Communication method, first MN, first sn, system and storage medium

Abstract

The present disclosure relates to a communication method, a first MN, a first SN, a system, and a storage medium. The method comprises: a first MN sending first information to a first SN, wherein the first information is used for indicating key-related information of the first SN. Thus, key matching between cells in a mobility process is ensured, the throughput of a terminal is ensured, and communication service quality is improved.

Description

Communication method, first MN, first SN, system and storage medium TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of communication, and particularly relates to a communication method, a first MN, a first SN, a system and a storage medium. BACKGROUND

[0002] In a communication system adopting a DC (Dual Connectivity) architecture, two cell groups are included, a MCG (Master Cell Group) corresponding to a MN (Master Node) at the network side, and a SCG (Secondary Cell Group) corresponding to a SN (Secondary Node) at the network side. The MCG includes one PCell (Primary Cell) and one or more SCells (Secondary Cells). The SCG includes one PSCell (Primary Secondary Cell) and one or more SCells. The PCell and the PSCell can be collectively referred to as sPCell (Special Cell).

[0003] SUMMARY

[0004] To overcome the technical problem of key mismatch in the mobility process in the related art, the present disclosure provides a communication method, a first MN, a first SN, a system and a storage medium.

[0005] According to a first aspect of an embodiment of the present disclosure, a communication method is provided, performed by a first MN, the first MN being a MN to be accessed by a terminal, and the method comprising:

[0006] sending, to a first SN corresponding to the terminal, first information, the first information being used for indicating key related information of the first SN.

[0007] According to a second aspect of an embodiment of the present disclosure, a communication method is provided, performed by a first SN, the first SN being a serving SN and / or a candidate SN of a terminal, and the method comprising:

[0008] receiving first information sent by a first MN, the first information being used for indicating key related information corresponding to the first SN, the first MN being a MN to be accessed by the terminal.

[0009] According to a third aspect of an embodiment of the present disclosure, a first MN is provided, comprising:

[0010] The transceiver is configured to send, to a first SN corresponding to the terminal, first information used to indicate key-related information of the first SN, the first SN being a serving SN and / or a candidate SN of the terminal.

[0011] According to a fourth aspect of the embodiments of the present disclosure, a first SN is provided, comprising:

[0012] The transceiver is configured to receive first information sent by a first MN, the first information being used to indicate key-related information of the first SN, the first MN being an MN to be accessed by the terminal.

[0013] According to a fifth aspect of the embodiments of the present disclosure, a first MN is provided, comprising:

[0014] one or more processors;

[0015] The first MN is configured to perform the communication method according to any one of the first aspect of the present disclosure.

[0016] According to a sixth aspect of the embodiments of the present disclosure, a first SN is provided, comprising:

[0017] one or more processors;

[0018] The first SN is configured to perform the communication method according to any one of the second aspect of the present disclosure.

[0019] According to a seventh aspect of the embodiments of the present disclosure, a communication system is provided, comprising a first MN and a first SN;

[0020] The first MN is configured to send, to a first SN corresponding to the terminal, first information used to indicate key-related information of the first SN, the first SN being a serving SN and / or a candidate SN of the terminal; and the first SN is configured to receive first information sent by a first MN, the first information being used to indicate key-related information of the first SN, the first MN being an MN to be accessed by the terminal.

[0021] According to an eighth aspect of the embodiments of the present disclosure, a storage medium is provided, the storage medium storing instructions, when the instructions are run on a communication device, causing the communication device to perform the communication method according to any one of the first aspect of the present disclosure, or causing the communication device to perform the communication method according to any one of the second aspect of the present disclosure.

[0022] According to a ninth aspect of the embodiments of the present disclosure, a computer program product is provided, including a computer program and / or instructions, which, when executed by a communication device, implement the communication method according to any one of the first aspect of the present disclosure, or which, when executed by a communication device, implement the communication method according to any one of the second aspect of the present disclosure.

[0023] With the above technical solutions, at least the following beneficial technical effects can be achieved:

[0024] The first MN sends first information to the first SN, the first information being used to indicate key related information of the first SN. Thus, the key matching between cells in the mobility process is ensured, the throughput of the terminal is ensured, and the quality of the communication service is improved. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present disclosure, the following describes the drawings required for the embodiments, and the following drawings are only some embodiments of the present disclosure, and do not specifically limit the protection scope of the present disclosure.

[0026] FIG. 1A is a schematic diagram of an architecture of a communication system according to an embodiment of the present disclosure.

[0027] FIG. 1B is a schematic diagram of a DC architecture according to an embodiment of the present disclosure.

[0028] FIG. 1C is a schematic diagram of an NR-DC architecture according to an embodiment of the present disclosure.

[0029] FIG. 1D is a schematic diagram of a flow of inter-gNB mobility handover according to an embodiment of the present disclosure.

[0030] FIG. 1E is a schematic diagram of a flow of an LTM execution process according to an embodiment of the present disclosure.

[0031] FIG. 1F is a schematic diagram of a Key update process of an MN in a handover process according to an embodiment of the present disclosure.

[0032] FIG. 1G is a schematic diagram of a conditional handover flow with a secondary node according to an embodiment of the present disclosure.

[0033] FIG. 2A is an interaction diagram of a communication method according to an embodiment of the present disclosure.

[0034] FIG. 2B is an interaction diagram of a communication method according to an embodiment of the present disclosure.

[0035] FIG. 3 is a schematic diagram of a flow of a communication method according to an embodiment of the present disclosure.

[0036] FIG. 4 is a schematic diagram of a flow of a communication method according to an embodiment of the present disclosure.

[0037] FIG. 5 is an interaction diagram of a communication method according to an embodiment of the present disclosure.

[0038] FIG. 6 is a structural diagram of a first MN according to an embodiment of the present disclosure.

[0039] FIG. 7 is a structural diagram of a first SN according to an embodiment of the present disclosure.

[0040] FIG. 8 is a structural diagram of a communication device 8100 according to an embodiment of the present disclosure.

[0041] FIG. 9 is a structural diagram of a chip 8200 according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0042] Embodiments of the present disclosure provide a communication method, a first MN, a first SN, a system and a storage medium.

[0043] In a first aspect, embodiments of the present disclosure provide a communication method, performed by a first master node MN, the first MN being a MN to which a terminal is to access, the method comprising:

[0044] sending first information to a first secondary node SN corresponding to the terminal, the first information being used to indicate key related information of the first SN, the first SN being a serving SN and / or a candidate SN of the terminal.

[0045] In some embodiments in combination with the first aspect, the sending first information to a first secondary node SN corresponding to the terminal comprises:

[0046] determining that the terminal accesses the first MN, and sending the first information to the first SN.

[0047] In some embodiments in combination with the first aspect, the method further comprises:

[0048] obtaining key configuration information of the terminal;

[0049] determining a first key of the first MN and a key SK counter parameter of the first SN according to the key configuration information;

[0050] determining the first information according to the first key and the SK counter parameter.

[0051] In some embodiments in combination with the first aspect, the first SN is a SN corresponding to a secondary cell SCG configuration in a candidate configuration of the first MN.

[0052] In some embodiments combined with the first aspect, in some embodiments, the sending, to a first secondary node SN corresponding to the terminal, the first information comprises:

[0053] receiving second information sent by the terminal, and sending the first information to the first SN, the second information being used to indicate that the terminal accesses the first MN.

[0054] In some embodiments combined with the first aspect, in some embodiments, the second information comprises at least one of:

[0055] random access information, the random access information comprising Msg1 or Msg3;

[0056] third information, the third information being first uplink transmission information between the terminal and the first MN;

[0057] RRC reconfiguration completion information;

[0058] fourth information, the fourth information being used to indicate that the terminal successfully accesses the first MN.

[0059] In some embodiments combined with the first aspect, in some embodiments, the sending, to a first secondary node SN corresponding to the terminal, the first information comprises:

[0060] receiving fifth information sent by a second MN, and sending the first information to the first SN, the fifth information being used to indicate that the terminal has a mobility process, the second MN being a source MN of the terminal.

[0061] In some embodiments combined with the first aspect, in some embodiments, the fifth information is notification information of L1 / L2 triggered mobility LTM cell switching, and the fifth information comprises at least one of:

[0062] a terminal identifier of the terminal;

[0063] an identifier corresponding to a first MN, the first MN being an MN to which the terminal is to access;

[0064] an identifier corresponding to the second MN;

[0065] a source SN identifier;

[0066] a first SN identifier;

[0067] a candidate configuration identifier;

[0068] mobility type information.

[0069] In some embodiments combined with the first aspect, in some embodiments, the first information comprises sixth information, the sixth information being used to indicate that the SN key of the terminal is unchanged, and the sending, to the first SN corresponding to the terminal, of the first information comprises:

[0070] determining that the first MN is the same as a second MN, the second MN being a source MN of the terminal, and sending, to the first SN, the sixth information.

[0071] In some embodiments combined with the first aspect, in some embodiments, the first information is carried by Xn interface information, the Xn interface information comprising at least one of the following:

[0072] SN addition request information;

[0073] SN modification request information;

[0074] SN reconfiguration complete information.

[0075] In some embodiments combined with the first aspect, in some embodiments, the method further comprises:

[0076] sending, to the terminal, the first information.

[0077] In some embodiments combined with the first aspect, in some embodiments, the first information comprises seventh information, the seventh information comprising MN key information of a MCG corresponding to the access network device and / or SN key information of the first SN.

[0078] In some embodiments combined with the first aspect, in some embodiments, the SN key information comprises an SN key and / or an SK counter parameter.

[0079] In some embodiments combined with the first aspect, in some embodiments, the seventh information is carried by trigger signaling, the trigger signaling being used to trigger the terminal to perform a mobility procedure.

[0080] In some embodiments combined with the first aspect, in some embodiments, the method further comprises:

[0081] receiving the first information sent by the terminal, the first information being generated by the terminal according to an SK counter parameter and key information of a first MN.

[0082] In some embodiments combined with the first aspect, in some embodiments, the first information comprises an SN key list, the SN key list comprising available SN keys of the first MN.

[0083] In some embodiments combined with the first aspect, in some embodiments, the SN key list comprises sequence information, the sequence information being used to identify the available SN keys.

[0084] In some embodiments of the first aspect, in some embodiments, the sequence information comprises at least one of:

[0085] identification information of the SN key;

[0086] an NCC value corresponding to the MN key of the SN key;

[0087] key identification information corresponding to the MN key of the SN key;

[0088] SK counter information corresponding to the SN key.

[0089] In some embodiments of the first aspect, in some embodiments, the method further comprises:

[0090] obtaining an MN key list of the first MN;

[0091] determining SK counter parameters corresponding to the MN key list;

[0092] generating the SN key list according to the SK counter parameters.

[0093] In a second aspect, the embodiments of the present disclosure provide a communication method, which is characterized in that being performed by a first SN, the first SN being a serving SN and / or a candidate SN of a terminal, and the method comprising:

[0094] receiving first information sent by a first MN, the first information being used to indicate key-related information of the first SN, and the first MN being an MN to be accessed by the terminal.

[0095] In some embodiments of the second aspect, in some embodiments, the first information comprises an SN key list, and the SN key list comprises available SN keys of the first MN.

[0096] In some embodiments of the second aspect, in some embodiments, the SN key list comprises sequence information, and the sequence information is used to identify the available SN keys.

[0097] In some embodiments of the second aspect, in some embodiments, the sequence information comprises at least one of:

[0098] identification information of the SN key;

[0099] an NCC value corresponding to the MN key of the SN key;

[0100] key identification information corresponding to the MN key of the SN key;

[0101] SK counter parameters corresponding to the SN key.

[0102] In some embodiments of the second aspect, in some embodiments, the SN key list is determined by the first MN based on a MN key list and an SK counter parameter.

[0103] In some embodiments of the second aspect, in some embodiments, the method further comprises:

[0104] determining an SN key of the first SN from the SN key list, the SN key being a first unused key in the SN key list.

[0105] In some embodiments of the second aspect, in some embodiments, the method further comprises:

[0106] deleting the SN key in the SN key list.

[0107] In some embodiments of the second aspect, in some embodiments, the method further comprises:

[0108] if the second information sent by the first MN is received, determining an SN key of the first SN according to the first information, the second information being used to indicate that a mobility procedure occurs.

[0109] In some embodiments of the second aspect, in some embodiments, the method further comprises:

[0110] if it is determined that a mobility procedure of the terminal is triggered based on a triggering condition, determining an SN key of the first SN according to the first information.

[0111] In some embodiments of the second aspect, in some embodiments, the determining the SN key of the first SN according to the first information comprises:

[0112] determining a first key of the first MN according to the first information, the first MN being a MN to which the terminal is going to access;

[0113] determining the SN key according to the first key.

[0114] In some embodiments of the second aspect, in some embodiments, the first information comprises a mobility configuration, the mobility configuration comprising SN key configuration information corresponding to a candidate configuration.

[0115] In some embodiments of the second aspect, in some embodiments, the SN key configuration information comprises an SK counter parameter, and the method further comprises:

[0116] generating the SN key according to a MN key of a target MCG corresponding to the candidate configuration and the SK counter parameter.

[0117] In some embodiments of the second aspect, in some embodiments, the mobility configuration comprises an SK counter parameter corresponding to the candidate configuration.

[0118] In some embodiments of the second aspect, in some embodiments, the method further comprises:

[0119] determining an MN key of a first MN according to the SN key configuration information, the first MN being a MN to which the terminal is to access;

[0120] determining an SK counter parameter corresponding to the candidate configuration;

[0121] generating the SN key according to the SK counter parameter and the MN key.

[0122] In some embodiments of the second aspect, in some embodiments, the SK counter parameter is a first unused SK counter parameter corresponding to the candidate configuration.

[0123] In a third aspect, an embodiment of the present disclosure provides a first MN, comprising:

[0124] a transceiver configured to send first information to a first SN corresponding to a terminal, the first information being used to indicate key-related information of the first SN, the first SN being a serving SN and / or a candidate SN of the terminal.

[0125] In a fourth aspect, an embodiment of the present disclosure provides a first SN, comprising:

[0126] a transceiver configured to receive first information sent by a first MN, the first information being used to indicate key-related information of the first SN, the first MN being a MN to which the terminal is to access.

[0127] In a fifth aspect, an embodiment of the present disclosure provides a first MN, comprising:

[0128] one or more processors;

[0129] The first MN is configured to perform the communication method of any one of the first aspect of the present disclosure.

[0130] In a sixth aspect, an embodiment of the present disclosure provides a first SN, comprising:

[0131] one or more processors;

[0132] The first SN is configured to perform the communication method of any one of the second aspect of the present disclosure.

