Key processing method and related apparatus

Abstract

The present application provides a key processing method and a related apparatus. In response to a mobility LTM cell handover instruction triggered for layer 1 or 2, a terminal uses a first NCC value in a first handover procedure, wherein a target base station for the first handover procedure is a first base station; if the first handover procedure fails, when the first base station is selected as a target base station for a second handover procedure, an NCC value obtained on the basis of at least one of NCC processing indication information and the first NCC value is used in the second handover procedure. Because the target base station for both the first handover procedure and the second handover procedure is the first base station, the terminal and the first base station need to have consistent understanding of the use of the NCC value upon failure of the first handover procedure. Moreover, determining, on the basis of the NCC processing indication information and the first NCC value, the NCC value used in the second handover procedure helps the terminal and the first base station have consistent understanding of the use of the NCC value, so that a matching key is used to ensure normal use of the key, thereby performing normal communication.

Description

Key processing method and related device

[0001] The present application claims priority from the Chinese patent application No. 202411063709.6 filed on August 02, 2024, and entitled "Key processing method and related device", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the field of mobile communication technology, in particular to a key processing method and related device. BACKGROUND

[0003] In the field of mobile communication, in order to protect the security of communication, the terminal and the network use keys to communicate. In some business processes, it is necessary to configure and process the keys used by the terminal and the network to ensure that the keys are used normally and normal communication is carried out. SUMMARY

[0004] The present application provides a key processing method and related device to achieve the purpose of processing keys in LTM switching. The disclosed technical solution is as follows:

[0005] The first aspect of the present application provides a key processing method applied to a terminal, the method comprising: in response to a layer 1 or layer 2 triggered mobility LTM cell switching instruction, using a first key in a first switching process, the first key comprising a first NCC value, the target base station of the first switching process being a first base station, if the first switching process fails, in the case of selecting the first base station as the target base station of a second switching process, using a second key in the second switching process, the second key being based on at least one acquired NCC value of the first NCC value and NCC processing indication information, the NCC processing indication information being used to indicate the processing mode of the first NCC value. Because the target base stations of the first switching process and the second switching process are both the first base station, it is necessary for the terminal and the first base station to understand the use of the NCC value in the case of unsuccessful first switching process, and the NCC value used in the second switching process is determined based on the NCC processing indication information and the first NCC value, which is conducive to the understanding of the use of the NCC value by the terminal and the first base station, so that the matching key is used to ensure the normal use of the key, so that normal communication is carried out.

[0006] In some implementations, the NCC processing indication information indicates to retain the first NCC value, discard the first NCC value, or reset the value (i.e., a third NCC value). In practice, the NCC processing indication information can be configured as needed, thereby improving applicability and flexibility.

[0007] In some implementations, the NCC processing indication information indicates to retain the first NCC value, and the at least one acquired NCC value based on the NCC processing indication information and the first NCC value includes the first NCC value. The NCC value used in the failed handover is retained for use when switching to the first base station again, thereby facilitating full utilization of the NCC value.

[0008] In some implementations, the NCC processing indication information indicates to discard the first NCC value, and the at least one acquired NCC value based on the NCC processing indication information and the first NCC value includes a second NCC value different from the first NCC value. That is, the NCC value used in the failed handover is discarded, and the first NCC value is not used when switching to the first base station again.

[0009] In some implementations, the NCC processing indication information indicates a reset value, and the at least one acquired NCC value based on the NCC processing indication information and the first NCC value includes the reset value. The reset value is a third NCC value, which can be one of the NCC values configured for the first base station, and can or can not be the first NCC value. The NCC processing indication information indicating the reset value enables higher flexibility in the use of the NCC value.

[0010] In some implementations, before performing the second handover procedure, the method further includes: recording the first NCC value and identification information of the target base station of the first handover procedure, and the second key is determined based on the first NCC value, the identification information, and the NCC processing indication information, thereby facilitating the terminal to query the use of the NCC in the first handover procedure in subsequent handover, and thereby to determine the NCC value to be used in the subsequent handover procedure.

[0011] In some implementations, before receiving the LTM cell handover instruction, the method further includes: receiving key configuration information, the key configuration information including the NCC processing indication information. For example, the network can pre-configure the NCC processing indication information to the terminal, thereby laying a foundation for consistent understanding of the use of the NCC value by the terminal and the base station in the LTM handover.

[0012] In some implementations, the key configuration information is carried in an RRC reconfiguration message.

[0013] In some implementations, the key configuration information further includes: an NCC list corresponding to a candidate base station, the candidate base station including the first base station. Different candidate base stations can correspond to different NCC lists, thereby having higher flexibility, and the network can pre-configure the NCC list to the terminal, thereby laying a foundation for consistent understanding of the use of the NCC value by the terminal and the base station in the LTM handover.

[0014] In some implementations, the first NCC value used in the first handover procedure includes: selecting, from the NCC list corresponding to the first base station, a first NCC value that is not used in the handover procedure for the first handover procedure, so as to ensure higher security of communication.

[0015] In some implementations, the method further includes: in a case where the second base station is selected as a target base station of the second handover procedure, selecting, from the NCC list corresponding to the second base station, a fourth NCC value that is not used in the handover procedure for the second handover procedure, the second base station being different from the first base station. That is, in a case where the target base station of the second handover procedure is different from that of the first handover procedure, the NCC value used in the second handover procedure is selected from the NCC values corresponding to the target base station (i.e., the second base station) of the second handover procedure, and it can be seen that the NCC values used by different base stations and the selection of the NCC values are decoupled (independent of each other), and have higher flexibility and security.

[0016] In some implementations, the method further includes: after the first handover procedure, sending, to the core network device, information of the candidate base stations and usage information of the NCC in the first handover procedure, the usage information of the NCC in the first handover procedure including the first NCC value and NCC processing indication information. The NCC values can be shared by the candidate base stations, and in this case, the terminal sends, to the core network device, the information of the candidate base stations and the usage information of the NCC in the first handover procedure, thereby laying a foundation for the core network to issue the usage information of the NCC in the first handover procedure to the candidate base stations, and further laying a foundation for the candidate base stations and the terminal to understand the usage of the NCC values, which is conducive to the terminal and the target base station using matching keys in the LTM handover procedure.

[0017] In some implementations, the method further includes: if the first handover procedure is successful, sending, to the core network device, the information of the candidate base stations. The NCC values can be shared by the candidate base stations, and in this case, if the handover procedure is successful, the information of the candidate base stations is sent to the core network device, so that the core network device can synchronize the usage information of the NCC in the handover procedure to the candidate base stations, which is conducive to the terminal and the target base station using matching keys in the LTM handover procedure.

[0018] The second aspect of the present application provides a key processing method applied to a target base station of LTM switching, the method comprising: in response to an LTM cell switching instruction, using a first key in a first switching process in which a terminal switches to the target base station, the first key comprising a first NCC value; in the case of a failure of the first switching process, using a second key in a second switching process in which the terminal switches to the target base station, the second key comprising an NCC value obtained based on at least one of NCC processing indication information and the first NCC value, the NCC processing indication information being used to indicate a processing manner of the first NCC value. Since the target base station of the first switching process and the target base station of the second switching process are both the first base station, it is necessary to ensure that the terminal and the first base station have a consistent understanding of the use of the NCC in the case of a failure of the first switching process, and the NCC value used in the second switching process is determined based on the NCC processing indication information and the first NCC value, which is conducive to ensuring that the terminal and the first base station have a consistent understanding of the use of the NCC, thereby using a matching key to ensure normal use of the key and thus normal communication.

[0019] In some implementations, the NCC processing indication information indicates that the first NCC value is reserved; and the NCC value obtained based on at least one of the NCC processing indication information and the first NCC value comprises the first NCC value. Reserving the NCC value used in the failed switching is conducive to achieving sufficient use of the NCC value.

[0020] In some implementations, the NCC processing indication information indicates that the first NCC value is discarded; and the NCC value obtained based on at least one of the NCC processing indication information and the first NCC value comprises a second NCC value different from the first NCC value.

[0021] In some implementations, the NCC processing indication information indicates a reset value; and the NCC value obtained based on at least one of the NCC processing indication information and the first NCC value comprises a reset value, the reset value being a third NCC value. The NCC processing indication information indicating the reset value has higher flexibility.

[0022] In some implementations, before the second switching process is performed, the method further comprises: recording the first NCC value and identification information of the target base station of the first switching process, and the second key is determined based on the first NCC value, the identification information, and the NCC processing indication information, which is conducive to enabling the target base station of the first switching process to query the use of the NCC in the first switching process in subsequent switching, and thus to determine the NCC value to be used in the subsequent switching process.

[0023] In some implementations, before receiving the LTM cell switching instruction, further comprising: configuring the source base station of the LTM switching with NCC processing indication information, thereby laying a foundation for the source base station to configure the terminal with NCC processing indication information, and each candidate base station can configure its own NCC processing indication information, with higher flexibility.

[0024] In some implementations, the LTM cell switching instruction carries NCC processing indication information. That is, the source base station configures the target base station with NCC processing indication information, laying a foundation for the NCC value selected by the target base station to be the same as the NCC value selected by the terminal.

[0025] In some implementations, further comprising: sending the use information of the NCC in the first switching process to the candidate base stations of the LTM. In the case where the NCC values are shared by the candidate base stations, the target base station of the LTM switching needs to send the use information of the NCC in the first switching process to the other candidate base stations, so that the other candidate base stations can use the key matching the key used by the terminal in the case of being the target base station of subsequent switching.

[0026] In some implementations, the use information of the NCC includes: the use information of the NCC in the first switching process, or the unused NCC value in the pre-configured NCC value corresponding to the target base station, or the NCC value used for switching to the target base station again. The use information of the NCC is conducive to the candidate base stations using the key matching the key used by the terminal in subsequent switching.

[0027] In some implementations, the first switching process fails, the use information of the NCC in the first switching process includes: the NCC value used in the first switching process and the NCC processing indication information, so that the target base station and the terminal are consistent in processing the NCC value, the first switching process succeeds, and the use information of the NCC in the first switching process includes: the NCC value used in the first switching process. The NCC value used in the successful switching process is used as the used NCC value, and is not used in subsequent processes, so there is no need to send the NCC processing indication information again, which can save resources.

[0028] In some implementations, further comprising: in the case where the first switching process succeeds, sending the NCC value (i.e. the first NCC value) used in the first switching process to the core network device. In the case where the NCC values are shared by the candidate base stations, the core network device can be informed of the NCC value used in the switching process, which is conducive to the core network device synchronizing the use information of the NCC value to each candidate base station, thereby laying a foundation for each candidate base station to select a consistent NCC value with the terminal in the case of being the target base station.

