Communication method, terminals, communication system, and storage medium

Abstract

A communication method, terminals, a communication system, and a storage medium. The method, executed by a terminal, comprises: executing a mobility operation, and determining whether to perform key update. In this way, the security of mobility operations can be improved.

Description

Communication method, terminal, communication system and storage medium Technical Field

[0001] The present disclosure relates to the field of communication technologies, and in particular to a communication method, a terminal, a communication system, and a storage medium. Background Art

[0002] The fifth generation mobile communication technology (5G) introduces a variety of mobility enhancement technologies, such as conditional handover (CHO), conditional PSCell Addition / Change (CPAC), and layer L1 / L2 triggered mobility (LTM).

[0003] Summary of the Invention

[0004] The embodiments of the present disclosure provide a communication method, a terminal, a communication system, and a storage medium.

[0005] According to a first aspect of an embodiment of the present disclosure, a communication method is proposed, which is executed by a terminal. The method includes: performing a mobility operation and determining whether to perform a key update.

[0006] According to a second aspect of an embodiment of the present disclosure, a terminal is proposed, including: a processing module, configured to perform a mobility operation and determine whether to perform a key update.

[0007] According to the third aspect of an embodiment of the present disclosure, a terminal is proposed, comprising: one or more processors; a memory coupled to the processor, wherein the memory stores executable instructions, and when the executable instructions are executed by the processor, the terminal executes the communication method described in the first aspect.

[0008] According to a fourth aspect of an embodiment of the present disclosure, a communication system is proposed, including a terminal and a network device, wherein the terminal is configured to implement the communication method described in the first aspect.

[0009] According to a fifth aspect of an embodiment of the present disclosure, a storage medium is proposed, wherein the storage medium stores instructions. When the instructions are executed on a communication device, the communication device executes the communication method described in the first aspect.

[0010] By adopting the above technical solution of the present disclosure, at least the following beneficial technical effects can be achieved:

[0011] In response to triggering the execution of the mobility operation, the terminal can determine whether to perform a key update, thereby facilitating the terminal to decide whether to update the key based on the determination result, which can improve the security of the mobility operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following drawings required for describing the embodiments are introduced. The following drawings are merely some embodiments of the present disclosure and do not impose specific limitations on the protection scope of the present disclosure.

[0013] FIG1A is a schematic diagram showing the architecture of a communication system according to an embodiment of the present disclosure.

[0014] FIG1B is a schematic diagram of a network architecture according to an embodiment of the present disclosure.

[0015] FIG1C is a schematic diagram of a network architecture according to an embodiment of the present disclosure.

[0016] FIG1D is a schematic diagram of a network architecture according to an embodiment of the present disclosure.

[0017] FIG1E is a schematic diagram showing a key update according to an embodiment of the present disclosure.

[0018] FIG1F is a schematic diagram showing a key update configuration according to an embodiment of the present disclosure.

[0019] FIG2A is an interactive schematic diagram illustrating a communication method according to an embodiment of the present disclosure.

[0020] FIG2B is an interactive diagram illustrating a communication method according to an embodiment of the present disclosure.

[0021] FIG3A is a flow chart illustrating a communication method according to an embodiment of the present disclosure.

[0022] FIG3B is a flow chart illustrating a communication method according to an embodiment of the present disclosure.

[0023] FIG3C is a flow chart illustrating a communication method according to an embodiment of the present disclosure.

[0024] FIG3D is a flow chart of a communication method according to an embodiment of the present disclosure.

[0025] FIG3E is a flow chart of a communication method according to an embodiment of the present disclosure.

[0026] FIG3F is a flow chart of a communication method according to an embodiment of the present disclosure.

[0027] FIG3G is a flow chart of a communication method according to an embodiment of the present disclosure.

[0028] FIG3H is a flow chart of a communication method according to an embodiment of the present disclosure.

[0029] FIG3I is a flow chart of a communication method according to an embodiment of the present disclosure.

[0030] FIG3J is a flow chart of a communication method according to an embodiment of the present disclosure.

[0031] FIG3K is a flow chart of a communication method according to an embodiment of the present disclosure.

[0032] FIG3L is a flow chart of a communication method according to an embodiment of the present disclosure.

[0033] FIG4A is a flow chart showing a communication method according to an embodiment of the present disclosure.

[0034] FIG4B is a flow chart illustrating a communication method according to an embodiment of the present disclosure.

[0035] FIG5A is a schematic diagram of an identification setting code proposed according to an embodiment of the present disclosure.

[0036] FIG5B is a schematic diagram of an identification setting code according to an embodiment of the present disclosure.

[0037] FIG6A is a schematic structural diagram of a terminal according to an embodiment of the present disclosure.

[0038] FIG6B is a schematic diagram of the structure of a network device proposed according to an embodiment of the present disclosure.

[0039] FIG7A is a schematic structural diagram of a communication device proposed in an embodiment of the present disclosure.

[0040] FIG7B is a schematic diagram of the structure of the chip proposed in an embodiment of the present disclosure. DETAILED DESCRIPTION

[0041] The embodiments of the present disclosure provide a communication method, a terminal, a communication system, and a storage medium.

[0042] In a first aspect, an embodiment of the present disclosure proposes a communication method, which is executed by a terminal. The method includes: performing a mobility operation and determining whether to perform a key update.

[0043] In the above embodiment, in response to a trigger to perform a mobility operation, the terminal can determine whether to perform a key update. This facilitates the terminal to decide whether to update the key based on the determination result. Therefore, if a key update is required, the key can be updated, thereby improving the security of the mobility operation. Furthermore, if a key update is not required, the key can be omitted, thereby reducing terminal processing operations and reducing terminal complexity.

[0044] In combination with some embodiments of the first aspect, in some embodiments, the determining whether to perform a key update includes: determining whether to perform a key update based on first information, the first information including a first identifier associated with a service cell of the terminal and / or a second identifier associated with a first cell to which the terminal will access.

[0045] In the above embodiment, the terminal can quickly and accurately determine whether to perform a key update according to the first identifier and / or the second identifier included in the first information.

[0046] In combination with some embodiments of the first aspect, in some embodiments, the first information is configured by a network device for the terminal.

[0047] In the above embodiment, the network device can flexibly configure the first information on the terminal based on demand.

[0048] In combination with some embodiments of the first aspect, in some embodiments, determining whether to perform a key update based on the first information includes: performing a key update when the first identifier is different from the second identifier.

[0049] Optionally, one identifier corresponds to one access network device. Optionally, different identifiers represent different corresponding access network devices. Optionally, mobility between different access network devices requires key update.

[0050] In the above embodiment, according to the difference between the first identifier and the second identifier, it can be accurately determined that the key update is required.

[0051] In combination with some embodiments of the first aspect, in some embodiments, determining whether to perform a key update based on the first information includes: if the first identifier is the same as the second identifier, no key update is performed.

[0052] Optionally, one identifier corresponds to one access network device. Optionally, identical identifiers indicate identical corresponding access network devices. Optionally, mobility within the access network device does not require key updating.

[0053] In the above embodiment, since the first identifier is the same as the second identifier, it can be accurately determined that the key update is not required.

[0054] In combination with some embodiments of the first aspect, in some embodiments, determining whether to perform a key update based on the first information includes: performing a key update when the first information does not include the first identifier.

[0055] In the above embodiment, it is specified that when the first information does not include the first identifier, a key update is required.

[0056] In combination with some embodiments of the first aspect, in some embodiments, determining whether to perform a key update based on the first information includes: if the first information does not include the second identifier, no key update is performed.

[0057] In the above embodiment, it is specified that when the first information does not include the second identifier, no key update is required.

[0058] In combination with some embodiments of the first aspect, in some embodiments, the method further includes: receiving a first configuration sent by a network device, the first configuration including the first identifier; storing the first identifier in a first variable, the first variable being used to store an identifier associated with the service cell of the terminal.

[0059] In the above embodiment, the first identifier can be flexibly configured for the terminal through the first configuration.

[0060] In combination with some embodiments of the first aspect, in some embodiments, the first configuration also includes specific information for the post-configuration cell configuration, and the method also includes: updating at least one second configuration in the second variable according to the specific information, one second configuration corresponds to one candidate cell, and the second configuration includes the corresponding identifier of the candidate cell.

[0061] In the above embodiment, one or more second configurations can be flexibly configured / updated for the terminal through the first configuration.

[0062] In combination with some embodiments of the first aspect, in some embodiments, the first configuration is an LTM configuration.

[0063] In the above embodiment, the first identifier can be flexibly configured for the terminal through the LTM configuration, thereby improving the utilization rate of the LTM configuration.

[0064] In combination with some embodiments of the first aspect, in some embodiments, the second configuration is an LTM candidate cell configuration.

[0065] In combination with some embodiments of the first aspect, in some embodiments, after the key update, it includes: successfully accessing the first cell, updating the first variable according to the second identifier, and the first variable is used to store the identifier associated with the service cell of the terminal.

[0066] In the above embodiment, when the first cell is successfully accessed, the first variable may be updated according to the second identifier, so that the terminal can accurately respond to the next mobility operation.

[0067] In combination with some embodiments of the first aspect, in some embodiments, one identifier is associated with one key update related information, and the key update includes: performing the key update according to the key update related information associated with the second identifier.

[0068] In the above embodiment, when it is determined to perform key update, the key update can be accurately performed according to the key update related information associated with the second identifier.

[0069] In combination with some embodiments of the first aspect, in some embodiments, the key update related information includes one or more next hop chaining counter parameters NCC (the Next Hop Chaining Counter parameter); the key update based on the key update related information associated with the second identifier includes: the key update based on one NCC in the key update related information associated with the second identifier.

[0070] In the above embodiment, key update based on NCC is specified.

[0071] In combination with some embodiments of the first aspect, in some embodiments, the method further includes: storing at least one key update related information according to the LTM configuration.

[0072] In the above embodiment, it is specified that key update related information can be configured through LTM configuration.

[0073] In combination with some embodiments of the first aspect, in some embodiments, the key update related information on the terminal is added, updated, or removed by the network device through a third configuration.

[0074] In the above embodiment, it is specified that key update related information can be added, updated or removed through the third configuration.

[0075] In combination with some embodiments of the first aspect, in some embodiments, determining whether to perform a key update includes: receiving second information sent by a network device; and determining whether to perform a key update based on the second information.

[0076] In the above embodiment, an implementation method is proposed in which the terminal determines whether to perform key update according to the second information sent by the network device.

[0077] In combination with some embodiments of the first aspect, in some embodiments, determining whether to update the key based on the second information includes: the second information indicates that the key is updated, and the key update is performed; or the second information indicates that the key is not updated, and the key update is not performed.

[0078] In the above embodiment, the network device can clearly indicate to the terminal whether a key update is required through the second information, so that the terminal can quickly determine whether to perform a key update.

[0079] In combination with some embodiments of the first aspect, in some embodiments, the determining whether to perform a key update includes: receiving the second information before receiving the LTM cell switching command, and performing a key update; or not receiving the second information before receiving the LTM cell switching command, and not performing a key update.

[0080] In the above embodiment, the network device can indicate whether the terminal needs to update the key by whether it sends the second information at a specified time, so that the terminal can quickly determine whether to update the key based on whether it receives the second information at a specified time, which can reduce resource overhead.

[0081] In conjunction with some embodiments of the first aspect, in some embodiments, the second information includes a first cell list, where the first cell list is used to instruct the terminal to perform a key update when accessing a cell in the first cell list;

[0082] The determining whether to perform key update according to the second information includes: the first cell list includes the first cell to be accessed by the terminal, and key update is performed; or the first cell list does not include the first cell, and key update is not performed.

[0083] In the above embodiment, the terminal can quickly determine whether to perform key update by judging whether the first cell to be accessed is a cell in the first cell list.

[0084] In conjunction with some embodiments of the first aspect, in some embodiments, the second information includes a second cell list, where the second cell list is used to instruct the terminal not to perform a key update when accessing a cell in the second cell list;

[0085] The determining whether to perform key update according to the second information includes: the second cell list includes the first cell that the terminal will access, and key update is not performed; or the second cell list does not include the first cell, and key update is performed.

