

[0430] Step S3302, sending the first information.

[0431] The optional implementation of step S3302 can refer to the optional implementation of step S2108 in Figure 2, step S3107 in Figure 3A, step S3205 in Figure 3B, and other related parts in the embodiments involved in Figures 2, 3A, and 3B, which will not be repeated here.

[0432] The communication method involved in the embodiment of the present disclosure may include at least one of steps S3301 and S3302. For example, step S3301 may be implemented as an independent embodiment, and step S3302 may be implemented as an independent embodiment.

[0433] In an embodiment of the present disclosure, at least one of step S3301 and step S3302 can be combined with at least one of steps S3201 to S3205 in Figure 3B. For example, step S3301 can be combined with steps S3201 and S3202 in Figure 3B, but is not limited to this.

[0434] FIG3D is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG3D , the embodiment of the present disclosure relates to a communication method (first node side), the method comprising:

[0435] Step S3401, sending the first information.

[0436] The optional implementation of step S3401 can be found in the optional implementation of step S2108 in Figure 2, step S3107 in Figure 3A, step S3205 in Figure 3B, step S3302 in Figure 3C, and other related parts in the embodiments involved in Figures 2, 3A, 3B, and 3C, which will not be repeated here.

[0437] In some embodiments, the first node determines to perform cell switching to the first cell and sends first information to the terminal, where the first information is used to instruct the terminal to perform cell switching to the first cell. The first node is a node associated with the service cell of the terminal, and the service cell and the first cell correspond to different nodes.

[0438] In some embodiments, the method comprises:

[0439] The first node receives second information sent by the second node, where the second information includes timing advance (TA) related information of the first cell. The first information includes the TA value of the first cell, which is determined based on the second information. The second node is a node associated with the first cell.

[0440] In some embodiments, the first node is a source base station and the second node is a candidate base station; or,

[0441] The first node is the primary node MN, and the second node is the candidate secondary node SN; or

[0442] The first node is the serving SN, and the second node is the candidate SN.

[0443] In some embodiments, the TA-related information of the first cell includes at least one of the following corresponding to the first cell: a first cell identifier; a TA value; a preamble; a random access radio network temporary identifier RA-RNTI; and a second node identifier.

[0444] In some embodiments, the first node is a source base station and the second node is a candidate base station, or the first node is a MN and the second node is a candidate SN.

[0445] The second information is determined and sent by the second node according to the third information. The third information is sent by the terminal. The third information includes a random access RA preamble code.

[0446] In some embodiments, the first node is a serving SN and the second node is a candidate SN,

[0447] The first node receives the second information sent by the second node, including:

[0448] The first node receives second information sent by the MN, where the second information is determined by the second node according to third information and sent to the MN, and the third information is sent by the terminal, and includes an RA preamble code.

[0449] In some embodiments, the third information is sent by the terminal using a first random access RACH resource, where the first RACH resource is used for early synchronization between the first cell and the terminal.

[0450] In some embodiments, the method comprises:

[0451] The first node sends fourth information to the second node, where the fourth information is used to instruct the second node to determine a first random access channel (RACH) resource, where the second node is associated with the first cell, and the first RACH resource is used for early synchronization between the first cell and the terminal.

[0452] The first node receives fifth information sent by the second node, where the fifth information is used to indicate the first RACH resource.

[0453] In some embodiments, the method comprises:

[0454] The first node sends eighth information to the terminal, where the eighth information is used to indicate the first RACH resource.

[0455] In some embodiments,

[0456] The fourth information includes a first configuration list, where the first configuration list is used to indicate a second RACH resource that has been configured by the first node, where the second RACH resource is used for early synchronization between at least one second cell and the terminal, and the fourth information is used to instruct the second node to determine the first RACH resource based on the second RACH resource.

[0457] And / or, the method comprises:

[0458] The first node sends sixth information to the second node, where the sixth information includes the first configuration list, and the sixth information is used to instruct the second node to update the first RACH resource according to the second RACH resource.

[0459] In some embodiments, the first node sends sixth information to the second node, including:

[0460] The first node determines that there is a conflict between the first RACH resource and the second RACH resource, and sends sixth information to the second node.

[0461] In some embodiments, the method comprises:

[0462] The first node receives seventh information sent by the second node, where the seventh information is used to indicate the updated first RACH resource.

[0463] In some embodiments, the first configuration list includes at least one of the following:

[0464] a node identifier of a third node, where the third node is a node associated with the second cell;

[0465] a cell identifier of the second cell;

[0466] A configuration identifier corresponding to the second cell;

[0467] Configuration of the RACH resource corresponding to the configuration identifier.

[0468] FIG4A is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG4A , the embodiment of the present disclosure relates to a communication method (second node side), the method comprising:

[0469] Step S4101, obtain the fourth information.

[0470] The optional implementation of step S4101 can refer to the optional implementation of step S2101 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0471] In some embodiments, the second node receives the fourth information sent by the first node, but is not limited thereto and may also receive the fourth information sent by other entities.

[0472] In some embodiments, the second node obtains fourth information specified by the protocol.

[0473] In some embodiments, the second node obtains the fourth information from an upper layer(s).

[0474] In some embodiments, the second node performs processing to obtain the fourth information.

[0475] In some embodiments, step S4101 is omitted, and the second node autonomously implements the function indicated by the fourth information, or the above function is default or by default.

[0476] Step S4102, sending the fifth information.

[0477] The optional implementation of step S4102 can refer to the optional implementation of step S2102 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0478] In some embodiments, the second node sends the fifth information to the first node, but is not limited thereto, and the fifth information may also be sent to other entities.

[0479] Step S4103, obtain sixth information.

[0480] The optional implementation of step S4103 can refer to the optional implementation of step S2103 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0481] In some embodiments, the second node receives the sixth information sent by the first node, but is not limited thereto and may also receive the sixth information sent by other entities.

[0482] In some embodiments, the second node obtains sixth information specified by the protocol.

[0483] In some embodiments, the second node obtains the sixth information from an upper layer(s).

[0484] In some embodiments, the second node performs processing to obtain the sixth information.

[0485] In some embodiments, step S4103 is omitted, and the second node autonomously implements the function indicated by the sixth information, or the above function is default or by default.

[0486] Step S4104, sending the seventh information.

[0487] The optional implementation of step S4104 can refer to the optional implementation of step S2104 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0488] In some embodiments, the second node sends the seventh information to the first node, but is not limited thereto, and the seventh information may also be sent to other entities.

[0489] Step S4105, obtain third information.

[0490] The optional implementation of step S4105 can refer to the optional implementation of step S2106 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0491] In some embodiments, the second node receives the third information sent by the terminal, but is not limited thereto, and may also receive the third information sent by other entities.

[0492] In some embodiments, the second node obtains third information specified by the protocol.

[0493] In some embodiments, the second node obtains the third information from an upper layer(s).

[0494] In some embodiments, the second node performs processing to obtain the third information.

[0495] In some embodiments, step S4105 is omitted, and the second node autonomously implements the function indicated by the third information, or the above function is default or by default.

[0496] Step S4106, sending the second information.

[0497] The optional implementation of step S4106 can refer to the optional implementation of step S2107 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0498] In some embodiments, the second node sends the second information to the first node, but is not limited thereto, and the second information may also be sent to other entities.

[0499] The communication method involved in the embodiments of the present disclosure may include at least one of steps S4101 to S4106. For example, step S4102 may be implemented as an independent embodiment, step S4103 may be implemented as an independent embodiment, step S4106 may be implemented as an independent embodiment, step S4101 and step S4102 may be implemented as independent embodiments, steps S4101 to S4104 may be implemented as an independent embodiment, and steps S4106 to S4107 may be implemented as independent embodiments, but are not limited thereto.

[0500] In some embodiments, steps S4102 to S4106 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0501] In some embodiments, steps S4101 to S4104 and step S4106 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0502] FIG4B is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG4B , the embodiment of the present disclosure relates to a communication method (second node side), the method comprising:

[0503] Step S4201, obtain the fourth information.

[0504] The optional implementation of step S4201 can refer to the optional implementation of step S2101 in Figure 2, step S4101 in Figure 4A and other related parts in the embodiments involved in Figures 2 and 4A, which will not be repeated here.

[0505] Step S4202, sending the fifth information.

[0506] The optional implementation of step S4202 can refer to the optional implementation of step S2102 in Figure 2, step S4102 in Figure 4A and other related parts in the embodiments involved in Figures 2 and 4A, which will not be repeated here.

