Key processing method and related device

Abstract

The invention provides a secret key processing method and a related device, a terminal responds to a mobility LTM cell switching instruction triggered for layer 1 or layer 2, a first NCC value is used in a first switching process, a target base station of the first switching process is a first base station, the first switching process fails, and a second NCC value is used in a second switching process. In a case where the first base station is selected as a target base station for a second handover process, an NCC value acquired on the basis of at least one of the NCC processing instruction information and the first NCC value is used in the second handover process. The target base station of the first switching process and the target base station of the second switching process are the first base station, so that the terminal and the first base station need to have consistent understanding on the use of the NCC value under the condition that the first switching process is not successful, and the NCC value used in the second switching process is determined based on the NCC processing indication information and the first NCC value. Therefore, the terminal and the first base station can understand the use of the NCC value consistently, so that the matched key can be used to ensure the normal use of the key, and normal communication can be carried out.

Description

Technical Field

[0001] This application relates to the field of mobile communication technology, and in particular to a key processing method and related apparatus. Background Technology

[0002] In the field of mobile communications, terminals and networks use keys to communicate in order to ensure communication security. In some business processes, it is necessary to configure and process the keys used by the terminals and the network to ensure that the keys are used correctly and that normal communication is achieved. Summary of the Invention

[0003] This application provides a key processing method and related apparatus to achieve the purpose of processing keys during LTM handover. The disclosed technical solution is as follows:

[0004] The first aspect of this application provides a key processing method applied to a terminal. The method includes: in response to a mobility LTM cell handover command triggered by Layer 1 or Layer 2, using a first key in a first handover process. The first key includes a first NCC value. The target base station of the first handover process is a first base station. If the first handover process fails, and the first base station is selected as the target base station for a second handover process, using a second key in the second handover process. The second key is an NCC value obtained based on at least one of NCC processing indication information and the first NCC value. The NCC processing indication information indicates the processing method for the first NCC value. Because the target base station for both the first and second handover processes is the first base station, it is necessary for the terminal and the first base station to have a consistent understanding of the use of the NCC value in the event of a failed first handover. Determining the NCC value used in the second handover process based on the NCC processing indication information and the first NCC value facilitates a consistent understanding of the use of the NCC value between the terminal and the first base station, thereby using a matching key to ensure normal key usage and thus enabling normal communication.

[0005] In some implementations, the NCC processing instruction information indicates whether to retain the first NCC value, discard the first NCC value, or reset the value (i.e., the third NCC value). In practice, the NCC processing instruction information can be configured as needed to improve applicability and flexibility.

[0006] In some implementations, the NCC processing indication information indicates that a first NCC value should be retained. An NCC value obtained based on at least one of the NCC processing indication information and the first NCC value includes the first NCC value. Retaining the NCC value used during a failed handover, so that it can be used again when handing over to the first base station, facilitates full utilization of the NCC value.

[0007] In some implementations, the NCC processing indication information indicates that a first NCC value should be discarded. An NCC value obtained based on at least one of the NCC processing indication information and the first NCC value includes a second NCC value, which is different from the first NCC value. That is, the NCC value used during a failed handover is discarded, and the first NCC value is not used when handing over to the first base station again.

[0008] In some implementations, the NCC processing indication information indicates a reset value. The NCC value obtained based on the NCC processing indication information and at least one of the first NCC values ​​includes a reset value. The reset value is a third NCC value, which can be one of the NCC values ​​configured for the first base station, the first NCC value, or a value other than the first NCC value. The NCC processing indication information indicating a reset value allows for greater flexibility in the use of NCC values.

[0009] In some implementations, before executing the second handover procedure, the process includes recording the first NCC value and the identification information of the target base station of the first handover procedure. The second key is determined based on the first NCC value, the identification information, and the NCC processing instruction information. This is beneficial for the terminal to query the usage of NCC in the first handover procedure during subsequent handovers, thereby deciding on the NCC value to be used in subsequent handover procedures.

[0010] In some implementations, before receiving the LTM cell handover command, the process also includes receiving key configuration information, which includes NCC processing indication information. For example, the network can pre-configure the NCC processing indication information to the terminal, laying the foundation for consistent understanding of the NCC value between the terminal and the base station during LTM handover.

[0011] In some implementations, the key configuration information is carried in the RRC reconfiguration message.

[0012] In some implementations, the key configuration information also includes: a list of NCCs corresponding to candidate base stations, including the first base station. Different candidate base stations can correspond to different NCC lists, providing greater flexibility. Furthermore, the network can pre-configure the NCC list for the terminal, laying the foundation for consistent understanding and use of NCC values ​​by the terminal and base station during LTM handover.

[0013] In some implementations, the first NCC value is used in the first handover process, including: selecting a first NCC value that is not used in the handover process from the NCC list corresponding to the first base station for the first handover process, so as to ensure that the communication has higher security.

[0014] In some implementations, the method further includes: when selecting a second base station as the target base station for the second handover process, selecting a fourth NCC value not used in the handover process from the NCC list corresponding to the second base station for the second handover process. The second base station is different from the first base station. In other words, when the target base station of the second handover process is different from that of the first handover process, the NCC value used in the second handover process is selected from the NCC values ​​corresponding to the target base station (i.e., the second base station) of the second handover process. It can be seen that the NCC values ​​used by different base stations and the selection of NCC values ​​can be decoupled (independent of each other), which has higher flexibility and security.

[0015] In some implementations, the process further includes sending candidate base station information and NCC usage information from the first handover process to the core network equipment after the first handover procedure. This NCC usage information includes a first NCC value and NCC processing instruction information. Each candidate base station can share the NCC value. In this case, the terminal sending candidate base station information and NCC usage information from the first handover process to the core network equipment lays the foundation for the core network to distribute the NCC usage information from the first handover process to each candidate base station. This further lays the foundation for consistent understanding of the NCC value usage between each candidate base station and the terminal, which is beneficial for the terminal and the target base station to use matching keys during the LTM handover procedure.

[0016] Some implementations also include: if the first handover process is successful, sending candidate base station information to the core network equipment. Each candidate base station can share the NCC value. In this case, if the handover process is successful, sending candidate base station information to the core network equipment allows the core network equipment to synchronize the NCC usage information during the handover process with each candidate base station, which is beneficial for the terminal and the target base station to use matching keys during the LTM handover process.

[0017] A second aspect of this application provides a key processing method applied to a target base station during LTM cell handover. The method includes: in response to an LTM cell handover command, during a first handover process where a terminal hands over to the target base station, using a first key, the first key including a first NCC value; and in the event of a failure of the first handover process, during a second handover process where the terminal hands over to the target base station, using a second key, the second key including at least one NCC value obtained based on NCC processing indication information and the first NCC value, wherein the NCC processing indication information indicates the processing method for the first NCC value. Since the target base station for both the first and second handover processes is the first base station, it is necessary for the terminal and the first base station to have a consistent understanding of how to use NCC in the event of a failed first handover. Determining the NCC value used in the second handover process based on the NCC processing indication information and the first NCC value facilitates a consistent understanding of NCC usage between the terminal and the first base station, thereby enabling the use of a matching key to ensure normal key usage and thus normal communication.

[0018] In some implementations, the NCC processing instruction information indicates that a first NCC value should be retained; an NCC value obtained based on at least one of the NCC processing instruction information and the first NCC value includes: the first NCC value. Retaining the NCC value used in a failed switchover facilitates full utilization of the NCC value.

[0019] In some implementations, the NCC processing instruction information indicates that the first NCC value should be discarded; the NCC value obtained based on the NCC processing instruction information and the first NCC value includes: a second NCC value, which is different from the first NCC value.

[0020] In some implementations, the NCC processing instruction information indicates a reset value; an NCC value obtained based on at least one of the NCC processing instruction information and a first NCC value includes: a reset value, wherein the reset value is a third NCC value. Indicating a reset value using the NCC processing instruction information offers greater flexibility.

[0021] In some implementations, before executing the second handover procedure, the method further includes: recording the first NCC value and the identification information of the target base station of the first handover procedure. The second key is determined based on the first NCC value, the identification information, and the NCC processing instruction information. This is beneficial for the target base station of the first handover procedure to query the usage of NCC in the first handover procedure in subsequent handovers, thereby deciding on the NCC value to be used in subsequent handover procedures.

[0022] In some implementations, before receiving the LTM cell handover instruction, the process also includes configuring NCC processing indication information to the source base station of the LTM handover, thereby laying the foundation for the source base station to configure NCC processing indication information to the terminal. Furthermore, each candidate base station can configure its own NCC processing indication information, which provides greater flexibility.

[0023] In some implementations, the LTM cell handover command carries NCC processing indication information. That is, the source base station configures the NCC processing indication information to the target base station, laying the foundation for the target base station to select the same NCC value as the terminal.

[0024] In some implementations, this also includes sending NCC usage information from the first handover procedure to the candidate base stations of LTM. When all candidate base stations share the same NCC value, the target base station for LTM handover needs to send the NCC usage information from the first handover procedure to other candidate base stations so that other candidate base stations, when acting as the target base station for subsequent handovers, can use a key that matches the key used by the terminal.

[0025] In some implementations, the NCC usage information includes: NCC usage information during the first handover process, or unused NCC values ​​from the pre-configured NCC values ​​corresponding to the target base station, or NCC values ​​used during subsequent handovers to the target base station. NCC usage information helps candidate base stations use keys that match the keys used by the terminal during subsequent handovers.

[0026] In some implementations, if the first handover process fails, the NCC usage information in the first handover process includes: the NCC value used in the first handover process and the NCC processing instruction information, so that the target base station and the terminal can process the NCC value in a consistent manner. If the first handover process succeeds, the NCC usage information in the first handover process includes: the NCC value used in the first handover process. The NCC value used in the successful handover process is regarded as the used NCC value and will not be used again in the future, so there is no need to send the NCC processing instruction information again, which can save resources.

[0027] Some implementations also include: if the first handover process is successful, sending the NCC value used in the first handover process (i.e., the first NCC value) to the core network equipment. When all candidate base stations share the same NCC value, this allows the core network equipment to be informed of the NCC value used in the handover process, facilitating the core network equipment to synchronize the NCC value usage information with each candidate base station. This lays the foundation for each candidate base station to select the same NCC value as the terminal when acting as the target base station.

