Communication method and device

Abstract

The embodiment of the invention provides a communication method and device, and the method comprises the steps that terminal equipment receives a first switching message from first access network equipment, the first switching message is used for indicating the terminal equipment to be switched from a first cell where the terminal equipment is located currently to a second cell, and the second cell is a cell administered by second access network equipment; and the terminal device performs first data transmission with the second access network device by using a secret key of the first cell based on the first switching message. By means of the method, it can be ensured that the duration of communication interruption is short when the terminal equipment executes cell switching.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a communication method and device. Background Art

[0002] In a mobile communication system, the communication link between the terminal device and the access network device changes due to the movement of the terminal. The access network device will instruct the terminal device to switch cells according to the movement of the terminal device. In the process of switching from the source cell to the target cell, there may be a period of interruption, affecting the user experience.

[0003] The current solution to this problem is that the terminal device maintains communication with the source base station and the target base station through two communication links, and the communication uses a dual-activation protocol stack. However, such a solution is complex to implement, has high hardware requirements, and is costly to implement. Therefore, how to achieve low-interruption cell switching (or base station switching) for terminal devices with low complexity and low hardware cost is one of the problems that need to be solved urgently. Summary of the invention

[0004] The present application proposes a communication method and apparatus, which can ensure that the duration of communication interruption during cell switching of a terminal device is short.

[0005] In the first aspect, the present application implements a communication method, which can be executed by a terminal device or by a chip corresponding to the terminal device, without limitation. The method can specifically include: receiving a first switching message from a first access network device, the first switching message being used to instruct the terminal device to switch from a first cell currently located to a second cell, the second cell being a cell under the jurisdiction of a second access network device; based on the first switching message, using a secret key of the first cell to perform first data transmission with the second access network device.

[0006] In the embodiment of the present application, the first cell refers to the cell that the terminal device is currently connected to, and the terminal device communicates with the first access network device (e.g., a base station) through the first cell. The second cell is a cell that the terminal device is not currently connected to but is about to access, and the terminal device can communicate with the second access network device by accessing the second cell. In the above, the secret key of the first cell is deduced based on the configuration information of the secret key of the first cell.

[0007] In the present application scheme, when a terminal device receives a first switching message from a first access network device to instruct the terminal device to switch from the first cell in which it is currently located to the second cell, the terminal device can still use the secret key of the first cell to transmit data with the second access network device, thereby ensuring that the duration of communication interruption when the terminal device performs cell switching is short.

[0008] In a possible implementation manner, the first switching message includes cell configuration indication information, where the cell configuration indication information is used to indicate that the second cell uses the same configuration information as that of the first cell.

[0009] Through this implementation, the configuration information used by the second cell to be switched is indicated to the terminal device as being the same as the configuration information of the first cell where the terminal device is currently located. The terminal device can then quickly and accurately establish a communication connection with the second cell with reference to the configuration information of the first cell.

[0010] In one possible implementation, the terminal device uses the secret key of the first cell to perform first data transmission with the second access network device, including: when a communication connection is established with the second cell and the secret key of the second cell is not deduced, using the secret key of the first cell to perform first data transmission with the second access network device.

[0011] Through this implementation, it is possible to ensure that the terminal device communicates effectively with the second cell and to effectively reduce the duration of communication interruption that occurs when the terminal device performs cell switching.

[0012] In one possible implementation, the terminal device uses the secret key of the first cell to perform first data transmission with the second access network device, including: using the secret key of the first cell to encrypt and integrity protect the uplink data to obtain uplink first data; sending the uplink first data to the second access network device; and / or receiving downlink first data from the second access network device, and using the secret key of the first cell to decrypt and integrity check the downlink first data.

[0013] Through this implementation, the terminal device can use the key of the first cell to perform effective uplink and / or downlink data transmission with the second access network device.

[0014] In a possible implementation, after the terminal device establishes a communication connection with the second cell, the method further includes: receiving configuration information of a secret key of the second cell from the second access network device.

[0015] Through this implementation, the terminal device can effectively deduce the secret key of the second cell by using the configuration information of the secret key of the second cell.

[0016] In a possible implementation, the method also includes: the terminal device identifies the first data through a first target identifier, and the first target identifier may be but is not limited to: an identifier of a first bearer, or an identifier of a first logical channel, or a first identifier carried in the first data; wherein the first identifier may be used to indicate which data belongs to the first data; the first bearer or the first logical channel is used to transmit the first data.

[0017] Through this implementation, the terminal device can effectively and accurately identify that the data from the second access network device is the first data, and then can accurately use the key of the first cell to process the first data.

[0018] In one possible implementation, after the terminal device derives the secret key of the second cell, the method further includes: the terminal device uses the secret key of the second cell to encrypt and integrity protect the uplink data to obtain uplink second data; sends the uplink second data to the second access network device; and / or receives downlink second data from the second access network device, and uses the secret key of the second cell to decrypt and integrity check the downlink second data.

[0019] Through this implementation, after deducing the secret key of the second cell, the terminal device can effectively use the secret key of the second cell to perform data transmission with the second access network device.

[0020] In a possible implementation, the method also includes: the terminal device can identify the second data through a second target identifier, and the second target identifier can be but is not limited to: an identifier of a second bearer, or a second logical channel identifier, or a second identifier carried in the second data, wherein the second identifier can be used to indicate which data belongs to the second data; the second bearer or the second logical channel is used to transmit the second data.

[0021] Through this implementation, the terminal device can effectively and accurately identify that the data from the second access network device is the second data, and then can accurately use the secret key of the second cell to process the second data.

[0022] In a possible implementation, the method also includes: the terminal device receives first indication information from the second access network device, and the first indication information is used to instruct the terminal device to perform one or more of the following: stop using the key of the first cell to process data, delete the key of the first cell, stop processing associated with the key of the first cell, release the first bearer or first logical channel of the first data, and stop carrying the second identifier in the second data.

[0023] Through this implementation, the terminal device can stop using the secret key of the first cell and stop communicating with the first cell.

[0024] In the second aspect, the present application implements a communication method, which can be executed by a first access network device or by a chip corresponding to the first access network device, without limitation. The method can specifically include: sending a first switching message to a terminal device, the first switching message is used to instruct the terminal device to switch from the current first cell to the second cell, the second cell being a cell under the jurisdiction of the second access network device; using the secret key of the first cell to perform first data transmission with the second access network device.

[0025] In the embodiment of the present application, the first cell refers to the cell that the terminal device is currently connected to, and the terminal device communicates with the first access network device (e.g., a base station) through the first cell. The second cell is a cell that the terminal device is not currently connected to but is about to access, and the terminal device can communicate with the second access network device by accessing the second cell. In the above, the secret key of the first cell is deduced based on the configuration information of the secret key of the first cell.

[0026] In the present application scheme, when the first access network device instructs the terminal device to switch from the current first cell to the second cell, the first access network device can use the secret key of the first cell to perform the first data transmission with the second access network device. Correspondingly, the terminal device side can also use the secret key of the first cell to perform the first data transmission with the second access network device, which is equivalent to the first access network device and the terminal device can use the second access network device to perform the first data transmission, thereby ensuring that the terminal device has a short communication interruption duration when performing cell switching.

[0027] In a possible implementation, before the first access network device sends a first switching message to the terminal device, the method also includes: sending a first switching request message to the second access network device, the first switching request message including the address information of the user plane tunnel of the first access network device; receiving a first switching response message from the second access network device, the first switching response message including the address information of the user plane tunnel of the second access network device.

[0028] Through this implementation, accurate and effective data transmission between the first access network device and the second access network device can be ensured.

[0029] In a possible implementation, the first switching request information also includes third indication information, and the third indication information is used to request the second cell to use the configuration information of the first cell; the first switching response information is used to indicate that the second cell confirms the use of the configuration information of the first cell; wherein the configuration information of the first cell includes the uplink physical layer channel configuration information of the first cell and the downlink physical layer channel configuration information of the first cell.

[0030] Through this implementation, the second cell can effectively use the same configuration information as the first cell, so that subsequent terminal devices can quickly and accurately access the second cell.

[0031] In a possible implementation, before the first access network device uses the secret key of the first cell to perform first data transmission with the second access network device, the method also includes: receiving a first response message from the terminal device, the first response message being used to notify the terminal device to confirm switching from the first cell to the second cell; using the secret key of the first cell to perform first data transmission with the second access network device, including: using the secret key of the first cell to encrypt and integrity protect the downlink data to obtain downlink first data; sending the downlink first data to the second access network device according to the address information of the user plane tunnel of the second access network device; and / or receiving uplink first data from the second access network device, and using the secret key of the first cell to decrypt and integrity check the uplink first data to obtain uplink data.

[0032] Through this implementation, after the terminal device confirms switching from the first cell to the second cell, the first access network device uses the key of the first cell to perform effective uplink and / or downlink first data transmission with the second access network device.

[0033] In a possible implementation, the method also includes: the first access network device receives second indication information from the second access network device, the second indication information is used to instruct the first cell or the first access network device to stop generating or sending the first data and release the first bearer or first logical channel of the first data; and sends first status information to the second access network device, the first status information is used to indicate identification information of the first data that has been successfully sent and / or unsuccessfully sent.

[0034] Through this implementation, the first access network device no longer uses the key of the first cell to process data and stops the communication of the first cell. At the same time, the first access network device can also feedback the identification information of the first data that has been successfully sent / or unsuccessfully sent to the second access network device.

[0035] In a possible implementation manner, the method further includes: the first access network device sending third data to the second access network device, where the third data is the unsuccessfully sent unencrypted and integrity-protected data.

[0036] Through this implementation, the first access network device can continue to transmit the data that has not been successfully sent to the terminal device through the second access network device.

[0037] In a possible implementation, the method also includes: the first access network device can identify the first data through a first target identifier, and the first target identifier can be but is not limited to: an identifier of a first bearer, or an identifier of a first logical channel, or a first identifier carried in the first data, wherein the first identifier can be used to indicate which data belongs to the first data; the first bearer or the first logical channel is used to transmit the first data.

[0038] Through this implementation, the first access network device can effectively and accurately identify that the data from the second access network device is the first data, and then can accurately use the key of the first cell to process the first data.

[0039] In a third aspect, the present application provides a communication method, which can be executed by a second access network device or by a chip corresponding to the second access network device, without limitation. The method may specifically include: receiving first downlink data from a first access network device, and sending the first downlink data to a terminal device; and / or receiving first uplink data from the terminal device, and sending the first uplink data to the first access network device; wherein the first data is data encrypted and integrity protected using the secret key of the first cell.

[0040] In the embodiment of the present application, the first cell refers to the cell that the terminal device is currently connected to, and the terminal device communicates with the first access network device (e.g., a base station) through the first cell. The second cell is a cell that the terminal device is not currently connected to but is about to access, and the terminal device can communicate with the second access network device by accessing the second cell. In the above, the secret key of the first cell is deduced based on the configuration information of the secret key of the first cell.

[0041] In the solution of the present application, the second access network device can assist the terminal device in performing uplink and / or downlink first data transmission with the first access network device to reduce the duration of communication interruption when the terminal device performs cell switching.

[0042] In a possible implementation, the method also includes: the second access network device receives a first switching request message from the first access network device, the first switching request message including the address information of the user plane tunnel of the first access network device; the second access network device sends a first switching response message to the first access network device, the first switching response message including the address information of the user plane tunnel of the second access network device.

[0043] Through this implementation, accurate and effective data transmission between the second access network device and the first access network device can be ensured.

[0044] In a possible implementation, the first switching request information also includes third indication information, and the third indication information is used to request the second cell to use the configuration information of the first cell, and the first switching response information is used to indicate that the second cell confirms the use of the configuration information of the first cell; wherein the configuration information of the first cell includes the uplink physical layer channel configuration information of the first cell and the downlink physical layer channel configuration information of the first cell.

[0045] Through this implementation, the second cell can effectively use the same configuration information as the first cell, so that subsequent terminal devices can quickly and accurately access the second cell.

[0046] In a possible implementation, the second access network device sends the uplink first data to the first access network device, including: sending the uplink first data to the first access network device according to address information of the user plane tunnel of the first access network device.

[0047] Through this implementation, the second access network device can effectively and accurately send the uplink first data to the first access network device.

[0048] In a possible implementation, the method also includes: the second access network device receives uplink second data from the terminal device; uses the secret key of the second cell to decrypt and integrity check the uplink second data to obtain uplink data; sends the uplink data to the user plane function network element in the core network device; and / or receives downlink data from the user plane function network element in the core network device and / or the first access network device; uses the secret key of the second cell to encrypt and integrity protect the downlink data to obtain downlink second data; and sends the downlink second data to the terminal device.