[0086] In the above embodiment, the terminal can quickly determine whether to perform key update by judging whether the first cell to be accessed is a cell in the second cell list.

[0087] In combination with some embodiments of the first aspect, in some embodiments, the second information is sent by the network device to the terminal after the terminal accesses a current serving cell.

[0088] In the above embodiment, the timing for the network device to send the first cell list / the second cell list to the terminal is regulated.

[0089] In combination with some embodiments of the first aspect, in some embodiments, the second information is sent by the network device through at least one of downlink control information DCI, media access control layer MAC message, and radio resource control RRC message.

[0090] In the above embodiment, the network device can flexibly select at least one of DCI, MAC message, and RRC message to send the second information to the terminal.

[0091] In conjunction with some embodiments of the first aspect, in some embodiments, the mobility operation includes at least one of the following:

[0092] Mobility LTM cell switching based on layer L1 / L2 triggering;

[0093] Condition-based switching CHO.

[0094] In the above embodiment, the mobility operation of the terminal is standardized as LTM cell handover or CHO.

[0095] In a second aspect, an embodiment of the present disclosure proposes a terminal, which includes at least one of a transceiver module and a processing module; wherein the terminal is used to execute an optional implementation method of the first aspect.

[0096] In a third aspect, an embodiment of the present disclosure proposes a terminal, which includes one or more processors; a memory coupled to the processor, on which executable instructions are stored, and when the executable instructions are executed by the processor, the terminal executes an optional implementation method of the first aspect.

[0097] In a fourth aspect, an embodiment of the present disclosure proposes a communication system, which includes a terminal and a network device, wherein the terminal is configured to execute the communication method described in the optional implementation manner of the first aspect.

[0098] In a fifth aspect, an embodiment of the present disclosure proposes a storage medium, which stores instructions. When the instructions are executed on a communication device, the communication device executes the method described in the optional implementation manner of the first aspect.

[0099] In a sixth aspect, an embodiment of the present disclosure proposes a program product. When the program product is executed by a communication device, the communication device executes the method described in the optional implementation manner of the first aspect.

[0100] In a seventh aspect, an embodiment of the present disclosure proposes a computer program, which, when executed on a computer, enables the computer to execute the method described in the optional implementation manner of the first aspect.

[0101] In an eighth aspect, an embodiment of the present disclosure provides a chip or a chip system, which includes a processing circuit configured to execute the method described in the optional implementation of the first aspect.

[0102] It is understandable that the above-mentioned terminals, communication systems, storage media, program products, computer programs, chips, or chip systems are all used to perform the methods proposed in the embodiments of the present disclosure. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects of the corresponding methods and will not be repeated here.

[0103] The present disclosure provides a communication method, terminal, communication system, and storage medium. In some embodiments, the terms "communication method," "information processing method," and "method for determining whether to perform a key update" are interchangeable; the terms "communication device," "information processing device," and "device for determining whether to perform a key update" are interchangeable; and the terms "communication system," "information processing system," and "update system for determining whether to perform a key update" are interchangeable.

[0104] The embodiments of the present disclosure are not exhaustive and are merely illustrative of some embodiments, and are not intended to be a specific limitation on the scope of protection of the present disclosure. In the absence of contradiction, each step in a certain embodiment can be implemented as an independent embodiment, and the steps can be arbitrarily combined. For example, a solution after removing some steps in a certain embodiment can also be implemented as an independent embodiment, and the order of the steps in a certain embodiment can be arbitrarily exchanged. In addition, the optional implementation methods in a certain embodiment can be arbitrarily combined; in addition, the embodiments can be arbitrarily combined. For example, some or all steps of different embodiments can be arbitrarily combined, and a certain embodiment can be arbitrarily combined with the optional implementation methods of other embodiments.

[0105] In each embodiment of the present disclosure, unless otherwise specified or provided for by logic, the terms and / or descriptions between the embodiments are consistent and can be referenced by each other. The technical features in different embodiments can be combined to form a new embodiment based on their inherent logical relationships.

[0106] The terms used in the embodiments of the present disclosure are only for the purpose of describing specific embodiments and are not intended to limit the present disclosure.

[0107] In the embodiments of the present disclosure, unless otherwise specified, elements expressed in the singular, such as "a", "an", "the", "above", "said", "the", "the", etc., may mean "one and only one", or "one or more", "at least one", etc. For example, when using articles such as "a", "an", "the" in English in translation, the noun following the article may be understood as a singular expression or a plural expression.

[0108] In the embodiments of the present disclosure, “plurality” refers to two or more.

[0109] In some embodiments, the terms "at least one," "one or more," "a plurality of," "multiple," etc. may be used interchangeably.

[0110] In some embodiments, descriptions such as "at least one of A and B," "A and / or B," "A in one case, B in another case," or "in response to one case A, in response to another case B" may include the following technical solutions depending on the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed); and in some embodiments, A and B (both A and B are executed). The above is also applicable when there are more branches such as A, B, and C.

[0111] In some embodiments, "A or B" and other descriptions may include the following technical solutions depending on the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed). The above is also applicable when there are more branches such as A, B, C, etc.

[0112] The prefixes such as "first" and "second" in the embodiments of the present disclosure are only used to distinguish different description objects and do not constitute any restriction on the position, order, priority, quantity or content of the description objects. For the statement of the description object, please refer to the description in the context of the claims or embodiments, and no unnecessary restriction should be constituted due to the use of prefixes. For example, if the description object is a "field", the ordinal number before the "field" in the "first field" and the "second field" does not limit the position or order between the "fields". "First" and "second" do not limit whether the "fields" they modify are in the same message, nor do they limit the order of the "first field" and the "second field". For another example, if the description object is a "level", the ordinal number before the "level" in the "first level" and the "second level" does not limit the priority between the "levels". For another example, the number of description objects is not limited by the ordinal number and can be one or more. Taking "first device" as an example, the number of "devices" can be one or more. In addition, the objects modified by different prefixes can be the same or different. For example, if the description object is "device", then the "first device" and the "second device" can be the same device or different devices, and their types can be the same or different; for another example, if the description object is "information", then the "first information" and the "second information" can be the same information or different information, and their contents can be the same or different.

[0113] In some embodiments, “including A,” “comprising A,” “used to indicate A,” and “carrying A” can be interpreted as directly carrying A or indirectly indicating A.

[0114] In some embodiments, terms such as "in response to...", "in response to determining...", "in the case of...", "at the time of...", "when...", "if...", "if...", etc. can be used interchangeably.

[0115] In some embodiments, terms such as "greater than", "greater than or equal to", "not less than", "more than", "more than or equal to", "not less than", "higher than", "higher than or equal to", "not less than", and "above" can be replaced with each other, and terms such as "less than", "less than or equal to", "not greater than", "less than", "less than or equal to", "not more than", "lower than", "lower than or equal to", "not higher than", and "below" can be replaced with each other.

[0116] In some embodiments, devices, etc. can be interpreted as physical or virtual, and their names are not limited to the names recorded in the embodiments. Terms such as "device", "equipment", "device", "circuit", "network element", "node", "function", "unit", "section", "system", "network", "chip", "chip system", "entity", and "subject" can be used interchangeably.

[0117] In some embodiments, "network" can be interpreted as devices included in the network (eg, access network equipment, core network equipment, etc.).

[0118] In some embodiments, the terms "access network device (AN device)", "radio access network device (RAN device)", "base station (BS)", "radio base station" "fixed station", "node", "access point", "transmission point (TP)", "reception point (RP)", "transmission / reception point (TRP)" "panel", "antenna panel", "antenna array", "cell", "macro cell", "small cell", "femto cell", "pico cell", "sector", "cell group", "serving cell", "carrier", "component carrier", "bandwidth part (BWP)" and the like may be used interchangeably.

[0119] In some embodiments, the terms "terminal", "terminal device", "user equipment (UE)", "user terminal", "mobile station (MS)", "mobile terminal (MT)", subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, etc. can be used interchangeably.

[0120] In some embodiments, the access network device, the core network device, or the network device can be replaced by a terminal. For example, the various embodiments of the present disclosure can also be applied to a structure in which the communication between the access network device, the core network device, or the network device and the terminal is replaced by communication between multiple terminals (for example, device-to-device (D2D), vehicle-to-everything (V2X), etc.). In this case, it is also possible to set the structure in which the terminal has all or part of the functions of the access network device. In addition, terms such as "uplink" and "downlink" can also be replaced by terms corresponding to communication between terminals (for example, "side"). For example, uplink channels, downlink channels, etc. can be replaced by side channels, and uplinks, downlinks, etc. can be replaced by side links.

[0121] In some embodiments, the terminal may be replaced by an access network device, a core network device, or a network device. In this case, the access network device, the core network device, or the network device may have a structure that has all or part of the functions of the terminal.

[0122] In some embodiments, obtaining data, information, etc. may comply with the laws and regulations of the country where the data is obtained.

[0123] In some embodiments, data, information, etc. may be obtained with the user's consent.

[0124] In addition, each element, each row, or each column in the table of the embodiment of the present disclosure can be implemented as an independent embodiment, and the combination of any elements, any rows, and any columns can also be implemented as an independent embodiment.

[0125] FIG1A is a schematic diagram illustrating an architecture of a communication system according to an embodiment of the present disclosure. As shown in FIG1A , the communication system 100 may include a terminal 101 and a network device 102 .

[0126] In some embodiments, the terminal 101 includes, for example, a mobile phone, a wearable device, an Internet of Things device, a car with communication function, a smart car, a tablet computer, a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal device in industrial control, a wireless terminal device in self-driving, a wireless terminal device in remote medical surgery, a wireless terminal device in a smart grid, a wireless terminal device in transportation safety, a wireless terminal device in a smart city, and at least one of a wireless terminal device in a smart home, but is not limited thereto.

[0127] In some embodiments, the network device 102 may include at least one of an access network device and a core network device.

[0128] Optionally, the network device 102 is an access network device. Optionally, the access network device is, for example, a node or device that connects a terminal to a wireless network. The access network device may include at least one of an evolved NodeB (eNB), a next generation evolved NodeB (ng-eNB), a next generation NodeB (gNB), a node B (NB), a home nodeB (HNB), a home evolved nodeB (HeNB), a wireless backhaul device, a radio network controller (RNC), a base station controller (BSC), a base transceiver station (BTS), a base band unit (BBU), a mobile switching center, a base station in a 6G communication system, an open RAN, a cloud RAN, a base station in other communication systems, and an access node in a Wi-Fi system, but is not limited thereto.

[0129] In some embodiments, the network device 102 is a base station. Optionally, the base station is, for example, a macro base station, a micro base station (also known as a small base station), a relay station, an access point, a 5G base station or a future base station, a satellite, a transmission point (TRP), a transmission point (TP), a mobile switching center, or other devices that perform base station functions in a communication system, etc., which are not specifically limited in the embodiments of the present disclosure. For ease of description, in all embodiments of the present disclosure, devices that provide wireless communication functions for terminal devices are collectively referred to as network devices or base stations.

[0130] In some embodiments, network device 102 is a core network device. Optionally, the core network device can be a single device including a first network element, a second network element, etc., or can be multiple devices or a group of devices, each including all or part of the first network element, the second network element, etc. The network element can be virtual or physical. The core network includes, for example, at least one of an Evolved Packet Core (EPC), a 5G Core Network (5GCN), and a Next Generation Core (NGC).

[0131] In some embodiments, the technical solution of the present disclosure can be applied to the Open RAN architecture. In this case, the interfaces between or within the access network devices involved in the embodiments of the present disclosure can be transformed into internal interfaces of the Open RAN, and the processes and information interactions between these internal interfaces can be implemented through software or programs.

[0132] In some embodiments, the access network device can be composed of a centralized unit (CU) and a distributed unit (DU), where the CU can also be called a control unit. The CU-DU structure can be used to split the protocol layer of the access network device, with the functions of some protocol layers centrally controlled by the CU, and the functions of the remaining part or all of the protocol layers distributed in the DU, which is centrally controlled by the CU, but is not limited to this.

