Communication method and communication apparatus

Abstract

A communication method and a communication apparatus. The method comprises: a first communication apparatus sending first addition request information to a second communication apparatus, wherein the second communication apparatus is a secondary node that provides services for a terminal device; receiving first addition request acknowledgement information from the second communication apparatus; after the first addition request acknowledgement information is received, receiving a master node key corresponding to a candidate master cell group configuration of the first communication apparatus; and after the master node key is received, on the basis of the master node key, sending a first secondary node key to the second communication apparatus. When a serving master node for a terminal device is handed over to a first communication apparatus and a second communication apparatus remains unchanged, the second communication apparatus can promptly and accurately obtain a secondary node key used when the first communication apparatus provides services for the terminal device, so as to ensure that the terminal device after handover still adopts a DC architecture, thereby maintaining the high-speed data transmission, and thus ensuring the user experience.

Description

Communication method and communication apparatus

[0001] The present application claims priority to the Chinese patent application No. 202411398050.X, filed on September 30, 2024, and entitled "Communication method and communication apparatus", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of wireless communication, and more particularly, to a communication method and a communication apparatus. BACKGROUND

[0003] In a mobile communication system, due to the movement of a terminal, the communication link between the terminal and the access network device changes, and the terminal device may perform cell switching or access network device switching. When the terminal device switches from a source access network device to a target access network device, key update needs to be performed.

[0004] In a dual connection (DC) network architecture, a terminal device can connect two network devices, referred to as a master node (MN) and a secondary node (SN), respectively. The MN can also be referred to as a master node or a master station, and the SN can also be referred to as a secondary node or a secondary station. In a scenario where the MN performs access network device switching and the SN does not perform switching, the master station key between the MN and the terminal device is updated, and since the secondary station key is determined based on the master station key, the secondary station key also needs to be updated.

[0005] In a subsequent switching scenario, assuming that the MN performs switching and the SN does not perform switching, how to accurately and timely update the secondary station key is a hot research topic at present. SUMMARY

[0006] The present application provides a communication method, in a subsequent switching scenario, the service master station has performed switching, and the secondary station has not performed switching, so as to enable the secondary station to obtain the updated secondary station key in a timely manner, ensure terminal device data transmission, and improve user experience.

[0007] In a first aspect, a communication method is provided, which can be executed by a first communication apparatus, or can also be executed by a component (such as a chip or a circuit) of the first communication apparatus, and the present application does not limit this. Hereinafter, the first communication apparatus is taken as an example to introduce the method.

[0008] The method can comprise: sending first addition request information to the 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; and 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.

[0009] Optionally, the candidate cell group can further comprise a candidate secondary cell group.

[0010] It should be understood that the candidate master cell group comprises one master cell. Optionally, the candidate master cell group can further comprise one or more secondary cells.

[0011] According to the method provided in the present application, after the first communication device receives the master station key, the first communication device sends a first secondary station key to the second communication device according to the master station key, wherein the first secondary station key is determined according to the master station key. In the case that the service master station of the terminal device switches to the first communication device and the second communication device remains, the second communication device can timely and accurately obtain the secondary station key in the case that the first communication device provides service for the terminal device, thereby ensuring that the terminal device after switching still uses the DC architecture, maintaining the transmission of high-speed data, and guaranteeing the user experience.

[0012] In combination with the first aspect, in some possible implementation manners, after receiving the first addition request confirmation information, the method further comprises: receiving first information, wherein the first information is used to indicate that the service master station of the terminal device will switch to the first communication device.

[0013] Optionally, the first information can be further used to indicate a candidate configuration identifier corresponding to a target master cell group to which the terminal device will switch, wherein the target master cell group belongs to the candidate master cell group of the first communication device.

[0014] In combination with the first aspect, in some possible implementation manners, the first information comprises the master station key.

[0015] It should be understood that the master station key received by the first communication device can be transmitted through first information, wherein the first information is used to indicate that the service master station of the terminal device switches to the first communication device.

[0016] In combination with the first aspect, in some possible implementation manners, 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 reception of the master station key.

[0017] It should be understood that the first communication device sends the first secondary station key to the second communication device, which can be understood as that the first communication device determines the first secondary station key according to the master station key and sends the first secondary station key to the second communication device under the trigger of receiving the master station key by the first communication device.

[0018] In combination with the first aspect, in some possible implementation manners, 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 for terminal device switching, information indicating that the first communication device is a candidate communication device for subsequent switching of the terminal device, or information indicating that the first communication device is a candidate communication device for cross-base station or cross-cluster unit switching of the terminal device.

[0019] In combination with the first aspect, in some possible implementation manners, 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, and 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 a candidate master cell group of the first communication device.

[0020] It should be understood that the count value in the present application can be referred to as sk-counter or sn-counter.

[0021] It should be understood that the first communication device in the present application corresponds to at least one candidate master cell group, and the at least one candidate master cell group comprises one master cell. The candidate master cell group can further comprise one or more secondary cells. The candidate master cell group comprises a target master cell.

[0022] In combination with the first aspect, in some possible implementation manners, 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, and 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 a candidate master cell group of the first communication device.

[0023] It should be understood that the terminal device is about to access one of the at least one candidate master cell group of the first communication device, which can be referred to as a target master cell group. The target master cell group is configured to correspond to a plurality of count values, and the first communication device determines the first secondary station key by using a first unused count value in the plurality of count values and the master station key.

[0024] It should also be understood that the target master cell group belongs to a candidate master cell group of a target master station for the terminal device to switch to, i.e., the target master cell group includes one master cell. Assuming that the target master cell group further includes one or more secondary cells, in the case that the terminal device accesses the target master cell group, the terminal device accesses all the cells included in the target master cell group.

[0025] In combination with the first aspect, in some possible implementation manners, before the receiving of the master station key corresponding to the configuration of the candidate master cell group of the first communication device, the method further includes: sending, to a third communication device, switching request confirmation information, the switching 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 serving the terminal device.

[0026] In combination with the first aspect, in some possible implementation manners, the sending of the first secondary station key to the second communication device includes: sending, to the second communication device, secondary station reconfiguration completion information, the secondary station reconfiguration completion information including the first secondary station key.

[0027] It should be understood that when the first communication device sends the first secondary station key to the second communication device, the first secondary station key can be carried in secondary station reconfiguration completion information of the first communication device, thereby saving signaling overhead of the first communication device.

[0028] In combination with the first aspect, in some possible implementation manners, the method further includes: sending, to the second communication device, second information, the second information including an identifier of a target master cell group and / or a candidate configuration identifier corresponding to the target master cell group, the identifier of the target master cell group and the candidate configuration identifier corresponding to the target master cell group corresponding to the first secondary station key, the target master cell group being a master cell group that the terminal device is about to access, the target master cell group belonging to a candidate master cell group of the first communication device.

[0029] It should be understood that the first communication device can further send, to the second communication device, second information, the identifier of the target master cell group and / or the candidate configuration identifier corresponding to the target master cell group in the second information can facilitate the second communication device to select the first secondary station key corresponding to the configuration of the target master cell group from a plurality of received secondary station keys (e.g., the first secondary station key, the second secondary station key, the third secondary station key, and the like), for communication between the second communication device and the terminal device in the case that the first communication device serves the terminal device, i.e., in the case that the terminal device accesses the target master cell group, thereby ensuring normal data transmission of the terminal device.

[0030] It should also be understood that the first secondary station key of the application can also be understood as being used for security processing in a communication process between the second communication device and the terminal device.

[0031] In a second aspect, a communication method is provided, which can be executed by the second communication device, or can also be executed by a component (such as a chip or a circuit) of the second communication device, and the application does not limit this. Hereinafter, the method will be introduced taking the second communication device as an example.

[0032] 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 the at least one candidate communication device; after sending the at least one addition request confirmation information, receiving at least one secondary station key, the at least one secondary station key corresponding to a configuration of at least one candidate cell group of the at least one candidate communication device, the at least one candidate cell group comprising at least one candidate cell group, wherein the at least one candidate communication comprises a first communication device, the first communication device being a target primary station of a terminal device switching, the at least one secondary station key comprising a first secondary station key, the first secondary station key being used for communication between the second communication device and the terminal device in a case where 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, and the second communication device being a secondary station providing a service for the terminal device.

[0033] It should be understood that the at least one addition request information corresponds to a configuration of a candidate primary cell group of the at least one candidate communication device. The configuration of the candidate primary cell group of one of the at least one candidate communication device corresponds to the at least one addition request information, respectively.

[0034] According to the method provided by the application, after the second communication device sends the at least one addition request confirmation information, the second communication device receives the at least one secondary station key. The at least one secondary station key comprises the first secondary station key corresponding to the configuration of the target primary cell group. In a case where the service primary station of the terminal device switches to the first communication device and the second communication device remains, the second communication device can obtain the first secondary station key corresponding to the target primary cell group in time and accurately, thereby ensuring that the terminal device after switching still uses the DC architecture, maintaining the high-speed data transmission process, and guaranteeing the user experience.

[0035] In addition, 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 master cell group of the at least one candidate communication device, which is determined by the at least one candidate communication device upon receiving the trigger of the master station key, and sent to the second communication device. Thus, the second communication device can obtain the secondary station key before the service master station of the terminal device is switched, so as to ensure that the communication process between the terminal device and the secondary station can be resumed as soon as possible when the terminal device is subsequently switched to the master station, and the user experience is ensured.

[0036] In combination with the second aspect, in some possible implementation manners, the at least one addition request information includes first addition request information, and the first addition request information includes one or more of the following information: information indicating that the first communication device is a candidate communication device for switching of the terminal device, information indicating that the first communication device is a candidate communication device for subsequent switching of the terminal device, or information indicating that the first communication device is a candidate communication device for cross-base station or cross-centralized unit switching of the terminal device. In the case where the first addition request information further includes a second secondary station key, the method further includes: ignoring the second secondary station key.

[0037] It should be understood that, taking the first addition request information in the at least one addition request information as an example, assuming that the first addition request information includes one or more of the following information: information indicating that the first communication device is a candidate communication device for switching of the terminal device, information indicating that the first communication device is a candidate communication device for subsequent switching of the terminal device, or information indicating that the first communication device is a candidate communication device for cross-base station or cross-centralized unit switching of the terminal device, and the first addition request information further includes a second secondary station key, the second communication device ignores the second secondary station key.

[0038] It should also be understood that, assuming that the second addition request information in the at least one addition request information does not include any one or more of the above-mentioned indication information, and the second addition request information includes a second secondary station key, the second communication device can store the second secondary station key locally for subsequent communication with the terminal device.

[0039] In some possible implementation manners, in the case that the second communication device receives a plurality of secondary station keys of the plurality of candidate communication devices, the method further includes: receiving second information from the first communication device, the second information including an identification of the target master cell group and / or a candidate configuration identification corresponding to the target master cell group, the identification of the target master cell group and / or the candidate configuration identification corresponding to the target master 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; and performing communication with the terminal device according to the first secondary station key, wherein the target master cell group is a master cell group to be accessed by the terminal device.

[0040] It should be understood that the plurality of secondary station keys received by the second communication device are respectively associated with the identification of the plurality of candidate master cell groups and / or the candidate configuration identification of the plurality of candidate master cell groups. The plurality of candidate master cell groups includes the target master cell group.

[0041] It should be understood that, assuming that the second communication device receives a plurality of secondary station keys, the second communication device can select a secondary station key (for example, 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 second information of the first communication device.

[0042] In some possible implementation manners, in the case that the second communication device receives a plurality of secondary station keys of the plurality of candidate communication devices, the method further includes: receiving third information from the terminal device, the third information including an identification of the target master cell group and / or a candidate configuration identification corresponding to the target master cell group, the third information being information transmitted in a random access process of the terminal device, the identification of the target master cell group and / or the candidate configuration identification corresponding to the target master cell 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; and performing communication with the terminal device according to the first secondary station key, wherein the target master cell group is a master cell group to be accessed by the terminal device.

[0043] It should be understood that, assuming that the second communication device receives a plurality of secondary station keys, the second communication device can select a secondary station key (for example, 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 third information of the terminal device.

[0044] In some possible implementation manners, the first addition request confirmation information of the at least one addition request confirmation information includes a first identification and / or a first random access resource, the first identification and / or the first random access resource corresponding to the target cell group configuration.

[0045] It should be understood that the random access resource in the present application refers to a random access resource of a target master cell group corresponding secondary cell group.

[0046] With reference to the second aspect, in some possible implementation manners, after receiving the plurality of secondary station keys of the plurality of candidate communication devices, the method further includes: receiving a first identifier from the terminal device in a random access process of 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.

[0047] With reference to the second aspect, in some possible implementation manners, the random access resource includes a random access preamble and / or a random access occasion indication.

[0048] With reference to the second aspect, in some possible implementation manners, after selecting the first secondary station key from the plurality of secondary station keys, the method further includes: deleting secondary station keys other than the first secondary station key in the plurality of secondary station keys.

[0049] The third aspect provides a communication method, which can be executed by a third communication device or a component (for example, a chip or a circuit) of the third communication device, and the present application does not limit the third communication device. Optionally, the third communication device can be a source master station serving a terminal device. The method is described below by taking the third communication device as an example.

[0050] The method includes the following steps: receiving at least one handover request confirmation information from at least one candidate communication device, the at least one candidate communication device including the first communication device, a 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 device and 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 master cell group; after receiving the at least one handover request confirmation information, sending radio resource control (RRC) reconfiguration information to a terminal device; and 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 chaining count (NCC), the at least one NCC corresponding to the configuration of the candidate cell group of the at least one candidate communication device, and 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 device, wherein the first communication device is a target master station of the terminal device.

[0051] It should be understood that the third aspect corresponds to the above-mentioned first aspect and second aspect, and the specific description and technical effects can refer to the description of the above-mentioned first aspect and second aspect.

[0052] In combination with the third aspect, in some possible implementation manners, 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.

[0053] It should be understood that the third communication device sends the fourth information including at least one counting value to the terminal device, so that the terminal device can obtain the secondary station key between the terminal device and the secondary station in time in the case that the terminal device switches the service primary station, and ensure the data transmission between the terminal device and the secondary station.

[0054] In combination with the third aspect, in some possible implementation manners, after the fourth information is sent, the method further includes:

[0055] sending first information to the first communication device, the first information being used for indicating that the service primary station of the terminal device will switch to the first communication device.

[0056] In combination with the third aspect, in some possible implementation manners, the first information includes the primary station key.

[0057] In combination with the third aspect, in some possible implementation manners, the method further includes:

[0058] sending at least one primary station key to the at least one candidate communication device, the at least one primary 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 primary station key including the primary station key.