[0507] The communication method involved in the embodiment of the present disclosure may include at least one of steps S4201 and S4202. For example, step S4101 may be implemented as an independent embodiment, and step S4102 may be implemented as an independent embodiment.

[0508] FIG4C is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG4C , the embodiment of the present disclosure relates to a communication method (second node side), the method comprising:

[0509] Step S4301, obtain third information.

[0510] The optional implementation of step S4301 can refer to the optional implementation of step S2106 in Figure 2, step S4105 in Figure 4A and other related parts in the embodiments involved in Figures 2, 4A and 4B, which will not be repeated here.

[0511] Step S4302, sending the second information.

[0512] The optional implementation of step S4302 can refer to the optional implementation of step S2107 in Figure 2, step S4106 in Figure 4A and other related parts in the embodiments involved in Figures 2, 4A and 4B, which will not be repeated here.

[0513] The communication method involved in the embodiment of the present disclosure may include at least one of steps S4301 and S4302. For example, step S4301 may be implemented as an independent embodiment, and step S4302 may be implemented as an independent embodiment.

[0514] In the embodiment of the present disclosure, step S4301 and step S4302 may be combined with at least one step in Figure 4A. For example, step S4301 and step S4302 may be combined with step S4103 and step S4104, or may be combined with step S4105 and step S4106, but the present invention is not limited thereto.

[0515] FIG4D is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG4D , the embodiment of the present disclosure relates to a communication method (second node side), the method comprising:

[0516] Step S4401, sending the second information.

[0517] The optional implementation of step S4401 can refer to the optional implementation of step S2107 in Figure 2, step S4106 in Figure 4A, step S4302 in Figure 4C and other related parts in the embodiments involved in Figures 2, 4A, 4B and 4C, which will not be repeated here.

[0518] In some embodiments, the second node sends second information to the first node, the second information including timing advance TA-related information of the first cell, the first node is the node associated with the service cell of the terminal, the second node is the node associated with the first cell, and the first cell and the service cell correspond to different nodes.

[0519] In some embodiments, the first node is a source base station and the second node is a candidate base station; or,

[0520] The first node is a primary node MN, and the second node is a candidate secondary node SN; or

[0521] The first node is a serving secondary node SN, and the second node is a candidate SN.

[0522] In some embodiments, the TA-related information of the first cell includes at least one of the following corresponding to the first cell: a first cell identifier; a TA value; a preamble; an RA-RNTI; and a second node identifier.

[0523] In some embodiments, the first node is a source gNB and the second node is a candidate gNB, or the first node is a MN and the second node is a candidate SN,

[0524] The second node sends second information to the first node, including:

[0525] The second node receives third information sent by the terminal, where the third information includes a random access RA preamble code;

[0526] The second node determines, based on the third information, and sends the second information to the first node.

[0527] In some embodiments, the first node is a serving SN and the second node is a candidate SN,

[0528] The second node sends second information to the first node, including:

[0529] The second node sends second information to the first node through the MN. The second information is determined by the second node according to third information. The third information is sent by the terminal and includes an RA preamble code.

[0530] In some embodiments, the third information is sent by the terminal using a first random access RACH resource, where the first RACH resource is used for early synchronization between the first cell and the terminal.

[0531] In some embodiments, the method comprises:

[0532] The second node receives the fourth information sent by the first node;

[0533] The second node determines a first RACH resource, where the first RACH resource is used for early synchronization between the first cell and the terminal;

[0534] The second node sends fifth information to the first node, where the fifth information is used to indicate the first RACH resource.

[0535] In some embodiments, the fourth information includes a first configuration list, the first configuration list is used to indicate a second RACH resource that has been configured by the first node, the second RACH resource is used for early synchronization of at least one second cell with the terminal, and the fourth information is used to instruct the second node to determine the first RACH resource based on the second RACH resource;

[0536] And / or, the second node determines the first RACH resource including: the second node receives sixth information sent by the first node, where the sixth information includes the first configuration list; and the third node updates the first RACH resource according to the second RACH resource.

[0537] In some embodiments, the method comprises:

[0538] The second node sends seventh information to the first node, where the seventh information is used to indicate the updated first RACH resource.

[0539] In some embodiments, the first configuration list includes at least one of the following:

[0540] a node identifier of a third node, where the third node is a node associated with the second cell;

[0541] a cell identifier of the second cell;

[0542] A configuration identifier corresponding to the second cell;

[0543] Configuration of the RACH resource corresponding to the configuration identifier.

[0544] FIG5A is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG5A , the embodiment of the present disclosure relates to a communication method (terminal side), the method comprising:

[0545] Step S5101, obtain the eighth information.

[0546] The optional implementation of step S5101 can refer to the optional implementation of step S2105 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0547] In some embodiments, the terminal receives the eighth information sent by the first node, but is not limited thereto, and may also receive the eighth information sent by other entities.

[0548] In some embodiments, the terminal obtains eighth information specified by the protocol.

[0549] In some embodiments, the terminal obtains the eighth information from an upper layer(s).

[0550] In some embodiments, the terminal performs processing to obtain the eighth information.

[0551] In some embodiments, step S5101 is omitted, and the terminal autonomously implements the function indicated by the eighth information, or the above function is default or by default.

[0552] Step S5102, sending the third information.

[0553] The optional implementation of step S5102 can refer to the optional implementation of step S2106 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0554] In some embodiments, the terminal sends the third information to the second node, but is not limited thereto, and the third information may also be sent to other entities.

[0555] Step S5103, obtain first information.

[0556] The optional implementation of step S5103 can refer to the optional implementation of step S2108 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0557] In some embodiments, the terminal receives the first information sent by the first node, but is not limited thereto, and may also receive the first information sent by other entities.

[0558] In some embodiments, the terminal obtains first information specified by the protocol.

[0559] In some embodiments, the terminal obtains the first information from an upper layer(s).

[0560] In some embodiments, the terminal performs processing to obtain the first information.

[0561] In some embodiments, step S5103 is omitted, and the terminal autonomously implements the function indicated by the first information, or the above function is default or by default.

[0562] Step S5104: Perform cell handover to the first cell.

[0563] The optional implementation of step S5104 can refer to the optional implementation of step S2109 in Figure 2 and other related parts in the embodiment involved in Figure 2, which will not be repeated here.

[0564] The communication method involved in the embodiments of the present disclosure may include at least one of steps S5101 to S5104. For example, step S5101 can be implemented as an independent embodiment, step S5102 can be implemented as an independent embodiment, step S5103 can be implemented as an independent embodiment, step S5101 and step S5102 can be implemented as independent embodiments, steps S5102 to S5103 can be implemented as an independent embodiment, and steps S5103 to S5104 can be implemented as independent embodiments, but are not limited thereto.

[0565] In some embodiments, steps S5101 to S5103 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0566] In some embodiments, steps S5101 to S5102 and step S5104 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0567] In some embodiments, steps S5102 to S5104 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0568] FIG5B is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG5B , the embodiment of the present disclosure relates to a communication method (terminal side), the method comprising:

[0569] Step S5201, sending the third information.

[0570] The optional implementation of step S5201 can refer to the optional implementation of step S2106 in Figure 2, step S5102 in Figure 5A and other related parts in the embodiments involved in Figures 2 and 5A, which will not be repeated here.

[0571] Step S5202, obtain first information.

[0572] The optional implementation of step S5202 can refer to the optional implementation of step S2108 in Figure 2, step S5103 in Figure 5A and other related parts in the embodiments involved in Figures 2 and 5A, which will not be repeated here.

[0573] Step S5203: Perform cell handover to the first cell.

[0574] The optional implementation of step S5203 can refer to the optional implementation of step S2109 in Figure 2, step S5104 in Figure 5A and other related parts in the embodiments involved in Figures 2 and 5A, which will not be repeated here.

[0575] The communication method involved in the embodiments of the present disclosure may include at least one of steps S5201 to S5203. For example, step S5201 can be implemented as an independent embodiment, step S5202 can be implemented as an independent embodiment, step S5203 can be implemented as an independent embodiment, step S5201 and step S5202 can be implemented as independent embodiments, and steps S5202 to S5203 can be implemented as independent embodiments.

[0576] In some embodiments, steps S5201 to S5202 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0577] In some embodiments, steps S5202 to S5203 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0578] In some embodiments, step S5201 and step S5203 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0579] FIG5C is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG5C , the embodiment of the present disclosure relates to a communication method (terminal side), the method comprising:

[0580] Step S5301, obtain first information.

[0581] The optional implementation of step S5301 can refer to the optional implementation of step S2108 in Figure 2, step S5103 in Figure 5A, step S5202 in Figure 5B and other related parts in the embodiments involved in Figures 2, 5A and 5C, which will not be repeated here.

