Method and device used for wireless communication

Abstract

Disclosed are a method and device for wireless communication, comprising: receiving a first signaling, the first signaling comprising at least one NCC and at least one candidate configuration; wherein any one candidate configuration in the at least one candidate configuration aims at one candidate target cell; executing a first candidate configuration in the at least one candidate configuration; along with the execution of the first candidate configuration in the at least one candidate configuration, selecting a first NCC in the at least one NCC, the first NCC corresponding to a first NH parameter; exporting a first key according to the first NH parameter; in response to performing completion of the first candidate configuration, a first message is sent, the first message indicating the first NCC. According to the method provided by the invention, the capacity of NCC and NH parameters can be increased, and the signaling overhead can be reduced.

Description

Technical Field

[0001] The present application relates to methods and devices related to security in a cellular wireless communication system, and particularly to a method for determining a key during a mobility cell handover triggered by layer 1 and layer 2. Background Art

[0002] The application scenarios of future wireless communication systems are becoming increasingly diversified, and different application scenarios pose different performance requirements on the system. In order to meet the different performance requirements of various application scenarios, it was decided at the 72nd plenary session of 3GPP (3rd Generation Partner Project) RAN (Radio Access Network) to conduct research on the new air interface technology (NR, New Radio) (or Fifth Generation, 5G). At the 75th plenary session of 3GPP RAN, the WI (Work Item) of NR was adopted, and the standardization work of NR began.

[0003] In communication, whether it is LTE (Long Term Evolution) or 5G NR, it involves the accurate reception of reliable information, optimized energy efficiency ratio, determination of information effectiveness, flexible resource allocation, scalable system architecture, efficient non-access stratum information processing, low service interruption and disconnection rates, support for low power consumption, which is of great significance for the normal communication between base stations and user equipment, for the reasonable scheduling of resources, and for the balance of system load. It can be said to be the cornerstone of high throughput, meeting the communication needs of various services, improving spectrum utilization, and improving service quality. It is indispensable for both eMBB (enhanced Mobile BroadBand), URLLC (Ultra Reliable Low Latency Communication), and eMTC (enhanced Machine Type Communication). At the same time, in the IIoT (Industrial Internet of Things in the industrial field), in V2X (Vehicular to X), in device-to-device communication, in communication on unlicensed spectrum, in user communication quality monitoring, in network planning and optimization, in TN (Territerial Network), in dual connectivity systems, in wireless resource management and the selection of multi-antenna codebooks, in signaling design, neighbor cell management, service management, and in beamforming, there are extensive requirements. The information sending methods are divided into broadcast and unicast, and both sending methods are essential for the 5G system because they are very helpful for meeting the above requirements.

[0004] With the continuous increase in the scenarios and complexity of the system, higher requirements are put forward for reducing the interruption rate, reducing latency, enhancing reliability, enhancing system stability, for service flexibility, and for power saving. At the same time, compatibility between different system versions also needs to be considered during system design. Summary of the Invention

[0005] The researchers found that in the scenario of determining the NH (next hop) parameter, if the NH parameter is determined only by a single NCC in the network configuration, it is necessary to configure the NCC every time before updating the NH parameter, which lacks flexibility. The researchers further found that LTM (L1 / L2 Triggered Mobility) cell switch has significant technological progress compared with the traditional layer-3-based handover, which can greatly shorten the handover delay and better ensure the continuity of data transmission. At the same time, LTM cell switch supports continuous handover, which can perform continuous handover between different cells, especially between cells belonging to / associated with different control units (CUs), that is, there is no need to reconfigure the handover parameters between two consecutive handovers, which can avoid reconfiguring the handover parameters including the configuration of the target cell during the handover process, facilitating the shortening of the handover delay, reducing the signaling overhead, and providing flexibility. When the key needs to be updated during LTM cell switch, especially during continuous handover, if a new NCC is configured before each handover, it will become a bottleneck for continuous handover.

[0006] In view of the above problems, the present application provides a solution.

[0007] It should be noted that, without conflict, the embodiments and the features in the embodiments in any node of the present application can be applied to any other node. Without conflict, the embodiments and the features in the embodiments of the present application can be combined with each other arbitrarily. At the same time, the method proposed in the present application can also be used to solve other problems in communication, such as NR evolution and problems in 6G systems.

[0008] As an embodiment, the interpretation of the terms in the present application refers to the definitions in the 3GPP specification protocol series TS38.

[0009] As an embodiment, the interpretation of the terms in the present application refers to the definitions in the 3GPP specification protocol series TS37.

[0010] The present application discloses a method applied to a terminal for wireless communication, including: receiving a first signaling, where the first signaling includes at least one NCC (Next Hop Chain Counter) and at least one candidate configuration; wherein, any one of the at least one candidate configurations is configured for a candidate target cell.

[0011] Execute the first candidate configuration among the at least one candidate configuration; along with the execution of the first candidate configuration among the at least one candidate configuration, select a first NCC among the at least one NCC, where the first NCC corresponds to a first NH parameter; derive a first key according to the first NH parameter;

[0012] As a response to the completion of the execution of the first candidate configuration, send a first message, where the first message indicates the first NCC.

[0013] As an embodiment, the problems to be solved by the present application include: if the NCC is determined more flexibly and then the NH parameter is determined, how to keep the synchronization of the NCC and the NH parameter between the terminal and the network.

[0014] As an embodiment, the benefits of the above method include: more flexible, supporting a larger number of NH parameters, more secure, better supporting cell handover, especially LTM cell handover, and cell handover between CUs (control units).

[0015] Specifically, according to one aspect of the present application, the at least one NCC includes multiple NCCs.

