Communication method and communication device

Abstract

A communication method and a communication device, the method comprising: a first communication device sends first adding request information to a second communication device, the second communication device being an auxiliary station providing services for a terminal device; receiving first addition request confirmation information of the second communication device; receiving a master station key corresponding to a candidate master cell group configuration of the first communication device after receiving the first add request acknowledgement information; after receiving the master station key, the first secondary station key is transmitted to the second communication device according to the master station key. When the service master station of the terminal equipment is switched to the first communication device and the second communication device is kept, the second communication device can timely and accurately obtain the auxiliary station key under the condition that the first communication device provides service for the terminal equipment, so that the switched terminal equipment is ensured to still use a DC architecture, and the user experience is improved. High-speed data transmission is maintained, and the user experience is ensured.

Description

Technical Field

[0001] This application relates to the field of wireless communication, and more specifically, to a communication method and a communication device. Background Technology

[0002] In mobile communication systems, the movement of a terminal causes changes in the communication link between the terminal and the access network equipment, potentially leading to cell handover or access network equipment handover. When a terminal switches from a source access network equipment to a target access network equipment, a key update is required.

[0003] In a dual-connection (DC) network architecture, a terminal device can connect to two network devices, referred to as the master node (MN) and the secondary node (SN). The MN can also be called the primary node or main station, and the SN can also be called the secondary node or secondary station. In scenarios where the MN undergoes a switchover of its access network equipment while the SN does not, the master node key between the MN and the terminal device is updated. Since the secondary station key is determined based on the master node key, it must also be updated.

[0004] In subsequent handover scenarios, assuming that MN has been switched but SN has not, how to accurately and timely update the auxiliary station key is currently a hot research topic. Summary of the Invention

[0005] This application provides a communication method that, in a subsequent switching scenario, involves a switch of the primary service station while the secondary station remains unchanged, so that the secondary station can obtain the updated secondary station key in a timely manner, ensuring data transmission to the terminal device and improving the user experience.

[0006] Firstly, a communication method is provided, which can be executed by a first communication device, or by a component of the first communication device (such as a chip or circuit), without limitation thereof. The method will now be described using a first communication device as an example.

[0007] The method may include: sending a first add request information to a second communication device; receiving a first add request confirmation information from the second communication device; after receiving the first add request confirmation information, receiving a master station key corresponding to the configuration of a candidate cell group of the first communication device; and sending a first auxiliary station key to the second communication device according to the master station key, wherein the first communication device is the target master station for terminal device handover, the second communication device is an auxiliary station providing services to the terminal device, and the candidate cell group includes a candidate master cell group.

[0008] Optionally, the candidate cell group may also include a candidate auxiliary cell group.

[0009] It should be understood that the candidate primary cell group includes one primary cell. Optionally, the candidate primary cell group may also include one or more secondary cells.

[0010] According to the method provided in this application, after the first communication device receives the master station key, it sends a first auxiliary station key to the second communication device based on the master station key, wherein the first auxiliary station key is determined based on the master station key. When the service master station of the terminal device switches to the first communication device, and the second communication device remains active, the second communication device can obtain the auxiliary station key in a timely and accurate manner when the first communication device provides services to the terminal device. This ensures that the terminal device continues to use the DC architecture after the switch, maintaining high-speed data transmission and guaranteeing user experience.

[0011] In conjunction with the first aspect, in some possible implementations, after receiving the first add request confirmation information, the method further includes: receiving first information, the first information being used to instruct the service master station of the terminal device to switch to the first communication device.

[0012] Optionally, the first information can also be used to indicate the candidate configuration identifier corresponding to the target primary cell group that the terminal device will switch to. The target primary cell group belongs to the candidate primary cell group of the first communication device.

[0013] In conjunction with the first aspect, in some possible implementations, the first information includes the master station key.

[0014] It should be understood that the master station key received by the first communication device can be transmitted through the first information, which is information used to instruct the terminal device to switch its service master station to the first communication device.

[0015] In conjunction with the first aspect, in some possible implementations, sending the first auxiliary station key to the second communication device based on the master station key includes: sending the first auxiliary station key to the second communication device based on receiving the master station key.

[0016] It should be understood that the first communication device sending the first auxiliary station key to the second communication device can be understood as the first communication device determining the first auxiliary station key based on the master station key and sending the first auxiliary station key to the second communication device when the first communication device receives the master station key.

[0017] In conjunction with the first aspect, in some possible implementations, the first add request information includes one or more of the following: information indicating that the first communication device is a candidate communication device for terminal device handover, information indicating that the first communication device is a candidate communication device for subsequent handover of the terminal device, or information indicating that the first communication device is a candidate communication device for handover of the terminal device across base stations or across central units.

[0018] In conjunction with the first aspect, in some possible implementations, sending the first auxiliary station key to the second communication device based on the master station key includes: determining the first auxiliary station key based on the master station key and a first count value; sending the first auxiliary station key to the second communication device, wherein the first count value corresponds to the target primary cell group that the terminal device is about to access, and the target primary cell group belongs to the candidate primary cell group of the first communication device.

[0019] It should be understood that the counter value in this application may be referred to as sk-counter or sn-counter.

[0020] It should be understood that the first communication device in this application corresponds to at least one candidate primary cell group, which includes one primary cell. The candidate primary cell group may also include one or more secondary cells. The candidate primary cell group includes a target primary cell.

[0021] In conjunction with the first aspect, in some possible implementations, sending the first auxiliary station key to the second communication device based on the master station key includes: determining the first auxiliary station key based on the master station key and the first unused count value among a plurality of count values; sending the first auxiliary station key to the second communication device, wherein the first count value corresponds to the target primary cell group that the terminal device is about to access, and the target primary cell group belongs to the candidate primary cell group of the first communication device.

[0022] It should be understood that the terminal device is about to access one of the candidate primary cell groups in at least one candidate primary cell group of the first communication device, and this candidate primary cell group can be referred to as the target primary cell group. The target primary cell group is configured with multiple corresponding count values. When determining the first secondary station key, the first communication device uses the first unused count value among the multiple count values ​​and the primary station key to determine the first secondary station key.

[0023] It should also be understood that the target primary cell group belongs to the candidate primary cell group of the target primary station for terminal device handover, that is, the target primary cell includes one primary cell. Assuming that the target primary cell also includes one or more secondary cells, when the terminal device accesses the target primary cell, the terminal device accesses all cells included in the target primary cell group.

[0024] In conjunction with the first aspect, in some possible implementations, before receiving the master station key corresponding to the candidate master cell group configuration of the first communication device, the method further includes: sending handover request confirmation information to a third communication device, the handover request confirmation information including configuration information of the candidate master cell group corresponding to the first communication device and the plurality of count values, wherein the third communication device is a source master station providing services to the terminal device.

[0025] In conjunction with the first aspect, in some possible implementations, sending the first auxiliary station key to the second communication device includes: sending auxiliary station reconfiguration completion information to the second communication device, wherein the auxiliary station reconfiguration completion information includes the first auxiliary station key.

[0026] It should be understood that when the first communication device sends the first auxiliary station key to the second communication device, the first auxiliary station key can be carried in the auxiliary station reconfiguration completion information of the first communication device, thereby saving the signaling overhead of the first communication device.

[0027] In conjunction with the first aspect, in some possible implementations, the method further includes: sending second information to the second communication device, the second information including the identifier of the target primary cell group and / or the candidate configuration identifier corresponding to the target primary cell group, the identifier of the target primary cell group and the candidate configuration identifier corresponding to the target primary cell corresponding to the first auxiliary station key, the target primary cell group being the primary cell group that the terminal device is about to access, and the target primary cell group belonging to the candidate primary cell group of the first communication device.

[0028] It should be understood that the first communication device can also send second information to the second communication device. The identifier of the target primary cell group and / or the candidate configuration identifier corresponding to the target primary cell group in the second information can enable the second communication device to select the first auxiliary station key corresponding to the configuration of the target primary cell group from multiple received auxiliary station keys (e.g., first auxiliary station key, second auxiliary station key, third auxiliary station key, etc.). This is used for communication between the second communication device and the terminal device when the first communication device provides services to the terminal device, i.e., when the terminal device accesses the target primary cell group, thereby ensuring normal data transmission of the terminal device.

[0029] It should also be understood that the first auxiliary station key in this application can also be understood as being used for security processing during the communication process between the second communication device and the terminal equipment.

[0030] Secondly, a communication method is provided, which can be executed by a second communication device, or by a component of the second communication device (such as a chip or circuit), and this application does not limit this. The method is described below using a second communication device as an example.

[0031] The method includes: receiving at least one add request information for at least one candidate communication device; sending at least one add request confirmation information to at least one candidate communication device; and after sending the at least one add request confirmation information, receiving at least one secondary station key, the at least one secondary station key corresponding to the configuration of at least one candidate cell group of at least one candidate communication device, the at least one candidate cell group including at least one candidate cell group, wherein at least one candidate communication device includes a first communication device, the first communication device being a target primary station for terminal device handover, the at least one secondary station key including a first secondary station key, the first secondary station key being used for communication between a second communication device and the terminal device when the terminal device accesses the target primary cell group, the target primary cell group belonging to the candidate primary cell group of the first communication device, and the second communication device being a secondary station providing services to the terminal device.

[0032] It should be understood that the at least one add request information corresponds to the candidate primary cell group configuration of the at least one candidate communication device. Specifically, the configuration of the candidate primary cell group of one of the at least one candidate communication device corresponds to the at least one add request information.

[0033] According to the method provided in this application, after the second communication device sends at least one add request confirmation message, the second communication device receives at least one auxiliary station key. The at least one auxiliary station key includes a first auxiliary station key corresponding to the configuration of the target primary cell group. When the serving primary station of the terminal device switches to the first communication device, and the second communication device remains active, the second communication device can obtain the first auxiliary station key corresponding to the target primary cell group in a timely and accurate manner, thereby ensuring that the terminal device still uses the DC architecture after the switchover, maintaining high-speed data transmission and guaranteeing user experience.

[0034] Furthermore, the at least one secondary station key received by the second communication device can be at least one secondary station key corresponding to the configuration of at least one candidate primary cell group of at least one candidate communication device, determined by at least one candidate communication device upon receiving the primary station key, and then sent to the second communication device. This ensures that the second communication device has obtained the secondary station key before the terminal device's serving primary station handover, thereby guaranteeing that communication between the terminal device and the secondary station can be restored as quickly as possible during subsequent primary station handover, thus ensuring a better user experience.

[0035] In conjunction with the second aspect, in some possible implementations, the at least one add request information includes first add request information, which includes one or more of the following: information indicating that the first communication device is a candidate communication device for terminal device handover, information indicating that the first communication device is a candidate communication device for subsequent handover of the terminal device, or information indicating that the first communication device is a candidate communication device for terminal device handover across base stations or across central units. If the first add request information also includes a second auxiliary station key, the method further includes: ignoring the second auxiliary station key.

[0036] It should be understood that, taking the first addition request information in at least one addition request information as an example, if the first addition request information includes one or more of the following: information indicating that the first communication device is a candidate communication device for terminal device handover, information indicating that the first communication device is a candidate communication device for subsequent handover of terminal device, or information indicating that the first communication device is a candidate communication device for terminal device handover across base stations or across central units, the first addition request information also includes a second auxiliary station key, then the second communication device ignores the second auxiliary station key.

[0037] It should also be understood that if the second add request information in at least one add request information does not include any one or more of the above indication information, and the second add request information includes a second auxiliary station key, then the second communication device may store the second auxiliary station key locally for subsequent communication with the terminal device.

[0038] In conjunction with the second aspect, in some possible implementations, when receiving multiple auxiliary station keys from multiple candidate communication devices, the method further includes: receiving second information from the first communication device, the second information including an identifier of the target primary cell group and / or a candidate configuration identifier corresponding to the target primary cell group, the identifier of the target primary cell group and / or the candidate configuration identifier corresponding to the target primary cell corresponding to the first auxiliary station key; selecting the first auxiliary station key from the multiple auxiliary station keys according to the second information; and communicating with the terminal device according to the first auxiliary station key, wherein the target primary cell group is the primary cell group that the terminal device will access.

[0039] It should be understood that the multiple auxiliary station keys received by the second communication device are associated with the identifiers of multiple candidate primary cell groups and / or the candidate configuration identifiers of multiple candidate primary cell groups. These multiple candidate primary cell groups include the target primary cell group.

[0040] It should be understood that, assuming the second communication device receives multiple auxiliary station keys, the second communication device can select an auxiliary station key (e.g., the first auxiliary station key) from the multiple auxiliary station keys that corresponds to the configuration of the target primary cell group, based on the second information of the first communication device.

[0041] In conjunction with the second aspect, in some possible implementations, when receiving multiple secondary station keys from multiple candidate communication devices, the method further includes: receiving third information from the terminal device, the third information including the identifier of the target primary cell group and / or the candidate configuration identifier corresponding to the target primary cell group, the third information being information transmitted during the random access process of the terminal device, the identifier of the target primary cell group and / or the candidate configuration identifier corresponding to the target primary cell corresponding to the first secondary station key; selecting the first secondary station key from the multiple secondary station keys according to the third information; and communicating with the terminal device according to the first secondary station key, wherein the target primary cell group is the primary cell group that the terminal device will access.

[0042] It should be understood that, assuming the second communication device receives multiple auxiliary station keys, the second communication device can select an auxiliary station key (e.g., the first auxiliary station key) from the multiple auxiliary station keys that corresponds to the configuration of the target primary cell group based on the third information of the terminal device.

[0043] In conjunction with the second aspect, in some possible implementations, the first add request confirmation information in the at least one add request confirmation information includes a first identifier and / or a first random access resource, the first identifier and / or the first random access resource corresponding to the target cell group configuration.

[0044] It should be understood that the random access resources in this application refer to the random access resources of the secondary cell group corresponding to the target primary cell group.

[0045] In conjunction with the second aspect, in some possible implementations, after receiving multiple secondary station keys of the multiple candidate communication devices, the method further includes: during the random access process of the terminal device, receiving a first identifier from the terminal device, selecting a first secondary station key corresponding to the configuration of the target primary cell group from the multiple secondary station keys based on the first identifier, and / or selecting the first secondary station key corresponding to the configuration of the target primary cell group from the multiple secondary station keys based on the random access resources used by the terminal device.

[0046] In conjunction with the second aspect, in some possible implementations, the random access resource includes a random access preamble and / or a random access timing indication.

[0047] In conjunction with the second aspect, in some possible implementations, after selecting the first auxiliary station key from the plurality of auxiliary station keys, the method further includes: deleting other auxiliary station keys from the plurality of auxiliary station keys besides the first auxiliary station key.

[0048] Thirdly, a communication method is provided, which can be executed by a third communication device, or by a component of the third communication device (e.g., a chip or circuit), without limitation herein. Optionally, the third communication device can be a source master station providing services to terminal devices. The method is described below using a third communication device as an example.

[0049] The method includes: receiving at least one handover request confirmation message from at least one candidate communication device, the at least one candidate communication device including the first communication device, wherein the first handover request confirmation message in the at least one handover request confirmation message includes configuration information of a candidate cell group of the first communication device and at least one count value, the at least one count value corresponding to the configuration of the candidate cell group of the first communication device, the candidate cell group including a candidate primary cell group.

[0050] After receiving the at least one handover request confirmation information, the terminal device is sent Radio Resource Control (RRC) reconfiguration information.

[0051] After sending the RRC reconfiguration information to the terminal device, a fourth piece of information is sent to the terminal device. This fourth piece of information includes at least one next hop chaining count (NCC). The at least one NCC corresponds to the configuration of a candidate cell group for at least one candidate communication device. The first NCC among the at least one NCCs is used to determine the master station key corresponding to the configuration of the candidate cell group for the first communication device.

[0052] The first communication device is the target master station for the terminal device to switch to.

[0053] It should be understood that the third aspect corresponds to the first and second aspects mentioned above, and for specific details and technical effects, please refer to the descriptions of the first and second aspects mentioned above.