[0049] In the above, the downlink data received by the second access network device from the first access network device may be data that the first access network device has not successfully sent to the terminal device.

[0050] Through this implementation, the second access network device can effectively and flexibly use the secret key of the second cell to process data from the terminal device, the core network device, and the first access network device, and perform corresponding data transmission.

[0051] In a possible implementation manner, the method further includes: after the first event, the second access network device sends a path switching request message to the access and mobility management function network element in the core network device; the path switching request message is used to request that the data transmission path be switched from the first path corresponding to the user plane function network element and the first access network device to the second path corresponding to the user plane function network element and the second access network device; the first event may be, but is not limited to, any one of the following:

[0052] (1) receiving the first downlink data from the first access network device; (2) receiving the first uplink data from the terminal device; (3) receiving the second uplink data from the terminal device.

[0053] Through this implementation, when the terminal device is communicating, the second access network device can be flexibly triggered to request the access and mobility management function network element in the core network to switch the path for transmitting data between the user function network element in the core network and the access network device.

[0054] In a possible implementation, the method also includes: the second access network device receives a path switching response message from the access and mobility management function network element, and obtains configuration information of the key of the second cell in the path switching response message; the path switching response message is used to indicate that the data transmission path has been switched from the first path to the second path.

[0055] Through this implementation, the second access network device can effectively obtain the configuration information of the secret key of the second cell from the access and mobility management function network element in the core network, and then the second access network device can use the configuration information of the secret key of the second cell to deduce the secret key of the second cell. The second access network device can also transmit the configuration information of the secret key of the second cell to the terminal device, so that the terminal device can effectively deduce the secret key of the second cell.

[0056] In a possible implementation, the method also includes: the second access network device sends a first indication message to the terminal device, and sends a second indication message to the first access network device; wherein the first indication message is used to instruct the terminal device to perform one or more of the following: stop using the key of the first cell to process data, delete the key of the first cell, stop processing associated with the key of the first cell, release the first bearer or first logical channel of the first data, and stop carrying the second identifier in the second data; the second indication message is used to instruct the first cell or the first access network device to stop generating or sending the first data and release the first bearer or first logical channel of the first data.

[0057] Through this implementation, the terminal device and the first access network device (or the first cell) stop the processing operations associated with the key of the first cell, and no longer use the key of the first cell to process data and communications.

[0058] In a possible implementation, the method further includes: the second access network device receiving first status information from the first access network device, the first status information being used to indicate identification information (eg, a serial number) of the first data that has been successfully sent and / or unsuccessfully sent.

[0059] Through this implementation, the second access network device can learn the first data that has been successfully sent and / or unsuccessfully sent by the first access network device.

[0060] In a possible implementation manner, the method further includes: the second access network device receiving third data from the first access network device, where the third data is the unsuccessfully sent unencrypted and integrity-protected data.

[0061] Through this implementation, the second access network device can continue to send the data that the first access network device has not successfully sent to the terminal device.

[0062] In a possible implementation, the method also includes: the second access network device identifies the first data through a first target identifier, and the first target identifier may be but is not limited to: an identifier of a first bearer, or an identifier of a first logical channel, or a first identifier carried in the first data; the first bearer or the first logical channel is used to transmit the first data; the second access network device identifies the second data through a second target identifier, and the second target identifier may be but is not limited to: an identifier of a second bearer, or an identifier of a second logical channel, or a first identifier carried in the second data; the second bearer or the second logical channel is used to transmit the second data.

[0063] Through this implementation, the second access network device can effectively and accurately identify the first data and the second data, and then for the first data and the second data, the second access network device can accurately determine the object to be sent for transmission.

[0064] In a fourth aspect, an embodiment of the present application also provides a communication device, which can be used to execute the method of the first aspect. The device may be a terminal device, or the device may be a component in the terminal device (for example, a chip, or a chip system, or a circuit), or may be a device that can be used in combination with the terminal device.

[0065] In one possible implementation, the device may include a module or unit corresponding to the method / operation / step / action described in the first aspect, and the module or unit may be a hardware circuit, or software, or a combination of a hardware circuit and software. In one possible implementation, the device may include a processing unit (also referred to as a processing module) and a communication unit (also referred to as a communication module), wherein the communication unit may be used to perform the functions of receiving and / or sending, and the processing unit may be used to perform the method described in the first aspect or any possible implementation of the first aspect.

[0066] In the fifth aspect, an embodiment of the present application also provides a communication device, which can be used to execute the method of the second aspect. The device may be a first access network device, or the device may be a component in the first access network device (for example, a chip, or a chip system, or a circuit), or may be a device that can be used in combination with the first access network device.

[0067] In one possible implementation, the device may include a module or unit corresponding to the method / operation / step / action described in the second aspect, and the module or unit may be a hardware circuit, or software, or a combination of a hardware circuit and software. In one possible implementation, the device may include a processing unit (also referred to as a processing module) and a communication unit (also referred to as a communication module), wherein the communication unit may be used to perform the functions of receiving and / or sending, and the processing unit may be used to perform the method described in the second aspect or any possible implementation of the second aspect.

[0068] In the sixth aspect, an embodiment of the present application also provides a communication device, which can be used to execute the method of the third aspect. The device may be a second access network device, or the device may be a component in the second access network device (for example, a chip, or a chip system, or a circuit), or may be a device that can be used in combination with the second access network device.

[0069] In one possible implementation, the device may include a module or unit corresponding to the method / operation / step / action described in the third aspect, and the module or unit may be a hardware circuit, or software, or a combination of a hardware circuit and software. In one possible implementation, the device may include a processing unit (also referred to as a processing module) and a communication unit (also referred to as a communication module), wherein the communication unit may be used to perform the functions of receiving and / or sending, and the processing unit may be used to perform the method described in the third aspect or any possible implementation of the third aspect.

[0070] In the seventh aspect, an embodiment of the present application provides a device, which includes: at least one processor and a communication interface; wherein the communication interface is used to communicate with other devices; the processor is used to run a set of programs so that the device can implement the method provided in the above-mentioned first aspect or any possible implementation method thereof.

[0071] In the eighth aspect, an embodiment of the present application provides a device, which includes: at least one processor and a communication interface; wherein the communication interface is used to communicate with other devices; the processor is used to run a set of programs so that the device can implement the method provided in the above-mentioned second aspect or any possible implementation method thereof.

[0072] In the ninth aspect, an embodiment of the present application provides a device, which includes: at least one processor and a communication interface; wherein the communication interface is used to communicate with other devices; the processor is used to run a set of programs so that the device can implement the method provided in the third aspect above or any possible implementation method thereof.

[0073] In the tenth aspect, an embodiment of the present application also provides a computer storage medium, which stores a software program. When the software program is read and executed by one or more processors, it can implement the method provided by the above-mentioned first aspect or any possible implementation method thereof, or implement the method provided by the above-mentioned second aspect or any possible implementation method thereof, or implement the method provided by the above-mentioned third aspect or any possible implementation method thereof.

[0074] In the eleventh aspect, an embodiment of the present application also provides a computer program product comprising instructions, which, when executed on a computer, enables the method provided by the first aspect or any possible implementation thereof to be executed, or enables the method provided by the second aspect or any possible implementation thereof to be executed, or enables the method provided by the third aspect or any possible implementation thereof to be executed.

[0075] In the twelfth aspect, an embodiment of the present application provides a communication system, including a terminal device capable of implementing the method provided in the first aspect, a first access network device capable of implementing the method provided in the second aspect, and a second access network device capable of implementing the method provided in the third aspect.

[0076] In the thirteenth aspect, an embodiment of the present application also provides a chip system, which includes a processor for supporting a terminal device to implement the functions involved in the first aspect above; or for supporting a first access network device to implement the functions involved in the second aspect above; or for supporting a second access network device to implement the functions involved in the third aspect above.

[0077] In a possible design, the chip system further includes a memory, which is used to store necessary program instructions and data executed by the loading device. The chip system can be composed of chips or include chips and other discrete devices.

[0078] It should be noted that the technical effects that can be achieved by any possible implementation method of the above-mentioned fourth to thirteenth aspects or the fourth to thirteenth aspects can be correspondingly referred to the technical effects that can be achieved by any possible implementation method of the above-mentioned first to third aspects or the first to third aspects; they will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Figure 1A A schematic diagram of a mobile communication system to which the embodiments of the present application can be applied;

[0080] Figure 1B A schematic diagram of a network architecture applicable to embodiments of the present application;

[0081] Figure 2 A schematic diagram of the structure of a distributed base station provided in an embodiment of the present application;

[0082] Figure 3 A flow chart of a communication method provided in an embodiment of the present application;

[0083] Figure 4 A specific flow chart of the first embodiment provided in the embodiments of the present application;

[0084] Figure 5 A specific flow chart of the second embodiment provided in the embodiments of the present application;

[0085] Fig. 6A A schematic diagram of a downlink transmission path provided in an embodiment of the present application;

[0086] Figure 6B A schematic diagram of a downlink transmission path provided in an embodiment of the present application;

[0087] Figure 7 A specific flow chart of the third embodiment provided in the embodiments of the present application;

[0088] Figure 8 A schematic diagram of the structure of a communication device provided in an embodiment of the present application;

[0089] Fig. 9 A schematic diagram of the structure of another communication device provided in an embodiment of the present application;

[0090] Fig.10 A schematic diagram of the structure of a chip provided in an embodiment of the present application. DETAILED DESCRIPTION

[0091] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. The terms used in the following embodiments are only for the purpose of describing specific embodiments and are not intended to be used as limitations on the present application. As used in the specification and the appended claims of the present application, the singular expressions "one", "a kind", "said", "above", "the" are intended to also include expressions such as "one or more", unless there is a clear contrary indication in the context. It should also be understood that in the embodiments of the present application, "one or more" refers to one, two or more; "and / or" describes the association relationship of associated objects, indicating that three relationships may exist; for example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the objects associated before and after are in an "or" relationship.

[0092] References to "one embodiment" or "some embodiments" described in this specification mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. The terms "including", "comprising", "having" and their variations involved in this application all mean "including but not limited to", unless otherwise specifically emphasized in other ways. Words such as "exemplary" or "for example" are used to indicate examples, illustrations or descriptions, and any embodiment or design described as "exemplary" or "for example" should not be interpreted as being more preferred or more advantageous than other embodiments or designs. The use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way for easy understanding.

[0093] The multiple involved in the embodiments of the present application refers to greater than or equal to two. It should be noted that in the description of the embodiments of the present application, words such as "first" and "second", or numbers such as "1" and "2", are only used to distinguish the purpose of description, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order. In addition, the term "used to indicate" mentioned in the description of the embodiments of the present application can include being used for direct indication and being used for indirect indication. When describing that a certain indication information is used to indicate A, it can include that the indication information directly indicates A or indirectly indicates A, and it does not mean that the indication information must carry A.

[0094] The term "switching" involved in the embodiments of the present application can be understood as updating, replacing or changing. For example, the path switching of the UE can refer to updating or replacing the source path of the UE with the new path after determining the new path of the UE, so that the UE communicates through the new path. Therefore, the term "switching" can also be replaced by "updating" and other words accordingly, and the present application does not limit this.

[0095] In order to better understand the embodiments of the present application, the application scenarios and existing problems of the embodiments of the present application are first introduced below. It should be noted that the application scenarios are intended to make the embodiments of the present application easier to understand and should not be regarded as limiting the scope of protection claimed by the present application.

[0096] In a mobile communication system, the communication link between the terminal device and the access network device changes due to the movement of the terminal. The access network device will instruct the terminal device to switch cells according to the movement of the terminal device. In the process of switching from the source cell to the target cell, the terminal device needs to use the new key of the target base station to encrypt the data and signaling before communicating with the target base station. Since the security encryption function is located in the packet data convergence protocol (PDCP) layer, the terminal device needs to perform the derivation of the new key and the PDCP re-establishment process after receiving the switching command. This processing time will cause communication interruption during the switching process, affecting the user experience.

[0097] In view of the above problems, the present application provides a communication method, which can ensure that the duration of communication interruption when a terminal device performs cell switching is short.

[0098] The technical solutions of the embodiments of the present application can be applied to various communication systems, for example: wideband code division multiple access (WCDMA) system, general packet radio service (GPRS), long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), universal mobile telecommunication system (UMTS), worldwide interoperability for microwave access (WiMAX) communication system, fifth generation (5G) system or future sixth generation communication system, etc.