[0059] The fourth aspect provides a communication method, which can be executed by a terminal device, or can also be executed by a component (for example, a chip or a circuit) of the terminal device, and the present application does not limit this. Hereinafter, the method is introduced by taking the terminal device as an example.

[0060] The method includes: receiving radio resource control (RRC) reconfiguration information from a third communication device;

[0061] receiving, after receiving the RRC reconfiguration information, fourth information from the third communication device, the fourth information comprising at least one next hop chaining count (NCC), the at least one NCC corresponding to configuration of a candidate cell group of at least one candidate communication device, a first NCC of the at least one NCC being used to determine a master key corresponding to configuration of a candidate cell group of the first communication device, the at least one candidate communication device comprising the first communication device, the candidate cell group comprising a candidate master cell group,

[0062] wherein the first communication device is a target master for terminal device handover, the third communication device is a source master serving the terminal device, and the RRC reconfiguration information comprises 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.

[0063] It should be understood that the configuration information of the candidate cell group comprises configuration information of a candidate master cell group.

[0064] It should also be understood that the fourth aspect corresponds to the first aspect to the third aspect described above, and the detailed description can refer to the description of the first aspect to the third aspect.

[0065] In combination with the fourth aspect, in some possible implementation manners, the fourth information further comprises at least one count value corresponding to the configuration of the candidate cell group of each candidate communication device in the at least one candidate communication device.

[0066] In combination with the fourth aspect, in some possible implementation manners, the method further comprises: determining a first secondary key according to the master key and a first count value of 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 according to the first secondary key, wherein the second communication device is a secondary serving the terminal device.

[0067] In combination with the fourth aspect, in some possible implementation manners, in a case where the configuration of the candidate master cell group of the first communication device corresponds to a plurality of count values, the first count value is a first unused count value of the plurality of count values.

[0068] In combination with the fourth aspect, in some possible implementation manners, before the communicating with the second communication device according to the first secondary key, the method further comprises: receiving handover command information from the third communication device, the handover command being used to indicate an identity of a target master cell group for the terminal device handover.

[0069] In some possible implementation manners, in combination with the fourth aspect, the RRC reconfiguration information further comprises 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 each candidate cell group of each candidate communication device.

[0070] It should be understood that the at least one second identifier is an identifier used by the terminal device when applying the configuration of the candidate cell group corresponding to the second identifier. For example, the identifier included in the at least one second identifier can be a cell-radio network temporary identifier (C-RNTI). Each second identifier corresponds to one candidate cell group, for example, a first identifier in the at least one second identifier corresponds to a target cell group, and the target cell group belongs to the candidate cell group of the first communication device.

[0071] In some possible implementation manners, in combination with the fourth aspect, in the process in which the terminal device initiates random access to the second communication device, the method further comprises:

[0072] sending, to the second communication device, a first identifier in the at least one second identifier, the first identifier being used to determine a first secondary station key from a plurality of 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 plurality of secondary station keys, wherein the plurality of secondary station keys correspond to the configuration of the candidate primary cell group of each candidate communication device, the plurality of candidate communication devices including the first communication device, and the first secondary station key corresponds to the configuration of the candidate primary cell group of the first communication device.

[0073] It should be understood that the secondary station key corresponding to the configuration of the candidate primary cell group can be understood as that, when the terminal device accesses the candidate primary cell, the terminal device can use the secondary station key corresponding to the configuration of the candidate primary cell group to communicate with the secondary station.

[0074] In a fifth aspect, a communication device is provided, which is configured to execute the method provided in the first aspect. Specifically, the communication device can include units and / or modules for executing the method provided in any of the implementation manners of the first aspect, such as a processing unit and an obtaining unit.

[0075] In an implementation manner, the transceiver unit can be a transceiver, or the 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.

[0076] In an implementation form, the transceiving unit can be a transceiver, or an input / output interface; and the processing unit can be at least one processor. Optionally, the transceiver can be a transceiving circuit. Optionally, the input / output interface can be an input / output circuit.

[0077] In a sixth aspect, a communication apparatus is provided, which is configured to perform the method of the second aspect. Specifically, the communication apparatus can include units and / or modules for performing the method of the second aspect, such as a processing unit and an obtaining unit.

[0078] In an implementation form, the transceiving unit can be a transceiver, or an input / output interface; and the processing unit can be at least one processor. Optionally, the transceiver can be a transceiving circuit. Optionally, the input / output interface can be an input / output circuit.

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

[0080] In a seventh aspect, a communication apparatus is provided, which is configured to perform the method of the third aspect. Specifically, the communication apparatus can include units and / or modules for performing the method of the third aspect, such as a processing unit and an obtaining unit.

[0081] In an implementation form, the transceiving unit can be a transceiver, or an input / output interface; and the processing unit can be at least one processor. Optionally, the transceiver can be a transceiving circuit. Optionally, the input / output interface can be an input / output circuit.

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

[0083] In an eighth aspect, a communication apparatus is provided, which is configured to perform the method of the fourth aspect. Specifically, the communication apparatus can include units and / or modules for performing the method of the fourth aspect, such as a processing unit and an obtaining unit.

[0084] In an implementation form, the transceiving unit can be a transceiver, or an input / output interface; and the processing unit can be at least one processor. Optionally, the transceiver can be a transceiving circuit. Optionally, the input / output interface can be an input / output circuit.

[0085] In another implementation, the transceiving unit can be an input / output interface, interface circuit, output circuit, input circuit, pin or related circuit, etc. on the chip, chip system or circuit; and the processing unit can be at least one processor, processing circuit or logic circuit, etc.

[0086] In a ninth aspect, a processor is provided for executing the method provided in any of the implementation manners of the first to fourth aspects.

[0087] For the sending and obtaining / receiving operations of the processor, if no special description is provided, or if it does not contradict the actual role or inherent logic in the related description, it can be understood as the processor outputting and receiving, inputting, etc. operations, or as the sending and receiving operations performed by the radio frequency circuit and the antenna, which are not limited in the present application.

[0088] In a tenth aspect, a computer readable storage medium is provided, which stores program codes for execution by a device, and the program codes include codes for executing the method provided in any of the implementation manners of the first to fourth aspects.

[0089] In an eleventh aspect, a computer program product containing instructions is provided, which, when executed on a computer, causes the computer to execute the method provided in any of the implementation manners of the first to fourth aspects.

[0090] In a twelfth aspect, a chip is provided, which includes a processor and a communication interface, and the processor reads instructions stored on a memory through the communication interface and executes the method provided in any of the implementation manners of the first to fourth aspects.

[0091] Optionally, as an implementation manner, the chip further includes a memory, and the memory stores a computer program or instructions, and the processor is configured to execute the computer program or instructions stored on the memory, and when the computer program or instructions are executed, the processor is configured to execute the method provided in any of the implementation manners of the first to fourth aspects.

[0092] In a thirteenth aspect, a communication system is provided, which includes the first communication device, a second communication device and a third communication device. BRIEF DESCRIPTION OF DRAWINGS

[0093] FIG. 1 is a schematic diagram of a network architecture to which the embodiments of the present application are applicable.

[0094] FIG. 2 is a schematic diagram of a dual connectivity network architecture to which the embodiments of the present application are applicable.

[0095] FIG. 3 is a schematic flowchart of a communication method provided by the embodiments of the present application.

[0096] FIG. 4 is a schematic flow chart of another communication method according to an embodiment of the present application.

[0097] FIG. 5 is a schematic flow chart of another communication method according to an embodiment of the present application.

[0098] FIG. 6 is a schematic flow chart of another communication method according to an embodiment of the present application.

[0099] FIG. 7 is a schematic flow chart of another communication method according to an embodiment of the present application.

[0100] FIG. 8 is a schematic diagram of a communication apparatus according to an embodiment of the present application.

[0101] FIG. 9 is a schematic diagram of another communication apparatus according to an embodiment of the present application.

[0102] FIG. 10 is a schematic diagram of a chip system according to an embodiment of the present application. DETAILED DESCRIPTION

[0103] In order to facilitate understanding of the embodiments of the present application, the following points are first explained.

[0104] First, in the present application, "for indicating" can include for directly indicating and for indirectly indicating. When describing that certain indication information is for indicating A, it can include that the indication information directly indicates A or indirectly indicates A, and does not mean that A must be carried in the indication information.

[0105] The information indicated by the indication information is referred to as to-be-indicated information, and there are many ways to indicate the to-be-indicated information in the specific implementation process. For example, but not limited to, the to-be-indicated information can be directly indicated, such as the to-be-indicated information itself or an index of the to-be-indicated information. The to-be-indicated information can also be indirectly indicated by indicating other information, where the other information and the to-be-indicated information have an association relationship. The to-be-indicated information can also be only indicated in part, and the other part of the to-be-indicated information is known or agreed in advance. For example, the indication of a specific information can also be achieved by means of the arrangement order of each information agreed in advance (for example, a protocol stipulates), thereby reducing the indication overhead to a certain extent. At the same time, the common part of each information can be identified and uniformly indicated, so as to reduce the indication overhead caused by separately indicating the same information.

[0106] Second, "at least one" in the present application means one or more, and "multiple" means two or more. In addition, in the embodiments of the present application, "first", "second", and various numbers (for example, "#1", "#2", and the like) are only used for the convenience of description and do not limit the scope of the embodiments of the present application. The size of the serial number of each process below does not mean the order of execution, and the execution order of each process should be determined according to its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present application. It should be understood that the objects thus described can be interchanged under appropriate circumstances, so as to be able to describe solutions other than the embodiments of the present application. In addition, in the embodiments of the present application, "S210" and the like are only labels used for the convenience of description and do not limit the order of execution steps.

[0107] Third, in the embodiments of the present application, "exemplary" or "for example" and the like are used to indicate an example, illustration or description. Any embodiment or design scheme described as "exemplary" or "for example" in the present application should not be interpreted as more preferred or more advantageous than other embodiments or design schemes. Rather, the use of "exemplary" or "for example" and the like is intended to present the relevant concept in a specific manner.

[0108] Fourth, in the embodiments of the present application, "saving" can mean saving in one or more memories. The one or more memories can be separately provided or integrated in the encoder or decoder, processor, or communication device. The one or more memories can be partially separately provided and partially integrated in the decoder, processor, or communication device. The type of memory can be any form of storage medium, which is not limited in the present application.

[0109] Fifth, in the embodiments of the present application, "protocol" can refer to a standard protocol in the communication field, which can include NR protocol and related protocols applied to future communication systems, which is not limited in the present application.

[0110] Sixth, in the embodiments of the present application, "of", "corresponding", "corresponding", and "associated" can be used interchangeably at times, and it should be pointed out that their meanings are consistent when their differences are not emphasized.

[0111] Seventh, in the embodiments of the present application, "in the case of", "when", "if" can be used interchangeably at times, and it should be pointed out that their meanings are consistent when their differences are not emphasized.

[0112] Eighth, the term "and / or" in this text is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B can represent: A exists alone, A and B exist together, and B exists alone. In addition, the character " / " in this text generally represents that the front and rear associated objects are in an "or" relationship.

[0113] The technical solutions in the application will be described below with reference to the drawings.

[0114] The communication method provided by the application can be applied to various communication systems, for example, it can be an internet of things (IoT), narrow band internet of things (NB-IoT), long term evolution (LTE), or a 5th generation (5G) communication system, or a hybrid architecture of LTE and 5G, or a 5G new radio (NR) system, or a future communication network, or a new communication system that will appear in future communication development, etc. The communication system described in the application can also be a machine to machine (M2M) network or other network.

[0115] FIG. 1 shows a schematic diagram of a communication system to which the embodiments of the application are applied. In the 5G system, the 5G access point is composed of the base station node next generation radio access network (NG-RAN), and the NG-RAN node can be a 5G new base station node (gNB) or an LTE evolved base station node (ng-eNB). Among them, the gNB uses the user plane and control plane protocol stack of NR, and the ng-eNB uses the user plane and control plane protocol stack of evolved universal terrestrial radio access (E-UTRA) except for the service data adaptation protocol (SDAP) layer.

[0116] The gNBs and gNBs, ng-eNBs and ng-eNBs, gNBs and ng-eNBs are interconnected through an Xn interface. The gNBs and ng-eNBs are connected to a 5G core (5GC) device through an NG interface. For example, the control plane is connected to a core network device (such as an access and mobility management function (AMF)) through an NG-C interface, and the user plane is connected to a core network device (such as a user plane function (UPF)) through an NG-U interface.

[0117] It should be understood that FIG. 1 is only an example and does not constitute any limitation on the protection scope of the present application. The scenario shown in FIG. 1 can also include other devices, such as terminal devices, servers, and the like. For example, the 5GC also includes other functional network elements in addition to the AMF and the APF.

[0118] The terminal equipment in the embodiments of the present application can refer to an access terminal, a subscriber unit, a subscriber station, a mobile station, a mobile station, a relay station, a remote station, a remote terminal, a mobile device, a user terminal (user terminal), a user equipment (user equipment, UE), a terminal, a wireless communication device, a user agent, or a user device. The terminal equipment can also be a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication function, a computing device, or other processing devices connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a 5G network, or a terminal device in a future evolved public land mobile network (PLMN), and the like. The embodiments of the present application are not limited thereto.

[0119] By way of example and not limitation, in embodiments of the present application, the wearable device can also be referred to as a smart wearable device, which is a general term for devices that can be worn on the body, such as glasses, gloves, watches, clothing, and shoes, and the like, which are designed and developed by applying wearable technology to daily wear. The wearable device is a portable device that can be worn directly on the body or integrated into the user's clothes or accessories. The wearable device is not only a hardware device, but also a powerful function achieved through software support and data interaction, cloud interaction. Broadly, the smart wearable device includes a full function, large size, and can realize complete or partial functions without relying on a smart phone, such as a smart watch or smart glasses, and focuses on a certain application function and needs to be used with other devices, such as a smart phone, such as various smart wristbands, smart jewelry, and the like, which monitor vital signs.

[0120] In addition, in embodiments of the present application, the terminal device can also be a terminal device in an IoT system, which is mainly characterized by connecting objects to the network through communication technology, thereby realizing the intelligent network of man-machine interconnection and object-object interconnection. In embodiments of the present application, IoT technology can achieve massive connection, deep coverage, and terminal power saving through, for example, narrow band (NB) technology.

[0121] For example, the terminal device can be a terminal device in an XR scenario such as a VR terminal, an AR terminal, or an MR terminal; for another example, the terminal device can be a wireless terminal in industrial control, a wireless terminal in self driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, and the like. The terminal device here refers to a 3GPP terminal. Embodiments of the present application do not limit the type or category of the terminal device. For ease of illustration, embodiments of the present application will be described hereinafter by taking a UE as an example to represent the terminal device.