[0133] In a seventh aspect, an embodiment of the present disclosure provides a communication system, comprising a first MN and a first SN;

[0134] The first MN is configured to send first information to a first SN corresponding to a terminal, the first information being used to indicate key-related information of the first SN, the first SN being a serving SN and / or a candidate SN of the terminal; and the first SN is configured to receive the first information sent by the first MN, the first information being used to indicate the key-related information of the first SN, the first MN being an MN to be accessed by the terminal.

[0135] In an eighth aspect, the embodiments of the present disclosure provide a storage medium storing instructions, when the instructions are executed on a communication device, causing the communication device to perform the communication method according to any one of the first aspect of the present disclosure, or causing the communication device to perform the communication method according to any one of the second aspect of the present disclosure.

[0136] In a ninth aspect, the embodiments of the present disclosure provide a computer program product, including a computer program and / or instructions, when the computer program and / or instructions are executed by a communication device, realizing the communication method according to any one of the first aspect of the present disclosure, or realizing the communication method according to any one of the second aspect of the present disclosure.

[0137] In a tenth aspect, the embodiments of the present disclosure provide a computer program, when the computer program is executed on a computer, causing the computer to perform the method described in the optional implementation manner of the first aspect and / or the second aspect.

[0138] In an eleventh aspect, the embodiments of the present disclosure provide a chip or a chip system. The chip or the chip system includes processing circuitry configured to perform the method described in the first aspect and / or the optional implementation manner of the second aspect.

[0139] It can be understood that the first MN, the first SN, the communication device, the communication system, the storage medium, the program product, the computer program, the chip or the chip system are all used to execute the method proposed in the embodiments of the present disclosure. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method, which will not be described here.

[0140] The embodiments of the present disclosure provide a communication method, a first MN, a second SN, a system and a storage medium. In some embodiments, the terms of beam indication method, information processing method and communication method can be replaced with each other, the terms of beam indication device, information processing device and communication device can be replaced with each other, and the terms of communication system, information processing system and beam indication system can be replaced with each other.

[0141] The embodiments of the present disclosure are not exhaustive, but only illustrate some embodiments, and are not specific limitations on the protection scope of the present disclosure. In the case of no contradiction, each step in an embodiment can be implemented as an independent embodiment, and the steps can be combined arbitrarily, for example, the scheme after removing part of the steps in an embodiment can also be implemented as an independent embodiment, and the order of the steps in an embodiment can be exchanged arbitrarily, in addition, the optional implementation manners in an embodiment can be combined arbitrarily; in addition, the embodiments can be combined arbitrarily, for example, part or all steps of different embodiments can be combined arbitrarily, an embodiment can be combined with optional implementation manners of other embodiments arbitrarily.

[0142] In each embodiment of the present disclosure, the terms and / or descriptions between the embodiments are consistent if there is no special description and logical conflict, and can be referred to each other, and the technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationship.

[0143] The terms used in the embodiments of the present disclosure are only for the purpose of describing the specific embodiments, and not as a limitation on the present disclosure.

[0144] In the embodiments of the present disclosure, unless otherwise specified, the elements expressed in singular form, such as "one", "a", "the", "above", "said", "preceding", "this" and the like, can represent "one and only one", and can also represent "one or more", "at least one" and the like. For example, in the case of using articles such as "a", "an", "the" and the like in English, the noun after the article can be understood as singular expression, and can also be understood as plural expression.

[0145] In the embodiments of the present disclosure, "plurality" means two or more.

[0146] In some embodiments, the terms "at least one of", "one or more", "a plurality of", "multiple" and the like can be replaced with each other.

[0147] In some embodiments, "at least one of A, B", "A and / or B", "in one case A, in another case B", "responsive to case A, responsive to case B" and the like, can be interpreted to include both cases, A and B, in some embodiments, A (A is performed regardless of B), in some embodiments, B (B is performed regardless of A), in some embodiments, selected from the group consisting of A and B (the selection between A and B is an option), in some embodiments, A and B (both A and B are performed).

[0148] In some embodiments, "A or B" and the like, can be interpreted to include both cases, A and B, in some embodiments, A (A is performed regardless of B), in some embodiments, B (B is performed regardless of A), in some embodiments, selected from the group consisting of A and B (the selection between A and B is an option).

[0149] In some embodiments, the prefix words "first", "second" and the like in the disclosure do not limit the position, order, priority, number or content of the described objects, and the description of the described objects should be referred to the context of the claims or embodiments, and should not be construed as redundant limitations. For example, the described objects are "fields", and the ordinal words before "fields" in "first field" and "second field" do not limit the position or order between "fields", and "first" and "second" do not limit whether the "fields" modified by them are in the same message or not, nor limit the order of "first field" and "second field". For another example, the described objects are "levels", and the ordinal words before "levels" in "first level" and "second level" do not limit the priority between "levels". For another example, the number of the described objects is not limited by the ordinal words, and can be one or more. For example, "first device", where the number of "devices" can be one or more. In addition, the objects modified by different prefix words can be the same or different, for example, the described objects are "devices", and "first device" and "second device" can be the same device or different devices, and their types can be the same or different; for another example, the described objects are "information", and "first information" and "second information" can be the same information or different information, and their contents can be the same or different.

[0150] In some embodiments, "including A", "containing A", "for indicating A", "carrying A" can be interpreted as directly carrying A, or indirectly indicating A.

[0151] In some embodiments, the terms "in response to", "in response to determining", "in the case of", "when", "when", "if", "if" and the like can be replaced with each other.

[0152] In some embodiments, the terms "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 lower than", "above", and the like can be replaced with each other, and the terms "less than", "less than or equal to", "not greater than", "fewer than", "fewer than or equal to", "not more than", "lower than", "lower than or equal to", "not higher than", "below", and the like can be replaced with each other.

[0153] In some embodiments, the apparatuses and devices can be interpreted as physical or virtual, and their names are not limited to the names described in the embodiments, and in some cases can also be understood as "equipment", "device", "circuit", "network element", "node", "function", "unit", "section", "system", "network", "chip", "chip system", "entity", "subject", and the like.

[0154] In some embodiments, "network" can be interpreted as an apparatus included in the network, such as an access network device, a core network device, and the like.

[0155] In some embodiments, an “access network device (AN device)” can also be referred to as a “radio access network device (RAN device),” a “base station (BS),” a “radio base station,” a “fixed station,” and in some embodiments can also be understood as a “node,” an “access point,” a “transmission point (TP),” a “reception point (RP),” a “transmission / reception point (TRP),” a “panel,” an “antenna panel,” an “antenna array,” a “cell,” a “macro cell,” a “small cell,” a “femto cell,” a “pico cell,” a “sector,” a “cell group,” a “serving cell,” a “carrier,” a “component carrier,” a “bandwidth part (BWP),” and the like.

[0156] In some embodiments, a "terminal" or "terminal device" can be referred to as a "user equipment" (UE), a "user terminal," a "mobile station" (MS), a "mobile terminal" (MT), a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communication device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, and / or the like.

[0157] In some embodiments, data, information and / or the like can be obtained in compliance with laws and regulations of a country in which the data, information and / or the like is obtained.

[0158] In some embodiments, data, information and / or the like can be obtained after obtaining consent of a user.

[0159] In addition, each element, each row, or each column in a table of embodiments of the present disclosure can be implemented as an independent embodiment, and a combination of any element, any row, or any column can also be implemented as an independent embodiment.

[0160] FIG. 1A is an architecture diagram of a communication system, according to an embodiment of the present disclosure. As shown in FIG. 1A, the communication system 100 includes a first MN 101 and a first SN 102.

[0161] In some embodiments, the first MN 101 is, for example, a node or a device that accesses a terminal to a wireless network, and the access network device can include at least one of an evolved NodeB (eNB) in a 5G communication system, a next generation eNB (ng-eNB), a next generation NodeB (gNB), a node B (NB), a home node B (HNB), a home evolved node B (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 another communication system, an access node in a Wi-Fi system, but is not limited thereto.

[0162] In some embodiments, the first SN 102 is, for example, a node or a device that accesses a terminal to a wireless network, and the access network device can include at least one of an evolved NodeB (eNB) in a 5G communication system, a next generation eNB (ng-eNB), a next generation NodeB (gNB), a node B (NB), a home node B (HNB), a home evolved node B (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 another communication system, an access node in a Wi-Fi system, but is not limited thereto. For example, the first SN is a serving SN and / or a candidate SN for the terminal.

[0163] In some embodiments, the technical solutions of the present disclosure can be applied to an Open RAN architecture, at this time, the interfaces between or within the access network devices involved in the embodiments of the present disclosure can become internal interfaces of the Open RAN, and the processes and information interactions between these internal interfaces can be implemented through software or programs.

[0164] In some embodiments, the access network device can be composed of a central unit (CU) and a distributed unit (DU), where the CU can also be referred to as a control unit. The CU-DU structure can split the protocol layers of the access network device, and some of the protocol layers are controlled by the CU, and the rest or all of the protocol layers are distributed in the DU and controlled by the CU. However, the present disclosure is not limited thereto.

[0165] It can be understood that the communication system described in the embodiments of the present disclosure is for more clearly illustrating the technical solutions of the embodiments of the present disclosure, and does not constitute a limitation on the technical solutions proposed by the embodiments of the present disclosure. Those skilled in the art can know that, as the system architecture evolves and new business scenarios appear, the technical solutions proposed by the embodiments of the present disclosure are also applicable to similar technical problems.

[0166] The following embodiments of the present disclosure can be applied to the communication system 100 shown in FIG. 1 or part of the subject, but are not limited thereto. The subjects shown in FIG. 1 are exemplary, and the communication system can include all or part of the subjects in FIG. 1, or other subjects other than FIG. 1. The number and form of each subject is arbitrary, each subject can be physical or virtual, the connection relationship between each subject is exemplary, each subject can not be connected or can be connected, the connection can be in any way, can be direct connection or indirect connection, can be wired connection or wireless connection.

[0167] 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 (Bluetooth (registered trademark)), Public Land Mobile Network (PLMN) network, Device-to-Device (D2D) system, Machine to Machine (M2M) system, Internet of Things (IoT) system, Vehicle-to-Everything (V2X), system using other communication methods, next-generation system expanded based thereon, and the like. Further, a plurality of systems can be applied in combination (for example, combination of LTE or LTE-A and 5G, and the like).

[0168] FIG. 1B is a schematic diagram illustrating a DC architecture according to an embodiment of the present disclosure. As shown in FIG. 1B, a cell for initiating initial access is included in the MCG, which is a PCell. Among them, the PCell is the most important cell in the cell corresponding to the MCG. The PCell under the MCG and the SCell under the MCG are jointly included 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 PSCells, and the secondary cells are SCells. In an example, during communication transmission, most control signaling is only sent on the PCell and the PSCell, and therefore, the sPCell is defined in the protocol, which includes the PCell and the PSCell.

[0169] FIG. 1C is a schematic diagram illustrating an NR-DC architecture according to an embodiment of the present disclosure. As shown in FIG. 1C, in the NG-RAN (Next Generation Radio Access Network / 5G Radio Access Network), NR (New Radio)-NR DC (NR-DC dual connectivity) is supported. Based on the NR-DC architecture, a UE (User Equipment) can be connected to a primary gNB acting as an MN and another secondary gNB acting as an SN. Among them, the primary gNB is connected to the 5GC (5G Core) through the NG interface, the primary gNB and the secondary gNB are connected through the Xn interface, and the secondary gNB can also be connected to the 5GC through the NG-U interface. In addition, the NR-DC architecture can also be used for UE to access a single gNB, which can simultaneously act as an MN and an SN, and simultaneously configure an MCG and an SCG.

[0170] FIG. 1D is a flow diagram illustrating a different inter-gNB mobility handover according to an embodiment of the present disclosure. As shown in FIG. 1D, the mobility handover procedure includes: 1, the source gNB initiates the mobility handover, and sends a handover request to the target gNB through the Xn interface; 2, the target gNB performs access control and provides a new RRC configuration as part of the handover request acknowledgement information, and sends the handover request acknowledgement information to the source gNB; 3, the source gNB provides the RRC configuration to the UE by forwarding the RRC (Radio Resource Control) reconfiguration message received in the handover request acknowledgement information. The RRC reconfiguration message includes at least a cell ID and all information required for accessing the target cell, so that the UE can access the target cell without reading the system information. For example, in the random access scenarios based on contention-based random access and non-contention-based random access, all information required for the UE to access the target cell is included in the RRC reconfiguration message, and the access information of the target cell can include beam-specific information; 4, the UE moves the current connection to the target gNB based on the RRC configuration, and feeds back the RRC reconfiguration completion information to the target gNB. For example, based on the above handover procedure, after completing the RRC handover in the UE, the UE can send user data to the target gNB in the case of obtaining authorization.

[0171] In some embodiments, in the NR-based communication architecture, an indication information can be carried in the handover signaling when performing mobility handover, which is used to indicate the target TA (Timing Advance). The TA can be 0, or the TA is the same as that of the source cell.

[0172] In some embodiments, the network side can provide one or more candidate configurations for the UE, and one candidate configuration can include one or more cells. The network side can subsequently control the UE to change among the multiple candidate configurations through L1 signaling (e.g., DCI (Downlink Control Information) or L2 signaling (MAC CE), for example, the UE can be switched from cell-1 to cell-2 based on the L1 signaling. The control signaling can be referred to as cell change control signaling. For example, the cell switching procedure can be referred to as a network-triggered LTM (L1 / L2-triggered Mobility) procedure.

[0173] In some embodiments, the LTM is a procedure of PCell / PSCell cell change triggered by MAC CE based on L1 measurement results of the network, which can be accompanied by a change in MCG and / or SCG in the UE. The gNB receives the L1 measurement report from the UE, and according to the measurement report, issues a cell change signaling through MAC CE to change the serving cell of the UE. In the cell change signaling, an LTM candidate cell configuration is indicated, which is provided to the UE by the gNB through RRC signaling in advance. The UE accesses the target cell indicated by the received cell change signaling, and the LTM-based cell change can be used to reduce the latency in the mobility change process in the UE. The LTM candidate cell configuration is added, modified, and released by the network side through RRC signaling.

[0174] In some embodiments, the LTM procedure in the communication system supports subsequent LTM, which is a subsequent LTM cell change procedure between candidate cells without the need for network-side reconfiguration of RRC. That is, after the UE performs a mobility operation, the UE does not delete the LTM configuration information, and the LTM configuration information can continue to be used without RRC reconfiguration and update, and the subsequent LTM procedure can be triggered based on the LTM configuration information.

[0175] In some embodiments, the LTM configuration information can support gNB-DU intra- movement, gNB-CU intra-movement, and gNB-DU inter-movement communication scenarios. The LTM supports intra-frequency and inter-frequency movement communication scenarios, including inter-frequency cell movement to a non-current serving cell. For example, the following cases are supported: PCell change in non-CA and non-DC scenarios; PCell change in CA scenarios; MCG-PCell change and SCG-PSCell change in dual connectivity scenarios, without the involvement of MN in the change case. For example, SN intra-PSCell change does not support simultaneous change of PCell and PSCell LTM configuration information.