[0099] Figure 1A FIG. 1 is a schematic diagram of a communication system 1000 architecture to which the embodiments of the present application can be applied. Figure 1AAs shown, the communication system includes a wireless access network 100 and a core network 200. Optionally, the communication system 1000 may also include the Internet 300. The wireless access network 100 may include at least one access network device (such as Figure 1A 110a and 110b), and may further include at least one terminal (such as Figure 1A 120a-120j in the figure). The terminal is connected to the access network device by wireless means, and the access network device is connected to the core network by wireless or wired means. The core network device and the access network device can be independent and different physical devices, or the functions of the core network device and the logical functions of the access network device can be integrated on the same physical device, or the functions of some core network devices and some access network devices can be integrated on one physical device. Terminals and access network devices can be connected to each other by wired or wireless means. Figure 1A This is just a schematic diagram. The communication system may also include other network devices, such as wireless relay devices and wireless backhaul devices. Figure 1A Not drawn in.

[0100] refer to Figure 1B As shown, the core network equipment includes session management network elements, access management network elements, user plane function network elements, etc.

[0101] Among them, the session management network element is mainly used for session management, allocation and management of the Internet Protocol (IP) address of the terminal equipment, selection of manageable user equipment plane functions, policy control, or termination points of the charging function interface, and downlink data notification. In 5G communication, the session management network element can be a session management function (SMF) network element. In future communications such as 6G communication, the session management function network element can still be an SMF network element, or have other names, which is not limited in this application. Nsmf is a service-based interface provided by SMF. SMF can communicate with other network functions through Nsmf.

[0102] Access management network element: mainly used for mobility management and access management, etc. For example, it can be the mobility management entity (MME) function in the 4G communication network or the access and mobility management function (AMF) network element in the 5G network. In future communications such as 6G communications, the access management network element can still be an AMF network element, or have other names, which is not limited in this application. Namf is a service-based interface provided by AMF. AMF can communicate with other network functions through Namf.

[0103] User plane function network element: used for packet routing and forwarding, or quality of service (QoS) processing of user plane data. In 5G communication, the user plane network element can be a user plane function (UPF) network element. In future communications such as 6G communication, the user plane network element can still be a UPF network element, or have other names, which is not limited in this application. Figure 1B It is only an example of a network architecture that can be adapted by the embodiments of the present application, which also includes other network elements (or devices). For a specific introduction, please refer to the existing technology and will not be described in detail here.

[0104] The access network device may be a base station, an evolved NodeB (eNodeB), a transmission reception point (TRP), a next generation NodeB (gNB) in a fifth generation (5G) mobile communication system, a base station in a sixth generation (6G) mobile communication system, a base station in a future mobile communication system, or an access node in a wireless fidelity (WiFi) system, etc.; it may also be a module or unit that completes part of the functions of a base station, for example, a centralized unit (CU) or a distributed unit (DU). The access network device may be a macro base station, a micro base station or an indoor station, a relay node or a donor node, etc. The embodiments of the present application do not limit the specific technology and specific device form adopted by the access network device. In the embodiments of the present application, a base station is described as an example of an access network device.

[0105] In one possible implementation, some functions of the access network equipment are deployed in a CU, and the remaining functions are deployed in the DU. Multiple DUs are shared or connected to one CU, which can save costs and facilitate network expansion. The division of CU and DU can be divided according to the protocol stack. One possible way is to deploy the radio resource control (RRC), service data adaptation protocol (SDAP) and packet data convergence protocol (PDCP) layers in the CU, and the remaining radio link control (RLC) layer, media access control (MAC) layer and physical layer (PHYsical, PHY) in the DU. The CU and DU are connected through the F1 interface. The CU represents the gNB connected to the core network through the NG interface, the CU represents the gNB connected to other gNBs through the Xn interface, and the CU can also represent the gNB to perform dual connection operations with other eNBs through the X2 port. The details are as follows Figure 2 As shown. Further, the CU includes a central unit control plane (CU-CP) and a central unit user plane (CU-UP). CU-UP and CU-CP may be on the same physical device or on different physical devices. CU-CP and CU-UP are connected through an interface (e.g., E1 interface). CU-CP represents the base station and is connected to the core network through an interface (e.g., Ng interface). CU-CP is connected to DU through an interface (e.g., F1-C interface), and CU-UP is connected to DU through an interface (e.g., F1-U interface). The number of CU-CPs may be one, and the number of CU-UPs may be one or more. Multiple CU-UPs may share one CU-CP. CU-CP mainly has control plane functions. CU-UP mainly has user plane functions. One possible implementation method is: for 5G base stations, the RRC layer may be deployed on the CU-CP, while the SDAP layer is not deployed on the CU-CP. CU-CP may also have some control plane functions of the PDCP layer, such as processing of signaling radio bearers (SRBs). The SDAP layer can be deployed in the CU-UP, but the RRC layer is not deployed in the CU-UP. The CU-UP can also have some user plane functions of the PDCP layer, such as processing data radio bearers (DRBs).

[0106] It should be noted that in different systems, CU (or CU-CP and CU-UP), or DU may have different names, but those skilled in the art can understand their meanings. For example, in an open radio access network (O-RAN) system, CU may also be referred to as O-CU (open CU), DU may also be referred to as O-DU, CU-CP may also be referred to as O-CU-CP, CU-UP may also be referred to as O-CU-UP, and RU may also be referred to as O-RU. For the convenience of description, this application takes CU, CU-CP, CU-UP, DU and RU as examples for description. Any unit in the CU (or CU-CP and CU-UP), DU and RU in this application may be implemented by a software module, a hardware module, or a combination of a software module and a hardware module.

[0107] The terminal may also be referred to as a terminal device, user equipment (UE), mobile station, mobile terminal, etc. The terminal can be widely used in various scenarios, for example, device-to-device (D2D), vehicle-to-everything (V2X) communication, machine-type communication (MTC), Internet of Things (IOT), virtual reality, augmented reality, industrial control, automatic driving, telemedicine, smart grid, smart furniture, smart office, smart wear, smart transportation, smart city, etc. The terminal may be a mobile phone, a tablet computer, a computer with wireless transceiver function, a wearable device, a vehicle, a drone, a helicopter, an airplane, a ship, a robot, a mechanical arm, a smart home device, etc. The embodiments of the present application do not limit the specific technology and specific device form adopted by the terminal device.

[0108] The access network equipment and UE can be fixed or movable. The access network equipment and UE can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; they can also be deployed on the water surface; they can also be deployed on aircraft, balloons and artificial satellites in the air, and the embodiments of the present application are not limited to this. In addition, the access network equipment and UE, the access network equipment and the access network equipment, and the UE and the UE can communicate through the authorized spectrum, or through the unauthorized spectrum, or through the authorized spectrum and the unauthorized spectrum at the same time; they can communicate through the spectrum below 6 gigahertz (GHz), or through the spectrum above 6 GHz, and can also use the spectrum below 6 GHz and the spectrum above 6 GHz at the same time. The embodiments of the present application do not limit the spectrum resources used for wireless communications.

[0109] In the embodiments of the present application, the functions of the access network device may also be performed by a module (such as a chip) in the access network device, or by a control subsystem including the functions of the access network device. The control subsystem including the functions of the access network device here may be a control center in the above-mentioned application scenarios such as smart grid, industrial control, smart transportation, and smart city. The functions of the terminal device may also be performed by a module (such as a chip or a modem) in the terminal device, or by a device including the functions of the terminal device.

[0110] In this application, the access network device sends a downlink signal / information / data to the terminal device, and the downlink information / / data can be carried on but not limited to the downlink channel; the terminal device sends an uplink signal / information / data to the access network device, and the uplink information / data can be carried on but not limited to the uplink channel. In order to communicate with the access network device, the terminal device needs to establish a wireless connection with the cell under the jurisdiction (control) of the access network device. The cell that has established a wireless connection with the terminal device is called the service cell of the terminal device.

[0111] The technical solution of the present application is introduced below in conjunction with specific embodiments.

[0112] The present invention provides a communication method which is applicable to but not limited to Figure 1A-1B The communication system shown. The method can be executed by the terminal device, the first access network device, and the second access network device; or the method can be executed by the components (modules, chips, etc.) corresponding to the terminal device, the first access network device, and the second access network device; or the method can be executed by a device corresponding to the terminal device, the first access network device, and the second access network device. The embodiments of the present application do not specifically limit the specific forms and quantities of the terminal device, the first access network device, and the second access network device. Please refer to Figure 3 As shown, the specific process of this method is as follows:

[0113] S301: A first access network device sends a first handover message to a terminal device, the first handover message being used to instruct the terminal device to handover from a first cell currently located to a second cell, the second cell being a cell under the jurisdiction of the second access network device. Correspondingly, the terminal device receives the first handover message from the first access network device.

[0114] In the embodiment of the present application, the first cell refers to the cell that the terminal device is currently connected to, and the terminal device communicates with the first access network device (such as a base station) through the first cell. The second cell is a cell that the terminal device is not currently connected to but is about to access, and the terminal device can communicate with the second access network device by accessing the second cell.

[0115] Optionally, the first switching message includes cell configuration indication information, where the cell configuration indication information is used to indicate that the second cell uses the same configuration information as the first cell (ie, the configuration information of the first cell).

[0116] In one implementation, before the first access network device sends the first switching message to the terminal device, it also includes: the first access network device sends a first switching request message to the second access network device, and the first switching request message includes the address information of the user plane tunnel of the first access network device. In this way, the second access network device can obtain the address information of the user plane tunnel of the first access network device by receiving the first switching request message, so that the second access network device can accurately transmit data with the first access network device according to the address information of the user plane tunnel of the first access network device.

[0117] Correspondingly, after receiving the first switching request information, the second access network device will send a first switching response information to the first access network device, and the first switching response information includes the address information of the user plane tunnel of the second access network device. In this way, the first access network device can obtain the address information of the user plane tunnel of the second access network device through the received first switching response information, so that data can be accurately transmitted with the second access network device according to the address information of the user plane tunnel of the second access network device.

[0118] In an embodiment of the present application, the address information of the user plane tunnel of the first access network device or the second access network device may include the address information of the uplink user plane tunnel and / or the address information of the downlink user plane tunnel. Exemplarily, the address information of the user plane tunnel includes a transport layer address and a tunnel endpoint identifier of a general packet radio service GPRS tunneling protocol (GPRS tunneling protocol, GTP).

[0119] In one embodiment, the first switching request message carries the secret key of the second cell and the configuration information of the secret key of the second cell; and the first switching response message fed back by the second access network device to the first access network device also carries the secret key configuration information of the second cell. After receiving the first switching response message, the first access network device carries the configuration information of the secret key of the second cell in the first switching message and sends it to the terminal device, so that the terminal device can subsequently deduce the secret key of the second cell. In this embodiment, the first access network device generates the configuration information of the secret key of the second cell, deduces the secret key of the second cell, and then sends the secret key of the second cell and the secret key configuration information of the second cell to the second access network device for use and transmission in subsequent steps.

[0120] In a possible implementation, the first switching request information also includes third indication information, and the third indication information is used to request the second cell to use the configuration information of the first cell. Correspondingly, the first switching response information can be used to indicate that the second cell confirms to use the configuration information of the first cell. The configuration information of the first cell may include but is not limited to the uplink or downlink physical layer channel configuration information of the first cell. For example, frequency domain bandwidth, cell-radio network temporary identifier (C-RNTI), etc.

[0121] Through the above-mentioned interaction between the first access network device and the second access network device, the second cell and the first cell can use the same configuration information, so that the terminal device can subsequently access the second cell accurately and quickly.

[0122] S302: Based on the first switching message, the terminal device uses the secret key of the first cell to perform first data transmission with the second access network device.

[0123] In the embodiment of the present application, the secret key of the first cell can be deduced according to the configuration information of the secret key of the first cell.

[0124] In a possible implementation, the terminal device uses the secret key of the first cell to perform first data transmission with the second access network device, which may include: the terminal device uses the secret key of the first cell to perform first data transmission with the second access network device after establishing a communication connection with the second cell and without deducing the secret key of the second cell.

[0125] In a possible implementation, if the first switching request information mentioned above does not carry the key of the second cell and the configuration information of the key of the second cell (that is, the key of the second cell and the configuration information of the key of the second cell are not generated and deduced by the first access network device), then the first switching response information and the first switching message mentioned above will not carry the configuration information of the key of the second cell; in this case, the terminal device can receive the configuration information of the key of the second cell from the second access network device after establishing a communication connection with the second cell; and the configuration information of the key of the second cell can be obtained by the second access network device from the access and mobility management function network element in the core network.