[0016] Specifically, according to one aspect of the present application, the execution of the first candidate configuration among the at least one candidate configuration depends on the satisfaction of a first condition, where the first condition is the reception of a second signaling, the cell selected when the T311 timer is running is the candidate target cell configured by the first candidate configuration, and one of the conditional events associated with the first candidate configuration is satisfied.

[0017] Wherein, the second signaling indicates the first candidate configuration.

[0018] Specifically, according to one aspect of the present application, the conditional event associated with the first candidate configuration is an event for conditional handover or an event for conditional LTM.

[0019] Specifically, according to one aspect of the present application, the first message sends the first NCC in plain text.

[0020] Specifically, according to one aspect of the present application, the first message includes a first container, the first container carries the first NCC, and the key used by the first container is maintained by the terminal source cell.

[0021] Specifically, according to one aspect of the present application, the selection of the first NCC among the at least one NCC includes: selecting an unused NCC among the at least one NCC as the first NCC.

[0022] Specifically, according to one aspect of the present application, the first message indicates the number of unused NCCs in the at least one NCC.

[0023] Specifically, according to one aspect of the present application, execute the second candidate configuration among the at least one candidate configuration; along with the execution of the second candidate configuration among the at least one candidate configuration, select a second NCC in the at least one NCC, where the second NCC corresponds to a second NH parameter; derive a second key according to the second NH parameter;

[0024] As a response to the completion of the execution of the second candidate configuration, send a second message, and the second message indicates the second NCC.

[0025] Specifically, according to one aspect of the present application, the terminal is a user equipment.

[0026] Specifically, according to one aspect of the present application, the terminal is a vehicle-mounted terminal.

[0027] Specifically, according to one aspect of the present application, the terminal is a mobile phone.

[0028] The present application discloses a terminal used in wireless communication, including:

[0029] One or more processors and a memory;

[0030] The memory is coupled to the one or more processors, and the memory is used to store computer program code. The computer program code includes computer instructions, and the one or more processors call the computer instructions to cause the terminal to execute the methods described in any one of the methods in the terminal.

[0031] As an embodiment, compared with the traditional solution, the present application has the following advantages:

[0032] More flexible, supporting the terminal to autonomously select NCC and / or autonomously determine the NH parameter when the terminal performs cell handover, especially conditional cell handover.

[0033] Ensures the consistency between the terminal and the network in terms of security.

[0034] More secure, for example, when switching between different base stations, such as when switching between CUs, the security. For example, there is no need to configure the same key for each candidate cell or base station.

[0035] Better support for LTM continuous handover.

[0036] More signaling overhead is saved.

[0037] Reduces the handover delay. Description of the Drawings

[0038] Other features, objects, and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0039] Figure 1 A schematic diagram showing receiving a first signaling, executing a first candidate configuration among at least one candidate configuration, selecting a first NCC among at least one NCC, deriving a first key according to a first NH parameter, and sending a first message according to an embodiment of the present application;

[0040] Figure 2 A schematic diagram showing a network architecture according to an embodiment of the present application;

[0041] Figure 3 A schematic diagram showing an embodiment of a radio protocol architecture of a user plane and a control plane according to an embodiment of the present application;

[0042] Figure 4 A schematic diagram showing a first communication device and a second communication device according to an embodiment of the present application;

[0043] Figure 5 A flowchart showing wireless signal transmission according to an embodiment of the present application;

[0044] Figure 6 A schematic diagram showing key generation according to an embodiment of the present application;

[0045] Figure 7 A schematic diagram showing a first NH parameter for deriving a first key according to an embodiment of the present application;

[0046] Figure 8 A schematic diagram showing cell handover according to an embodiment of the present application;

[0047] Figure 9 An example of a schematic diagram of a processing device for a terminal according to an embodiment of the present application. Detailed Embodiments

[0048] The technical solutions of the present application will be further described in detail below in conjunction with the accompanying drawings. It should be noted that, without conflict, the embodiments and features in the embodiments of the present application can be combined with each other arbitrarily.

[0049] Example 1

[0050] Example 1 exemplifies a flowchart of receiving first signaling according to an embodiment of the present application, executing a first candidate configuration among at least one candidate configuration, selecting a first NCC from at least one NCC, deriving a first key according to a first NH parameter, and sending a first message, as shown in the appendix Figure 1 as follows. In the appendix Figure 1 each box represents a step. It should be particularly emphasized that the order of the boxes in the figure does not represent the temporal sequence of the steps represented.

[0051] In Example 1, the terminal in the present application receives first signaling in step 101, executes a first candidate configuration among at least one candidate configuration in step 102, selects a first NCC from at least one NCC in step 103, derives a first key according to a first NH parameter in step 104; and sends a first message in step 105;

[0052] wherein, the first signaling includes at least one NCC (Next Hop Chain Counter) and at least one candidate configuration; wherein, any candidate configuration among the at least one candidate configuration configures for a candidate target cell; the first NCC corresponds to a first NH parameter; the first message indicates the first NCC.

[0053] As an embodiment, the terminal is a UE (User Equipment).

[0054] As an embodiment, the terminal is a mobile phone terminal.

[0055] As an embodiment, the present application is directed to a terminal in the RRC connected state.

[0056] As an embodiment, in the art, cell handover includes L3 (Layer-3) cell handover and LTM.

[0057] As an embodiment, for the MAC sublayer, the higher layers include the RRC sublayer, the NAS layer, the RLC sublayer, and the PDCP sublayer.

[0058] Typically, the higher layer when operating in the MAC sublayer is the RRC sublayer.

[0059] As an embodiment, for the RRC sublayer, the higher layers include the application layer and the NAS layer.

[0060] Typically, the higher layer when operating in the RRC sublayer includes the NAS.