[0028] A third aspect of this application provides a key processing method applied to a source base station in an LTM handover. The method includes: configuring key information corresponding to a candidate base station to a terminal, the key information including NCC processing indication information; sending an LTM cell handover command to the terminal, the LTM cell handover command instructing the terminal to initiate a first handover process to a first base station; using a first key in the first handover process, the first key including a first NCC value; wherein at least one of the NCC processing indication information and the first NCC value is used to indicate the processing method for the first NCC value; in the event of a failure in the first handover process, the NCC processing indication information is used to obtain a second key used in a second handover process, the second key including a second NCC value; the first handover process and the second handover process have the same target base station. The NCC processing indication information configured by the source base station to the terminal lays the foundation for the terminal to select an NCC value in a second handover process to the same target base station after the first handover process fails, facilitating a consistent understanding of the use of the NCC value between the terminal and the target base station, thereby using a matching key to ensure normal key usage and communication.

[0029] In some implementations, before configuring the NCC processing instruction information to the terminal, the process includes receiving the NCC processing instruction information sent by the target base station. In other words, the source base station instructs the terminal on the NCC processing instruction information configured by the target base station, laying the foundation for the use of a matching key between the terminal and the target base station.

[0030] In some implementations, after sending the LTM cell handover command to the terminal, the process also includes sending NCC processing indication information to the target base station. That is, instead of each candidate base station configuring its own NCC processing indication information, the source base station configures the NCC processing indication information to the target base station, laying the foundation for the use of a matching key between the terminal and the target base station.

[0031] In some implementations, after sending the LTM cell handover command to the terminal, the method further includes sending information about the candidate base station to the target base station, so that the target base station can send information about the use of NCC in the handover process to the candidate base station.

[0032] In some implementations, after sending the LTM cell handover command to the terminal, the process also includes sending candidate base station information to the core network equipment. When all candidate base stations share the NCC value, this facilitates the core network equipment in sending NCC usage information during the handover process to each candidate base station.

[0033] In some implementations, the first handover process fails. After sending the LTM cell handover command to the terminal, the process also includes sending the first NCC value and NCC processing indication information to the core network equipment. When all candidate base stations share the NCC value, because the first handover process failed, the source base station, rather than the target base station, sends the NCC value and NCC processing indication information used in the first handover process to the core network equipment. This is beneficial for obtaining more accurate NCC values ​​and NCC processing indication information used in the first handover process.

[0034] In some implementations, before configuring the key information corresponding to the candidate base stations to the terminal, the process includes receiving an NCC list sent by the core network equipment. This NCC list includes NCC values ​​shared by the candidate base stations. In other words, the core network equipment sends the shared NCC values ​​of all candidate base stations to the source base station without requiring forwarding between the candidate base stations, resulting in higher communication efficiency.

[0035] A fourth aspect of this application provides a key processing method applied in a core network device. The method includes: sending multiple NCC values ​​to the source base station of an LTM (Local Time Management) system; receiving key configuration information, the key configuration information including: information about candidate base stations in the LTM system, and NCC usage information during a first LTM handover process; sending at least one of two NCC values—unused NCC values ​​or NCC values ​​to be used next—to the candidate base stations. The unused NCC values ​​are those unused in the first LTM handover process, and the next NCC value is the next LTM handover process after the first LTM handover process. Therefore, the core network device can configure shared NCC values ​​to candidate base stations and indicate at least one of two NCC values—unused NCC values ​​or NCC values ​​to be used next—laying the foundation for consistent understanding of NCC usage between the base station and the terminal during LTM handover.

[0036] In some implementations, upon successful completion of the first LTM handover process, key configuration information is received, including: receiving the identifier of the candidate base station sent by the source base station during the first LTM handover process, and receiving the NCC value used in the first LTM handover process sent by the target base station. It is evident that obtaining the NCC usage information from the source and target base stations lays the foundation for indicating at least one of two NCC values: either unused NCC values ​​or NCC values ​​to be used next by the candidate base station.

[0037] In some implementations, if the first LTM handover process fails, key configuration information is received, including: key configuration information sent by the source base station in the first LTM handover process. This key configuration information includes: the identifier of the candidate base station, the NCC value used in the first LTM handover process, and NCC processing instruction information. In the handover scenario, having the source base station send the key configuration information to the core network equipment is beneficial for obtaining more accurate key configuration information.

[0038] The fifth aspect of this application provides a terminal, which includes: 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 in the first aspect of this application.

[0039] The sixth aspect of this application provides a base station, including a processor and a memory, wherein the memory is used to store program code; and the processor is used to run the program code, causing the base station to implement the key processing method provided in the second or third aspect of this application.

[0040] The seventh aspect of this application provides a core network device, including a processor and a memory, wherein the memory is used to store program code; and the processor is used to run the program code, thereby enabling the core network device to implement the key processing method provided in the fourth aspect of this application.

[0041] The eighth aspect of this application provides a computer-readable storage medium having instructions stored thereon, which, when executed on an electronic device, cause the electronic device to perform a processing method for implementing the key provided in the first, second, third, or fourth aspect of this application.

[0042] The ninth aspect of this application provides a computer program product having stored thereon an executable method that, when run on an electronic device, causes the electronic device to implement the key processing method provided in the first, second, third, or fourth aspect of this application.

[0043] The tenth aspect of this application provides a chip system comprising: at least one processor and an interface, the interface being configured to receive code instructions and transmit them to the at least one processor; the at least one processor executing the code instructions to implement the key processing method provided in the first, second, third, or fourth aspect of this application. Attached Figure Description

[0044] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 This is a schematic diagram of the structure of a 5G network base station;

[0046] Figure 2 This is an example diagram of the keys required for communication between a terminal and a network;

[0047] Figure 3This is an example diagram illustrating the process of a terminal interacting with the network to obtain a key.

[0048] Figure 4 This is a flowchart illustrating the LTM process within a base station.

[0049] Figure 5 This is a flowchart illustrating the configuration of key information in the inter-base station LTM process provided in this application embodiment;

[0050] Figure 6a This is a flowchart of a key processing method provided in an embodiment of this application;

[0051] Figure 6b This is a flowchart of another key processing method provided in the embodiments of this application;

[0052] Figure 6c This is a flowchart of another key processing method provided in the embodiments of this application;

[0053] Figure 6d This is a flowchart of another key processing method provided in the embodiments of this application;

[0054] Figure 7 This is a flowchart of another key processing method provided in the embodiments of this application;

[0055] Figure 8a This is a flowchart of another key processing method provided in the embodiments of this application;

[0056] Figure 8b This is a flowchart of another key processing method provided in the embodiments of this application;

[0057] Figure 8c This is a flowchart of another key processing method provided in the embodiments of this application;

[0058] Figure 9a This is a flowchart of another key processing method provided in the embodiments of this application;

[0059] Figure 9b This is a flowchart of another key processing method provided in the embodiments of this application;

[0060] Figure 9c This is a flowchart of another key processing method provided in the embodiments of this application;

[0061] Figure 10 This is a structural example diagram of a terminal disclosed in an embodiment of this application;

[0062] Figure 11 This is a structural example diagram of a base station disclosed in an embodiment of this application. Detailed Implementation

[0063] The terms "first," "second," and "third," etc., used in this application specification, claims, and drawings are used to distinguish different objects, not to limit a specific order.

[0064] In the embodiments of this application, the words "in some implementations" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0065] The technical solutions provided in the embodiments of this application are applied to mobile communication systems, which include terminals and networks, and the networks include access network equipment and core network equipment.

[0066] Mobile communication systems include, but are not limited to: Long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD) systems, Universal Mobile Telecommunications System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) systems, UMTS Terrestrial Radio Access Network (UTRAN) systems, or GSM EDGE Radio Access Network (GERAN) systems of Global System for Mobile Communication (GSM) / Enhanced Data Rate for GSM Evolution (EDGE) systems. Furthermore, the technical solutions provided in this application can also be applied to any other wireless communication system with similar structure and function, such as Public Land Mobile Network (PLMN) system, 5th Generation (5G) communication system, communication systems after 5G, New Radio Access Technology (NR) system, Vehicle-to-X (V2X) system, etc.The V2X system may include vehicle-to-network (V2N) systems, vehicle-to-vehicle (V2V) systems, vehicle-to-infrastructure (V2I) systems, vehicle-to-pedestrian (V2P) systems, Long Term Evolution-Vehicle (LTE-V) systems, vehicle-to-everything (V2X) systems, machine-type communication (MTC) systems, Internet of Things (IoT) systems, Long Term Evolution-Machine (LTE-M) systems, and machine-to-machine (M2M) systems, etc., and this application does not impose any limitations on these embodiments.

[0067] Access network equipment can be, but is not limited to, devices with wireless transceiver capabilities. Specifically, it can include, but is not limited to: evolved Node Bs (NodeBs, eNBs, or e-NodeBs) in LTE, base stations (gNodeBs or gNBs) or transmission receiving points / transmission reception points (TRPs) in NR, radio access network (RAN) equipment, base stations evolved from 3GPP, access nodes, wireless relay nodes, and wireless backhaul nodes in WiFi systems. Access network equipment can also be radio controllers, centralized units (CUs), and / or distributed units (DUs) in cloud radio access network (CRAN) scenarios. Network equipment can also be servers, wearable devices, or vehicle-mounted equipment, etc.

[0068] The base station can be a macro base station, micro base station, pico base station, small cell, relay station, or balloon station, etc. Multiple base stations can support networks using the same technology mentioned above, or they can support networks using different technologies mentioned above. A base station can contain one or more co-located or non-co-located TRPs.

[0069] like Figure 1As shown, a 5G network base station consists of two parts: a centralized unit (CU) and a distributed unit (DU). The CU and DU are separated 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, while the CU is responsible for the Packet Data Convergence Protocol (PDCP) layer and the Radio Resource Control (RRC) layer.