[0126] In an embodiment of the present application, establishing a communication connection between the terminal device and the second cell may include: establishing a bearer (or logical channel) for transmitting first data and a bearer (or logical channel) for transmitting second data between the terminal device and the second cell.

[0127] S303: The first access network device uses the secret key of the first cell to perform first data transmission with the second access network device.

[0128] In one embodiment, before the first access network device uses the secret key of the first cell to perform first data transmission with the second access network device, the method also includes: the first access network device receives a first response message (for example, an RLC ACK message, or a hybrid automatic repeat request (HARQ) confirmation (ACK) message, or an RRC message, a media access control MAC control element (CE), etc.) from the terminal device, and the first response message is used to notify the terminal device to confirm the switching from the first cell to the second cell.

[0129] In the embodiment of the present application, the above steps S302 and S303 are the process of exchanging the first data between three parties (i.e., the terminal device, the first access network device, and the second access network device). Therefore, the execution order of the steps S302 and S303 is not specifically limited. With respect to the above S302 in which the terminal device uses the secret key of the first cell to perform the first data transmission with the second access network device and S303 in which the first access network device uses the secret key of the first cell to perform the first data transmission with the second access network device, the specific interaction process is as follows:

[0130] Uplink transmission: In step S302, the terminal device uses the secret key of the first cell to encrypt and integrity-protect the uplink data to obtain the first uplink data; the first uplink data is sent to the second access network device; accordingly, the second access network device receives the first uplink data from the terminal device. In step S303, the second access network device can send the first uplink data to the first access network device according to the address information of the user plane tunnel of the first access network device; accordingly, after receiving the first uplink data from the second access network device, the first access network device uses the secret key of the first cell to decrypt and integrity-check the first uplink data to obtain the uplink data.

[0131] Downlink transmission: In step S303, the first access network device uses the secret key of the first cell to encrypt and integrity protect the downlink data to obtain the first downlink data; according to the address information of the user plane tunnel of the second access network device, the first downlink data is sent to the second access network device; in step S302, the second access network device sends the first downlink data to the terminal device, and then the terminal device uses the secret key of the first cell to decrypt and integrity check the first downlink data to obtain the downlink data.

[0132] In an embodiment of the present application, the terminal device or the first access network device or the second access network device can identify the received first data through a first target identifier, and identify the received second data through a second target identifier. The first target identifier may be, but is not limited to: an identifier of a first bearer, an identifier of a first logical channel, a first identifier carried in the first data; wherein the first bearer or the first logical channel is used to transmit the first data, and the first identifier is used to indicate which data belongs to the first data. The second target identifier may be, but is not limited to: an identifier of a second bearer, an identifier of a second logical channel, or a second identifier carried in the second data; wherein the second bearer or the second logical channel is used to transmit the second data, and the second identifier is used to indicate which data belongs to the second data.

[0133] It should be noted that in the embodiment of the present application, after the terminal device establishes a communication connection with the second cell and has not deduced the secret key of the second cell, the above-mentioned uplink transmission and / or downlink transmission can be performed.

[0134] S304: The terminal device uses the secret key of the second cell to perform second data transmission with the second access network device.

[0135] In a possible implementation, after the terminal device derives the secret key of the second cell, it executes step S304.

[0136] In the embodiment of the present application, when the terminal device executes step S304, it may specifically include the following:

[0137] The terminal device uses the secret key of the second cell to encrypt and perform integrity protection processing on the uplink data to obtain uplink second data, and then sends the uplink second data to the second access network device; after receiving the uplink second data from the terminal device, the second access network device uses the secret key of the second cell to perform decryption and integrity verification processing on the uplink second data to obtain the uplink data; further, the second access network device sends the uplink data to the user plane function network element in the core network device; and / or

[0138] The second access network device receives downlink data from the user plane functional network element in the core network device and / or the first access network device, and then uses the secret key of the second cell to encrypt and integrity protect the downlink data to obtain downlink second data; further, the second access network device sends the downlink second data to the terminal device; after the terminal device receives the downlink second data from the second access network device, it can use the secret key of the second cell to decrypt and integrity check the downlink second data.

[0139] In an embodiment of the present application, the terminal device or the second access network device can identify the received second data through a second target identifier, and the second target identifier can be but is not limited to: an identifier of a second bearer, or a second logical channel identifier, a second identifier carried in the second data; wherein, the second bearer or the second logical channel is used to transmit the second data.

[0140] In an embodiment of the present application, the second access network device may send a path switching request message to the access and mobility management function network element in the core network device after the first event; the path switching request message is used to request that the data transmission path be switched from the first path corresponding to the user plane function network element and the first access network device to the second path corresponding to the user plane function network element and the second access network device; wherein the first event may be any one of the following:

[0141] (1) The second access network device receives downlink first data from the first access network device; (2) The second access network device receives uplink first data from the terminal device; (3) The second access network device receives the uplink second data from the terminal device.

[0142] The above (1) and (2) may be steps in the above step S303 in which the terminal device performs the first data transmission with the first access network device via the second access network device.

[0143] In a possible implementation, the method further includes: the second access network device receives a path switching response message from the access and mobility management function network element, and obtains configuration information of the key of the second cell in the path switching response message; the path switching response message is used to indicate that the data transmission path has been switched from the first path to the second path.

[0144] After the second access network device receives the configuration information of the secret key of the second cell from the core network device (access and mobility management function network element), it can further send the configuration information of the secret key of the second cell to the terminal device when the terminal device has established a communication connection with the second cell, so that the terminal device can effectively and accurately deduce the secret key of the second cell based on the configuration information of the secret key of the second cell.

[0145] In one implementation, after receiving the path switching response information, the second access network device further executes: sending first indication information to the terminal device, and sending second indication information to the first access network device.

[0146] In the above, the first indication information is used to instruct the terminal device to execute but not limited to: stop using the key of the first cell to process data, delete the key of the first cell, stop processing associated with the key of the first cell, release the first bearer or first logical channel of the first data, and stop carrying the second identifier in the second data.

[0147] The second indication information is used to instruct the first cell or the first access network device to stop generating or sending the first data and release the first bearer or first logical channel of the first data.

[0148] In addition, optionally, after receiving the second indication information sent by the second access network device, the first access network device sends first status information to the second access network device, and the first status information is used to indicate identification information of the first data that has been successfully sent and / or unsuccessfully sent, such as a serial number.

[0149] Optionally, the first access network device further sends third data to the second access network device, where the third data is the unencrypted and integrity-protected data that was not successfully sent.

[0150] In an embodiment of the present application, the payload of the third data may be the same as the payload of the first data that was previously sent by the first access network device but was not successfully received by the terminal device.

[0151] In an embodiment of the present application, the above-mentioned first data may refer to data obtained after encryption and integrity protection processing using the secret key of the first cell, and the second data may refer to data obtained after encryption and integrity protection processing using the secret key of the second cell. In other embodiments or application scenarios, the first data may also refer to data obtained after processing using other privacy information associated with the first cell, and the second data may also refer to data obtained after processing by other privacy information associated with the second cell. Then, the "secret key of the first cell" in the full text can be replaced with other privacy information associated with the first cell, and the "secret key of the second cell" can be replaced with other privacy information associated with the second cell. The process of key deduction can be implemented by referring to the deduction process of "secret key of the first cell" and "secret key of the second cell".

[0152] The embodiment of the present application proposes a communication method and device, the method comprising: a terminal device receives a first switching message from a first access network device, the first switching message is used to instruct the terminal device to switch from the first cell currently located to the second cell, the second cell being a cell under the jurisdiction of the second access network device; the terminal device uses the secret key of the first cell to perform first data transmission with the second access network device based on the first switching message. Through this method, it can be ensured that the duration of communication interruption when the terminal device performs cell switching is short, or the duration of communication interruption when the terminal device performs cell switching can be reduced.

[0153] Based on the above Figure 3 A communication method is shown, and is further described in detail below through several specific embodiments.

[0154] Embodiment 1:

[0155] In the first embodiment, for the scenario of UE switching base stations (or UE switching cells), taking UE1 as an example, UE1 switches from the source base station S-gNB (which can also be the source cell) to the target base station T-gNB (which can also be the target cell). Before UE1 switches, the user data exchanged between UPF and UE1 (that is, UE1 sends user data to UPF, and UPF sends user data to UE1) is forwarded via the source base station (S-gNB); after UE1 switches, the user data exchanged between UPF and UE1 is forwarded via the target base station (T-gNB). This first embodiment mainly introduces the communication during the switching process of UE1, see Figure 4 As shown, the process of this embodiment 1 is as follows:

[0156] S401: S-gNB sends a handover request message to T-gNB.

[0157] Correspondingly, the T-gNB receives the handover request message from the S-gNB. The handover request message includes the address information of the uplink user plane tunnel of the S-gNB. In this way, the subsequent T-gNB can send uplink data to the S-gNB according to the address information of the uplink user plane tunnel of the S-gNB. In addition, the handover request message also includes the key parameters of the target cell, such as the next hop chain calculation value. The handover request message also includes the key of the target cell, which is derived by the S-gNB based on the key parameters of the target cell.

[0158] The handover request message may also be called a handover preparation message, which is used to request the configuration information of the target cell from the T-gNB.

[0159] Optionally, the handover request message may further include first configuration information of the source cell, and request the target cell to use configuration information that is the same as the first configuration information.

[0160] Exemplarily, the handover request message is used to request the target cell to use the same physical layer channel configuration information (ie, uplink physical layer channel configuration information and downlink physical layer channel configuration information) as the source cell, such as frequency domain bandwidth, cell radio network temporary identifier C-RNTI, etc.

[0161] In the embodiment of the present application, the first configuration information refers to various configuration information that UE1 can reuse in different cells (such as the source cell and the target cell), including but not limited to the above-mentioned physical channel configuration information. However, the source cell and the target cell usually cannot use the same cell identifier or key and other information, so information such as the cell identifier or key does not belong to the scope of the first configuration information.

[0162] In the above, the source cell is a cell managed (or governed / controlled) by the S-gNB, UE1 is currently connected to the source cell, and communicates with the S-gNB through the source cell. The target cell is a cell managed (or governed / controlled) by the T-gNB, at this time, UE1 has not yet accessed the target cell, and UE1 will communicate with the T-gNB through the target cell in the future.

[0163] In the embodiment of the present application, when UE1 switches base stations (or cells), if S-gNB has provided UE1 with multiple candidate cells and configuration information of the multiple candidate cells in advance, then the target cell can be one of the multiple candidate cells. If S-gNB has not provided UE1 with multiple candidate cells in advance, then the target cell is an accessible cell temporarily determined by S-gNB for UE1. Therefore, this embodiment can be applied to scenarios where multiple candidate cells are pre-configured for UE1, and can also be applied to scenarios where multiple candidate cells are not pre-configured for UE1.

[0164] S402: T-gNB sends a handover request response message to S-gNB.

[0165] Correspondingly, the S-gNB receives the handover request response message from the T-gNB. The handover request response message includes the address information of the downlink user plane tunnel of the T-gNB. In this way, the subsequent S-gNB can send downlink data to the T-gNB according to the address information of the downlink user plane tunnel of the T-gNB.

[0166] Exemplarily, the address information of the user plane tunnel in the above S401 and S402 can be Xn-U user plane tunnel address information or F1-U user plane tunnel address information; wherein, the Xn interface is the interface name between gNB and gNB, and the F1 interface is the interface name between CU and DU under the CU-DU separation architecture.

[0167] The handover request response message also includes configuration information of the target cell encapsulating the key parameters of the target cell.

[0168] If the target cell uses the same first configuration information as the source cell, the configuration information of the target cell does not include the first configuration information. If the target cell does not use the same first configuration information as the source cell, the configuration information of the target cell includes the first configuration information.

[0169] Exemplarily, the key parameter of the target cell may be a next hop chaining count (NCC) value.

[0170] Optionally, the handover request response message includes indication information 0, where the indication information 0 is used to indicate whether the target cell agrees to use the same first configuration information as that of the source cell.

[0171] If the target cell does not agree to use the same first configuration information as the source cell, and the S-gNB side does not provide UE1 with the configuration information of multiple candidate cells (including the target cell) in advance, then the configuration information of the target cell carried in the switching request response message also includes the first configuration information.

[0172] S403: S-gNB sends a first switching command to UE1, where the first switching command is used to request UE1 to switch from the source cell to the target cell.