[0176] In some embodiments, the LTM procedure can be supported in the communication system in intra-DU, inter-DU, and intra-CU, but can be extended to support inter-CU LTM procedure in subsequent communication systems. For example, in the inter-CU-LTM procedure for SCG-PSCell change, the MN is involved. The MN can coordinate the configuration information between different CU candidate PSCells.

[0177] In some embodiments, the LTM configures the LTM configuration information through LTM-Config, wherein the LTM configuration information can include at least one of the following: LTM reference configuration information; one or more candidate cell configurations (addition, modification and deletion of candidate cell configurations through a candidate cell to be released list, a candidate cell addition list); LTM-CSI (Channel State Information) resource configuration information.

[0178] Among them, the candidate cell configuration can be configured through LTM-Candidate signaling, which includes at least one of the following: candidate configuration identification; candidate cell identification; candidate configuration (represented by RRC reconfiguration information).

[0179] The LTM candidate configuration is the configuration part of the RRC reconfiguration information associated with the candidate cell, for example, for LTM or subsequent CPAC. The subsequent configuration can be a complete candidate configuration, or a delta configuration relative to the reference configuration.

[0180] The LTM reference configuration is the configuration information provided by the network to the UE, which is the same as a set of configured non-complete candidate configurations within the same cell group.

[0181] Figure 1E is a flow diagram of an LTM execution process according to an embodiment of the present disclosure. As shown in Figure 1E, the subsequent LTM is completed by repeating the early synchronization, LTM cell switching execution and LTM cell switching completion steps, and after each LTM cell switching completion, other LTM candidate configurations are not released. The general procedure of the air interface is applicable to the SCG-LTM process.

[0182] The steps of the LTM execution procedure include: 1. UE sends measurement reporting information to gNB, and gNB determines to configure LTM according to the measurement reporting information and starts LTM preparation; 2. gNB sends RRC reconfiguration information to UE, and the RRC reconfiguration information includes LTM candidate configuration information; 3. UE stores the LTM candidate configuration information and sends RRC reconfiguration completion information to gNB; 4a. UE performs DL synchronization with the candidate cell before receiving the cell switching signaling; 4b. When UE-based TA measurement is configured, UE obtains the TA value of the candidate cell by measurement. Before receiving the cell switching command specified in clause 9.2.6, the UE performs early TA acquisition on the candidate cell according to the network side requirements. This is done through the CFRA (Contention Free Random Access) procedure triggered by the PDCCH (Physical Downlink Control Channel) command of the source cell, and then the UE sends a preamble to the specified candidate cell. In order to minimize the data interruption of the source cell due to sending CFRA to the candidate cell, the UE does not receive the random access response of the network when obtaining the TA value, but indicates the TA value of the candidate cell in the cell switching command. The UE does not maintain the TA timer of the candidate cell, but relies on the network implementation to ensure the validity of the TA; 5. UE performs L1 measurement on the configured candidate cell and sends L1 measurement result report to gNB, wherein if the RRC reconfiguration is applicable, the UE performs L1 measurement; 6. gNB decides to perform cell switching from the current serving cell to the target cell, and sends MAC CE signaling triggering cell switching containing the candidate configuration index of the target cell, and the UE switches to the target cell based on the MAC CE signaling and applies the configuration information indicated by the candidate configuration index; 7. If the UE does not have the valid TA of the target cell specified by the protocol, the UE performs the random access procedure on the target cell; 8. UE completes the LTM cell switching process by sending the RRC reconfiguration completion message to the target cell. If the UE performs the RA (Random Access) procedure in step 7, the UE considers that the LTM cell switching process is completed when the random access procedure is successfully completed. For the LTM procedure without RACH (Random Access CHannel), the UE considers that the LTM cell switching process is completed when the UE determines that the network has successfully received the first UL (Up-Link) data.

[0183] For example, using the LTM candidate configuration information provided in step 2 above, the LTM switching process of steps 4-8 can be performed multiple times to complete subsequent LTM switching. The LTM execution process described above can be applied to both intra-gNB-DU LTM and inter-gNB-DU LTM procedures.

[0184] In some embodiments, a UE in a communication system can perform a mobility switching procedure based on pre-configured condition information on the network side and a pre-configured cell corresponding to the pre-configured condition information. When the UE meets the pre-configured condition (e.g., a specific measurement event), the UE switches the current serving cell to the pre-configured candidate cell. The condition-triggered mobility procedure includes CHO (Conditional Handover), CPA (Conditional PSCell Addition), CPC (Conditional PSCell Change), etc. The UE can also perform a configuration change of a specific cell after meeting the pre-configured condition according to the network side indication, for example, changing the PCell configuration of the UE from candidate cell configuration-1 to candidate cell configuration-2. The condition-triggered mobility procedure also includes Conditional-LTM (condition-triggered LTM procedure), which can be used for MCG switching and SCG switching.

[0185] In some embodiments, the network side specifies support for inter-CU layer 1 / layer 2 triggered mobility LTM procedure. For example, when DC is not configured, the scenario where the CU acts as the MN is prioritized; when DC is configured, the LTM procedure of inter-CU can be configured in the MN or SN, but cannot be configured in both, in which case, as a secondary priority, the scenario where the CU acts as the SN and the MN is unchanged is supported; as a secondary priority, the scenario where the CU acts as the MN and the SN is unchanged or the SN has been released is supported. According to the protocol information, support for subsequent LTM mobility procedures is specified to avoid RRC configuration between cell switches, and coordination with SA3 is required in terms of security key handling. Support for conditional LTM procedures is specified, and the UE evaluation conditions for triggering the LTM procedure are specified to support conditional LTM, including subsequent LTM parameters, and intra-CU LTM procedures are prioritized.

[0186] Figure 1F is a schematic diagram illustrating a Key update procedure for MN in a handover procedure according to an embodiment of the present disclosure. As shown in Figure 1F, in Xn handover procedure, if the source gNB / ng-eNB has unused (NH (the Next Hop parameter), NCC (the Next Hop Chaining Counter parameter)) pair, vertical key derivation should be performed, the source gNB / ng-eNB shall compute KNG-RAN from the target PCI (Physical Cell Identifier), its frequency ARFCN-DL / EARFCN-DL. If it is horizontal key derivation, it is from the currently active KgNB, if it is vertical key derivation, it is from NH. Next, the source gNB / ng-eNB shall forward the (KNG-RAN*, NCC) pair to the target gNB / ng-eNB. The target gNB / ng-eNB shall use the received KNG-RAN* directly as 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 KgNB. The target gNB / ng-eNB shall include the received NCC in the prepared HO (Hand Over) command message, which will be sent back to the source gNB / ng-eNB in a transparent container and forwarded by the source gNB / ng-eNB to the UE.

[0187] In some embodiments, the UE behavior is the same regardless of whether the handover is within gNB-CU, ng-eNB, Xn or N2, but during handover within gNB-CU, the UE can retain the same key according to the indication of gNB. The UE behavior is also the same in the case of conditional handover specified in TS 38.300

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

[0188] In some embodiments, if the UE receives the NCC value in the HO command message from the target ng-eNB / gNB through the source ng-eNB / gNB is equal to the NCC value associated with the current active KgNB / KeNB, the UE shall compute KNG-RAN* from the current active KgNB / KeNB and the target PCI and its frequency ARFCN-DL / EARFCN-DL using the functions defined in A.11 and A.12.

[0189] In some embodiments, if the NCC value received by the UE is different from the NCC associated with the current active KgNB / KeNB, the UE shall first iterate the locally saved NH parameters by 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 through the HO command message. When the NCC value matches, the UE shall calculate KNG-RAN* according to the synchronized NH parameters and the target PCI and its frequency ARFCN-DL / EARFCN-DL using the functions defined in A.11 and A.12. For example, when the UE communicates with the target gNB, KNG-RAN* shall be used as KgNB, and when the UE communicates with the target ng-eNB, KNG-RAN* shall be used as KeNB.

[0190] In some embodiments, inter-gNB LTM procedures are not involved in Rel-18 LTM, so there is no need to update KgNB during the cell handover procedure supporting Rel-18 LTM, because the serving gNB does not change, and the original KgNB can be used between different candidate cells. Therefore, in the candidate configuration of Rel-18 MCG LTM, gNB Key update signaling is not included to indicate the primary key update. However, in Rel-19 inter-gNB LTM, if the processing scheme of the Key in Rel-18 MCG LTM is continued to be used, it will cause the UE to use the same security key before and after performing inter-gNB LTM, which will cause a security key reuse problem.

[0191] In some embodiments, the security scheme focuses on the inter-gNB LTM procedure for MCG in non-DC. Multiple schemes are included:

[0192] Scheme 1: Provide security information using new information in MAC CE. Whether the UE uses horizontal key derivation or vertical key derivation depends on the configuration information in the MAC CE to indicate; Scheme 1A: The LTM cell handover command MAC CE contains the NCC value used when the inter-CU LTM procedure is performed; Scheme 1B: The UE pre-configures a list of NCC values in the encryption and integrity protection RRC message, and the index of the NCC value in the list is contained in the LTM cell handover command MAC CE;

[0193] Scheme 2: Similar to Rel-18 S-CPAC key update mechanism, UE pre-configures the list of NCC values per CU from source gNB using RRC signaling. Participating gNBs are expected to be aware of the list and how UE applies the list during LTM cell handover; Scheme 2A: UE selects the first unused NCC value for target CU when performing inter-CU LTM procedure; Scheme 2B: As an alternative to selecting the next unused NCC value (e.g. as in Scheme 2A), if LTM cell handover is between the same two CUs, then horizontal key derivation is used in this scheme;

[0194] Scheme 3: After performing inter-CU LTM cell handover, participating gNBs will update to new K-gNB* for next inter-CU LTM cell handover. UE and CN are aware of how UE will use the next NCC value. For example, UE determines by itself to use the following NCC value when performing inter-CU LTM later. CN (via RRC signaling indication from source gNB) pre-configures UE with a list of NCC values, and UE selects the first unused NCC value as the next NCC value;

[0195] Scheme 4: After performing inter-CU LTM cell handover each time, UE will obtain the NCC value via RRC signaling for UE to use for key derivation when performing inter-CU LTM cell handover next time.

[0196] In some embodiments, in the schemes 2 and 3 described in the above embodiments, the network side and the UE select a suitable NCC based on a predefined criterion, and find a corresponding NH to generate a key of a target cell. It is used when performing inter-CU LTM cell switching. For example, the network side and the UE can select a corresponding NCC based on a preconfigured NCC value list according to a predefined criterion, determine a corresponding NH to generate a related key; or the network side and the UE increase the NCC or keep the NCC unchanged according to a predefined criterion. However, considering the application scenario of supporting subsequent LTM in inter-CU LTM, frequent switching between each candidate cell is required, and inter-CU LTM and intra-CU LTM can be configured to the UE at the same time, the UE can support CHO, normal switching, and switching configuration of LTM configured at the same time. Therefore, in some specific scenarios, the NCC selected by the UE and the network side may have synchronization errors, so that the keys of the UE and the network side do not match, causing the access process of the UE to fail. Therefore, a method for avoiding key mismatch is proposed in the embodiment, which can align the keys of the network side and the UE in the inter-CU subsequent LTM cell switching process, thereby effectively avoiding the access process failure of the UE when accessing the LTM candidate cell due to key mismatch.

[0197] FIG. 1G is a conditional handover process with a secondary node according to an embodiment of the present disclosure. As shown in FIG. 1G, there are cases where the SN changes and cases where the SN does not change in the process of changing the MN. In the process of conditional handover with a secondary node, if the SN does not change, the target SN is the same as the source SN. The conditional handover procedure with a secondary node is used to configure and perform CHO with SN or CHO with candidate SCG. The process includes cases of preserving, changing or adding SN. If the SN is preserved, the UE context on the SN is preserved. If the SN is changed, the UE context on the source SN is moved to the target SN.

[0198] FIG. 2A is an interaction diagram of a communication method according to an embodiment of the present disclosure. As shown in FIG. 2A, the present disclosure relates to a communication method, and the method includes:

[0199] In step S2101, the access network device sends mobility configuration information to the terminal.

[0200] In an example, in the present embodiment, the access network device is the access network device corresponding to the serving cell of the terminal, for example, the access network device can be the source gNB corresponding to the terminal, and the access network device configures the mobility configuration information for the terminal, which can assist the terminal to perform the next mobility.

[0201] The access network device pre-configures the terminal with mobility configuration information corresponding to the candidate cell, so that the terminal determines a target cell corresponding to next mobility from the candidate cell according to the mobility configuration information. The mobility configuration information can include mobility parameters, measurement report configuration, bearer configuration, RRC configuration, etc., and is used to indicate the configuration corresponding to the mobility of the terminal in the wireless access network and instruct the terminal to perform the mobility process.

[0202] In some embodiments, the mobility configuration information includes at least one of the following: master cell configuration information, master cell group configuration information, primary secondary cell configuration information, secondary cell group configuration information.

[0203] In some embodiments, the terminal receives the mobility configuration information.

[0204] In some embodiments, the mobility configuration information is used to configure one or more candidate configurations.

[0205] In some embodiments, the terminal can determine a target cell from a plurality of candidate cells or a plurality of candidate cell groups according to the signaling information sent by the access network device and the mobility configuration information.

[0206] In some embodiments, the terminal can determine configuration information corresponding to a cell (target cell) to be accessed from a plurality of candidate configurations according to the signaling information sent by the access network device and the mobility configuration information.

[0207] In some embodiments, the signaling information is used to instruct the terminal to perform cell switching in a plurality of candidate cells or a plurality of candidate cell groups, and determine a target cell for a next mobility process from the plurality of candidate cells or the plurality of candidate cell groups according to the mobility configuration information.

[0208] In some embodiments, the mobility configuration information is used to configure one or more candidate configurations and mobility trigger conditions corresponding to the candidate configurations.

[0209] In some embodiments, the mobility configuration information can also be used to instruct the terminal to change the current service configuration of the terminal to a candidate configuration when a network-configured or protocol-agreed trigger condition is met, for example, a mobility process triggered by a condition in the terminal, and the terminal determines that the measurement result corresponding to the first candidate cell meets the mobility switching condition according to the measurement event indicated by the mobility configuration information. The terminal triggers the mobility process. In an example, the candidate configuration can also be referred to as a candidate cell configuration, a candidate cell group configuration, etc.

[0210] In some embodiments, the cell switching condition includes at least one of the following:

[0211] Measurement event A3;

[0212] Measurement event A4;

[0213] Measurement Event A5;

[0214] Triggering event corresponding to cell level measurement result based on physical layer L1 measurement;

[0215] Triggering event of beam level measurement result based on network layer L3 measurement.