[0029] The third aspect of the present application provides a key processing method applied to a source base station of LTM switching, the method comprising: configuring a terminal with key information corresponding to candidate base stations, the key information comprising NCC processing indication information; sending an LTM cell switching instruction to the terminal, the LTM cell switching instruction instructing the terminal to initiate a first switching process of switching to a first base station, a first key being used in the first switching process, the first key comprising a first NCC value, wherein at least one of the NCC processing indication information and the first NCC value is used to indicate a processing manner of the first NCC value, and in a case where the first switching process fails, the NCC processing indication information is used to obtain a second key used in a second switching process, the second key comprising a second NCC value, the first switching process and the second switching process having a same target base station. The NCC processing indication information configured by the source base station to the terminal lays a foundation for the terminal to select an NCC value in a second switching process of switching to the same target base station after the first switching process fails, and is conducive to the consistent understanding of the terminal and the target base station of the use of the NCC value, so that a matching key is used, to ensure normal use of the key and normal communication.

[0030] In some implementations, before the NCC processing indication information is configured to the terminal, the method further comprises: receiving the NCC processing indication information sent by the target base station. That is, the source base station indicates the NCC processing indication information configured by the target base station to the source base station to the terminal, to lay a foundation for the use of a matching key between the terminal and the target base station.

[0031] In some implementations, after the LTM cell switching instruction is sent to the terminal, the method further comprises: sending the NCC processing indication information to the target base station. That is, the NCC processing indication information does not need to be configured by each candidate base station itself, but is configured by the source base station to the target base station, to lay a foundation for the use of a matching key between the terminal and the target base station.

[0032] In some implementations, after the LTM cell switching instruction is sent to the terminal, the method further comprises: sending information of the candidate base stations to the target base station, so that the target base station can send information of the use of NCC in the switching process to the candidate base stations.

[0033] In some implementations, after the LTM cell switching instruction is sent to the terminal, the method further comprises: sending information of the candidate base stations to a core network device. In a case where the NCC values are shared by the candidate base stations, the core network device can send information of the use of NCC in the switching process to the candidate base stations.

[0034] In some implementations, the first handover procedure fails; and after sending the LTM cell handover instruction to the terminal, the method further includes: sending the first NCC value and the NCC processing indication information to the core network device. In the case where the NCC values are shared by the respective candidate base stations, because the first handover procedure fails, the NCC value and the NCC processing indication information used in the first handover procedure are sent by the source base station rather than the target base station to the core network device, which is conducive to obtaining more accurate NCC value and NCC processing indication information used in the first handover procedure.

[0035] In some implementations, before configuring the key information corresponding to the candidate base stations for the terminal, the method further includes: receiving the NCC list sent by the core network device, the NCC list including the NCC values shared by the candidate base stations. That is, the NCC values shared by the respective candidate base stations are issued by the core network device to the source base station without forwarding between the respective candidate base stations, which has higher communication efficiency.

[0036] The fourth aspect of the present application provides a key processing method applied to a core network device, the method including: sending a plurality of NCC values to a source base station of an LTM, receiving key configuration information, the key configuration information including: information of candidate base stations of the LTM, and usage information of NCC in a first LTM handover procedure, and sending at least one of two kinds of unused NCC values or next usage NCC values to the candidate base stations, the unused NCC values being NCC values in the plurality of NCC values that are not used in the first LTM handover procedure, and the next usage NCC values being NCC values used in a next LTM handover procedure of the first LTM handover procedure. It can be seen that the core network device can configure shared NCC values for the candidate base stations, and indicate at least one of two kinds of unused NCC values or next usage NCC values, which lays a foundation for consistent understanding of NCC usage by base stations and terminals in LTM handover.

[0037] In some implementations, the first LTM handover procedure succeeds, and the receiving of the key configuration information includes: receiving the identification of the candidate base stations sent by the source base station of the first LTM handover procedure, and receiving the NCC value used in the first LTM handover procedure sent by the target base station of the first LTM handover procedure. It can be seen that the usage of the NCC is obtained from the source base station and the target base station, which lays a foundation for indicating at least one of two kinds of unused NCC values or next usage NCC values of the candidate base stations.

[0038] In some implementations, the first LTM handover procedure fails, and the receiving of the key configuration information includes: receiving the key configuration information sent by the source base station of the first LTM handover procedure, the key configuration information including: the identification of the candidate base stations, the NCC value used in the first LTM handover procedure, and the NCC processing indication information. In the case of handover usage, the key configuration information is sent by the source base station to the core network device, which is conducive to obtaining more accurate key configuration information.

[0039] The fifth aspect of the present application provides a terminal, comprising one or more processors, a memory and a touch screen; the memory is used to store program code; the processor is used to run the program code, so that the terminal implements the key processing method provided by the first aspect of the present application.

[0040] The sixth aspect of the present application provides a base station, comprising a processor and a memory, the memory is used to store program code; the processor is used to run the program code, so that the base station implements the key processing method provided by the second aspect or the third aspect of the present application.

[0041] The seventh aspect of the present application provides a core network device, comprising a processor and a memory, the memory is used to store program code; the processor is used to run the program code, so that the core network device implements the key processing method provided by the fourth aspect of the present application.

[0042] The eighth aspect of the present application provides a computer readable storage medium, which stores instructions, when the instructions run on an electronic device, the electronic device executes the key processing method provided by the first aspect, the second aspect, the third aspect or the fourth aspect of the present application.

[0043] The ninth aspect of the present application provides a computer program product, which stores instructions, when the computer program product runs on an electronic device, the electronic device implements the key processing method provided by the first aspect, the second aspect, the third aspect or the fourth aspect of the present application.

[0044] The tenth aspect of the present application provides a chip system, comprising: at least one processor and an interface, the interface is used to receive code instructions and transmit to the at least one processor; the at least one processor runs the code instructions to implement the key processing method provided by the first aspect, the second aspect, the third aspect or the fourth aspect of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0045] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description. Obviously, the drawings described below are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0046] Fig. 1 is a structural schematic diagram of a base station of a 5G network;

[0047] Fig. 2 is an example diagram of keys needed to be used for communication between a terminal and a network;

[0048] Fig. 3 is an example diagram of a process of interaction between a terminal and a network to obtain keys;

[0049] FIG. 4 is a flowchart of an LTM in a base station;

[0050] FIG. 5 is a flowchart of configuration of key information in an LTM between base stations according to an embodiment of the present application;

[0051] FIG. 6a is a flowchart of a method of processing a key according to an embodiment of the present application;

[0052] FIG. 6b is a flowchart of another method of processing a key according to an embodiment of the present application;

[0053] FIG. 6c is a flowchart of another method of processing a key according to an embodiment of the present application;

[0054] FIG. 6d is a flowchart of another method of processing a key according to an embodiment of the present application;

[0055] FIG. 7 is a flowchart of another method of processing a key according to an embodiment of the present application;

[0056] FIG. 8a is a flowchart of another method of processing a key according to an embodiment of the present application;

[0057] FIG. 8b is a flowchart of another method of processing a key according to an embodiment of the present application;

[0058] FIG. 8c is a flowchart of another method of processing a key according to an embodiment of the present application;

[0059] FIG. 9a is a flowchart of another method of processing a key according to an embodiment of the present application;

[0060] FIG. 9b is a flowchart of another method of processing a key according to an embodiment of the present application;

[0061] FIG. 9c is a flowchart of another method of processing a key according to an embodiment of the present application;

[0062] FIG. 10 is a structural diagram of a terminal according to an embodiment of the present application;

[0063] FIG. 11 is a structural diagram of a base station according to an embodiment of the present application. DETAILED DESCRIPTION

[0064] The terms "first", "second", and "third" and the like in the description and claims of the present application and the appended drawings are used for distinguishing between similar objects and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and are

[0065] In the embodiments of the present application, the words "in some embodiments", "for example", "for instance", etc. are used to indicate an example, an illustration or a description. Any embodiment or design solution described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or having more advantages than other embodiments or design solutions. In fact, the words "exemplary" or "for example" are used in the specific way to present the relevant concept.

[0066] The technical solutions provided by the embodiments of the present application are applied to a mobile communication system, which comprises a terminal and a network. The network comprises an access network device and a core network device.

[0067] The mobile communication system includes, but is not limited to, a Long Term Evolution (LTE) system, an LTE Frequency Division Duplex (FDD) system, an LTE Time Division Duplex (TDD) system, a Universal Mobile Telecommunications System (UMTS), a Worldwide Interoperability for Microwave Access (WiMAX) communication system, a UMTS Terrestrial Radio Access Network (UTRAN) system, or a Global System for Mobile Communication (GSM) / Enhanced Data Rates for GSM Evolution (EDGE) system radio access network (GSM EDGE Radio Access Network, GERAN) system. In addition, the technical solutions provided by the embodiments of the present application can also be applied to any other wireless communication system with similar structure and function, such as a Public Land Mobile Network (PLMN) system, a 5th Generation (5G) communication system, a communication system after 5G, a New Radio Access Technology (NR) system, a Vehicle-to-X (V2X) system, etc.The V2X system can include a vehicle-to-network (V2N) system, a vehicle-to-vehicle (V2V) system, a vehicle-to-infrastructure (V2I) system, a vehicle-to-pedestrian (V2P) system, a long term evolution-vehicle (LTE-V) system, a vehicle-to-everything (V2X) system, a machine type communication (MTC) system, an internet of things (IoT) system, a long term evolution-machine (LTE-M) system, a machine-to-machine (M2M) system, and the like, and embodiments of the present application do not make any limitation thereto.

[0068] The access network device can be, but is not limited to, a device with wireless transceiving function. Specifically, it can be, but is not limited to, an evolved Node B (eNB or e-NodeB) in LTE, a base station (gNodeB or gNB) or a transmission receiving point (TRP) in NR, a radio access network (RAN) device, a base station of subsequent evolution of 3GPP, an access node in a WiFi system, a wireless relay node, a wireless backhaul node, and the like. The access network device can also be a wireless controller, a centralized unit (CU), and / or a distributed unit (DU) in a cloud radio access network (CRAN) scenario. The network device can also be a server, a wearable device, or a vehicle-mounted device, and the like.