[0173] Correspondingly, the UE1 receives the first switching command sent by the S-gNB through the source cell. The first switching command includes the key parameter of the target cell.

[0174] After receiving the first handover command, UE1 does not re-establish PDCP when no connection is established with the target cell, but retains the key of the source cell. In addition, after UE1 receives the first handover command, when subsequently sending data, the bearer (or logical channel) corresponding to the data carries an identifier that can indicate the data type, or carries identification information that can indicate the data type in the sent data.

[0175] Optionally, the first handover command carries configuration indication information, and the configuration indication information is used to indicate that the target cell uses the same first configuration information as the source cell. Corresponding to the above S402, if the target cell does not use the same first configuration information as the source cell, and the S-gNB does not provide UE1 with configuration information of multiple candidate cells (including the target cell) in advance, then the first handover command can carry the configuration information of the target cell.

[0176] In the embodiment of the present application, after receiving the first switching command, UE1 may execute the following steps S404 and S405.

[0177] S404: UE1 sends a first response message to S-gNB.

[0178] The first response message is used to notify the S-gNB that the UE1 accepts the handover from the source cell to the target cell, or to notify the S-gNB that the UE1 has received the first handover command, which is not limited in this embodiment of the present application. The first response message can be: RLC ACK message, or HARQ ACK message, or RRC message, MAC CE, etc.

[0179] After receiving the first response message sent by UE1, S-gNB suspends using the air interface communication link of the source cell to communicate with UE1.

[0180] S405: UE1 executes a processing flow based on the handover command.

[0181] In step S405, the processing flow executed by UE1 may specifically include but is not limited to one or more of the following steps:

[0182] (1) UE1 establishes a connection with the target cell;

[0183] (2) Configuration information of the effective target cell;

[0184] If the target cell uses the same configuration information as the source cell (i.e., the first configuration information), then in step (2), UE1 can maintain the first configuration information of the source cell. If the target cell does not use the same configuration information as the source cell (i.e., the first configuration information), then in step (2), UE1 can validate the configuration information of the target cell.

[0185] (3) Baseband adjustment for the target cell;

[0186] (4) Adjust the radio frequency unit for the target cell;

[0187] (5) deduce the secret key of the target cell;

[0188] (6) Use the target cell’s secret key to encrypt and integrity protect the data.

[0189] In the above, the step of establishing a connection between UE1 and the target cell may include establishing a bearer / logical channel for transmitting data between UE1 and the target cell, and may also include establishing an air interface link, such as establishing a random access or random access-free target cell air interface connection.

[0190] When the target cell confirms to use the same first configuration information as the source cell, UE1 will maintain the hardware processing flow corresponding to the first configuration information, such as maintaining baseband processing, maintaining radio frequency unit processing, etc., which is conducive to UE1 quickly completing the connection establishment of the target cell.

[0191] Usually, the above steps (1) to (4) are performed first, and (5) and (6) are performed later, and steps (5) and (6) are equivalent to the process of UE1 re-establishing PDCP. The embodiment of the present application does not specifically limit the execution order of steps (1) to (4).

[0192] After the steps related to UE1 establishing a connection with the target cell in S405 are completed, the following S406A-S406B, and / or S407A-S407B may be executed.

[0193] S406A: The S-gNB sends the first type of downlink data to the T-gNB.

[0194] The S-gNB may send the first type of downlink data to the T-gNB according to the address information of the downlink user plane tunnel of the T-gNB obtained in S402 (the first type of downlink data may be equivalent to the above-mentioned Figure 3 The first downlink data in the scheme). The first type of downlink data refers to the data packet obtained by the S-gNB using the key of the source cell for encryption and integrity protection. For example, the PDCP protocol data unit (PDU) completed by the key processing of the source cell.

[0195] In this embodiment, if the first type of downlink data can be transmitted through the bearer (or channel logic) identified as 1, then in the above S405, in the step of establishing a connection between UE1 and the target cell, the bearer (or logical channel) corresponding to identifier 1 can be established.

[0196] In S406A, the S-gNB sends the first type of downlink data to the T-gNB through the bearer (or logical channel) corresponding to identifier 1. The T-gNB can identify (determine) that it is the first type of data based on identifier 1 corresponding to the bearer (or logical channel) receiving the first type of downlink data, and then choose to send it to UE1.

[0197] In some other embodiments, the first type of downlink data sent by the S-gNB carries identification information 1, and the identification information 1 is used to identify (or characterize) the first type of data.

[0198] Exemplarily, the S-gNB adds an identifier 1 to the header of the downlink data packet sent to the T-gNB, for example, adds the identifier 1 to the PDCP header, the RLC header, or the MAC header, and the identifier 1 is used to indicate the first type of data. Therefore, after receiving the downlink data packet, the T-gNB can read the identifier 1 therefrom, thereby determining that the downlink data packet is the first type of data, and then the T-gNB sends the downlink data to UE1.

[0199] S406B: T-gNB sends the first type of downlink data to UE1.

[0200] Correspondingly, UE1 receives the first type of downlink data from the S-gNB from the T-gNB; UE1 can identify (judge) that it is the first type of data by receiving the identifier 1 corresponding to the bearer (or logical channel) of the first type of downlink data, or by the identifier information 1 carried in the first type of downlink data, and then, UE1 will choose to use the key of the source cell to decrypt and perform integrity verification on the first type of downlink data.

[0201] S407A: UE1 sends the first type of uplink data to T-gNB.

[0202] Exemplarily, UE1 uses the air interface communication link of the target cell to send the first type of uplink data to T-gNB (the first type of uplink data may be equivalent to the above Figure 3 The first type of uplink data in the solution) The first type of uplink data refers to a data packet obtained by UE1 using the key of the source cell for encryption and integrity protection, such as PDCP PDU.

[0203] Similar to the above S406A, in this embodiment, the first type of data can be transmitted through the bearer (or channel logic) identified as 1. In S407A, UE1 sends the first type of uplink data to T-gNB through the bearer (or logical channel) corresponding to identifier 1. The T-gNB can identify (determine) that it is the first type of data based on the identifier 1 corresponding to the bearer (or logical channel) receiving the first type of uplink data, and then choose to send it to S-gNB.

[0204] In some other embodiments, the first type of uplink data sent by UE1 carries identification information 1, and the identification information 1 is used to identify (or characterize) the first type of data.

[0205] Exemplarily, UE1 adds an identifier 1 to the header of the uplink data packet sent to T-gNB, for example, adds identifier 1 to the PDCP header, RLC header, or MAC header, and the identifier 1 is used to indicate the first type of data. Therefore, after the T-gNB receives the uplink data packet, it can read the identifier 1 therefrom, so that it can be determined that the uplink data packet is the first type of data. Then the T-gNB sends the uplink data to the S-gNB.

[0206] S407B: T-gNB sends the first type of uplink data to S-gNB.

[0207] The T-gNB can send the first type of uplink data to the S-gNB according to the address information of the uplink user plane tunnel of the S-gNB obtained in S401. Furthermore, the S-gNB can use the key of the source cell to decrypt and perform integrity check on the first type of uplink data. After the S-gNB completes the above processing of the first type of uplink data, it can further send the data to the UPF.

[0208] Optionally, UE1 can send the RLC status report to the S-gNB through steps S407A and S407B (equivalent to the first type of uplink data being the RLC status report), so that the S-gNB can know (perceive) which data has been successfully received by UE1 and which data has not been successfully received by UE1 in the following step S411B.

[0209] The above S406A-S406B is the S-gNB sending the first type of downlink data to UE1 through T-gNB. The above S407A-S407B is the UE1 sending the first type of uplink data to S-gNB through T-gNB. In the above S405, after completing the step of connecting UE1 to the target cell, S406A-S406B and / or S407A-S407B (equivalent to continuing the communication between UE1 and S-gNB) can be executed without waiting until all processing steps in S405 are completed, thereby reducing the duration of communication interruption caused by UE1 executing the processing steps. And there is no limit on the time of executing the above S406A-S406B (i.e., the transmission step of the first type of downlink data) and S407A-S407B (i.e., the transmission step of the first type of downlink data).

[0210] S408A: UE1 sends the second type of uplink data to T-gNB.

[0211] After the above S405 is completed (that is, after UE1 executes the processing flow), UE1 has successfully deduced the secret key of the target cell. At this time, UE1 can use the secret key of the target cell to encrypt and integrity protect the uplink data to be sent, and obtain the second type of uplink data (the second type of uplink data can be equivalent to the above Figure 3 The second type of uplink data in the scheme is sent to the T-gNB.

[0212] Correspondingly, after the T-gNB receives the second type of uplink data, it can use the key of the target cell to decrypt and perform integrity verification on the second type of uplink data to obtain the uplink data (i.e., the original data).

[0213] In this embodiment, if the second type of uplink data is transmitted via a bearer (or channel logic) identified as 2, then in the above S405, the step of establishing a connection between UE1 and the target cell may include establishing a bearer (or logical channel) corresponding to identifier 2.

[0214] In S408A, UE1 sends the second type of uplink data to T-gNB through the bearer (or logical channel) corresponding to identifier 2, and T-gNB can identify (determine) that it is the second type of data according to the identifier 2 corresponding to the bearer (or logical channel) receiving the second type of uplink data. Then in the following S408, T-gNB selects to send the second type of uplink data to UPF in the core network after decrypting and integrity checking the second type of uplink data.

[0215] In some other embodiments, the second type of uplink data sent by UE1 carries identification information 2, and the identification information 2 is used to identify (or indicate) the second type of data.

[0216] Exemplarily, UE1 adds an identifier 2 to the header of the uplink data packet sent to T-gNB, for example, adds identifier 2 to the PDCP header, RLC header, or MAC header, and the identifier 2 is used to indicate the second type of data. Therefore, after the T-gNB receives the uplink data packet from UE1, it can read the identifier 2 therefrom, so that it can be determined that the uplink data packet is the second type of data. Then, in the following S408B, T-gNB sends the uplink data to the UPF in the core network.

[0217] Optionally, UE1 can send an RRC reconfiguration completion message to T-gNB through step S408A (that is, the RRC reconfiguration completion message is equivalent to the second type of uplink data mentioned above), which is used to indicate that the configuration information of the target cell has been successfully applied, including that UE1 has validated the key of the target cell.

[0218] S408B: T-gNB sends uplink data to UPF.

[0219] The uplink data is the second type of uplink data from UE1 that has been decrypted and integrity checked.

[0220] In the above S408A-S408B, UE1 uses the key of the target cell to perform uplink transmission of the second type of data with T-gNB, and then T-gNB sends the data from UE1 to the UPF in the core network.

[0221] S409A: T-gNB sends path switching request information to AMF.

[0222] The path switching request information is used to request the core network device to switch the path of downlink data from the path corresponding to the S-gNB to the path corresponding to the T-gNB; wherein the path corresponding to the S-gNB (which may be equivalent to the above Figure 3 The first path in the scheme) refers to the transmission path between S-gNB and UPF, and the path corresponding to T-gNB (which can be equivalent to the above Figure 3 The second path in the scheme refers to the transmission path between T-gNB and UPF. For example, the path switching request information is used to request that the termination point address of the downlink user plane tunnel be switched from the address of S-gNB to the address of T-gNB.

[0223] In the embodiment of the present application, step S409A can be executed after the above step S408A, that is, after receiving the second type of uplink data sent by UE1, T-gNB can know that UE1 has completed the processing flow in step S405, then UE1 can send path switching request information to AMF in the core network. Since S408B and S409A are both executed after S408A, the execution order of S408B and S409A is not specifically limited.

[0224] In one implementation, step S409A may also be performed after S406A, that is, after the T-gNB receives the first type of downlink data sent by the S-gNB, the T-gNB sends a path switching request information to the AMF in the core network.

[0225] In another implementation, step S409A may also be performed after S407A, that is, after T-gNB receives the first type of uplink data sent by UE1, T-gNB sends path switching request information to AMF in the core network.

[0226] S409B: Perform path switching between AMF and UPF.

[0227] The path switching process (procedure) of UE1 executed between AMF and UPF can be specifically implemented with reference to the prior art and will not be described in detail here. It should be understood that the path switching process executed between AMF and UPF may also involve the participation of SMF.

[0228] After S409B, the core network equipment completes the switching of the downlink data path, that is, switching from the path corresponding to S-gNB to the path corresponding to T-gNB (that is, switching from the transmission path between S-gNB and UPF to the transmission path between T-gNB and UPF).