[0582] Step S5302: Perform cell handover to the first cell.

[0583] The optional implementation of step S5302 can refer to the optional implementation of step S2109 in Figure 2, step S5104 in Figure 5A, step S5203 in Figure 5B and other related parts in the embodiments involved in Figures 2, 5A and 5C, which will not be repeated here.

[0584] In some embodiments, the terminal receives first information sent by a first node, where the first node is a node associated with a serving cell of the terminal;

[0585] The terminal performs cell handover to a first cell according to the first information, where the first cell and the serving cell correspond to different nodes.

[0586] In some embodiments, the method comprises:

[0587] The terminal performs cell switching to the first cell based on the TA value of the first cell in the first information. The TA value of the first cell is determined by the first node based on the second information. The second information is sent by the second node, and the second information includes TA-related information of the first cell. The second node is the node associated with the first cell.

[0588] In some embodiments, the first node is a source base station and the second node is a candidate base station; or,

[0589] The first node is a primary node MN, and the second node is a candidate secondary node SN; or

[0590] The first node is the serving SN, and the second node is the candidate SN.

[0591] In some embodiments, the TA-related information of the first cell includes at least one of the following corresponding to the first cell: a first cell identifier; a TA value; a preamble; an RA-RNTI; and a second node identifier.

[0592] In some embodiments, the method comprises:

[0593] The terminal sends third information to the second node, where the third information is used by the second node to determine the second information, and the third information includes a random access RA preamble code.

[0594] In some embodiments, the third information is sent by the terminal using a first random access RACH resource, where the first RACH resource is used for early synchronization between the first cell and the terminal.

[0595] In some embodiments, the method comprises:

[0596] The terminal receives eighth information sent by the first node, where the eighth information is used to indicate a first RACH resource, and the first RACH resource is used for early synchronization between the first cell and the terminal.

[0597] Figure 6 is an interactive diagram of a communication method according to an embodiment of the present disclosure. As shown in Figure 6, the embodiment of the present disclosure relates to a communication method, and the method includes:

[0598] Step S6101: The second node sends second information to the first node.

[0599] For the optional implementation of step S6101, please refer to the optional implementation of step S2107 in Figure 2, step S3106 in Figure 3A, step S3301 in Figure 3C, step S4106 in Figure 4A, step S4302 in Figure 4C, and step S4401 in Figure 4D, as well as other related parts in the embodiments involved in Figures 2, 3A, 3B, 3C, 3D, 4A, 4B, 4C, 4D, 5A, 5B, and 5C, which will not be repeated here.

[0600] Step S6102: The first node sends first information to the terminal.

[0601] For the optional implementation of step S6101, please refer to step S2108 of Figure 2, step S3107 of Figure 3A, step S3205 of Figure 3B, step S3302 of Figure 3C, step S3401 of Figure 3D, step S5103 of Figure 5A, step S5202 of Figure 5B, and step S5301 of Figure 5C, as well as other related parts in the embodiments involved in Figures 2, 3A, 3B, 3C, 3D, 4A, 4B, 4C, 4D, 5A, 5B, and 5C, which will not be repeated here.

[0602] Step S6103: The terminal performs handover to the first cell according to the first information.

[0603] For the optional implementation of step S6101, please refer to the optional implementation of step S2109 in Figure 2, step S5104 in Figure 5A, step S5203 in Figure 5B, and step S5302 in Figure 5C, as well as other related parts in the embodiments involved in Figures 2, 3A, 3B, 3C, 3D, 4A, 4B, 4C, 4D, 5A, 5B, and 5C, which will not be repeated here.

[0604] FIG7A is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG7A , the embodiment of the present disclosure relates to a communication method, and the method includes:

[0605] Step S7101: The serving node sends RACH resource request indication information.

[0606] In some embodiments, the serving node sends an indication message of a RACH resource request, instructing the candidate node to generate RACH resources for Early RACH for the corresponding candidate cell. After receiving the corresponding request message, if the candidate node supports the relevant function, the candidate node may include the corresponding RACH resource configuration of the corresponding candidate cell in the corresponding confirmation message sent to the serving node.

[0607] In some embodiments, for MCG LTM, the serving node is the source gNB and the candidate node is the candidate gNB.

[0608] In some embodiments, to avoid different candidate cells being configured with the same RACH resources, the serving node may send the RACH resources configured by other candidate nodes for their corresponding candidate cells, thereby avoiding the candidate nodes preparing the same RACH resource configuration.

[0609] In some embodiments, for MCG LTM, in the preparation phase of preparing the LTM candidate configuration, the source gNB sends a first message to the candidate gNB, where the first message includes information related to requesting Early Sync.

[0610] In some embodiments, the first message may be a Handover Request message or other Xn message for requesting LTM.

[0611] In some embodiments, the information related to requesting Early Sync includes but is not limited to one or more of the following: indication information for requesting related RACH resources. When the indication information indicates "True" or a specific value, or is configured, it means that the source gNB requests the candidate gNB to prepare corresponding RACH resources for Early sync for the candidate cell included in the first message.

[0612] In some embodiments, after receiving the first message sent by the source gNB, if the information related to requesting Early Sync contained in the first message indicates that corresponding RACH resources are to be requested for the corresponding candidate cell, then if the candidate gNB supports the relevant function, the candidate gNB may include the corresponding RACH resources in the confirmation message of the first message sent to the source gNB.

[0613] In some embodiments, the confirmation message of the first message may be a Handover Request Acknowledge message or other confirmation message for requesting an LTM message.

[0614] In some embodiments, to prevent different candidate gNBs from generating the same RACH resources for Early Sync for their corresponding candidate cells, the candidate gNB also needs to know the RACH resources for Early Sync prepared by other candidate gNBs for their corresponding candidate cells. Therefore, the following two optional solutions can be used to avoid Early Sync RACH resource conflicts:

[0615] Solution 1: The source gNB includes a list of Early Sync resources configured for candidate cells (corresponding to other candidate gNBs) in the first message sent to the candidate gNB to request Early Sync. This allows the candidate gNB to avoid conflicts with these already configured resources when generating the corresponding RACH resources.

[0616] Optionally, since the source gNB may request multiple candidate gNBs simultaneously, after receiving an acknowledgment of the first message from the candidate gNB, the source gNB may send a second message to the candidate gNB containing a list of Early Sync resources configured for the candidate cells (corresponding to the other candidate gNBs). Depending on the implementation, if the source gNB detects a RACH resource conflict, it may send the second message to the candidate gNB with the conflicting resources, if necessary. The candidate gNB may update the RACH resources generated for the corresponding candidate cell based on the second message to avoid the conflict, and send the second message to the source gNB via an acknowledgment of the second message.

[0617] Solution 2: (RACH resources of other candidate cells are not included in the first message) After receiving the confirmation message of the first message from the candidate gNB, the source gNB sends a second message to the candidate gNB with the configuration list of Early Sync resources configured for (other) candidate cells (depending on the implementation, if the source gNB finds a conflict in RACH resources, it can send the second message to the candidate gNB with resource conflicts if necessary). The candidate gNB can update the RACH resources generated for the corresponding candidate cell based on the second message to avoid the conflict, and send the second message to the source gNB via confirmation message.

[0618] In some embodiments, the second message may be the same message as the first message or a different message, such as an Xn message that transmits LTM-related information; the confirmation message of the second message may be the same message as the confirmation message of the first message or a different message, such as a confirmation message of the Xn message that transmits LTM-related information.

[0619] In some embodiments, the configuration list of Early Sync resources configured for other candidate cells may include IDs (eg, CGIs) of multiple candidate cells, and / or LTM configuration identifiers and corresponding RACH resource configurations.

[0620] In some embodiments, the indication information for requesting relevant RACH resources, the corresponding RACH resources of the candidate cell generated by the candidate gNB, and the list of RACH resources for Early Sync generated by other candidate cells can be directly included in the above-mentioned Xn message or indicated through the corresponding inter-node RRC message.

[0621] In some embodiments, the indication information for requesting related RACH resources and the RACH resources for Early Sync (including: the RACH resources corresponding to the candidate cell generated by the candidate gNB, and the list of RACH resources for Early Sync generated by other candidate cells) can be represented by the EarlyUL-SyncConfig IE or included in an inter-node RRC message, such as Handover Preparation or Handover Command.

[0622] In some embodiments, for SCG LTM, the serving node may be a MN and the candidate node may be a candidate SN.

[0623] In some embodiments, the MN sends a first message to the candidate SN, where the first message includes information related to requesting Early Sync.