[0122] The base station in the embodiments of the present application can be any kind of device with wireless transceiving function for communicating with the terminal device. The device 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 NodeB (HeNB, or home Node B, HNB), baseband unit (BBU), access point (AP) in a wireless fidelity (WIFI) system, wireless relay node, wireless backhaul node, transmission point (TP), or transmission and reception point (TRP), etc., and can also be gNB or transmission point (TRP or TP) in a 5G, such as NR, system, one or a group (including multiple antenna panels) of antenna panels of the base station in the 5G system, or a network node constituting the gNB or transmission point, such as baseband unit (BBU), or distributed unit (DU), etc., and can also be a device for communicating with the terminal device in a future communication network, such as gNB in the future communication network.

[0123] In some deployments, a gNB can include a centralized unit (CU) and a DU. The gNB can also include an active antenna unit (AAU). The CU implements part of the functions of the gNB, and the DU implements part of the functions of the gNB. For example, the CU is responsible for processing non-real-time protocols and services, implementing the radio resource control (RRC), and the functions of the packet data convergence protocol (PDCP) layer. The DU is responsible for processing the physical layer protocol and real-time services, implementing the functions of the radio link control (RLC) layer, the media access control (MAC) layer, and the physical (PHY) layer. The AAU implements part of the physical layer processing functions, radio frequency processing, and related functions of the active antenna. Since the information of the RRC layer eventually becomes the information of the PHY layer, or is transformed from the information of the PHY layer, under this architecture, high-layer signaling, such as RRC layer signaling, can also be considered as being sent by the DU, or by the DU+AAU. It can be understood that the access network device can be a device including one or more of the CU node, the DU node, and the AAU node. In addition, the CU can be divided into a network device in the radio access network (RAN), or can be divided into a network device in the core network (CN), which is not limited in the present application.

[0124] In different systems, the CU (or CU-CP and CU-UP), DU, or RU can also have different names, but those skilled in the art can understand their meanings. For example, the radio access network can also be an open radio access network (O-RAN) architecture, in which the CU can also be referred to as an O-CU (open CU), the DU can also be referred to as an O-DU, the CU-CP can also be referred to as an O-CU-CP, the CU-UP can also be referred to as an O-CU-UP, and the RU can also be referred to as an O-RU. Any of the CU (or CU-CP, CU-UP), DU, and RU in the present application can be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0125] The core network device part in the embodiments of the present application can 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 function (UDM), unified data repository function (UDR), network data analytics function (NWDAF), authentication server function (AUSF), AMF, session management function (SMF), network slice selection function (NSSF), and the like. Among them, the AMF, SMF, UPF, NEF, AUSF, NRF, PCF, NSSF, UDM can be understood as network elements in the core network for realizing different functions, for example, can be combined into a network slice as needed. These core network network elements can be independent devices respectively, or can be integrated into the same device to realize different functions, and the specific form of the above network elements is not limited in the present application.

[0126] It should be understood that the above naming is only defined for the purpose of distinguishing different functions, and should not constitute any limitation on the present application. The present application does not exclude the possibility of using other names in 5G networks and future other networks. For example, in future communication networks, part or all of the above network elements can use the terms in 5G, or other names, etc.

[0127] It should be understood that FIG. 1 is an example of a communication scenario to which the present application can be applied, taking the communication between the access network device and the terminal device, and the communication between the access network device and the core network device as an example, and does not limit other scenarios to which the present application can be applied. It should also be understood that FIG. 1 is a simplified schematic diagram for ease of understanding, and other network devices or other terminal devices can also be included in the communication system, which are not shown in FIG. 1.

[0128] For the convenience of understanding the embodiments of the present application, some basic concepts related to the present application are briefly described.

[0129] For the convenience of understanding the embodiments of the present application, some basic concepts related to the present application are briefly described.

[0130] 1. Dual connection (DC)

[0131] Figure 2 shows a schematic diagram of a network architecture of dual connection. In the network architecture of DC, a user equipment (UE) can connect two access network devices at the same time, which are MN and SN respectively. Taking the example that both MN and SN are new radio (NR) base stations, i.e., 5th generation (5G) communication system base stations, the network architecture of DC is shown in Figure 2, where (a) of Figure 2 is a schematic diagram of control plane architecture, and (b) of Figure 2 is a schematic diagram of user plane architecture.

[0132] The interface between MN and SN is Xn interface, and there is at least control plane connection between MN and SN, i.e., Xn-C shown in (a) of Figure 2, where C represents control plane, and there can also be user plane connection between MN and SN, i.e., Xn-U shown in (b) of Figure 2, where U represents user plane; there is NG interface between MN and core network device, and there is at least control plane connection between MN and core network device, i.e., NG-C connection between MN and access and mobility management function (AMF) shown in (a) of Figure 2, and there can also be user plane connection between MN and core network device, i.e., NG-U connection between MN and user plane function (UPF) shown in (b) of Figure 2; there can be user plane connection between SN and core network device, i.e., NG-U connection between SN and UPF shown in (b) of Figure 2.

[0133] 2. Master node key (MN key)

[0134] The master key can refer to a key used when the UE communicates with the MN. The master key can be denoted as k_gNB. Specifically, the UE and the MN can further derive a key k_UP used for user plane data security processing and a key k_RRC used for control plane signaling security processing using k_gNB. The packet data convergence protocol (PDCP) layer of the UE and the MN uses k_UP and k_RRC to perform security processing on user plane data and control plane signaling respectively. For example, the security processing can include integrity protection and encryption operations.

[0135] It should be understood that some bearers can be configured to use PDCP of MN and RLC of SN, for example, MN terminated SCG bearer, where SCG represents secondary cell group, and such bearers also use the master key for security processing. That is, the PDCP layer is in MN, and the master key is used.

[0136] 3. Secondary node key or secondary key (SN key)

[0137] The secondary key can refer to a key used when the UE communicates with the SN. The secondary key can be denoted as k_SN. Specifically, the UE and the SN use k_SN to further derive a key k_UP for security processing of user plane data and a key k_RRC for security processing of control plane signaling. The PDCP layers of the UE and the SN use k_UP and k_RRC to perform security processing on user plane data and control plane signaling, respectively.

[0138] It should be understood that some bearers can be configured to use PDCP of MN and RLC of SN, for example, MN terminated SCG bearer, where SCG represents secondary cell group, and such bearers also use the master key for security processing. That is, the PDCP layer is in MN, and the master key is used.

[0139] It should also be understood that the secondary node key can be derived based on the master node key.

[0140] In a mobile communication system, due to the movement of a terminal device, the communication link between the terminal device and an access network device changes, and the terminal device can perform cell switching or access network device switching. When the terminal device switches from a source access network device to a target access network device, key updating needs to be performed. Embodiments of the present application provide a method that can accurately update the key in a switching scenario and ensure smooth communication of the terminal device and user experience.

[0141] FIG. 3 is a schematic flowchart of a communication method according to an embodiment of the present application. As shown in FIG. 3, the method includes the following steps:

[0142] 301, MN1 sends switching request information to MN2. Correspondingly, MN2 receives the switching request information from MN1.

[0143] Wherein, MN1 is a source master node that provides services for the terminal device, and MN2 is a target master node to which the terminal device switches.

[0144] It should be understood that the handover request information includes the master key (e.g., k_gNB) determined by the MN1 for the communication between the MN2 and the terminal device. Specifically, the detailed introduction of the master key determined by the MN1 for the communication between the MN2 and the terminal device can be referred to the existing solutions, and will not be described here.

[0145] It should be further understood that the handover request information can also include the identification information of the SN, and the handover request information can be used to indicate the identity of the SN used by the terminal device to communicate in the DC architecture to the MN2.

[0146] 302, the MN2 sends SN addition request information to the SN. Correspondingly, the SN receives the addition request information from the MN2.

[0147] For example, after the MN2 receives the handover request information from the MN1, the MN2 sends the addition request information to the SN according to the handover request information.

[0148] It should be understood that after the MN2 receives the handover request information, when the MN2 determines that the SN in the DC architecture does not need to be changed, the MN2 sends the addition request information to the SN according to the identification information of the SN in the handover request information. The addition request information includes the secondary key (e.g., k_SN) used for the communication between the SN and the terminal device. Specifically, the MN2 determines the secondary key between the SN and the terminal device according to the master key in the handover request information and a counter value, which can be represented as sn-counter or sk-counter. The MN2 derives the secondary key between the SN and the terminal device according to the master key and the counter value received in step 301, and the detailed derivation process can be referred to the existing solutions, and will not be described here.

[0149] 303, the SN sends SN addition request confirmation information to the MN2. Correspondingly, the MN2 receives the addition request confirmation information from the SN.

[0150] It should be understood that the addition request confirmation information is used to reply to the addition request information in step 302.

[0151] 304, the MN2 sends handover request confirmation information to the MN1. Correspondingly, the MN1 receives the handover confirmation request information from the MN2.

[0152] It should be understood that the 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 the handover of the terminal device. Specifically, the handover request confirmation information can be used to indicate that the related information of the context of the terminal device remains in the SN.

[0153] It should be understood that the count value for deriving the secondary station key is included in the handover request acknowledgement message.

[0154] 305, the MN1 sends the SN release request information to the SN. Accordingly, the SN receives the release request information from the MN1.

[0155] It should be understood that the release request information can be used to indicate that the context related information of the terminal device is maintained in the SN.

[0156] 306, the SN sends the SN release request acknowledgement information to the MN1. Accordingly, the MN1 receives the SN release request acknowledgement information from the SN.

[0157] 307: the MN1 sends the RRC reconfiguration information to the terminal device. Accordingly, the terminal device receives the RRC reconfiguration information from the MN1.

[0158] It should be understood that the RRC reconfiguration information is used to trigger the terminal device to perform handover.

[0159] It should also be understood that the RRC reconfiguration information includes the related parameters (such as NCC) for the terminal device to determine the primary station key used for communication between the terminal device and the MN2. Accordingly, after the terminal device receives the NCC, the terminal device calculates and derives the primary station key (such as k_gNB) used for communication between the terminal device and the MN2 according to the NCC. The detailed derivation process is similar to the derivation process of the primary station key corresponding to the candidate master cell group of the MN2 determined by the MN1 in step 301, and specific details can be referred to the detailed description of the existing scheme.

[0160] It should also be understood that the RRC reconfiguration information further includes the related parameters (such as count value: sn-counter or sk-counter) for the terminal device to determine the secondary station key used for communication between the terminal device and the SN. The terminal device can further calculate and derive the secondary station key (such as k_SN) used for communication between the terminal device and the SN according to the primary station key used for communication between the terminal device and the MN2 and the count value. The detailed derivation process is similar to the derivation process in step 302, and specific details can be referred to the detailed description of the existing scheme.

[0161] 308, the terminal device accesses the MN2 through random access.

[0162] It should be understood that after the terminal device accesses the MN2, the terminal device communicates with the MN2 through the primary station key determined in step 307 between the terminal device and the MN2, so as to ensure the security of the transmission data and / or signaling in the process of communication between the terminal device and the MN2.

[0163] In the embodiments of the present application, the communication can include data transmission, signaling interaction, etc.

[0164] 309: The terminal device sends RRC reconfiguration complete information to MN2.

[0165] 310: The terminal device accesses the SN through a random access manner.

[0166] It should be understood that after the terminal device accesses the SN, the terminal device communicates with the SN through the secondary station key determined in step 307, so as to ensure the security of the transmission data and / or signaling in the process of communication between the terminal device and the SN.

[0167] It should be understood that the above Fig. 3 shows that the master station providing services for the terminal device is switched (switched from MN1 to MN2) under the DC network architecture, the SN remains unchanged, the MN1 indicates the master station key used for communication between the MN2 and the terminal device through the switching request information, the MN2 determines the corresponding secondary station key based on the master station key for communication between the MN2 and the terminal device, and sends the secondary station key to the SN, so as to ensure that the terminal device can align the secondary station key used for communication between the terminal device and the secondary station in the case that the master station is switched and the secondary station remains unchanged, thereby ensuring the smooth communication of the terminal device and the user experience.

[0168] Fig. 4 is a schematic flow chart of another communication method provided by an embodiment of the present application. As shown in Fig. 4, the method comprises the following steps:

[0169] 401: The gNB1 sends switching request information to candidate gNBs (gNB2 and gNB3). Correspondingly, the gNB2 and the gNB3 receive the switching request information from the gNB1.

[0170] It should be understood that the switching request information is used to request the candidate gNBs to provide configuration information of candidate cell groups.

[0171] It should also be understood that the gNB1 is a source network device providing services for the terminal device, and the gNB2 and the gNB3 are candidate network devices providing services for the terminal device.

[0172] 402: The candidate gNBs (gNB2 and gNB3) respectively send switching request confirmation information to the gNB1. Correspondingly, the gNB1 receives the switching request confirmation information from the gNB2 and the gNB3.

[0173] It should be understood that the handover request acknowledgement information includes configuration information of candidate cell groups of the candidate gNB, and each candidate cell group includes at least one cell. For example, the handover request acknowledgement information corresponding to the gNB2 includes configuration information of candidate cell groups of the gNB2, and the handover request acknowledgement information corresponding to the gNB3 includes configuration information of candidate cell groups of the gNB3. The embodiment shown in FIG. 4 will be exemplarily described by taking an example that the gNB2 provides the Cell2 as a candidate cell and the gNB3 provides the Cell3 as a candidate cell.

[0174] 403. The gNB1 sends RRC reconfiguration information to the terminal device. Correspondingly, the terminal device receives the RRC reconfiguration information from the gNB1.

[0175] It should be understood that the RRC reconfiguration information includes configuration information of candidate cell groups of candidate gNBs. For example, the RRC reconfiguration information includes configuration information of candidate cell groups of the gNB2 and configuration information of candidate cell groups of the gNB3.

[0176] It should be understood that the configuration information of the candidate cell group includes configuration information that should be used by the terminal device when accessing the corresponding cell (for example, the Cell2 or the Cell3), such as uplink physical channel configuration, downlink physical channel configuration, measurement configuration, bearer configuration, and the like.

[0177] 404. The gNB1 sends a handover command to the terminal device. Correspondingly, the terminal device receives the handover command from the gNB1.

[0178] It should be understood that the handover command is used to trigger the terminal device to perform handover. The terminal device performs handover according to the RRC reconfiguration information received in step 403.

[0179] It is assumed that the handover command in this step 404 indicates that the target cell of the terminal device is the Cell2, that is, the network device serving the terminal device is switched from the gNB1 to the gNB2. The terminal device switches to the Cell2 according to the handover command and based on the configuration information of the Cell2 in the RRC reconfiguration information in step 403. For example, the method shown in FIG. 4 further includes:

[0180] 405. The terminal device accesses the Cell2 of the gNB2 based on the configuration information of the Cell2.