[0054] In conjunction with the third aspect, in some possible implementations, the fourth information also includes at least one count value corresponding to the configuration of the candidate cell group for each of the at least one candidate communication device.

[0055] It should be understood that the third communication device sends fourth information to the terminal device, which includes at least one count value, thereby ensuring that the terminal device can obtain the auxiliary station key between the terminal device and the auxiliary station in a timely manner when the service master station of the terminal device sends a switch, thus ensuring data transmission between the terminal device and the auxiliary station.

[0056] In conjunction with the third aspect, in some possible implementations, after sending the fourth information, the method further includes:

[0057] Send a first message to the first communication device, the first message being used to instruct the service master station of the terminal device to switch to the first communication device.

[0058] In conjunction with the third aspect, in some possible implementations, the first information includes the master station key.

[0059] In conjunction with the third aspect, in some possible implementations, the method further includes:

[0060] At least one master station key is sent to the at least one candidate communication device, the at least one master station key corresponding to at least one candidate primary cell group configuration of the at least one candidate communication device, and the at least one master station key includes the master station key.

[0061] Fourthly, a communication method is provided, which can be executed by a terminal device, or by a component of the terminal device (such as a chip or circuit), and this application does not limit this. The method is described below using a terminal device as an example.

[0062] The method includes: receiving Radio Resource Control (RRC) reconfiguration information from a third communication device;

[0063] After receiving the RRC reconfiguration information, fourth information is received from the third communication device. This fourth information includes at least one next-hop chain calculation NCC, which corresponds to the configuration of a candidate cell group for at least one candidate communication device. The first NCC in the at least one NCC is used to determine the master station key corresponding to the configuration of the candidate cell group for the first communication device. The at least one candidate communication device includes the first communication device, and the candidate cell group includes a candidate master cell group.

[0064] Wherein, the first communication device is the target master station for terminal device handover, the third communication device is the source master station providing services to the terminal device, and the RRC reconfiguration information includes the configuration information of the candidate cell group of each candidate communication device and at least one count value corresponding to the configuration information of the candidate cell group.

[0065] It should be understood that the configuration information of the candidate cell group includes the configuration information of the candidate primary cell group.

[0066] It should also be understood that the fourth aspect corresponds to the first to third aspects mentioned above, and for details, please refer to the descriptions of the first to third aspects mentioned above.

[0067] In conjunction with the fourth aspect, in some possible implementations, the fourth information further includes at least one count value corresponding to the candidate cell group configuration of each of the at least one candidate communication device.

[0068] In conjunction with the fourth aspect, in some possible implementations, the method further includes: determining a first auxiliary station key based on the master station key and a first count value among the at least one count value, the first count value corresponding to the configuration of the candidate master cell group of the first communication device; and communicating with a second communication device based on the first auxiliary station key, wherein the second communication device is an auxiliary station providing services to the terminal device.

[0069] In conjunction with the fourth aspect, in some possible implementations, where the candidate primary cell group of the first communication device is configured with multiple count values, the first count value is the first unused count value among the multiple count values.

[0070] In conjunction with the fourth aspect, in some possible implementations, before communicating with the second communication device according to the first auxiliary station key, the method further includes: receiving handover command information from the third communication device, the handover command being used to indicate the identifier of the target primary cell group to which the terminal device is to hand over.

[0071] In conjunction with the fourth aspect, in some possible implementations, the RRC reconfiguration information further includes at least one second identifier and / or at least one random access resource, the at least one second identifier and / or the at least one random access resource corresponding to the configuration of at least one candidate cell group for each candidate communication device.

[0072] It should be understood that the at least one second identifier is an identifier used by the terminal device when configuring the candidate cell group corresponding to the second identifier. For example, the identifier included in the at least one second identifier may be a cell-radio network temporary identifier (C-RNTI). Each second identifier corresponds to a candidate cell group; for example, the first identifier in the at least one second identifier corresponds to a target cell group that belongs to the candidate cell group of the first communication device.

[0073] In conjunction with the fourth aspect, in some possible implementations, during the process of the terminal device initiating random access to the second communication device, the method further includes:

[0074] Send a first identifier from the at least one second identifier to the second communication device, the first identifier being used to determine a first auxiliary station key from a plurality of auxiliary station keys; and / or,

[0075] Random access is initiated using a first random access resource from the at least one random access resource, wherein the first random access resource is used to determine the first secondary site key from the plurality of secondary site keys.

[0076] The plurality of auxiliary station keys correspond to the configuration of the candidate primary cell group for each candidate communication device, and the plurality of candidate communication devices include the first communication device. The first auxiliary station key corresponds to the configuration of the candidate primary cell group for the first communication device.

[0077] It should be understood that the auxiliary station key corresponds to the configuration of the candidate primary cell group. This can be understood as the terminal device communicating with the auxiliary station using the auxiliary station key corresponding to the configuration of the candidate primary cell group when accessing the candidate primary cell.

[0078] Fifthly, a communication apparatus is provided for performing the method provided in the first aspect. Specifically, the communication apparatus may include units and / or modules for performing the method provided in any of the above implementations of the first aspect, such as a processing unit and an acquisition unit.

[0079] In one implementation, the transceiver unit can be a transceiver or an input / output interface; the processing unit can be at least one processor. Optionally, the transceiver can be a transceiver circuit. Optionally, the input / output interface can be an input / output circuit.

[0080] In another implementation, the transceiver unit can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip, chip system, or circuit; the processing unit can be at least one processor, processing circuit, or logic circuit.

[0081] In a sixth aspect, a communication apparatus is provided for performing the method provided in the second aspect. Specifically, the communication apparatus may include units and / or modules for performing the method provided in the second aspect, such as a processing unit and an acquisition unit.

[0082] In one implementation, the transceiver unit can be a transceiver or an input / output interface; the processing unit can be at least one processor. Optionally, the transceiver can be a transceiver circuit. Optionally, the input / output interface can be an input / output circuit.

[0083] In another implementation, the transceiver unit can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip, chip system, or circuit; the processing unit can be at least one processor, processing circuit, or logic circuit.

[0084] In a seventh aspect, a communication apparatus is provided for performing the method provided in the third aspect. Specifically, the communication apparatus may include units and / or modules for performing the method provided in the third aspect, such as a processing unit and an acquisition unit.

[0085] In one implementation, the transceiver unit can be a transceiver or an input / output interface; the processing unit can be at least one processor. Optionally, the transceiver can be a transceiver circuit. Optionally, the input / output interface can be an input / output circuit.

[0086] In another implementation, the transceiver unit can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip, chip system, or circuit; the processing unit can be at least one processor, processing circuit, or logic circuit.

[0087] Eighthly, a communication apparatus is provided for performing the method provided in the fourth aspect. Specifically, the communication apparatus may include units and / or modules for performing the method provided in the fourth aspect, such as a processing unit and an acquisition unit.

[0088] In one implementation, the transceiver unit can be a transceiver or an input / output interface; the processing unit can be at least one processor. Optionally, the transceiver can be a transceiver circuit. Optionally, the input / output interface can be an input / output circuit.

[0089] In another implementation, the transceiver unit can be an input / output interface, interface circuit, output circuit, input circuit, pin, or related circuit on the chip, chip system, or circuit; the processing unit can be at least one processor, processing circuit, or logic circuit.

[0090] Ninthly, this application provides a processor for executing the method provided by any of the implementations of the first to fourth aspects described above.

[0091] Unless otherwise specified, or if it does not contradict its actual function or internal logic in the relevant description, the transmission and acquisition / reception operations involved in the processor can be understood as processor output and reception, input and other operations, or as transmission and reception operations performed by radio frequency circuits and antennas. This application does not limit them in this regard.

[0092] In a tenth aspect, a computer-readable storage medium is provided that stores program code for execution by a device, the program code including a method for performing any of the implementations of the first to fourth aspects described above.

[0093] Eleventhly, a computer program product containing instructions is provided, which, when run on a computer, causes the computer to execute the method provided by any one of the implementations of the first to fourth aspects described above.

[0094] In a twelfth aspect, a chip is provided, the chip including a processor and a communication interface, wherein the processor reads instructions stored in a memory through the communication interface and executes the method provided by any one of the implementations of the first to fourth aspects described above.

[0095] Optionally, as one implementation, the chip also includes a memory storing computer programs or instructions, and a processor for executing the computer programs or instructions stored in the memory. When the computer programs or instructions are executed, the processor is used to execute the method provided by any of the first to fourth aspects described above.

[0096] In a thirteenth aspect, a communication system is provided, including the first communication device, the second communication device, and the third communication device described above. Attached Figure Description

[0097] Figure 1 This is a schematic diagram of the network architecture applicable to the embodiments of this application.

[0098] Figure 2 This is a schematic diagram of a dual-connection network architecture applicable to the embodiments of this application.

[0099] Figure 3 This is a schematic flowchart of a communication method provided in an embodiment of this application.

[0100] Figure 4 This is a schematic flowchart illustrating another communication method provided in an embodiment of this application.

[0101] Figure 5 This is a schematic flowchart illustrating another communication method provided in an embodiment of this application.

[0102] Figure 6 This is a schematic flowchart illustrating another communication method provided in an embodiment of this application.

[0103] Figure 7 This is a schematic flowchart illustrating another communication method provided in an embodiment of this application.

[0104] Figure 8This is a schematic diagram of a communication device provided in an embodiment of this application.

[0105] Figure 9 This is a schematic diagram of another communication device provided in an embodiment of this application.

[0106] Figure 10 This is a schematic diagram of a chip system provided in an embodiment of this application. Detailed Implementation

[0107] To facilitate understanding of the embodiments of this application, the following points will be explained first.

[0108] First, in this application, "for indicating" can include both direct and indirect indication. When describing an indication message as indicating A, it can include whether the indication message directly indicates A or indirectly indicates A, but does not necessarily mean that the indication message carries A.

[0109] The information indicated by the instruction is called the information to be instructed. In the specific implementation process, there are many ways to indicate the information to be instructed, such as, but not limited to, directly indicating the information to be instructed, such as the information to be instructed itself or its index. It can also be indirectly indicated by indicating other information, where there is a relationship between the other information and the information to be instructed. It can also indicate only a part of the information to be indicated, while the other parts are known or pre-agreed upon. For example, the instruction of specific information can be achieved by using a pre-agreed (e.g., protocol-defined) arrangement of various pieces of information, thereby reducing instruction overhead to some extent. At the same time, common parts of various pieces of information can be identified and indicated uniformly to reduce the instruction overhead caused by individually indicating the same information.

[0110] Second, in this application, "at least one" refers to one or more, and "more than one" refers to two or more. Furthermore, in the embodiments of this application, "first," "second," and various numerical designations (e.g., "#1," "#2," etc.) are merely for descriptive convenience and are not intended to limit the scope of the embodiments of this application. The sequence numbers of the processes below do not imply an order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. It should be understood that the objects described in this way can be interchanged where appropriate to describe solutions other than those in the embodiments of this application. Moreover, in the embodiments of this application, terms such as "S210" are merely identifiers for descriptive convenience and do not limit the order of execution steps.

[0111] Third, in the embodiments of this application, the words "exemplary" or "for example" are used to indicate that they are examples, illustrations, or descriptions. Any embodiment or design that is described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design options. Specifically, the use of the words "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0112] Fourth, the term "storage" in the embodiments of this application can refer to storage in one or more memories. These memories can be separate installations or integrated into an encoder, decoder, processor, or communication device. Alternatively, some memories can be separately installed, while others are integrated into the decoder, processor, or communication device. The type of memory can be any form of storage medium, and this application does not limit this.

[0113] Fifth, in the implementation of this application, "protocol" may refer to standard protocols in the field of communications, such as the NR protocol and related protocols applied in future communication systems, and this application does not limit it.

[0114] Sixth, in the embodiments of this application, the terms "of", "corresponding (relevant)", "corresponding", and "associate" can sometimes be used interchangeably. It should be noted that when their differences are not emphasized, their intended meanings are consistent.

[0115] Seventh, in the embodiments of this application, "under the circumstances", "when", and "if" can sometimes be used interchangeably. It should be noted that when the distinction is not emphasized, their intended meanings are consistent.

[0116] Eighth, the term "and / or" in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0117] The technical solutions in this application will now be described with reference to the accompanying drawings.

[0118] The communication method provided in this application can be applied to various communication systems, such as the Internet of Things (IoT), narrowband Internet of Things (NB-IoT), long-term evolution (LTE), 5th generation (5G) communication systems, hybrid LTE and 5G architectures, 5G new radio (NR) systems, future communication networks, or new communication systems emerging in future communication development. The communication system described in this application can also be a machine-to-machine (M2M) network or other networks.

[0119] Figure 1 A schematic diagram of a communication system applying an embodiment of this application is shown. In a 5G system, a 5G access point consists of a base station node and a next-generation radio access network (NG-RAN). The NG-RAN node may be a 5G generation node (gNB) or an LTE evolved NodeB (ng-eNB). The gNB uses the NR user plane and control plane protocol stack, while the ng-eNB uses the evolved universal terrestrial radio access (E-UTRA) user plane and control plane protocol stack, except for the Service Data Adaptation Protocol (SDAP) layer.

[0120] gNBs interconnect with each other, ng-eNBs with each other, and gNBs with ng-eNBs via the Xn interface. gNBs and ng-eNBs connect to 5G core network (5GC) equipment via the NG interface. For example, the control plane connects to core network equipment (e.g., the access and mobility management function, AMF) via the NG-C interface, and the user plane connects to core network equipment (e.g., the user plane function, UPF) via the NG-U interface.

[0121] It should be understood that Figure 1 This is merely an example and does not constitute any limitation on the scope of protection of this application. Figure 1The scenario shown may also include other devices, such as terminal devices and servers. For example, 5GC also includes other functional network elements besides AMF and APF.

[0122] In this application, "terminal equipment" can refer to an access terminal, user unit, user station, mobile station, mobile station, relay station, remote station, remote terminal, mobile device, user terminal, user equipment (UE), terminal, wireless communication device, user agent, or user device. Terminal equipment can also be a cellular phone, cordless phone, session initiation protocol (SIP) phone, wireless local loop (WLL) station, personal digital assistant (PDA), handheld device with wireless communication capabilities, computing device or other processing device connected to a wireless modem, vehicle-mounted device, wearable device, terminal equipment in a 5G network, or terminal equipment in a future public land mobile network (PLMN), etc. This application does not limit the scope of the application.

[0123] As an example and not a limitation, in this application embodiment, wearable devices can also be called wearable smart devices. This is a general term for devices that utilize wearable technology to intelligently design and develop everyday wearables, such as glasses, gloves, watches, clothing, and shoes. Wearable devices are portable devices that are worn directly on the body or integrated into the user's clothing or accessories. Wearable devices are not merely hardware devices; they achieve powerful functions through software support, data interaction, and cloud interaction. Broadly defined, wearable smart devices include those that are feature-rich, large in size, and can achieve complete or partial functionality without relying on a smartphone, such as smartwatches or smart glasses, as well as those that focus on a specific application function and require use with other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0124] Furthermore, in this embodiment, the terminal device can also be a terminal device in an IoT system. Its main technical feature is connecting objects to the network via communication technology, thereby realizing an intelligent network for human-machine interconnection and object-to-object interconnection. In this embodiment, IoT technology can achieve massive connectivity, deep coverage, and low terminal power consumption through technologies such as narrowband (NB).

[0125] For example, the terminal device can be a VR terminal, AR terminal, or MR terminal, etc., in XR scenarios; or, for example, a terminal device can be a wireless terminal in industrial control, self-driving, remote medical, smart grid, transportation safety, smart city, or smart home. Here, "terminal device" refers to a 3GPP terminal. This application does not limit the type or category of the terminal device. For ease of explanation, this application will subsequently use "UE" to refer to the terminal device as an example.