[0133] It can be understood that the communication system described in the embodiment of the present disclosure is for the purpose of more clearly illustrating the technical solution of the embodiment of the present disclosure, and does not constitute a limitation on the technical solution proposed in the embodiment of the present disclosure. Ordinary technicians in this field can know that with the evolution of the system architecture and the emergence of new business scenarios, the technical solution proposed in the embodiment of the present disclosure is also applicable to similar technical problems.

[0134] The following embodiments of the present disclosure may be applied to the communication system 100 shown in FIG1A , or a portion thereof, but are not limited thereto. The entities shown in FIG1A are illustrative only. The communication system may include all or part of the entities shown in FIG1A , or may include other entities other than those shown in FIG1A . The number and form of the entities may be arbitrary, and the entities may be physical or virtual. The connection relationships between the entities are illustrative only. The entities may be connected or disconnected, and the connection may be in any manner, including direct or indirect, wired or wireless.

[0135] The embodiments of the present disclosure can be applied to Long Term Evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 5G new radio (NR), future radio access (FRA), new radio access technology (RAT), new radio (NR), new radio access (NX), future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), Public Land Mobile Network (PLMN) networks, Device-to-Device (D2D) systems, Machine-to-Machine (M2M) systems, Internet of Things (IoT) systems, Vehicle-to-Everything (V2X), systems utilizing other communication methods, and next-generation systems based on and extending these methods. Furthermore, multiple systems may be combined (for example, a combination of LTE or LTE-A with 5G).

[0136] In some embodiments, MR-DC (Multi-Radio Dual Connectivity) is a generalized Intra-E-UTRA (Intra Evolved Universal Terrestrial Radio Access, Intra-node Evolved Universal Mobile Telecommunications System (UMTS) terrestrial radio access) dual connectivity, in which the UE can utilize radio resources provided by two different schedulers, which are located on two different NG-RAN (New Generation Radio Access Network) nodes, connected through non-ideal backhaul, one providing NR (New Radio) access and the other providing E-UTRA or NR access. One acts as MN (MasterNode) and the other as SN (Secondary Node). The MN and SN are connected through a network interface, where at least one MN is connected to the core network.

[0137] In some embodiments, MR-DC and EPC (Evolved Packet Core, i.e., 4G core network):

[0138] Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) supports MR-DC through E-UTRA-NR DC (EN-DC), where the UE connects to an eNB (eNodeB) acting as a mobile node (MN) and an en-gNB (en-gNB), acting as a network node (SN). The eNB connects to the EPC (Packet Core) via the S1 interface (the S1 interface is the communication interface between the LTE eNodeB (base station) and the EPC) and to the en-gNB via the X2 interface (the X2 interface is the interconnection interface between e-NodeBs). The en-gNB can also connect to the EPC via the S1-U interface (the interface between the eNodeB and the S-GW, which is the user plane interface) and to other en-gNBs via the X2-U interface. The EN-DC architecture is shown in Figure 1B.

[0139] In some embodiments, the MR-DC of the 5G core network (5GC) includes one of the following:

[0140] A)E-UTRA-NR Dual Connectivity NGEN-DC:

[0141] NG-RAN supports NG-RAN E-UTRA-NR Dual Connectivity (NGEN-DC), where the UE is connected to a ng-eNB as a mobile node and a gNB as a network node. The ng-eNB is connected to the 5GC, and the gNB is connected to the ng-eNB via the Xn interface.

[0142] B)NR-E-UTRA Dual Connectivity NE-DC:

[0143] NG-RAN supports NR-E-UTRA DC (NE-DC), where the UE is connected to a gNB acting as a mobile node and an ng-eNB acting as a network node. The gNB is connected to the 5GC, and the ng-eNB is connected to the gNB via the Xn interface.

[0144] C)NR-NR Dual Connectivity:

[0145] NG-RAN supports NR-NR DC (NR-DC), in which a UE connects to a gNB acting as a mobile node and another gNB acting as a network station. The primary gNB connects to the 5GC via the NG interface, and the two gNBs connect to each other via the Xn interface. The secondary gNB can also connect to the 5GC via the NG-U interface. NR-DC can also be used for UEs to access a single gNB acting as both a mobile node and a network station, with both an MCG (Master Cell Group) and an SCG (Secondary Cell Group) configured. The NR-DC architecture is shown in Figure 1C.

[0146] In some embodiments, under dual connectivity, the UE can access two cell groups, namely the main cell group MCG and the secondary cell group SCG. Under the MCG, there may be many cells, among which there is a cell used to initiate initial access, which is called PCell (Primary Cell). As the name implies, PCell is the most "main" cell in the MCG. The PCell under the MCG and the SCell (Secondary Cell) under the MCG are combined through CA (Carrier Aggregation). The primary cell in the MCG is the PCell, and the secondary cell is the SCell; the primary and secondary cells in the SCG are the PSCell (Primary Secondary Cell), and the secondary cell is the SCell. Because many signalings are only sent on the PCell and PSCell, for the convenience of description, the protocol also defines a concept of special cell sPCell (special Cell). PCell and PSCell are collectively referred to as sPCell. Please refer to Figure 1D for details.

[0147] In some embodiments, LTM (L1 / L2 Triggered Mobility) is defined as follows: Rel-18 LTM refers to a PCell / PSCell cell switch process triggered by the network based on L1 measurement results via a MAC CE (Medium Access Control Control Element), which may be accompanied by a MCG / SCG change. The gNB receives L1 measurement reports from the UE and, based on these reports, issues a cell change command (e.g., a cell switch command) via a MAC CE to change the UE's serving cell. The cell switch command indicates an LTM candidate cell configuration that the gNB has previously provided to the UE via RRC (Radio Resource Control) signaling. The UE accesses the target cell indicated in the cell change command based on the received cell switch command. LTM can be used to reduce mobility latency.

[0148] In some embodiments, the LTM candidate cell configuration can only be added, modified, and released by the network through RRC signaling. The LTM process can be used to reduce mobility delay.

[0149] In some embodiments, for LTM, Rel-18 LTM supports subsequent LTM, where Subsequent LTM refers to subsequent LTM cell switch procedures between candidate cells without RRC reconfiguration by the network in between. That is, after performing a mobility operation, the UE does not autonomously delete the LTM configuration information. The LTM configuration information can continue to be used to trigger subsequent LTM (Subsequent LTM) even without RRC reconfiguration and update.

[0150] In some embodiments, a gNB can include a centralized unit (CU) and a distributed unit (DU). This splits the base station's functionality, deploying some functions in a gNB-CU and the remaining functions in a gNB-DU. Multiple gNB-DUs share a single gNB-CU, saving costs and facilitating network expansion. RE1-18 LTM supports the following scenarios:

[0151] LTM supports intra-gNB-DU and intra-gNB-CU inter-gNB-DU mobility. LTM supports intra-frequency and inter-frequency mobility, including mobility to an inter-frequency cell that is not the current serving cell. The following scenarios are supported:

[0152] Changes in PCell in non-CA and non-DC scenarios;

[0153] PCell changes in CA scenarios;

[0154] In the dual connectivity solution, MCG PCell changes and SCG PSCell changes are performed without MN participation (i.e., PSCell changes within SN). Simultaneous changes of PCell and PSCell LTM are not supported.

[0155] In some embodiments, only intra-DU and inter-DU intra-CU LTMs are supported in Rel-18. However, Rel-19 will expand support for inter-CU (inter-node / gNB) LTMs. The mobile network (MN) participates in inter-CU (inter-node / gNB) LTMs for SCG PSCell changes. The MN is responsible for coordinating the configuration of candidate PSCells across different CUs.

[0156] In some embodiments, the LTM is configured as follows:

[0157] In Rel-18, LTM uses LTM-Config to configure LTM configuration information.

[0158] The LTM configuration information may include, but is not limited to, one or more of the following:

[0159] LTM reference configuration;

[0160] One or more candidate cell configurations (using ltm-CandidateToReleaseList and ltm-CandidateToAddModList to add, modify, or delete candidate cell configurations);

[0161] LTM CSI (Channel State Information, CSI) resource configuration;

[0162] ·wait.

[0163] The candidate cell configuration can be configured through LTM-Candidate, which includes but is not limited to one or more of the following information:

[0164] Candidate configuration identification;

[0165] Candidate cell identifier;

[0166] Candidate configuration (expressed via RRCReconfiguration);

[0167] ·wait.

[0168] In some embodiments, the LTM candidate configuration is the configuration portion of an RRCReconfiguration message associated with a candidate cell, for example, for LTM or subsequent CPAC. The candidate configuration can be a complete candidate configuration or an incremental configuration relative to a reference configuration.

[0169] In some embodiments, the LTM reference configuration is a configuration provided by the network to the UE, which is a common configuration of a group of configured incomplete candidate configurations within the same cell group.

[0170] In some embodiments, R18 LTM only supports intra-DU and inter-DU intra-CU LTM. In R19 LTM, RAN 2 determines that the following scenarios are supported:

[0171] Scenario 1: When no DC is configured, the CU acts as the MN.

[0172] Scenario 2: When configuring NR-DC, the CU serves as the SN and the MCG remains unchanged.

[0173] Scenario 3: When NR-DC is configured, the CU acts as the MN, and the SCG remains unchanged or is released.

[0174] In some embodiments, referring to FIG. 1E , the MN's Key is updated during the handover process as follows:

[0175] In some embodiments, in an Xn handover, the source gNB / ng eNB shall perform vertical key derivation if it has an unused {NH, NCC} pair. NH stands for the Next Hop parameter. As described in A.11 / A.12, the source gNB / ng eNB shall first calculate KNG-RAN* based on the target PCI (PCI stands for Physical Cell Identifier), its frequency ARFCN-DL / EARFCN-DL, and the currently active KgNB in ​​the case of horizontal key derivation, or based on NH in the case of vertical key derivation. ARFCN stands for Absolute Radio-Frequency Channel Number. EARFCN stands for E-UTRA Absolute Radio Frequency Channel Number.

[0176] In some embodiments, the source gNB / ng eNB shall then forward the {KNG-RAN*, NCC} pair to the target gNB / ng eNB. The target gNB / ng eNB shall directly use the received KNG-RAN* as the KgNB to be used with the UE. The target gNB / ng eNB shall associate the NCC value received from the source gNB / ng eNB with the KgNB. The target gNB / ng eNB shall include the received NCC in a Prepared Hand Over (HO) Command message, which is sent back to the source gNB / ng eNB in ​​a transparent container and forwarded by the source gNB / ng eNB to the UE.

[0177] In some embodiments, the UE behavior is the same regardless of whether the handover is intra-gNB-CU, intra-ng-eNB, Xn, or N2 (Interface between RAN nodes), except that during intra-gNB-CU handover, the UE may retain the same keys based on instructions from the gNB. In the case of conditional handover, the UE behavior is also the same, as described in TS 38.300

[0052] , i.e., the UE shall use the parameters of the selected target cell in the KNG-RAN* derivation.

[0178] In some embodiments, if the NCC value received by the UE from the target ng eNB / g NB via the source ng eNB / gNB in ​​the HO Command message is equal to the NCC value associated with the currently active KgNB / KeNB, the UE shall derive KNG-RAN* from the currently activated KgNB / KeNB and the target PCI and its frequency ARFCN-DL / EARFCN-DL using the functions defined in A.11 and A.12.

[0179] In some embodiments, if the UE receives an NCC value that is different from the NCC associated with the currently active KgNB / KeNB, the UE shall first synchronize the locally maintained NH parameters by iteratively calculating the function defined in A.10 (and increasing the NCC value until it matches the NCC value received from the source ng eNB / gNB via the HO Command message. When the NCC values ​​match, the UE shall calculate KNG-RAN* based on the synchronized NH parameters and the target PCI and its frequency ARFCN-DL / EARFCN-DL using the function defined in A.11 / A.12.

[0180] In some embodiments, the UE shall use KNG-RAN* as KgNB when communicating with the target gNB and use KeNB when communicating with the target ng eNB.