[0069] The base station can be a macro base station, a micro base station, a pico base station, a femto base station, a relay station, a balloon station, and the like. The plurality of base stations can support the same type of network mentioned above or different types of networks mentioned above. The base station can include one or more co-sited or non-co-sited TRPs.

[0070] As shown in FIG. 1, the base station of the 5G network includes a centralized unit (CU) and a distributed unit (DU). The CU and the DU are divided according to different protocol layers. The DU is responsible for the physical layer, the medium access control (MAC) layer, and the radio link control (RLC) layer. The CU is responsible for the packet data convergence protocol (PDCP) layer and the radio resource control (RRC) layer.

[0071] When the access network device is multiple, the multiple access network devices can be the same type of access network device, or different types of access network devices. The access network device can communicate with the terminal device, or communicate with the terminal device through the relay station. The terminal device can communicate with multiple access network devices of different technologies, for example, the terminal device can communicate with a base station supporting an LTE network, and can also communicate with a base station supporting a 5G network. It can also support dual connectivity with the base station of the LTE network and the base station of the 5G network.

[0072] The terminal can include a handheld device with wireless transceiver function, or a vehicle-mounted device, etc., and can be, but is not limited to, a mobile phone, a mobile phone, a tablet computer, a palm computer, a laptop computer, a notebook computer, a computer with wireless transceiver function, a mobile internet device (MID), a wearable device, a virtual reality (VR) device, an augmented reality (AR) device, a wireless terminal in industrial control, a terminal device in a vehicle-mounted terminal, a wireless terminal in self-driving, a wireless terminal in remote medical surgery, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal device in a 5G network, or a terminal device in a future evolved public land mobile network (PLMN), etc. The embodiments of the present application are not limited thereto.

[0073] By way of example and not limitation, in the embodiments of the present application, the terminal can also be a wearable device. The wearable device can also be referred to as a wearable smart device, which is a general term for devices that are designed and developed by applying wearable technology to daily wear, such as glasses, gloves, watches, clothing, and shoes. The wearable device is a portable device that is directly worn on the body or integrated into the user's clothes or accessories. The wearable device is not only a hardware device, but also a powerful function realized through software support and data interaction, cloud interaction. The general wearable smart device includes a full function, large size, and can realize complete or partial functions without relying on a smart phone, such as a smart watch, a smart helmet, or a smart glasses, etc., and only focuses on a certain application function, and needs to cooperate with other devices such as a smart phone, such as various smart wristbands, smart jewelry, etc.

[0074] In addition, in the embodiments of the present application, the terminal can also be a terminal device in an internet of things (IoT) system. The IoT is an important part of future information technology development, and its main technical feature is to connect objects through communication technology and network, so as to realize the intelligent network of man-machine interconnection and object-object interconnection.

[0075] The terminal device in the embodiments of the present application can also be referred to as an electronic device, a user equipment (UE), a mobile station (MS), a subscriber unit (SU), a mobile terminal (MT), an access terminal, an access terminal device, a vehicle-mounted terminal, an industrial control terminal, a UE unit, a UE station, a subscriber unit, a subscriber station, a mobile station, a mobile station, a remote station, a remote terminal, a remote terminal device, a mobile device, a user terminal, a UE terminal device, a terminal, a wireless communication device, a user agent, a UE agent, a UE device, or a user device, etc.

[0076] The embodiments of the present application provide a technical solution for configuring a key used in a Layer 1 or 2 triggered mobility (LTM) process. In order to better illustrate the technical solution provided by the embodiments of the present application, the related content of the key and LTM is first described.

[0077] FIG. 2 is an example of various keys required for communication between a terminal and a network, and an example of the derivation relationship between the various keys. In FIG. 2, K SEAF denotes an anchor key, which is obtained by the terminal and a security anchor function (SAF) network element together. K AMF denotes a key based on K SEAF and obtained by the terminal and a mobility management function (AMF) network element. K RRC-enc denotes a radio resource control (RRC) signaling encryption key, K RRC-int denotes an RRC signaling integrity protection key. K UP-enc denotes a data plane (UP) data encryption key, K UP-int denotes a UP data integrity protection key. NH denotes a next hop parameter, and NCC denotes a link counter in NH.

[0078] In the embodiments, K gNB* is referred to as a first key, and K gNBThe second key is called K

[0079] The keys shown in FIG. 2 are some keys commonly used in communication between a terminal and a base station, which are only examples and do not represent all keys in the field of mobile communication. The arrows can represent the derivation relationship between the keys, for example, the first key K gNB* is obtained by the NCC, and the second key K gNB is obtained based on the first key K gNB* . AMF As can be seen from FIG. 2, based on K SEAF , other keys can be derived layer by layer.

[0080] In FIG. 2, the first key and the second key in the 4G communication system are taken as examples, in the 5G communication system, the first key is represented as K NG-RAN* , and the second key is represented as K NG-RAN . In the following embodiments, K gNB* and K gNB are taken as examples, and it can be understood that K gNB* may be replaced by K NG-RAN* , and K gNB may be replaced by K NG-RAN .

[0081] FIG. 3 is an example of a process in which a terminal and a network interact to obtain keys, including the following steps:

[0082] S101, the terminal obtains K SEAF in the process of security authentication with the network, and further derives K AMF .

[0083] The following is a process of performing security context establishment:

[0084] S102, the base station obtains the security capability information of the terminal from the AMF.

[0085] S103, the base station determines the security algorithm of the terminal based on the security capability information of the terminal.

[0086] S104, the terminal and the AMF perform a process of deriving K gNB and NH.

[0087] S105, the base station derives K gNB , an encryption key, and an integrity protection key.

[0088] It can be understood that K gNB obtained in S104 is the same as K gNB obtained in S105.

[0089] The signaling encryption key includes an encryption key of RRC signaling and an encryption key of UP data. The integrity protection key includes an integrity protection key of RRC signaling and an integrity protection key of UP data.

[0090] The key obtained in S105 is used for subsequent communication between the terminal and the base station.

[0091] LTM is a mobility enhancement technology. FIG. 4 is an example of a flow of LTM.

[0092] In FIG. 4, the source cell is a cell in which the terminal is located before handover, and the target cell is a cell in which the terminal is located after handover. The target cell is selected from candidate cells, and in FIG. 4, candidate cell 1 is taken as an example of the target cell. For selection of the target cell, refer to S210 in FIG. 4. In FIG. 4, two candidate cells are taken as an example, but the number of candidate cells is not limited.

[0093] Because it is intra-CU handover, the source cell and the candidate cell shown in FIG. 4 belong to the same CU. In FIG. 4, the terminal is already in a connected state.

[0094] In FIG. 4, the following steps are included:

[0095] S201. The terminal sends a measurement result to the source cell.

[0096] The terminal in the connected state is currently connected to the source cell, and the measurement result indicates the result of measurement of each candidate cell by the terminal. Specifically, layer (L) measurement reporting can be performed according to the configured candidate cell. The layer measurement reporting can include any one of layer 1 measurement reporting, layer 2 measurement reporting, or layer 3 measurement reporting. The candidate cell can refer to all adjacent cells that the terminal can access.

[0097] The source cell determines the support capability of the terminal for LTM according to the measurement result, and determines to perform LTM according to the support capability of the terminal for LTM, and performs a candidate cell configuration preparation process, including S202-S205.

[0098] S202. The source cell sends an LTM handover request message to candidate cell 1.

[0099] S203. Candidate cell 1 sends an LTM handover request response message to the source cell.

[0100] The LTM handover request response message sent by candidate cell 1 includes configuration information of candidate cell 1.

[0101] S204. The source cell sends an LTM handover request message to candidate cell 2.

[0102] S205. Candidate cell 2 sends an LTM handover request response message to the source cell.

[0103] The LTM handover request response message sent by the candidate cell 2 includes configuration information of the candidate cell 2.

[0104] S206, the source cell sends an RRC reconfiguration message to the terminal.

[0105] The RRC reconfiguration message includes configuration information of the subsequent cell 1 and configuration information of the candidate cell 2.

[0106] S207, the terminal sends an RRC reconfiguration complete message to the source cell.

[0107] The RRC reconfiguration complete message indicates that the terminal has received the RRC reconfiguration message.

[0108] S208, the terminal performs a downlink synchronization procedure for the candidate cell.

[0109] S209, the terminal performs an uplink synchronization procedure for the candidate cell.

[0110] In some implementations, the RRC reconfiguration information indicates that the terminal measures an uplink timing advance, the terminal measures a timing advance of the source cell, and determines a timing advance of the target cell according to a reception time difference between the source cell and the target cell.

[0111] In other implementations, a contention free random access (CFRA) is triggered by the source cell through a physical downlink control channel (PDCCH) order for obtaining a timing advance of the candidate cell, the terminal initiates the CFRA to the candidate cell to obtain the timing advance, and the network manages the validity of the timing advance.

[0112] S210, the terminal sends an L1 measurement reporting message to the source cell.

[0113] The terminal measures layer 1 (L1) of the source cell and layer 1 of the candidate cell respectively to obtain L1 measurement results, and the L1 measurement reporting message includes the L1 measurement results.

[0114] S211, the source cell sends an LTM handover instruction to the terminal.

[0115] The source cell selects a target cell from the candidate cells based on the L1 measurement reporting message, and the handover instruction instructs the terminal to switch from the source cell to the target cell.

[0116] In some implementations, the switching instruction comprises a MAC control element (CE). The MAC CE comprises at least the following information: a timing advance (TA), a transmission configuration indication (TCI) state id, CFRA resource information, and candidate cell configuration information id.

[0117] The TA is a TA obtained by the terminal and still in a valid state, i.e., before S211, if the network determines that the TA obtained by the terminal before is still in a valid state, the TA is included in the MAC CE.

[0118] S212, the terminal disconnects the connection with the source cell.

[0119] S213, the terminal performs a random access procedure with the target cell.

[0120] In an alternative way of S213, when the terminal receives the switching MAC CE, if the MAC CE carries a TA value, or when the terminal measures the TA by itself, the terminal initiates a switching without random access to the target cell, i.e., the terminal only needs to send an uplink signaling or a first uplink data packet to the target cell to indicate that the terminal has accessed the target cell.

[0121] S214, the terminal completes the LTM switching with the target cell.

[0122] The LTM procedure shown in FIG. 4 supports intra-CU switching.

[0123] It can be understood that before the switching procedure shown in FIG. 4 is performed, the terminal and the network have completed the negotiation and acquisition of the key as shown in FIG. 2. Since it is intra-CU switching, the source cell, the target cell and the candidate cell shown in FIG. 4 belong to the same CU, and therefore the switching between cells in the LTM procedure shown in FIG. 4 does not involve the problem of key update.