[0216] In an example, the terminal in the embodiment changes the current service configuration of the terminal to the candidate cell configuration when the cell switching condition configured by the network or agreed by the protocol is met. The cell switching condition includes at least one of the following: Measurement Event A3, Measurement Event A4, Measurement Event A5, triggering event corresponding to cell level measurement result based on L1 measurement, triggering event of beam level measurement result based on network layer L3 measurement.

[0217] Among them, Measurement Event A3: is usually triggered when the signal quality of the serving cell is lower than a certain threshold, indicating that the terminal needs to switch to a cell with stronger signal. Measurement Event A4: is triggered when the signal quality of the serving cell is lower than a certain threshold and the signal quality of the adjacent cell is higher than that of the serving cell, which usually means that the terminal should switch to the adjacent cell with better signal. Measurement Event A5: is triggered when the signal quality of the serving cell is lower than a certain threshold, and the terminal detects that the signal quality of one or more adjacent cells is higher than that of the serving cell, but the signal quality of these adjacent cells does not exceed a certain threshold. This may mean that the terminal needs to choose between several cells with similar signal quality. The triggering event corresponding to the L1 measurement result is: the decision event of cell selection and switching using the measurement data of the first layer (physical layer). The triggering event corresponding to the L3 measurement result is: the decision event of cell selection and switching using the measurement data of the third layer (network layer).

[0218] In an example, the mobility in the terminal can include conditional trigger-based mobility and / or network signaling trigger-based mobility. For example, any one or more of LTM, CHO, CPAC, Handover, PSCell change, PSCell addition, conditional LTM, etc.

[0219] Among them, the mobility configuration information can be used to support subsequent mobility, that is, the mobility configuration information can be used to perform subsequent continuous execution of corresponding mobility, or the mobility configuration can support continuous mobility in the terminal.

[0220] In an example, the access network device sends mobility configuration information to the terminal in a process of initial configuration of the terminal, the mobility configuration information being the initial configuration of LTM. The initial configuration of LTM is cell configuration information used by the terminal in a cell handover process. The initial configuration of LTM can be used for any one or more of the following: handover decision support, neighbor relation management, handover parameter configuration, load balancing, security and privacy protection, and the like. In the initial configuration stage of LTM, the access network device sends the initial configuration of LTM to the terminal, and the terminal can perform a subsequent mobility process based on the initial configuration of LTM.

[0221] In some embodiments, the mobility configuration information includes NCC information, the NCC information including at least one of:

[0222] one or more NCC values;

[0223] one or more lists of NCC values, each list of NCC values including a plurality of NCC values, the list of NCC values corresponding to a plurality of candidate cells under the same access network device;

[0224] initial NCC information.

[0225] In an example, the key configuration information includes NCC information used to determine key information between the terminal and a target cell in a mobility process. The access network device can pre-configure one or more NCC values for the terminal, and the terminal can select a suitable NCC from the one or more NCC values based on a predefined criterion, and determine a new key based on the suitable NCC. The new key can be used by the terminal to encrypt and decrypt, and integrity protect, data exchanged between the terminal and the target cell after the terminal accesses the target cell. The NCC information includes a list of NCC values, the list of NCC values corresponding to a set of candidate cells under the same access network device, the set of candidate cells including a plurality of candidate cells.

[0226] In some embodiments, the network side can pre-configure a plurality of NCC values for the terminal, and in an example, the plurality of NCC values can be indicated to the terminal in the form of a list of NCC values. The network side can configure one or more lists of NCC values for the terminal, each list of NCC values corresponding to a set of cells, candidate cells in the same set corresponding to the same network node, i.e., candidate cells in the same set being cells under the same candidate gNB. In a subsequent mobility process, the terminal can select a suitable NCC from the list of NCC values based on a predefined criterion, and determine a new key based on the selected NCC for encryption and decryption of data of the target cell and integrity protection.

[0227] In some embodiments, the access network device configures the terminal with initial NCC information, which can be the NCC corresponding to the current serving cell, or the NCC corresponding to other cells. The UE can determine the new key based on the updated NCC during the subsequent mobility procedure, which is used for encryption and decryption of data in the target cell and integrity protection. Alternatively, the terminal can obtain the NCC from the network side based on the configuration of the network side during the subsequent mobility procedure, and determine the new key based on the NCC obtained from the network side, which is used for encryption and decryption of data in the target cell and integrity protection. Alternatively, the terminal can determine the NCC to be used from the list of NCC values preconfigured by the network side based on the predefined criteria during the subsequent mobility procedure, and determine the new key based on the NCC, which is used for encryption and decryption of data in the target cell and integrity protection. AMF Generate NH corresponding to different NCC values, and the key K of the corresponding cell (or node) gNB In subsequent mobility procedures, the terminal can update the initial NCC based on predefined criteria, determine a new key based on the updated NCC, which is used for encryption and decryption of data in the target cell and integrity protection. Alternatively, in subsequent mobility procedures, the terminal can obtain NCC based on network side configuration, determine a new key based on the NCC obtained from the network side, which is used for encryption and decryption of data in the target cell and integrity protection. Alternatively, in subsequent mobility procedures, the terminal can determine the NCC to be used from the list of NCC values preconfigured by the network side based on the predefined criteria, and determine the new key based on the NCC, which is used for encryption and decryption of data in the target cell and integrity protection.

[0228] In some embodiments, the access network device sends key configuration information to the candidate cell.

[0229] In some embodiments, the key configuration information includes NCC information, which includes at least one of:

[0230] Key, such as K gNB ;

[0231] NH;

[0232] NCC value;

[0233] NCC value list, the NCC value list includes a plurality of NCC values, and the NCC value list corresponds to a plurality of candidate cells under the same access network device;

[0234] Initial NCC information;

[0235] NCC information corresponding to NH information.

[0236] NCC information corresponding to the key, such as K gNB ;

[0237] For example, the access network device sends key configuration information to one or more candidate cells corresponding to the terminal, and the key configuration information is used in the candidate cell to determine the key information of the candidate cell based on the key configuration information when the terminal accesses the candidate cell. So that the key information of the terminal and the target cell matches, and ensures the encrypted interaction between the terminal and the target cell.

[0238] In some embodiments, the candidate cell obtains a list of NCC values corresponding to the terminal, and NH or a key corresponding to each NCC value. When the candidate cell obtains the NH, the candidate cell can generate corresponding key information based on the NH and the PCI, DL frequency. The candidate cell can obtain the above information from the initial source cell or from the AMF network element. When the terminal accesses the candidate cell, the candidate cell can determine the NCC corresponding to the terminal based on the manner in which the terminal determines the NCC in the above embodiments, i.e., the candidate cell and the terminal determine the NCC to be used in the candidate cell when the terminal accesses the candidate cell based on the same manner.

[0239] After the candidate cell obtains the list of NCC values corresponding to the terminal and the NH or key information corresponding to each NCC value, the candidate cell can generate or use a corresponding key based on any one or more of the NH, PCI, and DL frequency information. The candidate cell can obtain the LTM initial configuration from the source cell corresponding to the terminal or from the AMF network element. When the terminal accesses the candidate cell, the candidate cell can determine the NCC information corresponding to the candidate cell by referring to the scheme in which the terminal determines the NCC based on the LTM initial configuration, thereby realizing key matching between the terminal and the candidate cell.

[0240] In step S2102, the terminal determines that mobility is triggered, performs mobility access to the first MN according to the mobility configuration, and sends key configuration information to the first MN.

[0241] In an example, the mobility of the terminal in this embodiment can be triggered in the following manner: when the terminal receives mobility signaling (e.g., LTM cell switching signaling) sent by the network side indicating a specific candidate configuration, the terminal triggers the terminal to perform mobility, or when the terminal determines that the target cell satisfies the mobility trigger condition based on the execution condition corresponding to the mobility configuration, the terminal triggers the terminal to perform mobility. When the mobility of the terminal is triggered, the terminal performs mobility based on the mobility configuration configured by the network side.

[0242] In an example, the terminal receives mobility configuration (e.g., handover command) sent by the network side, triggers the terminal to perform mobility, and accesses the target cell corresponding to the mobility configuration.

[0243] In an example, in response to the terminal receiving the LTM configuration in S2101, the LTM configuration including a plurality of LTM candidate configurations, when the UE receives LTM cell switching signaling sent by the network side, the terminal applies the candidate configuration identifier indicated in the LTM cell switching signaling to the corresponding LTM candidate configuration, and performs LTM access to the target cell corresponding to the LTM candidate configuration, which is a cell corresponding to the first MN.

[0244] The first MN corresponds to a network node of a target cell of the terminal, and the target cell is a candidate cell that meets the mobility switching condition in a plurality of candidate cells corresponding to the mobility configuration, that is, the target cell is a cell to be accessed by the terminal. After the terminal triggers mobility, the terminal switches to the target cell of the first MN according to the mobility configuration. The first MN can be the same as the access network device in the above embodiment, that is, the first MN can be a source gNB that sends the mobility configuration to the terminal, and the mobility performed by the terminal can be intra-CU LTM (Intra-Central Unit Layer 1 / Layer 2 Triggered Mobility). Alternatively, the first MN can also be an access network device other than the source gNB, and the mobility performed by the terminal can be inter-CU LTM (inter-Central Unit Layer 1 / Layer 2 Triggered Mobility), and the target cell is a network node corresponding to the first MN.

[0245] In some embodiments, the terminal and the first MN can determine the first key (MN key or K gNB or K MN ) corresponding to the MU based on the mobility configuration information or a predefined accurate determination.

[0246] In some embodiments, the terminal can apply the mobility configuration information corresponding to the first MN to access the PCell / MCG in the candidate cell configuration corresponding to the first MN. When the terminal performs MCG mobility for key update, if the mobility operation needs to retain, update or add an SCG, the candidate configuration corresponding to the mobility includes configuration information corresponding to the SCG. The SN key information on the terminal side can be updated based on the SCG configuration information.

[0247] In some embodiments, the candidate configuration includes configuration information related to the generation of the SN key by the terminal, and the configuration information related to the generation of the SN key is an SK counter parameter. The terminal generates the SN key based on the MN key corresponding to the target MCG and the SK counter parameter.

[0248] In some embodiments, in a mobility communication scenario triggered by network signaling, the configuration information related to the SN key can be carried in the triggering signaling, for example, the SK counter parameter can be carried in the triggering signaling, and the terminal generates the SN key based on the MN key corresponding to the target MCG and the SK counter parameter.

[0249] The SK counter parameter is determined by the first MN, and the first MN can carry the SK counter configuration when generating a candidate configuration in initial mobility configuration, or send the SK counter parameter to the source MN in initial configuration, or send the SN key corresponding SK counter parameter information to the source MN after receiving the indication information sent by the source MN. That is, based on the above embodiments, the UE and the SN can generate SN keys based on the configuration of the source MN and / or the first MN, so that the SN keys can be used for encryption / decryption and integrity protection of transmission on the SN.

[0250] In step S2103, the first MN determines a first key of the first MN based on the key configuration information of the terminal, and generates first information of the first SN according to the first key.

[0251] For example, the target cell can determine the key related information corresponding to the first MN based on the mobility configuration information configured in the terminal. Alternatively, the target cell can also determine the corresponding key related information based on a predefined criterion during the process of the terminal accessing the target cell. For example, the target cell is the first MN, and the target MN can determine the first key corresponding to the MN based on the mobility configuration information in the terminal, or the first MN can determine the first key corresponding to the MN based on a predefined criterion, where the first key can be at least one of the following: MN-key, K gNB , K MN .

[0252] In some embodiments, the first information is used to indicate the key related information corresponding to the first SN.

[0253] In some embodiments, the first information includes an SN key and / or an SK counter parameter.

[0254] In some embodiments, the first information includes an SN key.

[0255] For example, in this embodiment, the first MN is the target MN of the terminal, and the target MN generates key related information of the first SN according to the MN-key. Wherein, the first SN can be a network node corresponding to the SN.

[0256] For example, the first MN generates the key corresponding to the SN according to the key of the MN and the SK counter parameter (sk-counter) information.

[0257] In some embodiments, the SN corresponding to the first SN is the SN corresponding to the SCG configuration in the candidate configuration of the first MN, which can be the current service SN, and can also be other candidate SNs.

[0258] For example, when the terminal triggers inter-CU LTM, the terminal performs cross-base station mobility, switches to a target MN corresponding to a target gNB by the MN of the source gNB, at this time, the SN corresponding to the target MN can be the SN corresponding to the source gNB, and can also be the SN corresponding to other gNBs. When the terminal performs inter-CU LTM, the target MN needs to synchronize the key with the SN, therefore, the target MN needs to send the key-related information to the corresponding target SN, so as to avoid the key mismatch between the terminal and the SN during the mobility process, resulting in access failure.

[0259] In step S2104, the first MN sends first information to the first SN.

[0260] In some embodiments, the first information is used to indicate the key-related information corresponding to the first SN.

[0261] In some embodiments, the first information includes an SN key and / or an SK counter parameter.

[0262] In some embodiments, the first information includes an SN key.

[0263] For example, after determining the key-related information of the first SN, the first MN sends the key-related information to the first SN, so as to synchronize the keys in the first MN, the first SN, and the terminal.

[0264] In some embodiments, the above step S2105 includes:

[0265] The first MN determines that the terminal accesses a target MN corresponding to the first MN, and sends first information to a first SN corresponding to the first SN.

[0266] For example, the first MN is a network node corresponding to the target MN, and the first SN is a network node corresponding to the first SN. After the terminal accesses the target MN through mobility, the SN corresponding to the target MN is the first SN. In response to the target MN receiving random access information sent by the terminal, it is determined that the terminal is performing mobility. The target MN sends corresponding key-related information to the first SN corresponding to the first SN.

[0267] For example, the present embodiment is applicable to inter-CU LTM and a handover process in which the SN does not change. The terminal switches from a source MN corresponding to a source gNB to a target MN corresponding to a target gNB. At this time, the MN accessed by the terminal changes, but the SN accessed by the terminal does not change. That is, the terminal is provided with communication services by the target MN and the source SN, but the key information of the target MN corresponding to the MN after the terminal performs mobility changes. The update state of the corresponding SN key needs to be indicated by the target MN again. Therefore, after the terminal accesses the target MN, the target MN needs to indicate the key-related information to the SN, so as to ensure the key matching during the terminal access process.

[0268] In some embodiments, the first SN triggers the target MN to send the key-related information of the SN to the corresponding SN in response to the target MN receiving a random access preamble sent by the terminal.

[0269] In some embodiments, the step S2105 comprises:

[0270] The first MN sends the first information to the first SN in response to receiving the second information sent by the terminal.

[0271] For example, the second information is used to indicate a mobility procedure of the terminal accessing the target MN, that is, the second information can be any communication interaction information reported by the terminal to the target MN in the process of the terminal accessing the target MN.