[0181] In some embodiments, A.10 is an NH derivation function comprising:

[0182] When deriving NH from KAMF, the following parameters should be used to form the input S of the KDF:

[0183] -FC=0x6F;

[0184] -P0=SYNC-input;

[0185] -L0=length of SYNC-input (ie0x00 0x20).

[0186] In some embodiments, the input parameter of the SYNC parameter should be the newly derived KgNB for the initial NH derivation and the previous NH for all subsequent derivations. This forms an NH chain where the next NH is always new and derived from the previous NH.

[0187] In some embodiments, the input key KEY should be 256-bit KAMF.

[0188] In some embodiments, A.11 is a KNG-RAN* derivation function for the target gNB, comprising:

[0189] When deriving the KNG-RAN* from the current KgNB or from a new NH and target physical cell ID in the UE and NG-RAN for handover purposes and transition from RRC_INACTIVE to RRC_CONNECTED state, the following parameters shall be used to form the input S to the KDF:

[0190] FC=0x70

[0191] -P0=PCI(target physical cell id);

[0192] -L0=length of PCI(ie0x00 0x02);

[0193] -P1=ARFCN-DL(the absolute frequency of SSB of the target PCell as specified in clause 13.3 of TS 38.300

[0052] );

[0194] -L1=length of ARFCN-DL (ie0x00 0x03).

[0195] In some embodiments, when the index NCC in the handover increases, the input key KEY should be 256-bit NH, otherwise it should be the current 256-bit KgNB (when the source is gNB) or KeNB (when the source is ng-eNB).

[0196] In some embodiments, the implementation of the UE receiving the RRCReconfiguration includes:

[0197] The UE shall perform the following actions when receiving RRCReconfiguration, performing conditional reconfiguration (CHO, CPA or CPC) or performing LTM cell handover:

[0198] 1> If RRCReconfiguration includes masterKeyUpdate:

[0199] 2> Execute the AS security key update procedure specified in 5.3.5.7;

[0200] …

[0201] In some embodiments, implementation of AS security key update includes:

[0202] The UE shall:

[0203] 1> If the UE is connected to E-UTRA / EPC or E-UTRA / 5GC:

[0204] 2> Upon receiving the sk-Counter specified in TS 36.331

[0010] :

[0205] 3> Update the S-KgNB key based on the KeNB key and using the received sk-Counter value as specified in TS 33.401

[0030] for EN-DC or TS 33.501

[0011] for NGEN-DC;

[0206] 3> Generate KRRCenc and KUPenc keys according to TS 33.401

[0030] of EN-DC or TS 33.501

[0011] of NGEN-DC;

[0207] 3> Derive the KRRCint and KUPint keys as specified in TS 33.401

[0030] for EN-DC or TS 33.501

[0011] for NGEN-DC.

[0208] 1> Otherwise, if the program was started due to receiving a masterKeyUpdate:

[0209] 2> If the received masterKeyUpdate contains nas-Container:

[0210] 3>Forward the nas-Container to the upper layer;

[0211] 2>If keySetChangeIndicator is set to true:

[0212] 3> Generate or update KgNB keys based on KAMF keys in accordance with TS 33.501

[0011] ;

[0213] 2> Otherwise:

[0214] 3> Generate or update the KgNB key based on the current KgNB key or NH using the nextHopChainingCount value indicated in the received masterKeyUpdate, as specified in TS 33.501

[0011] ;

[0215] 2>Store nextHopChainingCount value;

[0216] 2>Export the keys related to KgNB keys as follows:

[0217] 3>If lgorithmConfig is included in SecurityConfig:

[0218] 4> Generate the KRRCenc and KUPenc keys associated with the encryption algorithm indicated in the securityAlgorithmConfig as specified in TS 33.501

[0011] ;

[0219] 4> Generate the KRRCint and KUPint keys associated with the integrityProtAlgorithm indicated in the security algorithm configuration as specified in TS 33.501

[0011] ;

[0220] 3> Otherwise:

[0221] 4> Generate the KRRCenc and KUPenc keys associated with the current encryption algorithm as specified in TS 33.501

[0011] ;

[0222] 4> According to the provisions of TS 33.501

[0011] , derive the KRRCint and KUPint keys associated with the current integrityProtAlgorithm.

[0223] Note 1: Encryption and integrity protection of DRB are optional.

[0224] 1> Otherwise, if the procedure was initiated due to reception of sk-Counter (UE is in NE-DC or NR-DC, or SN terminated bearer is configured), or if the procedure was initiated due to selection of sk-Counter for subsequent conditional reconfiguration of CPAC (UE is in NR-DC):

[0225] 2> Generate or update the secondary key (S-KgNB or S-KeNB) based on the KgNB key and using the received or selected sk-Counter value in accordance with TS 33.501

[0011] ;

[0226] 2> Generate the KRRCenc key and KUPenc key specified in TS 33.501

[0011] using the encryption algorithm indicated in RadioBearerConfig associated with the secondary key (S-KgNB or S-KeNB) indicated by keyToUse;

[0227] 2> Use the integrity protection algorithm indicated in RadioBearerConfig associated with the secondary key (S-KgNB or S-KeNB) indicated by keyToUse to derive the KRRCint key and KUPint key specified in TS 33.501

[0011] ;

[0228] NOTE 2: If the UE does not have a configured radio bearer with keyToUse set to secondary and receives sk-Counter without any RadioBearerConfig and with keyToUse set to secondary, the UE shall not consider it as an invalid reconfiguration.

[0229] In some embodiments, the Master Key change configuration is shown in FIG1F .

[0230] In some embodiments, the key set change indication (keySetChangeIndicator) indicates whether the UE should generate a new KgNB. If reconfigurationWithSync is included, a value of true indicates that the KgNB key is derived from the KAMF key used by the most recently successful NAS SMC procedure or N2 handover procedure, such as the KgNB rekey described in TS 33.501

[0011] . A value of false indicates that the new KgNB key is derived from the current KgNB key or NH described in TS 33.501

[0011] .

[0231] In some embodiments, the nextHopChainingCount parameter NCC: See TS33.501

[0011] , conditionally present: MasterKeyChange. If the masterCellGroup includes ReconfigurationWithSync (with synchronous reconfiguration) and the RadioBearerConfig includes SecurityConfig (with SecurityAlgorithmConfig), then this field must be present to indicate that the AS security algorithm associated with the master key has changed. If ReconfigurationWithSync is part of the LTM-Candidate IE associated with the MCG, then this field is not present. Otherwise, this field is not present.

[0232] In some embodiments, to support inter-gNB LTM, the UE may perform a rekey based on pre-configured rekey configuration. In existing mobility procedures, rekeying is only required for inter-gNB mobility. For handovers within the same node, the source gNB can continue to be used. However, because LTM is configured for each candidate cell, the LTM configuration does not include candidate gNB information. Therefore, the UE cannot determine the candidate gNB corresponding to each candidate cell. Therefore, the UE is unaware of inter-gNB handovers when performing LTM.

[0233] In some embodiments, considering that inter-gNB Conditional LTM may be supported in the future, since Conditional LTM is triggered based on conditions pre-configured on the network side, the network side cannot know when the UE will trigger LTM, and thus cannot directly instruct the UE whether it needs to perform a key update when executing LTM.

[0234] In view of this, embodiments of the present disclosure provide a communication method, terminal, communication system, and storage medium. This communication method can be used to indicate whether a key update is required when executing LTM. The UE determines whether a key update is required when executing LTM based on indication information from the network. The indication information can be directly indicated by the network or preconfigured by the network to the UE. The UE determines whether a key update is required when executing LTM based on predefined criteria.

[0235] FIG2A is an interactive diagram of a communication method according to an embodiment of the present disclosure. As shown in FIG2A , the embodiment of the present disclosure relates to a communication method, and the method includes:

[0236] Step S2101 : The network device 102 configures first information for the terminal 101 .

[0237] In some embodiments, the terminal 101 is configured with the first information. Optionally, the first information on the terminal 101 comes from the network device 102. Optionally, the first information on the terminal 101 is configured by the network device 102.

[0238] In some embodiments, the first information is used by the terminal to determine whether to perform a key update. For example, the terminal determines whether to perform a key update according to the first information in response to triggering / performing a mobility operation.

[0239] In some embodiments, the first information is used to indicate a first identifier associated with the terminal's serving cell and / or a second identifier associated with the first cell the terminal will access. For example, the first information includes the first identifier and / or the second identifier. Optionally, the first cell may be a cell indicated by a handover command. Optionally, the first cell may be a cell selected by the terminal based on relevant conditions. Optionally, the first cell may be a candidate cell or a candidate target cell. This disclosure does not limit the method for determining the first cell.

[0240] In some embodiments, the name of the first information is not limited, and it can be, for example, auxiliary information, reference information, identification information, key update configuration, pre-configuration information, etc.

[0241] In some embodiments, the network device configures the first information for the terminal in an implementation manner including: the network device may directly send the first information to the terminal, the first information including the first identifier and / or the second identifier. Optionally, the terminal receives the first information and obtains the first identifier and / or the second identifier.

[0242] In some embodiments, the network device may configure the first information for the terminal by configuring the first information for the terminal through relevant configuration. For example, the network device may pre-configure the first information for the terminal through relevant configuration.

[0243] The relevant configuration may be an LTM configuration. It should be noted that, when performing LTM configuration, the first identifier corresponding to the current serving cell of the terminal may be included in the LTM configuration (LTM-Config), and the identifier corresponding to the candidate cell may be included in the configuration of the LTM candidate cell (LTM-Candidate). LTM-Candidate may be configured according to LTM-Config. Therefore, in some embodiments, the network device may send a first configuration to the terminal. The first configuration is an LTM configuration, and the first configuration includes a first identifier. Optionally, the terminal receives the first configuration and stores the first identifier in a first variable. Optionally, the first variable is used to store an identifier associated with the serving cell of the terminal. Optionally, the name of the first variable is not limited, and it may be, for example, the first UE variable on the terminal. For example, the first variable is VarLTM-ServingSecurityCellSetID.

[0244] In some embodiments, a second variable is provided on the terminal. Optionally, a second configuration is stored in the second variable. Optionally, the second configuration is an LTM candidate cell configuration, with each second configuration corresponding to a candidate cell. Optionally, each second configuration includes an identifier of the corresponding candidate cell. Optionally, the network device may configure the second configuration for the terminal through LTM configuration. Optionally, the name of the second variable is not limited, and may be, for example, a second UE variable. For example, the second variable is VarLTM-Config.

[0245] It should be noted that when the terminal performs a mobility operation, the first cell to be accessed is one of the candidate cells. Accordingly, the second identifier of the first cell to be accessed by the terminal is the identifier in the second configuration corresponding to the first cell. In some embodiments, the name of the first cell is not limited, and it is, for example, the target handover cell.

[0246] In some embodiments, the first configuration includes specific information for configuring the cell after configuration. Optionally, the terminal receives the first configuration and updates at least one second configuration in the second variable according to the specific information.

[0247] In step S2102 , in response to executing the mobility operation, the terminal 101 determines whether to perform a key update according to the first information.

[0248] In some embodiments, the mobility operation includes LTM cell handover and / or CHO, wherein CHO includes but is not limited to subsequent CHO.

[0249] In some embodiments, the mobility operation may be any one or more of the following:

[0250] LTM for PCell / MCG changes;

[0251] LTM for PSCell / SCG changes;

[0252] LTM for PSCell / SCG addition;

[0253] CHO;

[0254] CPAC;

[0255] SubsequentCHO;

[0256] Subsequent CPAC.

[0257] In some embodiments, the execution of the mobility operation may be triggered by an indication from a network device and / or a detection that a condition for executing the mobility operation is met.

[0258] For example, the first identifier and the second identifier in the embodiments of the present disclosure may be cell set identifiers, i.e., cells with the same identifier belong to the same cell set, and cells in the same cell set correspond to the same access network device, such as a gNB. Mobility between cells in the same cell set does not require a key update. However, mobility between cells in different cell sets requires a key update. Similarly, the first identifier and the second identifier in the embodiments of the present disclosure may also be access network device identifiers, access network node identifiers, etc.