[0124] It is found that in order to improve the application range of LTM, it is a trend that LTM supports switching between different base stations. The switching between different base stations needs to consider the problem of key.

[0125] The research also finds that further improvements can be made to further improve the performance of the LTM, and one possible improvement is that the terminal implements continuous LTM switching after the LTM candidate cell is configured once. For example, after the terminal switches from the source base station to the first base station, the terminal does not need to be configured with a candidate cell, and can switch to the second base station. This includes the terminal switching from the source base station to the first base station failing, and then continuing to switch to the second base station.

[0126] To implement continuous LTM switching, the LTM technology still has at least the following problems to be solved: how to configure and update the key information. This problem includes the following specific aspects:

[0127] 1. Multiple LTM switching involves the connection of the terminal with different base stations, and can also involve multiple connections with the same base station. In order to ensure the security of communication, the terminal and the base station need to use a key for communication. Therefore, how to configure different keys for multiple connections with the base station in multiple switching is a problem to be solved.

[0128] To solve problem 1, in some implementations, as shown in FIG. 5, the key information configuration process includes the following steps:

[0129] S301, the terminal sends the measurement result to the base station 1.

[0130] The terminal in the connected state is currently connected to the base station 1, and reports the measurement result of measuring each candidate cell to the base station 1.

[0131] The base station 1 acts as the source base station, determines the support capability of the terminal for LTM according to the measurement, and determines to perform LTM according to the support capability of the terminal for LTM, and performs the candidate cell configuration preparation process, including S302-S305.

[0132] S302, the base station 1 sends an LTM switching request to the base station 2.

[0133] In order to support the key requirement of multiple connections with the base station 2 in multiple switching, in this step, the LTM switching request includes a key list configured for the base station 2, and the key list includes multiple groups of keys configured for the base station 2. Any group of keys includes a corresponding first key K gNB* value and NCC value. The corresponding first key value and NCC value can be understood as: the first key value is generated from the NCC value, that is, the first key value corresponds to the NCC value. The terminal can obtain the first key K gNB* value and NCC value based on the derivation relationship of FIG. 2, for example, and the specific process is not within the scope of discussion of the present application, which will not be described here.

[0134] For convenience of description, the LTM handover request sent by the base station 2 in this step is referred to as a first handover request, and the key list in the first handover request is referred to as a first key list, which is represented as (K gNB* , NCC) list1 in FIG. 5.

[0135] S303, the base station 2 sends an LTM handover request response to the base station 1.

[0136] The LTM handover request response includes an NCC list. The NCC list includes NCC values in the multiple groups of keys configured for the base station 2.

[0137] The LTM handover request response sent by the base station 2 is referred to as a first handover request response, and the NCC list in the first handover request response is referred to as a first NCC list, which is represented as NCC list1 in FIG. 5.

[0138] S304, the base station 1 sends an LTM handover request to the base station 3.

[0139] To support the key requirement for multiple connections with the base station 3 that can occur in multiple handovers, the LTM handover request in this step includes a key list configured for the base station 3, and the key list includes multiple groups of keys configured for the base station 3. Any group of keys includes a corresponding first key K gNB* value and an NCC value.

[0140] The LTM handover request sent to the base station 3 is referred to as a second handover request, and the key list in the second handover request is referred to as a second key list, which is represented as (K gNB* , NCC) list2 in FIG. 5.

[0141] The first key list and the second key list can be the same or different. That is, the key lists sent by the source base station to the candidate base stations can be the same or different.

[0142] S305, the base station 3 sends an LTM handover request response to the base station 1.

[0143] The LTM handover request response includes an NCC list.

[0144] The LTM handover request response sent by the base station 3 is referred to as a second handover request response, and the NCC list in the second handover request response is referred to as a second NCC list, which is represented as NCC list2 in FIG. 5. The second NCC list includes NCC values in the multiple groups of keys configured for the base station 3.

[0145] S306, the base station 1 sends an RRC reconfiguration message to the terminal.

[0146] The RRC reconfiguration message includes: a first key list, an identifier of base station 2 corresponding to the first key list, a second key list, and an identifier of base station 3 corresponding to the second key list.

[0147] It can be understood that because the terminal may also select a cell of base station 1 (that is, base station 1 is also a target base station) when selecting a target cell for handover, the RRC reconfiguration message further includes: a key list used by base station 1 (that is, a third key list) and an identifier of base station 1 corresponding to the third key list (not shown in FIG. 5).

[0148] The identifier of the base station corresponding to the key list is used to facilitate the terminal to distinguish the key lists configured by different base stations, so as to select the key in the key list corresponding to a target base station for use when subsequently switching to the target base station.

[0149] S307, the terminal sends an RRC reconfiguration complete message to base station 1.

[0150] The RRC reconfiguration complete message indicates that the terminal has received the RRC reconfiguration message.

[0151] As can be seen from the flow shown in FIG. 5, the source base station configures multiple sets of keys for the candidate base stations and the terminal respectively to support the encryption requirement of multiple connections with the base stations in multiple LTM handovers.

[0152] Further research has found that even based on the flow shown in FIG. 5, there are still some problems:

[0153] 2. Continuous switching is to improve the switching performance of LTM, such as improving the switching efficiency, and if the network needs to configure key information to the terminal before each switching (such as S306 and S307 shown in FIG. 5), the effect of improving the switching efficiency is limited, and there is also a large signaling overhead. Therefore, how to support multiple continuous switching by configuring key information to the terminal once is a problem to be solved.

[0154] 3. Based on the technology of supporting multiple continuous switching by configuring key information to the terminal once, how to ensure that the terminal and the network understand the keys consistently during continuous multiple switching, so that the terminal and the network use matching keys for communication to ensure normal communication is a problem to be solved.

[0155] In view of the above technical problems 2 and 3, an embodiment of the present application provides a key processing method, as shown in FIG. 6a, assuming that the terminal is currently connected with base station 1, that is, base station 1 is a source base station, and base station 2 and base station 3 are candidate base stations.

[0156] The following steps are included in FIG. 6a:

[0157] S401. The terminal sends a measurement result to the base station 1.

[0158] S402. The base station 1 sends an LTM handover request message (i.e., a first handover request message) to the base station 2.

[0159] The first handover request message includes a first key list configured for the base station 2, which can be seen in S302.

[0160] S403. The base station 2 sends an LTM handover request response (i.e., a first handover request response) to the base station 1.

[0161] Compared with FIG. 5, the first handover request response includes a first NCC list and NCC processing indication information.

[0162] To improve security, a set of keys is used to communicate with a base station each time the terminal successfully switches to the base station, and a new key needs to be used when the terminal switches to the base station again. Therefore, if the terminal successfully switches to a base station, the key used this time is a used key and will not be used again. However, it can be understood that if the terminal fails to switch to a base station, the key used for this time of switching cannot be completely regarded as a used key. Therefore, the terminal and the base station need to form a consistent processing mode for the key used for the failed switching, so that the terminal and the base station use a matching key when the terminal switches to the base station next time.

[0163] The NCC processing indication information is used to indicate a processing mode for the NCC value. In combination with the LTM scenario, the NCC processing indication information indicates a processing mode for the NCC value used for the failed switching to a base station as a target base station in the LTM handover procedure. The NCC processing indication information is one of preconfigured processing indication information. The preconfigured processing indication information respectively indicates a reserved, discarded, and reset value. In FIG. 6a, the NCC processing information indicates the reserved value as an example.

[0164] The reserved can be understood as reserving the NCC value used for the failed switching as an unused NCC value, rather than a used NCC value, which can be continuously used subsequently.

[0165] Suppose that the target base station of the failed switching is the first base station, and the first NCC value is used for the failed switching. The reserved indicates that the first NCC value is still used for the switching to the first base station again.

[0166] The discarded can be understood as regarding the NCC value used for the failed switching as a used NCC value, which will not be used subsequently.

[0167] The discarding indicates that the re-handover to the first base station does not use the first NCC value but uses a second NCC value different from the first NCC value. The second NCC value is selected from the NCC list configured by the first base station to the source base station.

[0168] The reset value can be understood as a specified NCC value from which the subsequent handover starts to use.

[0169] The discarding indicates that the re-handover to the first base station does not use the first NCC value but uses a second NCC value different from the first NCC value. The second NCC value is selected from the NCC list configured by the first base station to the source base station.

[0170] In some implementations, the NCC processing indication information is a character or a numerical value, or a combination of a character and a numerical value.

[0171] It can be understood that the "NCC processing indication information" is only an example and can also be referred to as "NCC indication information", "NCC indication message", etc., and is not limited. Regardless of the name used, the function is to indicate the processing mode of the NCC value used in the failed handover.

[0172] S404, the base station 1 sends an LTM handover request message (i.e., a second handover request) to the base station 3.

[0173] S405, the base station 3 sends an LTM handover request response (i.e., a second handover request response) to the base station 1.

[0174] The second handover request response includes a second NCC list and NCC processing indication information.

[0175] It can be understood that the NCC processing indication information sent by the base station 2 and the NCC processing indication information sent by the base station 3 can be the same or different. In FIG. 6a, the NCC processing indication information sent by the base station 3 is also taken as an example of indicating reservation.

[0176] S406, the base station 1 sends an RRC reconfiguration message to the terminal.

[0177] The RRC reconfiguration message includes a key list of each candidate base station (the base station 2 and the base station 3, and the base station 1 can also be included) and the identity of the corresponding base station, which can be referred to S306.

[0178] In this step, the RRC reconfiguration message also includes NCC processing indication information of each base station.

[0179] The NCC processing indication information in the RRC reconfiguration message is the NCC processing indication information sent by each candidate base station to the source base station (i.e., base station 1). As the NCC processing indication information configured by base station 2 in S403 indicates reservation, the NCC processing indication information corresponding to the key list (i.e., the second key list) of base station 2 in the RRC reconfiguration message indicates reservation.

[0180] In FIG. 6a, it is assumed that the NCC processing indication information corresponding to each candidate base station indicates reservation, and therefore, the identifier of each candidate base station does not need to correspond to a "reservation". It can be understood that in the case that the candidate base stations correspond to different NCC processing indication information, the RRC reconfiguration message indicates the correspondence between the identifier of each candidate base station and the NCC processing indication information.

[0181] S407. The terminal sends an RRC reconfiguration complete message to the base station 1.