[0061] As an embodiment, for the PDCP sublayer, the higher layers include the RRC sublayer and the NAS layer.

[0062] As an example, the lower layers when operations are performed at the RRC sublayer include at least one of the physical layer, the MAC sublayer, the RLC sublayer, and the PDCP sublayer.

[0063] As an example, the higher layer signaling includes RRC signaling or signaling of the non-access stratum.

[0064] As an example, in this application, if not specifically indicated to be performed at the MAC sublayer, it is performed at the RRC sublayer or the NAS.

[0065] As an example, the access stratum security of the terminal is activated.

[0066] As an example, the access stratum (AS) includes multiple protocol layers. For detailed content, reference can be made to Embodiment 3.

[0067] As an example, the terminal is in the RRC connected state.

[0068] As an example, any parameter in this application is either configured by the network or can be generated by the terminal according to an internal algorithm, such as randomly.

[0069] As an example, the values of the timers in this application are all finite and do not exceed 2560 milliseconds.

[0070] As an example, the value of the timer is the running time when the timer is not intervened.

[0071] As an example, the value of any parameter in this application, including but not limited to the value of the timer and the value of the counter, is finite unless otherwise stated.

[0072] As a sub-embodiment of this embodiment, the upper limit of the value of any parameter in this application is 1024 times 65536.

[0073] As a sub-embodiment of this embodiment, the upper limit of the value of any parameter in this application is 65536 or 65535.

[0074] As a sub-embodiment of this embodiment, the upper limit of the value of any parameter in this application is 1024.

[0075] As a sub-embodiment of this embodiment, the upper limit of the value of any parameter in this application is 640 or 320.

[0076] As an example, this application is for NR.

[0077] As an example, this application is for an evolved wireless communication network of NR.

[0078] As an example, the serving cell refers to the cell where the UE camps. Performing cell search includes the UE searching for a suitable cell of the selected PLMN (Public Land Mobile Network) or SNPN (Stand-alone Non-Public Network), selecting the suitable cell to provide available services, and monitoring the control channel of the suitable cell. This process is defined as camping on the cell; that is, a camped cell is the serving cell of this UE with respect to this UE. Camping on a cell in the RRC idle state or RRC inactive state has the following advantages: enabling the UE to receive system messages from the PLMN or SNPN; when registered, if the UE wishes to establish an RRC connection or resume a suspended RRC connection, the UE can achieve this by performing initial access on the control channel of the camped cell; the network can page the UE; enabling the UE to receive ETWS (Earthquake and Tsunami Warning System) and CMAS (Commercial Mobile Alert System) notifications.

[0079] As an example, for a UE in the RRC connected state without configured CA / DC (carrier aggregation / dual connectivity), there is only one serving cell including the primary cell. For a UE in the RRC connected state with configured CA / DC (carrier aggregation / dual connectivity), the serving cell is used to indicate the cell set including the special cell (SpCell, Special Cell) and all secondary cells. The primary cell is the MCG (Master Cell Group) cell, operating on the primary frequency, and the UE performs the initial connection establishment process or initiates connection reestablishment on the primary cell. For dual connectivity operation, the special cell refers to the PCell (Primary Cell) of the MCG or the PSCell (Primary SCG Cell) of the SCG (Secondary Cell Group); if it is not dual connectivity operation, the special cell refers to the PCell.

[0080] As an example, the frequency on which the SCell (Secondary Cell) operates is the secondary frequency.

[0081] As an example, the method proposed in this application does not limit whether DC is configured.

[0082] As an example, the terminal is only configured with MCG.

[0083] As an example, the separate content of an information element is called a domain.

[0084] As an example, MR-DC (Multi-Radio Dual Connectivity) refers to the dual connectivity between an E-UTRA and an NR node, or the dual connectivity between two NR nodes.

[0085] As an example, in MR-DC, the radio access node that provides the control plane connection to the core network is the master node, and the master node can be the master eNB, the master ng-eNB, or the master gNB.

[0086] As an example, MCG refers to a set of serving cells associated with the master node in MR-DC, including the SpCell, and may also optionally include one or more SCell.

[0087] As an example, the PCell is the SpCell of the MCG.

[0088] As an example, the PSCell is the SpCell of the SCG.

[0089] As an example, in MR-DC, the radio access node that does not provide the control plane connection to the core network and provides additional resources to the UE is the secondary node. The secondary node can be an en-gNB, a secondary ng-eNB, or a secondary gNB.

[0090] As an example, in MR-DC, a set of serving cells associated with the secondary node is the SCG (secondary cell group), including the SpCell and, optionally, one or more SCell.

[0091] As an example, the SpCell is the PCell or the SpCell is the PSCell.

[0092] As an example, in the RRC inactive state, DC is not used.

[0093] As an example, in the RRC inactive state, CA is typically not used.

[0094] As an example, the RRC information block refers to the information element in the RRC message.

[0095] As an example, the SSB can be referred to as SS / PBCH, or SS block.

[0096] As an example, L1 is Layer 1 or the physical layer.

[0097] As an example, L2 is Layer 2.

[0098] As an example, this application is directed to networks for NR and NR evolution, such as 6G networks.

[0099] As an example, an RRC information block can include one or more RRC information blocks.

[0100] As an example, an RRC information block may not include any RRC information blocks, but only include at least one parameter.

[0101] As an example, the radio bearer includes at least a signaling radio bearer and a data radio bearer.

[0102] As an example, the radio bearer is a service or service interface provided by the PDCP sublayer to a higher layer.

[0103] As a sub - example of this example, the higher layer includes one of the RRC sublayer, NAS, and SDAP layer.