[0070] When there are multiple access network devices, these devices can be of the same type or different types. Access network devices can communicate directly with terminal devices or via relay stations. Terminal devices can communicate with multiple access network devices using different technologies; for example, a terminal device can communicate with a base station supporting LTE networks, or with a base station supporting 5G networks, and can also support dual connectivity with both LTE and 5G base stations.

[0071] Terminals can include handheld devices or vehicle-mounted devices with wireless transceiver capabilities, specifically including but not limited to: mobile phones, tablets, PDAs, laptop computers, laptops, computers with wireless transceiver capabilities, mobile internet devices (MIDs), wearable devices, virtual reality (VR) devices, augmented reality (AR) devices, wireless terminals in industrial control, vehicle-mounted terminal equipment, wireless terminals in self-driving vehicles, wireless terminals in remote medical surgery, wireless terminals in smart grids, wireless terminals in transportation safety, wireless terminals in smart cities, wireless terminals in smart homes, cellular phones, cordless phones, session initiation protocol (SIP) phones, wireless local loop (WLL) stations, and personal digital assistants (PDAs). The embodiments of this application do not limit this to personal assistants (PDAs), handheld devices with wireless communication capabilities, computing devices or other processing devices connected to a wireless modem, in-vehicle devices, wearable devices, terminal devices in 5G networks or terminal devices in future evolved public land mobile networks (PLMNs).

[0072] By way of example and not limitation, in this embodiment, the terminal can also be a wearable device. Wearable devices, also known as wearable smart devices, are a general term for devices that utilize wearable technology to intelligently design and develop everyday wearables, such as glasses, gloves, watches, clothing, and shoes. Wearable devices are portable devices that are worn directly on the body or integrated into the user's clothing or accessories. Wearable devices are not merely hardware devices, but also achieve powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include those that are feature-rich, large in size, and can achieve complete or partial functions without relying on a smartphone, such as smartwatches, smart helmets, or smart glasses, as well as those that focus on a specific type of application function and require the use of other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring.

[0073] Furthermore, in this embodiment, the terminal can also be a terminal device in an Internet of Things (IoT) system. IoT is an important component of the future development of information technology. Its main technical feature is to connect objects to the network through communication technology, thereby realizing an intelligent network of human-machine interconnection and object-to-object interconnection.

[0074] The terminal equipment in this application embodiment may also be referred to as: electronic equipment, user equipment (UE), mobile station (MS), subscriber unit (SU), mobile terminal (MT), access terminal, access terminal equipment, vehicle-mounted terminal, industrial control terminal, UE unit, UE station, user unit, user station, mobile station, mobile station, remote station, remote terminal, remote terminal equipment, mobile device, user terminal, UE terminal equipment, terminal, wireless communication equipment, user agent, UE agent, UE device, or user equipment, etc.

[0075] The technical solutions provided in the embodiments of this application aim to configure the keys used in Layer 1 / 2 triggered mobility (LTM) processes. To better illustrate the technical solutions provided in the embodiments of this application, the relevant content of keys and LTM will be explained first.

[0076] Figure 2 These are examples of the various keys used for communication between a terminal and a network, as well as examples of the relationships between these keys. Figure 2 In the middle, K SEAF The anchor key is obtained jointly by the terminal, the network element using the Security Anchor Function, and the terminal itself. AMF Indicated based on K SEAF The key is obtained through the participation of the Access and Mobility Management Function (AMF) network element and the terminal. RRC-enc K represents the encryption key for Radio Resource Control (RRC) signaling. RRC-int This represents the RRC signaling integrity protection key. K UP-enc K represents the encryption key for the data plane (UP) data. UP-int This represents the integrity protection key for UP data. NH represents the next-hop parameter, and NCC represents the link counter in NH.

[0077] In this embodiment, K gNB*Called the first key, K gNB It is called the second key.

[0078] Figure 2 The keys shown are some commonly used keys for communication between terminals and base stations. They are only examples and do not represent all keys in the field of mobile communication. Arrows can indicate the deductive relationships between keys; for example, the first key K... gNB* Obtained from NCC, second key K gNB Based on the first key K gNB* and K AMF Get. From Figure 2 It can be seen that, based on K SEAF Through step-by-step deduction, other keys can be obtained.

[0079] Figure 2 In the example of the first and second keys in a 4G communication system, in a 5G communication system, the first key is represented as K. NG-RAN* The second key is represented as K NG-RAN In the following embodiments, K is used as... gNB* and K gNB For example, it is understandable that K gNB* Can be replaced with K NG-RAN* K gNB Can be replaced with K NG-RAN .

[0080] Figure 3 An example of a process for an end to interact with a network to obtain a key includes the following steps:

[0081] S101. During the security authentication process with the network, the terminal obtains K... SEAF And further deduced to obtain K AMF .

[0082] The following will execute the security context establishment process:

[0083] S102. The base station obtains the terminal's security capability information from the AMF.

[0084] S103. The base station determines the terminal's security algorithm based on the terminal's security capability information.

[0085] S104, Terminal and AMF Execution Derivation K gNB The process of NH.

[0086] S105, K is derived from the base station. gNB Encryption keys and integrity protection keys.

[0087] It is understandable that S104 obtained K gNB K obtained with S105gNB same.

[0088] The signaling encryption key includes the encryption key for RRC signaling and the encryption key for UP data. The integrity protection key includes the integrity protection key for RRC signaling and the integrity protection key for UP data.

[0089] The key obtained in S105 is used for subsequent communication between the terminal and the base station.

[0090] LTM is a mobility enhancement technology. Figure 4 This is an example of the LTM process.

[0091] Figure 4 In this context, the source cell is the cell where the terminal was located before the handover, and the target cell is the cell where the terminal will be located after the handover. The target cell is selected from the candidate cells. Figure 4 Taking candidate cell 1 as the target cell as an example, for information on target cell selection, please refer to [link / reference]. Figure 4 S210 in the middle. Figure 4 The example uses two candidate cells, but does not limit the number of candidate cells.

[0092] Because it's a switch within the CU, Figure 4 The source cell and candidate cell shown belong to the same CU. Figure 4 The terminal is already in a connected state.

[0093] Figure 4 The process includes the following steps:

[0094] S201. The terminal sends the measurement results to the source cell.

[0095] A terminal in connected state is currently connected to the source cell. The measurement results indicate the terminal's measurement results for each candidate cell. Specifically, layer (L) measurement reporting can be performed based on the configured candidate cells. This layer measurement reporting can include any type of layer measurement reporting, such as layer 1, layer 2, or layer 3. Candidate cells can refer to all neighboring cells that the terminal can access.

[0096] The source cell determines the terminal's support capability for LTM based on the measurement results, and determines to execute LTM based on the terminal's support capability for LTM, and executes the candidate cell configuration preparation process, including S202-S205.

[0097] S202, the source cell sends an LTM handover request message to candidate cell 1.

[0098] S203, Candidate Cell 1 sends an LTM handover request response message to the source cell.

[0099] The LTM handover request response message sent by candidate cell 1 includes the configuration information of candidate cell 1.

[0100] S204. The source cell sends an LTM handover request message to candidate cell 2.

[0101] S205, Candidate Cell 2 sends an LTM handover request response message to the source cell.

[0102] The LTM handover request response message sent by candidate cell 2 includes the configuration information of candidate cell 2.

[0103] S206. The source cell sends an RRC reconfiguration message to the terminal.

[0104] The RRC reconfiguration message includes the configuration information for subsequent cell 1 and the configuration information for candidate cell 2.

[0105] S207. The terminal sends an RRC reconfiguration complete message to the source cell.

[0106] The RRC reconfiguration complete message indicates that the terminal has received the RRC reconfiguration message.

[0107] S208. The terminal executes the downlink synchronization process for the candidate cell.

[0108] S209. The terminal executes the uplink synchronization process for the candidate cell.

[0109] In some implementations, the RRC reconfiguration information indicates that the terminal measures the uplink timing advance, the terminal measures the timing advance of the source cell, and determines the timing advance of the target cell based on the reception time difference between the source cell and the target cell.

[0110] In other implementations, the source cell triggers Contention-Free Random Access (CFRA) via a Physical Downlink Control Channel (PDCCH) order to obtain the timing advance of candidate cells. The terminal initiates CFRA to the candidate cells to obtain the timing advance, and the network manages the validity of the timing advance.

[0111] S210, The terminal sends an L1 measurement reporting message to the source cell.

[0112] The terminal performs measurements on the L1 layer of the source cell and the L1 layer of the candidate cell respectively, and obtains the L1 measurement results. The L1 measurement reporting message includes the L1 measurement results.

[0113] S211, The source cell sends an LTM handover command to the terminal.

[0114] The source cell selects the target cell from the candidate cells based on the L1 measurement and reporting message, and the handover command instructs the terminal to hand over from the source cell to the target cell.

[0115] In some implementations, the handover command includes a MAC control element (CE). The MAC CE includes at least the following information: timing advance, transmission configuration indication (TCI) state id, CFRA resource information, and candidate cell configuration information identifier.

[0116] Among them, the timing advance is the timing advance that the terminal obtains and is still in a valid state. That is, before S211, if the network determines that the TA obtained by the terminal before is still in a valid state, then the TA is included in the MAC CE.

[0117] S212, The terminal disconnects from the source cell.

[0118] S213. The terminal and the target cell execute a random access procedure.

[0119] In an alternative to S213, when the terminal receives a handover MAC CE, if the MAC CE has a TA value, or if the terminal tests the TA itself, the terminal will initiate a handover to the target cell without random access. That is, the terminal only needs to send one uplink signaling or the first uplink data packet to the target cell to indicate that it has completed access to the target cell.

[0120] S214. The terminal completes LTM handover between the terminal and the target cell.

[0121] Figure 4 The LTM procedure shown supports switching within the CU.

[0122] Understandably, in execution Figure 4 Before the handover process shown, the terminal and the network have already completed the necessary communication. Figure 2 This example demonstrates key negotiation and retrieval. Because it involves a switch within the CU, therefore... Figure 4 The source cell, target cell, and candidate cell shown belong to the same CU, therefore Figure 4 The LTM procedure shown does not involve key updates during cell handover.

[0123] Research has found that, in order to expand the application scope of LTM, supporting handover between different base stations is a growing trend. Handover between different base stations necessitates consideration of key issues.