[0624] In some embodiments, the first message may be: an SN Addition Request message or other Xn message for requesting LTM.

[0625] In some embodiments, the information related to requesting Early Sync includes, but is not limited to, one or more of the following:

[0626] Indication information for requesting related RACH resources. When the indication information indicates "True" or a specific value, or is configured, it means that the source gNB requests the candidate gNB to prepare corresponding RACH resources for Early Sync for one or more of the recommended candidate cells in the list of recommended candidate cells included in the first message;

[0627] The information related to requesting Early Sync (eg, the indication information of requesting related RACH resources) may be per candidate cell or specific to the candidate SN. For example, each cell in the recommended candidate cells included in the first message corresponds to one indication information.

[0628] In some embodiments, after receiving the first message sent by the MN, if the information related to requesting Early Sync contained in the first message indicates a request to prepare corresponding RACH resources for the corresponding candidate cell, then if the candidate SN supports the relevant function, the candidate SN can include the corresponding RACH resources corresponding to the corresponding candidate cell in the confirmation message of the first message sent to the MN.

[0629] In some embodiments, the confirmation message of the first message may be: an SN Addition Request Acknowledge message or other confirmation message for requesting an LTM message.

[0630] In some embodiments, to prevent different candidate SNs from generating the same RACH resources for Early Sync for their corresponding candidate cells, the candidate SN also needs to know the RACH resources for Early Sync prepared by other candidate SNs for their corresponding candidate cells. Therefore, the following two optional solutions can be used to avoid conflicts in Early Sync RACH resources:

[0631] Solution 1: The MN includes in the first message sent to the candidate SN for requesting Early Sync related information a configuration list of Early Sync resources configured for the candidate cells corresponding to (other) candidate SNs. In this way, when the candidate SN generates the corresponding RACH resources, it can avoid conflicts with these already configured resources.

[0632] Optionally, since the MN may request (MN triggered or S-SN triggered) multiple candidate SNs at the same time, after receiving the confirmation message of the first message replied by the candidate SN, the MN can send a second message to the candidate SN carrying the configuration list of Early Sync resources configured for the candidate cell corresponding to the (other) candidate SN (based on implementation, if the MN finds that there is a conflict of RACH resources, if necessary, the MN can send a second message to the candidate SN with the resource conflict), and the candidate SN can update the RACH resources generated for the corresponding candidate cell based on the second message to avoid conflict, and send it to the MN through a confirmation message of the second message.

[0633] Solution 2: (The RACH resources of other candidate cells are not carried in the first message) Therefore, after the MN receives the confirmation message of the first message replied by the candidate SN, the MN can send a second message to the candidate SN carrying the configuration list of Early Sync resources configured for the candidate cells corresponding to (other) candidate SNs (based on implementation, if the MN finds that there is a conflict of RACH resources, if necessary, the MN can send a second message to the candidate SN with resource conflict), and the candidate SN can update the RACH resources generated for the corresponding candidate cell based on the second message to avoid conflict, and send it to the MN through a confirmation message of the second message.

[0634] In some embodiments, the second message may be: SN Modification Request message or other Xn message for requesting LTM; the confirmation message of the first message may be: SN Modification Request Acknowledge message or other confirmation message for requesting LTM message.

[0635] In some embodiments, the confirmation message of the second message may be the same message as the confirmation message of the first message or a different message, such as confirmation information of an Xn message that transmits LTM-related information;

[0636] In some embodiments, the configuration list of Early Sync resources configured for the candidate cell may include IDs of multiple candidate SNs, IDs of candidate cells (eg, CGI), and / or LTM configuration identifiers and corresponding RACH resource configurations.

[0637] In some embodiments, the indication information for requesting relevant RACH resources, the RACH resources corresponding to one or more candidate cells generated by the candidate SN, and the list of RACH resources for Early Sync generated by candidate cells corresponding to other candidate SNs can be directly included in the above-mentioned Xn message or indicated through the corresponding inter-node RRC message.

[0638] In some embodiments, the RACH resources for Early Sync (including: the RACH resources corresponding to the candidate cells generated by the candidate SN, and the list of RACH resources for Early Sync generated by other candidate cells) can be represented by the EarlyUL-SyncConfig IE or included in the inter-node RRC message, such as CG-CandidateList, CG-Config, and CG-ConfigInfo.

[0639] In an embodiment of the present disclosure, the first message may be the fourth information or part of the fourth information in some of the above-mentioned embodiments, the confirmation message of the first message may be the fifth information or part of the fifth information in some of the above-mentioned embodiments, the second message may be the sixth information or part of the sixth information in some of the above-mentioned embodiments, and the confirmation message of the second message may be the seventh information or part of the seventh information in some of the above-mentioned embodiments.

[0640] In the embodiments of the present disclosure, some or all of the steps and their optional implementations may be arbitrarily combined with some or all of the steps in other embodiments, or may be arbitrarily combined with the optional implementations of other embodiments.

[0641] FIG7B is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG7B , the embodiment of the present disclosure relates to a communication method, and the method includes:

[0642] Step S7201: After receiving the RA Preamble sent by the UE, the candidate node obtains the TA information of the corresponding candidate cell.

[0643] Step S7202: The candidate node sends the TA information corresponding to the candidate cell to the serving node.

[0644] Step S7203: The serving node triggers RACH-less LTM based on the TA information forwarded by the candidate node.

[0645] In some embodiments, after receiving the RA Preamble sent by the UE, the candidate node obtains the TA information of the corresponding candidate cell, and sends the TA information of the candidate cell to the serving node. The serving node triggers RACH-less LTM based on the TA information forwarded by the candidate node.

[0646] In some embodiments, for MCG LTM, the serving node is the source gNB and the candidate node is the candidate gNB. For SCG LTM, the serving node is the MN and / or S-SN and the candidate node is the candidate SN.

[0647] In some embodiments, for MCG LTM and MN / SN initiated SCG LTM, the candidate node needs to send TA-related information to the serving gNB or serving MN.

[0648] In some embodiments, for SN initiated SCG LTM, after receiving the TA information related to the corresponding candidate cell, the / MN needs to forward it to the S-SN, and the S-SN triggers the RACH-less LTM based on the TA information forwarded by the candidate node.

[0649] For MCG LTM:

[0650] In some embodiments, in step S7201, the UE performs the Early TA acquisition process and sends an RA Preamble to the candidate cell. The candidate gNB obtains the TA value corresponding to the corresponding candidate cell based on the received RA Preamble.

[0651] In some embodiments, in step S7202, the candidate gNB sends a first message to the source (current serving) gNB. The first message includes TA information corresponding to the corresponding candidate cell. The purpose of the first message is to enable the source gNB to send TA-related information to the terminal.

[0652] In some embodiments, the first message may be an existing Xn message, or a new Xn message, such as a first TA information transfer message.

[0653] In some embodiments, the TA information corresponding to the candidate cell includes but is not limited to one or more TA values ​​corresponding to one or more candidate cells, Preamble ID, RA-RNTI, and corresponding candidate gNB ID and other information.

[0654] In some embodiments, in addition to the TA information corresponding to the candidate cell, the first message may also include but is not limited to one or more of the following information: Xn message type; source gNB identifier, candidate gNB identifier, UE ID, such as the XnAP ID of the UE on the source gNB, and the XnAP ID of the UE on the candidate gNB.

[0655] In some embodiments, after receiving the first message, the source gNB, also known as the serving gNB, considers that the received information is TA information from the candidate cell indicated by the included candidate cell ID.

[0656] In some embodiments, in step S72023, the source gNB sends a Cell Switch Command to the UE, which includes the TA value of the candidate cell.

[0657] For MN initiated SCG LTM:

[0658] In some embodiments, in step S7201, the UE performs an Early TA acquisition process and sends an RA Preamble to the candidate cell. The candidate SN obtains a TA value corresponding to the corresponding candidate cell based on the received RA Preamble.

[0659] In some embodiments, in step S7202, the candidate SN sends a first message to the MN. The first message includes TA information corresponding to the corresponding candidate cell. The purpose of the first message is to enable the MN to send TA-related information to the terminal.

[0660] In some embodiments, the first message may be an existing Xn message, or a new Xn message, such as a second TA information transfer message.

[0661] In some embodiments, the TA information corresponding to the candidate cell includes but is not limited to one or more TA values ​​corresponding to one or more candidate cells, Preamble ID, RA-RNTI, and corresponding candidate SN ID and other information.