[0181] It should be understood that after the terminal device accesses the Cell2, due to the movement of the location of the terminal device or other reasons, the terminal device needs to be switched to the Cell3 cell of the gNB3, and then the method shown in FIG. 4 can further include:

[0182] 406. The gNB2 sends a handover command to the terminal device. Correspondingly, the terminal device receives the handover command from the gNB2.

[0183] It should be understood that the switching command is used to trigger the terminal device to perform switching. Wherein, the terminal device performs switching according to the RRC reconfiguration information received in step 403.

[0184] It is assumed that the switching command in step 406 indicates that the target cell of the terminal device is Cell3, that is, the network device serving the terminal device is switched from gNB2 to gNB1. The terminal device switches to Cell3 according to the switching command based on the configuration information of Cell3 in the RRC reconfiguration information in step 403. For example, the method shown in FIG. 4 further comprises:

[0185] 407, the terminal device accesses the Cell3 of the gNB3 based on the configuration information of the Cell3.

[0186] It should be understood that the method shown in FIG. 4 described above describes that in the mobility management technology, a plurality of candidate cells are configured for the terminal device, and the terminal device can perform multiple switching in the plurality of candidate cells. For example, the terminal device is first switched from the cell Cell1 corresponding to the gNB1 to the cell Cell2 corresponding to the gNB2, and then switched from the cell Cell2 corresponding to the gNB2 to the cell Cell3 corresponding to the gNB3. The process of the terminal device performing multiple switching in the plurality of candidate cells can be referred to as a "subsequent switching" technology.

[0187] Based on the switching method of the terminal device shown in FIGS. 3 and 4 provided by the embodiments of the present application, the method shown in FIG. 3 mainly aims at single switching scene, and can realize the change of master station key and secondary station key in the scene of MN switching and SN keeping unchanged. However, in the scene of subsequent switching, the service master station corresponding to the terminal device changes multiple times, and all steps in the method shown in FIG. 3 need to be repeatedly executed, the signaling overhead between the terminal device and the network device is large, the transmission delay is large, which may cause the hysteresis of service data transmission and affect the user experience. The method shown in FIG. 4 can be applied to the "subsequent switching" technology, but cannot be applied to the DC network architecture. In each switching of the subsequent switching, the corresponding secondary station key update process is performed, which causes the terminal device and the SN to be unable to align the secondary station key, causing the communication of the terminal device to be interrupted and affecting the user experience.

[0188] In view of the problems of the above-mentioned FIGS. 3 and 4, another key update method is provided in the embodiments of the present application to solve the problems of the methods shown in FIGS. 3 and 4.

[0189] It should be understood that the method provided by the present application can be applied in the service master station switching of the terminal device and the switching scenario in which the secondary station remains, and the method provided by the present application can also be applied to other switching technologies, for example, layer 1 / layer 2 triggered mobility (LTM) switching technology, other subsequent switching technologies triggered by the access network device.

[0190] In the technology supporting the subsequent switching, the source cell / source access network device and the target cell / target access network device are a relative concept. The cell accessed by the terminal device before switching in one switching can be referred to as the source cell, and the cell accessed after switching can be referred to as the target cell. For example, when the terminal device switches from cell 1 to cell 2, cell 1 can be understood as the source cell of the present switching, and cell 2 can be understood as the target cell of the present switching. When the terminal device switches from cell 2 to cell 3, cell 2 can be understood as the source cell of the present switching, and cell 3 can be understood as the target cell of the present switching.

[0191] FIG. 5 is a flowchart of another communication method provided by an embodiment of the present application. As shown in FIG. 5, the method comprises the following steps:

[0192] 501. MN1 sends at least one switching request information to at least one candidate master station (for example, MN2 and MN3). Correspondingly, MN2 and MN3 respectively receive the switching request information sent by MN1.

[0193] It should be understood that, taking the switching request information received by MN2 as an example, the switching request information is used to request to obtain the configuration information of at least one candidate cell group of MN2. The configuration information of the at least one candidate cell group comprises the configuration information of at least one candidate master cell group.

[0194] It should also be understood that the switching request information sent by MN1 to MN2 and MN3 can be sent at the same time or sent in sequence, and the present application does not make any limitation in this regard.

[0195] 502. MN2 and MN3 respectively send SN addition request information to SN. Correspondingly, SN receives the SN addition request information from MN2 and MN3.

[0196] For example, after MN2 and MN3 receive the switching request information from MN1, the MN2 and MN3 respectively send the SN addition request information to SN according to the received switching request information.

[0197] In a possible implementation, the addition request information sent by the MN2 comprises one or more of the following indication information: information indicating that the MN2 is a candidate communication device for terminal device switching, information indicating that the MN2 is a candidate communication device for subsequent terminal device switching, or information indicating that the MN2 is a candidate communication device for terminal device cross-gNB or cross-CU switching.

[0198] In a possible implementation, the addition request information sent by the MN3 comprises one or more of the following indication information: information indicating that the MN3 is a candidate communication device for terminal device switching, information indicating that the MN3 is a candidate communication device for subsequent terminal device switching, or information indicating that the MN3 is a candidate communication device for terminal device cross-gNB or cross-CU switching.

[0199] It should be understood that the SN addition request information sent by the MN2 or the MN3 can comprise or not comprise the secondary station key indicated by the MN2 or the MN3. Assuming that the SN addition request information sent by the MN2 to the SN comprises the secondary station key, the SN receiving the SN addition request information further judges whether the SN addition request information comprises one or more of the following indication information: information indicating that the MN2 is a candidate communication device for terminal device switching, information indicating that the MN2 is a candidate communication device for subsequent terminal device switching, or information indicating that the MN2 is a candidate communication device for terminal device cross-gNB or cross-CU switching, if the SN addition request information comprises, the SN ignores the secondary station key comprised in the SN addition request information.

[0200] 503, the SN sends SN addition request confirmation information to the MN2 and the MN3 respectively. Accordingly, the MN2 and the MN3 receive the addition request confirmation information from the SN.

[0201] It should be understood that the addition request confirmation information is used to reply to the addition request information in step 502.

[0202] 504, the MN2 and the MN3 send switching request confirmation information to the MN1 respectively. Accordingly, the MN1 receives the switching confirmation request information from the MN2 and the MN3.

[0203] It should be understood that the switching 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 switching. Specifically, the switching request confirmation information can be used to indicate that the related information of the context of the terminal device is maintained in the SN.

[0204] It should be understood that the handover request acknowledgement information sent by the MN2 can include configuration information of at least one candidate cell group of the MN2 and at least one counter value (for example, sk-counter / sn-counter). The configuration of one of the at least one candidate cell group can correspond to the at least one counter value.

[0205] It is assumed that the handover request acknowledgement information sent by the MN2 to the MN1 includes configuration information of a candidate cell group provided by the MN2, wherein the handover request acknowledgement information sent by the MN2 can include a candidate configuration identifier (for example, identifier 1) corresponding to the configuration information of the candidate cell group provided by the MN2, the identifier 1 corresponding to the configuration information of the candidate cell group and at least one counter value corresponding to the configuration of the candidate cell group. It is assumed that the handover request acknowledgement information sent by the MN3 to the MN1 includes configuration information of one candidate cell group provided by the MN3, wherein the handover request acknowledgement information sent by the MN3 can include a candidate configuration identifier (for example, identifier 2) corresponding to the configuration information of the one candidate cell group provided by the MN3, the identifier 2 corresponding to the configuration information of the candidate cell group and at least one counter value corresponding to the configuration of the candidate cell group.

[0206] It should be understood that the configuration information of one candidate cell group includes configuration information of an MCG. Optionally, the configuration information of the candidate cell group can also include configuration information of a corresponding SCG. When the terminal device uses the configuration information of the candidate cell group, the configuration information of the MCG corresponding to the candidate cell group is applied, and optionally, the configuration information of the SCG corresponding to the candidate cell group can also be applied.

[0207] It should be understood that the following will be exemplarily introduced to the method provided by the present application by taking the target master cell group accessed by the terminal device as a candidate master cell group of a candidate master station (for example, the MN2 or the MN3).

[0208] 505, the MN1 sends RRC reconfiguration information to the terminal device. Correspondingly, the terminal device receives the RRC reconfiguration information from the MN1.

[0209] It should be understood that the RRC reconfiguration information includes configuration information of a candidate master cell group of at least one candidate communication device (or referred to as a candidate master station) in the above step 504. For example, the RRC reconfiguration information includes configuration information of candidate master cell groups corresponding to the MN2 and the MN3.

[0210] Optionally, the RRC reconfiguration information can further comprise at least one counting value corresponding to the configuration of at least one candidate MCG of the at least one candidate communication device. For example, the RRC reconfiguration information can further comprise at least one counting value corresponding to the configuration of at least one candidate MCG of MN2 and at least one counting value corresponding to the configuration of at least one candidate MCG of MN3.

[0211] 506, the terminal device sends the measurement result to MN1. Correspondingly, MN1 receives the measurement result from the terminal device.

[0212] It should be understood that after the terminal device receives the above-mentioned RRC reconfiguration information, the terminal device can measure the candidate MCG based on the configuration information of at least one candidate MCG in the RRC reconfiguration information and send the measurement result to MN1. The detailed process of determining the measurement result by the terminal device can refer to the existing scheme.

[0213] Optionally, the terminal device can send the measurement result to MN1 by using layer 1 (L1, physical layer).

[0214] 507, MN1 sends information #1 to the terminal device. Correspondingly, the terminal device receives information #1 from MN1.

[0215] It should be understood that after MN1 sends the RRC reconfiguration information to the terminal device, MN1 sends information #1 to the terminal device. The information #1 can also be referred to as control information, and the specific name of the information #1 is not limited.

[0216] The information #1 can comprise one or more NCCs. When the information #1 comprises one NCC, the one NCC corresponds to the configuration of all candidate MCGs. When the information #1 comprises multiple NCCs, each NCC corresponds to the configuration of a candidate MCG.

[0217] For example, the information #1 comprises one NCC, which corresponds to the configuration of the candidate MCG of MN2 and MN3. The NCC can be used by the terminal device to determine the master key for communication with the candidate MCG of MN2 and can be used by the terminal device to determine the master key for communication with the candidate MCG of MN3. It should be understood that the input parameters for deriving the master key comprise other parameters (such as cell identification information) in addition to the NCC. Therefore, even if the candidate MCGs of MN2 and MN3 share the same NCC, the master key corresponding to the candidate MCG of MN2 is different from the master key corresponding to the candidate MCG of MN3, and there is no problem of key duplication.

[0218] For example, the information #1 includes two NCCs corresponding to the candidate master cell group (e.g., the master cell group #1) of the MN2 and the candidate master cell group (e.g., the master cell group #2) of the MN3, respectively. For example, the NCC #1 corresponding to the master cell group #1 can be used for the terminal device to determine the master station key for communication with the master cell group #1; for example, the NCC #2 corresponding to the master cell group #2 can be used for the terminal device to determine the master station key for communication with the master cell group #2.

[0219] Optionally, the information #1 can further include at least one count value corresponding to the candidate master cell group configuration of the MN2 and at least one count value corresponding to the candidate master cell group configuration of the MN3. The count value can be a random value, or the count value can be a value related to the number of secondary station key updates corresponding to the SN.

[0220] It should be understood that, in the case that the RRC reconfiguration information in the step 505 does not include at least one count value corresponding to the configuration of at least one candidate master cell group of the MN2 and at least one count value corresponding to the configuration of at least one candidate master cell group of the MN3, the step 507 includes at least one count value corresponding to the configuration of at least one candidate master cell group of the MN2 and at least one count value corresponding to the configuration of at least one candidate master cell group of the MN3; in the case that the information #1 in the step 507 does not include at least one count value corresponding to the configuration of at least one candidate master cell group of the MN2 and at least one count value corresponding to the configuration of at least one candidate master cell group of the MN3, the step 505 includes at least one count value corresponding to the configuration of at least one candidate master cell group of the MN2 and at least one count value corresponding to the configuration of at least one candidate master cell group of the MN3; or, the information #1 in the step 507 and the RRC reconfiguration information in the step 505 both include at least one count value corresponding to the configuration of at least one candidate master cell group of the MN2 and at least one count value corresponding to the configuration of at least one candidate master cell group of the MN3.

[0221] It should be further understood that the information #1 can be carried in the RRC signaling, or carried in the medium access control control element (MAC CE) message, or transmitted in the downlink control information (DCI). When the information #1 is carried in the MAC CE message for transmission, the step 507 and the following step 508 can be combined into one step.

[0222] It should also be understood that after the terminal device receives the information #1, the terminal device can store the information #1 locally, and when switching to a certain candidate cell group, the terminal device performs derivation of the primary station key and the secondary station key using the NCC corresponding to the candidate cell group and the count value used for secondary station key derivation.

[0223] It should also be understood that the execution sequence between the step 506 and the step 507 is not limited.

[0224] 508, the MN1 sends a handover command to the terminal device. Accordingly, the terminal device receives the handover command from the MN1.

[0225] It should be understood that the handover command is used to indicate the identity of the target primary cell group of the terminal device switching, and the identity of the target primary cell group is the candidate configuration identity corresponding to the configuration information of a certain candidate primary cell group. The target primary cell group can be determined by the MN1 based on the measurement report in the step 506.

[0226] Assuming that the MN2 is the target primary station of the terminal device switching, the target primary cell group belongs to at least one candidate primary cell group of the MN2. For example, the at least one candidate primary cell group of the MN2 includes the primary cell group #1-1 and the primary cell group #1-2, the primary cell group #1-1 corresponds to the configuration identity 1-1, and the primary cell group #1-2 corresponds to the configuration identity 1-2. Assuming that the MN1 determines that the target primary cell group of the terminal device is the candidate primary cell group #1-1 of the MN2, the identity of the target primary cell group of the terminal device indicated by the handover command can be 1-1.

[0227] It should also be understood that the candidate primary cell group can include one primary cell (PCell) and optionally one or more secondary cells (SCell), which are not limited by the present application.

[0228] It should also be understood that the handover command can be carried in the MAC CE for transmission.

[0229] 509, the MN1 sends information #2 to the MN2. Accordingly, the MN2 receives the information #2 from the MN1.

[0230] Assuming that the MN1 determines that the target primary station of the terminal device switching is the MN2, i.e., the service primary station of the terminal device will switch from the MN1 to the MN2. Wherein, the information #2 is used to indicate that the service primary station of the terminal device will switch to the MN2, or the information #2 is used to indicate the candidate configuration identity corresponding to the target primary cell group of the terminal device switching, wherein the target primary cell group belongs to the candidate primary cell group of the MN2.