[0124] The study also found that further improvements can be made to enhance LTM performance. One feasible improvement is to enable the terminal to perform multiple consecutive LTM handovers after configuring LTM candidate cells once. For example, after the terminal hands over from the source base station to the first base station, it does not need to configure candidate cells and can hand over to the second base station. This includes continuing to hand over to the second base station if the handover from the source base station to the first base station fails.

[0125] To achieve multiple consecutive LTM handovers, LTM technology still faces at least the following unresolved issues: how to configure and update key information. These issues include the following specific aspects:

[0126] 1. Multiple LTM handovers involve the terminal connecting to different base stations, and may also involve multiple connections to the same base station. To ensure communication security, the terminal needs to use a key to communicate with the base station. Therefore, how to configure different keys for multiple connections to the base station during multiple handovers is a problem that needs to be solved.

[0127] To solve problem 1, in some implementation methods, such as Figure 5 As shown, the key information configuration process includes the following steps:

[0128] S301, The terminal sends the measurement results to base station 1.

[0129] The terminal in the connected state is currently connected to base station 1 and reports the measurement results of each candidate cell to base station 1.

[0130] Base station 1 acts as the source base station. It determines the terminal's support capability for LTM based on measurements, and determines to execute LTM based on the terminal's support capability for LTM. It also executes the candidate cell configuration preparation process, including S302-S305.

[0131] S302, Base station 1 sends an LTM handover request to base station 2.

[0132] To support the key requirements of multiple connections with base station 2 that may occur during multiple handovers, this step includes a key list configured for base station 2 in the LTM handover request. The key list contains multiple sets of keys configured for base station 2. Each set of keys includes a corresponding first key K. gNB* The first key value and the NCC value. The corresponding first key value and NCC value can be understood as follows: the first key value is generated from the NCC value, that is, the first key value corresponds to the NCC value. The terminal can be based on... Figure 2 Using the deductive relationship as an example, obtain the first key K. gNB* The specific procedures for determining the NCC value and NCC value are beyond the scope of this application and will not be elaborated here.

[0133] For ease of explanation, the LTM handover request sent to base station 2 in this step will be referred to as the first handover request, and the key list in the first handover request will be referred to as the first key list. Figure 5 The middle is represented as (K) gNB* ,NCC)list1.

[0134] S303, Base Station 2 sends an LTM handover request response to Base Station 1.

[0135] The LTM handover request response includes an NCC list. The NCC list includes the NCC values ​​from multiple sets of keys configured for base station 2.

[0136] The LTM handover request response sent by base station 2 is referred to as the first handover request response, and the NCC list in the first handover request response is referred to as the first NCC list. Figure 5 The Chinese text is represented as NCC list1.

[0137] S304, Base Station 1 sends an LTM handover request to Base Station 3.

[0138] To support the key requirements of multiple connections with base station 3 that may occur during multiple handovers, the LTM handover request in this step includes a key list configured for base station 3. This key list contains multiple sets of keys configured for base station 3. Each set of keys includes a corresponding first key K. gNB* Value and NCC value.

[0139] The LTM handover request sent to base station 3 is called the second handover request, and the key list in the second handover request is called the second key list. Figure 5 The middle is represented as (K) gNB* ,NCC)list2.

[0140] The first key list and the second key list can be the same or different. In other words, the key lists sent by the source base station to each candidate base station can be the same or different.

[0141] S305, Base Station 3 sends an LTM handover request response to Base Station 1.

[0142] The LTM switchover request response includes a list of NCCs.

[0143] The LTM handover request response sent by base station 3 is referred to as the second handover request response, and the NCC list in the second handover request response is referred to as the second NCC list. Figure 5 This is represented as NCC list2. The second NCC list includes the NCC values ​​from multiple sets of keys configured for base station 3.

[0144] S306, Base Station 1 sends an RRC reconfiguration message to the terminal.

[0145] The RRC reconfiguration message includes: a first key list, the identifier of base station 2 corresponding to the first key list, a second key list, and the identifier of base station 3 corresponding to the second key list.

[0146] Understandably, because the terminal may select the cell of base station 1 when choosing the target cell for handover (i.e., base station 1 is also the target base station), the RRC reconfiguration message also includes: the key list used by base station 1 (i.e., the third key list), and the identifier of base station 1 corresponding to the third key list. Figure 5 (Not shown in the drawing).

[0147] The purpose of the base station identifier corresponding to the key list is to help the terminal distinguish the key lists configured by different base stations, so that when switching to a target base station in the future, the terminal can select the key from the key list corresponding to that target base station.

[0148] S307. The terminal sends an RRC reconfiguration complete message to base station 1.

[0149] The RRC reconfiguration complete message indicates that the terminal has received the RRC reconfiguration message.

[0150] from Figure 5 As can be seen from the process shown, the source base station configures multiple sets of keys for the candidate base station and the terminal respectively to support the encryption requirements of multiple connections with the base station during multiple LTM handovers.

[0151] Further research found that: even based on Figure 5 The process shown also has some problems:

[0152] 2. Continuous handover is intended to improve the handover performance of LTM, such as increasing handover efficiency. However, if the network needs to configure key information to the terminal before each handover (e.g., ...), ... Figure 5 As shown in S306 and S307, the improvement in handover efficiency is limited, and there is also a significant signaling overhead. Therefore, how to support multiple consecutive handovers by configuring key information to the terminal only once is a problem that needs to be solved.

[0153] 3. Based on the technical approach of configuring key information to the terminal once to support multiple consecutive switching, how to ensure that the terminal and the network have a consistent understanding of the key during multiple consecutive switching processes, so that the terminal and the network can use matching keys to communicate and ensure normal communication, is a problem that needs to be solved.

[0154] To address the aforementioned technical problems 2 and 3, embodiments of this application provide a key processing method, such as... Figure 6a As shown, assume that the terminal is currently connected to base station 1, that is, base station 1 is the source base station, and base stations 2 and 3 are candidate base stations.

[0155] Figure 6a The process includes the following steps:

[0156] S401, The terminal sends the measurement results to base station 1.

[0157] S402, Base station 1 sends an LTM handover request message (i.e., the first handover request message) to base station 2.

[0158] The first handover request message includes: a first key list configured for base station 2, as detailed in S302.

[0159] S403, Base station 2 sends an LTM handover request response (i.e., the first handover request response) to base station 1.

[0160] and Figure 5 In contrast, the first switch request response includes a first NCC list and NCC processing instructions.

[0161] To enhance security, each successful handover to a base station uses a set of keys to communicate with that base station. Subsequent handovers to the same base station require a new key. Therefore, if a handover to a base station is successful, the key used is considered a used key and will not be reused. However, it's understandable that if a handover to a base station fails, the key used in that handover cannot be considered a fully used key. Therefore, the terminal and the base station need to establish a consistent handling method for keys used in failed handovers so that the terminal and base station can use a matching key the next time they handover to that base station.

[0162] NCC processing indication information is used to indicate how to handle NCC values. In the context of LTM (Low-Time Management), this information specifies how to handle the NCC value after a failed handover to a target base station during the LTM handover process. NCC processing indication information is one type of pre-configured processing indication information. These pre-configured indications specify: retain, discard, and reset the value. Figure 6a In this example, we take the NCC's instruction to retain information as an example.

[0163] Retention can be understood as: retaining the NCC value used in a failed switch as an unused NCC value, instead of using it as a used NCC value, so that it can be used again later.

[0164] Assuming the target base station of the failed handover is the first base station, and the failed handover uses the first NCC value, the reserved statement indicates that the first NCC value will still be used for subsequent handovers to the first base station.

[0165] Discarding can be understood as: taking the NCC value used in the failed switch as the already used NCC value, and not using it again in the future.

[0166] Assuming the target base station of the failed handover is the first base station, and the failed handover used the first NCC value, discarding means that subsequent handovers to the first base station will no longer use the first NCC value, but will use a second NCC value, which is 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.

[0167] The reset value can be understood as a specified NCC value, and subsequent switches will start using this specified NCC value.

[0168] Assuming the target base station of the failed handover is the first base station, and the failed handover used the first NCC value, the reset value means that subsequent handovers to the first base station will no longer use the first NCC value, but will use the reset value. This can be understood as the NCC value in the NCC list sent by the first base station to the source base station (i.e., base station 1).

[0169] In some implementations, the NCC processes the instruction information as characters or numbers, or a combination of characters and numbers.

[0170] It is understood that "NCC processing instruction information" is merely an example and may also be referred to as "NCC instruction information," "NCC instruction message," etc., without limitation. Regardless of the name used, the function is the same as the method for switching the NCC value when the instruction fails.

[0171] S404, Base station 1 sends an LTM handover request message (i.e., the second handover request) to base station 3.

[0172] S405, Base station 3 sends an LTM handover request response (i.e., the second handover request response) to base station 1.

[0173] The second switch request response includes a second NCC list and NCC processing instructions.

[0174] It is understandable that the NCC processing instruction information sent by base station 2 and the NCC processing instruction information sent by base station 3 may be the same or different. Figure 6a In this example, the NCC processing indication information sent by base station 3 also takes the indication retention as an example.

[0175] S406, Base Station 1 sends an RRC reconfiguration message to the terminal.

[0176] The RRC reconfiguration message includes: a key list for each candidate base station (base station 2 and base station 3, and possibly base station 1) and the corresponding base station identifier, as detailed in S306.

[0177] In this step, the RRC reconfiguration message also includes: NCC processing indication information for each base station.

[0178] 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). If the NCC processing indication information configured by base station 2 in S403 is retained, then 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 is also retained.

[0179] Figure 6a In this example, if all candidate base stations indicate "reservation" in their NCC processing indication information, then it is not necessary for each candidate base station's identifier to correspond to a "reservation". It is understandable that, when candidate base stations correspond to different NCC processing indication information, the RRC reconfiguration message indicates the correspondence between the identifiers of each candidate base station and the NCC processing indication information.

[0180] S407. The terminal sends an RRC reconfiguration complete message to base station 1.

[0181] S408, Base Station 1 sends an LTM cell handover command to the terminal.