[0104] As an example, the signaling radio bearer is a service or service interface provided by the PDCP to a higher layer.

[0105] As a sub - example of this example, the higher layer includes at least the former of the RRC sublayer and NAS.

[0106] As an example, the data radio bearer is a service or service interface provided by the PDCP to a higher layer.

[0107] As a sub - example of this example, the higher layer includes at least the former of the SDAP layer and NAS.

[0108] As an example, the RLC bearer is a service or service interface provided by the RLC sublayer to the PDCP sublayer.

[0109] As an example, when the terminal establishes an RRC connection with the network, the terminal enters the RRC connected state.

[0110] As a sub - example of this example, the network is a radio access network (RAN).

[0111] As an embodiment, when the terminal does not establish an RRC connection with the network, the terminal is in the RRC idle state.

[0112] As a sub - embodiment of this embodiment, the network is a radio access network (RAN).

[0113] As an embodiment, when the RRC connection established by the terminal with the network is suspended, the terminal enters the RRC inactive state.

[0114] As a sub - embodiment of this embodiment, the network is a radio access network (RAN).

[0115] As an embodiment, different functions are supported in different RRC states.

[0116] As an embodiment, only very limited functions are supported in the non - RRC connected state.

[0117] As an embodiment, the non - RRC connected state is or includes the RRC idle state.

[0118] As an embodiment, the non - RRC connected state is or includes the RRC inactive state.

[0119] As an embodiment, the terminal is not in the limited service mode.

[0120] As an embodiment, the method proposed in this application and the based scenario are not for emergency services.

[0121] As an embodiment, the first signaling is RRC signaling.

[0122] As an embodiment, the first signaling is higher - layer signaling.

[0123] As an embodiment, the advantage of the first signaling being RRC signaling is that, compared with MAC CE (control element) and DCI (downlink control information), RRC signaling is more reliable and more secure.

[0124] As an embodiment, those skilled in the art should understand that the terminal can send feedback on the first signaling.

[0125] As an embodiment, the first signaling is RRCReconfiguration.

[0126] As an embodiment, the first signaling is sent through SRB1 (signaling radio bearer 1).

[0127] As an example, the first signaling includes NAS signaling.

[0128] As an example, the advantage of configuring the at least one NCC by the core network is that it can be not affected by the base station. For example, when performing handover, the base station needs to be changed, which improves security.

[0129] As an example, when the first signaling is RRC signaling, the RRC signaling can carry information from the core network in the form of a container, for example, and the information from the core network indicates the at least one NCC.

[0130] As an example, when the first signaling is RRC signaling, the at least one NCC carried by the RRC signaling is received by the base station from the core network.

[0131] As an example, the at least one NCC includes 1 NCC.

[0132] As an example, the at least one NCC includes no more than 8 NCCs.

[0133] As an example, the at least one NCC includes 7 NCCs.

[0134] As an example, the at least one NCC includes 2 NCCs.

[0135] As an example, the first signaling including the at least one NCC includes: the first signaling indicates each of the at least one NCCs.

[0136] As an example, the first signaling including the at least one NCC includes: the first signaling indicates K, where K is K NCCs not used by the terminal.

[0137] As an example, those skilled in the art should understand what an NCC is.

[0138] As an example, the AS layer security context of the terminal stores the at least one NCC.

[0139] As an example, the AS layer security context of the terminal stores keys and at least one candidate NH parameter.

[0140] As an example, the AS layer security context of the terminal stores the identifier of the encryption algorithm, the security capabilities of the terminal, security policies, and the user plane security activation status.

[0141] As an example, the AS layer security context of the terminal stores a counter.

[0142] As a sub - embodiment of this embodiment, the counter is used to guard against replay attacks.

[0143] As an embodiment, the core network, such as the AMF (Access Mobility Function), stores the at least one NCC and at least one candidate NH parameter.

[0144] As an embodiment, any one of the at least one NCCs identifies a candidate NH parameter.

[0145] As an embodiment, any one of the at least one NCCs corresponds to at least one candidate NH.

[0146] As an embodiment, any one of the at least one NCCs corresponds to one candidate NH respectively.

[0147] As an embodiment, the first signaling indicates that the at least one NCC includes indicating the at least one NCC using a list or a bitmap.

[0148] As an embodiment, any one of the at least one NCCs corresponding to at least one candidate NH (Next Hop) parameter includes: any one of the at least one NCCs identifies a candidate NH parameter.

[0149] As an embodiment, any one of the at least one NCCs corresponding to at least one candidate NH (Next Hop) parameter includes: there is a one - to - one correspondence between any one of the at least one NCCs and a candidate NH parameter.

[0150] As an embodiment, any one of the at least one NCCs corresponding to at least one candidate NH (Next Hop) parameter includes: there are as many candidate NH parameters as there are NCCs.

[0151] As an embodiment, determining the first NH parameter includes: the candidate NH parameter corresponding to the first NCC is the first NH parameter.

[0152] As an embodiment, determining the first NH parameter includes: the candidate NH parameter corresponding to the first NCC is the first NH parameter.

[0153] As an embodiment, the at least one candidate NH parameter does not need to be indicated by the base station to the terminal.

[0154] As an embodiment, the at least one NCC includes a plurality of NCCs.

[0155] As an example, a typical scenario targeted by the present application is that the at least one NCC includes multiple NCCs.

[0156] As an example, the at least one candidate configuration includes multiple candidate configurations.

[0157] As an example, each of the at least one candidate configurations is for a candidate target cell for LTM (L1L2 triggered mobility).

[0158] As an example, any one of the at least one candidate configurations is for one LTM candidate target cell.

[0159] As an example, each of the at least one candidate configurations is for a candidate target cell for CHO (conditional handover).