[0231] Optionally, the information #2 can comprise a master key determined by the MN1 and corresponding to a target master cell group of the MN2. The target master cell group belongs to candidate master cell groups of the MN2. The master key corresponds to a configuration of the target master cell group of the MN2.

[0232] It should be understood that the target cell group of the MN2 comprises one master cell. Optionally, the target cell group can further comprise one or more secondary cells. All the cells comprised in the target cell group of the MN2 can communicate with the terminal device through the master key, i.e. the terminal device can communicate with the cells in the target cell group of the MN2 through the master key. Assuming that the master cell and the secondary cell comprised in the carrier aggregation both belong to the target cell group of the MN2, the terminal device can communicate with the cells of the carrier aggregation through the master key.

[0233] It should be understood that the master key can also be sent to the MN2 in other signaling (e.g. cell change notification information or LTM cell change notification message). When the master key is sent to the MN2 through other separate signaling, the MN1 sending the information #2 to the MN2 can be before or after the master key is sent, and the present application does not limit the execution order.

[0234] It should be further understood that the execution order between step 508 and step 509 is not limited.

[0235] 510. The MN2 sends a secondary key #1 to the SN. Correspondingly, the SN receives the secondary key #1 of the MN2.

[0236] It should be understood that after receiving the master key sent by the MN1, the MN2 determines the secondary key (e.g. the secondary key #1) according to the master key and at least one count value corresponding to the configuration of the target master cell group. The MN2 sends the secondary key #1 to the SN, which is used for subsequent communication between the SN and the terminal device in the case that the terminal device accesses the target master cell group of the MN2.

[0237] As an example, assuming that the configuration of the target master cell group of the MN2 corresponds to one count value, the MN2 derives the secondary key #1 according to the master key corresponding to the configuration of the target master cell group of the MN2 and the count value; and assuming that the configuration of the target master cell group of the MN2 corresponds to multiple count values, the MN2 derives the secondary key #1 according to the master key corresponding to the configuration of the target master cell group and the first unused count value in the multiple count values.

[0238] Optionally, after receiving the secondary station key #1, the SN stores the secondary station key #1, instead of using the secondary station key #1 to perform PDCP establishment immediately. The SN waits until the terminal device completes the access to the SN, and then uses the secondary station key to perform PDCP re-establishment.

[0239] It should also be understood that the secondary station key #1 in step 510 can be carried in the SN reconfiguration complete information sent by the MN2 to the SN.

[0240] It should also be understood that the secondary station key #1 in step 510 can be carried in the SN modification request information (or SN modification request message).

[0241] 511, the terminal device accesses the target master cell group of the MN2.

[0242] It should be understood that after receiving the handover command from the MN1 in step 508, the terminal device can calculate the primary station key corresponding to the target master cell group configuration of the MN2 based on the NCC corresponding to the target master cell group of the MN2 stored in the information #1 by the terminal device locally, according to the handover command. The terminal device accesses the target master cell group of the MN2 according to the primary station key, and performs secure communication with the MN2.

[0243] Optionally, the terminal device determines the secondary station key between the terminal device and the SN in the case that the terminal device accesses the target master cell group, according to the primary station key corresponding to the target master cell group of the MN2 and at least one count value corresponding to the target master cell group configuration.

[0244] As an example, assuming that the target master cell group configuration corresponds to one count value, the terminal device calculates the secondary station key according to the primary station key corresponding to the target master cell group configuration and the count value; and assuming that the target master cell group configuration corresponds to multiple count values, the terminal device calculates the secondary station key according to the primary station key corresponding to the target master cell group configuration and the first unused count value in the multiple count values.

[0245] As another example, the count value used to derive the secondary station key corresponding to each candidate master cell group can be the same, in which case the information #1 received by the terminal device in step 507 can only include one count value, which corresponds to all candidate master cell groups.

[0246] 512, the terminal device accesses the SN.

[0247] It should be understood that after the terminal device accesses the target master 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 the transmission of high-speed data in the case of target master station switching of the terminal device to MN2.

[0248] It should be understood that the above steps 501 to 512 exemplarily introduce the flowchart of the service master station of the terminal device switching from MN1 to MN2, and the SN remaining unchanged. Next, steps 513 to 518 will be introduced to exemplarily introduce the flowchart of the service master station of the terminal device switching from MN2 to MN3 after the service master station of the terminal device switches from MN1 to MN2, and the SN remaining unchanged. Wherein, the terminal device performs the third and fourth master station switching, and the secondary station remains unchanged, which can be referred to the related flow of the second switching.

[0249] 513, MN2 sends information #3 to the terminal device, and correspondingly, the terminal device receives information #3 from MN2.

[0250] It should be understood that the information #3 includes one or more NCCs, when the information #3 includes one NCC, the one NCC corresponds to all candidate master cell group configurations of the candidate master station; when the information #3 includes multiple NCCs, each NCC can correspond to each candidate master cell group configuration of the candidate master station.

[0251] Suppose the candidate MN includes MN3, the information #3 includes one NCC corresponding to all candidate master cell group configurations of MN3. For example, the information #3 includes one NCC (such as NCC #3) corresponding to the candidate master cell group configuration of MN3, wherein the NCC #3 can be used for the terminal device to determine the master station key for communication with the candidate master cell group of MN3.

[0252] Wherein, the candidate MN can also include multiple MNs, such as MN3, MN4, etc., and the present application takes MN3 as an example in this example. The message #3 is similar to the message #1 sent by MN1 in the foregoing step 507, and the detailed introduction can be referred to the detailed introduction of the foregoing information #1.

[0253] It should also be understood that after the service master station of the terminal device switches from MN1 to MN2, MN2 can initiate path switching to the core network device (such as AMF gateway), and obtain the NCC value corresponding to the candidate MN from the AMF network element, and the specific process can be referred to the existing scheme, which will not be described here.

[0254] 514, MN2 sends a switching command to the terminal device. Correspondingly, the terminal device receives the switching command from MN2.

[0255] It should be understood that the handover command is used to indicate the identity of the target master cell group to which the terminal device is to be handed over. Assuming that the target master station is MN3, the identity of the target master cell group corresponds to the candidate configuration identity of the candidate master cell group of MN3. For example, the candidate master cell groups of MN3 include master cell group #2-1 and master cell group #2-2, the master cell group #2-1 corresponds to configuration identity 2-1, and the master cell group #2-2 corresponds to configuration identity 2-2. Assuming that the target master cell group corresponds to master cell group #2-1 of at least one candidate master cell group of MN3, the handover command can indicate that the identity of the target master cell group of the terminal device is 2-1.

[0256] It should be understood that step 514 is similar to step 508 described above.

[0257] 515, MN2 sends information #4 to MN3. Correspondingly, MN3 receives information #4 from MN2.

[0258] It should be understood that assuming that MN2 determines that the target master station to which the terminal device is to be handed over is MN3, i.e., the terminal device is to be handed over from MN2 to MN3. Wherein, the information #4 is used to indicate that the serving master station of the terminal device is to be handed over to MN3, or the information #4 is used to indicate the candidate configuration identity corresponding to the target master cell group to which the terminal device is to be handed over, wherein the target master cell group belongs to the candidate master cell group of MN3.

[0259] Optionally, the information #4 can include the master station key determined by MN2 corresponding to the target master cell group of MN3. Wherein, the target master cell group belongs to the candidate master cell group of MN3. The master station key corresponds to the target master cell group configuration of MN3.

[0260] It should be understood that the master station key corresponding to the target master cell group of MN3 can be carried in information #4 and sent to MN3, or sent to MN3 through other separate signaling, which is not limited by the present application. Assuming that the master station key is sent to MN3 through other separate signaling, the MN2 sending information #4 to MN3 can be before or after sending the master station key, and the present application does not limit the execution order.

[0261] It should be understood that the execution order between step 514 and step 515 is not limited.

[0262] It should also be understood that step 515 is similar to step 509 described above.

[0263] 516, MN3 sends secondary station key #2 to SN. Correspondingly, SN receives secondary station key #2 of MN3.

[0264] It should be understood that after receiving the master key sent by the MN2, the MN3 determines the secondary key (e.g., secondary key #2) according to the master key and at least one count value corresponding to the target master cell group configuration of the MN3. The MN3 sends the secondary key #2 to the SN, which is used for subsequent communication between the SN and the terminal device in the case that the terminal device accesses the target master cell group of the MN3.

[0265] As an example, assuming that the target master cell group configuration of the MN3 corresponds to one count value, the MN3 derives the secondary key #2 according to the master key corresponding to the target master cell group configuration of the MN3 and the count value. Assuming that the target master cell group configuration of the MN3 corresponds to multiple count values, the MN3 derives the secondary key #2 according to the master key corresponding to the target master cell group configuration of the MN3 and the first unused count value in the multiple count values.

[0266] Optionally, after receiving the secondary key #2, the SN stores the secondary key #2 instead of immediately using the secondary key #2 for PDCP establishment. The SN waits for the terminal device to complete the access to the SN, and then uses the secondary key for PDCP re-establishment.

[0267] It should also be understood that the secondary key #2 in the step 516 can be carried in the SN reconfiguration complete information sent by the MN3 to the SN.

[0268] It should also be understood that the secondary key #2 in the step 516 can be carried in the SN modification request information (or SN modification request message).

[0269] It should also be understood that the step 516 is similar to the step 510 described above.

[0270] 517, the terminal device accesses the target master cell group corresponding to the MN3.

[0271] It should be understood that after receiving the handover command from the MN2 in the step 514, the terminal device can derive the master key corresponding to the target master cell group configuration of the MN3 based on the NCC corresponding to the target master cell group of the MN3 stored in the information #3 locally by the terminal device. The terminal device accesses the target master cell group of the MN3 according to the master key, and performs secure communication with the MN3.

[0272] Optionally, the terminal device determines the secondary key between the terminal device and the SN in the case that the terminal device accesses the target master cell group according to the master key corresponding to the target master cell group of the MN3 and at least one count value corresponding to the target master cell group configuration.

[0273] As an example, assuming that the target master cell group configuration of the MN3 corresponds to one count value, the terminal device derives the secondary station key according to the master station key corresponding to the target master cell group configuration of the MN3 and the count value; and assuming that the target master cell group configuration of the MN3 corresponds to multiple count values, the terminal device derives the secondary station key according to the master station key corresponding to the target master cell group configuration of the MN3 and the first unused count value in the multiple count values.

[0274] As another example, the count value used for deriving the secondary station key corresponding to each candidate master cell group can be the same, in which case, the information #3 received by the terminal device in step 513 can only include one count value, which corresponds to all candidate master cell groups.

[0275] 518, the terminal device accesses the SN.

[0276] It should be understood that after the terminal device accesses the target master cell group of the 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 in the case that the target master station of the terminal device switches to the MN3.

[0277] Based on the method shown in FIG. 5, when the master station providing services for the terminal device switches under the DC network architecture, the secondary station remains unchanged, the terminal device can update the updated secondary station key in time with the secondary station, which ensures that the terminal device after switching can still use the DC architecture, maintains the high-speed data transmission process, and guarantees the user experience.

[0278] FIG. 6 is a flowchart of another key update method provided by an embodiment of the present application. As shown in FIG. 6, the method includes the following steps:

[0279] 601, the MN1 sends at least one handover request information to at least one candidate master station (for example, MN2 and MN3). Correspondingly, the MN2 and the MN3 respectively receive the handover request information sent by the MN1.

[0280] 602, the MN2 and the MN3 respectively send SN addition request information to the SN. Correspondingly, the SN receives the SN addition request information from the MN2 and the MN3.

[0281] 603, the SN sends SN addition request confirmation information to the MN2 and the MN3. Correspondingly, the MN2 and the MN3 receive the addition request confirmation information from the SN.

[0282] 604, the MN2 and the MN3 respectively send handover request confirmation messages to the MN1. Correspondingly, the MN1 receives the handover confirmation request information from the MN2 and the MN3.

[0283] 605, the MN 1 sends RRC reconfiguration information to the terminal device. Correspondingly, the terminal device receives the RRC reconfiguration information from the MN 1.

[0284] 606, the terminal device sends measurement results to the MN 1. Correspondingly, the MN 1 receives the measurement results from the terminal device.

[0285] 607, the MN 1 sends information #1 to the terminal device. Correspondingly, the terminal device receives the information #1 from the MN 1.

[0286] It should be understood that steps 601 to 607 in FIG. 6 are similar to steps 501 to 507 in FIG. 5 described above, and specific contents can be referred to the detailed description in FIG. 5 described above.

[0287] 608, the MN 1 sends information #5-1 to the MN 2 and information #5-2 to the MN 3. Correspondingly, the MN 2 receives the information #5-1 from the MN 1, and the MN 3 receives the information #5-2 from the MN 1.

[0288] It should be understood that the MN 1 determines the candidate master stations for the terminal device to switch to as the MN 2 and the MN 3, and the MN 1 can determine the master station keys corresponding to the candidate master cell group configurations of each of the candidate MNs and indicate the master station keys corresponding to the candidate master cell group configurations of each of the candidate MNs to the corresponding candidate MN. The information #5-1 includes the master station keys corresponding to the candidate master cell group configurations of the MN 2, and the information #5-2 includes the master station keys corresponding to the candidate master cell group configurations of the MN 3.

[0289] It should also be understood that the MN 1 can send the information #5-1 and the information #5-2 to the MN 2 and the MN 3 at the same time or in sequence, which is not limited in the present application.

[0290] It should also be understood that after the MN 2 receives the master station keys corresponding to the candidate master cell group configurations of the MN 2, the MN 2 does not immediately use the master station keys to communicate with the terminal device, but stores the master station keys locally in the MN 2, and when the terminal device switches to the MN 2, the MN 2 uses the master station keys to communicate with the terminal device; after the MN 3 receives the master station keys corresponding to the candidate master cell group configurations of the MN 3, the MN 3 does not immediately use the master station keys to communicate with the terminal device, but stores the master station keys locally in the MN 3, and when the terminal device switches to the MN 3, the MN 3 uses the master station keys to communicate with the terminal device.

[0291] 609, the MN 2 sends secondary station key #1 to the SN, and the MN 3 sends secondary station key #2 to the SN. Correspondingly, the SN receives the secondary station key #1 from the MN 2, and the SN receives the secondary station key #2 from the MN 3.

[0292] It should be understood that, assuming that the candidate master cell groups of MN2 and MN3 each include one master cell group, upon the triggering of step 608, MN2 sends the secondary station key #1 to the SN, and MN3 sends the secondary station key #2 to the SN, the secondary station key corresponding to the master cell group configuration. Upon receiving the secondary station key #1 and the secondary station key #2, the SN can store the secondary station key #1 and the secondary station key #2 locally. When the target master station of the terminal device is switched from MN1 to MN2 or MN3, or when the terminal device accesses the candidate master cell group corresponding to MN2 or MN3, the corresponding secondary station key is selected to communicate with the terminal device.