[0126] The base station in this application embodiment can be any device with wireless transceiver function used for communicating with terminal devices. This equipment includes, but is not limited to: evolved Node B (eNB), radio network controller (RNC), Node B (NB), base station controller (BSC), base transceiver station (BTS), home-evolved Node B (HeNB, or home Node B (HNB), baseband unit (BBU), access point (AP), wireless relay node, wireless backhaul node, transmission point (TP), or transmission and reception point (TRP) in a wireless fidelity (WIFI) system. It can also be a gNB in ​​a 5G system, such as NR, or a transmission point (TRP or TP), one or a group of antenna panels (including multiple antenna panels) of a base station in a 5G system, or a network node constituting a gNB or transmission point, such as a baseband unit (BBU) or a distributed unit (DMU). Units (DUs), etc., can also be used for devices that communicate with terminal devices in future communication networks, such as gNBs in future communication networks.

[0127] In some deployments, a gNB may include a centralized unit (CU) and a distribution unit (DU). The gNB may also include an active antenna unit (AAU). The CU implements some of the gNB's functions, and the DU implements others. For example, the CU handles non-real-time protocols and services, implementing radio resource control (RRC) and packet data convergence protocol (PDCP) layer functions. The DU handles physical layer protocols and real-time services, implementing radio link control (RLC), media access control (MAC), and physical (PHY) layer functions. The AAU implements some physical layer processing functions, radio frequency processing, and active antenna-related functions. Since RRC layer information ultimately becomes PHY layer information, or is derived from PHY layer information, in this architecture, higher-layer signaling, such as RRC layer signaling, can be considered to be sent by the DU, or by the DU+AAU. It is understood that access network equipment can be devices including one or more of the following: CU nodes, DU nodes, and AAU nodes. In addition, the CU can be classified as a network device in the radio access network (RAN) or as a network device in the core network (CN), and this application does not limit this.

[0128] In different systems, CU (or CU-CP and CU-UP), DU, or RU may have different names, but those skilled in the art will understand their meaning. For example, a radio access network can also be an open radio access network (O-RAN) architecture. In an ORAN system, CU can also be called O-CU (open CU), DU can also be called O-DU, CU-CP can also be called O-CU-CP, CU-UP can also be called O-CU-UP, and RU can also be called O-RU. Any of the units among CU (or CU-CP, CU-UP), DU, and RU in this application can be implemented through software modules, hardware modules, or a combination of software modules and hardware modules.

[0129] The core network equipment portion in this application embodiment may include, but is not limited to, the following NFs: UPF, network exposure function (NEF), network function repository function (NRF), policy control function (PCF), unified data management (UDM), unified data repository function (UDR), network data analytics function (NWDAF), authentication server function (AUSF), AMF, session management function (SMF), and network slice selection function (NSSF). Among these, AMF, SMF, UPF, NEF, AUSF, NRF, PCF, NSSF, and UDM can be understood as network elements in the core network used to implement different functions, for example, they can be combined into network slices as needed. These core network elements can be independent devices or integrated into the same device to implement different functions; this application does not limit the specific form of the above network elements.

[0130] It should be understood that the above naming is defined solely for the purpose of distinguishing different functions and should not constitute any limitation on this application. This application does not preclude the possibility of using other naming conventions in 5G networks and other future networks. For example, in future communication networks, some or all of the above-mentioned network elements may use the terminology from 5G, or they may use other names, etc.

[0131] It should be understood that Figure 1 This explanation uses communication between access network equipment and terminal equipment, and between access network equipment and core network equipment, as examples to briefly illustrate one communication scenario in which this application can be applied, and does not limit other scenarios in which this application can be applied. It should also be understood that... Figure 1 This is a simplified illustration for ease of understanding only. The communication system may also include other network devices or other terminal devices. Figure 1 It was not drawn in the middle.

[0132] To facilitate understanding of the embodiments of this application, some basic concepts involved in this application will be briefly explained.

[0133] To facilitate understanding of the embodiments of this application, some basic concepts involved in this application will be briefly explained.

[0134] 1. Dual connection (DC)

[0135] Figure 2 A schematic diagram of a dual-connectivity network architecture is shown. In the DC network architecture, user equipment (UE) can simultaneously connect to two access network devices, namely MN and SN. Taking the example that both MN and SN are new radio (NR) base stations, i.e., 5th generation (5G) communication system base stations, the DC network architecture is as follows. Figure 2 As shown, where, Figure 2 (a) in the diagram is a schematic diagram of the control plane architecture. Figure 2 (b) in the diagram is a schematic of the user plane architecture.

[0136] The interface between MN and SN is the Xn interface, and there is at least a control plane connection between MN and SN, i.e. Figure 2 In the diagram (a), Xn-C is shown, where C represents the control plane. A user plane connection can also exist between MN and SN, i.e. Figure 2 In the diagram (b), Xn-U is shown, where U represents the user plane; there is an NG interface between the MN and the core network equipment, and there is at least a control plane connection between the MN and the core network equipment, i.e. Figure 2 As shown in (a), the MN can have an NG-C connection with the access and mobility management function (AMF), and the MN can also have a user plane connection with the core network equipment. Figure 2 The NG-U connection between the MN and the user plane function (UPF) is shown in (b); a user plane connection can exist between the SN and the core network equipment, i.e. Figure 2 The NG-U connection between the SN and UPF is shown in (b) in the figure.

[0137] 2. Master node key / Master key (MN key)

[0138] The master key refers to the key used for communication between the UE and the MN. This master key can be denoted as k_gNB. Specifically, the UE and MN can further derive the key k_UP for user plane data security processing and the key k_RRC for control plane signaling security processing using k_gNB. The packet data convergence protocol (PDCP) layer between the UE and MN uses k_UP and k_RRC to perform security processing on user plane data and control plane signaling, respectively. For example, security processing may include operations such as integrity protection and encryption.

[0139] It should be understood that some bearers can be configured to use PDCP of the MN and radio link control (RLC) of the SN, such as the MN-terminated SCG bearer that terminates at the primary station, where SCG stands for secondary cell group. These bearers also use a master key for security processing. That is, if the PDCP layer is at the MN, then a master key is used.

[0140] 3. Secondary node key / Secondary key (SN key)

[0141] A secondary key refers to the key used for communication between the UE and the SN. This secondary key can be denoted as k_SN. Specifically, the UE and SN can further derive the key k_UP for user plane data security processing and the key k_RRC for control plane signaling security processing using k_SN. The PDCP layer of the UE and SN uses k_UP and k_RRC to perform secure processing of user plane data and control plane signaling, respectively.

[0142] It should be understood that some bearers can be configured to use PDCP of the SN and RLC of the MN, such as the SN-terminated MCG bearer that terminates at the secondary station, where MCG stands for master cell group. These bearers also use secondary keys for security processing. That is, if the PDCP layer is at the SN, then the secondary key is used.

[0143] It should also be understood that the auxiliary station key can be calculated and derived based on the master station key.

[0144] In mobile communication systems, the movement of terminal devices causes changes in the communication link between the terminal device and the access network equipment, potentially leading to cell handover or access network equipment handover. When a terminal device hands over from a source access network equipment to a target access network equipment, a key update is required. This application provides a method to accurately update keys during handover scenarios, ensuring uninterrupted communication for the terminal device and a positive user experience.

[0145] Figure 3 This is a schematic flowchart illustrating a communication method provided in an embodiment of this application. Figure 3 As shown, the method includes the following steps:

[0146] 301, MN1 sends a handover request to MN2. Correspondingly, MN2 receives the handover request from MN1.

[0147] Among them, MN1 is the source master station that provides services to the terminal device, and MN2 is the target master station for the terminal device to switch.

[0148] It should be understood that the handover request information includes the master key (e.g., k_gNB) determined by MN1 for communication between MN2 and the terminal device. For details on how MN1 determines the master key for communication between MN2 and the terminal device, please refer to existing solutions; these details will not be repeated here.

[0149] It should also be understood that the handover request information may also include the identification information of the SN, which can be used to indicate to MN2 the identity of the SN that the current terminal device is using to communicate using the DC architecture.

[0150] 302, MN2 sends an SN add request message to SN. Correspondingly, SN receives the add request message from MN2.

[0151] For example, after MN2 receives a handover request from MN1, MN2 sends the add request to SN based on the handover request.

[0152] It should be understood that after receiving the handover request information, if MN2 determines that the SN in the DC architecture does not need to be changed, MN2 sends an add request information to the SN based on the SN's identification information in the handover request information. This add request information includes the secondary station key (e.g., k_SN) to be used for communication between the SN and the terminal device. Specifically, MN2 determines the secondary station key between the SN and the terminal device based on the primary station key and a counter value in the handover request information. This counter value can be represented as sn-counter or sk-counter. MN2 deduces the secondary station key between the SN and the terminal device based on the primary station key received in step 301 and the counter value. Detailed deduction processes can be found in existing schemes and will not be elaborated here.

[0153] 303, SN sends an SN add request confirmation message to MN2. Correspondingly, MN2 receives the add request confirmation message from SN.

[0154] It should be understood that this add request confirmation information is used to respond to the add request information in step 302 above.

[0155] 304. MN2 sends a handover request confirmation message to MN1. Correspondingly, MN1 receives the handover confirmation request message from MN2.

[0156] It should be understood that this handover request confirmation information can be used to indicate that the SN remains unchanged or does not need to be changed in the scenario of terminal device handover. Specifically, this handover request confirmation information can be used to indicate that the relevant context information of the terminal device is retained in the SN.

[0157] It should be understood that the switch request confirmation message includes a count value used to deduce the secondary station key.

[0158] 305, MN1 sends a release request message to SN. Correspondingly, SN receives the release request message from MN1.

[0159] It should be understood that the release request information can be used to instruct the terminal device to retain context-related information in the SN.

[0160] 306. SN sends an SN release request confirmation message to MN1. Correspondingly, MN1 receives the SN release request confirmation message from SN.

[0161] 307: MN1 sends RRC reconfiguration information to the terminal device. Correspondingly, the terminal device receives the RRC reconfiguration information from MN1.

[0162] It should be understood that this RRC reconfiguration information is used to trigger the terminal device to perform a handover.

[0163] It should also be understood that the RRC reconfiguration information includes parameters (e.g., NCC) used by the terminal device to determine the master station key used for communication with MN2. Accordingly, after receiving the NCC, the terminal device calculates and derives the master station key (e.g., k_gNB) used for communication with MN2 based on the NCC. The detailed derivation process is similar to the derivation process in step 301 above where MN1 determines the master station key corresponding to the candidate master cell group of MN2; for details, please refer to the detailed description of the existing scheme.

[0164] It should also be understood that the RRC reconfiguration information includes parameters (e.g., counter values: sn-counter or sk-counter) used by the terminal device to determine the secondary station key used for communication with the SN. The terminal device can further calculate and deduce the secondary station key (e.g., k_SN) used for communication with the SN based on the master station key and counter value used for communication with MN2. The detailed deduction process is similar to the deduction process in step 302 above, and can be found in the detailed description of the existing scheme.

[0165] 308. The terminal device accesses MN2 via random access.

[0166] It should be understood that after the terminal device connects to MN2, the terminal device communicates with MN2 through the master station key determined in step 307, thereby ensuring the security of data and / or signaling transmission during the communication between the terminal device and MN2.

[0167] The communication involved in the embodiments of this application may include data transmission, signaling interaction, etc.

[0168] 309: The terminal device sends an RRC reconfiguration completion message to MN2.

[0169] 310: Terminal devices access the SN via random access.

[0170] It should be understood that after the terminal device connects to the SN, the terminal device communicates with the SN through the auxiliary station key determined in step 307, thereby ensuring the security of data and / or signaling transmission during the communication between the terminal device and the SN.

[0171] It should be understood that the above Figure 3This illustrates a DC network architecture where the master station providing services to a terminal device switches (from MN1 to MN2), while the SN remains unchanged. MN1 sends a switch request message to MN2, indicating the master station key used for communication between MN2 and the terminal device. MN2 determines the corresponding auxiliary station key based on the master station key used for communication between MN2 and the terminal device, and sends the auxiliary station key to the SN. This ensures that when the master station switches but the auxiliary station remains unchanged, the terminal device can align the auxiliary station key used for communication with the auxiliary station, thereby ensuring smooth communication and a good user experience for the terminal device.

[0172] Figure 4 This is a schematic flowchart illustrating another communication method provided in an embodiment of this application. Figure 4 As shown, the method includes the following steps:

[0173] 401, gNB1 sends a handover request message to the candidate gNBs (gNB2 and gNB3). Accordingly, gNB2 and gNB3 receive the handover request message from gNB1.

[0174] It should be understood that this handover request information is used to request the candidate gNB to provide configuration information for the candidate cell group.

[0175] It should also be understood that gNB1 is the source network device that provides services to the terminal device, while gNB2 and gNB3 are candidate network devices that provide services to the terminal device.

[0176] 402. Candidate gNBs (gNB2 and gNB3) send handover request confirmation messages to gNB1 respectively. Correspondingly, gNB1 receives handover request confirmation messages from gNB2 and gNB3.

[0177] It should be understood that the handover request confirmation information includes the configuration information of the candidate cell group of the candidate gNB, and a candidate cell group includes at least one cell. For example, the handover request confirmation information for gNB2 includes the configuration information of the candidate cell group for gNB2, and the handover request confirmation information for gNB3 includes the configuration information of the candidate cell group for gNB3. The following will use the example of gNB2 providing Cell2 as a candidate cell and gNB3 providing Cell3 as a candidate cell to illustrate this. Figure 4 The embodiments shown are described by way of example.

[0178] 403, gNB1 sends RRC reconfiguration information to the terminal device. Correspondingly, the terminal device receives the RRC reconfiguration information from gNB1.

[0179] It should be understood that the RRC reconfiguration information includes the configuration information of the candidate cell groups for the candidate gNB. For example, the RRC reconfiguration information includes the configuration information of the candidate cell groups for gNB2 and gNB3.

[0180] The configuration information of the candidate cell group includes the configuration information that the terminal device should use when accessing the corresponding cell (e.g., Cell2 or Cell3), such as uplink physical channel configuration, downlink physical channel configuration, measurement configuration, bearer configuration, etc.

[0181] 404, gNB1 sends a handover command to the terminal device. Correspondingly, the terminal device receives the handover command from gNB1.

[0182] It should be understood that this handover command is used to trigger the terminal device to perform a handover. Specifically, the terminal device performs the handover based on the RRC reconfiguration information received in step 403.

[0183] Suppose that the handover command in step 404 indicates that the target cell of the terminal device is Cell2, meaning that the network device providing services to the terminal device is switching from gNB1 to gNB2. Based on the handover command and the Cell2 configuration information in the RRC reconfiguration information in step 403, the terminal device switches to Cell2. For example, this... Figure 4 The method shown also includes:

[0184] 405. The terminal device accesses gNB2's Cell2 based on Cell2's configuration information.

[0185] It should be understood that after a terminal device accesses Cell2, if its location changes or other reasons cause it to need to switch to the Cell3 cell of gNB3, then... Figure 4 The method shown may also include:

[0186] 406. gNB2 sends a handover command to the terminal device. Correspondingly, the terminal device receives the handover command from gNB2.

[0187] It should be understood that this handover command is used to trigger the terminal device to perform a handover. Specifically, the terminal device performs the handover based on the RRC reconfiguration information received in step 403.

[0188] Suppose that the handover command in step 406 indicates that the target cell of the terminal device is Cell3, meaning that the network device providing services to the terminal device is switching from gNB2 to gNB1. Based on the handover command and the configuration information of Cell3 in the RRC reconfiguration information in step 403, the terminal device switches to Cell3. For example, this... Figure 4 The method shown also includes:

[0189] 407. The terminal device accesses the gNB3's Cell3 based on the Cell3 configuration information.

[0190] It should be understood that the above Figure 4 The method described illustrates a mobility management technique where a terminal device is configured with multiple candidate cells, allowing it to perform multiple handovers within these candidate cells. For example, the terminal device first hands over from Cell1 corresponding to gNB1 to Cell2 corresponding to gNB2, and then from Cell2 to Cell3 corresponding to gNB3. This process of multiple handovers within multiple candidate cells can be termed "subsequent handover" technology.