[0662] In some embodiments, in addition to the TA information corresponding to the candidate cell, the first message may also include but is not limited to one or more of the following information: Xn message type; MN identifier, candidate SN identifier, UE ID, such as the XnAP ID of the UE on the MN, and the XnAP ID of the UE on the SN.

[0663] In some embodiments, after receiving the first message, the MN considers that the received information is TA information from the candidate cell indicated by the included candidate cell ID.

[0664] In some embodiments, in step S7203, the MN sends a Cell Switch Command to the UE, which includes the TA value of the candidate cell.

[0665] For SN initiated SCG LTM:

[0666] In some embodiments, in step S7201, the UE performs an Early TA acquisition process and sends an RA Preamble to the candidate cell. The candidate SN obtains a TA value corresponding to the corresponding candidate cell based on the received RA Preamble.

[0667] In some embodiments, in step S7202, the candidate SN sends a first message to the MN, where the first message includes TA information corresponding to the corresponding candidate cell. The purpose of the first message is to enable the MN to send TA-related information to the source SN and the terminal.

[0668] In some embodiments, after receiving the TA information related to the candidate cell sent by the candidate SN, the MN forwards it to the source SN.

[0669] In some embodiments, after receiving the TA-related information forwarded by the MN, the serving SN considers that the received information is TA information from the candidate cell indicated by the included candidate cell ID.

[0670] In some embodiments, in step S7203, the SN sends a Cell Switch Command to the UE, which includes the TA value of the candidate cell.

[0671] In the embodiments of the present disclosure, the RA Preamble may be the third information or a part of the third information in some of the above embodiments, and the first message may be the second information or a part of the second information in some of the above embodiments.

[0672] In the embodiments of the present disclosure, some or all of the steps and their optional implementations may be arbitrarily combined with some or all of the steps in other embodiments, or may be arbitrarily combined with the optional implementations of other embodiments.

[0673] In combination with some optional implementations in the above embodiments, the embodiments of the present disclosure further provide interactive schematic diagrams of the communication method as shown in Figures 7C to 7H.

[0674] 7C and 7F may correspond to the MCG LTM, FIG. 7D and 7G may correspond to the MN imitated SCG LTM, and FIG. 7E and 7H may correspond to the SN initiated SCG LTM.

[0675] FIG7C is an interactive diagram of a communication method according to an embodiment of the present disclosure. As shown in FIG7C , the embodiment of the present disclosure relates to a communication method, and the method includes:

[0676] In step S7301, the terminal sends a measurement report to the source gNB.

[0677] In step S7302, the source gNB sends a Handover / LTM Request message to the candidate gNB.

[0678] In some embodiments, the Handover Request message or the LTM Request message may be the fourth information or a part of the fourth information described in some of the above embodiments.

[0679] In step S7303, the candidate gNB performs admission control.

[0680] In step S7304, the candidate gNB sends a Handover / LTM Request Acknowledge message to the source gNB.

[0681] In some embodiments, the Handover Request Acknowledge message or the LTM Request Acknowledge message may be the fifth information or a part of the fifth information described in some of the above embodiments.

[0682] In step S7305, the source gNB sends an LTM information transfer to the candidate gNB.

[0683] Step S7306: The candidate gNB sends an LTM information transfer Acknowledge message to the source gNB.

[0684] In step S7307, the source gNB sends an RRCConnectionReconfiguration message to the terminal.

[0685] In some embodiments, the RRCConnectionReconfiguration message may be the eighth information or a part of the eighth information described in some of the above embodiments.

[0686] In step S7308, the terminal sends an RRCConnectionReconfigurationComplete message to the source gNB.

[0687] In step S7309, the terminal performs early sync with the source gNB.

[0688] In some embodiments, the process from step S7301 to step S7308 may be a process of negotiating Early RACH resources, for example, it may be called negotiation of Early RACH resources for MCG LTM in a non-DC scenario.

[0689] In some embodiments, one or more steps from step S7301 to step S7308 are optional. For example, Early RACH resource negotiation may be performed in other ways, such as performing early synchronization based on Early RACH resources indicated by a higher layer or agreed upon in a protocol, or not performing Early RACH resource negotiation.

[0690] In the embodiments of the present disclosure, some or all of the steps and their optional implementations may be arbitrarily combined with some or all of the steps in other embodiments, or may be arbitrarily combined with the optional implementations of other embodiments.

[0691] FIG7D is an interactive diagram of a communication method according to an embodiment of the present disclosure. As shown in FIG7D , the embodiment of the present disclosure relates to a communication method, and the method includes:

[0692] Step S7401: The terminal sends a measurement report to the MN.

[0693] Step S7402: The MN sends an SN Addition Request message to the candidate SN.

[0694] In some embodiments, the SN Additon Request message may be the fourth message or the sixth message described in some of the above embodiments.

[0695] Step S7403: The candidate SN sends an SN Addition Request Acknowledge message to the MN.

[0696] In some embodiments, the SN Additon Request Acknowledge message may be the fifth message or the seventh message described in some of the above embodiments.

[0697] Step S7404: The MN sends an SN Modification Request to the candidate SN.

[0698] Step S7405: The candidate SN sends an SN Modification Request Acknowledge message to the MN.

[0699] Step S7406: The MN sends an RRCConnectionReconfiguration message to the terminal.

[0700] In some embodiments, the RRCConnectionReconfiguration message may be the eighth information described in some of the above embodiments.

[0701] Step S7407: The terminal sends an RRCConnectionReconfigurationComplete message to the MN.

[0702] In step S7408, the terminal performs early sync with the MN.

[0703] In some embodiments, the process from step S7401 to step S7407 may be a process of negotiating Early RACH resources, for example, it may be referred to as negotiation of Early RACH resources for SCG LTM initiated by an MN in a DC scenario.

[0704] In some embodiments, one or more steps from step S7401 to step S7407 are optional. For example, Early RACH resource negotiation may be performed in other ways, such as performing early synchronization based on Early RACH resources indicated by a higher layer or agreed upon in a protocol, or not performing Early RACH resource negotiation.

[0705] In the embodiments of the present disclosure, some or all of the steps and their optional implementations may be arbitrarily combined with some or all of the steps in other embodiments, or may be arbitrarily combined with the optional implementations of other embodiments.

[0706] FIG7E is an interactive diagram of a communication method according to an embodiment of the present disclosure. As shown in FIG7E , the embodiment of the present disclosure relates to a communication method, and the method includes:

[0707] Step S7501: The terminal sends a measurement report to the serving SN.

[0708] Step S7502: The serving SN sends an SN Change Required message to the MN.

[0709] Step S7503: The MN sends an SN Addition Request message to the candidate SN.

[0710] In some embodiments, the SN Change Required message and / or the SN Change Request message may be the fourth information described in some of the above embodiments.

[0711] Step S7504: The candidate SN sends an SN Addition Request Acknowledge message to the MN.

[0712] In some embodiments, the SN Additon Request Acknowledge message may be the fifth information described in some of the above embodiments.

[0713] Step S7505: The MN sends an SN Modification Request to the candidate SN.

[0714] Step S7506: The candidate SN sends an SN Modification Request Acknowledge message to the MN.

[0715] Step S7507: The MN sends an RRCConnectionReconfiguration message to the terminal.

[0716] The RRCConnectionReconfiguration message may include an MN RRCConnectionReconfiguration message and an SN RRCConnectionReconfiguration message.

[0717] In some embodiments, the RRCConnectionReconfiguration message may be the eighth information described in some of the above embodiments.

[0718] Step S7508: The terminal sends an RRCConnectionReconfigurationComplete message to the MN.

[0719] Step S7509: The terminal performs early sync with the serving SN.

[0720] In some embodiments, the Cell Switch Command may be the first information described in some of the above embodiments.

[0721] In some embodiments, the process from step S7501 to step S7509 may be a process of negotiating Early RACH resources, for example, it may be called negotiation of Early RACH resources for SCG LTM initiated by the SN in a DC scenario.

[0722] In some embodiments, one or more steps from step S7501 to step S7509 are optional. For example, Early RACH resource negotiation may be performed in other ways, such as performing early synchronization based on Early RACH resources indicated by a higher layer or agreed upon in a protocol, or not performing Early RACH resource negotiation.

[0723] In the embodiments of the present disclosure, some or all of the steps and their optional implementations may be arbitrarily combined with some or all of the steps in other embodiments, or may be arbitrarily combined with the optional implementations of other embodiments.

[0724] FIG7F is an interactive diagram of a communication method according to an embodiment of the present disclosure. As shown in FIG7E , an embodiment of the present disclosure relates to a communication method, the method comprising:

[0725] In step S7601, the terminal performs early TA acquisiton with the candidate gNB.