[0272] In some embodiments, the second information comprises at least one of:

[0273] Random access information, the random access information comprising Msg1 or Msg3;

[0274] Third information, the third information being first uplink transmission information between the terminal and the target MN;

[0275] RRC reconfiguration completion information;

[0276] Fourth information, the fourth information being used to indicate that the terminal successfully accesses the target MN.

[0277] For example, the second information is used to trigger the target MN in the first MN to send the first information to the SN of the first SN, wherein the second information can comprise random access information Msg1 or Msg3. For example, the first MN sends the key-related information of the SN of the target MN to the SN of the first SN in response to the target MN receiving a random access preamble Msg1 sent by the terminal. The first MN sends the key-related information of the SN of the target MN to the SN of the first SN in response to the target MN receiving uplink transmission (for example, the first MN receiving Msg3) sent by the terminal based on an UL-grant in a RAR (Random Access Response, random access response). The second information can comprise third information, the third information being first uplink transmission information between the terminal and the target MN. For example, the first MN sends the key-related information of the SN of the target MN to the SN of the first SN in response to the target MN first receiving uplink transmission sent by the terminal. The second information can comprise RRC reconfiguration completion information. For example, the first MN sends the key-related information of the SN of the target MN to the SN of the first SN in response to the target MN receiving RRC reconfiguration completion information sent by the terminal.

[0278] In some embodiments, in response to the terminal successfully accessing the target MN, the target MN sends first information corresponding to the SN to the SN corresponding to the first SN.

[0279] In some embodiments, the step S2105 comprises:

[0280] The first MN sends first information to the first SN corresponding to the first SN in response to receiving the fifth information sent by the terminal corresponding to the source MN.

[0281] In some embodiments, the source MN corresponding to the terminal sends the fifth information to the target MN, thereby triggering the target MN to send the key-related information of the SN corresponding to the first SN to the SN.

[0282] In some embodiments, the fifth information is notification information of LTM cell switching, and the fifth information comprises at least one of:

[0283] A terminal identifier of the terminal;

[0284] A source MN identifier;

[0285] A target MN identifier;

[0286] A source SN identifier;

[0287] A service SN identifier;

[0288] A candidate configuration identifier;

[0289] Mobility type information.

[0290] In some embodiments, the source MN sends indication information to the target MN, informing the target MN that the terminal has mobility and accesses the target MN, and the target MN sends corresponding key-related information to the SN after receiving the indication information. The indication information can be LTM cell switching notification information, and the indication information can comprise at least one of the following: a terminal identifier, a source MN identifier, a target MN identifier, a source SN identifier, a target SN identifier (a first SN identifier), a candidate configuration identifier, and mobility type information.

[0291] In some embodiments, when the target MN sends the key-related information to the SN, the target MN can carry a corresponding SK (Security Key, security key) counter parameter in the key-related information. For example, the target MN can determine the corresponding SK counter parameter according to the mobility configuration information of the terminal, generate the key-related information of the first SN according to the SK counter parameter and the first key of the target MN, and to ensure the accuracy of the key-related information, the target MN can carry the corresponding SK counter parameter when sending the key-related information of the SN to the first SN, so that the SN can determine the key of the SN according to the SK counter parameter and the key-related information.

[0292] In some embodiments, the first information comprises sixth information, the sixth information being used to indicate that the SN key of the terminal is unchanged, and the step S2105 comprises:

[0293] The first MN sends the sixth information to the first SN corresponding to the first SN in response to the target MN corresponding to the terminal being the source MN.

[0294] In some embodiments, the target MN can be the source MN, and in this case, the mobility performed by the terminal is intra (in-station)-MN. In this communication scenario, the target MN is the same as the source MN, and the terminal performs SN switching under the same MN based on the mobility. In this case, the terminal can update the key corresponding to the MN, and can also not update the key of the MN. If the key corresponding to the MN is updated, the key corresponding to the SN can be updated based on the updating manner in the above embodiments. If the key corresponding to the MN is not updated, the target MN does not need to send the key corresponding to the SN to the SN. For example, if the target MN is the source MN, the target MN can send indication information to the corresponding first SN during the process of performing mobility by the terminal, so as to instruct the first SN to update the SN key or instruct the SN key in the first SN to be unchanged.

[0295] In some embodiments, the first information is carried by Xn interface information, and the Xn interface information comprises at least one of the following:

[0296] SN addition request information;

[0297] SN modification request information;

[0298] SN reconfiguration complete information.

[0299] Among them, the SN key information can be added in the SN reconfiguration complete information, and the information is sent by the M-NG-RAN node to the S-NG-RAN node to indicate whether the terminal applies the requested configuration corresponding to the S-NG-RAN node. The sending direction of the SN reconfiguration complete information is from the M-NG-RAN node to the S-NG-RAN node.

[0300] In some embodiments, the S-NG-RAN node security key IE is used to apply security in the S-NG-RAN node.

[0301] In an example, the target MN can send the SN corresponding key related information to the SN via Xn information, wherein the Xn information comprises at least one of the following: SN addition request information for indicating adding the SN, SN modification request information for indicating modifying the SN, and SN reconfiguration complete information for indicating the network side SN reconfiguration complete. For example, the first information is carried in the SN reconfiguration complete information, and the SN corresponding SN key information can be added in the SN reconfiguration complete information.

[0302] In step S2105, the first SN determines the SN key corresponding to the first SN according to the first information.

[0303] In some embodiments, the first SN can be a source SN, i.e., the mobility triggered in S2102 is updated for the MN, but the SN is unchanged.

[0304] In some embodiments, the first SN can be a target SN, i.e., the mobility triggered in S2102 is updated for the MN and the SN.

[0305] In some embodiments, the first information includes the SN key. Then the SN key indicated in the first information is the SN key corresponding to the first SN

[0306] In some embodiments, the first information includes an SN key list, and the SN key list includes available SN keys of the target MN corresponding to the first MN.

[0307] In some embodiments, the SN key list includes sequence information, and the sequence information is used to identify the available SN keys.

[0308] In an example, in the mobility preparation process S2101, the candidate target MN needs to pre-configure multiple available SN keys for the SN, and the candidate target MN sends SN key information to the corresponding candidate target SN, wherein the candidate target SN is the SN currently accessed by the UE, and the SN key information carries one or more available SN keys corresponding to the candidate target MN. Optionally, the SN key is associated with a sequence information, and the sequence information is used to identify the available SN keys of the terminal on the candidate target SN corresponding to the MN.

[0309] In an example, the SN key list corresponding to the SN key information is determined by the candidate target MN based on the MN key list obtained by the candidate target MN and one or more SK counter parameters configured by the candidate target MN to the UE.

[0310] In an example, one candidate target SN in this embodiment can be associated with multiple candidate target MNs at the same time, and the SN key available to the terminal on the SN stored by the candidate target SN includes:

[0311] Wherein, the candidate target SN can be associated with multiple target MNs, corresponding to MN A, MN B, MN C, when the terminal cuts into MN A, the SN key available to the UE on the candidate target SN is SN Key A1-SN Key A5; when the terminal cuts into MN B, the SN key available to the UE on the candidate target SN is SN Key B1-SN Key B5; when the terminal cuts into MN C, the SN key available to the UE on the candidate target SN is SN Key C1-SN Key C5, in different target MNs, the SN key available to the terminal on the same candidate target SN can be the same or different, the SN can determine the SN key used by the terminal on the SN based on the available SN key under the corresponding MN, for example, the first available SN key under the target MN can be determined as the SN key used by the terminal on the SN based on the above table.

[0312] For example, the first available SN key under the target MN is determined as the first unused SN key in the SN key list corresponding to the target MN.

[0313] In some embodiments, the sequence information includes at least one of the following:

[0314] The identification information of the SN key;

[0315] The NCC value of the MN key corresponding to the SN key;

[0316] The key identification information of the MN key corresponding to the SN key;

[0317] The SK counter information corresponding to the SN key.

[0318] For example, the sequence information of the SN key can include at least one of the following: the serial number of the SN key in the list; the NCC value of the MN key corresponding to the SN key; the MN key serial number of the MN key corresponding to the SN key; and the SK counter parameter corresponding to the SN key.

[0319] In some embodiments, the SN key list is determined by the target MN based on the MN key list and the SK counter parameter.

[0320] For example, the SN receives the sequence information sent by the target MN to determine the SN key, and the SN finds the SN key corresponding to the sequence information in the SN key list corresponding to the target MN based on the sequence information, and the SN key is used as the SN key corresponding to the terminal for security guarantee of the terminal on the SN. Wherein, the target MN can send the sequence information of the SN key to the SN based on the trigger condition in the above embodiments.

[0321] In some embodiments, the step S2106 comprises:

[0322] determining a target SN key from the SN key list, the target SN key being a first unused key in the SN key list.

[0323] For example, the SN corresponding to the first SN in the embodiment can select the SN key based on a predefined accurate SN key, and in response to the SN determining that the terminal accesses the target SN, the SN selects the first unused SN key in the SN key list corresponding to the target MN as the SN key used by the terminal on the SN.

[0324] In some embodiments, the SN corresponding to the first SN can determine the target MN corresponding to the terminal based on receiving the terminal access indication information sent by the target MN, wherein the access indication information can include S-NODE RECONFIGURATION COMPLETE (S-NODE (Serving Node) reconfiguration complete) information.

[0325] In some embodiments, the method further comprises:

[0326] deleting the target SN key in the SN key list.

[0327] In some embodiments, the names of information, etc. are not limited to the names described in the embodiments, and the terms such as "information", "message", "signal", "signaling", "report", "configuration", "indication", "instruction", "command", "channel", "parameter", "domain", "field", "symbol", "symbol", "codebook", "codeword", "code point", "bit", "data", "program", "chip", etc. can be replaced with each other.

[0328] In some embodiments, the terms such as "codebook", "codeword", and "precoding matrix" can be replaced with each other. For example, the codebook can be a collection of one or more codewords / precoding matrices.

[0329] In some embodiments, the terms “uplink,” “uplink,” “physical uplink,” and the like can be replaced with each other, the terms “downlink,” “downlink,” “physical downlink,” and the like can be replaced with each other, and the terms “side,” “sidelink,” “sidelink communication,” “sidelink communication,” “direct connection,” “direct link,” “direct communication,” “direct link communication,” and the like can be replaced with each other.

[0330] In some embodiments, the terms “downlink control information (DCI),” “downlink (DL) assignment,” “DL DCI,” “uplink (UL) grant,” “UL DCI,” and the like can be replaced with each other.

[0331] In some embodiments, the terms “physical downlink shared channel (PDSCH),” “DL data,” and the like can be replaced with each other, and the terms “physical uplink shared channel (PUSCH),” “UL data,” and the like can be replaced with each other.

[0332] In some embodiments, the terms “radio,” “wireless,” “radio access network (RAN),” “access network (AN),” “RAN-based,” and the like can be replaced with each other.

[0333] In some embodiments, the terms “search space,” “search space set,” “search space configuration,” “search space set configuration,” “control resource set (CORESET),” “CORESET configuration,” and the like can be replaced with each other.

[0334] In some embodiments, the terms “synchronization signal (SS),” “synchronization signal block (SSB),” “reference signal (RS),” “pilot,” “pilot signal,” and the like can be replaced with each other.

[0335] In some embodiments, the terms “moment,” “point in time,” “time,” “time position,” and the like can be replaced with each other, and the terms “duration,” “time period,” “time window,” “window,” “time,” and the like can be replaced with each other.

[0336] In some embodiments, the terms “component carrier (CC),” “cell,” “frequency carrier,” “carrier frequency,” and the like can be replaced with each other.

[0337] In some embodiments, the terms “resource block (RB),” “physical resource block (PRB),” “sub-carrier group (SCG),” “resource element group (REG),” “PRB pair,” “RB pair,” “resource element (RE),” “sub-carrier,” and the like can be replaced with each other.

[0338] In some embodiments, the terms “wireless access scheme,” “waveform,” and the like can be replaced with each other.

[0339] In some embodiments, the terms “precoding”, “precoder”, “weight”, “precoding weight”, “quasi-co-location (QCL)”, “transmission configuration indication (TCI) state”, “spatial relation”, “spatial domain filter”, “transmission power”, “phase rotation”, “antenna port”, “antenna port group”, “layer”, “the number of layers”, “rank”, “resource”, “resource set”, “resource group”, “beam”, “beam width”, “beam angular degree”, “antenna”, “antenna element”, “panel”, and the like can be replaced with each other.

[0340] In some embodiments, the terms “frame”, “radio frame”, “subframe”, “slot”, “sub-slot”, “mini-slot”, “symbol”, “symbol”, “transmission time interval (TTI)”, and the like can be replaced with each other.

[0341] In some embodiments, the terms “acquire”, “obtain”, “get”, “receive”, “transmit”, “bidirectional transmission”, “transmit and / or receive” can be replaced with each other, which can be interpreted as receiving from other subjects, acquiring from protocols, acquiring from higher layers, obtaining by oneself, implementing autonomously, and the like.

[0342] In some embodiments, the terms “transmit”, “emit”, “report”, “issue”, “transmit”, “bidirectional transmission”, “transmit and / or receive”, and the like can be replaced with each other.

[0343] In some embodiments, the terms "certain", "preset", "pre-set", "set", "indicated", "any", "first", and the like can be replaced with each other, and "certain A", "preset A", "pre-set A", "set A", "indicated A", "any A", "first A" can be interpreted as A predetermined in a protocol or the like, or A obtained by setting, configuring, or indicating, or a specific A, any A, or first A, but are not limited thereto.

[0344] In some embodiments, the determination or judgment can be made 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.

[0345] The communication method related to the embodiments of the present disclosure can include at least one of steps S2101-S2106. For example, step S2101 can be implemented as an independent embodiment, step S2102 can be implemented as an independent embodiment, and steps S2102+S2103+S2104 can be implemented as an independent embodiment, but are not limited thereto.

[0346] In some embodiments, the order of any steps in steps S2101-S2106 can be exchanged or executed simultaneously. For example, steps S2102 and S2103 can be exchanged or executed simultaneously.

[0347] In some embodiments, steps S2101-S2106 are optional, and one or more of these steps can be omitted or replaced in different embodiments.

[0348] In some embodiments, other optional implementations described before or after the description corresponding to FIG. 2A can be referred to.

[0349] FIG. 2B is an interaction schematic diagram of a communication method according to an embodiment of the present disclosure. As shown in FIG. 2B, the embodiments of the present disclosure relate to a communication method, and the above method includes:

[0350] In step S2201, the network device sends mobility configuration information to the terminal.

[0351] In an example, the network device is a source gNB of the terminal, and in a preparation phase of a mobility procedure of the terminal, the network device performs an initial configuration process of LTM to send the mobility configuration information to the terminal.