[0160] As an example, any one of the at least one candidate configurations is for one CHO candidate target cell.

[0161] As an example, the candidate target cell is a candidate target cell for handover.

[0162] As an example, the candidate target cell for handover is for LTM handover.

[0163] As an example, the candidate target cell for handover is for CHO handover.

[0164] As an example, the candidate target cell for handover is for CPAC (conditional PSCell adding or modification) handover.

[0165] As an example, after receiving a handover instruction, the terminal may execute the first candidate configuration among the at least one candidate configurations, which is the prior art in the art.

[0166] As an example, when the execution condition associated with the first candidate configuration is satisfied, the execution of the first candidate configuration among the at least one candidate configurations is triggered.

[0167] As an example, the execution condition associated with the first candidate configuration is configured by the first signaling.

[0168] As an example, the execution condition associated with the first candidate configuration includes: the quality of the neighboring cell is better than a certain threshold, the neighboring cell is better than the serving cell by a certain threshold, and so on.

[0169] As an embodiment, when a link failure triggers RRC connection reconstruction, and the cell selected in the RRC connection reconstruction is the candidate target cell configured by the first candidate configuration, trigger the execution of the first candidate configuration among the at least one candidate configuration.

[0170] As an embodiment, the terminal selects a cell according to the signal quality.

[0171] As an embodiment, the terminal selects a cell according to the priority.

[0172] As an embodiment, the terminal selects a cell according to the service connection situation.

[0173] As an embodiment, accompanying the execution of the first candidate configuration among the at least one candidate configuration, selecting a first NCC from the at least one NCC includes: accompanying the execution of the first candidate configuration among the at least one candidate configuration triggers the selection of a first NCC from the at least one NCC.

[0174] As an embodiment, accompanying the execution of the first candidate configuration among the at least one candidate configuration, selecting a first NCC from the at least one NCC includes: accompanying the execution of the first candidate configuration among the at least one candidate configuration includes selecting a first NCC from the at least one NCC.

[0175] As an embodiment, accompanying the execution of the first candidate configuration among the at least one candidate configuration, selecting a first NCC from the at least one NCC includes: accompanying the execution of the first candidate configuration among the at least one candidate configuration and selecting a first NCC from the at least one NCC are executed simultaneously.

[0176] As an embodiment, accompanying the execution of the first candidate configuration among the at least one candidate configuration, selecting a first NCC from the at least one NCC includes: accompanying the execution of the first candidate configuration among the at least one candidate configuration and selecting a first NCC from the at least one NCC are executed successively.

[0177] As an embodiment, the first key is a key used at the AS layer.

[0178] As an embodiment, the first key is K NG-RAN 。

[0179] As an embodiment, the first key is K gNB 。

[0180] As an embodiment, the first key is K gNB 。

[0181] As an embodiment, the first key is or is used to derive a key for encryption or integrity protection of the control plane.

[0182] As an embodiment, the first key is or is used to derive a key for encryption or integrity protection of the user plane.

[0183] As an embodiment, the first key is K RRCenc , K RRCint , K UPint , K UPenc among them.

[0184] As an embodiment, selecting a first NCC from the at least one NCC includes: the terminal randomly selects an unused NCC from the at least one NCC as the first NCC.

[0185] As an embodiment, selecting a first NCC from the at least one NCC includes: the terminal selects the NCC with the smallest value among the unused NCCs from the at least one NCC according to the value of the NCC as the first NCC.

[0186] As an embodiment, selecting a first NCC from the at least one NCC includes: the terminal selects the first unused NCC from the at least one NCC according to the order of the NCCs in the at least one NCC as the first NCC.

[0187] As an embodiment, selecting the first NCC from the at least one NCC includes: selecting an unused NCC from the at least one NCC as the first NCC.

[0188] As a sub - embodiment of this embodiment, the terminal selects an unused NCC from the at least one NCC as the first NCC according to an internal algorithm.

[0189] As a sub - embodiment of this embodiment, the terminal selects an unused NCC from the at least one NCC as the first NCC according to the priority.

[0190] As a sub - embodiment of this embodiment, the first signaling indicates the at least one NCC through a list.

[0191] As an embodiment, the NCC is a counter of the NH parameter, and any NCC identifies or corresponds to an NH parameter.

[0192] As an embodiment, the first NCC is a counter of NH.

[0193] As an embodiment, the first NCC identifies an NH.

[0194] As an embodiment, the at least one NCC does not exceed 8.

[0195] As an embodiment, the terminal itself selects the first NCC from the at least one NCC.

[0196] As an embodiment, the first NCC is fresh.

[0197] As an embodiment, the first NH parameter is fresh.

[0198] As an embodiment, the network does not indicate the correspondence between the at least one NCC and the candidate configuration in the at least one candidate configuration.

[0199] As an embodiment, the first signaling is an RRC message.

[0200] As an embodiment, the first signaling includes multiple RRC messages.

[0201] As an embodiment, the multiple RRC messages are sent at different times.

[0202] As an embodiment, the NAS signaling included in the first signaling indicates the at least one NCC.

[0203] As an embodiment, the AS signaling included in the first signaling indicates the at least one NCC.

[0204] As an embodiment, the at least one candidate configuration is generated by the base station.

[0205] As an embodiment, one of the candidate target cells is a target cell for handover.

[0206] As an embodiment, one of the candidate target cells is a SpCell.

[0207] As an embodiment, the at least one NCC includes at most 8 NCCs.

[0208] As an embodiment, the at least one NCC includes at least 2 NCCs.