[0191] Based on the embodiments provided in this application Figure 3 and Figure 4 The terminal device switching method shown, wherein, Figure 3 The method shown is primarily designed for single-transfer scenarios, enabling changes to the primary and secondary station keys when the MN changes while the SN remains constant. However, in subsequent transfer scenarios, the service primary station corresponding to the terminal device may change multiple times. Figure 3 All steps in the method shown need to be repeated, resulting in significant signaling overhead and transmission delay between the terminal device and the network device. This may lead to delays in business data transmission and affect user experience. Figure 4 The method shown can be applied to the "subsequent handover" technology, but it cannot be applied to the DC network architecture. In each subsequent handover, the corresponding auxiliary station key update process is not performed, which causes the terminal device and the SN to be unable to align the auxiliary station key, resulting in communication interruption of the terminal device and affecting the user experience.

[0192] In view of the above Figure 3 and Figure 4 To address the existing problems, this application provides another key update method. Figure 3 and Figure 4 The problems with the method shown.

[0193] It should be understood that the method provided in this application can be applied to the handover scenario where the service master station of the terminal device is switched over and the auxiliary station is maintained. The method provided in this application can also be applied to other handover technologies, such as Layer 1 / Layer 2 triggered mobility (LTM) handover technology and other subsequent handover technologies triggered by access network devices.

[0194] In technologies supporting subsequent handovers, the concepts of source cell / source access network equipment and target cell / target access network equipment are relative. In a handover, the cell the terminal device accesses before the handover can be called the source cell, and the cell it accesses after the handover can be called the target cell. For example, when the terminal device hands over from cell 1 to cell 2, cell 1 can be understood as the source cell for this handover, and cell 2 as the target cell. When the terminal device hands over from cell 2 to cell 3, cell 2 can be understood as the source cell for this handover, and cell 3 as the target cell.

[0195] Figure 5 This is a flowchart illustrating another communication method provided in an embodiment of this application. For example... Figure 5 As shown, the method includes the following steps:

[0196] 501, MN1 sends at least one handover request message to at least one candidate master station (e.g., MN2 and MN3). Accordingly, MN2 and MN3 respectively receive the handover request message sent by MN1.

[0197] It should be understood that, taking the handover request information received by MN2 as an example, this handover request information is used to request the configuration information of at least one candidate cell group of MN2. The configuration information of the at least one candidate cell group includes the configuration information of at least one candidate primary cell group.

[0198] It should also be understood that the switching request information sent by MN1 to MN2 and MN3 respectively can be sent at the same time or sent sequentially, and this application does not limit this.

[0199] 502, MN2 and MN3 respectively send SN add request information to SN. Correspondingly, SN receives SN add request information from MN2 and MN3.

[0200] For example, after MN2 and MN3 receive the handover request information from MN1, MN2 and MN3 respectively send SN add request information to SN based on the received handover request information.

[0201] In one possible implementation, the add request information sent by MN2 includes one or more of the following indications: information indicating that MN2 is a candidate communication device for terminal device handover, information indicating that MN2 is a candidate communication device for subsequent handover of terminal device, or information indicating that MN2 is a candidate communication device for terminal device handover across gNB or across CU.

[0202] In one possible implementation, the add request information sent by MN3 includes one or more of the following indications: information indicating that MN3 is a candidate communication device for terminal device handover, information indicating that MN3 is a candidate communication device for subsequent handover of terminal device, or information indicating that MN3 is a candidate communication device for terminal device handover across gNB or across CU.

[0203] It should be understood that the SN addition request information sent by MN2 or MN3 may or may not include the secondary station key indicated by MN2 or MN3. Assuming that the SN addition request information sent by MN2 to the SN includes the secondary station key, upon receiving the SN addition request information, the SN further determines whether the SN addition request information includes one or more of the following: information indicating that MN2 is a candidate communication device for terminal device handover, information indicating that MN2 is a candidate communication device for subsequent handover of the terminal device, or information indicating that MN2 is a candidate communication device for terminal device handover across gNB or across CU. If the SN addition request information includes these, the SN ignores the secondary station key included in the SN addition request information.

[0204] 503, SN sends SN add request confirmation messages to MN2 and MN3 respectively. Correspondingly, MN2 and MN3 receive the add request confirmation messages from SN.

[0205] It should be understood that this add request confirmation information is used to respond to the add request information in step 502 above.

[0206] 504. MN2 and MN3 send handover request confirmation messages to MN1 respectively. Correspondingly, MN1 receives handover confirmation request information from MN2 and MN3.

[0207] It should be understood that this handover request confirmation information can be used to indicate that the SN remains unchanged or does not need to be changed in the scenario of terminal device handover. Specifically, this handover request confirmation information can be used to indicate that the relevant context information of the terminal device is retained in the SN.

[0208] It should also be understood that, taking the handover request confirmation information sent by MN2 as an example, the handover request confirmation information sent by MN2 may include the configuration information of at least one candidate cell group of MN2 and at least one counter value (e.g., sk-counter / sn-counter). The configuration of one of the candidate cell groups in the configuration of the at least one candidate cell group may correspond to at least one counter value.

[0209] Suppose that the handover request confirmation information sent by MN2 to MN1 includes configuration information of a candidate cell group provided by MN2. This handover request confirmation information may include a candidate configuration identifier (e.g., identifier 1) corresponding to the configuration information of the candidate cell group provided by MN2, and identifier 1 corresponds to the configuration information of the candidate cell group and at least one count value corresponding to the configuration of the candidate cell group. Similarly, suppose the handover request confirmation information sent by MN3 to MN1 includes configuration information of a candidate cell group provided by MN3. This handover request confirmation information may include a candidate configuration identifier (e.g., identifier 2) corresponding to the configuration information of the candidate cell group provided by MN3, and identifier 2 corresponds to the configuration information of the candidate cell group and at least one count value corresponding to the configuration of the candidate cell group.

[0210] It should be understood that the configuration information of a candidate cell group includes the configuration information of the MCG. Optionally, the configuration information of the candidate cell group may also include the configuration information of the corresponding SCG. When a terminal device uses the configuration information of the candidate cell group, it will apply the configuration information of the MCG corresponding to the candidate cell group, and optionally, it may also apply the configuration information of the SCG corresponding to the candidate cell group.

[0211] It should be understood that the method provided in this application will be described exemplarily below, taking as an example a candidate primary cell group that the terminal device accesses, which belongs to the candidate primary cell group (e.g., MN2 or MN3).

[0212] 505, MN1 sends RRC reconfiguration information to the terminal device. Correspondingly, the terminal device receives the RRC reconfiguration information from MN1.

[0213] It should be understood that the RRC reconfiguration information includes the configuration information of the candidate primary cell group of at least one candidate communication device (or candidate master station) in step 504 above. For example, the RRC reconfiguration information includes the configuration information of the candidate primary cell groups corresponding to MN2 and MN3.

[0214] Optionally, the RRC reconfiguration information may further include at least one count value corresponding to the candidate primary cell group configuration of at least one candidate communication device. For example, the RRC may also include at least one count value corresponding to the configuration of at least one candidate primary cell group of MN2, and at least one count value corresponding to the configuration of at least one candidate primary cell group of MN3.

[0215] 506, the terminal device sends the measurement result to MN1. Correspondingly, MN1 receives the measurement result from the terminal device.

[0216] It should be understood that after receiving the aforementioned RRC reconfiguration information, the terminal device can perform measurements on the candidate primary cell group based on the configuration information of at least one candidate primary cell group in the RRC reconfiguration information, and send the measurement results to MN1. The detailed process by which the terminal device determines the measurement results can be found in existing solutions.

[0217] Optionally, the terminal device can send the measurement result to MN1 via Layer 1 (L1, physical layer).

[0218] 507, MN1 sends information #1 to the terminal device. Correspondingly, the terminal device receives information #1 from MN1.

[0219] It should be understood that after MN1 sends the RRC reconfiguration information to the terminal device, MN1 sends information #1 to the terminal device. This information #1 may also be called control information, and its specific name is not limited.

[0220] The information #1 may include one or more NCCs. When information #1 includes one NCC, the NCC corresponds to the configuration of all candidate primary cell groups. When information #1 includes multiple NCCs, each NCC corresponds to the configuration of a candidate primary cell group.

[0221] For example, information #1 includes an NCC (Network Control Code) that corresponds to the candidate primary cell groups MN2 and MN3. This NCC can be used by the terminal device to determine the master station key for communication with the candidate primary cell group MN2, and also for determining the master station key for communication with the candidate primary cell group MN3. It should be understood that the input parameters used for master station key derivation include not only the NCC but also other parameters (such as cell identifiers). Therefore, even if the candidate primary cell groups MN2 and MN3 share the same NCC, the master station key corresponding to the candidate primary cell group MN2 will be different from the master station key corresponding to the candidate primary cell group MN3, and there will be no key duplication issue.

[0222] For example, information #1 includes two NCCs, which correspond to the candidate primary cell group of MN2 (e.g., primary cell group #1) and the candidate primary cell group of MN3 (e.g., primary cell group #2), respectively. For example, NCC #1 corresponds to primary cell group #1, and this NCC #1 can be used by the terminal device to determine the master station key for communicating with primary cell group #1; similarly, NCC #2 corresponds to primary cell group #2, and this NCC #2 can be used by the terminal device to determine the master station key for communicating with primary cell group #2.

[0223] Optionally, the information #1 may further include at least one count value corresponding to the candidate primary cell group configuration of MN2 and at least one count value corresponding to the candidate primary cell group configuration of MN3. The count value may be a random value, or it may be a value related to the number of times the secondary cell key corresponding to the SN has been updated.

[0224] It should be understood that if the RRC reconfiguration information in step 505 does not include at least one count value corresponding to the configuration of at least one candidate primary cell group of MN2 and at least one count value corresponding to the configuration of at least one candidate primary cell group of MN3, then step 507 includes at least one count value corresponding to the configuration of at least one candidate primary cell group of MN2 and at least one count value corresponding to the configuration of at least one candidate primary cell group of MN3; if information #1 in step 507 does not include at least one count value corresponding to the configuration of at least one candidate primary cell group of MN2 and at least one count value corresponding to the configuration of at least one candidate primary cell group of MN3, then the RRC reconfiguration information in step 505 includes at least one count value corresponding to the configuration of at least one candidate primary cell group of MN2 and at least one count value corresponding to the configuration of at least one candidate primary cell group of MN3; or, both information #1 in step 507 and the RRC reconfiguration information in step 505 include at least one count value corresponding to the configuration of at least one candidate primary cell group of MN2 and at least one count value corresponding to the configuration of at least one candidate primary cell group of MN3.

[0225] It should also be understood that information #1 can be carried in RRC signaling, or in a medium access control control element (MAC CE) message, or in downlink control information (DCI). When information #1 is carried in a MAC CE message, step 507 and step 508 below can be combined into one step.

[0226] It should also be understood that after receiving information #1, the terminal device can store information #1 locally on the terminal device. When switching to a candidate cell group, the terminal device can use the NCC corresponding to the candidate cell group and the count value used for secondary station key deduction to deduce the primary station key and the secondary station key.

[0227] It should also be understood that there is no restriction on the order of execution between steps 506 and 507.

[0228] 508, MN1 sends a handover command to the terminal device. Correspondingly, the terminal device receives the handover command from MN1.

[0229] It should be understood that the handover command is used to indicate the identifier of the target primary cell group for the terminal device to hand over. The identifier of the target primary cell group is the candidate configuration identifier corresponding to the configuration information of a candidate primary cell group. The target primary cell group may be determined by MN1 based on the measurement report in step 506.

[0230] Assuming MN2 is the target primary station for terminal device handover, the target primary cell group belongs to at least one candidate primary cell group of MN2. For example, the at least one candidate primary cell group of MN2 includes primary cell group #1-1 and primary cell group #1-2, where the configuration identifier corresponding to primary cell group #1-1 is 1-1, and the configuration identifier corresponding to primary cell group #1-2 is 1-2. Assuming MN1 determines that the target primary cell group of the terminal device is candidate primary cell group #1-1 of MN2, the identifier of the target primary cell group of the terminal device indicated by the handover command can be 1-1.

[0231] It should also be understood that the candidate primary cell group may include one primary cell (PCell), and optionally, one or more secondary cells (SCell), which is not limited in this application.

[0232] It should also be understood that the switching command can be transmitted over the MAC CE.

[0233] 509, MN1 sends message #2 to MN2. Correspondingly, MN2 receives message #2 from MN1.

[0234] Suppose MN1 determines that the target master station to which the terminal device will switch is MN2, meaning that the terminal device's serving master station will switch from MN1 to MN2. Here, information #2 is used to indicate that the terminal device's serving master station will switch to MN2, or information #2 is used to indicate the candidate configuration identifier corresponding to the target master cell group to which the terminal device will switch, where the target master cell group belongs to the candidate master cell group of MN2.

[0235] Optionally, this information #2 may include the master station key determined by MN1 corresponding to the target primary cell group of MN2. This target primary cell group belongs to the candidate primary cell group of MN2. The master station key corresponds to the target primary cell group configuration of MN2.

[0236] It should be understood that the target cell group of MN2 includes one primary cell. Optionally, the target cell group may also include one or more secondary cells. All cells included in the target cell group of MN2 can communicate with the terminal device through the master station key; that is, the terminal device can communicate with any cell in the target cell group of MN2 through the master station key. Specifically, assuming that both the primary and secondary cells included in the carrier aggregation belong to the target cell group of MN2, the terminal device can communicate with the cells of the carrier aggregation through the master station key.

[0237] It should be understood that the master key can also be carried in other signaling (such as cell change notification information or LTM cell change notification message) and sent to MN2. When the master key is sent to MN2 through other separate signaling, MN1 can send information #2 to MN2 before or after sending the master key; this application does not limit the order of execution.

[0238] It should also be understood that there is no restriction on the order of execution between steps 508 and 509.

[0239] 510, MN2 sends the auxiliary station key #1 to SN. Correspondingly, SN receives the auxiliary station key #1 from MN2.

[0240] It should be understood that after receiving the master station key from MN1, MN2 determines the auxiliary station key (e.g., auxiliary station key #1) based on the master station key and at least one count value corresponding to the configuration of the target master cell group. MN2 sends the auxiliary station key #1 to the SN for subsequent communication between the SN and the terminal device when the terminal device accesses the target master cell group of MN2.

[0241] As an example, suppose MN2's target primary cell group configuration corresponds to a count value. Then, MN2 calculates and deduces the secondary cell key #1 based on the primary cell key corresponding to the target primary cell group configuration and the count value. Alternatively, suppose MN2's target primary cell group configuration corresponds to multiple count values. Then, MN2 calculates and deduces the secondary cell key #1 based on the primary cell key corresponding to the target primary cell group configuration and the first unused count value among the multiple count values.

[0242] Optionally, after receiving the secondary station key #1, the SN stores the secondary station key #1 instead of immediately using it to establish PDCP. The SN waits for the terminal device to complete its connection to the SN before using the secondary station key to re-establish PDCP.

[0243] It should also be understood that the auxiliary station key #1 in step 510 can be carried in the SN reconfiguration completion information sent by MN2 to SN.

[0244] It should also be understood that the auxiliary station key #1 in step 510 can be carried in the SN modification request information (or SN modification request message).

[0245] 511, The terminal device accesses the target primary cell group of MN2.

[0246] It should be understood that after receiving the handover command from MN1 in step 508, the terminal device can calculate and deduce the master station key corresponding to the target primary cell group configuration of MN2 based on the handover command and the NCC corresponding to the target primary cell group of MN2 stored locally in information #1. The terminal device then accesses the target primary cell group of MN2 based on this master station key and conducts secure communication with MN2.

[0247] Optionally, the terminal device determines the auxiliary station key between the terminal device and the SN based on the master station key corresponding to the target master cell group of MN2 and at least one count value configured for the target master cell group.