[0229] S409C: AMF sends path switching response information to T-gNB.

[0230] Correspondingly, the T-gNB receives the path switching response information, which is used to indicate that the above-mentioned path switching has been completed.

[0231] S410A: UPF sends downlink data to T-gNB.

[0232] In step S410A, after T-gNB receives the downlink data (unencrypted original data) from UPF, it can use the key of the target cell to encrypt and integrity protect the downlink data to obtain the second type of downlink data.

[0233] S410B: T-gNB sends the second type of downlink data to UE1.

[0234] Correspondingly, UE1 can receive the second type of downlink data sent by the T-gNB through the target cell (the second type of downlink data can be equivalent to the above Figure 3 The second downlink data in the scheme). UE1 can identify (determine) that it is the second type of data by receiving the identifier 2 corresponding to the bearer (or logical channel) of the second type of downlink data, or by the identifier information 2 carried in the second type of downlink data, and then UE1 will choose to use the secret key of the target cell to decrypt and perform integrity verification on the second type of downlink data.

[0235] Since UE1 has deduced the secret key of the target cell and completed the path switching, in step S410B, UE1 can also use the secret key of the target cell to decrypt and perform integrity check on the second type of downlink data to obtain the original data.

[0236] S411A: T-gNB sends indication information 1 to S-gNB.

[0237] Correspondingly, the S-gNB receives the indication information 1 from the T-gNB.

[0238] The indication information 1 is used to instruct the S-gNB to stop generating the first type of downlink data, and to stop sending the first type of downlink data.

[0239] In this embodiment, since the first type of uplink data / downlink data is transmitted using the bearer (or logical channel) corresponding to identifier 1, the S-gNB will also release the bearer (or logical channel) corresponding to identifier 1 according to the indication information 1.

[0240] S411B: S-gNB sends data transmission status information and data forwarding to T-gNB.

[0241] The data transmission status information is used to inform the sequence number (or ID) of the data packet that has been successfully sent and / or unsuccessfully sent. For example, a sequence number status transmission message is sent to indicate the receiving status of the uplink data sequence number and the sending status of the downlink data sequence number.

[0242] Optionally, the S-gNB sends the downlink data packets that were not successfully sent (i.e., the original data packets that were not encrypted and integrity protected), such as the PDCP service data unit (SDU), to the target gNB. In this way, the target gNB can continue to send the data packets that were not successfully sent from the S-gNB to UE1. For uplink data packets, the S-gNB can submit the sorted data packets to the UPF (e.g., data packet sequence numbers 1, 2, 3 that increase in sequence by 1), and send the unsorted data packets to the T-gNB (e.g., data packet sequence numbers 6, 7, 9 with sequence number holes), which will be submitted to the UPF by the T-gNB after the sorting is completed (i.e., after the sequence number holes are filled).

[0243] S412A: T-gNB sends indication information 2 to UE1.

[0244] Correspondingly, UE1 receives the indication information 2 from T-gNB.

[0245] The indication information 2 may be used to instruct the UE1 to stop using the source cell key for data processing and to stop processing operations related to the source cell key, and may also instruct the UE1 to delete the source cell key.

[0246] In this embodiment, the first type of uplink data / downlink data is transmitted using the bearer (or logical channel) corresponding to the identifier 1. Therefore, the UE1 can also release the bearer (or logical channel) corresponding to the identifier 1 according to the indication information 2.

[0247] In addition, after receiving the indication information 2, UE1 no longer carries the relevant identifier of the first type of data in the data packet (the relevant identifier of the first type of data is equivalent to the above Figure 3The first target identifier in the scheme), such as the identifier 1 of the bearer 1, the identifier 1 of the logical channel 1, and the identifier 1, no longer carries the relevant identifier of the second type of data with the data packet (the relevant identifier of the second type of data is equivalent to the above Figure 3 The second target identifier in the scheme), for example, the identifier 2 of bearer 2, the identifier 2 of logical channel 2, and the identifier 2 mentioned above.

[0248] In the embodiment of the present application, the above S411A and S412A may be executed synchronously or asynchronously, and the order of execution is not specifically limited.

[0249] S412B: UE1 sends feedback information to T-gNB.

[0250] This feedback information is used to inform T-gNB that UE1 has successfully received indication information 2.

[0251] After S411B and / or S412B (i.e., when receiving status information and data fed back by the S-gNB, or when receiving feedback information from UE1, or when receiving status information and data of data transmission fed back by the S-gNB and feedback information from UE1), T-gNB may no longer carry relevant identifiers of the first type of data (for example, the above-mentioned identifier 1 of bearer 1, identifier 1 of logical channel 1), and no longer carry relevant identifiers of the second type of data (for example, the above-mentioned identifier 2 of bearer 2, identifier 2 of logical channel 2, identifier 2) with the data packet.

[0252] In this embodiment one, taking UE1 as an example, for the scenario where UE1 switches base stations (or UE switches cells), in the switching process of UE1 (including UE1 executing the processing flow and the path switching process between the target base station and the core network), UE1 can maintain data transmission with the source base station through the air interface link of the target base station, thereby effectively reducing the duration of communication interruption due to UE1 executing the switching.

[0253] Embodiment 2:

[0254] Based on the above Figure 2 In the CU-DU separation architecture shown, a base station can be logically divided into a centralized unit CU and one or more distributed units DU. Each DU is connected to the CU through the F1 logical interface. The operations related to the radio link control RLC layer, the medium access control MAC layer and the physical layer PHY layer are processed by the DU, and the operations related to the service data adaptation protocol SDAP layer, the radio resource control RRC layer and the packet data convergence protocol PDCP layer are processed by the CU.

[0255] In this second embodiment, specifically, the source base station (S-gNB) is divided into S-gNB-CU (hereinafter referred to as source CU) and S-gNB-DU (hereinafter referred to as source DU), and the target base station (T-gNB) is divided into T-gNB-CU (hereinafter referred to as target CU) and T-gNB-DU (hereinafter referred to as target DU). The specific implementation method of the steps (S501 to S512B) described in this second embodiment can refer to the specific implementation method of the steps (S401 to S412B) described in the above-mentioned first embodiment one by one, and will not be described in detail here. The steps shown in this second embodiment can be a detailed description of the information interaction in the scheme described in the first embodiment. See Figure 5 As shown, the process of the second embodiment is as follows:

[0256] Specifically, the specific path of the downlink transmission in this embodiment can be found in Fig. 6A The specific path of the uplink transmission in this embodiment can be found in Figure 6B , where the path corresponding to line 1 represents the transmission path before UE1 switches, line 2 represents the transmission path during UE1 switching, and line 3 represents the transmission path after UE1 switches.

[0257] S501: The source CU (S-gNB-CU) sends a switching request message to the target CU (T-gNB-CU).

[0258] It should be understood that after receiving the handover request message, the target CU sends the relevant information in the handover request message to the target DU through the F1 interface, for example, sends the first configuration information of the source cell to the target DU, and requests the target DU to use the same configuration information as the first configuration information. The interaction process between the target CU and the target DU is omitted in the figure.

[0259] S502: The target CU (T-gNB-CU) sends a handover request response message to the source CU (S-gNB-CU).

[0260] S503: The source DU (S-gNB-DU) sends a first switching command to UE1, where the first switching command is used to request UE1 to switch from the source cell to the target cell.

[0261] The first handover command may be an RRC message, which is sent by the source CU to the source DU, and further sent by the source DU to UE1; the first handover command may also be a MAC CE or downlink control information (DCI) message, which is generated by the source DU itself and sent to UE1. The interaction process between the source CU and the source DU is omitted in the figure.

[0262] S504: UE1 sends a first response message to the source DU (S-gNB-DU).

[0263] Optionally, the source DU further sends a first response message to the source CU. The interaction process between the source CU and the source DU is omitted in the figure.

[0264] S505: UE1 executes a processing flow based on the handover command.

[0265] S506A: The source CU (S-gNB-CU) sends the first type of downlink data to the target DU (T-gNB-DU).

[0266] It should be understood that in a possible network deployment, there is no direct communication connection between the source CU and the target DU, then the first type of downlink data may also be sent via the target CU, that is, the source CU sends it to the target CU, and the target CU further sends it to the target DU.

[0267] S506B: The target DU (T-gNB-DU) sends the first type of downlink data to UE1.

[0268] The specific transmission paths corresponding to the above steps S506A-S506B can be referred to Fig. 6A The path shown by the middle line 2 is used to transmit the first type of downlink data.

[0269] S507A: UE1 sends the first type of uplink data to the target DU (T-gNB-DU).

[0270] S507B: The target DU (T-gNB-DU) sends the first type of uplink data to the source CU (S-gNB-CU).

[0271] It should be understood that in a possible network deployment, there is no direct communication connection between the source CU and the target DU, then the first type of uplink data may also be sent via the target CU, that is, the target DU is sent to the target CU, and the target CU is further sent to the source U.

[0272] The specific transmission paths corresponding to the above steps S507A-S507B can be referred to Figure 6B The first type of uplink data is transmitted along the path shown by the center line 2.

[0273] S508A: UE1 sends the second type of uplink data to the target DU (T-gNB-DU).

[0274] Furthermore, the target DU sends the uplink data to the target CU via the F1 interface. Figure 5 This step is not shown in FIG.

[0275] S508B: The target CU (T-gNB-CU) sends uplink data to UPF.

[0276] In the above step S508A, the specific transmission path for UE1 to send the second type of uplink data to T-gNB can refer to Figure 6B The path shown by line 3.

[0277] S509A: The target CU (T-gNB-CU) sends a path switching request message to the AMF.

[0278] S509B: Path switching is performed between AMF and UPF.

[0279] S509C: AMF sends path switching response information to the target CU (T-gNB-CU).

[0280] S510A: UPF sends downlink data to the target CU (T-gNB-CU).

[0281] Furthermore, the target CU sends the downlink data to the target DU via the F1 interface. Figure 5 This step is not shown in FIG.

[0282] S510B: The target DU (T-gNB-DU) sends the second type of downlink data to UE1.

[0283] In step S510B, the specific transmission path for T-gNB to send the second type of downlink data to UE1 can refer to Fig. 6A The path shown by line 3.

[0284] S511A: The target CU (T-gNB-CU) sends indication information 1 to the source CU (S-gNB-CU).

[0285] S511B: The source CU (S-gNB-CU) sends data transmission status information and data forwarding to the target CU (T-gNB-CU).

[0286] S512A: The target DU (T-gNB-DU) sends indication information 2 to UE1.

[0287] The indication information 2 may be an RRC message, which is sent by the target CU to the target DU, and further sent by the target DU to UE1; the first handover command may also be a MAC CE or DCI message, which is generated by the target DU itself and sent to UE1. The interaction process between the target CU and the target DU is omitted in the figure.

[0288] S512B: UE1 sends feedback information to the target DU (T-gNB-DU).

[0289] Embodiment three:

[0290] The difference between the third embodiment and the first embodiment is that after UE1 accesses the target cell through the air interface link of the target cell, the target base station can obtain the key parameters of the target cell from the AMF in the core network and send the key parameters of the target cell to UE1. Figure 7 As shown, the process of the third embodiment is as follows:

[0291] The specific implementation of steps S701 to S704 may refer to the specific implementation of steps S401 to S404 in the first embodiment, and will not be described in detail here.

[0292] However, unlike the above step S401, the handover request message in step S701 does not include the target cell's key or the target cell's key parameter derived from the source cell. Unlike the above step S402, the handover request response message in step S702 does not include the target cell's key parameter. Unlike the above step S403, the first handover command in step S703 does not include the target cell's key parameter.

[0293] S705: UE1 establishes a connection with the target cell.

[0294] In step S705, one or more of the following steps may be performed:

[0295] (1) UE1 establishes a connection with the target cell;

[0296] (2) Configuration information of the effective target cell;

[0297] If the target cell uses the same configuration information as the source cell (such as the first configuration information), then in this step, UE1 can maintain the configuration information of the source cell. If the target cell does not agree to use the same configuration information as the source cell, then in this step, UE1 can validate the configuration information of the target cell.

[0298] (3) Baseband adjustment for the target cell;

[0299] (4) Adjust the radio frequency unit for the target cell.

[0300] Through this step, UE1 successfully accesses the target cell, and then the following steps S706A-S706B and / or S707A-S707B may be executed.

[0301] S706A: S-gNB sends the first type of downlink data to T-gNB.

[0302] S706B: T-gNB sends the first type of downlink data to UE1.

[0303] The specific implementation of the above steps S706A-S706B can refer to the specific implementation of the above steps S406A-S406B one by one, and will not be described in detail here.