[0352] The optional implementation of step S2201 can refer to the optional implementation of step S2101 in FIG. 2A and other associated parts in the embodiments involved in FIG. 2A, which will not be repeated here.

[0353] In step S2202, the terminal determines the MN key information corresponding to the first MN according to the mobility configuration information.

[0354] In step S2203, the terminal determines the SN key information of the first SN according to the SK counter parameter corresponding to the MN key information and the mobility candidate configuration information.

[0355] For example, the terminal determines the SN key of the first SN based on the mobility configuration information sent by the network side. The mobility configuration information includes the SN key related configuration information corresponding to each candidate configuration. The mobility configuration information includes at least one of the following:

[0356] The mobility configuration information includes the SN key related configuration information corresponding to the terminal generating the mobility configuration, the SK counter parameter, and the terminal generating the SN key based on the MN key corresponding to the target MCG in the mobility configuration and the SK counter parameter (sk-counter).

[0357] The mobility configuration information includes a set of SK counter parameters corresponding to each candidate configuration. Optionally, each SK counter parameter corresponds to a sequence information.

[0358] In some embodiments, based on the mobility triggered by the network signaling, the SN key related configuration information and the SK counter parameter can be carried in the triggering signaling. The terminal can generate the SN key based on the MN key corresponding to the target MCG and the SK counter parameter.

[0359] In some embodiments, in response to the terminal receiving the mobility signaling sent by the network side, the mobility signaling is the mobility signaling indicating a specific candidate configuration, for example, the LTM cell switching signaling; or the execution condition corresponding to the candidate configuration is met, the terminal performs the mobility. The terminal applies the candidate configuration, accesses the target MCG corresponding to the candidate configuration, determines the MN key of the target MN where the target MCG is located, selects the SK counter parameter corresponding to the candidate configuration, and generates the SN key based on the MN key and the SK counter parameter.

[0360] In some embodiments, the terminal selects the SK counter parameter corresponding to the candidate configuration in the mobility configuration parameter configured by the network device. According to the SK counter parameter and the MN key of the target MN, the SN key is generated.

[0361] In some embodiments, the terminal selects a first unused SK counter parameter corresponding to the candidate configuration as the SK counter parameter used when generating the SN key. After generating the SN key, the terminal deletes the used SK counter parameter from the list of SK counter parameters corresponding to the candidate configuration. In this embodiment, the terminal can determine the SN key based on the configuration and predetermined criteria, so that the SN key can be used to encrypt / decrypt and integrity protect data transmission on the SN.

[0362] In some embodiments, the terminal can include the selected SK counter parameter or the sequence information corresponding to the SK counter parameter in the RRC reconfiguration complete information sent to the target MN, and the target MN forwards the information to the target SN or directly sends the information to the SN through a MAC CE. Thus, the SN determines the SN key based on the SK counter parameter or the sequence information corresponding to the SK counter parameter provided by the terminal.

[0363] In some embodiments, the SN determines the SN key used by the terminal on the SN based on the SK counter parameter or the sequence information corresponding to the SK counter parameter from the terminal forwarded by the MN.

[0364] For example, if the SN finds that the SK counter parameter or the sequence information corresponding to the SK counter parameter provided by the terminal and forwarded by the MN is inconsistent with the SK counter parameter or the sequence information corresponding to the SN key currently used by the SN, the SN determines the SN key used by the terminal on the SN based on the SK counter parameter or the sequence information corresponding to the SK counter parameter from the UE forwarded by the MN.

[0365] In step S2204, the terminal sends SN key information to the first MN.

[0366] For example, in this embodiment, the first MN is the target MN to which the terminal is to be accessed. When the terminal performs mobility, the SN key related information corresponding to the SN needs to be updated based on the first information sent by the target MN. To ensure that the terminal can successfully access the SN, the SN key in the terminal needs to be matched with the SN key in the SN. When the SN updates the SN key related information based on the configuration information sent by the node corresponding to the target MN, the terminal needs to update the SN key on the terminal side based on the first information sent by the target MN.

[0367] For example, the terminal applies the mobility configuration information corresponding to the target MN to access the PCell / MCG in the candidate cell configuration corresponding to the target MN. When the terminal performs MCG mobility for key update, if the mobility operation needs to retain, update or add an SCG, the candidate configuration corresponding to the mobility includes configuration information corresponding to the SCG. The SN key information on the terminal side can be updated based on the SCG configuration information.

[0368] In step S2205, the first MN generates first information according to the SN key information and sends the first information to the first SN.

[0369] In some embodiments, the first information includes the SK counter parameter.

[0370] For example, the mobility configuration parameter includes configuration information corresponding to the generation of the SN key by the terminal, and the configuration information includes the SK counter parameter. The terminal generates the SN key related information on the terminal side based on the MN key corresponding to the target MCG and the SK counter parameter.

[0371] In some embodiments, the seventh information is carried by trigger signaling, and the trigger signaling is used to trigger the mobility procedure of the terminal.

[0372] For example, for the mobility triggered based on the network signaling, the SN key related configuration information can be carried in the trigger signaling. The trigger signaling can be handover signaling, LTM cell handover signaling, etc. The terminal can generate the corresponding SN key related information based on the MN key corresponding to the target MCG and the SK counter parameter.

[0373] In some embodiments, the SK counter parameter can be determined by the target MN corresponding to the first MN. The target MN can carry the SK counter parameter configuration when generating the candidate configuration in the initial mobility configuration, or send the SK counter parameter to the source MN in the initial configuration, or trigger the target MN to send the SK counter parameter configuration to the source MN based on the indication information sent by the source MN. The SK counter parameter is the SK counter parameter corresponding to the SN.

[0374] The communication method related to the embodiments of the present disclosure can include at least one of steps S2201-S2205. For example, step S2201 can be implemented as an independent embodiment, step S2202 can be implemented as an independent embodiment, and steps S2202+S2203+S2204 can be implemented as an independent embodiment, but are not limited thereto.

[0375] In some embodiments, the order of any steps in steps S2201-S2205 can be exchanged or executed simultaneously.

[0376] In some embodiments, steps S2201-S2205 are optional, and one or more of the steps can be omitted or replaced in different embodiments.

[0377] In some embodiments, other optional implementations described before or after the description corresponding to FIG. 2B can be referred to.

[0378] FIG. 3 is a flow diagram of a communication method according to an embodiment of the present disclosure. As shown in FIG. 3, the embodiment of the present disclosure relates to a communication method, which is performed by a first MN, and the method comprises:

[0379] In step S3101, first information is sent to a first SN corresponding to the terminal.

[0380] In some embodiments, the first information is used to indicate key-related information of the first SN, and the first SN is a serving SN and / or a candidate SN of the terminal.

[0381] In some embodiments, sending the first information to the first SN corresponding to the terminal comprises:

[0382] In some embodiments, the method further comprises:

[0383] In some embodiments, the method further comprises:

[0384] In some embodiments, the method further comprises:

[0385] In some embodiments, the method further comprises:

[0386] In some embodiments, the method further comprises:

[0387] In some embodiments, the first SN is a SN corresponding to a secondary cell (SCG) configuration in a candidate configuration of the first MN.

[0388] In some embodiments, sending the first information to the first SN corresponding to the terminal comprises:

[0389] In some embodiments, the method further comprises:

[0390] In some embodiments, the second information comprises at least one of:

[0391] In some embodiments, the second information comprises at least one of:

[0392] In some embodiments, the second information comprises at least one of:

[0393] In some embodiments, the second information comprises at least one of:

[0394] In some embodiments, the second information comprises at least one of:

[0395] In some embodiments, sending the first information to the first SN corresponding to the terminal comprises:

[0396] receive fifth information sent by the second MN, and send first information to the first SN, the fifth information being used to indicate that the terminal has a mobility procedure, and the second MN being a source MN of the terminal.

[0397] In some embodiments, the fifth information is notification information of L1 / L2 triggered mobility LTM cell switching, and the fifth information includes at least one of the following:

[0398] a terminal identifier of the terminal;

[0399] an identifier corresponding to the first MN, the first MN being an MN to be accessed by the terminal;

[0400] an identifier corresponding to the second MN;

[0401] a source SN identifier;

[0402] a first SN identifier;

[0403] a candidate configuration identifier;

[0404] mobility type information.

[0405] In some embodiments, the first information includes sixth information, the sixth information being used to indicate that an SN key of the terminal is unchanged, and the first information is sent to a first SN corresponding to the terminal, and the first information includes at least one of the following:

[0406] determine that the first MN is the same as the second MN, and send the sixth information to the first SN, the second MN being a source MN of the terminal.

[0407] In some embodiments, the first information is carried by Xn interface information, and the Xn interface information includes at least one of the following:

[0408] SN addition request information;

[0409] SN modification request information;

[0410] SN reconfiguration complete information.

[0411] In some embodiments, the method further includes:

[0412] sending the first information to the terminal.

[0413] In some embodiments, the first information includes seventh information, and the seventh information includes MN key information of an MCG corresponding to the access network device and / or SN key information of the first SN.

[0414] In some embodiments, the SN key information includes an SN key and / or an SK counter parameter.

[0415] In some embodiments, the seventh information is carried by trigger signaling, and the trigger signaling is used to trigger the terminal to perform a mobility procedure.

[0416] In some embodiments, the method further includes:

[0417] receiving first information sent by the terminal, the first information being generated by the terminal according to the SK counter parameter and the key information of the first MN.

[0418] In some embodiments, the first information includes an SN key list, and the SN key list includes available SN keys of the first MN.

[0419] In some embodiments, the SN key list includes sequence information, and the sequence information is used to identify the available SN keys.

[0420] In some embodiments, the sequence information includes at least one of:

[0421] identification information of the SN key;

[0422] an NCC value of the MN key corresponding to the SN key;

[0423] key identification information of the MN key corresponding to the SN key;

[0424] SK counter information corresponding to the SN key.

[0425] In some embodiments, the method further includes:

[0426] obtaining an MN key list of the first MN;

[0427] determining an SK counter parameter corresponding to the MN key list;

[0428] generating an SN key list according to the SK counter parameter.

[0429] In some embodiments, other optional implementations described before or after the description corresponding to FIG. 3 can be referred to.

[0430] FIG. 4 is a flow diagram of a communication method according to an embodiment of the present disclosure. As shown in FIG. 4, the embodiment of the present disclosure relates to a communication method, which is performed by a first SN, and the above-mentioned method includes:

[0431] Step S4101, receiving first information sent by a first MN.

[0432] In some embodiments, the first information is used to indicate key-related information of the first SN, and the first MN is an MN to be accessed by the terminal.

[0433] Optional implementations of step S4101 can be referred to optional implementations of step S2105 of FIG. 2A and other associated parts in the embodiments related to FIG. 2A, which will not be described here.

[0434] The optional implementation of step S4101 can be found in the optional implementation of step S2204 in Figure 2B, and other related parts in the embodiments involved in Figure 2B, which will not be repeated here.

[0435] In some embodiments, the SN key list includes available SN keys of the first MN.

[0436] In some embodiments, the SN key list includes sequence information used to identify the available SN keys.

[0437] In some embodiments, the sequence information includes at least one of the following:

[0438] Identification information of the SN key;

[0439] The SN key corresponds to the NCC value of the MN key;

[0440] The SN key corresponds to the key identification information of the MN key;

[0441] The SK counter parameters corresponding to the SN key.

[0442] In some embodiments, the SN key list is determined by the first MN based on the MN key list and the SK counter parameter.

[0443] In some embodiments, the method further includes:

[0444] The SN key of the first SN is determined from the SN key list, wherein the SN key is the first unused key in the SN key list.

[0445] In some embodiments, the method further includes:

[0446] Delete the SN key from the SN key list.

[0447] In some embodiments, the method further includes:

[0448] If the second information sent by the first MN is received, the SN key of the first SN is determined based on the first information, and the second information is used to indicate that the terminal has undergone a mobility process.

[0449] In some embodiments, the method further includes:

[0450] If the terminal mobility process is determined to be triggered based on the triggering conditions, then the SN key of the first SN is determined according to the first information.

[0451] In some embodiments, determining the SN key based on the first information includes:

[0452] determining a first key of a first MN according to the first information, the first MN being a MN to which the terminal is going to access;

[0453] determining the SN key according to the first key.

[0454] In some embodiments, the first information comprises a mobility configuration, the mobility configuration comprising SN key configuration information corresponding to the candidate configuration.

[0455] In some embodiments, the SN key configuration information comprises an SK counter parameter, and the method further comprises:

[0456] generating the SN key according to the MN key of the target MCG corresponding to the candidate configuration and the SK counter parameter.

[0457] In some embodiments, the mobility configuration comprises an SK counter parameter corresponding to the candidate configuration.

[0458] In some embodiments, the method further comprises:

[0459] determining a MN key of a first MN according to the SN key configuration information, the first MN being a MN to which the terminal is going to access;

[0460] determining an SK counter parameter corresponding to the candidate configuration;

[0461] generating the SN key according to the SK counter parameter and the MN key.

[0462] In some embodiments, the SK counter parameter is a first unused SK counter parameter corresponding to the candidate configuration.

[0463] In some embodiments, other optional implementations described before or after the description corresponding to FIG. 4 can be referred to.

[0464] FIG. 5 is an interaction schematic diagram of a communication method according to an embodiment of the present disclosure. As shown in FIG. 5, the embodiment of the present disclosure relates to a communication method, and the above method comprises:

[0465] In step S5101, when the UE performs LTM access to the target MN, the target MN sends the updated SN key to the serving SN.

[0466] For example, after receiving the MN reconfiguration complete message carrying the SN reconfiguration complete message sent by the UE, the target MN generates an SN key based on the MN key and the SK counter parameter configured for the UE, and sends the SN key to the SN through the S-NODE reconfiguration complete message of the Xn interface together with the SN reconfiguration complete message sent by the UE.

[0467] In step S5102, the SN selects the first unused key corresponding to the target MN as the SN key corresponding to the UE.

[0468] For example, the candidate target MN sends the SN key list to the source SN. When the UE performs MN update and accesses the target MN, in the preparation process of the MCG LTM, after the SN receives the SN reconfiguration complete message sent by the target MN, the MN accessed by the UE is determined, and the first unused key corresponding to the MN is selected as the SN key corresponding to the UE.

[0469] In some embodiments, the network side provides one or more candidate configurations (for example, candidate configurations provided by the RRC reconfiguration message) to the terminal side, wherein the candidate configuration can include cell (or cell group) configuration. For example, the cell (or cell group) configuration can be the primary cell (or primary cell group) configuration and / or the primary secondary cell (or secondary cell group) configuration.