[0248] As an example, suppose that the target primary cell group is configured with a corresponding count value, then the terminal device calculates and deduces the secondary cell key based on the primary cell key corresponding to the target primary cell group configuration and the count value; suppose that the target primary cell group is configured with multiple count values, then the terminal device calculates and deduces the secondary cell key based on the primary cell key corresponding to the target primary cell group configuration and the first unused count value among the multiple count values.

[0249] As another example, the count value used to deduce the secondary station key for each candidate primary cell group can be the same. In this case, the information #1 received by the terminal device in step 507 can include only one count value, which corresponds to all candidate primary cell groups.

[0250] 512, Terminal equipment accesses SN.

[0251] It should be understood that after the terminal device accesses the target primary cell group of MN2, the terminal device communicates with the SN according to the secondary station key determined in step 511, so that the terminal device and the SN can still communicate and maintain high-speed data transmission even when the target primary station of the terminal device is switched to MN2.

[0252] It should be understood that steps 501 to 512 above exemplify the process of switching the service master station of the terminal device from MN1 to MN2 while keeping the SN unchanged. Next, steps 513 to 518 will exemplify the process of switching the service master station of the terminal device from MN2 to MN3 after switching from MN1 to MN2, while keeping the SN unchanged. For the third and fourth master station switches performed by the terminal device, while the secondary station remains unchanged, the relevant process for the second switch can be referenced.

[0253] 513, MN2 sends information #3 to the terminal device, and the terminal device receives information #3 from MN2 accordingly.

[0254] It should be understood that information #3 includes one or more NCCs. When information #3 includes one NCC, the NCC corresponds to the configuration of all candidate primary cell groups of the candidate primary station. When information #3 includes multiple NCCs, each NCC may correspond to the configuration of each candidate primary cell group of the candidate primary station.

[0255] Assuming the candidate MN includes MN3, information #3 includes an NCC that corresponds to all candidate primary cell group configurations for MN3. For example, information #3 includes an NCC (e.g., NCC#3) that corresponds to the candidate primary cell group configuration for MN3. This NCC#3 can be used by the terminal device to determine the master station key for communication with the candidate primary cell group of MN3.

[0256] The candidate MN can include multiple MNs, such as MN3, MN4, etc. In this example, MN3 is used as the candidate MN in this application. This message #3 is similar to message #1 sent by MN1 in step 507 above. For details, please refer to the detailed description of information #1 above.

[0257] It should also be understood that after the terminal device's service master station switches from MN1 to MN2, MN2 can initiate a path switch to the core network device (such as the AMF gateway) and obtain the NCC value corresponding to the candidate MN from the AMF network element. For the specific process, please refer to the existing solution, which will not be elaborated here.

[0258] 514, MN2 sends a handover command to the terminal device. Correspondingly, the terminal device receives the handover command from MN2.

[0259] It should be understood that this handover command is used to indicate the identifier of the target primary cell group for the terminal device to hand over. Assuming the target primary cell is MN3, the identifier of this target primary cell group belongs to the candidate configuration identifier corresponding to the candidate primary cell group of MN3. For example, the candidate primary cell groups of MN3 include primary cell group #2-1 and primary cell group #2-2, where the configuration identifier corresponding to primary cell group #2-1 is 2-1, and the configuration identifier corresponding to primary cell group #2-2 is 2-2. Assuming the target primary cell group corresponds to primary cell group #2-1 of at least one candidate primary cell group of MN3, this handover command can indicate that the identifier of the target primary cell group for the terminal device is 2-1.

[0260] It should be understood that step 514 is similar to step 508 above.

[0261] 515, MN2 sends message #4 to MN3. Correspondingly, MN3 receives message #4 from MN2.

[0262] It should be understood that, assuming MN2 determines that the target master station to which the terminal device will switch is MN3, the terminal device will switch from MN2 to MN3. Here, information #4 is used to indicate that the terminal device's serving master station will switch to MN3, or information #4 is used to indicate the candidate configuration identifier corresponding to the target master cell group to which the terminal device will switch, where the target master cell group belongs to the candidate master cell group of MN3.

[0263] Optionally, this information #4 may include the master station key determined by MN2 corresponding to the target primary cell group of MN3. This target primary cell group belongs to the candidate primary cell group of MN3. The master station key corresponds to the target primary cell group configuration of MN3.

[0264] It should be understood that the master station key corresponding to the target primary cell group of MN3 can be carried in information #4 and sent to MN3, or sent to MN3 through other separate signaling; this application does not limit this. Assuming that the master station key is sent to MN3 through other separate signaling, MN2 can send information #4 to MN3 before or after sending the master station key; this application does not limit the order of execution.

[0265] It should be understood that there is no specific order of execution between steps 514 and 515.

[0266] It should also be understood that step 515 is similar to step 509 above.

[0267] 516, MN3 sends auxiliary station key #2 to SN. Correspondingly, SN receives auxiliary station key #2 from MN3.

[0268] It should be understood that after receiving the master station key from MN2, MN3 determines the auxiliary station key (e.g., auxiliary station key #2) based on the master station key and at least one corresponding count value configured for the target master cell group. MN3 sends the auxiliary station key #2 to the SN for subsequent communication between the SN and the terminal device when the terminal device accesses the target master cell group of MN3.

[0269] As an example, suppose the target primary cell group configuration of MN3 corresponds to a count value. Then, MN3 calculates and deduces the auxiliary cell key #2 based on the primary station key corresponding to the target primary cell group configuration of MN3 and the count value. Alternatively, suppose the target primary cell group configuration of MN3 corresponds to multiple count values. Then, MN3 calculates and deduces the auxiliary cell key #2 based on the primary station key corresponding to the target primary cell group configuration of MN3 and the first unused count value among the multiple count values.

[0270] Optionally, after receiving the secondary station key #2, the SN stores the secondary station key #2 instead of immediately using it to establish PDCP. The SN waits for the terminal device to complete its access to the SN before using the secondary station key to re-establish PDCP.

[0271] It should also be understood that the auxiliary station key #2 in step 516 can be carried in the SN reconfiguration completion information sent by MN3 to SN.

[0272] It should also be understood that the auxiliary station key #2 in step 516 can be carried in the SN modification request information (or SN modification request message).

[0273] It should also be understood that step 516 is similar to step 510 above.

[0274] 517, The terminal device accesses the target primary cell group corresponding to MN3.

[0275] It should be understood that after receiving the handover command from MN2 in step 514, the terminal device can calculate and deduce the master station key corresponding to the target primary cell group configuration of MN3 based on the handover command and the NCC corresponding to the target primary cell group of MN3 stored locally in information #3. The terminal device then accesses the target primary cell group of MN3 based on this master station key and conducts secure communication with MN3.

[0276] Optionally, the terminal device determines the auxiliary station key between the terminal device and the SN based on the master station key corresponding to the target master cell group of MN3 and at least one count value configured for the target master cell group.

[0277] As an example, suppose that the target primary cell group configuration of MN3 corresponds to a count value. Then the terminal device calculates and deduces the secondary cell key based on the primary station key corresponding to the target primary cell group configuration of MN3 and the count value. Suppose that the target primary cell group configuration of MN3 corresponds to multiple count values. Then the terminal device calculates and deduces the secondary cell key based on the primary station key corresponding to the target primary cell group configuration of MN3 and the first unused count value among the multiple count values.

[0278] As another example, the count value used to deduce the auxiliary station key for each candidate primary cell group can be the same. In this case, the information #3 received by the terminal device in step 513 can include only one count value, which corresponds to all candidate primary cell groups.

[0279] 518, Terminal equipment accesses SN.

[0280] It should be understood that after the terminal device accesses the target primary cell group of MN3, the terminal device communicates with the SN according to the secondary station key determined in step 517, which can ensure that the terminal device and the SN can still communicate and maintain high-speed data transmission even when the target primary station of the terminal device is switched to MN3.

[0281] Based on the above Figure 5 The method shown allows for the switching of the primary station providing services to the terminal device within a DC network architecture, while the secondary station remains unchanged. The terminal device can promptly align with the updated secondary station key, ensuring that the terminal device can still use the DC architecture after the switch, maintaining high-speed data transmission and guaranteeing user experience.

[0282] Figure 6 This is a flowchart illustrating another key update method provided in an embodiment of this application. For example... Figure 6 As shown, the method includes the following steps:

[0283] 601, MN1 sends at least one handover request message to at least one candidate master station (e.g., MN2 and MN3). Accordingly, MN2 and MN3 respectively receive the handover request message sent by MN1.

[0284] 602, MN2 and MN3 respectively send SN add request information to SN. Correspondingly, SN receives SN add request information from MN2 and MN3.

[0285] 603, SN sends an SN add request confirmation message to MN2 and MN3. Accordingly, MN2 and MN3 receive the add request confirmation message from SN.

[0286] 604. MN2 and MN3 send handover request confirmation messages to MN1 respectively. Correspondingly, MN1 receives handover confirmation request information from MN2 and MN3.

[0287] 605, MN1 sends RRC reconfiguration information to the terminal device. Correspondingly, the terminal device receives the RRC reconfiguration information from MN1.

[0288] 606, the terminal device sends the measurement result to MN1. Correspondingly, MN1 receives the measurement result from the terminal device.

[0289] 607, MN1 sends information #1 to the terminal device. Correspondingly, the terminal device receives information #1 from MN1.

[0290] It should be understood that Figure 6 Steps 601 to 607 in the above are the same as those in the previous steps. Figure 5 Steps 501 to 507 are similar; for details, please refer to the above. Figure 5 Detailed introduction in the text.

[0291] 608, MN1 sends message #5-1 to MN2, and MN1 sends message #5-2 to MN3. Correspondingly, MN2 receives message #5-1 from MN1, and MN3 receives message #5-2 from MN1.

[0292] It should be understood that MN1 determines MN2 and MN3 as candidate master stations for terminal device handover. MN1 can determine the master station key corresponding to the configuration of the candidate master cell group for each candidate MN, and instruct the corresponding candidate MN to the master station key corresponding to the configuration of the candidate master cell group for each candidate MN. Among them, information #5-1 includes the master station key corresponding to the configuration of the candidate master cell group for MN2; information #5-2 includes the master station key corresponding to the configuration of the candidate master cell group for MN3.

[0293] It should also be understood that MN1 can send information #5-1 and information #5-2 to MN2 and MN3 simultaneously, or sequentially, without limitation by this application.

[0294] It should also be understood that after MN2 receives the master key corresponding to the candidate primary cell group configuration of MN2, MN2 will not immediately use the master key to communicate with the terminal device. Instead, it will store the master key locally on MN2. When the terminal device switches to MN2, MN2 will use the master key to communicate with the terminal device. After MN3 receives the master key corresponding to the candidate primary cell group configuration of MN3, MN3 will not immediately use the master key to communicate with the terminal device. Instead, it will store the master key locally on MN3. When the terminal device switches to MN3, MN3 will use the master key to communicate with the terminal device.

[0295] 609. MN2 sends auxiliary station key #1 to SN, and MN3 sends auxiliary station key #2 to SN. Accordingly, SN receives auxiliary station key #1 from MN2 and auxiliary station key #2 from MN3.

[0296] It should be understood that, assuming that both MN2 and MN3's candidate primary cell groups include a primary cell group, upon triggering step 608, MN2 sends secondary station key #1 to the SN, and MN3 sends secondary station key #2 to the SN. The secondary station keys correspond to the primary cell group configuration. The SN, upon receiving secondary station key #1 and secondary station key #2, can store them locally. When the terminal device's target primary station switches from MN1 to MN2 or MN3, or when the terminal device accesses the candidate primary cell group corresponding to MN2 or MN3, the corresponding secondary station key is selected to communicate with the terminal device.

[0297] It should also be understood that detailed explanations of how MN2 determines the secondary station key #1 corresponding to the candidate primary cell group of MN2, and how MN3 determines the secondary station key #2 corresponding to the candidate primary cell group of MN3, can be found above. Figure 5 The content in [the document / article].

[0298] It should also be understood that the secondary station key #1 received by the SN is associated with the identifier of the candidate primary cell group of MN2 and / or the candidate configuration identifier of the candidate primary cell group, and the secondary station key #2 is associated with the identifier of the candidate primary cell group of MN3 and / or the candidate configuration identifier of the candidate primary cell group.

[0299] 610, MN1 sends a handover command to the terminal device. Correspondingly, the terminal device receives the handover command from MN1.

[0300] It should be understood that step 610 is related to the above. Figure 5 Step 508 is similar.

[0301] 611, MN1 sends message #2 to MN2. Correspondingly, MN2 receives message #2 from MN1.

[0302] Suppose MN1 determines that the target master station to which the terminal device will switch is MN2, meaning that the terminal device's serving master station will switch from MN1 to MN2. Here, information #2 is used to indicate that the terminal device's serving master station will switch to MN2, or information #2 is used to indicate the candidate configuration identifier corresponding to the target master cell group to which the terminal device will switch, where the target master cell group belongs to the candidate master cell group of MN2.

[0303] Optionally, the information #2 may also include information about the target primary cell group for instructing the terminal device to switch, the target primary cell group belonging to the candidate primary cell group of MN2.

[0304] It should be understood that there is no restriction on the order of execution between steps 610 and 611.

[0305] 612, The terminal device accesses the target primary cell group corresponding to MN2.

[0306] It should be understood that after receiving the handover command from MN1 in step 610, the terminal device can calculate and deduce the master station key corresponding to the target primary cell group configuration of MN2 based on the NCC corresponding to the target primary cell group of MN2 stored locally in information #1. The terminal device accesses the target primary cell group of MN2 according to the master station key and conducts secure communication with MN2.

[0307] Optionally, the terminal device determines the auxiliary station key between the terminal device and the SN based on the master station key corresponding to the target master cell group of MN2 and at least one count value configured for the target master cell group.

[0308] As an example, suppose that the target primary cell group configuration of MN2 corresponds to one count value. Then, the terminal device calculates and deduces the secondary cell key based on the primary station key corresponding to the target primary cell group configuration of MN2 and the count value. Alternatively, suppose that the target primary cell group configuration of MN2 corresponds to multiple count values. Then, the terminal device calculates and deduces the secondary cell key based on the primary station key corresponding to the target primary cell group configuration of MN2 and the first unused count value among the multiple count values. As another example, the count value used to deduce the secondary cell key for each candidate primary cell group can be the same. In this case, the information #1 received by the terminal device in step 607 can include only one count value, which corresponds to all candidate primary cell groups.

[0309] 613, MN2 sends an SN reconfiguration completion message to SN. Correspondingly, SN receives the SN reconfiguration completion message from MN2.

[0310] Optionally, the SN reconfiguration completion information may include the identifier of the target primary cell group and / or the candidate configuration identifier of the target primary cell group. For example, the identifier of the target primary cell group belongs to the identifier of the candidate primary cell group of MN2, and the candidate configuration identifier of the target primary cell group belongs to the candidate configuration identifier of the candidate primary cell group of MN2.

[0311] It should be understood that the identifier of the target primary cell group and / or the candidate configuration identifier of the target primary cell group can be transmitted through separate signaling, without needing to complete information retransmission through SN reconfiguration. This step 613 is optional.

[0312] 614, Terminal equipment accesses SN.

[0313] It should be understood that after the terminal device accesses the target primary cell group of MN2, the terminal device communicates with the SN according to the corresponding auxiliary station key configured for the target primary cell group of MN2. This enables the terminal device to continue communicating with the SN and maintain high-speed data transmission even when the target primary station of the terminal device is switched to MN2.

[0314] It should also be understood that, assuming the SN receives multiple secondary station keys, the SN can select the secondary station key corresponding to the target primary cell group from these multiple secondary station keys in the following manner:

[0315] Method 1: When the SN reconfiguration completion information in step 613 includes the identifier of the target primary cell group and / or the candidate configuration identifier of the target primary cell group, the SN can select an auxiliary station key for communication with the terminal device from multiple auxiliary station keys (e.g., auxiliary station key #1 and auxiliary station key #2) based on the identifier of the target primary cell group and / or the candidate configuration identifier of the target primary cell group. Assuming the terminal device's serving primary station switches from MN1 to MN2, the identifier of the target primary cell group in the SN reconfiguration completion information belongs to the identifier of the candidate primary cell group of MN2, and the candidate configuration identifier of the target primary cell group belongs to the candidate configuration identifier of the candidate primary cell group of MN2. The SN selects auxiliary station key #1 corresponding to the target primary cell group from auxiliary station key #1 and auxiliary station key #2 based on the identifier of the target primary cell group and / or the candidate configuration identifier of the target primary cell group, and communicates with the terminal device through auxiliary station key #1.