[0182] S408. The base station 1 sends an LTM cell switching instruction to the terminal.

[0183] It is assumed in this embodiment that the base station 1 selects the base station 2 as the target base station, and the LTM cell switching instruction indicates that the terminal switches from the base station 1 to the base station 2.

[0184] S409. The base station 1 sends an LTM cell switching instruction to the base station 2.

[0185] The LTM cell switching instruction is used to instruct the target base station to start switching.

[0186] S410. The terminal initiates a switching process from the base station 1 to the base station 2 in response to the LTM cell switching instruction.

[0187] It can be understood that if the switching to the base station 2 is initiated for the first time, it is the initial switching to the base station 2, and there is no recorded NCC value and switching result used for the switching to the base station 2, that is, the query history record is empty, and therefore, the NCC value used for the current switching is selected from the first NCC list configured by the base station 2 for the terminal. In some implementations, the NCC values are sequentially selected according to the order of the NCCs in the NCC list from small to large.

[0188] In this embodiment, it is assumed that the terminal selects NCC=1 and the K gNB* It is assumed that the switching fails, and in FIG. 6a, the switching failure is indicated by "X".

[0189] In this embodiment, the handover failure can be that the terminal does not switch to the target cell, or that the terminal switches to the target cell but a radio link failure (RLF) occurs within a short time period. The terminal determines whether the terminal has not switched to the target cell by starting a timer after receiving the LTM cell handover instruction, and determining whether the terminal has successfully switched to the target cell within a threshold time period recorded by the timer.

[0190] S411. The terminal records the NCC value used in the current handover and information indicating the handover failure.

[0191] In the example above, the terminal records the NCC value used in the current handover, i.e. NCC = 1, and the information indicating the handover failure.

[0192] In some implementations, the information indicating the handover failure is identification information of the target base station of the failed handover. In the example of this embodiment, the information indicating the handover failure is identification information of the base station 2.

[0193] In other implementations, the information indicating the handover failure can include other information in addition to the identification information of the target base station of the failed handover, such as a time stamp of the failed handover, or information of a target cell under the target base station of the failed handover, and the like, which are not limited herein.

[0194] S412. The terminal selects a cell.

[0195] After the handover failure, the terminal needs to select a connectable cell. The terminal can select the cell according to a quality parameter of the cell, which is not described herein.

[0196] It can be understood that the cell selected by the terminal in this step can be a cell of the base station 2, or a cell of the base station 3 or the base station 1.

[0197] In this embodiment, it is assumed that the cell selected in this step belongs to the base station 2.

[0198] S413a. The terminal initiates a handover process to the base station 2.

[0199] The terminal selects the NCC value used in the current handover from the stored NCC list by querying the recorded content and the stored NCC processing instruction information.

[0200] Because NCC = 1 has been recorded in S411, and the corresponding handover result is the handover failure, and the NCC processing instruction information indicates to keep, the terminal still selects NCC = 1 from the first NCC list corresponding to the identification of the base station 2, and K gNB* .

[0201] It can be understood that the base station 2 performs the same selection as the terminal. Assuming that the current handover is successful, the terminal and the base station 2 both use NCC=1 and the corresponding K gNB* deduce the encryption key and the integrity protection key, and perform normal communication.

[0202] As can be seen from the flow shown in FIG. 6a, through the RRC reconfiguration message, the source base station sends the key information and the NCC processing indication information configured by each candidate base station to the terminal, so that the terminal has consistent key selection rules with the target base station in the continuous multiple handover processes, thereby ensuring that the terminal and the base station use matching keys for communication, and the signaling overhead can also be saved because the keys do not need to be configured before each handover.

[0203] In FIG. 6a, taking the case of reserving as an example, an alternative way is shown in FIG. 6b: the NCC processing indication information indicates discarding, and in the handover in S413a, the terminal selects NCC=2 and the K gNB* corresponding to NCC=2 from the first NCC list corresponding to the identifier of the base station 2. It can be understood that discarding means that NCC=1 is no longer used, and here, taking the case of sequentially selecting NCC=2 as an example, but this is not a limitation, and other unused NCC values in the first NCC list can also be selected. The base station 2 also selects NCC=3 and the K gNB* .

[0204] Another alternative way is shown in FIG. 6c: the NCC processing indication information indicates a reset value, and assuming that the reset value is 5, in S413a, the terminal selects NCC=5 and the K gNB* corresponding to NCC=5 from the first NCC list corresponding to the identifier of the base station 2. The base station 2 also selects NCC=5 and the K gNB* .

[0205] It should be noted that in the drawings of the embodiments of the present application, the used NCC values are taken as examples, and the first keys corresponding to the NCC values are not shown, but it can be understood that in actual use, the NCC values and the first keys corresponding to the NCC values are used.

[0206] FIG. 6d is another key processing method provided by the embodiments of the present application, and the difference from FIGS. 6a-6c is that in S412, after the terminal fails to perform handover to the base station 2, the terminal selects the cell of the base station 3, and in this case, in S413b, the terminal initiates handover to the base station 3, assuming that the terminal initiates handover to the base station 3 for the first time, and is preconfigured to use the NCC values in the second NCC list in the order from small to large, then in the handover in S413b, the terminal and the base station 3 both select NCC=1 and the KgNB* .

[0207] Based on Fig. 6d, assuming that the handover in S413b is successful, the terminal records the NCC=1 used in this handover and the result indicating the success of the handover, or, the NCC=1 and the corresponding K gNB* is marked as used.

[0208] Based on the flow shown in Fig. 6d, if the terminal subsequently performs handover to the base station 2 again, the key is selected according to S413a shown in Fig. 6a. In Fig. 6a, the handover to the base station 2 twice in succession is taken as an example, and the handover to the base station 2 again described herein is discontinuous from the last handover to the base station 2.

[0209] In addition to the flows shown in Figs. 6a-6d, it is also possible that the source cell where the terminal is located experiences RLF, and the terminal does not receive the LTM cell handover instruction, in which case, the terminal does not perform the first handover, and does not affect the selection of the NCC.

[0210] Fig. 7 is another method for processing key information provided by an embodiment of the present application, which is different from the flows shown in Figs. 6a-6d in that the NCC processing indication information is provided by the source base station.

[0211] Fig. 7 includes the following steps:

[0212] S501. The terminal sends a measurement result to the base station 1.

[0213] S502. The base station 1 sends an LTM handover request message (i.e., a first handover request message) to the base station 2.

[0214] S503. The base station 2 sends an LTM handover request response (i.e., a first handover request response) to the base station 1.

[0215] S504. The base station 1 sends an LTM handover request message (i.e., a second handover request) to the base station 3.

[0216] S505. The base station 3 sends an LTM handover request response (i.e., a second handover request response) to the base station 1.

[0217] In this embodiment, the LTM handover request responses returned by the base station 2 and the base station 3 do not include the NCC processing indication information, but the NCC processing indication information is configured by the base station 1 as the source base station, which will be described in subsequent steps.

[0218] S506. The base station 1 sends an RRC reconfiguration message to the terminal.

[0219] In this embodiment, the RRC reconfiguration message includes the key list of each base station (the base station 1, the base station 2, and the base station 3), the NCC processing indication information, and the identity of the corresponding base station.

[0220] In this step, the base station 1 can configure different NCC processing indication information for the key list of the base station 2 and the base station 3, or can configure the same NCC processing indication information. The NCC processing indication information of the base station 1 and the base station 2 or the base station 3 can be the same or different.

[0221] In FIG. 7, the NCC processing indication information of each base station indicates discarding as an example.

[0222] S507. The terminal sends an RRC reconfiguration complete message to the base station 1.

[0223] S508. The base station 1 sends an LTM cell switching instruction to the terminal.

[0224] In this embodiment, it is assumed that the base station 1 selects the base station 2 as the target base station, and the LTM cell switching instruction indicates that the terminal switches from the base station 1 to the base station 2.

[0225] S509. The base station 1 sends NCC processing indication information to the target base station.

[0226] In this embodiment, the processing mode indicated by the NCC processing indication information is reserved, discarded, or reset value. In FIG. 7, discarding is taken as an example.

[0227] It can be understood that the NCC processing indication information in this step is the same as the processing indication information in S506, that is, the source base station configures the same NCC processing indication information to the terminal and the target base station, so as to ensure that the terminal and the target base station use matching keys.

[0228] The base station 1 can use the signaling in the existing communication standard, such as the LTM cell switching instruction sent to the target base station, or use the signaling that can be newly written in the standard in the future, to indicate the NCC processing indication information to the target base station.

[0229] S510. The terminal fails to switch from the base station 1 to the base station 2.

[0230] In this embodiment, the terminal uses NCC=2 in the NCC list corresponding to the base station 2 and the corresponding first key in the switching process of this step as an example.

[0231] S511. The terminal records that NCC=1 of the base station 2 is used in this switching, and information indicating that the switching fails.

[0232] S512. The terminal performs cell selection.

[0233] It is assumed here that the terminal still selects the cell of the base station 2.

[0234] S513. The terminal switches from the base station 1 to the base station 2.

[0235] Because the NCC processing indication information configured by the source base station indicates discarding, in the case of handover failure in S510, in the flow of handover from base station 1 to base station 2 again in this step, neither the terminal nor base station 2 uses NCC=1, but uses other unused NCC. In FIG. 7, NCC=2 and the corresponding first key are taken as an example.

[0236] It can be understood that an alternative way is that in S506 and S509, the configured NCC processing indication information indicates reservation, and in S513, the terminal and base station 2 select NCC=1 and the corresponding first key.

[0237] Another alternative way is that in S506 and S509, the configured NCC processing indication information indicates resetting value, such as NCC=5, and in S513, the terminal and base station 2 select NCC=5 and the corresponding first key.

[0238] The flow shown in FIG. 7 configures the NCC processing indication information corresponding to each candidate base station for the terminal by the source base station, and sends the NCC processing indication information to the target base station after sending the LTM cell handover instruction, without pre-configuration of the candidate base station.

[0239] FIG. 8a provides another key processing method according to an embodiment of the present application. Compared with the foregoing embodiments, the difference lies in the following scenario of sharing keys by each candidate base station: the core network configures an NCC list for the terminal, which is shared and used by each candidate base station of the terminal. The core network provides the NCC list to the source base station, the source base station generates a key corresponding to each candidate base station based on the NCC list, and sends the key and the corresponding NCC value to each candidate base station. The NCC list shared by each candidate base station and the corresponding key are sent to the terminal through the RRC reconfiguration message. In FIG. 8a, before the initial handover (i.e., the first handover) flow, base station 1 is the source base station, and base station 2 and base station 3 are candidate base stations.