[0304] S707A: UE1 sends the first type of uplink data to T-gNB.

[0305] S707B: T-gNB sends the first type of uplink data to S-gNB.

[0306] The specific implementation methods of the above steps S707A-S707B can refer to the specific implementation methods of the above steps S407A-S407B one by one, and will not be described in detail here.

[0307] In S707A, when the T-gNB receives the first type of uplink data, the following S708A can be executed.

[0308] Optionally, the T-gNB may also execute the following S708A after the above S706A, that is, after receiving the first type of downlink data sent by the S-gNB, the T-gNB sends a path switching request information to the AMF.

[0309] S708A: T-gNB sends path switching request information to AMF.

[0310] S708B: Perform path switching between AMF and UPF.

[0311] S708C: AMF sends path switching response information to T-gNB.

[0312] The specific implementation methods of the above steps S708A-S708C can refer to the specific implementation methods of the above steps S409A-S409C one by one, and will not be described in detail here.

[0313] However, it is different from the above S409C, wherein the path switching request response information in step S708C carries the key parameters of the target cell, specifically, may include key parameter 1 and key parameter 2; wherein key parameter 1 is sent to UE1, and UE1 deduces the key of the target cell; key parameter 2 is used by the network device to which the target cell belongs to deduce the key of the target cell.

[0314] During the process of performing path switching between AMF and UPF (which may include the above steps S708A-S708C), UE1 can refer to the above steps S706A-S706B and / or S707A-S707B, and use the key of the source cell to transmit the first type of data through T-gNB and S-gNB, which will not be described in detail here.

[0315] S709: T-gNB sends the key parameters of the target cell to UE1.

[0316] After receiving the key parameter of the target cell (eg, key parameter 1 in S708C), UE1 may perform the key derivation process of the target cell in S710 described below.

[0317] S710: UE1 executes a processing flow based on the handover command.

[0318] Specifically, in step S710, UE1 performs the derivation of the secret key of the target cell and uses the secret key of the target cell to encrypt and protect the data integrity, which can be implemented with reference to (5) and (6) in S405 above. Steps (5) and (6) are equivalent to the process of UE1 re-establishing PDCP. However, unlike S405 above, step S710 does not include the steps related to UE1 establishing a connection with the target cell (such as steps (1) to (4) described in S405). The steps related to UE1 establishing a connection with the target cell are completed in S705 above.

[0319] After S710, UE1 can deduce the secret key of the target cell, and then use the secret key of the target cell to perform the second type of data transmission with T-gNB.

[0320] S711A: UE1 sends the second type of uplink data to T-gNB.

[0321] S711B: T-gNB sends uplink data to UPF.

[0322] The specific implementation methods of the above steps S711A-S711B can refer to the specific implementation methods of the above steps S408A-S408B one by one, and will not be described in detail here.

[0323] S712A: UPF sends downlink data to T-gNB.

[0324] S712B: T-gNB sends the second type of downlink data to UE1.

[0325] The specific implementation methods of the above steps S712A-S712B can refer to the specific implementation methods of the above steps S410A-S410B one by one, and will not be described in detail here.

[0326] S713A: T-gNB sends indication information 1 to S-gNB.

[0327] S713B: The S-gNB sends data transmission status information and data forwarding to the T-gNB.

[0328] The specific implementation methods of the above steps S713A-S713B can refer to the specific implementation methods of the above steps S411A-S411B one by one, and will not be described in detail here.

[0329] S714A: T-gNB sends indication information 2 to UE1.

[0330] S714B: UE1 sends feedback information to T-gNB.

[0331] The specific implementation of the above steps S714A-S714B can refer to the specific implementation of the above steps S412A-S412B, which will not be described in detail here.

[0332] Since in the scheme described in the above embodiment 1, the target cell key parameters obtained by the target base station are provided by the source base station, and the source base station carries the target cell key parameters in the first handover command and sends it to UE1, the source base station can obtain the target cell key parameters, and then the target cell key. In this embodiment 3, the target base station can directly obtain the new target cell key parameters from the AMF, thereby effectively avoiding security risks.

[0333] It should be noted that the solution described in the third embodiment can also be applied to Figure 2 The CU-DU separation architecture shown, the specific interaction method can be implemented by referring to the interaction method described in the above embodiment 2, and will not be described in detail here.

[0334] In the embodiments provided by the present application, the methods provided by the embodiments of the present application are introduced from the perspective of interaction between various devices. In order to implement the functions in the methods provided by the embodiments of the present application, the terminal device or the first access network device or the second access network device may include a hardware structure and / or a software module to implement the above functions in the form of a hardware structure, a software module, or a hardware structure plus a software module. Whether one of the above functions is executed in the form of a hardware structure, a software module, or a hardware structure plus a software module depends on the specific application and design constraints of the technical solution.

[0335] The division of modules in the embodiments of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation. In addition, each functional module in each embodiment of the present application may be integrated into a processor, or may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated modules may be implemented in the form of hardware or in the form of software functional modules.

[0336] Same as above idea, Figure 8As shown, the embodiment of the present application also provides a communication device 800 for implementing the functions of the terminal device or the first access network device or the second access network device in the above method. For example, the communication device 800 can be a software module or a chip system. In the embodiment of the present application, the chip system can be composed of a chip, or it can include a chip and other discrete devices. The communication device 800 may include: a communication unit 801 and a processing unit 802.

[0337] In the embodiment of the present application, the communication unit 801 may also be referred to as a transceiver unit, and may include a sending unit and / or a receiving unit, which are respectively used to execute the steps of sending and receiving by the terminal device or the first access network device or the second access network device in the above method embodiment. The processing unit 802 may be used to read instructions and / or data in the storage module so that the communication device 800 implements the above method embodiment.

[0338] Optionally, the communication device 800 may further include a storage unit 803, which is equivalent to a storage module and can be used to store instructions and / or data.

[0339] The following, combined Figures 8 to 9 The communication device provided in the embodiment of the present application is described in detail. It should be understood that the description of the device embodiment corresponds to the description of the method embodiment, so the contents not described in detail can be referred to above. Figure 3-Figure 4 - Figure 7 For the sake of brevity, the method embodiment will not be described in detail here.

[0340] The communication unit 801 may also be referred to as a transceiver, a transceiver, a transceiver device, etc. The processing unit may also be referred to as a processor, a processing board, a processing module, a processing device, etc. Optionally, the device used to implement the receiving function in the communication unit 801 may be regarded as a receiving unit, and the device used to implement the sending function in the communication unit 801 may be regarded as a sending unit, that is, the communication unit 801 includes a receiving unit and a sending unit. The communication unit may also be sometimes referred to as a transceiver, a transceiver, or a transceiver circuit, etc. The receiving unit may also be sometimes referred to as a receiver, a receiver, or a receiving circuit, etc. The sending unit may also be sometimes referred to as a transmitter, a transmitter, or a transmitting circuit, etc.

[0341] When the communication device 800 executes the above embodiment Figure 3 In the process shown, when the terminal device:

[0342] The communication unit 801 is used to receive a first switching message from a first access network device, where the first switching message is used to instruct the terminal device to switch from a current first cell to a second cell, where the second cell is a cell under the jurisdiction of the second access network device;

[0343] The processing unit 802 is configured to perform first data transmission with the second access network device using the secret key of the first cell based on the first switching message.

[0344] When the communication device 800 executes the above embodiment Figure 3 In the process shown, when the first access network device:

[0345] The communication unit 801 is used to send a first switching message to the terminal device, where the first switching message is used to instruct the terminal device to switch from a first cell currently located to a second cell, where the second cell is a cell under the jurisdiction of a second access network device;

[0346] The communication unit 801 is further configured to perform first data transmission with the second access network device using the secret key of the first cell.

[0347] The processing unit 802 is used to process data and / or information.

[0348] When the communication device 800 executes the above embodiment Figure 3 In the process shown, when the second access network device:

[0349] The communication unit 801 is used to receive downlink first data from the first access network device and send the downlink first data to the terminal device; and / or receive uplink first data from the terminal device and send the uplink first data to the first access network device; wherein the first data is data obtained by encryption and integrity protection using the key of the first cell.

[0350] The processing unit 802 is used to process data and / or information.

[0351] The above is just an example. The processing unit 802 and the communication unit 801 can also perform other functions. For more detailed description, please refer to Figure 3 The relevant description in the method embodiment shown is not repeated here.

[0352] like Fig. 9 The figure shows a communication device 900 provided in an embodiment of the present application. Fig. 9 The communication device shown can be Figure 8 The communication device 900 can be applied to the flowchart shown above to perform the functions of the terminal device or the first access network device or the second access network device in the above method embodiment. For the convenience of explanation, Fig. 9 Only the main components of the communication device are shown.

[0353] like Fig. 9As shown, the communication device 900 includes a communication interface 901 and a processor 902. The communication interface 901 and the processor 902 are coupled to each other. It can be understood that the communication interface 901 can be a transceiver or an input-output interface, or an interface circuit such as a transceiver circuit. Optionally, the communication device 900 can also include a memory 903 for storing instructions executed by the processor 902 or storing input data required by the processor 902 to run the instructions or storing data generated after the processor 902 runs the instructions.

[0354] When the communication device 900 is used to implement Figure 3-Figure 4 - Figure 7 In the method shown, the communication interface 901 is used to implement the functions of the above-mentioned communication unit 801, and the processor 902 is used to implement the functions of the above-mentioned processing unit 802.

[0355] The specific connection medium between the communication interface 901, the processor 902 and the memory 903 is not limited in the embodiment of the present application. Fig. 9 In the embodiment, the memory 903, the processor 902 and the communication interface 901 are connected via a communication bus 904. Fig. 9 The communication bus 904 can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Fig. 9 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0356] When the communication device is a chip, Fig.10 A simplified schematic diagram of a chip device structure is shown, wherein the chip 1000 includes an interface circuit 1001 and one or more processors 1002. Optionally, the chip 1000 may also include a bus.

[0357] Processor 1002 may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above communication method can be completed by an integrated logic circuit of hardware in processor 1002 or an instruction in software form. The above processor 1002 can be a general-purpose processor, a digital communicator (DSP), an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component. The disclosed methods and steps in the embodiments of the present application can be implemented or executed. The general-purpose processor can be a microprocessor or the processor can also be any conventional processor, etc.

[0358] The interface circuit 1001 can be used to send or receive data, instructions or information. The processor 1002 can use the data, instructions or other information received by the interface circuit 1001 to process, and can send the processing completion information through the interface circuit 1001.

[0359] Optionally, the chip further includes a memory 1003, which may include a read-only memory and a random access memory, and provides operation instructions and data to the processor. A portion of the memory 1003 may also include a non-volatile random access memory (NVRAM).

[0360] Optionally, the memory stores executable software modules or data structures, and the processor can perform corresponding operations by calling operation instructions stored in the memory (the operation instructions can be stored in the operating system).

[0361] Optionally, the chip can be used in the terminal device or the first access network device or the second access network device involved in the embodiment of the present application. Optionally, the interface circuit 1001 can be used to output the execution result of the processor 1002. The communication method provided by one or more embodiments of the present application can refer to the aforementioned embodiments, which will not be repeated here.

[0362] It should be noted that the functions corresponding to the interface circuit 1001 and the processor 1002 can be implemented through hardware design, software design, or a combination of hardware and software, and there is no limitation here.

[0363] An embodiment of the present application also provides a computer-readable storage medium on which computer instructions for implementing the method executed by the terminal device or the first access network device or the second access network device in the above method embodiment are stored.

[0364] For example, when the computer program is executed by a computer, the computer can implement the method performed by the terminal device or the first access network device or the second access network device in the above method embodiment.

[0365] An embodiment of the present application also provides a computer program product comprising instructions, which, when executed by a computer, enables the computer to implement the method performed by the terminal device or the first access network device or the second access network device in the above method embodiment.

[0366] The embodiment of the present application also provides a chip, including a processor, which is used to call the computer program or computer instruction stored in the memory so that the processor executes the above Figure 3-Figure 4 - Figure 7 The communication method of the embodiment shown.

[0367] In a possible implementation, the chip input corresponds to the above Figure 3-Figure 4 - Figure 7 In the receiving operation of the embodiment shown, the output of the chip corresponds to the above Figure 3-Figure 4 - Figure 7 The sending operation in the embodiment shown.

[0368] Optionally, the processor is coupled to the memory via an interface.

[0369] Optionally, the chip also includes a memory in which computer programs or computer instructions are stored.