[0209] As an embodiment, the execution of the first candidate configuration in the at least one candidate configuration depends on the first condition being met. The first condition is receiving a second signaling, the cell selected when the T311 timer is running is the candidate target cell configured by the first candidate configuration, and one of the condition events associated with the first candidate configuration is satisfied;

[0210] Among them, the second signaling indicates the first candidate configuration.

[0211] As an embodiment, the second signaling is a MAC CE.

[0212] As an embodiment, the second signaling is an LTM signaling.

[0213] As an embodiment, the start condition of the T311 timer includes initiating RRC connection reestablishment.

[0214] As an embodiment, the stop condition of the T311 timer includes: selecting a suitable cell.

[0215] As an embodiment, the expiration of the T311 timer triggers entry into the RRC idle state.

[0216] As an embodiment, the conditional event associated with the first candidate configuration is a conditional measurement event.

[0217] As an embodiment, if the first candidate configuration is associated with a conditional event, the application of the first candidate configuration is conditional.

[0218] As an embodiment, if the first candidate configuration is associated with a conditional event, the application of the first candidate configuration is CHO.

[0219] As an embodiment, if the first candidate configuration is associated with a conditional event, the application of the first candidate configuration is conditional LTM.

[0220] As an embodiment, if the first candidate configuration is associated with a conditional event, the application of the first candidate configuration is conditional CPAC.

[0221] As an embodiment, the conditional event associated with the first candidate configuration is an event for conditional handover or an event for conditional LTM.

[0222] As an embodiment, the event for LTM includes one of Event LTM2, Event LTM3, Event LTM4, and Event LTM5.

[0223] As an embodiment, the event for LTM includes one of Conditional Event LTM2, Conditional Event LTM3, Conditional Event LTM4, and Conditional Event LTM5.

[0224] As an embodiment, selecting a first NCC from the at least one NCC includes: selecting an unused NCC from the at least one NCC as the first NCC.

[0225] As an embodiment, the terminal arbitrarily selects one of the unused NCCs from the at least one NCC as the first NCC.

[0226] As an embodiment, the terminal selects the one with the smallest number from the unused NCCs in the at least one NCC as the first NCC.

[0227] As an embodiment, the first message sends the first NCC in plain text.

[0228] As an embodiment, at least part of the content in the first message is encrypted.

[0229] As a sub - embodiment of this embodiment, the encryption is performed by AS encryption.

[0230] As an embodiment, the header of the first message includes the first NCC.

[0231] As a sub - embodiment of this embodiment, the header of the first message is one of a MAC header, an RLC header, and a PDCP header.

[0232] As an embodiment, the MAC CE included in the first message indicates the first NCC.

[0233] As an embodiment, the advantage of transmitting the first NCC in plain text is that it is beneficial for the target cell to determine the NH parameter when the key has not been obtained / derived, thereby determining the AS key and reducing the delay of configuring the key.

[0234] As an embodiment, the first message includes a first sub - message, and the first sub - message is uplink control information or a MAC header or a MAC CE.

[0235] As a sub - embodiment of this embodiment, the first sub - message is transmitted in plain text.

[0236] As an embodiment, the first message includes a second sub - message, and the first sub - message is an RRC message.

[0237] As a sub - embodiment of this embodiment, the second sub - message is not transmitted in plain text.

[0238] As an embodiment, the first message includes a first container, the first container carries the first NCC, and the key used by the first container is maintained by the source cell of the terminal.

[0239] As described above, the first container carries a first PDCP SDU, and the key used by the first container is the key used by the first PDCP SDU.

[0240] As an embodiment, the key used by the first PDCP SDU is the key used in the PDCP sublayer.

[0241] As an embodiment, the content in the first container is encrypted.

[0242] As an embodiment, the key used for the content in the first container is not the key used by the candidate target cell targeted by the first candidate configuration.

[0243] As an embodiment, the candidate target cell targeted by the first candidate configuration cannot decrypt the content of the first container.

[0244] As an embodiment, the content in the first container is decrypted by the source cell.

[0245] As an embodiment, after decrypting the content of the first container, the source cell of the terminal configures a key for the candidate target cell targeted by the first candidate configuration.

[0246] As an embodiment, the advantages of the above method include: more secure, and there is no need to configure too many keys for candidate cells in advance.

[0247] As an embodiment, the first message includes a second container, the first container carries the first NCC, and the key used by the second container is maintained by the core network.

[0248] As described above, the second container carries a first PDCP SDU, and the key used by the second container is the key used by the first PDCP SDU.

[0249] As an embodiment, the key used by the first PDCP SDU is the key used in the PDCP sublayer.

[0250] As an embodiment, the content in the second container is encrypted.

[0251] As an embodiment, the key used for the content in the second container is not the key used by the candidate target cell targeted by the first candidate configuration.

[0252] As an embodiment, the candidate target cell targeted by the first candidate configuration cannot decrypt the content of the second container.

[0253] As an example, the content in the second container is decrypted by the core network.

[0254] As an example, after the core network of the terminal decrypts the content of the second container, it configures a key for the candidate target cell targeted by the first candidate configuration.

[0255] As an example, the advantages of the above method include: being more secure, not requiring excessive key configuration for candidate cells in advance, and having a relatively small impact on the radio access network.

[0256] Example 2

[0257] Embodiment 2 exemplifies a schematic diagram of a network architecture according to the present application, as shown in the appendix Figure 2 as follows.