[0259] In some embodiments, the implementation of determining whether to perform a key update based on the first information includes: the terminal determining that a key update is required based on the difference between the first identifier and the second identifier.

[0260] In some embodiments, the implementation of determining whether to perform a key update based on the first information includes: the terminal determining not to perform a key update based on the first identifier being the same as the second identifier.

[0261] In some embodiments, determining whether to perform a key update based on the first information includes: the terminal determining to perform a key update based on the first information not including the first identifier. For example, the terminal may determine that a key update is required based on the first information not including the first identifier. For example, the terminal may determine that a key update is required based on the first information not including the first identifier and the first information including the second identifier.

[0262] In some embodiments, determining whether to perform a key update based on the first information includes: the terminal determining not to perform a key update based on the first information not including the first identifier. For example, the terminal may determine that a key update is not required based on the first information not including the first identifier. For example, the terminal may determine that a key update is not required based on the first information not including the first identifier and the first information including the second identifier.

[0263] In some embodiments, determining whether to perform a key update based on the first information includes: the terminal determining that a key update is required based on the first information not including the second identifier. For example, the terminal may determine that a key update is required based on the first information not including the second identifier. For example, the terminal may determine that a key update is required based on the first information including the second identifier and the first information not including the second identifier.

[0264] In some embodiments, determining whether to perform a key update based on the first information includes: the terminal determining not to perform a key update based on the first information not including the second identifier. For example, the terminal may determine that a key update is not required based on the first information not including the second identifier. For example, the terminal may determine that a key update is not required based on the first information including the second identifier and the first information not including the second identifier.

[0265] In some embodiments, if it is determined not to perform key update, the UE continues to use the original key.

[0266] In some embodiments, if it is determined to perform a key update, step S2103 is executed.

[0267] Step S2103: Terminal 101 performs key update according to key update related information associated with the second identifier.

[0268] In some embodiments, one or more key update related information is configured on the terminal. One key update related information is associated with an identifier, which is represented as an Index, for example.

[0269] In some embodiments, a network device may configure one or more key update-related information for a terminal through an LTM configuration. For example, the network device sends the LTM configuration to the terminal. The terminal receives the LTM configuration and stores at least one key update-related information based on the LTM configuration. For example, the terminal may store n key update-related information as shown in Table 1 below.

[0270] Table 1

[0271] In some embodiments, the network device may add, update, or remove key update related information on the terminal through a third configuration. Optionally, the third configuration may include any one or more of adding a modification table, deleting a table, adding a table, and modifying a table.

[0272] In some embodiments, the key update related information includes one or more NCCs. Optionally, the implementation of performing key update according to the key update related information associated with the second identifier includes: performing key update according to one NCC in the key update related information associated with the second identifier.

[0273] For example, a first NCC is determined from key update-related information associated with the second identifier. If the first NCC is the same as the second NCC (the second NCC is the NCC associated with the currently activated key, and the currently activated key is used for the current serving cell), a first key is generated according to a horizontal key derivation method. For example, the first key is generated based on the terminal's currently activated key, the identifier of the first cell, and the frequency information of the first cell. The generated first key is used as the key activated by the terminal after accessing the first cell.

[0274] For example, a first NCC is determined from key update-related information associated with the second identifier. If the first NCC is different from the second NCC, a first key is generated using a vertical key derivation method. For example, a first next hop parameter (NH) corresponding to the first NCC is determined. A first key is generated based on the first NH, the identifier of the first cell, and the frequency information of the first cell. The generated first key is used as the key activated by the terminal after accessing the first cell.

[0275] In some embodiments, the implementation of determining the first NCC from the key update related information associated with the second identifier may be to determine the first unused NCC in the key update related information associated with the second identifier as the first NCC.

[0276] In some embodiments, determining the first NCC from the key update related information associated with the second identifier may be implemented by determining a candidate NCC sequence corresponding to the first cell from the key update related information associated with the second identifier, and determining a first unused NCC in the candidate NCC sequence as the first NCC. The key update related information includes multiple candidate NCC sequences, and each candidate NCC sequence corresponds to one gNB, one cell set, or one cell.

[0277] The present disclosure does not limit the implementation of how to determine the first NCC from the key update related information associated with the second identifier.

[0278] The present disclosure does not limit the implementation method of how to perform key update based on the key update related information associated with the second identifier.

[0279] Step S2104: Update the first variable according to the second identifier.

[0280] In some embodiments, in response to the terminal performing a key update, the terminal updates the first variable according to the second identifier.

[0281] Exemplarily, when the terminal performs a key update, the first cell is the current serving cell of the terminal, and the updated activation key corresponds to the first cell, so the first variable is updated according to the second identifier of the first cell.

[0282] In some embodiments, when the terminal successfully accesses the first cell, the terminal updates the first variable according to the second identifier.

[0283] Exemplarily, when the terminal successfully accesses the first cell, the first cell is the current serving cell of the terminal. Accordingly, the first variable is updated according to the second identifier of the first cell.

[0284] In some embodiments, the names of information, etc. are not limited to the names described in the embodiments, and terms such as "information", "message", "signal", "signaling", "report", "configuration", "indication", "instruction", "command", "channel", "parameter", "domain", "field", "symbol", "symbol", "codeword", "codebook", "codeword", "codepoint", "bit", "data", "program", and "chip" can be used interchangeably.

[0285] In some embodiments, "obtain", "get", "get", "receive", "transmit", "bidirectional transmission", "send and / or receive" can be interchangeable, and can be interpreted as receiving from other entities, obtaining from protocols, obtaining from higher layers, obtaining by self-processing, autonomous implementation, etc.

[0286] In some embodiments, terms such as "send", "transmit", "report", "download", "transmit", "bidirectional transmission", "send and / or receive" can be used interchangeably.

[0287] In some embodiments, terms such as "certain", "preset", "preset", "setting", "indicated", "a certain", "any", and "first" can be interchangeable. "Specific A", "preset A", "preset A", "setting A", "indicated A", "a certain A", "any A", and "first A" can be interpreted as A pre-specified in a protocol, etc., or as A obtained through setting, configuration, or indication, etc., or as specific A, a certain A, any A, or first A, etc., but not limited to this.

[0288] In some embodiments, the determination or judgment can be performed by a value represented by 1 bit (0 or 1), or by a true or false value (Boolean value) represented by true or false, or by comparison of numerical values ​​(for example, comparison with a predetermined value), but is not limited thereto.

[0289] In some embodiments, “not performing key update” can be interpreted as not performing key update on time domain resources and / or frequency domain resources, and can also be interpreted as not executing the key update procedure, not responding to the key update operation, etc.

[0290] The communication method involved in the embodiment of the present disclosure may include at least one of steps S2101 to S2104. For example, step S2101 may be implemented as an independent embodiment, step S2102 may be implemented as an independent embodiment, and step S2103 may be implemented as an independent embodiment, but are not limited thereto.

[0291] In some embodiments, any two steps in steps S2101 to S2104 can be executed in an interchangeable order or simultaneously.

[0292] In some embodiments, steps S2101 to S2104 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0293] In some embodiments, reference may be made to other optional implementations described before or after the description corresponding to FIG. 2A .

[0294] FIG2B is an interactive diagram of a communication method according to an embodiment of the present disclosure. As shown in FIG2B , the embodiment of the present disclosure relates to a communication method, and the method includes:

[0295] Step S2201: The network device 102 sends second information to the terminal 101.

[0296] In some embodiments, terminal 101 receives second information.

[0297] In some embodiments, the second information is used by the terminal to determine whether to perform a key update when executing / responding to a mobility operation. Optionally, the mobility operation includes LTM cell handover and / or CHO. CHO includes but is not limited to subsequent CHO.

[0298] In some embodiments, the name of the second information is not limited, and it can be, for example, auxiliary information, reference information, key update configuration, instruction, indication, etc.

[0299] Optionally, the second information may be replaced with the first information in Figure 2A. For example, the second information indicates the first identifier and / or the second identifier.

[0300] In some embodiments, the network device sends the second information to the terminal via at least one of downlink control information DCI, a media access control layer MAC message, and a radio resource control RRC message.

[0301] In step S2202 , in response to executing the mobility operation, the terminal 101 determines whether to perform a key update according to the second information.

[0302] In some embodiments, the implementation method of the terminal determining whether to perform key update according to the second information includes: the terminal determining whether to perform key update according to content indicated by the received second information.

[0303] Optionally, if the second information indicates to update the key, the terminal performs the key update. Optionally, if the second information indicates not to update the key, the terminal does not perform the key update.

[0304] Optionally, if the second information indicates a first cell list, and the first cell list is used to instruct the terminal to perform a key update when accessing a cell in the first cell list, the terminal determines to perform a key update if it determines that the first cell list includes the first cell that the terminal will access. Alternatively, if it determines that the first cell list does not include the first cell, the terminal determines not to perform a key update. It should be noted that the present disclosure does not limit the name of the first cell list, and it can be, for example, a list of cells requiring key update, a specific list, etc.

[0305] Optionally, if the second information indicates a second cell list, and the second cell list is used to instruct the terminal not to perform a key update when accessing a cell in the second cell list, the terminal determines not to perform a key update upon determining that the second cell list includes the first cell to be accessed by the terminal; or, upon determining that the second cell list does not include the first cell, the terminal determines to perform a key update. It should be noted that the present disclosure does not limit the name of the second cell list, and it may, for example, be a list of cells that do not require a key update.

[0306] In some embodiments, the second information is sent by the network device to the terminal when the terminal accesses a current serving cell.

[0307] In some embodiments, step S2202 may be replaced by the terminal determining whether to perform a key update based on whether the second information is received at a specified timing. For example, if the terminal receives the second information before or simultaneously with receiving the LTM cell handover command, then the terminal determines to perform a key update. For example, if the terminal does not receive the second information before or simultaneously with receiving the LTM cell handover command, that is, if the terminal does not receive the second information before or simultaneously with receiving the LTM cell handover command, then the terminal does not perform a key update.

[0308] Optionally, the second information may be explicit indication information. For example, the network device sends an LTM cell switch command (LTM Cell Switch Command) to the UE, which includes explicit indication information instructing the UE to perform a key update. The terminal may determine that a key update is required based on the explicit indication information.

[0309] Optionally, the second information may be implicit indication information. For example, the network device sends an LTM Cell Switch Command to the UE, which includes relevant information required for key update, implicitly indicating the terminal to perform key update. The terminal may determine to perform key update based on the implicit indication information.

[0310] In some embodiments, in the case of the first identifier and / or the second identifier of the second information packet, the implementation of step S2202 can refer to the implementation of step S2102 in Figure 2A, and other related parts in the embodiment involved in Figure 2A, such as the relevant implementation parts of step S2103 and step S2101, which will not be repeated here.

[0311] In some embodiments, the names of information, etc. are not limited to the names described in the embodiments, and terms such as "information", "message", "signal", "signaling", "report", "configuration", "indication", "instruction", "command", "channel", "parameter", "domain", "field", "symbol", "symbol", "codeword", "codebook", "codeword", "codepoint", "bit", "data", "program", and "chip" can be used interchangeably.

[0312] In some embodiments, "obtain", "get", "get", "receive", "transmit", "bidirectional transmission", "send and / or receive" can be interchangeable, and can be interpreted as receiving from other entities, obtaining from protocols, obtaining from higher layers, obtaining by self-processing, autonomous implementation, etc.

[0313] In some embodiments, terms such as "send", "transmit", "report", "download", "transmit", "bidirectional transmission", "send and / or receive" can be used interchangeably.

[0314] In some embodiments, terms such as "certain", "preset", "preset", "setting", "indicated", "a certain", "any", and "first" can be interchangeable. "Specific A", "preset A", "preset A", "setting A", "indicated A", "a certain A", "any A", and "first A" can be interpreted as A pre-specified in a protocol, etc., or as A obtained through setting, configuration, or indication, etc., or as specific A, a certain A, any A, or first A, etc., but not limited to this.

[0315] In some embodiments, the determination or judgment can be performed by a value represented by 1 bit (0 or 1), or by a true or false value (Boolean value) represented by true or false, or by comparison of numerical values ​​(for example, comparison with a predetermined value), but is not limited thereto.