[0182] In this embodiment, it is assumed that base station 1 selects base station 2 as the target base station, and the LTM cell handover instruction instructs the terminal to switch from base station 1 to base station 2.

[0183] S409, Base Station 1 sends an LTM cell handover command to Base Station 2.

[0184] LTM cell handover commands are used to instruct the target base station to begin handover.

[0185] S410, the terminal responds to the LTM cell handover command and initiates the process of handing over from base station 1 to base station 2.

[0186] Understandably, if a handover to base station 2 is initiated for the first time, it is considered an initial handover to base station 2. There are no recorded NCC values ​​or handover results for handovers to base station 2; in other words, the historical records are empty. Therefore, the NCC value for this handover is selected from the first NCC list configured for the terminal by base station 2. In some implementations, NCC values ​​are selected sequentially in ascending order from the smallest to the largest NCC value in the NCC list.

[0187] In this embodiment, it is assumed that during this handover process, the terminal selects NCC=1 and the K corresponding to NCC=1 from the first NCC list corresponding to the identifier of base station 2. gNB* And assuming the switchover fails, Figure 6a In the text, "×" indicates that the switching failed.

[0188] In this embodiment, a handover failure can be due to either failure to handover to the target cell or a radio link failure (RLF) occurring within a short period of time after handover to the target cell. The determination of failure to handover to the target cell is as follows: after the terminal receives the LTM cell handover instruction, it starts a timer. If the timer's recorded duration exceeds a threshold, the handover to the target cell has not been successfully completed.

[0189] S411. The terminal records the NCC value used in this handover, as well as information indicating that the handover failed.

[0190] Continuing from the previous example, the terminal records that NCC=1 was used for this handover, as well as information indicating that the handover failed.

[0191] In some implementations, the information indicating a handover failure is the identification information of the target base station of the failed handover. In the example of this embodiment, the information indicating a handover failure is the identification information of base station 2.

[0192] In some other implementations, the information indicating a handover failure may include not only the identifier of the target base station of the failed handover, but also other information, such as the timestamp of the failed handover, or the information of the target cell under the target base station of the failed handover, etc., which are not limited here.

[0193] S412, Terminal selects cell.

[0194] After a handover failure, the terminal needs to select a new connectable cell. The selection of a cell can be based on factors such as the cell's quality parameters, which will not be elaborated here.

[0195] It is understandable that the cell selected by the terminal in this step may be the cell of base station 2, or it may be the cell of base station 3 or base station 1.

[0196] In this embodiment, it is assumed that the cell selected in this step belongs to base station 2.

[0197] S413a, The terminal initiates the handover process to base station 2.

[0198] The terminal selects the NCC value to be used in this handover from the list of stored NCCs by querying the recorded content and the stored NCC processing instruction information.

[0199] Because S411 has already recorded NCC=1, and the corresponding handover result is handover failure, the NCC processing indication information is retained. Therefore, the terminal still selects NCC=1 from the first NCC list corresponding to the identifier of base station 2, and the K corresponding to NCC=1. gNB* .

[0200] Understandably, base station 2 makes the same selection as the terminal. Assuming this handover is successful, both the terminal and base station 2 will use NCC=1 and the corresponding K. gNB* The encryption key and integrity protection key are derived to enable normal communication.

[0201] from Figure 6a As can be seen from the process shown, through the RRC reconfiguration message, the source base station sends the key information configured by each candidate base station and the NCC processing instruction information to the terminal, so that the terminal can have the same key selection rules with the target base station in multiple consecutive handover processes. This ensures that the terminal and the base station use matching keys to communicate, and there is no need to configure the key before each handover, so it can also save signaling overhead.

[0202] Figure 6a Taking the NCC's processing of instruction information and instruction retention as an example, an alternative method is to use... Figure 6b For example: If the NCC processing indication information indicates that the data should be discarded, then during the handover in S413a, the terminal selects NCC=2 and the corresponding K from the first NCC list corresponding to the identifier of base station 2. gNB* It's understandable that "discarding" means no longer using NCC=1. Here, we'll use NCC=2 as an example, but this isn't a limitation; other unused NCC values ​​from the first NCC list can also be selected. Base station 2 also selects NCC=3, and the corresponding K... gNB* .

[0203] Another alternative is to Figure 6c For example: The NCC processing indication information indicates a reset value. Assuming the reset value is 5, in S413a, the terminal selects NCC=5 and the K corresponding to NCC=5 from the first NCC list corresponding to the identifier of base station 2. gNB* Base station 2 also selects NCC=5, and the corresponding K for NCC=5. gNB* .

[0204] It should be noted that in the accompanying drawings of the embodiments of this application, the NCC value is used as an example, and the first key corresponding to the NCC is not shown. However, it can be understood that in practice, the NCC value and the corresponding first key are used.

[0205] Figure 6d Another key processing method provided for embodiments of this application, and Figures 6a-6cThe difference lies in the following: After the terminal fails to hand over to base station 2, in S412, the terminal selects the cell of base station 3. In this case, in S413b, the terminal initiates a handover to base station 3. Assuming this is the first time the terminal initiates a handover to base station 3, and the pre-configuration uses the NCC values ​​in the second NCC list in ascending order, then in the handover in S413b, both the terminal and base station 3 select NCC=1 and the corresponding K from the NCC list configured by base station 3 (the NCC list in S405). gNB* .

[0206] exist Figure 6d Based on this, assuming the S413b handover is successful, the terminal records the NCC=1 used in this handover and the result indicating a successful handover, or, records NCC=1 and the corresponding K gNB* Marked as used.

[0207] based on Figure 6d The process shown will continue as follows: if the terminal subsequently switches to base station 2 again, the process will proceed according to... Figure 6a The S413a selection key is shown. Figure 6a Taking two consecutive handovers to base station 2 as an example, the subsequent handover to base station 2 described here is not continuous with the previous handover to base station 2.

[0208] remove Figures 6a-6d In addition to the process shown, it is also possible that an RLF occurs in the source cell where the terminal is located, and the terminal does not receive the LTM cell handover instruction. In this case, it is equivalent to the terminal not performing the first handover, which does not affect the selection of NCC.

[0209] Figure 7 This is yet another method for processing key information provided in the embodiments of this application, and... Figures 6a-6d The difference between the two processes is that the NCC processing instruction information is provided by the source base station.

[0210] Figure 7 The process includes the following steps:

[0211] S501, The terminal sends the measurement results to base station 1.

[0212] S502, Base station 1 sends an LTM handover request message (i.e., the first handover request message) to base station 2.

[0213] S503, Base station 2 sends an LTM handover request response (i.e., the first handover request response) to base station 1.

[0214] S504, Base station 1 sends an LTM handover request message (i.e., the second handover request) to base station 3.

[0215] S505, Base Station 3 sends an LTM handover request response (i.e., the second handover request response) to Base Station 1.

[0216] In this embodiment, the LTM handover request responses returned by base stations 2 and 3 do not include NCC processing indication information. Instead, the NCC processing indication information is configured by base station 1, which is the source base station, and will be explained in subsequent steps.

[0217] S506, Base Station 1 sends an RRC reconfiguration message to the terminal.

[0218] In this embodiment, the RRC reconfiguration message includes the key list of each base station (base station 1, base station 2, and base station 3), NCC processing instruction information, and the identifier of the corresponding base station.

[0219] In this step, base station 1 can configure different NCC processing indication information for the key lists of base station 2 and base station 3, or it can configure the same NCC processing indication information. The NCC processing indication information of base station 1 and base station 2 or base station 3 can be the same or different.

[0220] Figure 7 In this example, we take the case where the NCC processing indication information of each base station indicates that the data should be discarded.

[0221] S507. The terminal sends an RRC reconfiguration complete message to base station 1.

[0222] S508, Base Station 1 sends an LTM cell handover command to the terminal.

[0223] In this embodiment, it is assumed that base station 1 selects base station 2 as the target base station, and the LTM cell handover instruction instructs the terminal to hand over from base station 1 to base station 2.

[0224] S509, Base Station 1 sends NCC processing instruction information to the target base station.

[0225] In this embodiment, the processing method indicated by the NCC processing instruction information is to retain, discard, or reset the value. Figure 7 In this example, we take the NCC's processing of the instruction information indicating that the information should be discarded as an example.

[0226] It is understood that the NCC processing instruction information in this step is the same as the processing instruction information in S506, that is, the source base station configures the same NCC processing instruction information to the terminal and the target base station to ensure that the terminal and the target base station use matching keys.

[0227] Base station 1 can use signaling in existing communication standards, such as LTM cell handover instructions sent to the target base station, or use signaling that may be newly written into the standard in the future, to instruct the target base station to process the instruction information by the NCC.

[0228] S510, the terminal failed to switch from base station 1 to base station 2.

[0229] In this embodiment, the terminal uses NCC=2 in the NCC list corresponding to base station 2 and the corresponding first key as an example in the handover process of this step.

[0230] S511. The terminal records that NCC=1 of base station 2 was used for this handover, as well as information indicating that the handover failed.

[0231] S512, The terminal performs cell selection.

[0232] Here we assume that the terminal still selects the cell of base station 2.

[0233] S513, the terminal switches from base station 1 to base station 2.

[0234] Because the NCC processing indication information configured in the source base station is discarded, in the event of an S510 handover failure, during the subsequent handover process from base station 1 to base station 2, neither the terminal nor base station 2 will use NCC=1; instead, they will use other unused NCCs. Figure 7 Taking NCC=2 and the corresponding first key as an example.

[0235] Understandably, an alternative approach is as follows: in S506 and S509, the configured NCC processing indication information is retained, and in S513, the terminal and base station 2 select NCC=1 and the corresponding first key.

[0236] Another alternative is that in S506 and S509, the configured NCC processing indication information indicates a reset value, such as NCC=5. In S513, the terminal and base station 2 select NCC=5 and the corresponding first key.

[0237] Figure 7 The process shown involves the source base station configuring NCC processing indication information for each candidate base station to the terminal, and sending NCC processing indication information to the target base station after sending the LTM cell handover command, without requiring the candidate base stations to be pre-configured.