[0240] In this scenario, in this embodiment, the use of NCC is exchanged between base stations.

[0241] FIG. 8a includes the following steps:

[0242] S601, the AMF sends an NCC list to base station 1.

[0243] The shared NCC list includes multiple NCC values, which are arranged in order, and examples of the multiple NCC values are: 1, 2, 3, ….

[0244] In some implementations, the terminal and the base station are pre-configured with the usage of the NCC list: the NCCs are used in the order of the ascending NCC values, i.e., NCC = 1 is used first, then NCC = 2, and then NCC = 3.

[0245] In this step, the difference from the above embodiment is that each candidate base station (e.g., base station 2 and base station 3 as shown in FIG. 8a) shares the NCC list.

[0246] In this embodiment, it is assumed that base station 1 is the source base station, and therefore the AMF configures the shared NCC list to the source base station.

[0247] It can be understood that the AMF is taken as an example for illustration in FIG. 8a, but this does not constitute a limitation, and the shared NCC list can also be configured by other network elements of the core network.

[0248] S602. The terminal sends the measurement result to base station 1.

[0249] S603. Base station 1 sends an LTM handover request message (i.e., a first handover request message) to base station 2.

[0250] In this embodiment, the LTM handover request message sent by the source base station to the other base station includes a key list.

[0251] The key list includes a plurality of groups of keys, and each group of keys includes a corresponding first key K gNB* value and an NCC value. The NCC value is one of the shared NCC list sent by the AMF in S601, and the first key K gNB* value corresponding to the NCC value is a first key K gNB* value generated using the NCC value.

[0252] S604. Base station 2 sends an LTM handover request response (i.e., a first handover request response) to base station 1.

[0253] In this embodiment, the first handover request response does not include NCC processing indication information.

[0254] The first handover request response includes an NCC list, and the NCC list includes the NCC in the key list, i.e., the shared NCC list.

[0255] S605. Base station 1 sends an LTM handover request message (i.e., a second handover request) to base station 3.

[0256] The second handover request includes a key list.

[0257] It can be understood that, because each base station shares the NCC list, a plurality of first keys K gNB*The value is the same, and thus the key list sent by the base station 1 to the base station 2 and the base station 3 is the same, referred to herein as a shared key list.

[0258] S606, the base station 3 sends an LTM handover request response (i.e., a second handover request response) to the base station 1.

[0259] The NCC processing indication information is not included in the second handover request response.

[0260] The NCC list is included in the second handover request response, and the NCC list includes the NCC in the shared key list, i.e., the shared NCC list.

[0261] S607, the base station 1 sends an RRC reconfiguration message to the terminal.

[0262] In this step, the RRC reconfiguration message includes the shared key list and the NCC processing indication information.

[0263] The NCC processing indication information indicates reservation, discard, or reset. In FIG. 8a, the NCC processing indication information indicates reservation as an example.

[0264] In this embodiment, because the base stations use the shared NCC list, the keys used by the respective base stations are the same (i.e., the shared key list), and thus the RRC reconfiguration message does not need to include the correspondence between the respective base stations and the identifiers of the key lists.

[0265] S608, the terminal sends an RRC reconfiguration complete message to the base station 1.

[0266] S609, the base station 1 sends an LTM cell handover instruction to the terminal.

[0267] The LTM cell handover instruction indicates the target base station selected by the base station 1.

[0268] S610, the base station 1 sends the NCC processing indication information and the information of the candidate base stations to the target base station of the handover.

[0269] The NCC processing indication information sent in this step is the same as the NCC processing indication information sent to the terminal in S607, so that the processing of the NCC by the terminal and the target base station remains consistent. In FIG. 8a, the NCC processing indication information sent in this step indicates reservation as an example.

[0270] In this step, in addition to sending the NCC processing indication information, the base station 1 also sends the information of the candidate base stations, such as the identifiers of the candidate base stations. For example, the candidate base stations include the base station 2 and the base station 3, and the base station 1 also sends the identifier of the base station 3 to the base station 2.

[0271] S611, the terminal switches from the base station 1 to the base station 2 in response to the LTM cell handover instruction.

[0272] In FIG. 8a, the terminal uses the shared NCC=1 in this handover, for example. It is assumed that the terminal successfully switches from the base station 1 to the base station 2.

[0273] S612. The base station 2 sends the usage information of the NCC to the base station 3.

[0274] Because multiple base stations share the key, the target base station needs to share the usage of the NCC in this handover with other candidate base stations. In this step, the base station 2 as the target base station sends the usage information of the NCC to other base stations.

[0275] In some implementations, the usage information of the NCC is the NCC value used in this handover. In other implementations, the usage information of the NCC is the unused NCC value, including all unused NCC values in the shared NCC list. In yet another implementation, the usage information of the NCC is the NCC value used in the next handover.

[0276] It is also possible that the usage information of the NCC includes at least two of the above three, such as the unused NCC value and the NCC value used in the next handover.

[0277] Taking the NCC=1 used in this handover as an example, and assuming that the terminal successfully switches from the base station 1 to the base station 2, the unused NCC values in this handover are 2, 3, and the NCC value used in the next handover is 2. As shown in FIG. 8a, the base station 2 sends the usage information of the NCC to the base station 3, which is the NCC=1 used in this handover or the NCC=2 used in the next handover, or the unused NCC value.

[0278] It can be understood that the base station 2 sends the usage information of the NCC to the base station 3 based on the identifier of the base station 3 received previously.

[0279] S611. It can be understood that the handover process shown in S611 can also fail. The following describes the scenario of the handover failure, including the steps in the dashed box in FIG. 8a:

[0280] S613. The terminal fails to switch from the base station 1 to the base station 2.

[0281] S614. The terminal records the NCC value used in this handover and the information indicating the handover failure.

[0282] S615. The base station 2 sends the usage information of the NCC to the base station 3.

[0283] In case of handover failure, the usage information of NCC sent by the target base station to other candidate base stations is different from that in case of successful handover. In order to distinguish, the usage information of NCC sent in case of successful handover is referred to as first usage information of NCC, and the usage information of NCC sent in case of handover failure is referred to as second usage information of NCC.

[0284] In some implementations, the second usage information of NCC includes: the NCC value used in this handover and NCC processing indication information. Taking S615 in FIG. 8a as an example, the second usage information of NCC includes: NCC=1 used in this handover and reserved.

[0285] In this case, the base station 3 receiving the second usage information of NCC can determine that NCC=1 is used in next handover.

[0286] In other implementations, the second usage information of NCC includes: at least one of unused NCC value or next used NCC value.

[0287] After one handover failure, the terminal performs cell selection and initiates handover again, as follows:

[0288] S616, the terminal performs cell selection.

[0289] Here, it is assumed that the terminal selects the cell of the base station 3.

[0290] S617, the terminal performs handover from the base station 1 to the base station 3.

[0291] Based on the configuration of S615, NCC=1 is used in this handover. It is assumed that the handover in this step is successful, and S617 is performed.

[0292] S617, the base station 3 sends the first usage information of NCC to other base stations.

[0293] The first usage information of NCC sent in this step can be referred to S612, which is not described here again.

[0294] In FIG. 8a, taking the case that the NCC processing indication information indicates reserved as an example, the NCC processing indication information can also indicate discarded or reset value.

[0295] For the flow shown in FIG. 8a, an alternative mode is shown in FIG. 8b: in S607, the NCC processing indication information indicates discard, and in S610, base station 1 configures base station 2 with the NCC processing indication information indicating discard and the identity of base station 3. In the case of successful handover to base station 2 and the handover using NCC = 1, in S612, base station 2 sends base station 3 the NCC = 1 used this time, or the unused NCC value, or the NCC = 2 used next time. In the case of failed handover to base station 2 and the handover using NCC = 1, in S615, base station 2 sends base station 3 the NCC = 1 used this time and the NCC processing indication information indicating discard, or base station 2 sends base station 3 the unused NCC value, or the NCC = 2 used next time.

[0296] Another alternative mode is shown in FIG. 8c: in S607, the NCC processing indication information indicates a reset value such as NCC = 3, and in S610, base station 1 configures base station 2 with the processing indication information indicating the reset value and the identity of base station 3. In the case of successful handover to base station 2 and the handover using NCC = 1, in S612, base station 2 sends base station 3 the NCC = 1 used this time, or the unused NCC value, or the NCC = 2 used next time. In the case of failed handover to base station 2 and the handover using NCC = 1, in S615, base station 2 sends base station 3 the NCC = 1 used this time and the NCC processing indication information indicating the reset value, or base station 2 sends base station 3 the unused NCC value and the NCC processing indication information indicating the reset value, or the NCC = 3 (reset value) used next time.

[0297] In some cases, such as the NCC = 1 used this time to hand over to base station 2 and the reset value being NCC = 3, in this case, when hand over to base station 2 again, NCC = 3 is used, and NCC = 2 has not been used, in some implementations, such as using the NCC values in the NCC list in order, NCC = 2 is skipped and not used again. In other implementations, it is possible that NCC = 2 is used when hand over to base station 2 again later.

[0298] The flows shown in FIGS. 8a-8c share the NCC among the base stations, which can improve the utilization of the NCC. In the scenario of continuous multiple handovers of the LTM, the source base station configures the terminal with the NCC processing indication information to the target base station, and the target base station informs other candidate base stations of the use of the NCC, laying the foundation for the terminal and the base station to use matching keys in subsequent handovers.

[0299] Figure 9a is another method of processing a key provided by an embodiment of the present application, which is different from the flow shown in Figures 8a-8c in that the source base station informs the core network device of the information of the candidate base station, the target base station informs the core network device of the used NCC of this handover, and the core network device informs the candidate base station of the use information of the NCC.

[0300] Figure 9a includes the following steps:

[0301] S701. The AMF sends an NCC list to the base station 1.

[0302] S702. The terminal sends a measurement result to the base station 1.

[0303] S703. The base station 1 sends an LTM handover request message (i.e., a first handover request message) to the base station 2.

[0304] The specific implementation of this step can be seen in S603.

[0305] S704. The base station 2 sends an LTM handover request response (i.e., a first handover request response) to the base station 1.

[0306] The specific implementation of this step can be seen in S604.

[0307] S705. The base station 1 sends an LTM handover request message (i.e., a second handover request) to the base station 3.

[0308] S706. The base station 3 sends an LTM handover request response (i.e., a second handover request response) to the base station 1.