[0470] In some embodiments, the use of the candidate configuration can include that the network side can subsequently control the terminal to change in multiple candidate cells (or candidate cell groups) through signaling; when the terminal meets the trigger condition configured or agreed by the network, the terminal changes the configuration to the candidate cell (or candidate cell group) configuration, for example, when the terminal meets the measurement event A3 or A4 or A5 event, the serving cell (or serving cell group) configuration is changed to the corresponding candidate cell (or candidate cell group). The trigger condition includes but is not limited to any one or more of the following events: a trigger event corresponding to a cell-level measurement result based on L3 measurement, and / or a trigger event based on beam-level measurement result of L1 measurement.

[0471] In some embodiments, the network side pre-configures multiple NCC values for the UE, which can be represented by an NCC value list; the network side can configure one NCC value list for the UE or the network side can configure multiple value lists for the UE, each NCC value list corresponds to a cell set, and the candidate cells in the same set are cells under the same candidate gNB. In the subsequent mobility process, the UE can select a suitable NCC based on the pre-defined criteria in the NCC value list, and determine a new key based on the selected NCC for the encryption and decryption of the target cell data and the integrity protection.

[0472] In some embodiments, in response to the UE receiving the mobility command (for example, LTM Cell Switch Command) sent by the network side indicating a specific candidate configuration, or the execution condition corresponding to the candidate configuration is met (applicable to "mobility based on conditional triggering", for example, LTM based on conditional triggering), the UE applies the candidate configuration to perform mobility. In some embodiments, the network side provides one or more candidate configurations (for example, candidate configurations provided by the RRC reconfiguration message) to the terminal side, wherein the candidate configuration can include cell (or cell group) configuration. For example, the cell (or cell group) configuration can be the primary cell (or primary cell group) configuration and / or the primary secondary cell (or secondary cell group) configuration.

[0470] In some embodiments, the use of the candidate configuration can include that the network side can subsequently control the terminal to change in multiple candidate cells (or candidate cell groups) through signaling; when the terminal meets the trigger condition configured or agreed by the network, the terminal changes the configuration to the candidate cell (or candidate cell group) configuration, for example, when the terminal meets the measurement event A3 or A4 or A5 event, the serving cell (or serving cell group) configuration is changed to the corresponding candidate cell (or candidate cell group). The trigger condition includes but is not limited to any one or more of the following events: a trigger event corresponding to a cell-level measurement result based on L3 measurement, and / or a trigger event based on beam-level measurement result of L1 measurement.

[0471] In some embodiments, the network side pre-configures multiple NCC values for the UE, which can be represented by an NCC value list; the network side can configure one NCC value list for the UE or the network side can configure multiple value lists for the UE, each NCC value list corresponds to a cell set, and the candidate cells in the same set are cells under the same candidate gNB. In the subsequent mobility process, the UE can select a suitable NCC based on the pre-defined criteria in the NCC value list, and determine a new key based on the selected NCC for the encryption and decryption of the target cell data and the integrity protection.

[0472] In some embodiments, in response to the UE receiving the mobility command (for example, LTM Cell Switch Command) sent by the network side indicating a specific candidate configuration, or the execution condition corresponding to the candidate configuration is met (applicable to "mobility based on conditional triggering", for example, LTM based on conditional triggering), the UE applies the candidate configuration to perform mobility.

[0473] In some embodiments, the UE and the target MN determine the first key corresponding to the MN based on the information configured in the above embodiments or predefined criteria.

[0474] In some embodiments, the target MN generates a SN key based on the key of the MN, and the target MN sends the SN corresponding key (e.g., the SN key or K SN or S-K gNB ) to the SN. Wherein, the SN is the SN corresponding to the SCG configuration in the candidate configuration of the target MN, and the SN can be the current serving SN or other candidate target SN.

[0475] In some embodiments, in response to the target MN receiving any one or more of the following information sent by the UE, the target MN sends the SN corresponding key to the SN:

[0476] In response to the target MN receiving a random access preamble (receiving Msg1) sent by the UE, the target MN sends the SN corresponding key to the SN;

[0477] In response to the target MN receiving an uplink transmission (e.g., receiving Msg3) sent by the UE based on the UL grant in the RAR (Random Access Response), the target MN sends the SN corresponding key to the SN;

[0478] In response to the target MN first receiving an uplink transmission sent by the UE, the target MN sends the SN corresponding key to the SN;

[0479] In response to the target MN receiving an RRC reconfiguration complete message sent by the UE, the target MN sends the SN corresponding key to the SN;

[0480] In response to the UE successfully accessing the target MN, the target MN sends the SN corresponding key to the SN.

[0481] In some embodiments, in response to the target MN receiving any one or more of the following information sent by the source MN, the target MN sends the SN corresponding key to the SN:

[0482] The source MN sends indication information to the target MN, informing the target MN that the UE has mobility and accesses the target MN, and the target MN sends the SN corresponding key to the SN after receiving the indication information. Wherein, the indication information can be an LTM cell handover notification message, and the indication information can include any one or more of the following information: UE identifier, source MN identifier, target MN identifier, corresponding source SN identifier, target SN identifier, candidate configuration identifier, mobility type, etc.

[0483] In some embodiments, the MN determines the SK counter parameter, generates the SN key based on the SK counter parameter and the MN key; the target MN can also carry the corresponding SK counter parameter when sending the SN key corresponding to the SN to the SN.

[0484] In some embodiments, the target MN can be the source MN (performing intra-MN mobility), in which case the UE can or can not update the MN key; if the MN key is updated, the corresponding SN key is updated according to the above scheme, otherwise, the target MN does not need to send the SN key corresponding to the SN to the SN; optionally, the target MN can send indication information to the SN to indicate that the SN key corresponding to the UE remains unchanged.

[0485] In some embodiments, the target MN can send the SN key corresponding to the SN to the SN through an Xn message, which includes but is not limited to any one or more of the following information: addition request message, modification request message, reconfiguration completion message (such as SN reconfiguration completion message). For example, the SN key information can be added in the SN reconfiguration completion message.

[0486] Among them, the SN key information can be added in the SN reconfiguration completion information, which is sent by the M-NG-RAN node to the S-NG-RAN node to indicate whether the terminal applies the requested configuration corresponding to the S-NG-RAN node. The sending direction of the SN reconfiguration completion information is from the M-NG-RAN node to the S-NG-RAN node.

[0487] In some embodiments, the S-NG-RAN node security key IE is used to apply security in the S-NG-RAN node.

[0488] In some embodiments, the UE applies the candidate configuration corresponding to the target MN, accesses the PCell / MCG in the candidate cell configuration corresponding to the target MN, and when performing key update MCG mobility, if the mobility operation needs to be reserved, updated, added SCG, the candidate configuration corresponding to the mobility can include the configuration corresponding to the SCG, and in order to support the SN key update on the UE side, the following two schemes can be included:

[0489] The candidate configuration includes SN key related configuration information generated by the UE, wherein the SN key related configuration information is: the SK counter parameter, and the UE generates the SN key based on the MN key corresponding to the target MCG and the SK counter parameter;

[0490] For network signaling based mobility, the SN key related configuration information SK counter parameter can be carried in the triggering signaling (e.g., handover command, LTM cell handover signaling), and the UE generates the SN key based on the MN key corresponding to the target MCG and the SK counter parameter.

[0491] The SK counter parameter is determined by the target MN, which can carry the SK counter parameter configuration when generating the candidate configuration in the initial mobility configuration, or send the SK counter parameter to the source MN in the initial configuration, or send the SN key corresponding SK counter parameter to the source MN after receiving the indication information sent by the source MN. The UE and the SN can both generate the SN key based on the configuration of the source MN (and / or) the target MN, so as to encrypt / decrypt and integrity protect the transmission on the SN using the SN key.

[0492] In some embodiments, during the mobility preparation process, the candidate target MN needs to pre-configure multiple available SN keys for the SN. In the mobility preparation phase, the candidate target MN sends SN key information to the corresponding candidate target SN (the target SN can be the SN currently accessed by the UE), and the SN key information carries one or more available SN keys corresponding to the candidate target MN. Optionally, each SN key is associated with a sequence information, which uniquely identifies the SN key available for the UE on the candidate target SN.

[0493] The SN key information corresponds to the SN key list obtained by the candidate target MN based on the MN key list and one or more SK counter parameters configured by the candidate target MN to the UE.

[0494] In some embodiments, one candidate target SN can be associated with multiple candidate target MNs at the same time, and the SN stored SN key available for the UE on this SN is as follows: taking three candidate target MNs A, B and C as an example, each MN provides 5 available SN keys for the SN. For MN A, MN B and MN C, the SN keys in the sequence numbers 1-5 can be the same or different:

[0495] In some embodiments, the sequence information of the SN key can be any one or more of the following information:

[0496] The sequence number of the SN key in the list;

[0497] The NCC value corresponding to the MN key corresponding to the SN key;

[0498] The sequence number of the MN key corresponding to the MN key corresponding to the SN key;

[0499] The SN key corresponds to the SK timer parameter.

[0500] In some embodiments, the UE performs mobility, and when accessing the SN, the SN determines the selected SN key by any one or more of the following schemes:

[0501] (1) Method requiring the target MN to provide sequence information: the SN receives the sequence information sent by the target MN to determine the SN key, and the SN looks up the sequence information corresponding to the SN key in the SN key list corresponding to the target MN. The SN key corresponding to the sequence information is used as the SN key corresponding to the UE for security guarantee of the UE transmission on the SN.

[0502] Wherein, when and how the target MN sends the SN key sequence information to the SN can refer to the method of the target MN sending the SN key to the SN in the above embodiments, except that the SN key is replaced by the sequence information corresponding to the SN key.

[0503] (2) Method without requiring the target MN to provide information, SN selects the SN key based on the pre-defined criteria: in response to the SN determining the target MN accessed by the UE; the SN selects the first unused SN key in the SN key list corresponding to the target MN as the SN key corresponding to the UE.

[0504] Wherein, the SN can determine the target MN by the following method: in response to the SN receiving the UE access indication information sent by the target MN, wherein the access indication information is S-NODE Reconfiguration Complete information.

[0505] Wherein, the UE performing mobility includes: in response to the UE receiving the mobility command sent by the network side indicating a specific candidate configuration, or the execution condition corresponding to the candidate configuration is met (applicable to "conditional triggered mobility", such as conditional triggered LTM), the UE performs the mobility (such as LTM), applies the candidate configuration, and the UE and the target MN determine the first key (MN key or K gNB , also known as K MN ) corresponding to the MN based on the information configured in 0.3 or the pre-defined criteria.

[0506] In some embodiments, the UE receives the mobility configuration sent by the network side, and the mobility configuration information contains the SN key related configuration information corresponding to each candidate configuration (or candidate configuration group), including any one or more of the following cases:

[0507] The candidate configuration contains the SN key related configuration information SK counter parameter generated by the UE, and the UE generates the SN key based on the MN key corresponding to the target MCG corresponding to the candidate configuration and the SK counter parameter;

[0508] The mobility configuration information configures a set of SK counter parameters corresponding to each candidate configuration (or candidate configuration group), and optionally, each SK counter parameter corresponds to a sequence information.

[0509] In some embodiments, for network signaling triggered mobility, the UE can generate the SN key based on the MN key corresponding to the target MCG and the SK counter parameters carried in the triggering signaling (e.g., handover command, LTM cell handover signaling).

[0510] In some embodiments, in response to the UE receiving a mobility command sent by the network side indicating a specific candidate configuration, or the execution condition corresponding to the candidate configuration being met, the UE performs the mobility, applies the candidate configuration, accesses the target MCG corresponding to the candidate configuration, determines the MN key of the target MN where the target MCG is located, selects the SK counter parameters corresponding to the candidate configuration, and generates the SN key based on the MN key and the SK counter parameters.

[0511] For example, the UE can select the SK counter parameters corresponding to the candidate configuration configured by the network side. The UE can also select the first unused SK counter parameter corresponding to the candidate configuration, and delete the used SK counter parameter from the list of SK counter parameters corresponding to the candidate configuration. The UE and the SN can both determine the SN key based on the configuration and predefined criteria, so that the SN key can be used for encryption / decryption and integrity protection of transmissions on the SN.

[0512] In some embodiments, the UE can include the selected SK counter parameters, or the sequence information corresponding to the SK counter parameters, in the MN RRC reconfiguration complete message sent to the target MN, which is forwarded to the target SN by the target MN, or directly sent to the SN through a MAC CE, so that the SN determines the SN key based on the first SK counter parameters or sequence information provided by the UE.

[0513] In some embodiments, the SN selects the SN key corresponding to the first SK counter parameters or sequence information from the UE forwarded by the MN. For example, if the SN finds that the first SK counter parameters or sequence information provided by the UE forwarded by the MN is inconsistent with the second SK counter parameters or sequence information corresponding to the SN key selected by the SN, the SN selects the SN key corresponding to the first SK counter parameters or sequence information from the UE forwarded by the MN.

[0514] The embodiments of the present disclosure further provide a device for implementing any of the above methods, for example, a device comprising units or modules for implementing the steps performed by the terminal in any of the above methods. For another example, another device is provided, comprising units or modules for implementing the steps performed by the network device (such as an access network device, a core network function node, a core network device, etc.) in any of the above methods.

[0515] It should be understood that the division of each unit or module in the above device is only a logical function division, and all or part of the units or modules can be integrated into one physical entity or physically separated in actual implementation. In addition, the units or modules in the device can be implemented in the form of processor invoking software: for example, the device comprises a processor connected with a memory, the memory stores instructions, and the processor invokes the instructions stored in the memory to implement any of the above methods or to implement the functions of each unit or module of the device, wherein the processor is a general processor such as a central processing unit (CPU) or a microprocessor, and the memory is a memory in the device or a memory outside the device. Alternatively, the units or modules in the device can be implemented in the form of hardware circuit, and the functions of part or all of the units or modules can be implemented by the design of the hardware circuit, and the hardware circuit can be understood as one or more processors; for example, in one implementation, the hardware circuit is an application-specific integrated circuit (ASIC), and the functions of part or all of the units or modules are implemented by the design of the logical relationship between the elements in the circuit; for another example, in another implementation, the hardware circuit is a programmable logic device (PLD), and 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 a configuration file, so as to implement the functions of part or all of the units or modules. All units or modules of the above device can be implemented in the form of processor invoking software, or all units or modules can be implemented in the form of hardware circuit, or part of the units or modules are implemented in the form of processor invoking software, and the remaining part is implemented in the form of hardware circuit.

[0516] In the embodiments of the present disclosure, the processor is a circuit with signal processing capability. In one implementation, the processor can be a circuit with instruction reading and running capability, such as a central processing unit (CPU), a microprocessor, a graphics processing unit (GPU) (which can be understood as a microprocessor), a digital signal processor (DSP), or the like. In another implementation, the processor can implement certain functions through a logical relationship of a hardware circuit, and the logical relationship of the hardware circuit is fixed or can be reconfigured. 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 the reconfigurable hardware circuit, the processor loads a configuration document to implement the configuration of the hardware circuit. It can be understood that the processor loads instructions to implement the functions of the above part or all units or modules. In addition, the hardware circuit can also be 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), and the like.