[0293] It should also be understood that the detailed description of MN2 determining the secondary station key #1 corresponding to the candidate master cell group of MN2 and MN3 determining the secondary station key #2 corresponding to the candidate master cell group of MN3 can be referred to the content in FIG. 5 described above.

[0294] It should also be understood that the secondary station key #1 received by the SN is associated with the identifier of the candidate master cell group of MN2 and / or the candidate configuration identifier of the candidate master cell group, and the secondary station key #2 is associated with the identifier of the candidate master cell group of MN3 and / or the candidate configuration identifier of the candidate master cell group.

[0295] 610, MN1 sends a handover command to the terminal device. Correspondingly, the terminal device receives the handover command from MN1.

[0296] It should be understood that step 610 is similar to step 508 in FIG. 5 described above.

[0297] 611, MN1 sends information #2 to MN2. Correspondingly, MN2 receives the information #2 from MN1.

[0298] Assuming that MN1 determines that the target master station to which the terminal device is to be handed over is MN2, i.e., the serving master station of the terminal device is to be switched from MN1 to MN2. The information #2 is used to indicate that the serving master station of the terminal device is to be switched to MN2, or the information #2 is used to indicate the candidate configuration identifier of the target master cell group to which the terminal device is to be handed over, wherein the target master cell group belongs to the candidate master cell group of MN2.

[0299] Alternatively, the information #2 can further include related information used to indicate the target master cell group to which the terminal device is to be handed over, wherein the target master cell group belongs to the candidate master cell group of MN2.

[0300] It should be understood that the execution sequence between step 610 and step 611 is not limited.

[0301] 612, the terminal device accesses the target master cell group corresponding to MN2.

[0302] It should be understood that after the terminal device receives the handover command from the MN1 in step 610, the terminal device can calculate and derive the master key corresponding to the target master cell group configuration of the MN2 based on the NCC corresponding to the target master cell group of the MN2 stored locally in the information #1 according to the handover command. The terminal device accesses the target master cell group of the MN2 according to the master key and performs secure communication with the MN2.

[0303] Optionally, the terminal device determines the secondary key between the terminal device and the SN in the case that the terminal device accesses the target master cell group of the MN2 according to the master key corresponding to the target master cell group of the MN2 and at least one count value corresponding to the target master cell group configuration of the MN2.

[0304] As an example, assuming that the target master cell group configuration of the MN2 corresponds to one count value, the terminal device calculates and derives the secondary key according to the master key corresponding to the target master cell group configuration of the MN2 and the count value; and assuming that the target master cell group configuration of the MN2 corresponds to multiple count values, the terminal device calculates and derives the secondary key according to the master key corresponding to the target master cell group configuration of the MN2 and the first unused count value in the multiple count values. As another example, the count value used to derive the secondary key corresponding to each candidate master cell group can be the same, in which case the information #1 received by the terminal device in step 607 can only include one count value, which corresponds to all candidate master cell groups.

[0305] 613, the MN2 sends SN reconfiguration complete information to the SN. Accordingly, the SN receives the SN reconfiguration complete information from the MN2.

[0306] Optionally, the SN reconfiguration complete information can include the identification of the target master cell group and / or the candidate configuration identification of the target master cell group. For example, the identification of the target master cell group belongs to the identification of the candidate master cell group of the MN2, and the candidate configuration identification of the target master cell group belongs to the candidate configuration identification of the candidate master cell group of the MN2.

[0307] It should be understood that the identification of the target master cell group and / or the candidate configuration identification of the target master cell group can be transmitted through separate signaling and not retransmitted in the SN reconfiguration complete information. Step 613 is an optional step.

[0308] 614, the terminal device accesses the SN.

[0309] It should be understood that after the terminal device accesses the target master cell group of the MN2, the terminal device communicates with the SN according to the determined secondary key corresponding to the target master cell group configuration of the MN2, so as to achieve that the terminal device and the SN can still communicate and maintain the transmission of high-speed data in the case that the target master station of the terminal device is handed over to the MN2.

[0310] It should also be understood that, in the case where the SN receives multiple secondary station keys, the SN can select the secondary station key corresponding to the target master cell group from the multiple secondary station keys in the following manner:

[0311] Manner 1. When the SN reconfiguration completion information in step 613 includes the identification of the target master cell group and / or the candidate configuration identification of the target master cell group, the SN can select the secondary station key for communication with the terminal device from the multiple secondary station keys (e.g., secondary station key #1 and secondary station key #2) according to the identification of the target master cell group and / or the candidate configuration identification of the target master cell group. Assuming that the serving master station of the terminal device is switched from MN1 to MN2, the identification of the target master cell group in the SN reconfiguration completion information belongs to the identification of the candidate master cell group of MN2, and the candidate configuration identification of the target master cell group belongs to the candidate configuration identification of the candidate master cell group of MN2. The SN selects secondary station key #1 corresponding to the target master cell group from secondary station key #1 and secondary station key #2 according to the identification of the target master cell group and / or the candidate configuration identification of the target master cell group, and communicates with the terminal device through secondary station key #1.

[0312] Manner 2. In the information that the terminal device accesses the SN, the terminal device indicates the identification of the target master cell group and / or the candidate configuration identification of the target master cell group in the uplink information, and the SN receives the uplink information from the terminal device and determines that the target master cell group belongs to the candidate master cell group of MN2 according to the identification of the target master cell group and / or the candidate configuration identification of the target master cell group in the uplink information. The SN selects secondary station key #1 corresponding to the target master cell group from secondary station key #1 and secondary station key #2 according to the identification of the target master cell group and / or the candidate configuration identification of the target master cell group, and communicates with the terminal device through secondary station key #1.

[0313] Manner 3. In the random access process initiated by the terminal device, the terminal device carries a first identification, which is in one-to-one correspondence with the candidate master cell group configuration. The first identification can be a cell-radio network temporary identifier (C-RNTI). In the random access process, the terminal device sends the first identification to the SN, and accordingly, the SN determines that the target master cell group belongs to the candidate master cell group of MN2 according to the first identification. The SN selects secondary station key #1 corresponding to the target master cell group from secondary station key #1 and secondary station key #2 according to the first identification, and communicates with the terminal device through secondary station key #1.

[0314] In the SN addition request acknowledge information in step 603, the SN can indicate at least one second identity to MN2 and MN3 respectively, wherein the at least one second identity comprises the first identity. MN2 and MN3 indicate the at least one second identity to the terminal device in the RRC reconfiguration information in step 605, wherein the at least one second identity is used to identify the candidate master cell group corresponding to MN2 and MN3. In the random access procedure, the terminal device sends information to the SN, wherein the information carries the first identity corresponding to the target master cell group of the target MN. Accordingly, the SN determines the secondary station key corresponding to the target master cell group according to the first identity.

[0315] In mode 4, different candidate master cell groups are configured to correspond to different random access resources. In the random access procedure, the terminal device initiates random access to the SN using the random access resource corresponding to the secondary cell group of the target master cell group. Accordingly, the SN determines that the target master station is MN2 and the target master cell group belongs to the candidate master cell group of MN2 according to the random access resource of the terminal device. The SN further selects the secondary station key #1 corresponding to the target master cell group from the secondary station key #1 and the secondary station key #2 according to the random access resource to communicate with the terminal device.

[0316] In the SN addition request acknowledge information in step 603, the SN can indicate at least one random access resource to MN2 and MN3 respectively, wherein the random access resources of the secondary cell groups corresponding to the candidate master cell groups of MN2 and MN3 are different. MN2 and MN3 indicate the random access resources to the terminal device in the RRC reconfiguration information in step 605, wherein the random access resources are used to identify the candidate master cell groups corresponding to MN2 and MN3. In the random access procedure, the terminal device sends information to the SN using the random access resource corresponding to the target master cell group. Accordingly, the SN determines the secondary station key corresponding to the target master cell group according to the random access resource used by the terminal device.

[0317] Optionally, the random access resource comprises a random access preamble and / or a random access occasion indication.

[0318] It should also be understood that after the SN selects the secondary station key corresponding to the target master cell group configuration of MN2, the SN deletes other secondary station keys stored locally in step 609. For example, the SN selects to use the secondary station key #1 to communicate with the terminal device, and then the SN deletes the secondary station key #2.

[0319] It should be understood that the steps 601 to 614 above exemplarily introduce the flowchart when the terminal device's serving master station is switched from MN1 to MN2 for the first time and the SN remains unchanged. Next, the steps 615 to 622 will be introduced exemplarily to introduce the flowchart when the terminal device's serving master station is switched from MN2 to MN3 and the SN remains unchanged. Wherein, the terminal device performs the third and fourth master station switching and the secondary station remains unchanged, which can be referred to the flowchart of the second switching above.

[0320] 615, the MN2 sends information #6 to the terminal device. Correspondingly, the terminal device receives the information #6 from the MN2.

[0321] It should be understood that the information #6 includes one or more NCCs, when the information #6 includes one NCC, the one NCC corresponds to the configuration of all candidate master cell groups of the candidate master station; when the information #6 includes multiple NCCs, each NCC in the multiple NCCs can correspond to the configuration of each candidate master cell group of the candidate master station.

[0322] It is assumed that the candidate MN includes MN3, and the information #6 includes one NCC corresponding to the configuration of all candidate master cell groups of the MN3. For example, the information #6 includes one NCC (such as NCC #3) corresponding to the configuration of the candidate master cell group of the MN3, and the NCC #3 can be used by the terminal device to determine the master station key for communication with the candidate master cell group of the MN3.

[0323] Wherein, the candidate MN can also include multiple MNs, such as MN3, MN4, and the like, and the present application takes the MN3 as an example for introduction in this example. The message #6 is similar to the message #1 sent by the MN1 in the step 607 above, and the detailed introduction can be referred to the detailed introduction of the message #1 above.

[0324] 616, the MN2 sends information #7 to the MN3. Correspondingly, the MN3 receives the information #7 from the MN2.

[0325] It should be understood that the MN2 determines the candidate master station of the terminal device switching as the MN3, and the 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. It is assumed that the candidate MN includes MN3, and the message #7 includes the master station key corresponding to the candidate master cell group configuration of the MN3.

[0326] 617, the MN3 sends the secondary station key #3 to the SN. Correspondingly, the SN receives the secondary station key #3 from the MN3.

[0327] It should be understood that the MN 3 sends the secondary station key #3 to the SN under the triggering of the step 616. The SN receives the secondary station key #3 and stores the secondary station key #3 locally. When the target master station of the terminal device is switched to the MN 3 by the MN 2, and the target master cell group accessed by the terminal device belongs to the candidate master cell group of the MN 3, the SN selects the secondary station key corresponding to the target master cell group to communicate with the terminal device.

[0328] It is assumed that the candidate master cell group corresponding to the MN 3 includes multiple candidate master cell groups, for example, candidate master cell group #3-1, candidate master cell group #3-2 and candidate master cell group #3-3, wherein the secondary station key corresponding to the candidate master cell group #3-1 determined by the MN 3 is the secondary station key #3-1, the secondary station key corresponding to the candidate master cell group #3-2 is the secondary station key #3-2, and the secondary station key corresponding to the candidate master cell group #3-3 is the secondary station key #3-3. When the SN receives the secondary station key #3-1, the secondary station key #3-2 and the secondary station key #3-3 from the MN 3, the SN stores the secondary station key #3-1, the secondary station key #3-2 and the secondary station key #3-3 locally, and when the terminal device accesses the candidate master cell group #3-2 of the MN 3, the SN selects the secondary station key #3-2 to communicate with the terminal device.

[0329] 618, the MN 2 sends a handover command to the terminal device. Accordingly, the terminal device receives the handover command from the MN 2.

[0330] It should be understood that the step 618 is similar to the step 610 described above.

[0331] 619, the MN 2 sends information #8 to the MN 3. Accordingly, the MN 3 receives the information #8 from the MN 2.

[0332] It should be understood that it is assumed that the MN 2 determines that the target master station to which the terminal device is to be handed over is the MN 3, i.e., the service master station of the terminal device is to be switched from the MN 2 to the MN 3. The information #8 is used to indicate that the service master station of the terminal device is to be switched to the MN 3.

[0333] Alternatively, the information #8 can further include related information indicating the target master cell group to which the terminal device is to be handed over, the target master cell group belonging to the candidate master cell group of the MN 3, or the information #8 is used to indicate the candidate configuration identifier corresponding to the target master cell group to which the terminal device is to be handed over, wherein the target master cell group belongs to the candidate master cell group of the MN 3.

[0334] It should be understood that the steps 618 and 619 are not limited in the order of execution.

[0335] 620, the terminal device accesses the target master cell group corresponding to the MN 3.

[0336] It should be understood that the terminal device accesses the target master cell group of MN3, and the target master cell group belongs to the candidate master cell group of MN3. The step 620 is similar to the step 612 in which the terminal device accesses the target master cell group corresponding to MN2. For details, refer to the description of the step 612.

[0337] 621. The MN3 sends SN reconfiguration complete information to the SN. Correspondingly, the SN receives the reconfiguration complete information from the MN3.

[0338] Optionally, the SN reconfiguration complete information can include the identification of the target master cell group and / or the candidate configuration identification of the target master cell group. For example, the identification of the target master cell group belongs to the identification of the candidate master cell group of MN3, and the candidate configuration identification of the target master cell group belongs to the candidate configuration identification of the candidate master cell group of MN3.

[0339] It should be understood that the identification of the target master cell group and / or the candidate configuration identification of the target master cell group can be transmitted through separate signaling, and not retransmitted in the SN reconfiguration complete information. The step 613 is an optional step.

[0340] 622. The terminal device accesses the SN.

[0341] It should be understood that after the terminal device accesses the target master cell group of MN3, the terminal device communicates with the SN according to the secondary station key corresponding to the target master cell group configuration of MN3 determined by the terminal device. Thus, in the case of switching the target master station of the terminal device to MN3, the terminal device and the SN can still communicate and maintain high-speed data transmission.

[0342] It should also be understood that the steps 615 to 622 described above are for the case where the candidate MN includes only MN3. In the case where the candidate MN includes multiple MNs, such as MN3 and MN4, etc., the SN obtains multiple secondary station keys and selects the secondary station key corresponding to the target master cell group configuration from the multiple secondary station keys in the case where the terminal device accesses the SN. For details, refer to the detailed description of the steps 608 to 614.