[0316] Method 2: In the information accessed by the terminal device to the SN, the terminal device indicates the identifier of the target primary cell group and / or the candidate configuration identifier of the target primary cell group in the uplink information. The SN receives the uplink information from the terminal device and, based on the identifier of the target primary cell group and / or the candidate configuration identifier of the target primary cell group in the uplink information, determines that the target primary cell group belongs to the candidate primary cell group of MN2. Based on the identifier of the target primary cell group and / or the candidate configuration identifier of the target primary cell group, the SN selects the auxiliary station key #1 corresponding to the target primary cell group from auxiliary station key #1 and auxiliary station key #2, and communicates with the terminal device through auxiliary station key #1.

[0317] Method 3: During the random access process initiated by the terminal device, the terminal device carries a first identifier, which corresponds one-to-one with the candidate primary cell group configuration. This first identifier can be a cell-radionetwork temporary identifier (C-RNTI). During the random access process, the terminal device sends the first identifier to the SN. Accordingly, the SN determines that the target primary cell group belongs to the candidate primary cell group of MN2 based on the first identifier. The SN then selects the secondary station key #1 corresponding to the target primary cell group from secondary station key #1 and secondary station key #2, and communicates with the terminal device through the secondary station key #1.

[0318] In step 603, during the SN adding request confirmation information, the SN can instruct MN2 and MN3 to indicate at least one second identifier, where the at least one second identifier includes the first identifier. In step 605, during the RRC reconfiguration information, MN2 and MN3 are respectively instructed to the terminal device, where the at least one second identifier is used to identify the candidate primary cell group corresponding to MN2 and MN3. During the random access process, the terminal device sends information to the SN carrying the first identifier corresponding to the target primary cell group of the target MN. Accordingly, the SN determines the secondary station key corresponding to the target primary cell group based on the first identifier.

[0319] Method 4: Different candidate primary cell groups are configured with different random access resources. During the random access process, the terminal device initiates random access to the SN using the random access resources of the secondary cell group corresponding to the target primary cell group. Accordingly, the SN determines that the target primary station is MN2 and that the target primary cell group belongs to the candidate primary cell group of MN2 based on the terminal device's random access resources. The SN further selects the secondary station key #1 corresponding to the target primary cell group from the secondary station key #1 and secondary station key #2 based on the random access resources to communicate with the terminal device.

[0320] In step 603, during the SN adding request confirmation information, the SN can instruct MN2 and MN3 to indicate at least one random access resource, where the random access resources for the secondary cell groups corresponding to the candidate primary cell groups of MN2 and MN3 are different. In step 605, during the RRC reconfiguration information, MN2 and MN3 respectively instruct the terminal device to use the random access resources, which are used to identify the candidate primary cell groups corresponding to MN2 and MN3. During the random access process, the terminal device sends information to the SN using the random access resources corresponding to the target primary cell group. Accordingly, the SN determines the secondary station key corresponding to the target primary cell group based on the random access resources used by the terminal device.

[0321] Optionally, the random access resource includes a random access preamble and / or a random access timing indicator.

[0322] It should also be understood that after the SN selects the corresponding secondary station key for the target primary cell group of MN2, the SN deletes other secondary station keys stored locally in step 609. For example, if the SN chooses to use secondary station key #1 to communicate with the terminal device, then the SN deletes secondary station key #2.

[0323] It should also be understood that steps 601 to 614 above exemplarily illustrate the process of the terminal device's service master station switching from MN1 to MN2 for the first time, while the SN remains unchanged. Next, steps 615 to 622 will be used to exemplarily illustrate the process of the terminal device's service master station switching from MN2 to MN3, while the SN remains unchanged. For the third and fourth master station switching operations performed by the terminal device, while the secondary station remains unchanged, the process of the second switching described above can be referenced.

[0324] 615, MN2 sends information #6 to the terminal device. Correspondingly, the terminal device receives information #6 from MN2.

[0325] It should be understood that information #6 includes one or more NCCs. When information #6 includes one NCC, the one NCC corresponds to the configuration of all candidate primary cell groups of the candidate primary station. When information #6 includes multiple NCCs, each of the multiple NCCs can correspond to the configuration of each candidate primary cell group of the candidate primary station.

[0326] Assuming the candidate MN includes MN3, information #6 includes an NCC that corresponds to all candidate primary cell group configurations for MN3. For example, information #6 includes an NCC (e.g., NCC#3) that corresponds to the candidate primary cell group configuration for MN3. This NCC#3 can be used by the terminal device to determine the master station key for communication with the candidate primary cell group of MN3.

[0327] The candidate MN can include multiple MNs, such as MN3, MN4, etc. In this example, MN3 is used as the candidate MN in this application. Message #6 is similar to message #1 sent by MN1 in step 607 above. For details, please refer to the detailed description of information #1 above.

[0328] 616, MN2 sends message #7 to MN3. Correspondingly, MN3 receives message #7 from MN2.

[0329] It should be understood that MN2 determines MN3 as the candidate master station for terminal device handover. MN2 can determine the master station key corresponding to the candidate master cell group configuration of each MN in the candidate MN, and indicate the master station key corresponding to the candidate master cell group configuration of each candidate MN to the corresponding candidate MN. Assuming that the candidate MN includes MN3, then message #7 includes the master station key corresponding to the candidate master cell group configuration of MN3.

[0330] 617, MN3 sends the auxiliary station key #3 to SN. Accordingly, SN receives the auxiliary station key #3 from MN3.

[0331] It should be understood that, triggered by step 616, MN3 sends the secondary station key #3 to SN. SN receives the secondary station key #3 and stores it locally. When the target primary station of the terminal device switches from MN2 to MN3, and the target primary cell group accessed by the terminal device belongs to the candidate primary cell group of MN3, SN selects the secondary station key corresponding to the target primary cell group to communicate with the terminal device.

[0332] Assume that MN3 corresponds to multiple candidate primary cell groups, such as candidate primary cell group #3-1, candidate primary cell group #3-2, and candidate primary cell group #3-3. The secondary station key corresponding to candidate primary cell group #3-1 determined by MN3 is secondary station key #3-1, the secondary station key corresponding to candidate primary cell group #3-2 is secondary station key #3-2, and the secondary station key corresponding to candidate primary cell group #3-3 is secondary station key #3-3. When the SN receives secondary station keys #3-1, #3-2, and #3-3 from MN3, it stores these keys locally. When a terminal device accesses candidate primary cell group #3-2 of MN3, the SN selects secondary station key #3-2 to communicate with the terminal device.

[0333] 618, MN2 sends a handover command to the terminal device. Correspondingly, the terminal device receives the handover command from MN2.

[0334] It should be understood that step 618 is similar to step 610 above.

[0335] 619, MN2 sends message #8 to MN3. Correspondingly, MN3 receives message #8 from MN2.

[0336] It should be understood that, assuming MN2 determines that the target master station for the terminal device to switch to is MN3, that is, the terminal device's service master station will switch from MN2 to MN3. Specifically, information #8 is used to indicate that the terminal device's service master station will switch to MN3.

[0337] Optionally, the information #8 may also include information about the target primary cell group for which the terminal device will switch, wherein the target primary cell group belongs to the candidate primary cell group of MN3; or, the information #8 may be used to indicate the candidate configuration identifier corresponding to the target primary cell group to which the terminal device will switch, wherein the target primary cell group belongs to the candidate primary cell group of MN3.

[0338] It should be understood that there is no specific order of execution between steps 618 and 619.

[0339] 620, The terminal device accesses the target primary cell group corresponding to MN3.

[0340] It should be understood that when the terminal device accesses the target primary cell group of MN3, which is a candidate primary cell group of MN3, step 620 is similar to the step 612 above where the terminal device accesses the target primary cell group corresponding to MN2. For details, please refer to the content of step 612 above.

[0341] 621, MN3 sends an SN reconfiguration completion message to SN. Correspondingly, SN receives the reconfiguration completion message from MN3.

[0342] Optionally, the SN reconfiguration completion information may include the identifier of the target primary cell group and / or the candidate configuration identifier of the target primary cell group. For example, the identifier of the target primary cell group belongs to the identifier of the candidate primary cell group of MN3, and the candidate configuration identifier of the target primary cell group belongs to the candidate configuration identifier of the candidate primary cell group of MN3.

[0343] It should be understood that the identifier of the target primary cell group and / or the candidate configuration identifier of the target primary cell group can be transmitted through separate signaling, without needing to complete information retransmission through SN reconfiguration. This step 613 is optional.

[0344] 622, Terminal equipment accesses SN.

[0345] It should be understood that after the terminal device accesses the target primary cell group of MN3, the terminal device communicates with the SN according to the secondary station key configured for the target primary cell group of MN3. This ensures that even when the target primary station of the terminal device is switched to MN3, communication between the terminal device and the SN can still be maintained, and high-speed data transmission can be preserved.

[0346] It should also be understood that steps 615 to 622 described above describe the case where the candidate MN only includes MN3. When the candidate MN includes multiple MNs, such as MN3 and MN4, the SN obtains multiple auxiliary station keys and, when the terminal device accesses the SN, selects the auxiliary station key corresponding to the target primary cell group configuration from among the multiple auxiliary station keys. Detailed examples can be found in the detailed descriptions in steps 608 to 614 above.

[0347] Based on the above Figure 6 The method shown allows candidate MNs (e.g., MN2 and MN3) to obtain the master station key corresponding to their respective master station's candidate master cell group in advance, and then deduce the auxiliary station key corresponding to the candidate master cell group in advance and instruct it to the SN. This ensures that the SN can obtain the auxiliary station key corresponding to the candidate master cell group of the candidate MN in advance, and ensures that when the terminal device performs MN handover, it can restore the data transmission on the SN side as early as possible, thus ensuring user experience.

[0348] The following will combine Figure 7 This application provides a detailed description of the technical solutions it offers. The embodiments of this application can be applied to multiple different scenarios, including... Figure 1 The scenario shown is not limited to this one. For example, it can also be applied to 5G or future communication networks.

[0349] It should be understood that the embodiments shown below do not particularly limit the specific structure of the execution subject of the method provided in the embodiments of this application. As long as it is possible to communicate according to the method provided in the embodiments of this application by running a program that records the code of the method provided in the embodiments of this application, for example, the execution subject of the method provided in the embodiments of this application can be a receiving end device or a sending end device, or a functional module in the receiving end device or the sending end device that can call and execute the program.

[0350] Without loss of generality, the communication method provided in this application embodiment will be described in detail using the interaction between the first communication device, the second communication device, the third communication device and the terminal device as an example. The first communication device can be the target master station (or a centralized unit (CU) or a distributed unit (DU) in the target master station) that the terminal device switches to; or, the second communication device can be an auxiliary station that provides services to the terminal device; or, the third communication device can be the source master station (or a centralized unit (CU) or a distributed unit (DU) in the source master station) that provides services to the terminal device.

[0351] Figure 7 This is a schematic flowchart illustrating a communication method provided in an embodiment of this application. Figure 7 As shown, the method may include the following steps:

[0352] 701, at least one candidate communication device sends at least one add request message to the second communication device. Accordingly, the second communication device receives at least one add request message from the at least one candidate communication device.

[0353] It should be understood that the second communication device is an auxiliary station that provides services to the terminal equipment.

[0354] It should also be understood that the configuration of the candidate cell group of the at least one candidate communication device corresponds to at least one add request message. For example, assuming the at least one candidate communication device includes two communication devices (e.g., a first communication device and a fourth communication device), the candidate cell group of the first communication device includes two cell groups (cell group #1 and cell group #2), and the candidate cell group of the fourth communication device includes two cell groups (cell group #3 and cell group #4), then the second communication device receives four add request messages, wherein these four add request messages correspond one-to-one with the configurations of cell group #1, cell group #2, cell group #3, and cell group #4, respectively.

[0355] The first communication device includes at least one candidate cell group (e.g., cell group #1), and the second communication device includes at least one candidate cell group (e.g., cell group #4).

[0356] Assume that the at least one candidate communication device includes a first communication device, which sends a first add request message to a second communication device. The first communication device is the target master station for terminal device switching.

[0357] In one possible implementation, after receiving a handover request from a third communication device, the at least one candidate communication device sends at least one add request to the second communication device. For example, as described above. Figure 5 Step 501 and Figure 6 Step 601 in the process.

[0358] In one possible implementation, taking the first communication device among at least one candidate communication device as an example, the addition request information of the first communication device may include one or more of the following: information indicating that the first communication device is a candidate communication device for terminal device handover, information indicating that the first communication device is a candidate communication device for subsequent handover of the terminal device, or information indicating that the first communication device is a candidate communication device for terminal device handover across base stations or across central units.

[0359] Similarly, the addition request information of the fourth communication device may include one or more of the following: information indicating that the fourth communication device is a candidate communication device for terminal device handover, information indicating that the fourth communication device is a candidate communication device for subsequent handover of the terminal device, or information indicating that the fourth communication device is a candidate communication device for terminal device handover across base stations or across central units.

[0360] It should be understood that the add request information sent by the at least one candidate communication device may also include a secondary station key indicated by the at least one candidate communication device. For example, if the add request information sent by the at least one candidate communication device includes at least one secondary station key corresponding to the configuration of at least one candidate primary cell group of the at least one candidate communication device, the second communication device, upon receiving the add request information, will ignore the secondary station key included in the add request information.

[0361] It should also be understood that a detailed example of step 701 can be found above. Figure 5 Step 502 in the middle, Figure 6 Step 602 in the process.

[0362] 702, the second communication device sends at least one add request confirmation message to at least one candidate communication device.

[0363] It should be understood that this add request confirmation information is used to respond to the add request information in step 701 above.

[0364] Optionally, the at least one add request information includes at least one second identifier and / or at least one random access resource. The random access resource is the random access resource of the secondary cell group corresponding to the target primary cell group. The at least one second identifier and / or at least one random access resource corresponds to the configuration of at least one candidate primary cell group for at least one candidate communication device.

[0365] For example, the second identifier in the at least one second identifier may be a C-RNTI. Wherein, the at least one second identifier includes a first identifier that corresponds to the configuration of the candidate primary cell group of the first communication device.

[0366] 703, at least one candidate communication device sends at least one handover request confirmation message to the third communication device. Accordingly, the third communication device receives at least one handover request confirmation message from at least one candidate communication device.

[0367] It should be understood that the at least one handover request confirmation information corresponds to the configuration of at least one candidate primary cell group of at least one candidate communication device. The at least one handover request information includes the configuration information of at least one candidate primary cell group of at least one candidate communication device and at least one count value corresponding to the configuration of each candidate primary cell group.

[0368] The third communication device is the source master station that provides services to the terminal equipment.

[0369] It should also be understood that a detailed example of step 703 can be found above. Figure 5 Step 504 in the middle, Figure 6 Step 604 in the process.

[0370] Optionally, the at least one handover request information includes at least one second identifier and / or at least one random access resource corresponding to the configuration of at least one candidate primary cell group of at least one candidate communication device.

[0371] 704. The third communication device sends RRC reconfiguration information to the terminal device. Correspondingly, the terminal device receives the RRC reconfiguration information from the third communication device.

[0372] Optionally, the RRC reconfiguration information includes configuration information of the candidate primary cell group for each candidate communication device in at least one candidate communication device, and at least one count value corresponding to the candidate primary cell group for each candidate communication device.

[0373] Optionally, the RRC reconfiguration information may also include at least one second identifier and / or at least one random access resource corresponding to the configuration of at least one candidate primary cell group of at least one candidate communication device in step 702 above.