[0726] In some embodiments, early TA acqusiton can be a process in which the terminal sends the third information in some of the above embodiments (such as an RA preamble code) to the candidate gNB, and enables the terminal to receive the TA value corresponding to one or more candidate cells determined by the candidate gNB.

[0727] In step S7602, the candidate gNB sends a TA information transfer message to the source gNB.

[0728] In some embodiments, the TA information transfer message may be the second information or a part of the second information described in some of the above embodiments.

[0729] In step S7603, the source gNB sends a Cell Switch Command to the terminal.

[0730] In some embodiments, the Cell Switch Command may be the first information described in some of the above embodiments.

[0731] In some embodiments, the process from step S7601 to step S7602 may be a process of negotiating an Early TA value, for example, it may be called negotiation of an Early TA value of an MCG LTM in a non-DC scenario.

[0732] In some embodiments, one or more steps from step S7601 to step S7603 are optional. For example, the Early TA value may be negotiated in other ways, or the Early TA value may not be negotiated.

[0733] In some embodiments, steps S7601 to S7603 may be combined with some steps in the embodiment shown in FIG7C . For example, step S7309 in FIG7C may include steps S7601 to S7603 or may be replaced by steps S7601 to S7603.

[0734] In the embodiments of the present disclosure, some or all of the steps and their optional implementations may be arbitrarily combined with some or all of the steps in other embodiments, or may be arbitrarily combined with the optional implementations of other embodiments.

[0735] FIG7G is an interactive diagram of a communication method according to an embodiment of the present disclosure. As shown in FIG7G , the embodiment of the present disclosure relates to a communication method, and the method includes:

[0736] In step S7701, the terminal performs early TA acquisiton with the candidate SN.

[0737] In some embodiments, early TA acquisiton may be a process in which the terminal sends the third information in some of the above embodiments to the candidate SN, and enables the terminal to receive the TA value corresponding to one or more candidate cells determined by the candidate SN.

[0738] Step S7702: The candidate SN sends a TA information transfer message to the MN.

[0739] In some embodiments, the TA information transfer message may be the second information described in some of the above embodiments.

[0740] Step S7703: The MN sends a Cell Switch Command to the terminal.

[0741] In some embodiments, the Cell Switch Command may be the first information described in some of the above embodiments.

[0742] In some embodiments, the process from step S7701 to step S7702 may be a process of negotiating an Early TA value, for example, it may be referred to as a negotiation of an Early TA value of an SCG LTM initiated by an MN in a DC scenario.

[0743] In some embodiments, one or more steps from step S7701 to step S7702 are optional. For example, the Early TA value may be negotiated in other ways, or the Early TA value may not be negotiated.

[0744] In some embodiments, steps S7701 to S7503 may be combined with some steps in the embodiment shown in FIG7D . For example, step S7408 in FIG7D may include steps S7701 to S7702 or may be replaced by steps S7701 to S7502.

[0745] In the embodiments of the present disclosure, some or all of the steps and their optional implementations may be arbitrarily combined with some or all of the steps in other embodiments, or may be arbitrarily combined with the optional implementations of other embodiments.

[0746] Figure 7H is an interactive diagram of a communication method according to an embodiment of the present disclosure. As shown in Figure 7H, the embodiment of the present disclosure relates to a communication method, and the method includes:

[0747] Step S7801: The MN sends an SN Change Confirm message to the serving SN.

[0748] In step S7802, the terminal performs early TA acquisiton with the candidate SN.

[0749] In some embodiments, early TA acquisiton may be a process in which the terminal sends the third information in some of the above embodiments to the candidate SN, and enables the terminal to receive the TA value corresponding to one or more candidate cells determined by the candidate SN.

[0750] Step S7803: The candidate SN sends a TA information transfer message to the MN.

[0751] Step S7804: The MN sends a TA information transfer message to the serving SN.

[0752] In some embodiments, the TA information transfer message may be the second information described in some of the above embodiments.

[0753] Step S7805: The serving SN sends a Cell Switch Command to the terminal.

[0754] In some embodiments, the Cell Switch Command may be the first information described in some of the above embodiments.

[0755] In some embodiments, the process from step S7801 to step S7804 may be a process for negotiating an Early TA value, for example, it may be referred to as negotiation of an Early TA value of an SCG LTM initiated by an SN in a DC scenario.

[0756] In some embodiments, one or more steps from step S7801 to step S7804 are optional. For example, the Early TA value may be negotiated in other ways, or the Early TA value may not be negotiated.

[0757] In some embodiments, steps S7801 to S7504 may be combined with some steps in the embodiment shown in FIG. 7E . For example, step S7509 in FIG. 7E may include steps S7801 to S7804 or may be replaced by steps S7801 to S7804.

[0758] In the embodiments of the present disclosure, some or all of the steps and their optional implementations may be arbitrarily combined with some or all of the steps in other embodiments, or may be arbitrarily combined with the optional implementations of other embodiments.

[0759] The embodiments of the present disclosure further provide an apparatus for implementing any of the above methods. For example, an apparatus is provided, comprising units or modules for implementing each step performed by a terminal in any of the above methods. For another example, another apparatus is provided, comprising units or modules for implementing each step performed by a network device (e.g., an access network device, a core network function node, a core network device, etc.) in any of the above methods.

[0760] It should be understood that the division of the various units or modules in the above device is merely a division of logical functions. In actual implementation, they may be fully or partially integrated into a physical entity, or they may be physically separated. In addition, the units or modules in the device may be implemented in the form of a processor calling software: for example, the device includes a processor, the processor is connected to a memory, and the memory stores instructions. The processor calls the instructions stored in the memory to implement any of the above methods or implement the functions of the various units or modules of the above device, wherein the processor is, for example, a general-purpose processor, such as a central processing unit (CPU) or a microprocessor, and the memory is a memory within the device or a memory outside the device. Alternatively, the units or modules in the device can be implemented in the form of hardware circuits, and the functions of some or all of the units or modules can be realized by designing the hardware circuits. The above-mentioned hardware circuits can be understood as one or more processors; for example, in one implementation, the above-mentioned hardware circuit is an application-specific integrated circuit (ASIC), which realizes the functions of some or all of the above units or modules by designing the logical relationship of the components in the circuit; for example, in another implementation, the above-mentioned hardware circuit can be realized by a programmable logic device (PLD). Taking a field programmable gate array (FPGA) as an example, it can include a large number of logic gate circuits, and the connection relationship between the logic gate circuits is configured by configuring the configuration file, thereby realizing the functions of some or all of the above units or modules. All units or modules of the above devices can be realized in the form of software called by the processor, or in the form of hardware circuits, or in part by the form of software called by the processor, and the rest by hardware circuits.

[0761] In the embodiments of the present disclosure, the processor is a circuit with signal processing capabilities. In one implementation, the processor can be a circuit with instruction reading and execution capabilities, such as a central processing unit (CPU), a microprocessor, a graphics processing unit (GPU) (which can be understood as a microprocessor), or a digital signal processor (DSP). In another implementation, the processor can implement certain functions through the logical relationship of the hardware circuit. The logical relationship of the above-mentioned hardware circuit is fixed or reconfigurable. For example, the processor is a hardware circuit implemented by an application-specific integrated circuit (ASIC) or a programmable logic device (PLD), such as an FPGA. In a reconfigurable hardware circuit, the process of the processor loading a configuration document and implementing the hardware circuit configuration can be understood as the process of the processor loading instructions to implement the functions of some or all of the above units or modules. In addition, it can also be a hardware circuit designed for artificial intelligence, which can be understood as an ASIC, such as a neural network processing unit (NPU), a tensor processing unit (TPU), a deep learning processing unit (DPU), etc.

[0762] Figure 8A is a structural diagram of the first node proposed in an embodiment of the present disclosure. As shown in Figure 8A, the first node 8100 may include: at least one of a transceiver module 8101, a processing module 8102, etc. In some embodiments, the above-mentioned transceiver module 8101 is used to determine the execution of cell switching to the first cell, and send a first information to the terminal, the first information is used to instruct the terminal to execute the cell switching to the first cell, the first node is the node associated with the service cell of the terminal, and the service cell and the first cell correspond to different nodes. Optionally, the above-mentioned transceiver module is used to execute at least one of the communication steps such as sending and / or receiving executed by the first node in any of the above methods, which will not be repeated here. Optionally, the above-mentioned processing module is used to execute at least one of the other steps executed by the first node in any of the above methods, which will not be repeated here.