[0316] In some embodiments, “not performing key update” can be interpreted as not performing key update on time domain resources and / or frequency domain resources, and can also be interpreted as not executing the key update procedure, not responding to the key update operation, etc.

[0317] The communication method involved in the embodiment of the present disclosure may include at least one of step S2201 and step S2202. For example, step S2202 may be implemented as an independent embodiment, but is not limited thereto.

[0318] In some embodiments, step S2201 and step S2202 may be executed in an interchanged order or simultaneously.

[0319] In some embodiments, step S2201 and step S2202 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0320] In some embodiments, reference may be made to other optional implementations described before or after the description corresponding to FIG. 2B .

[0321] FIG3A is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG3A , the present disclosure embodiment relates to a communication method, which is executed by the terminal side, and the method includes:

[0322] Step S3101, receiving first information.

[0323] The optional implementation of step S3101 can refer to the optional implementation of step S2101 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0324] In some embodiments, the terminal 101 receives the first information sent by the network device 102, but is not limited thereto and may also receive the first information sent by other entities.

[0325] In some embodiments, terminal 101 obtains first information specified by a protocol.

[0326] In some embodiments, terminal 101 obtains the first information from upper layer(s).

[0327] In some embodiments, the terminal 101 performs processing to obtain the first information.

[0328] In some embodiments, step S3101 is omitted, and the terminal 101 autonomously implements the function indicated by the first information, or the above function is default or by default.

[0329] Step S3102: In response to executing the mobility operation, determining to perform a key update according to the first information.

[0330] The optional implementation of step S3102 can refer to the optional implementation of step S2102 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0331] Step S3103: performing key update according to key update related information associated with the second identifier.

[0332] The optional implementation of step S3103 can refer to the optional implementation of step S2103 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0333] Step S3104: When access to the first cell is successful, update the first variable according to the second identifier.

[0334] The optional implementation of step S3104 can refer to the optional implementation of step S2104 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0335] The communication method involved in the embodiment of the present disclosure may include at least one of steps S3101 to S3104. For example, step S3102 may be implemented as an independent embodiment, step S3103 may be implemented as an independent embodiment, and step S3104 may be implemented as an independent embodiment, but are not limited thereto.

[0336] In some embodiments, any two steps in step S3101 to step S3104 can be swapped in order or executed simultaneously.

[0337] In some embodiments, steps S3101 to S3104 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0338] FIG3B is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG3B , the present disclosure embodiment relates to a communication method, which is executed by the terminal side, and the method includes:

[0339] Step S3201: Receive a first configuration, where the first configuration is used to configure first information for a terminal.

[0340] The optional implementation of step S3201 can refer to the optional implementation of step S2101 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0341] In some embodiments, the terminal 101 receives the first configuration sent by the network device 102, but is not limited thereto and may also receive the first configuration sent by other entities.

[0342] In some embodiments, terminal 101 obtains a first configuration specified by a protocol.

[0343] In some embodiments, terminal 101 obtains the first configuration from upper layer(s).

[0344] In some embodiments, terminal 101 performs processing to obtain the first configuration.

[0345] In some embodiments, step S3201 is omitted, and the terminal 101 autonomously implements the function indicated by the first configuration, or the above function is default or by default.

[0346] Step S3202: In response to performing a mobility operation, determining to perform a key update according to the first information.

[0347] Optional implementations of step S3202 can be found in step S2102 of FIG. 2A , optional implementations of step S3102 of FIG. 3A , and other related parts of the embodiments involved in FIG. 2A and FIG. 3A , which will not be described in detail here.

[0348] Step S3203: performing key update according to key update related information associated with the second identifier.

[0349] Optional implementations of step S3203 may refer to step S2103 in FIG. 2A , optional implementations of step S3103 in FIG. 3A , and other related parts in the embodiments involved in FIG. 2A and FIG. 3A , which will not be described in detail here.

[0350] Step S3204: When access to the first cell is successful, update the first variable according to the second identifier.

[0351] Optional implementations of step S3204 may refer to step S2104 in FIG. 2A , optional implementations of step S3104 in FIG. 3A , and other related parts in the embodiments involved in FIG. 2A and FIG. 3A , which will not be described in detail here.

[0352] The communication method involved in the embodiment of the present disclosure may include at least one of steps S3201 to S3204. For example, step S3201 may be implemented as an independent embodiment, step S3202 may be implemented as an independent embodiment, and step S3203 may be implemented as an independent embodiment, but are not limited thereto.

[0353] In some embodiments, any two steps in step S3201 to step S3204 can be swapped in order or executed simultaneously.

[0354] In some embodiments, steps S3201 to S3204 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0355] FIG3C is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG3C , the present disclosure embodiment relates to a communication method, which is executed by the terminal side, and the method includes:

[0356] Step S3301: In response to executing a mobility operation, determining to perform a key update according to first information.

[0357] The optional implementation of step S3301 can refer to step S2102 in Figure 2A, the optional implementation of step S3102 in Figure 3A, and other related parts in the embodiments involved in Figures 2A and 3A, which will not be repeated here.

[0358] Step S3302: Perform key update according to key update related information associated with the second identifier.

[0359] The optional implementation of step S3302 can refer to the optional implementation of step S2103 in Figure 2A, step S3103 in Figure 3A, and other related parts in the embodiments involved in Figures 2A and 3A, which will not be repeated here.

[0360] Step S3303: When access to the first cell is successful, the first variable is updated according to the second identifier.

[0361] The optional implementation of step S3303 can refer to the optional implementation of step S2104 in Figure 2A, step S3104 in Figure 3A, and other related parts in the embodiments involved in Figures 2A and 3A, which will not be repeated here.

[0362] The communication method involved in the embodiment of the present disclosure may include at least one of steps S3301 to S3303. For example, step S3301 may be implemented as an independent embodiment, and step S3302 may be implemented as an independent embodiment, but is not limited thereto.

[0363] In some embodiments, steps S3301 to S3303 may be executed in an interchangeable order or simultaneously.

[0364] In some embodiments, steps S3301 to S3303 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0365] In some embodiments, step S3301 may be combined with step S3101 of Figure 3A. Step S3301 may be combined with step S3201 of Figure 3B.

[0366] FIG3D is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG3D , the present disclosure embodiment relates to a communication method, which is executed by the terminal side, and the method includes:

[0367] Step S3401: In response to performing a mobility operation, determining to perform a key update according to first information.

[0368] Optional implementations of step S3401 can be found in step S2102 of FIG. 2A , optional implementations of step S3102 of FIG. 3A , and other related parts in the embodiments involved in FIG. 2A and FIG. 3A , which will not be described in detail here.

[0369] Step S3402: When access to the first cell is successful, update the first variable according to the second identifier.

[0370] Optional implementations of step S3402 can be found in step S2104 of FIG. 2A , optional implementations of step S3104 of FIG. 3A , and other related parts of the embodiments involved in FIG. 2A and FIG. 3A , which will not be described in detail here.

[0371] The communication method involved in the embodiment of the present disclosure may include at least one of step S3401 and step S3402. For example, step S3401 may be implemented as an independent embodiment, and step S3402 may be implemented as an independent embodiment, but is not limited thereto.

[0372] In some embodiments, step S3401 and step S3402 may be performed in an interchangeable order or simultaneously.

[0373] In some embodiments, step S3401 and step S3402 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0374] In some embodiments, step S3401 may be combined with step S3101 or step S3103 of Figure 3A , step S3401 may be combined with step S3201 of Figure 3B , or step S3401 may be combined with step S3302 of Figure 3C .

[0375] FIG3E is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG3E , the present disclosure embodiment relates to a communication method, which is executed by the terminal side, and the method includes:

[0376] Step S3501: In response to executing a mobility operation, determining whether to perform a key update according to first information.

[0377] The optional implementation of step S3501 can refer to the optional implementation of step S2102 in Figure 2A, step S3102 in Figure 3A, and other related parts in the embodiments involved in Figures 2A and 3A, which will not be repeated here.

[0378] FIG3F is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG3F , the present disclosure embodiment relates to a communication method, which is executed by the terminal side, and the method includes:

[0379] Step S3601, receiving the second information.

[0380] The optional implementation of step S3601 can refer to the optional implementation of step S2201 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0381] In some embodiments, the terminal 101 receives the second information sent by the network device 102, but is not limited thereto and may also receive the second information sent by other entities.

[0382] In some embodiments, terminal 101 obtains second information specified by the protocol.

[0383] In some embodiments, terminal 101 obtains the second information from upper layer(s).

[0384] In some embodiments, terminal 101 performs processing to obtain the second information.

[0385] In some embodiments, step S3101 is omitted, and the terminal 101 autonomously implements the function indicated by the second information, or the above function is default or acquiescent.

[0386] Step S3602: If the second information indicates to update the key, the key is updated.

[0387] The optional implementation of step S3602 can refer to the optional implementation of step S2202 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0388] The communication method involved in the embodiment of the present disclosure may include at least one of step S3601 and step S3602. For example, step S3601 may be implemented as an independent embodiment, and step S3602 may be implemented as an independent embodiment, but is not limited thereto.

[0389] In some embodiments, step S3601 and step S3602 may be performed in an interchangeable order or simultaneously.

[0390] In some embodiments, step S3601 and step S3602 are optional, and one or more of these steps may be omitted or replaced in different embodiments.

[0391] FIG3G is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG3G , the present disclosure embodiment relates to a communication method, which is executed by the terminal side, and the method includes:

[0392] Step S3701: before receiving the LTM cell switching command, the second information is received and the key is updated.

[0393] The optional implementation of step S3701 can refer to the optional implementation of step S2202 in Figure 2B, step S3601 in Figure 3F, and other related parts in the embodiments involved in Figures 2B and 3F, which will not be repeated here.

[0394] Figure 3H is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in Figure 3H, the embodiment of the present disclosure relates to a communication method, which is executed by the terminal side, and the method includes:

[0395] Step S3801: When the first cell list includes the first cell to be accessed by the terminal, it is determined to perform a key update.

[0396] The optional implementation of step S3801 can refer to the optional implementation of step S2202 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0397] FIG3I is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG3I , the embodiment of the present disclosure relates to a communication method, which is executed by the terminal side, and the method includes:

[0398] Step S3901: When the second cell list does not include the first cell to be accessed by the terminal, it is determined to perform a key update.

[0399] The optional implementation of step S3901 can refer to the optional implementation of step S2202 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0400] FIG3J is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG3J , the embodiment of the present disclosure relates to a communication method, which is executed by the terminal side. The method includes:

[0401] Step S31001: Perform mobility operations to determine whether to perform key update.

[0402] The optional implementation of step S31001 can refer to the optional implementation of step S2102 in Figure 2A, step S2202 in Figure 2B, and other related parts in the embodiments involved in Figures 2A and 2B, which will not be repeated here.

[0403] Figure 3K is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in Figure 3K, the embodiment of the present disclosure relates to a communication method, which is executed by the terminal side, and the method includes:

[0404] Step S31101: perform key update according to key update related information.

[0405] The optional implementation of step S31101 can refer to the optional implementation of step S2103 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0406] Figure 3L is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in Figure 3L, the embodiment of the present disclosure relates to a communication method, which is executed by the terminal side, and the method includes:

[0407] Step S31201: Update the first variable according to the second identifier.

[0408] The optional implementation of step S31201 can refer to the optional implementation of step S2104 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0409] FIG4A is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG4A , the present disclosure embodiment relates to a communication method, which is executed by a network device side, and the method includes:

[0410] Step S4101: configure first information for the terminal.

[0411] The optional implementation of step S4101 can refer to the optional implementation of step S2101 in Figure 2A and other related parts in the embodiment involved in Figure 2A, which will not be repeated here.

[0412] FIG4B is a flow chart of a communication method according to an embodiment of the present disclosure. As shown in FIG4B , the present disclosure embodiment relates to a communication method, which is executed by a network device side, and the method includes:

[0413] Step S4201, sending the second information.

[0414] The optional implementation of step S4201 can refer to the optional implementation of step S2201 in Figure 2B and other related parts in the embodiment involved in Figure 2B, which will not be repeated here.