[0258] Appendix Figure 2A diagram illustrating the network architecture 200 of 5G NR, LTE (Long-Term Evolution), and LTE-A (Long-Term Evolution Advanced) systems. The 5G NR or LTE network architecture 200 may be referred to as 5GS (5G System) / EPS (Evolved Packet System) 200 or some other suitable term. The 5GS / EPS 200 may include one or more UEs (User Equipment) 201, NG-RAN (Next Generation Radio Access Network) 202, 5GC (5G Core Network) / EPC (Evolved Packet Core) 210, HSS (Home Subscriber Server) / UDM (Unified Data Management) 220, and Internet services 230. The 5GS / EPS may be interconnected with other access networks, but these entities / interfaces are not shown for simplicity. As shown, the 5GS / EPS provides packet-switched services. However, those skilled in the art will readily understand that the various concepts presented throughout this application can be extended to networks that provide circuit-switched services or other cellular networks. The NG-RAN includes NR Node B (gNB) 203 and other gNBs 204. The gNB 203 provides user and control plane protocol termination towards the UE 201. The gNB 203 may be connected to other gNBs 204 via the Xn interface (e.g., backhaul). The gNB 203 may also be referred to as a base station, base transceiver station, radio base station, radio transceiver, transceiver function, basic service set (BSS), extended service set (ESS), TRP (Transmit Receive Point), or some other suitable term. The gNB 203 provides an access point to the 5GC / EPC 210 for the UE 201. Examples of UEs 201 include cellular phones, smartphones, Session Initiation Protocol (SIP) phones, laptop computers, personal digital assistants (PDAs), satellite radios, non-terrestrial base station communications, satellite mobile communications, global positioning systems, multimedia devices, video devices, digital audio players (e.g., MP3 players), cameras, game consoles, drones, aircraft, narrowband Internet of Things devices, machine type communication devices, land vehicles, automobiles, wearable devices, or any other similar functional devices. Those skilled in the art may also refer to the UE 201 as a mobile station, subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other suitable term.gNB203 is connected to 5GC / EPC210 via the S1 / NG interface. 5GC / EPC210 includes MME (Mobility Management Entity) / AMF (Authentication Management Field) / SMF (Session Management Function) 211, other MME / AMF / SMF 214, S-GW (Service Gateway) / UPF (User Plane Function) 212, and P-GW (Packet Date Network Gateway) / UPF 213. MME / AMF / SMF 211 is a control node that processes the signaling between UE201 and 5GC / EPC210. Generally, MME / AMF / SMF 211 provides bearer and connection management. All user IP (Internet Protocal) packets are transmitted through S-GW / UPF 212, and S-GW / UPF 212 itself is connected to P-GW / UPF 213. The P-GW provides UE IP address allocation and other functions. P-GW / UPF 213 is connected to the Internet service 230. The Internet service 230 includes operator-corresponding Internet protocol services, specifically including the Internet, intranet, IMS (IP Multimedia Subsystem), and packet-switched streaming services.

[0259] As an embodiment, the terminal in this application is UE201.

[0260] As an embodiment, the base station of the second node in this application is gNB203.

[0261] As an embodiment, the radio link from the UE201 to the NR node B is an uplink.

[0262] As an embodiment, the radio link from the NR node B to the UE201 is a downlink.

[0263] As an embodiment, the UE201 includes a mobile phone.

[0264] As an embodiment, the UE201 is a dedicated device or special equipment with communication functions.

[0265] As an embodiment, the gNB203 is a Micro Cell base station.

[0266] As an example, the gNB 203 is a pico cell base station.

[0267] As an example, the gNB 203 is a base station used in a home network.

[0268] As an example, the gNB 203 is a base station used in a private network.

[0269] As an example, the gNB 203 is a base station used in an enterprise network.

[0270] Example 3

[0271] Example 3 shows a schematic diagram of an example of a radio protocol architecture for a user plane and a control plane according to the present application, as shown in the appendix Figure 3 as follows. Figure 3 It is a schematic diagram illustrating an example of a radio protocol architecture for a user plane 350 and a control plane 300. Figure 3Show the radio protocol architecture of the control plane 300 for a terminal (UE, gNB) and a second node (gNB, UE), or between two UEs, with three layers: Layer 1, Layer 2, and Layer 3. Layer 1 (L1 layer) is the lowest layer and implements various PHY (Physical Layer) signal processing functions. Layer 1 will be referred to as PHY 301 in this text. Layer 2 (L2 layer) 305 is above PHY 301 and is responsible for the link between the terminal and the second node and between two UEs through PHY 301. Layer 2 305 includes a MAC (Medium Access Control) sublayer 302, an RLC (Radio Link Control) sublayer 303, and a PDCP (Packet Data Convergence Protocol) sublayer 304, and these sublayers terminate at the second node. The PDCP sublayer 304 provides multiplexing between different radio bearers and logical channels. The PDCP sublayer 304 also provides security by encrypting data packets and provides handover support for the terminal between the second nodes. The RLC sublayer 303 provides segmentation and reassembly of upper layer data packets, retransmission of lost data packets, and reordering of data packets to compensate for disordered reception due to HARQ. The MAC sublayer 302 provides multiplexing between logical and transport channels. The MAC sublayer 302 is also responsible for allocating various radio resources (e.g., resource blocks) in a cell between terminals. The MAC sublayer 302 is also responsible for HARQ operations. The RRC (Radio Resource Control) sublayer 306 in Layer 3 (L3 layer) of the control plane 300 is responsible for obtaining radio resources (i.e., radio bearers) and configuring the lower layers using RRC signaling between the second node and the terminal. The PC5-S (PC5 Signaling Protocol) sublayer 307 is responsible for handling the signaling protocol of the PC5 interface. The radio protocol architecture of the user plane 350 includes Layer 1 (L1 layer) and Layer 2 (L2 layer). For the radio protocol architecture of the terminal and the second node in the user plane 350, the corresponding layers and sublayers in the control plane 300 are generally the same for the physical layer 351, the PDCP sublayer 354 in the L2 layer 355, the RLC sublayer 353 in the L2 layer 355, and the MAC sublayer 352 in the L2 layer 355, but the PDCP sublayer 354 also provides header compression for upper layer data packets to reduce radio transmission overhead.The L2 layer 355 in the user plane 350 also includes an SDAP (Service Data Adaptation Protocol) sub-layer 356. The SDAP sub-layer 356 is responsible for the mapping between QoS flows and data radio bearers (DRBs) to support service diversity. The SRB can be regarded as a service or interface provided by the PDCP sub-layer to higher layers, such as the RRC sub-layer. In the NR system, the SRB includes SRB1, SRB2, and SRB3, which are respectively used to transmit different types of control signaling. The SRB is a bearer between the UE and the access network and is used to transmit control signaling including RRC signaling between the UE and the access network. SRB1 is of special significance to the UE. After each UE establishes an RRC connection, there will be an SRB1 for transmitting RRC signaling. Most of the signaling is transmitted through SRB1. If SRB1 is interrupted or unavailable, the UE must perform RRC reconstruction. SRB2 is generally only used to transmit NAS signaling or signaling related to security. The UE may not be configured with SRB3. Except for emergency services, the UE must establish an RRC connection with the network to perform subsequent communication. Although not shown, the terminal may have several upper layers above the L2 layer 355. In addition, it also includes a network layer (e.g., IP layer) terminated at the P-GW on the network side and an application layer terminated at the other end of the connection (e.g., a remote UE, a server, etc.). The protocol layer can also be referred to as a protocol sub-layer. Attached. Figure 3 The shown is a general protocol layer structure, and the nodes used in this application may lack some protocol layers.