[0763] Figure 8B is a schematic diagram of the structure of the second node proposed in an embodiment of the present disclosure. As shown in Figure 8B, the second node 8200 may include: at least one of a transceiver module 8201, a processing module 8202, etc. In some embodiments, the transceiver module 8201 is used to send second information to the first node, and the second information includes timing advance TA related information of the first cell. The first node is a node associated with the service cell of the terminal, and the second node is a node associated with the first cell. The first cell and the service cell correspond to different nodes. Optionally, the transceiver module is used to execute at least one of the communication steps such as sending and / or receiving executed by the second node in any of the above methods, which will not be repeated here. Optionally, the processing module is used to execute at least one of the other steps executed by the second node in any of the above methods, which will not be repeated here.

[0764] Figure 8C is a structural diagram of the terminal proposed in an embodiment of the present disclosure. As shown in Figure 8C, the terminal 8300 may include: at least one of a transceiver module 8301, a processing module 8302, etc. In some embodiments, the above-mentioned transceiver module 8301 is used to receive first information sent by a first node, and the first node is a node associated with the service cell of the terminal; the processing module 8302 is used to perform cell switching to the first cell according to the first information, and the first cell and the service cell correspond to different nodes. Optionally, the above-mentioned transceiver module is used to execute at least one of the communication steps such as sending and / or receiving executed by the terminal in any of the above methods, which will not be repeated here. Optionally, the above-mentioned processing module is used to execute at least one of the other steps executed by the terminal in any of the above methods, which will not be repeated here.

[0765] In some embodiments, the transceiver module may include a transmitting module and / or a receiving module, and the transmitting module and the receiving module may be separate or integrated. Optionally, the transceiver module may be interchangeable with the transceiver.

[0766] In some embodiments, the processing module can be a single module or can include multiple submodules. Optionally, the multiple submodules respectively execute all or part of the steps required to be executed by the processing module. Optionally, the processing module can be interchangeable with the processor.

[0767] Figure 9A is a schematic diagram of the structure of a communication device 9100 proposed in an embodiment of the present disclosure. Communication device 9100 can be a network device (e.g., a first node, a second node, an access network device, a core network device, etc.), or a terminal (e.g., a user device, etc.), or a chip, chip system, or processor that supports a network device to implement any of the above methods, or a chip, chip system, or processor that supports a terminal to implement any of the above methods. Communication device 9100 can be used to implement the methods described in the above method embodiments. For details, please refer to the description of the above method embodiments.

[0768] As shown in Figure 9A, the communication device 9100 includes one or more processors 9101. The processor 9101 can be a general-purpose processor or a dedicated processor, for example, a baseband processor or a central processing unit. The baseband processor can be used to process the communication protocol and communication data, and the central processing unit can be used to control the communication device (such as a base station, a baseband chip, a terminal device, a terminal device chip, a Bluetooth device, a Bluetooth chip, a DU or a CU, etc.), execute programs, and process program data. Optionally, the communication device 9100 is used to perform any of the above methods. Optionally, one or more processors 9101 are used to call instructions to enable the communication device 9100 to perform any of the above methods.

[0769] In some embodiments, the communication device 9100 further includes one or more transceivers 9102. When the communication device 9100 includes one or more transceivers 9102, the transceiver 9102 performs at least one of the communication steps, such as sending and / or receiving, in the above-described method, and the processor 9101 performs at least one of the other steps. In an optional embodiment, the transceiver may include a receiver and / or a transmitter, and the receiver and transmitter may be separate or integrated. Optionally, the terms transceiver, transceiver unit, transceiver, transceiver circuit, interface circuit, and interface may be interchangeable, the terms transmitter, transmitting unit, transmitter, and transmitting circuit may be interchangeable, and the terms receiver, receiving unit, receiver, and receiving circuit may be interchangeable.

[0770] In some embodiments, the communication device 9100 further includes one or more memories 9103 for storing data. Alternatively, all or part of the memories 9103 may be located outside the communication device 9100. In alternative embodiments, the communication device 9100 may include one or more interface circuits 9104. Optionally, the interface circuits 9104 are connected to the memories 9103 and may be configured to receive data from the memories 9103 or other devices, or to send data to the memories 9103 or other devices. For example, the interface circuits 9104 may read data stored in the memories 9103 and send the data to the processor 9101.

[0771] The communication device 9100 described in the above embodiments may be a network device or a terminal, but the scope of the communication device 9100 described in the present disclosure is not limited thereto, and the structure of the communication device 9100 may not be limited by FIG. 9A . The communication device may be an independent device or may be part of a larger device. For example, the communication device may be: 1) an independent integrated circuit IC, or a chip, or a chip system or subsystem; (2) a collection of one or more ICs, optionally, the above IC collection may also include a storage component for storing data or programs; (3) an ASIC, such as a modem; (4) a module that can be embedded in other devices; (5) a receiver, a terminal device, an intelligent terminal device, a cellular phone, a wireless device, a handheld device, a mobile unit, an in-vehicle device, a network device, a cloud device, an artificial intelligence device, etc.; (6) others, etc.

[0772] 9B is a schematic diagram of the structure of a chip 9200 according to an embodiment of the present disclosure. If the communication device 9100 can be a chip or a chip system, please refer to the schematic diagram of the structure of the chip 9200 shown in FIG9B , but the present disclosure is not limited thereto.

[0773] The chip 9200 includes one or more processors 9201. The chip 9200 is configured to execute any of the above methods.

[0774] In some embodiments, chip 9200 further includes one or more interface circuits 9202. Terms such as interface circuit, interface, and transceiver pins may be used interchangeably. In some embodiments, chip 9200 further includes one or more memories 9203 for storing data. Alternatively, all or part of memory 9203 may be located external to chip 9200. Optionally, interface circuit 9202 is connected to memory 9203 and may be used to receive data from memory 9203 or other devices, or may be used to send data to memory 9203 or other devices. For example, interface circuit 9202 may read data stored in memory 9203 and send the data to processor 9201.

[0775] In some embodiments, the interface circuit 9202 performs at least one of the communication steps, such as sending and / or receiving, in the above-described method. For example, the interface circuit 9202 performing the communication steps, such as sending and / or receiving, in the above-described method means that the interface circuit 9202 performs data exchange between the processor 9201, the chip 9200, the memory 9203, or the transceiver device. In some embodiments, the processor 9201 performs at least one of the other steps.

[0776] The modules and / or devices described in various embodiments, such as virtual devices, physical devices, and chips, can be arbitrarily combined or separated according to circumstances. Optionally, some or all steps can also be performed collaboratively by multiple modules and / or devices, which is not limited here.

[0777] The present disclosure also proposes a storage medium having instructions stored thereon, which, when executed on the communication device 9100, causes the communication device 9100 to execute any of the above methods. Optionally, the storage medium is an electronic storage medium. Optionally, the storage medium is a computer-readable storage medium, but is not limited thereto and may also be a storage medium readable by other devices. Optionally, the storage medium may be a non-transitory storage medium, but is not limited thereto and may also be a temporary storage medium.

[0778] The present disclosure also provides a program product, which, when executed by the communication device 9100, enables the communication device 9100 to perform any of the above methods. Optionally, the program product is a computer program product.

[0779] The present disclosure also proposes a computer program, which, when executed on a computer, causes the computer to perform any one of the above methods.

Claims

1. A communication method, characterized in that, The method includes: The first node determines to perform a cell handover to a first cell and sends first information to the terminal, where the first information is used to instruct the terminal to perform the cell handover to the first cell. The first node is the node associated with the serving cell of the terminal, and the serving cell and the first cell correspond to different nodes.

2. The method according to claim 1, characterized in that, The method includes: The first node receives second information sent by a second node, where the second information includes timing advance (TA) related information of the first cell. The first information includes the TA value of the first cell, and the TA value of the first cell is determined according to the second information. The second node is the node associated with the first cell.

3. The method according to claim 2, wherein: The first node is a source base station, and the second node is a candidate base station; or The first node is a master node (MN), and the second node is a candidate secondary node (SN); or The first node is a serving SN, and the second node is a candidate SN.

4. The method according to any one of claims 2-3, characterized in that, The TA related information of the first cell includes at least one of the following corresponding to the first cell: a first cell identifier; a TA value; a preamble; a random access radio network temporary identifier (RA-RNTI); a second node identifier.

5. The method according to any one of claims 2 to 4, characterized in that The first node is a source base station and the second node is a candidate base station, or the first node is an MN and the second node is a candidate SN. The second information is determined and sent by the second node according to third information, and the third information is sent by the terminal and includes a random access (RA) preamble.