[0238] Figure 8a This application provides another key processing method, which differs from the previous embodiments in that it is applied in the following scenario where candidate base stations share keys: The core network configures an NCC list for the terminal, and this NCC list is shared by all candidate base stations of the terminal. The core network provides this NCC list to the source base station, which 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 shared NCC list and corresponding keys of each candidate base station are then sent to the terminal via an RRC reconfiguration message. Figure 8a In the process, before the initial handover (i.e. the first handover) procedure, base station 1 is the source base station, and base stations 2 and 3 are candidate base stations.

[0239] In this scenario, this embodiment describes the use of NCC (Network Control Center) for inter-base station interaction.

[0240] Figure 8a The process includes the following steps:

[0241] S601 and AMF send the NCC list to base station 1.

[0242] The shared NCC list includes multiple NCC values, which are arranged in order. Examples of multiple NCC values ​​are: 1, 2, 3...

[0243] In some implementations, both the terminal and the base station are pre-configured to use the NCC list in ascending order of NCC values. For example, NCC=1 is used first, followed by NCC=2, then NCC=3, and so on.

[0244] The difference between this step and the above embodiment is that each candidate base station (e.g.) Figure 8a Base stations 2 and 3 shown in the diagram share the same NCC list.

[0245] In this embodiment, it is assumed that base station 1 is the source base station, so AMF configures a shared NCC list to the source base station.

[0246] Understandable Figure 8a The example provided is AMF, but this is not a limitation; the NCC list can also be configured and shared by other network elements in the core network.

[0247] S602, The terminal sends the measurement results to base station 1.

[0248] S603, Base station 1 sends an LTM handover request message (i.e., the first handover request message) to base station 2.

[0249] In this embodiment, the LTM handover request message sent by the source base station to other base stations includes a key list.

[0250] The key list includes multiple sets of keys, and each set of keys includes the corresponding first key K. gNB* The NCC value is an NCC value from the shared NCC list sent by the AMF in S601, and the first key K corresponding to this NCC value is... gNB* The value is the first key K generated using this NCC value. gNB* value.

[0251] S604, Base station 2 sends an LTM handover request response (i.e., the first handover request response) to base station 1.

[0252] In this embodiment, the first switching request response does not include NCC processing instruction information.

[0253] The first handover request response includes a list of NCCs, which includes the NCCs in the key list, i.e., a shared list of NCCs.

[0254] S605, Base station 1 sends an LTM handover request message (i.e., the second handover request) to base station 3.

[0255] The second switching request includes a list of keys.

[0256] It is understandable that, because each base station shares the NCC list, multiple first keys K are generated based on the NCC list. gNB* Since the values ​​are the same, the key lists sent by base station 1 to base station 2 and base station 3 are the same, which is called the shared key list.

[0257] S606, Base station 3 sends an LTM handover request response (i.e., the second handover request response) to base station 1.

[0258] The second switch request response does not include NCC processing instructions.

[0259] The second handover request response includes a list of NCCs, which includes the NCCs in the shared key list, i.e., a shared list of NCCs.

[0260] S607, Base Station 1 sends an RRC reconfiguration message to the terminal.

[0261] In this step, the RRC reconfiguration message includes a shared key list and NCC processing instructions.

[0262] The NCC processing instruction indicates whether to retain, discard, or reset the value. Figure 8a In this example, we take the NCC's instruction information retention as an example.

[0263] In this embodiment, since the base stations use a shared NCC list, all base stations use the same key (i.e., a shared key list). Therefore, the RRC reconfiguration message no longer needs to include the correspondence between the identifiers of each base station and the key list.

[0264] S608, The terminal sends an RRC reconfiguration complete message to base station 1.

[0265] S609, Base Station 1 sends an LTM cell handover command to the terminal.

[0266] The LTM cell handover command instructs base station 1 to select the target base station.

[0267] S610, Base Station 1 sends NCC processing instruction information and candidate base station information to the target base station for handover.

[0268] The NCC processing instruction information sent in this step is the same as the NCC processing instruction information sent to the terminal in S607, so that the terminal and the target base station can maintain consistency in their NCC processing. Figure 8a In this example, the NCC processing instruction information sent in this step indicates that the instruction should be retained.

[0269] In this step, in addition to sending NCC processing instruction information, base station 1 also sends information about candidate base stations, such as the identifiers of the candidate base stations. For example, if the candidate base stations include base station 2 and base station 3, then base station 1 also sends the identifier of base station 3 to base station 2.

[0270] S611. The terminal responds to the LTM cell handover command and switches from base station 1 to base station 2.

[0271] Figure 8a In this step, we take the example of the terminal using shared NCC=1. We assume here that the terminal successfully switched from base station 1 to base station 2.

[0272] S612, Base station 2 sends NCC usage information to base station 3.

[0273] Because multiple base stations share a key, the target base station needs to share the NCC usage information for this handover with other candidate base stations. In this step, base station 2, acting as the target base station, sends NCC usage information to other base stations.

[0274] In some implementations, the NCC usage information refers to the NCC value used in the current operation. In other implementations, the NCC usage information refers to unused NCC values, including all unused NCC values ​​in the shared NCC list. In yet another implementation, the NCC usage information refers to the NCC value to be used during the next switch.

[0275] It is also possible that the NCC usage information includes at least two of the above three types, such as the NCC usage information including unused NCC values ​​and the NCC values ​​to be used in the next switch.

[0276] Taking the NCC=1 used in this handover as an example, and assuming the handover from base station 1 to base station 2 was successful, the unused NCCs in this handover are 2, 3, ..., and the NCC to be used next time will be 2. Figure 8a As shown, base station 2 sends NCC usage information to base station 3, which is either NCC used this time = 1, NCC used next time = 2, or an unused NCC value.

[0277] Understandably, base station 2 sends NCC usage information to base station 3 based on the identifier previously received from base station 3.

[0278] Assuming the handover is successful, S611 explains that the handover process shown in S611 may still fail. The following describes scenarios of handover failure, including... Figure 8a The steps within the dashed box:

[0279] S613, The terminal failed to switch from base station 1 to base station 2.

[0280] S614. The terminal records the NCC value used in this handover and the information indicating that the handover failed.

[0281] S615, Base Station 2 sends NCC usage information to Base Station 3.

[0282] In the event of a handover failure, the NCC usage information sent by the target base station to other candidate base stations differs from that in the event of a successful handover. To distinguish between them, the NCC usage information sent in a successful handover is referred to as the first NCC usage information, and the NCC usage information sent in a failed handover is referred to as the second NCC usage information.

[0283] In some implementations, the second usage information for the NCC includes: the NCC value used in this switchover and the NCC processing instruction information. Figure 8a Taking S615 as an example, the second usage information of NCC includes: NCC used in this switch = 1, and reserved.

[0284] In this case, base station 3, which receives the second usage information of NCC, is able to determine that the next handover will use NCC=1.

[0285] In some other implementations, the second usage information of the NCC includes at least one of the following: an unused NCC value or a NCC value to be used next.

[0286] After a handover failure, the terminal selects a cell and initiates another handover, as follows:

[0287] S616, the terminal selects a cell.

[0288] Here we assume that the terminal selects cell 3 of base station.

[0289] S617, The terminal switches from base station 1 to base station 3.

[0290] Based on the S615 configuration, this switchover uses NCC=1. Assuming this switchover is successful, proceed to S617.

[0291] S617, Base Station 3 sends the first usage information of NCC to other base stations.

[0292] The first usage information of the NCC sent in this step can be found in S612, and will not be repeated here.

[0293] Figure 8a In the example of NCC processing instructions indicating retention, NCC processing instructions may also indicate discarding or resetting the value.

[0294] against Figure 8a The process shown can be replaced by an alternative method such as... Figure 8b As shown: In S607, the NCC processing indication information indicates discarding; in S610, base station 1 configures the NCC processing indication information indicating discarding and the identifier of base station 3 to base station 2. If the handover to base station 2 is successful and the handover uses NCC=1, in S612, base station 2 sends base station 3 either the currently used NCC=1, an unused NCC value, or the NCC value to be used next time. If the handover to base station 2 fails and the handover uses NCC=1, in S615, base station 2 sends base station 3 either the currently used NCC=1 and the NCC processing indication information indicating discarding, or base station 2 sends base station 3 either the unused NCC value, or the NCC value to be used next time.

[0295] Another alternative is as follows Figure 8c As shown: In S607, the NCC processing instruction information indicates a reset value, such as NCC=3. In S610, base station 1 configures the processing instruction information indicating the reset value and the identifier of base station 3 to base station 2. If the handover to base station 2 is successful and NCC=1 is used during the handover, in S612, base station 2 sends base station 3 either the currently used NCC=1, an unused NCC value, or NCC=2 for the next handover. If the handover to base station 2 fails and NCC=1 is used during the handover, in S615, base station 2 sends base station 3 either the currently used NCC=1 and the NCC processing instruction information indicating a reset value, or the unused NCC value and the NCC processing instruction information indicating a reset value, or NCC=3 (reset value) for the next handover.

[0296] In some cases, such as when NCC=1 is used during the handover to base station 2 and the reset value is NCC=3, subsequent handovers to base station 2 will use NCC=3, and NCC=2 will not be used. In some implementations, if the NCC values ​​in the NCC list are used sequentially, NCC=2 will be skipped and not used again. In other implementations, it is possible that NCC=2 will be used during subsequent handovers to base station 2.

[0297] Figures 8a-8cThe process shown allows base stations to share the NCC, improving NCC utilization. In scenarios involving multiple consecutive LTM handovers, the source base station configures NCC processing indication information to the target base station terminal, and the target base station notifies other candidate base stations of the NCC usage status, laying the foundation for the terminal and base station to use matching keys in subsequent handovers.

[0298] Figure 9a This application provides yet another key processing method for embodiments thereof, and Figures 8a-8c The difference in the process shown is that the source base station informs the core network equipment of the candidate base station information, the target base station informs the core network equipment of the NCC to be used in this handover, and the core network equipment notifies the candidate base station of the NCC usage information.

[0299] Figure 9a The process includes the following steps:

[0300] S701 and AMF send the NCC list to base station 1.

[0301] S702, The terminal sends the measurement results to base station 1.