[0309] S707. The base station 1 sends an RRC reconfiguration message to the terminal.

[0310] The specific implementation of this step can be seen in S707.

[0311] S708. The terminal sends an RRC reconfiguration complete message to the base station 1.

[0312] S709. The base station 1 sends an LTM cell handover instruction to the terminal.

[0313] S710. The terminal switches from the base station 1 to the base station 2 in response to the LTM cell handover instruction.

[0314] In this step, the terminal uses a shared NCC = 1 as an example. It is assumed here that the terminal successfully switches from the base station 1 to the base station 2.

[0315] S711. The base station 1 sends information of the candidate base station to the AMF.

[0316] In this step, the information of the candidate base station takes the identification of the candidate base station as an example. In the case where there are multiple candidate base stations, a list of the identifications of the multiple candidate base stations is sent.

[0317] S712, the base station 2 sends the NCC value used in this handover to the AMF.

[0318] In FIG. 9a, the NCC=1 is used in this handover as an example.

[0319] S713, the AMF sends the NCC usage information to the base station 3.

[0320] In this step, because the NCC is managed by the AMF, the NCC usage information includes at least one of the unused NCC value and the NCC value used in next handover. The difference from FIG. 8a is that, in FIG. 8a, because the NCC is managed by the base station, the NCC usage information in S612 and S617 can also be the NCC value used in this time, but the NCC used in this time is not included in this step.

[0321] It can be understood that, in this embodiment, it is assumed that the candidate base stations are the base station 2 and the base station 3, because the base station 2 participates in this handover, the NCC used in this handover is known, therefore, the AMF does not need to send the NCC usage information to the base station 2 again, but not as a limitation, the AMF can also send the NCC usage information to the base station 2.

[0322] As shown in S713 in FIG. 9a, because the NCC=1 is used in this handover, the NCC=2 is used in next handover.

[0323] The following describes a case that the terminal-to-terminal handover from the base station 1 to the base station 2 fails.

[0324] S714, the terminal fails to handover from the base station 1 to the base station 2.

[0325] S715, the base station 1 sends the information of the candidate base station, the NCC value used in this handover and the NCC processing indication information to the AMF.

[0326] It can be understood that the NCC processing indication information sent to the AMF is the same as the NCC processing indication information configured to the terminal in S707, and the reservation is taken as an example in FIG. 9a.

[0327] S716, the AMF sends the NCC usage information to the base station 3.

[0328] In this step, the NCC usage information includes at least one of the unused NCC value and the NCC value used in next handover. The unused NCC value and the NCC value used in next handover are both decided by the AMF based on the NCC value used in this handover and the NCC processing indication information.

[0329] As the handover in S714 fails and the NCC processing indication information indicates reservation, the terminal still uses NCC=1 for the next handover.

[0330] S717: The terminal records the NCC value used in the current handover and information indicating that the handover fails.

[0331] S718: The terminal performs cell selection.

[0332] It is assumed here that the terminal selects the cell of base station 3.

[0333] S719: The terminal performs handover from base station 1 to base station 3.

[0334] Based on the NCC processing indication information indicating reservation, the terminal uses NCC=1 in the handover in this step, and based on the information sent in S716, base station 3 also uses NCC=1.

[0335] It is assumed here that the terminal successfully performs handover from base station 1 to base station 3, and the following steps are performed:

[0336] S720: Base station 3 sends the NCC value used in the current handover to the AMF.

[0337] As in the previous example, NCC=1 is used in the current handover.

[0338] S721: The AMF sends the NCC usage information to base station 2.

[0339] The NCC usage information in this step can be referred to in S713, which will not be repeated here.

[0340] It can be understood that the AMF sends the NCC usage information to the candidate base station, for example, base station 2, based on the information of the candidate base station received.

[0341] After the terminal successfully performs handover from base station 1 to base station 3, base station 1 can again send the information of the candidate base station to the AMF, or base station 1 can not send the information of the candidate base station to the AMF, as it is not the first time to perform handover from base station 1 to base station 3, which is not limited here.

[0342] The configuration process of the key information shown in FIG. 9a determines the use of NCC by the core network and sends the NCC usage information to each candidate base station. In addition to supporting the key requirements of continuous multiple handovers between base stations in the LTM scenario, there is no need for interaction between base stations, so the resources of the base stations can also be saved.

[0343] For FIG. 9a, an alternative implementation is shown in FIG. 9b: in S707, the NCC processing indication information in the RRC reconfiguration message sent by the base station 1 to the terminal indicates discard, in the case that the terminal successfully switches from the base station 1 to the base station 2, in S711, the base station 1 sends the identity of the candidate base station to the AMF, in S712, the base station 2 sends the NCC used in this switching to the AMF, in S713, the AMF sends the NCC value used in this switching (i.e. NCC = 1) to the base station 3, or the NCC used in the next switching is NCC = 2. In the case that the terminal fails to switch from the base station 1 to the base station 2, in S715, the base station 1 sends the identity of the candidate base station, the NCC used in this switching (i.e. NCC = 1) and the NCC processing indication information indicating discard to the AMF. In S716, the AMF sends the NCC value used in this switching to the base station 3, or the NCC used in the next switching is NCC = 2. It can be understood that, because the NCC processing indication information indicates discard, in the case of switching failure, the NCC used in the next switching is NCC = 2.

[0344] For FIG. 9a, another alternative implementation is shown in FIG. 9c: the NCC processing indication information configured by the base station 1 to the terminal in S707 indicates reset value, in the case of successful switching, the information exchanged between the source base station and the target base station and the AMF is as shown in FIG. 9a or FIG. 9b. In the case that the terminal fails to switch from the base station 1 to the base station 2, in S715, the base station 1 sends the identity of the candidate base station, the NCC used in this switching (i.e. NCC = 1) and the NCC processing indication information indicating reset value to the AMF. In S716, the AMF sends the NCC value used in this switching and the reset value to the base station 3, or the NCC used in the next switching is NCC = reset value.

[0345] It can be understood that, for FIG. 9a-FIG. 9c, an alternative implementation is that, in S711, the information of the candidate base station is sent by the terminal rather than the source base station to the AMF. Moreover, the NCC value used in this switching is no longer sent by the target base station to the AMF (i.e. S712 is not performed), but is sent by the terminal to the AMF. That is, the terminal sends the information of the candidate base station and the NCC value used in this switching to the AMF.

[0346] Specifically, in some implementations, if the current switching fails, the terminal sends the information of the candidate base station, the NCC value used in this switching and the NCC processing indication information to the AMF. In other implementations, if the current switching succeeds, the terminal sends the information of the candidate base station and the NCC value used in this switching to the AMF.

[0347] The AMF determines the NCC usage information based on the information sent by the terminal, and issues to each candidate base station. The specific steps can be referred to FIG. 9a-FIG. 9c, which will not be described here.

[0348] In some embodiments above, for the convenience of description, only the case of using the NCC value is described, but it can be understood that, in the case of involving using or selecting the NCC value without mentioning the first key, it actually means using or selecting the NCC value and the corresponding first key.

[0349] FIG. 10 is a structural example diagram of a terminal disclosed in an embodiment of the present application. Taking a mobile phone as an example, the terminal includes a processor 310, an external memory interface 320, an internal memory 321, a display screen 330, a camera 340, an antenna 1, an antenna 2, a mobile communication module 350, and a wireless communication module 360, and the like.

[0350] It can be understood that the structure illustrated in the embodiment does not constitute a specific limitation on the terminal. In some other embodiments, the terminal can include more or fewer components than those illustrated, or combine certain components, or split certain components, or different arrangement of components. The illustrated components can be implemented in hardware, software, or a combination of software and hardware.

[0351] The processor 310 can include one or more processing units. For example, the processor 310 can include an application processor (AP), a modem processor, a graphics processing unit (GPU), an image signal processor (ISP), a controller, a video codec, a digital signal processor (DSP), a baseband processor, and / or a neural-network processing unit (NPU), etc. Different processing units can be independent devices or integrated in one or more processors.

[0352] The external memory interface 320 can be used to connect an external memory card, such as a Micro SD card, to expand the storage capacity of the terminal. The external memory card communicates with the processor 310 through the external memory interface 320 to realize the data storage function. For example, files such as music and videos are saved in the external memory card.

[0353] The internal memory 321 can be used to store computer executable program codes, which include instructions. The processor 310 performs various functional applications and data processing of the terminal by executing the instructions stored in the internal memory 321. The internal memory 321 can include a program storage area and a data storage area. The program storage area can store an operating system, at least one application program required by a function (such as a sound playing function, an image playing function, etc.), and the like. The data storage area can store data created during the use of the terminal (such as audio data, a phone book, etc.), and the like. In addition, the internal memory 321 can include a high-speed random access memory, and can further include a non-volatile memory such as at least one magnetic disk storage device, a flash memory device, a universal flash storage (UFS), and the like. The processor 310 performs various functional applications and data processing of the terminal by executing the instructions stored in the internal memory 321 and / or the instructions stored in the memory disposed in the processor.

[0354] The wireless communication function of the terminal can be implemented by the antenna 1, the antenna 2, the mobile communication module 350, the wireless communication module 360, the modem processor, and the baseband processor, and the like.

[0355] The antenna 1 and the antenna 2 are used to transmit and receive electromagnetic wave signals. Each antenna in the terminal can be used to cover a single or multiple communication frequency bands. Different antennas can also be multiplexed to improve the utilization of the antennas. For example, the antenna 1 can be multiplexed as a diversity antenna of a wireless local area network. In some other embodiments, the antennas can be used in combination with a tuning switch.

[0356] The mobile communication module 350 can provide a solution including 2G / 3G / 4G / 5G wireless communication applied to the terminal. The mobile communication module 350 can include at least one filter, a switch, a power amplifier, a low noise amplifier (LNA), and the like. The mobile communication module 350 can receive electromagnetic waves by the antenna 1, and perform filtering, amplification, and the like on the received electromagnetic waves, and transmit the processed electromagnetic waves to the modem processor for demodulation. The mobile communication module 350 can also amplify the signals modulated by the modem processor, and convert the signals into electromagnetic waves to be radiated out through the antenna 1. In some embodiments, at least part of the functional modules of the mobile communication module 350 can be disposed in the processor 310. In some embodiments, at least part of the functional modules of the mobile communication module 350 and at least part of the modules of the processor 310 can be disposed in the same device.

[0357] In some embodiments, the terminal initiates or receives a call request through the mobile communication module 350 and the antenna 1.