[0517] FIG. 6 is a structural schematic diagram of a first MN according to the embodiments of the present disclosure. As shown in FIG. 6, the first MN 6100 can include a transceiver module 6101. In some embodiments, the transceiver module 6101 is configured to send first information to a first SN corresponding to a terminal, the first information being used to indicate key-related information of the first SN, the first SN being a serving SN and / or a candidate SN of the terminal. Optionally, the transceiver module 6101 is configured to perform at least one of the determining and / or obtaining and / or the like communication steps performed by the first MN 101 in any of the above methods, which will not be described herein.

[0518] In some embodiments, the transceiver module can include a receiving module and a sending module, which can be separate or integrated together. Optionally, the sending module can be replaced by the transmitter. The receiving module can be replaced by the receiver.

[0519] FIG. 7 is a structural schematic diagram of a first SN according to an embodiment of the present disclosure. As shown in FIG. 7, the first SN 7100 can include a transceiver module 7101. In some embodiments, the transceiver module 7101 is configured to receive first information sent by a first MN, the first information being used to indicate key-related information of the first SN, the first MN being an MN to be accessed by the terminal. Optionally, the transceiver module 7101 is configured to perform at least one of the determining and / or obtaining and / or the like communication steps performed by the first SN 102 in any of the above methods, which are not described herein again.

[0520] In some embodiments, the transceiver module can include a receiving module and a sending module, which can be separate or integrated together. Optionally, the sending module can be replaced by a transmitter. The receiving module can be replaced by a receiver.

[0521] FIG. 8 is a structural schematic diagram of a communication device 8100 according to an embodiment of the present disclosure. The communication device 8100 can be a network device (for example, an access network device, a core network device, or the like), a terminal (for example, a user equipment or the like), a chip, a chip system, or a processor supporting the network device to implement any of the above methods, or a chip, a chip system, or a processor supporting the terminal to implement any of the above methods. The communication device 8100 can be used to implement the methods described in the above method embodiments, and specific implementation can be referred to the descriptions in the above method embodiments.

[0522] As shown in FIG. 8, the communication device 8100 includes one or more third processors 8101. The third processor 8101 can be a general-purpose processor or a special-purpose processor, for example, a baseband processor or a central processing unit. The baseband processor can be used to process communication protocols and communication data, and the central processing unit can be used to control the communication device (for example, a base station, a baseband chip, a terminal device, a terminal device chip, a DU or a CU, or the like), execute programs, and process data of the programs. Optionally, the communication device 8100 is configured to perform any of the above methods. Optionally, the one or more third processors 8101 are configured to invoke instructions to enable the communication device 8100 to perform any of the above methods.

[0523] In some embodiments, the communication device 8100 further includes one or more third transceivers 8102. When the communication device 8100 includes one or more third transceivers 8102, the third transceiver 8102 performs at least one of the communication steps of sending and / or receiving in the above-described methods, and the third processor 8101 performs at least one of the other steps. In optional embodiments, a transceiver can include a receiver and / or a transmitter, which can be separate or integrated together. Optionally, the terms transceiver, transceiving unit, transceiver, transceiving circuit, interface circuit, interface, and the like can be replaced with each other, the terms transmitter, transmitting unit, transmitter, transmitting circuit, and the like can be replaced with each other, and the terms receiver, receiving unit, receiver, receiving circuit, and the like can be replaced with each other.

[0524] In some embodiments, the communication device 8100 further includes one or more third memories 8103 for storing data. Optionally, all or part of the third memory 8103 can also be outside the communication device 8100. In optional embodiments, the communication device 8100 can include one or more first interface circuits 8104. Optionally, the first interface circuit 8104 is connected to the third memory 8103, and the first interface circuit 8104 can be used to receive data from the third memory 8103 or other devices, and can be used to send data to the third processor 8101 or other devices. For example, the first interface circuit 8104 can read the data stored in the third memory 8103 and send the data to the third processor 8101.

[0525] The communication device 8100 described in the above embodiments can 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 can not be limited by Figure 8. The communication device can be a standalone device or can be part of a larger device. For example, the communication device can be: 1) a standalone integrated circuit (IC), or a chip, or a chip system or subsystem; (2) a set of one or more ICs, which can optionally include storage components for storing data, programs; (3) an ASIC, such as a modem; (4) a module that can be embedded in other devices; (5) a receiver, a terminal device, a smart terminal device, a cellular phone, a wireless device, a handset, a mobile unit, a vehicle-mounted device, a network device, a cloud device, an artificial intelligence device, and the like; (6) others, and the like.

[0526] Figure 9 is a structural schematic diagram of a chip 8200 according to an embodiment of the present disclosure. For the case where the communication device 8100 is a chip or a chip system, reference can be made to the structural schematic diagram of the chip 8200 shown in Figure 9, but not limited thereto.

[0527] The chip 8200 includes one or more fourth processors 8201. The chip 8200 is configured to perform any of the above methods.

[0528] In some embodiments, the chip 8200 further includes one or more second interface circuits 8202. Optionally, the terms interface circuit, interface, transceiver pin, etc. can replace each other. In some embodiments, the chip 8200 further includes one or more fourth memories 8203 configured to store data. Optionally, all or part of the fourth memory 8203 can be outside the chip 8200. Optionally, the second interface circuit 8202 is connected with the fourth memory 8203, the second interface circuit 8202 can be configured to receive data from the fourth memory 8203 or other devices, and the second interface circuit 8202 can be configured to send data to the fourth memory 8203 or other devices. For example, the second interface circuit 8202 can read the data stored in the fourth memory 8203 and send the data to the fourth processor 8201.

[0529] In some embodiments, the second interface circuit 8202 performs at least one of the communication steps such as sending and / or receiving in the above methods. The second interface circuit 8202 performs the communication steps such as sending and / or receiving in the above methods, for example, means that the second interface circuit 8202 performs data interaction between the fourth processor 8201, the chip 8200, the fourth memory 8203 or the transceiver device. In some embodiments, the fourth processor 8201 performs at least one of the other steps.

[0530] The modules and / or devices described in each of the embodiments of the virtual device, the physical device, the chip, etc. can be combined or separated according to the situation. Optionally, part or all of the steps can also be performed by multiple modules and / or devices in cooperation, which is not limited here.

[0531] The disclosure also proposes a storage medium, and the above storage medium stores instructions, when the instructions run on the communication device 8100, the communication device 8100 performs any of the above methods. Optionally, the above storage medium is an electronic storage medium. Optionally, the above storage medium is a computer readable storage medium, but is not limited to this, it can also be a storage medium readable by other devices. Optionally, the above storage medium can be a non-transitory storage medium, but is not limited to this, it can also be a transitory storage medium.

[0532] The disclosure also proposes a program product, and the above program product is executed by the communication device 8100, so that the communication device 8100 performs any of the above methods. Optionally, the above program product is a computer program product.

[0533] The disclosure also proposes a computer program, when it runs on a computer, the computer performs any of the above methods.

Claims

1. A communication method characterized by comprising: The method is performed by a first master node MN, the first MN being a MN to which a terminal is to access, and the method comprises: sending, to a first secondary node SN corresponding to the terminal, first information, the first information being used to indicate key related information of the first SN, the first SN being a serving SN and / or a candidate SN of the terminal.

2. The method of claim 1, wherein, The sending, to the first secondary node SN corresponding to the terminal, of the first information comprises: determining that the terminal accesses the first MN, and sending the first information to the first SN.

3. The method of claim 2, wherein, The method further comprises: obtaining key configuration information of the terminal; determining, according to the key configuration information, a first key of the first MN and a key SK counter parameter of the first SN; determining the first information according to the first key and the SK counter parameter.

4. The method according to claim 2 or 3, characterized in that, The first SN is a SN corresponding to a secondary cell SCG configuration in a candidate configuration corresponding to the first MN.

5. The method of claim 1, wherein, The sending, to the first secondary node SN corresponding to the terminal, of the first information comprises: receiving second information sent by the terminal, and sending the first information to the first SN, the second information being used to indicate that the terminal accesses the first MN.

6. The method of claim 5, wherein, The second information comprises at least one of: random access information, the random access information comprising Msg1 or Msg3; third information, the third information being first uplink transmission information between the terminal and the first MN; RRC reconfiguration completion information; fourth information, the fourth information being used to indicate that the terminal successfully accesses the first MN.

7. The method of claim 1, wherein, The sending, to the first secondary node SN corresponding to the terminal, of the first information comprises: receiving fifth information sent by a second MN, and sending the first information to the first SN, the fifth information being used to indicate that a mobility procedure occurs for the terminal, the second MN being a source MN of the terminal.

8. The method of claim 7, wherein, The fifth information is notification information of L1 / L2 triggered mobility LTM cell switching, and the fifth information comprises at least one of: a terminal identifier of the terminal; an identifier corresponding to the first MN, the first MN being a MN to which the terminal is to access; an identifier corresponding to the second MN; a source SN identifier; a first SN identifier; a candidate configuration identifier; mobility type information.

9. The method of claim 1, wherein, The first information comprises sixth information, the sixth information being used to indicate that a SN key of the terminal is unchanged, and the sending, to the first secondary node SN corresponding to the terminal, of the first information comprises: determining that the first MN is the same as a second MN, and sending the sixth information to the first SN, the second MN being a source MN of the terminal.

10. The method according to any one of claims 1-9, characterized in that, The first information is carried by Xn interface information, and the Xn interface information comprises at least one of: SN addition request information; SN modification request information; SN reconfiguration completion information.

11. The method of claim 1, wherein, The method further comprises: sending the first information to the terminal.

12. The method of claim 13, wherein, The first information comprises seventh information, the seventh information comprising MN key information of a MCG corresponding to the access network device, and / or SN key information of the first SN.

13. The method of claim 12, wherein, The SN key information comprises a SN key and / or a SK counter parameter.

14. The method of claim 12, wherein, The seventh information is carried by trigger signaling, and the trigger signaling is used to trigger the terminal to perform a mobility procedure.

15. The method of claim 1, wherein, The method further includes: receiving the first information sent by the terminal, the first information being generated by the terminal according to SK counter parameters and key information of the first MN.

16. The method of claim 1, wherein, The first information includes an SN key list, and the SN key list includes available SN keys of the first MN.

17. The method of claim 16, wherein, The SN key list includes sequence information used to identify the available SN keys.

18. The method of claim 17, wherein, The sequence information includes at least one of the following: identification information of an SN key; an NCC value of an MN key corresponding to the SN key; key identification information of an MN key corresponding to the SN key; SK counter information corresponding to the SN key.

19. The method of claim 17 or 18, wherein, The method further includes: obtaining an MN key list of the first MN; determining SK counter parameters corresponding to the MN key list; generating the SN key list according to the SK counter parameters.

20. A method of communication, comprising: The method is performed by a first SN, the first SN being a serving SN and / or a candidate SN of a terminal, and the method includes: receiving first information sent by a first MN, the first information being used to indicate key-related information of the first SN, and the first MN being an MN to be accessed by the terminal.

21. The method of claim 20, wherein, The first information includes an SN key list, and the SN key list includes available SN keys of the first MN.

22. The method of claim 21, wherein, The SN key list includes sequence information used to identify the available SN keys.

23. The method of claim 22, wherein, The sequence information includes at least one of the following: identification information of an SN key; an NCC value of an MN key corresponding to the SN key; key identification information of an MN key corresponding to the SN key; SK counter parameters corresponding to the SN key.

24. The method of any one of claims 21-23, wherein, The SN key list is determined by the first MN based on an MN key list and SK counter parameters.

25. The method of any one of claims 21-24, wherein, The method further includes: determining, from the SN key list, an SN key of the first SN, the SN key being a first unused key in the SN key list.

26. The method of claim 25, wherein, The method further includes: deleting the SN key in the SN key list.

27. The method of any one of claims 20-26, wherein, The method further includes: if second information sent by the first MN is received, determining an SN key of the first SN according to the first information, the second information being used to indicate that a mobility procedure of the terminal occurs.

28. The method of any one of claims 20-26, wherein, The method further includes: if it is determined that a mobility procedure of the terminal is triggered based on a trigger condition, determining an SN key of the first SN according to the first information.

29. The method of claim 27 or 28, wherein, The determining of the SN key of the first SN according to the first information includes: determining a first key of the first MN according to the first information, the first MN being an MN to be accessed by the terminal; and determining the SN key according to the first key.

30. The method of any one of claims 27 or 28, wherein, The first information includes a mobility configuration, and the mobility configuration includes SN key configuration information corresponding to a candidate configuration.

31. The method of claim 30, wherein, The SN key configuration information includes SK counter parameters, and the method further includes: generating the SN key according to an MN key of a target MCG corresponding to the candidate configuration and the SK counter parameters.

32. The method of claim 30 or 31, wherein, The mobility configuration includes an SK counter parameter corresponding to the candidate configuration.

33. The method of claim 31, wherein, The method further includes: determining an MN key of a first MN according to the SN key configuration information, the first MN being a MN to which the terminal is to access; determining an SK counter parameter corresponding to the candidate configuration; generating the SN key according to the SK counter parameter and the MN key.

34. The method of claim 33, wherein, The SK counter parameter is a first unused SK counter parameter corresponding to the candidate configuration.

35. A first MN, characterized by Comprise: a transceiver configured to send first information to a first SN corresponding to the terminal, the first information being used to indicate key related information of the first SN, the first SN being a serving SN and / or a candidate SN of the terminal.

36. A first SN, wherein, Comprise: a transceiver configured to receive first information sent by a first MN, the first information being used to indicate key related information of the first SN, the first MN being a MN to which the terminal is to access.

37. A first MN, characterized by Comprise: one or more processors; wherein the first MN is configured to perform the communication method of any one of claims 1-19.

38. A first SN, wherein the first SN is configured to: Comprise: one or more processors; wherein the first SN is configured to perform the communication method of any one of claims 20-34.

39. A communication system, characterized by Comprise a first MN and a first SN; wherein the first MN is configured to send first information to a first SN corresponding to the terminal, the first information being used to indicate key related information of the first SN; and the first SN is configured to receive the first information sent by the access network device, the first information being used to indicate key related information corresponding to the first SN.

40. A storage medium, the storage medium storing instructions, wherein, When the instructions run on the communication device, the communication device performs the communication method of any one of claims 1-19, or the communication device performs the communication method of any one of claims 20-34.

41. A computer program product comprising computer programs and / or instructions, characterized in that, The computer program and / or instructions, when executed by the communication device, implement the communication method of any one of claims 1-19, or the computer program and / or instructions, when executed by the communication device, implement the communication method of any one of claims 20-34.

Images