[0302] S703, Base station 1 sends an LTM handover request message (i.e., the first handover request message) to base station 2.

[0303] For details on the implementation of this step, please refer to S603.

[0304] S704, Base station 2 sends an LTM handover request response (i.e., the first handover request response) to base station 1.

[0305] For details on the implementation of this step, please refer to S604.

[0306] S705, Base Station 1 sends an LTM handover request message (i.e., the second handover request) to Base Station 3.

[0307] S706, Base station 3 sends an LTM handover request response (i.e., the second handover request response) to base station 1.

[0308] S707, Base Station 1 sends an RRC reconfiguration message to the terminal.

[0309] For details on the implementation of this step, please refer to S707.

[0310] S708, The terminal sends an RRC reconfiguration complete message to base station 1.

[0311] S709, Base Station 1 sends an LTM cell handover command to the terminal.

[0312] S710: The terminal responds to the LTM cell handover command and switches from base station 1 to base station 2.

[0313] In this step, we take the example of the terminal using shared NCC=1. We assume here that the terminal successfully switched from base station 1 to base station 2.

[0314] S711, Base Station 1 sends candidate base station information to AMF.

[0315] In this step, the information about the candidate base stations is exemplified by their identifiers. If multiple candidate base stations exist, a list of their identifiers is sent.

[0316] S712, Base Station 2 sends the NCC value used for this handover to AMF.

[0317] Figure 9a In this example, we will use NCC=1 for this switch.

[0318] S713 and AMF send NCC usage information to base station 3.

[0319] In this step, because NCC management is performed by the AMF, the NCC usage information includes: unused NCC values, and at least one NCC value to be used during the next switchover. Figure 8a The difference is that, Figure 8a Since the NCC is managed by the base station, the NCC usage information in S612 and S617 can be the NCC value used this time, but this step does not include the NCC used this time.

[0320] It is understood that in this embodiment, the candidate base stations are assumed to be base station 2 and base station 3. Since base station 2 participated in this handover, the NCC used in this handover is known. Therefore, the AMF does not need to send the NCC usage information to base station 2 again. However, this is not a limitation, and the AMF can also send the NCC usage information to base station 2.

[0321] like Figure 9a As shown in S713, since NCC=1 was used in this switchover, NCC=2 will be used in the next switchover.

[0322] The following explains the situation where the terminal fails to hand over from base station 1 to base station 2:

[0323] S714, The terminal failed to switch from base station 1 to base station 2.

[0324] S715, Base Station 1 sends information about the candidate base station, the NCC value used in this handover, and NCC processing instruction information to AMF.

[0325] It is understandable that the NCC processing instruction information sent to the AMF is the same as the NCC processing instruction information configured to the terminal in S707. Figure 9a China and Israel retain this as an example.

[0326] S716 and AMF send NCC usage information to base station 3.

[0327] In this step, the NCC usage information includes at least one of the following: unused NCC values ​​and the NCC values ​​to be used in the next handover. Both the unused NCC values ​​and the NCC values ​​to be used in the next handover are determined by the AMF based on the NCC values ​​to be used in this handover and the NCC processing instruction information.

[0328] Continuing with the previous example, because the handover performed by S714 failed, and the NCC processing instruction information indicates that it should be retained, the next handover will still use NCC=1.

[0329] S717 The terminal records the NCC value used in this handover and information indicating handover failure.

[0330] S718, the terminal selects a cell.

[0331] Here we assume that the terminal selects cell 3 of base station.

[0332] S719, the terminal switches from base station 1 to base station 3.

[0333] Based on the NCC processing indication information, the terminal uses NCC=1 during the handover in this step. Based on the information sent by S716, base station 3 also uses NCC=1.

[0334] Assuming the terminal successfully switches from base station 1 to base station 3, the following steps are executed:

[0335] S720 and base station 3 send the NCC value used for this handover to AMF.

[0336] Following the previous example, this time the NCC used for switching is 1.

[0337] S721 and AMF send NCC usage information to base station 2.

[0338] Information on the use of NCC in this step can be found in S713, and will not be repeated here.

[0339] Understandably, the AMF sends NCC usage information to candidate base stations, taking base station 2 as an example, based on the information received from the candidate base stations.

[0340] After the terminal successfully switches from base station 1 to base station 3, base station 1 can send candidate base station information to the AMF again. Since this is not the first time switching from base station 1 to base station 3, base station 1 may also choose not to send candidate base station information to the AMF again. This is not a limitation.

[0341] Figure 9aThe key information configuration process shown involves the core network determining the NCC usage and distributing NCC usage information to each candidate base station. In addition to supporting the key requirements for multiple consecutive handovers between base stations in LTM scenarios, it eliminates the need for base stations to exchange NCC information, thus saving base station resources.

[0342] against Figure 9a An alternative implementation is as follows: Figure 9b As shown: In S707, the NCC processing indication information in the RRC reconfiguration message sent by base station 1 to the terminal indicates that the handover should be discarded. If the terminal successfully hands over from base station 1 to base station 2, in S711, base station 1 sends the candidate base station identifier to the AMF. In S712, base station 2 sends the NCC value used in this handover (NCC=1) to the AMF. In S713, the AMF sends the NCC value used in this handover (i.e., NCC=1) to base station 3, or the NCC value used in the next handover (NCC=2). If the terminal fails to hand over from base station 1 to base station 2, in S715, base station 1 sends the candidate base station identifier, the NCC value used in this handover (NCC=1), and the NCC processing indication information indicating discarding to the AMF. In S716, the AMF sends the NCC value used in this handover to base station 3, or the NCC value used in the next handover (NCC=2). It can be understood that because the NCC processing indication information indicates discarding, in the case of a failed handover, the next handover will use NCC=2.

[0343] against Figure 9a Another alternative implementation is as follows: Figure 9c As shown: The NCC processing instruction information configured by S707 base station 1 to the terminal indicates the reset value. In the event of a successful handover, the information exchanged between the source base station, the target base station, and the AMF is shown below. Figure 9a or Figure 9b In the event that the handover from base station 1 to base station 2 fails, in S715, base station 1 sends the identifier of the candidate base station, along with NCC=1 and an NCC processing indication indicating a reset value, to the AMF. In S716, the AMF sends the NCC value used in this handover and the reset value, or the NCC value to be used in the next handover, to base station 3.

[0344] Understandably, regarding Figures 9a-9c An alternative implementation is as follows: In S711, the terminal, instead of the source base station, sends the candidate base station information to the AMF. Furthermore, instead of the target base station sending the NCC value used for this handover to the AMF (i.e., S712 is not executed), the terminal sends the NCC value used for this handover to the AMF. In other words, the terminal sends the candidate base station information and the NCC value used for this handover to the AMF.

[0345] Specifically, in some implementations, if the handover fails, the terminal sends the candidate base station information, the NCC value used for this handover, and NCC processing instruction information to the AMF. In other implementations, if the handover succeeds, the terminal sends the candidate base station information and the NCC value used for this handover to the AMF.

[0346] AMF determines the NCC usage information based on the information sent by the terminal and distributes it to each candidate base station. For detailed steps, please refer to [link / reference needed]. Figures 9a-9c This will not be elaborated upon here.

[0347] In some of the embodiments above, only the use of the NCC value is described for ease of description. However, it is understood that when the use or selection of the NCC value is mentioned without mentioning the first key, it actually means the use or selection of the NCC value and the corresponding first key.

[0348] Figure 10 This is a structural example diagram of a terminal disclosed in an embodiment of this application. Taking a mobile phone as an example, it 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, etc.

[0349] It is understood that the structure illustrated in this embodiment does not constitute a specific limitation on the terminal. In other embodiments, the terminal may include more or fewer components than illustrated, or combine some components, or split some components, or have different component arrangements. The illustrated components may be implemented in hardware, software, or a combination of software and hardware.

[0350] Processor 310 may include one or more processing units, such as application processor (AP), modem processor, graphics processing unit (GPU), image signal processor (ISP), controller, video codec, digital signal processor (DSP), baseband processor, and / or neural network processing unit (NPU). These different processing units may be independent devices or integrated into one or more processors.

[0351] The external storage interface 320 can be used to connect an external storage card, such as a Micro SD card, to expand the terminal's storage capacity. The external storage card communicates with the processor 310 through the external storage interface 320 to perform data storage functions. For example, music, video, and other files can be saved on the external storage card.

[0352] Internal memory 321 can be used to store executable program code, including instructions. Processor 310 executes various terminal functions and data processing by running the instructions stored in internal memory 321. Internal memory 321 may include a program storage area and a data storage area. The program storage area may store the operating system, at least one application program required for a function (such as sound playback, image playback, etc.), etc. The data storage area may store data created during terminal use (such as audio data, phonebook, etc.). Furthermore, internal memory 321 may include high-speed random access memory and may also include non-volatile memory, such as at least one disk storage device, flash memory device, universal flash storage (UFS), etc. Processor 310 executes various terminal functions and data processing by running instructions stored in internal memory 321 and / or instructions stored in memory located within the processor.

[0353] The terminal's wireless communication function can be implemented through antenna 1, antenna 2, mobile communication module 350, wireless communication module 360, modem processor, and baseband processor.

[0354] Antenna 1 and antenna 2 are used to transmit and receive electromagnetic wave signals. Each antenna in the terminal can be used to cover one or more communication frequency bands. Different antennas can also be reused to improve antenna utilization. For example, antenna 1 can be reused as a diversity antenna for a wireless local area network. In some other embodiments, the antennas can be used in conjunction with a tuning switch.

[0355] The mobile communication module 350 can provide solutions for wireless communication applications including 2G / 3G / 4G / 5G in terminals. The mobile communication module 350 may include at least one filter, switch, power amplifier, low-noise amplifier (LNA), etc. The mobile communication module 350 can receive electromagnetic waves via antenna 1, and perform filtering, amplification, and other processing on the received electromagnetic waves before transmitting them to a modem processor for demodulation. The mobile communication module 350 can also amplify the signal modulated by the modem processor and convert it into electromagnetic waves for radiation via antenna 1. In some embodiments, at least some functional modules of the mobile communication module 350 may be housed in the processor 310. In some embodiments, at least some functional modules of the mobile communication module 350 and at least some modules of the processor 310 may be housed in the same device.