6. The method according to any one of claims 2-5, characterized in that, The first node is a serving SN and the second node is a candidate SN. The first node receiving the second information sent by the second node includes: The first node receives the second information sent by the MN, and the second information is determined and sent by the second node to the MN according to the third information, and the third information is sent by the terminal and includes an RA preamble.

7. The method according to claim 5 or 6, characterized in that, The third information is sent by the terminal using a first random access channel (RACH) resource, and the first RACH resource is used for the first cell to perform early synchronization with the terminal.

8. The method according to any one of claims 1 to 7, characterized in that The method includes: The first node sends fourth information to the second node, where the fourth information is used to instruct the second node to determine a first random access channel (RACH) resource. The second node is the node associated with the first cell, and the first RACH resource is used for the first cell to perform early synchronization with the terminal. The first node receives fifth information sent by the second node, where the fifth information is used to indicate the first RACH resource.

9. The method according to claim 8, characterized in that, The method includes: The first node sends eighth information to the terminal, where the eighth information is used to indicate the first RACH resource.

10. The method according to claim 8 or 9, wherein: The fourth information includes a first configuration list, where the first configuration list is used to indicate second RACH resources already configured by the first node, and the second RACH resources are used for at least one second cell to perform early synchronization with the terminal. The fourth information is used to instruct the second node to determine the first RACH resources based on the second RACH resources; And / or, the method includes: The first node sends sixth information to the second node, where the sixth information includes the first configuration list, and the sixth information is used to instruct the second node to update the first RACH resources based on the second RACH resources.

11. The method according to claim 8 or 9, characterized in that, The first node sending the sixth information to the second node includes: The first node determines that there is a conflict between the first RACH resources and the second RACH resources, and sends the sixth information to the second node.

12. The method according to any one of claims 9 to 11, characterized in that The method includes: The first node receives seventh information sent by the second node, where the seventh information is used to indicate the updated first RACH resources.

13. The method according to any one of claims 9-12, characterized in that, The first configuration list includes at least one of the following: The node identifier of a third node, where the third node is the node associated with the second cell; The cell identifier of the second cell; The configuration identifier corresponding to the second cell; The configuration of the RACH resources corresponding to the configuration identifier.

14. A communication method, characterized in that, The method includes: The second node sends second information to the first node, where the second information includes timing advance TA-related information of a first cell. The first node is the node associated with the serving cell of the terminal, the second node is the node associated with the first cell, and the first cell and the serving cell correspond to different nodes.

15. The method according to claim 14, wherein The first node is a source base station, and the second node is a candidate base station; or, The first node is a master node MN, and the second node is a candidate secondary node SN; or The first node is a serving secondary node SN, and the second node is a candidate SN.

16. The method according to any one of claims 14 - 15, characterized in that, The TA-related information of the first cell includes at least one of the following corresponding to the first cell: first cell identifier; TA value; preamble; RA-RNTI; second node identifier.

17. The method according to any one of claims 14 to 16, characterized in that, The first node is a source gNB and the second node is a candidate gNB, or the first node is an MN and the second node is a candidate SN, The second node sending the second information to the first node includes: The second node receives third information sent by the terminal, where the third information includes a random access RA preamble; The second node determines and sends the second information to the first node based on the third information.

18. The method according to any one of claims 14 - 17, characterized in that, The first node is a serving SN and the second node is a candidate SN, The second node sending the second information to the first node includes: The second node sends the second information to the first node through the MN. The second information is determined by the second node based on third information, and the third information is sent by the terminal and includes an RA preamble.

19. The method according to claim 17 or 18, characterized in that The third information is sent by the terminal using a first random access channel (RACH) resource, and the first RACH resource is used for the first cell to perform early synchronization with the terminal.

20. The method according to any one of claims 14-19, characterized in that, The method includes: The second node receives fourth information sent by the first node; The second node determines a first RACH resource, and the first RACH resource is used for the first cell to perform early synchronization with the terminal; The second node sends fifth information to the first node, and the fifth information is used to indicate the first RACH resource.

21. The method according to claim 20, wherein The fourth information includes a first configuration list, and the first configuration list is used to indicate second RACH resources configured by the first node. The second RACH resources are used for at least one second cell to perform early synchronization with the terminal. The fourth information is used to indicate that the second node determines the first RACH resource according to the second RACH resources; and / or, the second node determines the first RACH resource, including: the second node receives sixth information sent by the first node, and the sixth information includes the first configuration list; The third node updates the first RACH resource according to the second RACH resources.

22. The method according to claim 21, wherein The method includes: The second node sends seventh information to the first node, and the seventh information is used to indicate the updated first RACH resource.

23. The method according to any one of claims 21-22, characterized in that, The first configuration list includes at least one of the following: The node identifier of the third node, where the third node is the node associated with the second cell; The cell identifier of the second cell; The configuration identifier corresponding to the second cell; The configuration of the RACH resource corresponding to the configuration identifier.

24. A communication method, characterized in that, The method includes: The terminal receives first information sent by the first node, and the first node is the node associated with the serving cell of the terminal; The terminal performs a cell handover to the first cell according to the first information, and the first cell and the serving cell correspond to different nodes.

25. The method according to claim 24, wherein The method includes: The terminal performs a cell handover to the first cell according to the TA value of the first cell in the first information. The TA value of the first cell is determined by the first node according to second information, and the second information is sent by the second node. The second information includes TA-related information of the first cell, and the second node is the node associated with the first cell.

26. The method according to claim 25, wherein The first node is a source base station, and the second node is a candidate base station; or The first node is a master node (MN), and the second node is a candidate secondary node (SN); or The first node is a serving SN, and the second node is a candidate SN.

27. The method according to any one of claims 24-25, characterized in that, The TA-related information of the first cell includes at least one of the following corresponding to the first cell: first cell identifier; TA value; preamble; RA-RNTI; second node identifier.

28. The method according to any one of claims 23-26, characterized in that, The method includes: The terminal sends third information to the second node, where the third information is used by the second node to determine the second information, and the third information includes a random access (RA) preamble.

29. The method according to claim 27, wherein The third information is sent by the terminal using a first random access channel (RACH) resource, and the first RACH resource is used for the first cell to perform early synchronization with the terminal.

30. The method according to any one of claims 24-29, characterized in that, The method includes: The terminal receives eighth information sent by the first node, where the eighth information is used to indicate a first RACH resource, and the first RACH resource is used for the first cell to perform early synchronization with the terminal.

31. A first node, characterized in that, The first node includes: A transceiver module, configured to determine that a cell handover to the first cell is to be performed, and send first information to the terminal, where the first information is used to instruct the terminal to perform the cell handover to the first cell. The first node is a node associated with the serving cell of the terminal, and the serving cell and the first cell correspond to different nodes.

32. A second node, characterized in that, The second node includes: A transceiver module, configured to send second information from the second node to the first node, where the second information includes timing advance (TA) related information of the first cell. The first node is a node associated with the serving cell of the terminal, the second node is a node associated with the first cell, and the first cell and the serving cell correspond to different nodes.

33. A terminal, characterized in that, The terminal includes: A transceiver module, configured to receive first information sent by the first node, where the first node is a node associated with the serving cell of the terminal; A processing module, configured to perform a cell handover to the first cell according to the first information, where the first cell and the serving cell correspond to different nodes.

34. A first node, characterized in that, Comprising: One or more processors; A memory coupled to the one or more processors, where the memory includes executable instructions, and when the executable instructions are executed by the one or more processors, the first node is caused to perform the communication method according to any one of claims 1-13.

35. A second node, characterized in that, Comprising: One or more processors; A memory coupled to the one or more processors, where the memory includes executable instructions, and when the executable instructions are executed by the one or more processors, the second node is caused to perform the communication method according to any one of claims 14-23.

36. A terminal, characterized in that, Comprising: One or more processors; A memory coupled to the one or more processors, where the memory includes executable instructions, and when the executable instructions are executed by the one or more processors, the terminal is caused to perform the communication method according to any one of claims 24-30.

37. A communication system, characterized in that, Comprising a first node, a second node, and a terminal, where the first node is configured to implement the communication method according to any one of claims 1-13, the second node is configured to implement the communication method according to any one of claims 14-23, and the terminal is configured to implement the communication method according to any one of claims 24-30.

38. A storage medium storing instructions, characterized in that, When the instructions run on a communication device, the communication device is caused to perform the communication method according to any one of claims 1-13, or claims 14-23, or claims 24-30.

39. A computer program product, comprising a computer program and / or instructions, characterized in that, When the computer program and / or instructions are executed by the communication device, the communication method described in any one of claims 1 to 13, claims 14 to 23, and claims 24 to 30 is implemented.

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