[0415] In some embodiments, in embodiment 1, whether a key update is required is determined through information pre-configured on the network side.

[0416] Optionally, the network configures an identifier for each candidate cell (or each candidate configuration) and the current serving cell. If the LTM target cell to be accessed and the current serving cell correspond to the same identifier, no key update is required. Otherwise, a key update is required. Optionally, cells with the same identifier are identified as cells in the same gNB.

[0417] Optionally, the network side can pre-configure the relevant information required for key update during the LTM process. When pre-configuring the key update related information, the network side can associate the above-mentioned identifier and the key update related information. Each time the UE accesses the LTM candidate cell corresponding to the corresponding identifier, the corresponding key update related information can be used to perform key update.

[0418] In some embodiments, embodiment 2, the UE is directly instructed via network signaling whether a key update is required when executing LTM.

[0419] Optionally, the network side may include indication information in the LTM switching command, where the indication information is used to indicate that the UE needs to perform a key update.

[0420] Optionally, the network side may indicate in advance through L1 / L2 / L3 signaling whether the UE needs to perform key update the next time LTM is executed, and then the network side sends a switching command to trigger LTM.

[0421] Optionally, the network side may inform the UE in advance which cells require key update when accessing and which cells do not require key update when accessing.

[0422] In some embodiments, in embodiment 1, whether a key update is required is determined through information pre-configured on the network side.

[0423] Optionally, the network configures an identifier for each candidate cell (or each candidate configuration) and the current serving cell. If the LTM target cell to be accessed and the current serving cell correspond to the same identifier, no key update is required. Otherwise, a key update is required. Optionally, cells with the same identifier are identified as cells in the same gNB.

[0424] In some embodiments, the network side sends one or more security identifiers to the UE. Each candidate cell and the current serving cell are associated with an identifier, and the identifier is used to indicate whether the UE needs to perform a key update when executing LTM.

[0425] In some embodiments, the identifier can be configured using information used for LTM configuration. When performing LTM configuration, the first identifier corresponding to the current serving cell can be included in the LTM configuration (LTM-Config), and the second identifier corresponding to the candidate cell can be included in the LTM candidate cell configuration (LTM-Candidate).

[0426] Exemplarily, the first identifier and the second identifier may be cell set identifiers. Cells with the same identifier belong to the same set, and cells in the same set are from the same gNB. Mobility between cells in the same set does not require key update.

[0427] Exemplarily, the first identification configuration code may be as shown in Figure 5A. Referring to Figure 5A, the first identification may be configured through servingSecurityCellSetId.

[0428] Optionally, each LTM-Candidate corresponds to a candidate cell and includes an LTM candidate identifier and a corresponding LTM candidate configuration (ltm-CandidateConfig). The second identifier is included in the LTM-Candidate, thereby associating a second identifier with a candidate cell (or LTM candidate configuration). For example, the second identifier configuration code is shown in FIG5B . Referring to FIG5B , the second identifier can be configured using securityCellSetId.

[0429] In some embodiments, when the UE receives the configuration of the LTM candidate cell carrying the second identifier, the UE stores the second identifier and the configuration of the LTM candidate cell together in a second UE variable (VarLTM-Config), and the second UE variable is used to store the LTM candidate configuration, etc.

[0430] In some embodiments, when the UE receives the first identifier, the UE stores the first identifier.

[0431] Optionally, the UE stores it in a first UE variable (e.g., VarLTM-ServingSecurityCellSetID), which is used to store the security identifier corresponding to the current serving cell. The UE variable VarLTM-ServingSecurityCellSetID includes the security cell setting ID of the serving PCell (or PSCell or sPCell) for LTM. For example, the configuration of VarLTM-ServingSecurityCellSetID can be as follows:

[0432] VarLTM-ServingSecurityCellSetID UE variable

[0433] Optionally, the UE may store the first identifier in a second UE variable, and store the first identifier through a specific first parameter, where the first UE parameter is used to store an identifier for security corresponding to the current serving cell.

[0434] In some embodiments, based on the above configuration, the UE determines whether a key update is required when performing LTM. For example, when the UE performs LTM, if the security identifier corresponding to the LTM target cell is different from the identifier corresponding to the current serving cell, the UE performs a key update.

[0435] Optionally, when the UE executes LTM, if the second identifier corresponding to the LTM target cell is not equal to the first identifier stored in the UE variable, the UE executes a key update.

[0436] In some embodiments, based on the above configuration, the UE determines whether a key update is required when performing LTM. For example, when the UE performs LTM, if the UE does not store the identifier corresponding to the current serving cell, the UE performs a key update.

[0437] Optionally, when the UE performs LTM, if the first identifier is not stored in the UE variable, the UE performs a key update.

[0438] In some embodiments, if the security identifier corresponding to the LTM target cell is the same as the identifier corresponding to the current serving cell, the UE continues to use the original key; if the current LTM target cell does not have a corresponding security identifier, the UE continues to use the original key.

[0439] In some embodiments, when the UE performs LTM to access the target cell and performs a key update, the UE needs to use the security identifier corresponding to the target cell to update the security identifier associated with the serving cell stored in the UE.

[0440] Optionally, when the UE executes LTM, if the second identifier corresponding to the LTM target cell (the selected cell to be accessed) is not equal to the first identifier stored in the UE variable, the value of the second identifier associated with the target cell is used to replace the value of the first identifier stored in the UE variable as the security identifier associated with the service cell.

[0441] Optionally, when the UE executes LTM, if the first identifier is not stored in the UE variable, the value of the second identifier associated with the target cell is stored in the UE variable as the value of the identifier for security associated with the serving cell, that is, the first identifier.

[0442] In some embodiments, the network side can pre-configure the relevant information required for key update during the LTM process. When pre-configuring the key update related information, the network side can associate the above-mentioned identifier and the key update related information. Each time the UE accesses the LTM candidate cell corresponding to the corresponding identifier, the corresponding key update related information can be used to perform key update.

[0443] In some embodiments, the network side sends one or more security identifiers to the UE, each security identifier can be associated with corresponding key update related information. When the UE accesses the LTM candidate cell corresponding to the identifier for key update, the corresponding key update related information is used to perform key update.

[0444] In some embodiments, the key update related information and its associated security identifier can be configured through LTM configuration (LTM-Config), which can configure one or more groups of key update related information through AddMod List and Remove List, each group of information is associated with an identifier.

[0445] In some embodiments, the UE may store one or more sets of key update-related information based on the received LTM configuration, where each set of information is associated with an identifier, as shown in Table 1 in the aforementioned embodiment.

[0446] In some embodiments, the network can implement the addition and update of key update-related information by including these identifiers and the key update-related information to be added or updated in an AddMod List; the network can implement the removal of key update-related information by including these identifiers in a Remove List. The UE updates the stored key update-related information n based on the received AddMod List and Remove List.

[0447] In some embodiments, the key update-related information may include one or more of the following information:

[0448] an NCC value;

[0449] A set of NCC value lists.

[0450] In some embodiments, embodiment 2, the UE is directly instructed via network signaling whether a key update is required when executing LTM.

[0451] In some embodiments, the network side sends an LTM Cell Switch Command to the UE, which includes indication information instructing the UE to perform key update. The indication information can be explicit indication information or implicit indication information, for example, including relevant information required for key update.

[0452] In some embodiments, after determining the LTM candidate cell, the network side may indicate to the UE through a first message that a key update is required when the next LTM is executed before sending a handover command to the UE.

[0453] Optionally, the first message may be any one or more of a DCI, a MAC CE, and an RRC message, and the indication information may be explicit indication information or implicit indication information, for example, including relevant information required for key update.

[0454] Optionally, when the UE receives the LTM Cell Switch Command, if the UE receives the first message, it performs a key update.

[0455] Optionally, when the UE receives the LTM Cell Switch Command, if it has not received the first message, it continues to use the original key

[0456] In some embodiments, after the UE executes LTM to access a new candidate cell, the network side can send a second message to the UE. Based on the candidate cell list (or LTM configuration list) in the second message, the UE can determine whether a key update is required when executing LTM next time.

[0457] Optionally, the second message may include a list of candidate cell identifiers (or LTM configuration identifier list) corresponding to the key update required by the UE. When the UE executes LTM, if the LTM candidate cell (or the corresponding configuration ID) belongs to the candidate cell identifier list (or LTM configuration identifier list), the key update is performed; otherwise, the original key continues to be used.

[0458] Optionally, the second message may include a list of candidate cell identifiers (or LTM configuration identifier list) corresponding to the original key that the UE needs to keep. When the UE executes LTM, if the LTM candidate cell (or the corresponding configuration ID) belongs to the candidate cell identifier list (or LTM configuration identifier list), the original key continues to be used, otherwise the key is updated.

[0459] Optionally, the first message may be any one or more of a DCI, a MAC CE, and an RRC message.

[0460] In the embodiments of the present disclosure, some or all of the steps and their optional implementations may be arbitrarily combined with some or all of the steps in other embodiments, or may be arbitrarily combined with the optional implementations of other embodiments.

[0461] The embodiments of the present disclosure further provide an apparatus for implementing any of the above methods. For example, an apparatus is provided, comprising units or modules for implementing each step performed by a terminal in any of the above methods. For another example, another apparatus is provided, comprising units or modules for implementing each step performed by a network device (e.g., an access network device, a core network function node, a core network device, etc.) in any of the above methods.

[0462] It should be understood that the division of the various units or modules in the above device is merely a division of logical functions. In actual implementation, they may be fully or partially integrated into a physical entity, or they may be physically separated. In addition, the units or modules in the device may be implemented in the form of a processor calling software: for example, the device includes a processor, the processor is connected to a memory, and the memory stores instructions. The processor calls the instructions stored in the memory to implement any of the above methods or implement the functions of the various units or modules of the above device, wherein the processor is, for example, a general-purpose processor, such as a central processing unit (CPU) or a microprocessor, and the memory is a memory within the device or a memory outside the device. Alternatively, the units or modules in the device can be implemented in the form of hardware circuits, and the functions of some or all of the units or modules can be realized by designing the hardware circuits. The above-mentioned hardware circuits can be understood as one or more processors; for example, in one implementation, the above-mentioned hardware circuit is an application-specific integrated circuit (ASIC), which realizes the functions of some or all of the above units or modules by designing the logical relationship of the components in the circuit; for example, in another implementation, the above-mentioned hardware circuit can be realized by a programmable logic device (PLD). Taking a field programmable gate array (FPGA) as an example, it can include a large number of logic gate circuits, and the connection relationship between the logic gate circuits is configured by configuring the configuration file, thereby realizing the functions of some or all of the above units or modules. All units or modules of the above devices can be realized in the form of software called by the processor, or in the form of hardware circuits, or in part by the form of software called by the processor, and the rest by hardware circuits.

[0463] In the embodiments of the present disclosure, the processor is a circuit with signal processing capabilities. In one implementation, the processor can be a circuit with instruction reading and execution capabilities, such as a central processing unit (CPU), a microprocessor, a graphics processing unit (GPU) (which can be understood as a microprocessor), or a digital signal processor (DSP). In another implementation, the processor can implement certain functions through the logical relationship of the hardware circuit. The logical relationship of the above-mentioned hardware circuit is fixed or reconfigurable. For example, the processor is a hardware circuit implemented by an application-specific integrated circuit (ASIC) or a programmable logic device (PLD), such as an FPGA. In a reconfigurable hardware circuit, the process of the processor loading a configuration document and implementing the hardware circuit configuration can be understood as the process of the processor loading instructions to implement the functions of some or all of the above units or modules. In addition, it can also be a hardware circuit designed for artificial intelligence, which can be understood as an ASIC, such as a neural network processing unit (NPU), a tensor processing unit (TPU), a deep learning processing unit (DPU), etc.