[0356] In some embodiments, the terminal initiates or receives call requests via the mobile communication module 350 and the antenna 1.

[0357] In addition, an operating system runs on top of the aforementioned components. Examples include iOS, Android, and Windows. Applications can be installed and run on this operating system.

[0358] Figure 11 This is a structural example diagram of a base station 900 disclosed in an embodiment of this application, including parts 910, 920, and 930. Part 910 is mainly used for baseband processing and base station control; part 910 is typically the control center of the base station, often referred to as a processor, used to control the base station to perform the processing operations on the network device side in the above method embodiments. Part 920 is mainly used to store computer program code and data. Part 930 is mainly used for the transmission and reception of radio frequency signals and the conversion between radio frequency signals and baseband signals; part 930 is often referred to as a transceiver module, transceiver, transceiver circuit, or transceiver. The transceiver module of part 930, also referred to as a transceiver, 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 device in part 930 used to implement the receiving function can be regarded as a receiver, and the device used to implement the transmitting function can be regarded as a transmitter, that is, part 930 includes a receiver 932 and a transmitter 931. A receiver can also be called a receiving module, receiver, or receiving circuit, while a transmitter can be called a transmitting module, transmitter, or transmitting circuit.

[0359] Sections 910 and 920 may include one or more circuit boards, each of which may include one or more processors and one or more memories. The processors are used to read and execute programs from the memories to implement baseband processing functions and control the base station. If multiple circuit boards exist, they can be interconnected to enhance processing capabilities. As an alternative implementation, multiple circuit boards may share one or more processors, multiple circuit boards may share one or more memories, or multiple circuit boards may simultaneously share one or more processors.

[0360] For example, in one implementation, the transceiver module in section 930 is used to execute the transceiver-related processes performed by the base station in the above embodiments. The processor in section 910 is used to execute the processing-related processes performed by the base station in the above embodiments.

[0361] It should be understood that Figure 11 This is merely an example and not a limitation; the base station described above, including the processor, memory, and transceiver, may not depend on... Figure 11 The structure shown.

[0362] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A key processing method, characterized in that, Applied to a terminal, the method includes: In response to a mobility LTM cell handover command triggered by Layer 1 or Layer 2, a first key is used in a first handover procedure, the first key including a first NCC value, and the target base station of the first handover procedure is a first base station; If the first handover process fails, then when the first base station is selected as the target base station for the second handover process, a second key is used in the second handover process. The second key includes an NCC value obtained based on at least one of NCC processing indication information and the first NCC value. The NCC processing indication information is used to indicate the processing method for the first NCC value.

2. The method according to claim 1, characterized in that, The NCC processing instruction information indicates that the first NCC value should be retained; The NCC value obtained based on at least one of the NCC processing instruction information and the first NCC value includes: The first NCC value.

3. The method according to claim 1, characterized in that, The NCC processing instruction information indicates that the first NCC value should be discarded; The NCC value obtained based on at least one of the NCC processing instruction information and the first NCC value includes: The second NCC value is different from the first NCC value.

4. The method according to claim 1, characterized in that, The NCC processing instruction information indicates a reset value, and the reset value is a third NCC value; The NCC value obtained based on at least one of the NCC processing instruction information and the first NCC value includes: The reset value.

5. The method according to any one of claims 1-4, characterized in that, Before executing the second switching procedure, the following is also included: The first NCC value and the identification information of the target base station in the first handover process are recorded. The second key is determined based on the first NCC value, the identification information, and the NCC processing instruction information.

6. The method according to any one of claims 1-5, characterized in that, Before receiving the LTM cell handover command, the process also includes: Receive key configuration information, which includes the NCC processing instruction information.

7. The method according to claim 6, characterized in that, The key configuration information also includes: A list of NCCs corresponding to candidate base stations, wherein the candidate base stations include the first base station; The use of the first NCC value in the first handover process includes: From the NCC list corresponding to the first base station, select the first NCC value that was not used in the handover process for the first handover process.

8. The method according to any one of claims 1-7, characterized in that, Also includes: When a second base station is selected as the target base station for the second handover process, a fourth NCC value that is not used in the handover process is selected from the NCC list corresponding to the second base station for the second handover process. The second base station is different from the first base station.

9. The method according to any one of claims 1-8, characterized in that, Also includes: After the first handover process, information about candidate base stations and the NCC usage information in the first handover process are sent to the core network equipment. The NCC usage information in the first handover process includes the first NCC value and the NCC processing instruction information.

10. The method according to any one of claims 1-9, characterized in that, Also includes: If the first handover process is successful, the candidate base station information is sent to the core network equipment.

11. A key processing method, characterized in that, The method, applied to a target base station for LTM handover, includes: In response to an LTM cell handover command, during the first handover process in which the terminal hands over to the target base station, a first key is used, the first key including a first NCC value; In the event that the first handover process fails, in the second handover process where the terminal switches to the target base station, a second key is used. The second key includes an NCC value obtained based on at least one of NCC processing indication information and the first NCC value. The NCC processing indication information is used to indicate the processing method for the first NCC value.

12. The method according to claim 11, characterized in that, The NCC processing instruction information indicates that the first NCC value should be retained; The NCC value obtained based on at least one of the NCC processing instruction information and the first NCC value includes: The first NCC value.

13. The method according to claim 11, characterized in that, The NCC processing instruction information indicates that the first NCC value should be discarded; The NCC value obtained based on at least one of the NCC processing instruction information and the first NCC value includes: The second NCC value is different from the first NCC value.

14. The method according to claim 11, characterized in that, The NCC processing instruction information indicates a reset value, and the reset value is a third NCC value; The NCC value obtained based on at least one of the NCC processing instruction information and the first NCC value includes: The reset value.

15. The method according to any one of claims 11-14, characterized in that, Before executing the second switching procedure, the following is also included: The first NCC value and the identification information of the target base station in the first handover process are recorded. The second key is determined based on the first NCC value, the identification information, and the NCC processing instruction information.

16. The method according to any one of claims 11-15, characterized in that, Before receiving the LTM cell handover command, the process also includes: Configure the NCC processing instruction information on the source base station switching to LTM.

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

18. The method according to any one of claims 11-15, characterized in that, Also includes: Send the NCC usage information from the first handover process to the candidate base stations of LTM.

19. The method according to claim 18, characterized in that, The NCC usage information includes: The NCC usage information in the first handover process, or the unused NCC value in the pre-configured NCC value corresponding to the target base station, or the NCC value used when switching to the target base station again.

20. The method according to claim 19, characterized in that, If the first switching process fails, the NCC usage information in the first switching process includes: the NCC value used in the first switching process and the NCC processing instruction information; The first switching process was successful. The NCC usage information in the first switching process includes: the NCC value used in the first switching process.

21. The method according to claims 11-20, characterized in that, Also includes: If the first handover process is successful, the NCC value used in the first handover process is sent to the core network equipment.

22. A key processing method, characterized in that, The method, applied to the source base station for LTM handover, includes: Configure the terminal with key information corresponding to the candidate base station, the key information including NCC processing instruction information; Send an LTM cell handover instruction to the terminal, the LTM cell handover instruction instructing the terminal to initiate a first handover procedure to hand over to the first base station, the first handover procedure using a first key, the first key including a first NCC value; The NCC processing indication information is used to indicate the processing method for the first NCC value. In the event of a failure of the first handover process, at least one of the NCC processing indication information and the first NCC value is used to obtain a second key used in the second handover process. The second key includes a second NCC value. The first handover process and the second handover process have the same target base station.

23. The method according to claim 22, characterized in that, Before configuring NCC processing instruction information to the terminal, the method further includes: Receive the NCC processing instruction information sent by the target base station.

24. The method according to claim 22, characterized in that, After sending the LTM cell handover command to the terminal, the method further includes: The NCC processing instruction information is sent to the target base station.

25. The method according to claim 24, characterized in that, After sending the LTM cell handover command to the terminal, the method further includes: The information of the candidate base station is sent to the target base station.

26. The method according to claim 22, characterized in that, After sending the LTM cell handover command to the terminal, the method further includes: The information of the candidate base stations is sent to the core network equipment.

27. The method according to claim 26, characterized in that, The first switching process failed; After sending the LTM cell handover command to the terminal, the method further includes: Send the NCC value used in the first handover process and the NCC processing instruction information to the core network equipment.

28. The method according to any one of claims 25-27, further comprising, before configuring the key information corresponding to the candidate base station to the terminal: The system receives an NCC list sent by the core network equipment, the NCC list including NCC values ​​shared by the candidate base stations.

29. A key processing method, characterized in that, When applied to core network equipment, the method includes: Send multiple NCC values ​​to the source base station of LTM; Receive key configuration information, which includes: information on candidate base stations for LTM, and information on the use of NCC in the first LTM handover process; Send at least one of two NCC values, namely an unused NCC value or a NCC value to be used next, to the candidate base station. The unused NCC value is the NCC value that was not used in the first LTM handover process among the plurality of NCC values, and the next time refers to the next LTM handover process after the first LTM handover process.

30. The method according to claim 29, characterized in that, The first LTM handover process was successful; The receiving key configuration information includes: The system receives the identifier of the candidate base station sent by the source base station in the first LTM handover process, and also receives the NCC value used in the first LTM handover process sent by the target base station in the first LTM handover process.

31. The method according to claim 29, characterized in that, The first LTM switching process failed; The receiving key configuration information includes: The key configuration information received from the source base station in the first LTM handover process includes: the identifier of the candidate base station, the NCC value used in the first LTM handover process, and NCC processing indication information.

32. A terminal, characterized in that, The terminal includes: 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, causing the terminal to implement the key processing method as described in any one of claims 1 to 10.

33. A base station, characterized in that, It includes a processor and a memory, the memory being used to store program code; the processor being used to run the program code, causing the base station to implement the key processing method as described in any one of claims 11 to 28.

34. A core network device, characterized in that, It includes a processor and a memory, the memory being used to store program code; the processor being used to run the program code, causing the core network device to implement the key processing method as described in any one of claims 29 to 31.

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