[0370] The processor mentioned in any of the above may be a general-purpose central processing unit, a microprocessor, an application-specific integrated circuit (ASIC), or one or more processors for controlling the above Figure 3-Figure 4 - Figure 7 An integrated circuit for executing a program of a communication method of the embodiment shown. The memory mentioned in any of the above places can be a read-only memory (ROM) or other types of static storage devices that can store static information and instructions, a random access memory (RAM), etc.

[0371] It should be noted that, for the sake of convenience and brevity of description, the explanation of the relevant contents and beneficial effects in any of the communication devices provided above may refer to the corresponding communication method embodiments provided above, and will not be repeated here.

[0372] In the present application, the communication devices may also include a hardware layer, an operating system layer running on the hardware layer, and an application layer running on the operating system layer. Among them, the hardware layer may include hardware such as a central processing unit (CPU), a memory management unit (MMU), and a memory (also called main memory). The operating system of the operating system layer may be any one or more computer operating systems that implement business processing through processes, such as Linux operating system, Unix operating system, Android operating system, iOS operating system, or Windows operating system. The application layer may include applications such as browsers, address books, word processing software, and instant messaging software.

[0373] The division of modules in the embodiments of the present application is schematic and is only a logical function division. There may be other division methods in actual implementation. In addition, each functional module in each embodiment of the present application may be integrated into a processor, or may exist physically separately, or two or more modules may be integrated into one module. The above-mentioned integrated modules may be implemented in the form of hardware or in the form of software functional modules.

[0374] Through the description of the above implementation mode, it can be clearly understood by those skilled in the art that the embodiments of the present application can be implemented by hardware, firmware, or a combination thereof. When software is used for implementation, the above functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein the communication media include any medium that facilitates the transmission of a computer program from one place to another. The storage medium can be any available medium that a computer can access. Taking this as an example but not limited to: a computer-readable medium can include RAM, ROM, electrically erasable programmable read only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store a desired program code in the form of an instruction or data structure and can be accessed by a computer. In addition. Any connection can be appropriately a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, wireless, and microwave are included in the fixation of the medium. As used in the embodiments of the present application, disk and disc include compact disc (CD), laser disc, optical disc, digital video disc (DVD), floppy disk, and Blu-ray disc, where disks usually copy data magnetically and discs use lasers to copy data optically. The above combinations should also be included in the scope of protection of computer-readable media.

[0375] In short, the above description is only an embodiment of the present application and is not intended to limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. made according to the disclosure of the present application shall be included in the protection scope of the present application.

Claims

1. A communication method, characterized in that: The method is applied to a terminal device, comprising: Receiving a first handover message from a first access network device, where the first handover message is used to instruct the terminal device to switch from a first cell currently located to a second cell, where the second cell is a cell under the jurisdiction of the second access network device; Based on the first switching message, a secret key of the first cell is used to perform first data transmission with the second access network device.

2. The method according to claim 1, characterized in that The first handover message includes cell configuration indication information, where the cell configuration indication information is used to indicate that the second cell uses the same configuration information as the first cell.

3. The method according to claim 1 or 2, characterized in that: The using the secret key of the first cell to perform first data transmission with the second access network device includes: When a communication connection is established with the second cell and the secret key of the second cell is not derived, the secret key of the first cell is used to perform first data transmission with the second access network device.

4. The method according to claim 3, characterized in that The using the secret key of the first cell to perform first data transmission with the second access network device includes: Using the secret key of the first cell to encrypt and integrity protect the uplink data to obtain uplink first data; sending the uplink first data to the second access network device; and / or Receive downlink first data from the second access network device, and use the secret key of the first cell to decrypt and perform integrity verification on the downlink first data.

5. The method according to claim 3, characterized in that: After establishing a communication connection with the second cell, the method further includes: receiving configuration information of a key of the second cell from the second access network device.

6. The method according to any one of claims 3 to 5, characterized in that The method further comprises: The first data is identified by a first target identifier, where the first target identifier is any one of the following: An identifier of a first bearer, an identifier of a first logical channel, and a first identifier carried in the first data; wherein the first bearer or the first logical channel is used to transmit the first data.

7. The method according to any one of claims 1 to 6, characterized in that After deducing the secret key of the second cell, the method further includes: Using the secret key of the second cell to perform encryption and integrity protection processing on the uplink data to obtain uplink second data; sending the uplink second data to the second access network device; and / or Receive downlink second data from the second access network device, and use the secret key of the second cell to decrypt and perform integrity verification on the downlink second data.

8. The method according to claim 7, characterized in that The method further comprises: The second data is identified by a second target identifier, where the second target identifier is any one of the following: An identifier of a second bearer, an identifier of a second logical channel, and a second identifier carried in the second data; wherein the second bearer or the second logical channel is used to transmit the second data.

9. The method according to any one of claims 1 to 8, characterized in that The method further comprises: Receive first indication information from the second access network device, where the first indication information is used to instruct the terminal device to perform one or more of the following: Stop using the key of the first cell to process data, delete the key of the first cell, stop processing associated with the key of the first cell, release the first bearer or first logical channel of the first data, and stop carrying the second identifier in the second data.

10. A communication method, characterized in that: The communication method is applied to a first access network device, comprising: Sending a first switching message to a terminal device, where the first switching message is used to instruct the terminal device to switch from a first cell currently located to a second cell, where the second cell is a cell under the jurisdiction of a second access network device; Use the secret key of the first cell to perform first data transmission with the second access network device.

11. The method according to claim 10, characterized in that Before sending the first switching message to the terminal device, the method further includes: sending first switching request information to the second access network device, wherein the first switching request information includes address information of a user plane tunnel of the first access network device; A first switching response message is received from the second access network device, where the first switching response message includes address information of a user plane tunnel of the second access network device.

12. The method according to claim 11, characterized in that The first switching request information also includes third indication information, and the third indication information is used to request the second cell to use the configuration information of the first cell; the first switching response information is used to indicate that the second cell confirms the use of the configuration information of the first cell; wherein the configuration information of the first cell includes the uplink physical layer channel configuration information of the first cell and the downlink physical layer channel configuration information of the first cell.

13. The method according to any one of claims 10 to 12, characterized in that Before using the secret key of the first cell to transmit the first data with the second access network device, the method further includes: receiving a first response message from the terminal device, where the first response message is used to notify the terminal device to confirm switching from the first cell to the second cell; The using the secret key of the first cell to perform first data transmission with the second access network device includes: Using the secret key of the first cell to encrypt and integrity protect the downlink data, to obtain downlink first data; sending the downlink first data to the second access network device according to the address information of the user plane tunnel of the second access network device; and / or Receive uplink first data from the second access network device, use the secret key of the first cell to decrypt and perform integrity verification on the uplink first data, and obtain uplink data.

14. The method according to any one of claims 10 to 13, characterized in that The method further comprises: receiving second indication information from the second access network device, where the second indication information is used to instruct the first cell or the first access network device to stop generating or sending the first data, and to release a first bearer or a first logical channel of the first data; Sending first status information to the second access network device, where the first status information is used to indicate identification information of the first data that has been successfully sent and / or unsuccessfully sent.

15. The method according to claim 14, characterized in that The method further comprises: Sending third data to the second access network device, where the third data is the unsuccessfully sent data that has not been encrypted and integrity protected.

16. The method according to any one of claims 10 to 15, characterized in that The method further comprises: The first data is identified by a first target identifier, where the first target identifier is any one of the following: An identifier of a first bearer, an identifier of a first logical channel, and a first identifier carried in the first data; wherein the first bearer or the first logical channel is used to transmit the first data.

17. A communication method, characterized in that: The communication method is applied to a second access network device, comprising: Receive first downlink data from the first access network device, and send the first downlink data to the terminal device; and / or receiving first uplink data from the terminal device, and sending the first uplink data to the first access network device; The first data is data obtained by performing encryption and integrity protection processing using the secret key of the first cell.

18. The method according to claim 17, characterized in that The method further comprises: receiving first switching request information from the first access network device, where the first switching request information includes address information of a user plane tunnel of the first access network device; Sending first switching response information to the first access network device, where the first switching response information includes address information of the user plane tunnel of the second access network device.

19. The method according to claim 18, characterized in that The first switching request information also includes third indication information, and the third indication information is used to request the second cell to use the configuration information of the first cell; the first switching response information is used to indicate that the second cell confirms the use of the configuration information of the first cell; wherein the configuration information of the first cell includes the uplink physical layer channel configuration information of the first cell and the downlink physical layer channel configuration information of the first cell.

20. The method according to claim 18, characterized in that The sending the uplink first data to the first access network device includes: The uplink first data is sent to the first access network device according to the address information of the user plane tunnel of the first access network device.

21. The method according to any one of claims 17 to 20, characterized in that The method further comprises: receiving uplink second data from the terminal device; decrypting and integrity checking the uplink second data using the secret key of the second cell to obtain uplink data; sending the uplink data to a user plane function network element in a core network device; and / or Receive downlink data from the user plane functional network element in the core network device and / or the first access network device; use the secret key of the second cell to encrypt and integrity protect the downlink data to obtain downlink second data; and send the downlink second data to the terminal device.

22. The method according to claim 17 or 21, characterized in that The method further comprises: After the first event, a path switching request message is sent to an access and mobility management function network element in a core network device; the path switching request message is used to request that a data transmission path be switched from a first path corresponding to a user plane function network element and the first access network device to a second path corresponding to a user plane function network element and the second access network device; the first event is any one of the following: The first downlink data is received from the first access network device, the first uplink data is received from the terminal device, and the second uplink data is received from the terminal device.

23. The method according to claim 22, characterized in that The method further comprises: receiving a path switch response message from the access and mobility management function network element, and acquiring configuration information of a secret key of the second cell from the path switch response message; The path switching response information is used to indicate that the data transmission path has been switched from the first path to the second path.

24. The method according to claim 23, characterized in that The method further comprises: Sending first indication information to the terminal device, and sending second indication information to the first access network device; The first indication information is used to instruct the terminal device to perform one or more of the following: Stop using the key of the first cell to process data, delete the key of the first cell, stop processing associated with the key of the first cell, release the first bearer or first logical channel of the first data, and stop carrying the second identifier in the second data; The second indication information is used to instruct the first cell or the first access network device to stop generating or sending the first data and release the first bearer or first logical channel of the first data.

25. The method according to claim 23, characterized in that The method further comprises: First status information is received from the first access network device, where the first status information is used to indicate identification information of the first data that has been successfully sent and / or unsuccessfully sent.

26. The method according to claim 25, characterized in that The method further comprises: The third data is received from the first access network device, where the third data is the unsuccessfully sent data that is not encrypted and integrity protected.

27. The method according to any one of claims 17 to 26, characterized in that The method further comprises: The first data is identified by a first target identifier, where the first target identifier is any one of the following: an identifier of a first bearer, an identifier of a first logical channel, and a first identifier carried in the first data; the first bearer or the first logical channel is used to transmit the first data; The second data is identified by a second target identifier, where the second target identifier is any one of the following: An identifier of a second bearer, an identifier of a second logical channel, and a first identifier carried in the second data; the second bearer or the second logical channel is used to transmit the second data.

28. A communication device, characterized in that: The method comprises a module or a unit for executing the method according to any one of claims 1 to 9, or a module or a unit for executing the method according to any one of claims 10 to 16, or a module or a unit for executing the method according to any one of claims 17 to 27.

29. A communication device, characterized in that: The invention comprises a processor and an interface circuit, wherein the interface circuit is used to receive signals from other communication devices outside the communication device and transmit them to the processor or send signals from the processor to other communication devices outside the communication device, and the processor is used to implement the method as described in any one of claims 1 to 9, or implement the method as described in any one of claims 10 to 16, or implement the method as described in any one of claims 17 to 27 through a logic circuit or executing code instructions.

30. A communication system, characterized in that: include: A terminal device and a first access network device and a second access network device; the terminal device is used to implement the method described in any one of claims 1 to 9, the first access network device is used to implement the method described in any one of claims 10 to 16, and the second access network device is used to implement the method described in any one of claims 17 to 27.

31. A computer program product, characterized in that The invention comprises a computer program, which, when executed by a communication device, implements the method according to any one of claims 1 to 27.

32. A computer-readable storage medium, characterized in that: The storage medium stores a computer program or an instruction, and when the computer program or the instruction is executed by the communication device, the method according to any one of claims 1 to 27 is implemented.

33. A chip system, characterized in that: include: A processor configured to execute the method according to any one of claims 1 to 27.

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