[0464] Figure 6A is a schematic diagram of the structure of the terminal proposed in an embodiment of the present disclosure. As shown in Figure 6A, the terminal 5100 may include: at least one of a transceiver module 5101, a processing module 5102, etc. In some embodiments, the processing module is used to perform mobility operations and determine whether to perform a key update. Optionally, the transceiver module is used to perform at least one of the communication steps such as sending and / or receiving (for example, step S2101, step S2201, but not limited to this) performed by the terminal 101 in any of the above methods, which will not be repeated here. Optionally, the processing module is used to perform at least one of the other steps (for example, steps S2102 to S2104, step S2202, but not limited to this) performed by the terminal 101 in any of the above methods, which will not be repeated here.

[0465] Figure 6B is a schematic diagram of the structure of the network device proposed in an embodiment of the present disclosure. As shown in Figure 6B, the network device 6100 may include: at least one of a transceiver module 6101, a processing module 6102, etc. In some embodiments, the above-mentioned transceiver module is used to instruct the terminal to perform a key update operation if it is determined that a key needs to be updated when a mobility operation is triggered. Optionally, the above-mentioned transceiver module is used to execute at least one of the communication steps such as sending and / or receiving (for example, step S2101, step S2201, but not limited to this) executed by the network device 102 in any of the above methods, which will not be repeated here. Optionally, the above-mentioned processing module is used to execute at least one of the other steps (for example, steps S2102 to S2104, step S2202, but not limited to this) executed by the network device 102 in any of the above methods, which will not be repeated here.

[0466] In some embodiments, the transceiver module may include a transmitting module and / or a receiving module, and the transmitting module and the receiving module may be separate or integrated. Optionally, the transceiver module may be interchangeable with the transceiver.

[0467] In some embodiments, the processing module can be a single module or can include multiple submodules. Optionally, the multiple submodules respectively execute all or part of the steps required to be executed by the processing module. Optionally, the processing module can be interchangeable with the processor.

[0468] Figure 7A is a schematic diagram of the structure of a communication device 8100 proposed in an embodiment of the present disclosure. Communication device 8100 can be a network device (e.g., an access network device, a core network device, etc.), a terminal (e.g., a user equipment, etc.), a chip, a chip system, or a processor that supports a network device to implement any of the above methods, or a chip, a chip system, or a processor that supports a terminal to implement any of the above methods. Communication device 8100 can be used to implement the methods described in the above method embodiments. For details, please refer to the description of the above method embodiments.

[0469] As shown in Figure 7A, the communication device 8100 includes one or more processors 8101. The processor 8101 can be a general-purpose processor or a dedicated processor, for example, a baseband processor or a central processing unit. The baseband processor can be used to process the communication protocol and communication data, and the central processing unit can be used to control the communication device (such as a base station, a baseband chip, a terminal device, a terminal device chip, a DU or a CU, etc.), execute programs, and process program data. Optionally, the communication device 8100 is used to perform any of the above methods. Optionally, one or more processors 8101 are used to call instructions to enable the communication device 8100 to perform any of the above methods.

[0470] In some embodiments, the communication device 8100 further includes one or more transceivers 8102. When the communication device 8100 includes one or more transceivers 8102, the transceiver 8102 performs at least one of the communication steps such as sending and / or receiving in the above method (for example, step S2101, step S2201, but not limited thereto), and the processor 8101 performs at least one of the other steps (for example, steps S2102 to S2104, step S2202, but not limited thereto). In an optional embodiment, the transceiver may include a receiver and / or a transmitter, and the receiver and transmitter may be separate or integrated together. Optionally, the terms transceiver, transceiver unit, transceiver, transceiver circuit, interface circuit, interface, etc. may be interchangeable, the terms transmitter, transmitting unit, transmitter, transmitting circuit, etc. may be interchangeable, and the terms receiver, receiving unit, receiver, receiving circuit, etc. may be interchangeable.

[0471] In some embodiments, the communication device 8100 also includes one or more memories 8103 for storing data. Alternatively, all or part of the memories 8103 may be located outside the communication device 8100. In alternative embodiments, the communication device 8100 may include one or more interface circuits 8104. Optionally, the interface circuits 8104 are connected to the transceiver 8102 and may be configured to receive data from the transceiver 8102 or other devices, or to transmit data to the transceiver 8102 or other devices. For example, the interface circuits 8104 may read data stored in the transceiver 8102 and transmit the data to the processor 8101.

[0472] The communication device 8100 described in the above embodiment may be a network device or a terminal, but the scope of the communication device 8100 described in the present disclosure is not limited thereto, and the structure of the communication device 8100 may not be limited by FIG. 7A. The communication device may be an independent device or may be part of a larger device. For example, the communication device may be: 1) an independent integrated circuit IC, or a chip, or a chip system or subsystem; (2) a collection of one or more ICs, optionally, the above IC collection may also include a storage component for storing data or programs; (3) an ASIC, such as a modem; (4) a module that can be embedded in other devices; (5) a receiver, a terminal device, an intelligent terminal device, a cellular phone, a wireless device, a handheld device, a mobile unit, an in-vehicle device, a network device, a cloud device, an artificial intelligence device, etc.; (6) others, etc.

[0473] 7B is a schematic diagram of the structure of the chip 8200 proposed in an embodiment of the present disclosure. If the communication device 8100 can be a chip or a chip system, please refer to the schematic diagram of the structure of the chip 8200 shown in FIG7B , but the present disclosure is not limited thereto.

[0474] The chip 8200 includes one or more processors 8201. The chip 8200 is configured to execute any of the above methods.

[0475] In some embodiments, chip 8200 further includes one or more interface circuits 8202. Terms such as interface circuit, interface, and transceiver pins may be used interchangeably. In some embodiments, chip 8200 further includes one or more memories 8203 for storing data. Alternatively, all or part of memory 8203 may be located external to chip 8200. Optionally, interface circuit 8202 is connected to memory 8203 and may be used to receive data from memory 8203 or other devices, or may be used to send data to memory 8203 or other devices. For example, interface circuit 8202 may read data stored in memory 8203 and send the data to processor 8201.

[0476] In some embodiments, the interface circuit 8202 performs at least one of the communication steps (e.g., step S2101 and step S2201, but not limited thereto) of the sending and / or receiving in the above method. The interface circuit 8202 performing the communication steps (e.g., step S2101 and step S2201, but not limited thereto) of the above method, for example, means that the interface circuit 8202 performs data exchange between the processor 8201, chip 8200, memory 8203, or transceiver device. In some embodiments, the processor 8201 performs at least one of the other steps (e.g., steps S2102 to S2104, step S2202, but not limited thereto).

[0477] The modules and / or devices described in various embodiments, such as virtual devices, physical devices, and chips, can be arbitrarily combined or separated according to circumstances. Optionally, some or all steps can also be performed collaboratively by multiple modules and / or devices, which is not limited here.

[0478] The present disclosure also proposes a storage medium having instructions stored thereon, which, when executed on the communication device 8100, causes the communication device 8100 to execute any of the above methods. Optionally, the storage medium is an electronic storage medium. Optionally, the storage medium is a computer-readable storage medium, but is not limited thereto, and may also be a storage medium readable by other devices. Optionally, the storage medium may be a non-transitory storage medium, but is not limited thereto, and may also be a temporary storage medium.

[0479] The present disclosure also provides a program product, which, when executed by the communication device 8100, enables the communication device 8100 to perform any of the above methods. Optionally, the program product is a computer program product.

[0480] The present disclosure also proposes a computer program, which, when executed on a computer, causes the computer to perform any one of the above methods.

Claims

1. A communication method, characterized in that: Executed by a terminal, the method includes: Perform mobility operations to determine whether to perform a key update.

2. The method according to claim 1, characterized in that The determining whether to perform a key update includes: Whether to perform key update is determined according to first information, where the first information includes a first identifier associated with a serving cell of the terminal and / or a second identifier associated with a first cell that the terminal will access.

3. The method according to claim 2, characterized in that The first information is configured by a network device for the terminal.

4. The method according to claim 2 or 3, characterized in that The determining whether to perform a key update according to the first information includes: The first identifier is different from the second identifier, and a key update is performed.

5. The method according to claim 2 or 3, characterized in that The determining whether to perform a key update according to the first information includes: The first identifier is the same as the second identifier, and no key update is performed.

6. The method according to claim 2 or 3, characterized in that The determining whether to perform a key update according to the first information includes: The first information does not include the first identifier, and a key update is performed.

7. The method according to claim 2 or 3, characterized in that The determining whether to perform a key update according to the first information includes: The first information does not include the second identifier, and the key update is not performed.

8. The method according to any one of claims 2 to 7, characterized in that The method further comprises: receiving a first configuration sent by a network device, where the first configuration includes the first identifier; The first identifier is stored in a first variable, and the first variable is used to store the serving cell of the terminal. The ID of the association.

9. The method according to claim 8, characterized in that The first configuration further includes specific information for post-configuration cell configuration, and the method further includes: At least one second configuration in the second variable is updated according to the specific information, one second configuration corresponds to one candidate cell, and the second configuration includes an identifier of the corresponding candidate cell.

10. The method according to claim 8 or 9, characterized in that The first configuration is an LTM configuration.

11. The method according to claim 9, characterized in that The second configuration is an LTM candidate cell configuration.

12. The method according to claim 4 or 6, characterized in that After the key update is performed, the following steps are included: The first cell is successfully accessed, and a first variable is updated according to the second identifier, where the first variable is used to store an identifier associated with a serving cell of the terminal.

13. The method according to claim 9, characterized in that One identifier is associated with one key update related information, and the key update includes: The key is updated according to the key update related information associated with the second identifier.

14. The method according to claim 13, characterized in that The key update related information includes one or more next hop chain counter parameters NCC; The performing key updating according to the key update related information associated with the second identifier includes: The key update is performed according to an NCC in the key update related information associated with the second identifier.

15. The method according to claim 13 or 14, characterized in that The method further comprises: At least one key update related information is stored according to the LTM configuration.

16. The method according to any one of claims 13 to 15, characterized in that The key update related information on the terminal is added, updated or removed by the network device through a third configuration.

17. The method according to claim 1, wherein The determining whether to perform a key update includes: receiving second information sent by the network device; Determine whether to perform key update according to the second information.

18. The method according to claim 17, characterized in that The determining whether to perform a key update according to the second information includes: The second information indicates that the key is updated, and the key update is performed; or the second information indicates that the key is not updated, and the key update is not performed.

19. The method according to claim 1, wherein The determining whether to perform a key update includes: If the second information is received before the LTM cell switching command is received, the key update is performed; or if the second information is not received before the LTM cell switching command is received, the key update is not performed.

20. The method according to claim 17, wherein The second information includes a first cell list, where the first cell list is used to instruct the terminal to perform a key update when accessing a cell in the first cell list; The determining whether to perform a key update according to the second information includes: The first cell list includes a first cell that the terminal will access and perform key update; Alternatively, the first cell list does not include the first cell and no key update is performed.

21. The method according to claim 17, wherein The second information includes a second cell list, where the second cell list is used to instruct the terminal not to perform a key update when accessing a cell in the second cell list; The determining whether to perform a key update according to the second information includes: The second cell list includes a first cell to be accessed by the terminal, and no key update is performed; Alternatively, the second cell list does not include the first cell, and a key update is performed.

22. The method according to claim 20 or 21, characterized in that The second information is sent by the network device to the terminal after the terminal accesses the current serving cell.

23. The method according to any one of claims 17 to 22, characterized in that The second information is sent by the network device through at least one of downlink control information DCI, a media access control layer MAC message, and a radio resource control RRC message.

24. The method according to any one of claims 1 to 23, characterized in that The mobility operation includes at least one of the following: Mobility LTM cell switching based on layer L1 / L2 triggering; Condition-based switching CHO.

25. A terminal, characterized in that: include: The processing module is used to perform mobility operations and determine whether to perform key update.

26. A terminal, characterized in that: include: one or more processors; A memory coupled to the processor, wherein the memory stores executable instructions, and when the executable instructions are executed by the processor, the terminal executes the communication method according to any one of claims 1 to 24.

27. A communication system, characterized in that: The invention comprises a terminal and a network device, wherein the terminal is configured to implement the communication method according to any one of claims 1 to 24.

28. A storage medium storing instructions, characterized in that: When the instruction is executed on a communication device, the communication device is caused to execute the communication method according to any one of claims 1 to 24.

Images