[0343] Based on the method shown in the above Fig. 6, after the candidate MN (such as MN2 and MN3) obtains the master station key corresponding to the candidate master cell group of the respective master station in advance, the secondary station key corresponding to the candidate master cell group is derived in advance and indicated to the SN, so that the SN can obtain the secondary station key corresponding to the candidate master cell group of the candidate MN in advance, and the data transmission on the SN side can be restored as soon as possible when the terminal device performs MN switching, thereby ensuring the user experience.

[0344] The technical solutions provided by the present application will be described in detail below with reference to FIG. 7. The embodiments of the present application can be applied to multiple different scenarios, including the scenario shown in FIG. 1, but are not limited to this scenario. For example, the embodiments of the present application can also be applied to 5G or future communication networks.

[0345] It should be understood that the embodiments shown below do not particularly limit the specific structure of the subject performing the method provided by the embodiments of the present application, as long as the subject can communicate according to the method provided by the embodiments of the present application by running a program in which the code of the method provided by the embodiments of the present application is recorded. For example, the subject performing the method provided by the embodiments of the present 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 invoke and execute the program.

[0346] In the following, without loss of generality, the communication method provided by the embodiments of the present application will be described in detail by taking the interaction between a first communication device, a second communication device, a third communication device and a terminal device as an example. The first communication device can be a target master station (or a centralized unit (CU) or a distributed unit (DU) in the target master station) to which the terminal device switches; or the second communication device can be a secondary station that provides services for the terminal device; or the third communication device can be a source master station (or a centralized unit (CU) or a distributed unit (DU) in the source master station) that provides services for the terminal device.

[0347] FIG. 7 is a schematic flowchart of a communication method provided by an embodiment of the present application. As shown in FIG. 7, the method can include the following steps:

[0348] 701. At least one candidate communication device sends at least one addition request information to the second communication device. Correspondingly, the second communication device receives the at least one addition request information from the at least one candidate communication device.

[0349] It should be understood that the second communication device is a secondary station that provides services for the terminal device.

[0350] It should also be understood that the configuration of the candidate cell group of the at least one candidate communication device corresponds to the at least one addition request information. Assuming that the at least one candidate communication device includes two communication devices (for example, the first communication device and the 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 addition request information, wherein the four addition request information respectively correspond one-to-one to the configurations of cell group #1, cell group #2, cell group #3 and cell group #4.

[0351] wherein the at least one candidate cell group of the first communication device comprises at least one candidate primary cell group (e.g. cell group #1), and the at least one candidate cell group of the second communication device comprises at least one candidate primary cell group (e.g. cell group #4).

[0352] It is assumed that the at least one candidate communication device comprises a first communication device, which sends a first addition request information to the second communication device. Wherein the first communication device is a target primary station of terminal device switching.

[0353] In a possible implementation, after the at least one candidate communication device receives the handover request information from the third communication device, the at least one candidate communication device sends at least one addition request information to the second communication device. For example, step 501 in FIG. 5 and step 601 in FIG. 6.

[0354] In a possible implementation, taking the first communication device in the at least one candidate communication device as an example, the addition request information of the first communication device can comprise 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 terminal device switching, or information indicating that the first communication device is a candidate communication device of terminal device cross-base station or cross-centralized unit switching.

[0355] Similarly, the addition request information of the fourth communication device can comprise one or more of the following information: information indicating that the fourth communication device is a candidate communication device of terminal device switching, information indicating that the fourth communication device is a candidate communication device of subsequent terminal device switching, or information indicating that the fourth communication device is a candidate communication device of terminal device cross-base station or cross-centralized unit switching.

[0356] It should be understood that the addition request information sent by the at least one candidate communication device can further comprise the secondary station key indicated by the at least one candidate communication device. It is assumed that the addition request information sent by the at least one candidate communication device comprises at least one secondary station key corresponding to the configuration of the at least one candidate primary cell group of the at least one candidate communication device, and the second communication device receives the addition request information, and ignores the secondary station key included in the addition request information.

[0357] It should also be understood that the detailed example of step 701 can refer to step 502 in FIG. 5 and step 602 in FIG. 6.

[0358] 702, the second communication device sends at least one addition request confirmation information to the at least one candidate communication device.

[0359] It should be understood that the adding request confirmation information is used to answer the adding request information in step 701.

[0360] Optionally, the at least one adding request information comprises at least one second identifier and / or at least one random access resource. The random access resource is a random access resource of a target secondary cell group corresponding to the target master cell group. The at least one second identifier and / or at least one random access resource correspond to the configuration of the at least one candidate master cell group of the at least one candidate communication device.

[0361] For example, the second identifier in the at least one second identifier can be a C-RNTI. The at least one second identifier comprises a first identifier, which corresponds to the configuration of the candidate master cell group of the first communication device.

[0362] 703, the at least one candidate communication device sends at least one handover request confirmation information to the third communication device. Accordingly, the third communication device receives the at least one handover request confirmation information from the at least one candidate communication device.

[0363] It should be understood that the at least one handover request confirmation information corresponds to the configuration of the at least one candidate master cell group of the at least one candidate communication device. The at least one handover request information comprises the configuration information of the at least one candidate master cell group of the at least one candidate communication device and at least one count value corresponding to the configuration of each candidate master cell group.

[0364] Optionally, the third communication device is a source master station providing services for the terminal device.

[0365] It should also be understood that the detailed examples of step 703 can refer to step 504 in FIG. 5 and step 604 in FIG. 6 described above.

[0366] Optionally, the at least one handover request information comprises at least one second identifier and / or at least one random access resource corresponding to the configuration of the at least one candidate master cell group of the at least one candidate communication device.

[0367] 704, the third communication device sends RRC reconfiguration information to the terminal device. Accordingly, the terminal device receives the RRC reconfiguration information of the third communication device.

[0368] Optionally, the RRC reconfiguration information comprises the configuration information of the candidate master cell group of each candidate communication device in the at least one candidate communication device and at least one count value corresponding to the candidate master cell group of each candidate communication device.

[0369] Optionally, the RRC reconfiguration information further comprises at least one second identifier and / or at least one random access resource corresponding to the configuration of the at least one candidate master cell group of the at least one candidate communication device in step 702.

[0370] It should be understood that the detailed example of this step 704 can refer to the step 505 in the above-mentioned Fig. 5, the step 605 in the Fig. 6.

[0371] 705, the third communication device sends fourth information to the terminal device. Correspondingly, the terminal device receives the fourth information of the third communication device.

[0372] The fourth information includes at least one NCC corresponding to the configuration of the candidate master cell group of the at least one candidate communication device. Taking the first NCC corresponding to the configuration of the candidate master cell group of the first communication device as an example, it is assumed that the first communication device corresponds to one candidate master cell group, and the candidate master cell group of the first communication device corresponds to the first NCC in the fourth information, which is used to determine the master key corresponding to the configuration of the candidate master cell group of the first communication device.

[0373] Optionally, the fourth information further includes at least one counting value corresponding to the configuration of at least one candidate master cell group of each candidate communication device in the at least one candidate communication device.

[0374] It should be understood that the fourth information in this step 705 is equivalent to the information #1 in the step 507 in the Fig. 5, the information #1 in the step 607 in the Fig. 6. The detailed description can refer to the description in the above-mentioned Fig. 5 and Fig. 6.

[0375] 706, the third communication device sends a handover command to the terminal device. Correspondingly, the terminal device receives the handover command of the third communication device.

[0376] The handover command is used to indicate the identity of the target master cell group of the terminal device for handover.

[0377] It should be understood that the detailed example of this step 706 can refer to the step 508 in the above-mentioned Fig. 5, the step 610 in the Fig. 6. The detailed description can refer to the description in the above-mentioned Fig. 5 and Fig. 6.

[0378] Next, the subsequent steps in Fig. 7 will be introduced in two cases respectively:

[0379] Case one:

[0380] 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.

[0381] It should be understood that, assuming that the first communication device is a target master station of terminal device switching determined by the third communication device from the at least one candidate communication device, the target master cell group of the terminal device switching 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 a candidate configuration identifier corresponding to the target master cell group of the terminal device switching, the target master cell group belonging to the candidate master cell group of the first communication device.

[0382] Optionally, the first information includes a master station key corresponding to the configuration of the candidate master cell group of the first communication device.

[0383] It should also be understood that, assuming that the master station key corresponding to the configuration of the candidate master cell group of the first communication device is not included in the first information, the third communication device can send the master station key to the first communication device through other signaling. The third communication device sends the master station key to the first communication device simultaneously or sequentially with the sending of the first information, which is not limited by the present application.

[0384] It should be understood that the execution sequence of step 707 and step 706 is not limited. The specific example of step 707 can be found in step 509 in FIG. 5.

[0385] 708, the first communication device sends a first secondary station key to the second communication device. Correspondingly, the second communication device receives the first secondary station key from the first communication device.

[0386] In one possible implementation, assuming that the configuration of the target master cell group of the terminal device switching corresponds to one count value (for example, a first count value). After the first communication device receives the master station key, the first communication device determines the first secondary station key according to the first count value, and sends the first secondary station key to the second communication device.

[0387] In another possible implementation, assuming that the configuration of the target master cell group of the terminal device switching corresponds to multiple count values, wherein the multiple count values include the first count value, and the first count value is the first unused count value in the multiple count values. After the first communication device receives the master station key, the first communication device determines the first secondary station key according to the first count value, and sends the first secondary station key to the second communication device.

[0388] Optionally, the first secondary station key in step 708 can be carried in the SN reconfiguration complete information for transmission.

[0389] It should be understood that the specific example of step 708 can be found in step 510 in FIG. 5.

[0390] 709, the terminal device accesses the target master cell group corresponding to the first communication device.

[0391] It should be understood that after the terminal device receives the handover command from the third communication device in step 706, the terminal device can calculate the master key corresponding to the configuration of the target master cell group of the first communication device based on the NCC corresponding to the target master cell group of the first communication device stored locally in the fourth information according to the handover command. The terminal device accesses the target master cell group of the first communication device according to the master key and performs secure communication with the first communication device.

[0392] It should be understood that a specific example of this step 709 can be seen in step 511 of the above-mentioned FIG. 5.

[0393] 710, the terminal device accesses the second communication device.

[0394] It should be understood that after the terminal device accesses the target master cell group of the first communication device, the terminal device can communicate with the second communication device according to the secondary key determined in step 709, so as to realize that the terminal device and the second communication device can still communicate and maintain the transmission of high-speed data in the case of switching the target master station of the terminal device to the first communication device.

[0395] Case two:

[0396] 711, the third communication device sends the master key corresponding to the configuration of the candidate master cell group of the first communication device to the first communication device, and sends the master key corresponding to the configuration of the candidate master cell group of the fourth communication device to the fourth communication device.

[0397] Correspondingly, the first communication device receives the master key corresponding to the configuration of the candidate master cell group of the first communication device sent by the third communication device. The fourth communication device receives the master key corresponding to the configuration of the candidate master cell group of the fourth communication device sent by the third communication device.

[0398] It should be understood that the master key corresponding to the configuration of the candidate master cell group of the first communication device can be carried in the first information, which is similar to the above-mentioned step 707.

[0399] It should also be understood that the execution order of steps 711 and 706 is not limited. A specific example of this step 711 can be seen in step 608 of the above-mentioned FIG. 6.

[0400] 712, the first communication device sends the secondary station key #1 to the second communication device, and the fourth communication device sends the secondary station key #2 to the second communication device. Correspondingly, the second communication device receives the secondary station key #1 from the first communication device, and the second communication device receives the secondary station key #2 from the first communication device.

[0401] It should be understood that the secondary station key #1 received by the second communication device is associated with the identification of the candidate master cell group of the first communication device and / or the candidate configuration identification of the candidate master cell group, and the secondary station key #2 is associated with the identification of the candidate master cell group of the fourth communication device and / or the candidate configuration identification of the candidate master cell group.

[0402] It should also be understood that a specific example of this step 712 can refer to the step 609 in the above-mentioned FIG. 6, where the first communication device can be the MN2 in the above-mentioned FIG. 6, the second communication device can be the SN in the above-mentioned FIG. 6, and the fourth communication device can be the MN3 in the above-mentioned FIG. 6.

[0403] 713, the terminal device accesses the candidate master cell group corresponding to the first communication device.

[0404] It should be understood that assuming that the target master cell group of the terminal device switching belongs to the candidate master cell group of the first communication device. After the terminal device receives the handover command from the third communication device in step 706, the terminal device calculates and deduces the master station key corresponding to the configuration of the target master cell group of the first communication device based on the NCC corresponding to the target master cell group of the first communication device stored locally in the fourth information. The terminal device accesses the target master cell group of the first communication device using the master station key used for communication between the terminal device and the first communication device calculated and deduced, and performs secure communication with the first communication device.

[0405] It should be understood that a specific example of this step 713 can refer to the step 612 in the above-mentioned FIG. 6.

[0406] 714, the first communication device sends the secondary station reconfiguration completion information to the second communication device. Correspondingly, the second communication device receives the secondary station reconfiguration completion information from the first communication device.

[0407] Optionally, the secondary station reconfiguration completion information includes the identification of the target cell group and / or the candidate configuration identification of the target cell group. For example, the identification of the target master cell group belongs to the identification of the candidate master cell group of the first communication device, and the candidate configuration identification of the target master cell group belongs to the candidate configuration identification of the candidate master cell group of the first communication device.

[0408] It should be understood that the identification of the target master cell group and / or the candidate configuration identification of the target master cell group can be transmitted by separate signaling, and not retransmitted by the secondary station reconfiguration completion information. This step 714 is an optional step.

[0409] 715, the terminal device accesses the second communication device.

[0410] It should be understood that after the terminal device accesses the target master cell group of the first communication device, the terminal device communicates with the second communication device according to the determined secondary station key corresponding to the configuration of the target master cell group of the first communication device, so that in the case that the target master 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 the transmission of high-speed data.

[0411] It should also be understood that the method of selecting the secondary station key corresponding to the configuration of the target master cell group from the plurality of secondary station keys by the second communication device can refer to the detailed description of the methods 1 to 4 in step 614.

[0412] Based on the method shown in FIG. 7, in the case that the master station serving the terminal device is switched and the secondary station remains in the subsequent switching scenario, the terminal device can timely and accurately obtain the updated secondary station key, and the normal communication between the terminal device and the secondary station is ensured.