[0374] It should be understood that a detailed example of step 704 can be found above. Figure 5 Step 505 in the middle, Figure 6 Step 605 in the process.

[0375] 705, the third communication device sends fourth information to the terminal device. Correspondingly, the terminal device receives the fourth information from the third communication device.

[0376] The fourth information includes at least one NCC, which corresponds to the configuration of a candidate primary cell group for at least one candidate communication device. Taking the first NCC corresponding to the configuration of a candidate primary cell group for a first communication device as an example, assuming the first communication device corresponds to a candidate primary cell group, and this candidate primary cell group corresponds to the first NCC in the fourth information, the first NCC is used to determine the master station key corresponding to the configuration of the candidate primary cell group for the first communication device.

[0377] Optionally, the fourth information also includes at least one count value corresponding to the configuration of at least one candidate primary cell group for each candidate communication device.

[0378] It should be understood that the fourth piece of information in step 705 is equivalent to Figure 5 Information #1 in step 507 Figure 6 The information in step 607 is #1. For details, please refer to the above. Figure 5 and Figure 6 The description in the text.

[0379] 706, the third communication device sends a handover command to the terminal device. Correspondingly, the terminal device receives the handover command from the third communication device.

[0380] The handover command is used to indicate the identifier of the target primary cell group for the terminal device's handover.

[0381] It should be understood that a detailed example of step 706 can be found above. Figure 5 Step 508, Figure 6 Step 610 in the above. For detailed information, please refer to the above. Figure 5 and Figure 6 The description in the text.

[0382] Next, we will consider the two scenarios and discuss them separately. Figure 7 The following steps will be introduced:

[0383] Scenario 1:

[0384] 707, the third communication device sends first information to the first communication device. Correspondingly, the first communication device receives the first information from the third communication device.

[0385] It should be understood that, assuming the first communication device is the target master station for the terminal device to be switched to from the at least one candidate communication device determined by the third communication device, and the target master cell group for the terminal device to be switched to belongs to the candidate master cell group of the first communication device, the third communication device sends first information to the first communication device, the first information being used to indicate that the serving master station of the terminal device will switch to the first communication device, or the first information being used to indicate the candidate configuration identifier corresponding to the target master cell group for which the terminal device will switch, and the target master cell group belongs to the candidate master cell group of the first communication device.

[0386] Optionally, the first information includes the master station key corresponding to the configuration of the candidate master cell group of the first communication device.

[0387] It should also be understood that, assuming the first information does not include the master station key corresponding to the configuration of the candidate master cell group of the first communication device, the third communication device can send it to the first communication device through other signaling. The sending of the master station key by the third communication device to the first communication device and the sending of the first information by the third communication device can be performed simultaneously or sequentially, and this application does not limit this.

[0388] It should be understood that there is no specific order of execution between steps 707 and 706. A specific example of step 707 can be found above. Figure 5 Step 509 in the process.

[0389] 708, the first communication device sends a first auxiliary station key to the second communication device. Correspondingly, the second communication device receives the first auxiliary station key from the first communication device.

[0390] In one possible implementation, it is assumed that the configuration of the target primary cell group for the terminal device to be switched corresponds to a count value (e.g., a first count value). After receiving the primary station key, the first communication device determines a first secondary station key based on the first count value and sends the first secondary station key to the second communication device.

[0391] In another possible implementation, it is assumed that the target primary cell group configuration for the terminal device handover corresponds to multiple count values, wherein the multiple count values ​​include a first count value, and the first count value is the first unused count value among the multiple count values. After receiving the primary station key, the first communication device determines a first secondary station key based on the first count value and sends the first secondary station key to the second communication device.

[0392] Optionally, the first auxiliary station key in step 708 can be transmitted in the SN reconfiguration completion information.

[0393] It should be understood that a specific example of step 708 can be found above. Figure 5 Step 510 in the process.

[0394] 709. The terminal device accesses the target primary cell group corresponding to the first communication device.

[0395] It should be understood that after receiving the handover command from the third communication device in step 706, the terminal device can calculate and deduce the master station key corresponding to the configuration of the target primary cell group of the first communication device based on the NCC corresponding to the target primary cell group of the first communication device stored locally in the fourth information, according to the handover command. The terminal device then accesses the target primary cell group of the first communication device based on the master station key and conducts secure communication with the first communication device.

[0396] It should be understood that a specific example of step 709 can be found above. Figure 5 Step 511 in the process.

[0397] 710, The terminal device connects to the second communication device.

[0398] It should be understood that after the terminal device accesses the target primary cell group of the first communication device, the terminal device can communicate with the second communication device according to the auxiliary station key determined in step 709, so that even when the target primary station of the terminal device is switched to the first communication device, the terminal device and the second communication device can still communicate and maintain high-speed data transmission.

[0399] Scenario 2:

[0400] 711, the third communication device sends the master station key corresponding to the configuration of the candidate master cell group of the first communication device to the first communication device, and the third communication device sends the master station key corresponding to the configuration of the candidate master cell group of the fourth communication device to the fourth communication device.

[0401] Accordingly, the first communication device receives the master station key corresponding to the configuration of the candidate primary cell group of the first communication device, sent by the third communication device. The fourth communication device receives the master station key corresponding to the configuration of the candidate primary cell group of the fourth communication device, sent by the third communication device.

[0402] It should be understood that the master station key corresponding to the configuration of the candidate master cell group of the first communication device can be carried in the first information, similar to step 707 above.

[0403] It should also be understood that there is no specific order of execution between steps 711 and 706. A specific example of step 711 can be found above. Figure 6 Step 608 in the process.

[0404] 712, the first communication device sends auxiliary station key #1 to the second communication device, and the fourth communication device sends auxiliary station key #2 to the second communication device. Correspondingly, the second communication device receives auxiliary station key #1 from the first communication device, and the second communication device receives auxiliary station key #2 from the first communication device.

[0405] It should be understood that the auxiliary station key #1 received by the second communication device is associated with the identifier of the candidate primary cell group of the first communication device and / or the candidate configuration identifier of the candidate primary cell group, and the auxiliary station key #2 is associated with the identifier of the candidate primary cell group of the fourth communication device and / or the candidate configuration identifier of the candidate primary cell group.

[0406] It should also be understood that a specific example of step 712 can be found above. Figure 6 In step 609, the first communication device may be the one described above. Figure 6 MN2 in the above, the second communication device can be the one described above. Figure 6 In the SN, the fourth communication device can be the one described above. Figure 6 MN3 in.

[0407] 713, The terminal device accesses the candidate primary cell group corresponding to the first communication device.

[0408] It should be understood that it is assumed that the target primary cell group for the terminal device's handover belongs to the candidate primary cell group of the first communication device. After receiving the handover command from the third communication device in step 706, the terminal device calculates and infers the master station key corresponding to the configuration of the target primary cell group of the first communication device based on the NCC corresponding to the target primary cell group of the first communication device stored locally in the fourth information, according to the handover command. The terminal device accesses the target primary cell group of the first communication device according to the calculated and inferred master station key used for communication with the first communication device, and conducts secure communication with the first communication device.

[0409] It should be understood that a specific example of step 713 can be found above. Figure 6 Step 612 in the process.

[0410] 714, the first communication device sends a secondary station reconfiguration completion message to the second communication device. Correspondingly, the second communication device receives the secondary station reconfiguration completion message from the first communication device.

[0411] Optionally, the secondary station reconfiguration completion information includes the identifier of the target cell group and / or the candidate configuration identifier of the target cell group. For example, the identifier of the target primary cell group belongs to the identifier of the candidate primary cell group of the first communication device, and the candidate configuration identifier of the target primary cell group belongs to the candidate configuration identifier of the candidate primary cell group of the first communication device.

[0412] It should be understood that the identifier of the target primary cell group and / or the candidate configuration identifier of the target primary cell group can be transmitted via separate signaling, without needing to complete information retransmission through secondary station reconfiguration. Step 714 is an optional step.

[0413] 715, The terminal device connects to the second communication device.

[0414] It should be understood that after the terminal device accesses the target primary cell group of the first communication device, the terminal device communicates with the second communication device according to the auxiliary station key corresponding to the configuration of the target primary cell group of the first communication device. This enables the terminal device to still communicate with the second communication device and maintain high-speed data transmission even when the target primary station of the terminal device is switched to the first communication device.

[0415] It should also be understood that the method by which the second communication device selects the auxiliary station key corresponding to the configuration of the target primary cell group from multiple auxiliary station keys can be found in the detailed description of methods 1 to 4 in step 614 above.

[0416] Based on the above Figure 7The method shown enables the terminal device to obtain the updated auxiliary station key in a timely and accurate manner, ensuring normal communication between the terminal device and the auxiliary station, even when the primary station providing services to the terminal device has been switched and the auxiliary station remains unchanged, in subsequent handover scenarios.

[0417] It should be understood that the methods provided in the embodiments of this application can all be applied to a CU-DU separated architecture. Figure 5 For example, MN1 can be split into CU1 and DU1, MN2 into CU2 and DU2, MN3 into CU3 and DU3, and SN into CU and DU. The Xn interface for communication between MN and MN / SN corresponds to the interface between CU and CU, meaning that the information exchange between MN1, MN2, MN3, and SN corresponds to communication between CU and CU. For example, steps 501, 502, 503, 504, 509, 510, 511, 512, etc. In step 506, the terminal device reports the measurement report to DU1 of MN1, and DU1 determines the target master station for the terminal device handover based on the measurement report. In step 507, information #1 can be sent from CU1 to DU1, and then from DU1 to the terminal device. In step 508, the handover command can be sent from DU1 of MN1 to the terminal device. Similarly, in step 513, information #3 can be sent from CU2 of MN2 to DU2, and then from DU2 to the terminal device. In step 514, the switching command can be sent from DU2 of MN2 to the terminal device.

[0418] It should be understood that the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0419] It should also be understood that, in the various embodiments of this application, unless otherwise specified or in case of logical conflict, the terms and / or descriptions between different embodiments are consistent and can be referenced by each other, and the technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.

[0420] It should also be understood that the above embodiments are mainly illustrated using devices in existing network architectures as examples. It should be understood that the specific form of the device is not limited in the embodiments of this application. For example, any device that can achieve the same function in the future is applicable to the embodiments of this application.

[0421] It is understood that, in the above-described method embodiments, the methods and operations implemented by devices (such as the first communication device and the second communication device) can also be implemented by components (such as chips or circuits) that can be used in the devices.

[0422] It is also understood that some optional features in the various embodiments of this application may not depend on other features in some scenarios, or may be combined with other features in some scenarios, without limitation.

[0423] The above, combined with Figures 3 to 7 The communication method provided in the embodiments of this application is described in detail. The above-described communication method is mainly introduced from the perspective of a first communication device (e.g., MN2), a second communication device (e.g., SN), a third communication device (e.g., MN1), and a terminal device. It is understood that, in order to achieve the above functions, the first communication device, the second communication device, the third communication device, and the terminal device include hardware structures and / or software modules corresponding to the execution of each function.

[0424] Those skilled in the art will recognize that, based on the units and algorithm steps described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is implemented in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0425] The following, combined with Figures 8 to 10 This application provides a detailed description of the communication device provided in its embodiments. It should be understood that the descriptions of the device embodiments correspond to the descriptions of the method embodiments; therefore, any content not described in detail can be found in the above method embodiments. For brevity, some content is omitted.

[0426] This application embodiment can divide the transmitting or receiving device into functional modules according to the above method examples. For example, each function can be divided into its own functional modules, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division; other division methods may be used in actual implementation. The following description uses the division of functional modules according to each function as an example.

[0427] Figure 8 This is a schematic block diagram of a communication device 10 provided in an embodiment of this application. The device 10 includes a transceiver module 11 and a processing module 12. The transceiver module 11 can implement corresponding communication functions, and the processing module 12 is used for data processing. In other words, the transceiver module 11 is used to perform operations related to receiving and sending, while the processing module 12 is used to perform other operations besides receiving and sending. The transceiver module 11 can also be referred to as a communication interface or a communication unit.

[0428] Optionally, the device 10 may further include a storage module 13, which can be used to store instructions and / or data. The processing module 12 can read the instructions and / or data in the storage module to enable the device to perform the operation of the device in the aforementioned method embodiments.

[0429] In one design, the device 10 may correspond to the first communication device in the above method embodiments, or to a component of the first communication device (such as a chip).

[0430] The device 10 can implement the steps or processes corresponding to those performed by the first communication device in the above method embodiment. The transceiver module 11 can be used to perform the transceiver-related operations of the first communication device in the above method embodiment, and the processing module 12 can be used to perform the processing-related operations of the first communication device in the above method embodiment.

[0431] In one possible implementation, transceiver module 11 is used to send an add request information to the second communication device; transceiver module 11 is also used to receive add request confirmation information from the second communication device; after receiving the add request confirmation information, transceiver module 11 is also used to receive a master station key corresponding to the configuration of the candidate cell group of the first communication device; processing module 12 is used to send a first auxiliary station key to the second communication device through transceiver module 11 according to the master station key, wherein the first communication device is the target master station for terminal device handover, the second communication device is an auxiliary station providing services to the terminal device, and the candidate cell group includes a candidate master cell group.

[0432] When the device 10 is used to perform Figure 5 In the method described above, the first communication device is MN2, the transceiver module 11 can be used to perform the steps of sending and receiving information in the method, such as steps 501, 502, 503, 504, 509, 510, and 511, and the processing module 12 can be used to perform the processing steps in the method.

[0433] When the device 10 is used to perform Figure 6 When the method is used, the first communication device is MN2, the transceiver module 11 can be used to perform the steps of sending and receiving information in the method, such as steps 601, 602, 603, 604, 608, 609, 611, 612, 615, 616, 618 and 619, and the processing module 12 can be used to perform the processing steps in the method.

[0434] When the device 10 is used to perform Figure 7When the method is in use, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, such as steps 701, 702, 703, 707, 708, 709, 711, 712, 713 and 714, and the processing module 12 can be used to execute the processing steps in the method.

[0435] It should be understood that the specific process of each unit performing the above-mentioned corresponding steps has been described in detail in the above method embodiments, and will not be repeated here for the sake of brevity.

[0436] In another design, the device 10 may correspond to the second communication device in the above method embodiment, or to a component of the second communication device (such as a chip).

[0437] The device 10 can implement the steps or processes corresponding to those performed by the second communication device in the above method embodiments. The transceiver module 11 can be used to perform transceiver-related operations of the second communication device in the above method embodiments, and the processing module 12 can be used to perform processing-related operations of the second communication device in the above method embodiments.

[0438] In one possible implementation, transceiver module 11 is configured to receive at least one add request information from at least one candidate communication device; transceiver module 11 is further configured to send at least one add request confirmation information to at least one candidate communication device; after transceiver module 11 sends the at least one add request confirmation information, transceiver module 11 is further configured to receive at least one auxiliary station key, the at least one auxiliary station key corresponding to the configuration of at least one candidate cell group of at least one candidate communication device, the at least one candidate cell group including at least one candidate primary cell group, wherein at least one candidate communication device includes a first communication device, the first communication device being the target primary station for terminal device handover, and at least one auxiliary station key including a first auxiliary station key, the first auxiliary station key being used for communication between a second communication device and the terminal device when the terminal device accesses the target primary cell group, the target primary cell group belonging to the candidate primary cell group of the first communication device, and the second communication device being an auxiliary station providing services to the terminal device.

[0439] When the device 10 is used to perform Figure 5 In the method described above, the second communication device is an SN, the transceiver module 11 can be used to perform the steps of sending and receiving information in the method, such as steps 502, 503, 510 and 516, and the processing module 12 can be used to perform the processing steps in the method.

[0440] When the device 10 is used to perform Figure 6When the method is used, the second communication device is an SN, the transceiver module 11 can be used to perform the steps of sending and receiving information in the method, such as steps 602, 603, 609, 613, 617, 621 and 622, and the processing module 12 can be used to perform the processing steps in the method.