[0358] In addition, on the above components, an operating system runs. For example, iOS operating system, Android operating system, Windows operating system, etc. Application programs can be installed and run on the operating system.

[0359] Fig. 11 is a structural example diagram of a base station 900 disclosed in an embodiment of the present application, including a 910 part, a 920 part, and a 930 part. The 910 part is mainly used for baseband processing, controlling the base station, etc. The 910 part is usually the control center of the base station, which can be usually referred to as a processor, for controlling the base station to perform the processing operations of the network device side in the above method embodiments. The 920 part is mainly used for storing computer program codes and data. The 930 part is mainly used for transceiving radio frequency signals and converting radio frequency signals and baseband signals. The 930 part can be usually referred to as a transceiving module, a transceiver, a transceiving circuit, or a transceiver, etc. The transceiving module of the 930 part can also be referred to as a transceiver or a transceiver, etc., which includes an antenna 933 and a radio frequency circuit (not shown in the figure), wherein the radio frequency circuit is mainly used for radio frequency processing. Optionally, the devices in the 930 part for realizing the receiving function can be regarded as a receiver, and the devices for realizing the sending function can be regarded as a transmitter, that is, the 930 part includes a receiver 932 and a transmitter 931. The receiver can also be referred to as a receiving module, a receiver, or a receiving circuit, etc., and the transmitter can be referred to as a transmitting module, a transmitter, or a transmitting circuit, etc.

[0360] The 910 part and the 920 part can include one or more single boards, and each single board can include one or more processors and one or more memories. The processors are used to read and execute the programs in the memories to realize the baseband processing functions and the control of the base station. If there are multiple single boards, the single boards can be interconnected to enhance the processing capability. As an optional implementation, the multiple single boards can also share one or more processors, or share one or more memories, or share one or more processors at the same time.

[0361] For example, in an implementation, the transceiving module of the 930 part is used to execute the transceiving-related processes performed by the base station in the above embodiments. The processor of the 910 part is used to execute the processing-related processes performed by the base station in the above embodiments.

[0362] It should be understood that Fig. 11 is only an example and not a limitation, and the above base station including the processor, the memory, and the transceiver can not depend on the structure shown in Fig. 11.

[0363] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto, and any change or replacement within the technical scope disclosed in the present application should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A method of processing a key, characterized by, The method applied to a terminal comprises: In response to a layer 1 or layer 2 triggered mobility LTM cell switching instruction, using a first key in a first switching process, the first key comprising a first NCC value, and a target base station of the first switching process being a first base station; If the first switching process fails, in a case of selecting the first base station as a target base station of a second switching process, using a second key in the second switching process, the second key comprising at least one acquired NCC value based on NCC processing indication information and the first NCC value, the NCC processing indication information being used to indicate a processing manner of the first NCC value.

2. The method of claim 1, wherein, The NCC processing indication information indicates to retain the first NCC value. The at least one acquired NCC value based on the NCC processing indication information and the first NCC value comprises: The first NCC value.

3. The method of claim 1, wherein, The NCC processing indication information indicates to discard the first NCC value. The at least one acquired NCC value based on the NCC processing indication information and the first NCC value comprises: A second NCC value, the second NCC value being different from the first NCC value.

4. The method of claim 1, wherein, The NCC processing indication information indicates a reset value, the reset value being a third NCC value; The at least one acquired NCC value based on the NCC processing indication information and the first NCC value comprises: The reset value.

5. The method according to any one of claims 1 to 4, characterized in that, Before performing the second switching process, further comprising: Recording the first NCC value and identification information of a target base station of the first switching process, and the second key being determined based on the first NCC value, the identification information and the NCC processing indication information.

6. The method according to any one of claims 1 to 5, characterized in that, Before receiving the LTM cell switching instruction, further comprising: Receiving key configuration information, the key configuration information comprising the NCC processing indication information.

7. The method of claim 6, wherein, The key configuration information further comprises: An NCC list corresponding to a candidate base station, the candidate base station comprising the first base station; The using the first NCC value in the first switching process comprises: Selecting the first NCC value not used in a switching process from an NCC list corresponding to the first base station for the first switching process.

8. The method according to any one of claims 1 to 7, characterized in that, Further comprising: In a case of selecting a second base station as a target base station of the second switching process, selecting a fourth NCC value not used in a switching process from an NCC list corresponding to the second base station for the second switching process, the second base station being different from the first base station.

9. The method according to any one of claims 1 to 8, characterized in that, Further comprising: After the first switching process, sending information of a candidate base station and NCC use information in the first switching process to a core network device, the NCC use information in the first switching process comprising the first NCC value and the NCC processing indication information.

10. The method according to any one of claims 1 to 9, characterized in that, Further comprising: If the first switching process succeeds, sending information of a candidate base station to a core network device.

11. A method of processing a key, characterized by, The method applied to a target base station of LTM switching comprises: In response to an LTM cell switching instruction, using a first key in a first switching process of a terminal switching to the target base station, the first key comprising a first NCC value; In a case that the first handover procedure fails, in a second handover procedure in which the terminal is handed over to the target base station, a second key is used, the second key comprising at least one obtained NCC value based on NCC processing indication information and the first NCC value, the NCC processing indication information being used to indicate a processing manner of the first NCC value.

12. The method of claim 11, wherein, The NCC processing indication information indicates to retain the first NCC value. The at least one obtained NCC value based on the NCC processing indication information and the first NCC value comprises: The first NCC value.

13. The method of claim 11, wherein, The NCC processing indication information indicates to discard the first NCC value. The at least one obtained NCC value based on the NCC processing indication information and the first NCC value comprises: A second NCC value different from the first NCC value.

14. The method of claim 11, wherein, The NCC processing indication information indicates a reset value, the reset value being a third NCC value. The at least one obtained NCC value based on the NCC processing indication information and the first NCC value comprises: The reset value.

15. The method according to any one of claims 11-14, characterized in that, Before the second handover procedure is performed, further comprising: Recording the first NCC value and identification information of a target base station of the first handover procedure, the second key being determined based on the first NCC value, the identification information and the NCC processing indication information.

16. The method according to any one of claims 11-15, characterized in that, Before the LTM cell handover instruction is received, further comprising: Configuring the NCC processing indication information to a source base station of LTM handover.

17. The method according to any one of claims 11-15, characterized in that, The LTM cell handover instruction carries the NCC processing indication information.

18. The method according to any one of claims 11-15, characterized in that, Further comprising: Sending, to a candidate base station of LTM, information of use of NCC in the first handover procedure.

19. The method of claim 18, wherein, The information of use of NCC in the first handover procedure comprises: Information of use of NCC in the first handover procedure, or an unused NCC value in pre-configured NCC values corresponding to the target base station, or an NCC value used in re-handover to the target base station.

20. The method of claim 19, wherein, In a case that the first handover procedure fails, the information of use of NCC in the first handover procedure comprises: an NCC value used in the first handover procedure and the NCC processing indication information; In a case that the first handover procedure succeeds, the information of use of NCC in the first handover procedure comprises: an NCC value used in the first handover procedure.

21. The method of claims 11-20, wherein, Further comprising: In a case that the first handover procedure succeeds, sending, to a core network device, the NCC value used in the first handover procedure.

22. A method of processing a key, the method comprising: Applied to a source base station of LTM handover, the method comprises: Configuring, to a terminal, key information corresponding to a candidate base station, the key information comprising NCC processing indication information; Sending, to the terminal, an LTM cell handover instruction, the LTM cell handover instruction instructing the terminal to initiate a first handover procedure of handover to a first base station, a first key being used in the first handover procedure, the first key comprising a first NCC value; The NCC processing indication information is used for indicating a processing manner of the first NCC value, and at least one of the NCC processing indication information and the first NCC value is used for obtaining a second key used in a second switching process in a case where a first switching process fails, the second key including a second NCC value, and the first switching process and the second switching process have a same target base station.

23. The method of claim 22, wherein, Before the terminal is configured with the NCC processing indication information, the method further includes: Receiving the NCC processing indication information sent by the target base station.

24. The method of claim 22, wherein, After the LTM cell switching instruction is sent to the terminal, the method further includes: Sending the NCC processing indication information to the target base station.

25. The method of claim 24, wherein, After the LTM cell switching instruction is sent to the terminal, the method further includes: Sending information of the candidate base station to the target base station.

26. The method of claim 22, wherein, After the LTM cell switching instruction is sent to the terminal, the method further includes: Sending information of the candidate base station to a core network device.

27. The method of claim 26, wherein, The first switching process fails; After the LTM cell switching instruction is sent to the terminal, the method further includes: Sending the NCC value used in the first switching process and the NCC processing indication information to the core network device.

28. The method of any one of claims 25-27, before the terminal is configured with the key information corresponding to the candidate base station, the method further includes: Receiving an NCC list sent by a core network device, the NCC list including NCC values shared by the candidate base station.

29. A method of processing a key, the method comprising: The method is applied to a core network device, and the method includes: Sending a plurality of NCC values to a source base station of an LTM; Receiving key configuration information, the key configuration information including information of a candidate base station of the LTM and information of use of NCC in a first LTM switching process; Sending at least one of an unused NCC value and a next used NCC value to the candidate base station, the unused NCC value being an NCC value unused in the first LTM switching process from the plurality of NCC values, and the next used NCC value being an NCC value used in a next LTM switching process of the first LTM switching process.

30. The method of claim 29, wherein, The first LTM switching process succeeds; The receiving of the key configuration information includes: Receiving an identifier of the candidate base station sent by a source base station of the first LTM switching process, and receiving an NCC value used in the first LTM switching process sent by a target base station of the first LTM switching process.

31. The method of claim 29, wherein, The first LTM switching process fails; The receiving of the key configuration information includes: Receiving the key configuration information sent by the source base station of the first LTM switching process, the key configuration information including the identifier of the candidate base station, the NCC value used in the first LTM switching process, and NCC processing indication information.

32. A terminal, characterized by The terminal includes one or more processors, a memory, and a touch screen; the memory is used for storing program code; and the processors are used for running the program code, so that the terminal implements the key processing method according to any one of claims 1 to 10.

33. A base station, comprising: comprising a processor and a memory for storing program code; the processor is configured to execute the program code, so that the base station implements the key processing method according to any one of claims 11 to 28.

34. A core network device, comprising: comprising a processor and a memory for storing program code; the processor is configured to execute the program code, so that the core network device implements the key processing method according to any one of claims 29 to 31.

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