[0413] It should be understood that the methods provided by the embodiments of the present application can be applied in the CU-DU separated architecture. Taking FIG. 5 as an example, MN1 can be split into CU1 and DU1, MN2 can be split into CU2 and DU2, MN3 can be split into CU3 and DU3, and SN can be split into CU and DU. The Xn interface for communication between the MNs and the MN / SN corresponds to the interface between the CUs and the CUs, i.e., the information exchange between the MN1, MN2, MN3 and SN in the above corresponds to the communication between the CUs and the CUs. For example, steps 501, 502, 503, 504, 509, 510, 511, 512, etc. In step 506, the terminal device reports the measurement report to the DU1 of MN1, and the DU1 determines the target master station for the terminal device based on the measurement report. In step 507, the information #1 can be sent by the CU1 to the DU1, and then sent by the DU1 to the terminal device. In step 508, the switching command can be sent by the DU1 of MN1 to the terminal device. Similarly, in step 513, the information #3 can be sent by the CU2 of MN2 to the DU2, and then sent by the DU2 to the terminal device. In step 514, the switching command can be sent by the DU2 of MN2 to the terminal device.

[0414] It should be understood that the size of the serial number of the above processes does not mean the order of execution, and the execution order of the processes should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0415] It should also be understood that, in various embodiments of the present application, the terms and / or descriptions between different embodiments are consistent and can be referred to each other if there is no special description and logical conflict, and the technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0416] It should also be understood that, in some of the above embodiments, the devices in the existing network architecture are mainly exemplarily described, and it should be understood that the specific forms of the devices are not limited in the embodiments of the present application. For example, devices that can realize the same functions in the future are also applicable to the embodiments of the present application.

[0417] It can be understood that, in each of the above method embodiments, the methods and operations implemented by the 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 for the devices.

[0418] It can also be understood that some optional features in various embodiments of the present application can not depend on other features in some scenarios, or can be combined with other features in some scenarios, and are not limited.

[0419] The above, in combination with FIGS. 3 to 7, details the communication method provided by the embodiments of the present application. The above communication method is mainly introduced from the perspective of the first communication device (such as MN2), the second communication device (such as SN), the third communication device (such as MN1) and the terminal device. It can be understood that the first communication device, the second communication device, the third communication device and the terminal device contain corresponding hardware structures and / or software modules for executing various functions in order to realize the above functions.

[0420] Those skilled in the art should realize that, in combination with the units and algorithm steps of the examples described in the embodiments disclosed herein, the present application can be realized in the form of hardware or a combination of hardware and computer software. Whether a certain function is realized in the form of hardware or computer software driving hardware depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods to realize the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0421] The following, in combination with FIGS. 8 to 10, details the communication device provided by the embodiments of the present application. It should be understood that the description of the device embodiments corresponds to the description of the method embodiments, therefore, the contents not described in detail can be referred to the above method embodiments, and some contents will not be described again for brevity.

[0422] The embodiments of the present application can divide the function modules of the sending terminal device or the receiving terminal device according to the above method examples. For example, each function module can be divided according to each function, or two or more functions can be integrated in one processing module. The integrated module can be realized in the form of hardware or in the form of a software function module. It should be noted that the division of the modules in the embodiments of the present application is illustrative, and is only a logical function division. In actual implementation, another division manner can be used. The following will be described by taking the division of each function module according to each function as an example.

[0423] FIG. 8 is a schematic block diagram of the communication apparatus 10 provided by the embodiments of the present application. The apparatus 10 includes a transceiver module 11 and a processing module 12. The transceiver module 11 can realize corresponding communication functions, and the processing module 12 is used for data processing, that is, the transceiver module 11 is used for performing operations related to receiving and sending, and the processing module 12 is used for performing operations other than receiving and sending. The transceiver module 11 can also be referred to as a communication interface or a communication unit.

[0424] Optionally, the apparatus 10 can further include a storage module 13, which can be used for storing instructions and / or data. The processing module 12 can read the instructions and / or data in the storage module, so that the apparatus realizes the actions of the device in the foregoing various method embodiments.

[0425] In one design, the apparatus 10 can correspond to the first communication apparatus in the above method embodiments, or be a constituent component (such as a chip) of the first communication apparatus.

[0426] The apparatus 10 can realize the steps or processes performed by the first communication apparatus corresponding to the above method embodiments. The transceiver module 11 can be used to perform the operations related to receiving and sending of the first communication apparatus in the above method embodiments, and the processing module 12 can be used to perform the processing-related operations of the first communication apparatus in the above method embodiments.

[0427] In one possible implementation, the transceiver module 11 is configured to send addition request information to a second communication apparatus. The transceiver module 11 is further configured to receive addition request confirmation information of the second communication apparatus. After the transceiver module 11 receives the addition request confirmation information, the transceiver module 11 is further configured to receive a master key corresponding to a configuration of a candidate cell group of the first communication apparatus. The processing module 12 is configured to send, to the second communication apparatus, a first secondary key through the transceiver module 11 according to the master key, where the first communication apparatus is a target master of a terminal device switching, the second communication apparatus is a secondary station providing a service for the terminal device, and the candidate cell group includes a candidate master cell group.

[0428] When the apparatus 10 is configured to perform the method in FIG. 5, the first communication device is MN2, the transceiver module 11 can be configured to perform the steps of receiving and / or transmitting information in the method, such as steps 501, 502, 503, 504, 509, 510, 511, and the processing module 12 can be configured to perform the steps of processing in the method.

[0429] When the apparatus 10 is configured to perform the method in FIG. 6, the first communication device is MN2, the transceiver module 11 can be configured to perform the steps of receiving and / or transmitting 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 configured to perform the steps of processing in the method.

[0430] When the apparatus 10 is configured to perform the method in FIG. 7, the transceiver module 11 can be configured to perform the steps of receiving and / or transmitting 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 configured to perform the steps of processing in the method.

[0431] It should be understood that the specific processes by which the units perform the corresponding steps are described in detail in the method embodiments above, and thus will not be repeated here for brevity.

[0432] In another design, the apparatus 10 can correspond to, or be a component (e.g., a chip) of, the second communication device in the method embodiments above.

[0433] The apparatus 10 can implement the steps or procedures performed by the second communication device in the method embodiments above, where the transceiver module 11 can be configured to perform the operations related to receiving and / or transmitting of the second communication device in the method embodiments above, and the processing module 12 can be configured to perform the operations related to processing of the second communication device in the method embodiments above.

[0434] In a possible implementation, the transceiver module 11 is configured to receive at least one addition request information from at least one candidate communication device; the transceiver module 11 is further configured to send at least one addition request confirmation information to the at least one candidate communication device; after the transceiver module 11 sends the at least one addition request confirmation information, the transceiver module 11 is further configured to receive at least one secondary station key, the at least one secondary station key corresponding to a configuration of at least one candidate cell group of the 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 comprises 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 the candidate primary cell group of the first communication device, and the second communication device being a secondary station serving the terminal device.

[0435] When the apparatus 10 is configured to perform the method in FIG. 5, the second communication device is an SN, the transceiver module 11 can be configured to perform the steps of receiving and sending information in the method, such as steps 502, 503, 510 and 516, and the processing module 12 can be configured to perform the processing steps in the method.

[0436] When the apparatus 10 is configured to perform the method in FIG. 6, the second communication device is an SN, the transceiver module 11 can be configured to perform the steps of receiving and sending information in the method, such as steps 602, 603, 609, 613, 617, 621 and 622, and the processing module 12 can be configured to perform the processing steps in the method.

[0437] When the apparatus 10 is configured to perform the method in FIG. 7, the transceiver module 11 can be configured to perform the steps of receiving and sending information in the method, such as steps 701, 702, 708, 712, 714 and 715, and the processing module 12 can be configured to perform the processing steps in the method.

[0438] In one design, the apparatus 10 can correspond to a terminal device in the above method embodiments, or be a component (such as a chip) of the terminal device.

[0439] The apparatus 10 can implement the steps or procedures performed by a terminal device in the above method embodiments, where the transceiver module 11 can be configured to perform the receiving and sending related operations of the terminal device in the above method embodiments, and the processing module 12 can be configured to perform the processing related operations of the terminal device in the above method embodiments.

[0440] In a possible implementation, the transceiver module 11 is configured to receive a radio resource control (RRC) reconfiguration information from a third communication device;

[0441] At the transceiver module 11, 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 comprising at least one next hop chaining count (NCC), the at least one NCC corresponding to a configuration of a candidate cell group of at least one candidate communication device, a first NCC of the at least one NCC being used to determine a master key corresponding to a configuration of a candidate cell group of a first communication device, the at least one candidate communication device comprising the first communication device, and the candidate cell group comprising a candidate master cell group. The first communication device is a target master for a terminal device to switch to, and the third communication device is a source master serving the terminal device. The fourth information further comprises at least one counter value corresponding to the configuration of the candidate cell group of each of the at least one candidate communication device, and the RRC reconfiguration information comprises configuration information of the candidate cell group of each of the at least one candidate communication device and at least one counter value corresponding to the configuration information of the candidate cell group.

[0442] It should be understood that the specific processes by which the units perform the respective steps described above have been described in detail in the method embodiments described above, and for the sake of brevity, will not be repeated here.

[0443] It should also be understood that the apparatus 10 herein is embodied in the form of functional modules. The term "module" herein can refer to an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that execute one or more software or firmware programs, a combinational logic circuit, and / or other suitable components that provide the described functionality. In one optional example, those skilled in the art can understand that the apparatus 10 can be embodied as the mobility management network element in the above embodiments, and can be configured to perform the respective processes and / or steps corresponding to the mobility management network element in the above method embodiments. Alternatively, the apparatus 10 can be embodied as the terminal device in the above embodiments, and can be configured to perform the respective processes and / or steps corresponding to the terminal device in the above method embodiments. To avoid repetition, these will not be repeated here.

[0444] The apparatus 10 of each of the above solutions has a function of implementing the corresponding steps performed by the device (e.g., the first communication apparatus, the second communication apparatus, the third communication apparatus, the terminal device) in the above method. The 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 functions; for example, the transceiver module can be replaced by a transceiver (e.g., the sending 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 the processing module can be replaced by a processor, which respectively perform the transceiving operations and related processing operations in each method embodiment.

[0445] In addition, the transceiver module 11 described above can also be a transceiver circuit (e.g., which can include a receiving circuit and a sending circuit), and the processing module can be a processing circuit.

[0446] FIG. 9 is a schematic diagram of another communication apparatus 20 provided by an embodiment of the present application. The apparatus 20 includes a processor 21 configured to execute computer programs or instructions stored in a memory 22, or read data / signaling stored in the memory 22, to perform the methods in the above method embodiments. Optionally, the processor 21 is one or more.

[0447] Optionally, as shown in FIG. 9, the apparatus 20 further includes the memory 22 configured to store computer programs or instructions and / or data. The memory 22 can be integrated with the processor 21, or can be separately arranged. Optionally, the memory 22 is one or more.

[0448] Optionally, as shown in FIG. 9, the apparatus 20 further includes a transceiver 23 configured to receive and / or send signals. For example, the processor 21 is configured to control the transceiver 23 to receive and / or send signals.

[0449] As one solution, the apparatus 20 is configured to implement the operations performed by the first communication apparatus or the second communication apparatus in the above method embodiments.

[0450] It should be appreciated that a processor as mentioned in this application can be any known or future developed processor, and more particularly, any custom made or commercially available processor series (or any other processor orders) from any manufacturer.

[0451] It should also be appreciated that a memory as mentioned in this application can be any known or future developed memory, and more particularly, a memory unit of any type including, but not limited to, a volatile memory, a non-volatile memory, or a combination thereof. For example, the non-volatile memory can be a read-only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically EPROM (EEPROM), a flash memory, or the like. The volatile memory can be a random access memory (RAM), which can be used as external cache memory. By way of example and not limitation, RAM is available from many commercial vendors. For example, the RAM can include a static RAM (SRAM), a dynamic RAM (DRAM), a synchronous DRAM (SDRAM), a double data rate SDRAM (DDR SDRAM), an enhanced SDRAM (ESDRAM), a synchlink DRAM (SLDRAM), and a direct rambus RAM (DR RAM), etc.

[0452] It should be noted that when the processor is a general processor, a DSP, an ASIC, a FPGA, or other programmable logic device, a discrete gate or transistor logic, a discrete hardware component, the memory (storage module) can be integrated in the processor.

[0453] It should also be noted that the memory described herein is intended to include, but not limited to, the memory of these and any other suitable type of memory.

[0454] FIG. 10 is a schematic diagram of a chip system 30 according to an embodiment of the present application. The chip system 30 (or also referred to as a processing system) includes a logic circuit 31 and an input / output interface 32.

[0455] The logic circuit 31 can be a processing circuit in the chip system 30. The logic circuit 31 can be coupled to a storage unit, and invoke instructions in the storage unit, so that the chip system 30 can implement the methods and functions of the embodiments of the present application. The input / output interface 32 can be an input / output circuit in the chip system 30, and output information processed by the chip system 30, or input data or signaling information to be processed by the chip system 30.

[0456] As an option, the chip system 30 is configured to implement operations performed by the first communication device or the second communication device in the above method embodiments.

[0457] For example, the logic circuit 31 is configured to implement processing-related operations performed by the first communication device or the second communication device in the above method embodiments; and the input / output interface 32 is configured to implement sending and / or receiving-related operations performed by the terminal device in the above method embodiments.

[0458] The embodiments of the present application also provide a computer readable storage medium, which stores computer instructions for implementing the method performed by the device in the above method embodiments.

[0459] For example, the computer program is executed by a computer, so that the computer can implement the method performed by the first communication device, the second communication device, the third communication device, or the terminal device in the above method embodiments.

[0460] The embodiments of the present application also provide a computer program product, which includes instructions, and the instructions are executed by a computer to implement the method performed by the first communication device, the second communication device, the third communication device, or the terminal device in the above method embodiments.

[0461] The embodiments of the present application also provide a communication system, which includes the first communication device, the second communication device, and the third communication device.

[0462] The explanations and beneficial effects of the related contents in any of the above devices can refer to the corresponding method embodiments provided above, and will not be repeated here.

[0463] Those skilled in the art can clearly understand that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed 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 the present application.

[0464] Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working processes of the above-described system, device and unit can refer to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

[0465] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other ways. For example, the above-described device embodiments are merely schematic, for example, the division of the units is only a logical function division, and actual implementation can have another division manner, for example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the units shown or discussed can be indirect coupling or communication connection through some interfaces, devices or units, which can be electrical, mechanical or other forms.

[0466] The units described as separate components can or can not be physically separated, and the components shown as units can or can not be physical units, that is, they can be located in one place, or can be distributed on multiple network units. Part or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0467] In addition, each functional unit in each embodiment of the present application can be integrated into a processing unit, or each unit can exist physically independently, or two or more units can be integrated into one unit.

[0468] If the functions are implemented in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the parts that contribute to the prior art or parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (Read-Only Memory, ROM), a random access memory (Random Access Memory, RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0469] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection 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 has stored thereon 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 in which the chip system is installed 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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