[0441] When the device 10 is used to perform Figure 7 When the method is in use, the transceiver module 11 can be used to execute the steps of sending and receiving information in the method, such as steps 701, 702, 708, 712, 714 and 715, and the processing module 12 can be used to execute the processing steps in the method.

[0442] In one design, the device 10 may correspond to the terminal device in the above method embodiments, or a component of the terminal device (such as a chip).

[0443] The device 10 can implement the steps or processes corresponding to those executed by the terminal device in the above method embodiments. The transceiver module 11 can be used to perform transceiver-related operations of the terminal device in the above method embodiments, and the processing module 12 can be used to perform processing-related operations of the terminal device in the above method embodiments.

[0444] In one possible implementation, transceiver module 11 is used to receive Radio Resource Control (RRC) reconfiguration information from a third communication device;

[0445] After receiving the RRC reconfiguration information, the transceiver module 11 is further configured to receive fourth information from the third communication device. The fourth information includes at least one next-hop chain calculation NCC, which corresponds to the configuration of a candidate cell group for at least one candidate communication device. The first NCC in the at least one NCC is used to determine the master station key corresponding to the configuration of the candidate cell group for the first communication device. The at least one candidate communication device includes the first communication device, and the candidate cell group includes a candidate master cell group. The first communication device is the target master station for terminal device handover, and the third communication device is the source master station providing services to the terminal device. The fourth information also includes at least one count value corresponding to the configuration of the candidate cell group for each of the at least one candidate communication device. The RRC reconfiguration information includes the configuration information of the candidate cell group for each candidate communication device and at least one count value corresponding to the configuration information of the candidate cell group.

[0446] It should be understood that the specific process of each unit performing the above-mentioned corresponding steps has been described in detail in the above method embodiments, and will not be repeated here for the sake of brevity.

[0447] It should also be understood that the device 10 here is embodied in the form of a functional module. The term "module" here can refer to application-specific integrated circuits (ASICs), electronic circuits, processors (e.g., shared processors, proprietary processors, or group processors, etc.) and memories for executing one or more software or firmware programs, integrated logic circuits, and / or other suitable components supporting the described functions. In an alternative example, those skilled in the art will understand that device 10 may specifically be a mobility management network element in the above embodiments, and may be used to execute the various processes and / or steps corresponding to the mobility management network element in the above method embodiments; or, device 10 may specifically be a terminal device in the above embodiments, and may be used to execute the various processes and / or steps corresponding to the terminal device in the above method embodiments. To avoid repetition, further details are omitted here.

[0448] The apparatus 10 of each of the above-described schemes has the function of implementing the corresponding steps performed by the devices (such as the first communication device, the second communication device, the third communication device, and the terminal device) in the above-described methods. This function can be implemented by hardware or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-described functions; for example, the transceiver module can be replaced by a transceiver (for example, the transmitting unit in the transceiver module can be replaced by a transmitter, and the receiving unit in the transceiver module can be replaced by a receiver), and other units, such as processing modules, can be replaced by processors, which respectively execute the transceiver operations and related processing operations in each method embodiment.

[0449] In addition, the transceiver module 11 can also be a transceiver circuit (for example, it may include a receiving circuit and a transmitting circuit), and the processing module can be a processing circuit.

[0450] Figure 9 This is a schematic diagram of another communication device 20 provided in an embodiment of this application. The device 20 includes a processor 21, which is used to execute computer programs or instructions stored in a memory 22, or to read data / signaling stored in the memory 22, to perform the methods in the above-described method embodiments. Optionally, there may be one or more processors 21.

[0451] Optionally, such as Figure 9 As shown, the device 20 also includes a memory 22 for storing computer programs or instructions and / or data. The memory 22 may be integrated with the processor 21 or may be disposed separately. Optionally, there may be one or more memories 22.

[0452] Optionally, such as Figure 9As shown, the device 20 also includes a transceiver 23 for receiving and / or transmitting signals. For example, the processor 21 controls the transceiver 23 to receive and / or transmit signals.

[0453] As one option, the device 20 is used to implement the operations performed by the first communication device or the second communication device in the various method embodiments described above.

[0454] It should be understood that the processor mentioned in the embodiments of this application can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor can be a microprocessor or any conventional processor.

[0455] It should also be understood that the memory mentioned in the embodiments of this application can be volatile memory and / or non-volatile memory. Non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. Volatile memory can be random access memory (RAM). For example, RAM can be used as an external cache. By way of example and not limitation, RAM includes the following forms: static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (SLDRAM), and direct rambus RAM (DR RAM).

[0456] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA, or other programmable logic device, discrete gate or transistor logic device, or discrete hardware component, the memory (storage module) can be integrated into the processor.

[0457] It should also be noted that the memory described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0458] Figure 10 This is a schematic diagram of a chip system 30 provided in an embodiment of this application. The chip system 30 (or processing system) includes logic circuitry 31 and an input / output interface 32.

[0459] The logic circuit 31 can be a processing circuit in the chip system 30. The logic circuit 31 can be coupled to a memory unit, calling instructions from the memory unit, enabling the chip system 30 to implement the methods and functions of the embodiments of this application. The input / output interface 32 can be an input / output circuit in the chip system 30, outputting processed information from the chip system 30, or inputting data or signaling information to be processed into the chip system 30 for processing.

[0460] As one option, the chip system 30 is used to implement the operations performed by the first communication device or the second communication device in the various method embodiments described above.

[0461] For example, logic circuit 31 is used to implement processing-related operations performed by the first communication device or the second communication device in the above method embodiments; input / output interface 32 is used to implement sending and / or receiving-related operations performed by the terminal device in the above method embodiments.

[0462] This application also provides a computer-readable storage medium storing computer instructions for implementing the methods executed by the device in the above-described method embodiments.

[0463] For example, when the computer program is executed by a computer, the computer can implement the methods executed by the first communication device, the second communication device, the third communication device, and the terminal device in the various embodiments of the above methods.

[0464] This application also provides a computer program product comprising instructions which, when executed by a computer, implement the methods performed by the first communication device, the second communication device, the third communication device, and the terminal device in the above-described method embodiments.

[0465] This application also provides a communication system, including the aforementioned first communication device, second communication device and third communication device.

[0466] The explanations and beneficial effects of the relevant contents in any of the devices provided above can be found in the corresponding method embodiments provided above, and will not be repeated here.

[0467] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0468] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0469] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0470] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0471] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0472] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0473] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication method characterized by comprising: The method comprises: sending first addition request information to a second communication device; receiving first addition request confirmation information of the second communication device; after receiving the first addition request confirmation information, receiving a master station key corresponding to a configuration of a candidate cell group of the first communication device; sending a first secondary station key to the second communication device according to the master station key, wherein the first communication device is a target master station of terminal device switching, the second communication device is a secondary station providing service for the terminal device, and the candidate cell group comprises a candidate master cell group.

2. The method of claim 1, wherein, After receiving the addition request confirmation information, the method further comprises: receiving first information for indicating that a service master station of the terminal device will switch to the first communication device, the first information comprising the master station key.

3. The method according to claim 1 or 2, characterized in that, The sending of the first secondary station key to the second communication device according to the master station key comprises: sending the first secondary station key to the second communication device according to the received master station key.

4. The method according to any one of claims 1 to 3, characterized in that, The first addition request information comprises one or more of the following information: information indicating that the first communication device is a candidate communication device of terminal device switching, information indicating that the first communication device is a candidate communication device of subsequent switching of the terminal device, or information indicating that the first communication device is a candidate communication device of cross-base station or cross-centralized unit switching of the terminal device.

5. The method according to any one of claims 1 to 4, characterized in that, The sending of the first secondary station key to the second communication device according to the master station key comprises: determining the first secondary station key according to the master station key and a first count value; sending the first secondary station key to the second communication device, wherein the first count value corresponds to a target master cell group to be accessed by the terminal device, and the target master cell group belongs to the candidate master cell group of the first communication device.

6. The method according to any one of claims 1 to 4, characterized in that, The sending of the first secondary station key to the second communication device according to the master station key comprises: determining the first secondary station key according to the master station key and a first unused count value in a plurality of count values; sending the first secondary station key to the second communication device, wherein the first count value corresponds to a target cell group to be accessed by the terminal device, and the target cell group belongs to the candidate master cell group of the first communication device.

7. The method of claim 6, wherein, Before the receiving of the master station key corresponding to the configuration of the candidate cell group of the first communication device, the method further comprises: sending switching request confirmation information to a third communication device, the switching request confirmation information comprising configuration information of a candidate cell group corresponding to the first communication device and the plurality of count values, wherein the third communication device is a source master station providing service for the terminal device.

8. The method according to any one of claims 5 to 7, characterized in that, The sending of the first secondary station key to the second communication device comprises: sending secondary station reconfiguration completion information to the second communication device, the secondary station reconfiguration completion information comprising the first secondary station key.

9. A communication method characterized by comprising: The method comprises: receiving at least one addition request information of at least one candidate communication device; sending at least one addition request confirmation information to at least one candidate communication device; after sending the at least one adding request confirmation information, receiving at least one secondary station key corresponding to a configuration of at least one candidate cell group of at least one candidate communication device, the at least one candidate cell group comprising at least one candidate primary cell group, wherein the at least one candidate communication device comprises a first communication device, the first communication device being a target primary station of a terminal device handover, the at least one secondary station key comprising a first secondary station key, the first secondary station key being used for communication between a second communication device and the terminal device in a case that the terminal device accesses a target primary cell group, the target primary cell group belonging to a candidate primary cell group of the first communication device, the second communication device being a secondary station serving the terminal device.

10. The method of claim 9, wherein, the at least one adding request information comprises a first adding request information, the first adding request information comprising one or more of the following information: information indicating that the first communication device is a candidate communication device of a terminal device handover, information indicating that the first communication device is a candidate communication device of a subsequent handover of the terminal device, or information indicating that the first communication device is a candidate communication device of a cross-base station or cross-centralized unit handover of the terminal device, in a case that the first adding request information further comprises a second secondary station key, the method further comprises: ignoring the second secondary station key.

11. The method according to claim 9 or 10, characterized in that, in a case that a plurality of secondary station keys of a plurality of candidate communication devices are received, the method further comprises: receiving second information from the first communication device, the second information comprising an identity of the target primary cell group and / or a candidate configuration identity corresponding to the target primary cell group, the identity of the target primary cell group and / or the candidate configuration identity corresponding to the target primary cell group corresponding to the first secondary station key; selecting the first secondary station key from the plurality of secondary station keys according to the second information; communicating with the terminal device according to the first secondary station key, wherein the target primary cell group is a primary cell group to be accessed by the terminal device.

12. The method of claim 9 or 10, wherein, in a case that a plurality of secondary station keys of a plurality of candidate communication devices are received, the method further comprises: receiving third information from the terminal device, the third information comprising an identity of the target primary cell group and / or a candidate configuration identity corresponding to the target primary cell group, the third information being information transmitted in a random access procedure of the terminal device, the identity of the target primary cell group and / or the candidate configuration identity corresponding to the target primary cell group corresponding to the first secondary station key; selecting the first secondary station key from the plurality of secondary station keys according to the third information; communicating with the terminal device according to the first secondary station key, wherein the target primary cell group is a primary cell group to be accessed by the terminal device.

13. The method of claim 9 or 10, wherein, a first adding request confirmation information of the at least one adding request confirmation information comprises a first identity and / or a first random access resource, the first identity and / or the first random access resource corresponding to a configuration of the target primary cell group.

14. The method of claim 13, wherein, After receiving the plurality of secondary station keys of the plurality of candidate communication apparatuses, the method further comprises: In a random access procedure of the terminal device, receiving a first identifier from the terminal device, selecting the first secondary station key corresponding to the configuration of the target master cell group from the plurality of secondary station keys according to the first identifier, and / or selecting the first secondary station key corresponding to the configuration of the target master cell group from the plurality of secondary station keys according to a random access resource used by the terminal device, Wherein, the random access resource includes a random access preamble and / or a random access occasion indication.

15. The method according to any one of claims 11 to 14, characterized in that, After selecting the first secondary station key from the plurality of secondary station keys, the method further comprises: Deleting the secondary station keys other than the first secondary station key from the plurality of secondary station keys.

16. A method of communication, comprising: Comprise: Receiving at least one handover request confirmation information from at least one candidate communication apparatus, the at least one candidate communication apparatus including the first communication apparatus, the first handover request confirmation information in the at least one handover request confirmation information including configuration information of a candidate cell group of the first communication apparatus and at least one count value corresponding to the configuration of the candidate cell group of the first communication apparatus, the candidate cell group including a candidate master cell group, After receiving the at least one handover request confirmation information, sending a radio resource control (RRC) reconfiguration information to the terminal device; After sending the RRC reconfiguration information to the terminal device, sending fourth information to the terminal device, the fourth information including at least one next hop chain calculation (NCC), the at least one NCC corresponding to the configuration of the candidate cell group of at least one candidate communication apparatus, a first NCC in the at least one NCC being used to determine a master station key corresponding to the configuration of the candidate cell group of the first communication apparatus, the fourth information further including at least one count value corresponding to the configuration of the candidate cell group of each candidate communication apparatus, Wherein, the first communication apparatus is the target master station of the handover of the terminal device.

17. A method of communication, comprising: Comprise: Receiving a radio resource control (RRC) reconfiguration information from a third communication apparatus; After receiving the RRC reconfiguration information, receiving fourth information from the third communication apparatus, the fourth information including at least one next hop chain calculation (NCC), the at least one NCC corresponding to the configuration of the candidate cell group of at least one candidate communication apparatus, a first NCC in the at least one NCC being used to determine a master station key corresponding to the configuration of the candidate cell group of the first communication apparatus, the at least one candidate communication apparatus including the first communication apparatus, the candidate cell group including a candidate master cell group, The first communication device is a target master station for terminal device switching, the third communication device is a source master station providing service for the terminal device, the fourth information further includes at least one counting value corresponding to the configuration of the candidate cell group of each candidate communication device in the at least one candidate communication device, and the RRC reconfiguration information includes configuration information of the candidate cell group of each candidate communication device and at least one counting value corresponding to the configuration information of the candidate cell group.

18. The method of claim 17, wherein, The method further includes: determining a first secondary station key according to the master station key and a first counting value in the at least one counting value, the first counting value corresponding to the configuration of the candidate cell group of the first communication device; communicating with a second communication device according to the first secondary station key, wherein the second communication device is a secondary station providing service for the terminal device.

19. The method of claim 18, wherein, In a case where the configuration of the candidate cell group of the first communication device corresponds to multiple counting values, the first counting value is a first unused counting value in the multiple counting values.

20. The method of any one of claims 17-19, wherein, The RRC reconfiguration information further includes at least one second identifier and / or at least one random access resource, the at least one second identifier and / or the at least one random access resource corresponding to the configuration of at least one candidate cell group of each candidate communication device.

21. The method of claim 20, wherein, In a process in which the terminal device initiates random access to the second communication device, the method further includes: sending a first identifier in the at least one second identifier to the second communication device, the first identifier being used to determine a first secondary station key from multiple secondary station keys; and / or, initiating random access using a first random access resource in the at least one random access resource, the first random access resource being used to determine the first secondary station key from the multiple secondary station keys, wherein the multiple secondary station keys correspond to the configuration of the candidate cell group of each candidate communication device, and the multiple candidate communication devices include the first communication device, and the first secondary station key corresponds to the configuration of the candidate cell group of the first communication device.

22. A communications device, characterized by The apparatus includes a processor coupled with a memory, the memory being configured to store computer programs or instructions, and the processor being configured to execute the computer programs or instructions in the memory, so that the apparatus performs the method of any one of claims 1 to 21.

23. A computer-readable storage medium, characterized in that, The computer readable storage medium stores computer programs or instructions, which, when executed on a computer, cause the computer to perform the method of any one of claims 1 to 21.

24. A chip system, characterized by The chip system includes a processor configured to call and run computer programs from a memory, so that a communication device installed with the chip system performs the method of any one of claims 1 to 21.

25. A computer program product, characterised in that, The computer program product, when executed on a computer, causes the computer to perform the method of any one of claims 1 to 21.

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