[0272] As an example, attached Figure 3 The radio protocol architecture in is applicable to the terminal described in this application.

[0273] As an example, attached Figure 3 The radio protocol architecture in is applicable to the second node described in this application.

[0274] As an example, at least one candidate configuration in this application is generated in RRC306.

[0275] As an example, the first signaling in this application is generated in RRC306 or NAS.

[0276] As an example, the second signaling in this application is generated in MAC304.

[0277] As an example, the first PDCP SDU in this application is generated in NAS.

[0278] As an example, the first message in this application is generated in RRC306.

[0279] Example 4

[0280] Example 4 shows a schematic diagram of a first communication device and a second communication device according to an embodiment of the present application, as shown in the appendix Figure 4 as shown Figure 4 is a block diagram of a first communication device 450 and a second communication device 410 that communicate with each other in an access network

[0281] The first communication device 450 includes a controller / processor 459, a memory 460, a data source 467, a transmitting processor 468, a receiving processor 456, and optionally may further include a multi-antenna transmitting processor 457, a multi-antenna receiving processor 458, a transmitter / receiver 454, and an antenna 452

[0282] The second communication device 410 includes a controller / processor 475, a memory 476, a receiving processor 470, a transmitting processor 416, and optionally may further include a multi-antenna receiving processor 472, a multi-antenna transmitting processor 471, a transmitter / receiver 418, and an antenna 420

[0283] In the transmission from the second communication device 410 to the first communication device 450, at the second communication device 410, upper layer data packets from the core network are provided to the controller / processor 475. The controller / processor 475 implements the functionality of the L2 (Layer-2) layer. In the transmission from the second communication device 410 to the first communication device 450, the controller / processor 475 provides header compression, encryption, packet segmentation and reordering, multiplexing between logical and transport channels, and radio resource allocation for the first communication device 450 based on various priority metrics. The controller / processor 475 is also responsible for retransmission of lost packets and signaling to the first communication device 450. The transmit processor 416 and the multi-antenna transmit processor 471 implement various signal processing functions for the L1 layer (i.e., the physical layer). The transmit processor 416 implements encoding and interleaving to facilitate forward error correction (FEC) at the second communication device 410, and mapping of signal constellations based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), M-quadrature amplitude modulation (M-QAM)). The multi-antenna transmit processor 471 performs digital space precoding on the encoded and modulated symbols, including codebook-based precoding and non-codebook-based precoding, and beamforming processing, to generate one or more spatial streams. The transmit processor 416 then maps each spatial stream to subcarriers, multiplexes with reference signals (e.g., pilots) in the time domain and / or frequency domain, and then uses the inverse fast Fourier transform (IFFT) to generate a physical channel carrying a time-domain multi-carrier symbol stream. Subsequently, the multi-antenna transmit processor 471 performs transmit analog precoding / beamforming operations on the time-domain multi-carrier symbol stream. Each transmitter 418 converts the baseband multi-carrier symbol stream provided by the multi-antenna transmit processor 471 into a radio frequency stream and then provides it to different antennas 420.

[0284] In the transmission from the second communication device 410 to the first communication device 450, at the first communication device 450, each receiver 454 receives signals via its respective antenna 452. Each receiver 454 recovers the information modulated onto the radio frequency carrier, and converts the radio frequency stream into a baseband multi-carrier symbol stream and provides it to the receive processor 456. The receive processor 456 and the multi-antenna receive processor 458 perform various signal processing functions of the L1 layer. The multi-antenna receive processor 458 performs receive analog precoding / beamforming operations on the baseband multi-carrier symbol stream from the receivers 454. The receive processor 456 uses the fast Fourier transform (FFT) to convert the baseband multi-carrier symbol stream after the receive analog precoding / beamforming operations from the time domain to the frequency domain. In the frequency domain, the physical layer data signal and the reference signal are demultiplexed by the receive processor 456, where the reference signal will be used for channel estimation, and the data signal recovers any spatial streams destined for the first communication device 450 after multi-antenna detection in the multi-antenna receive processor 458. The symbols on each spatial stream are demodulated and recovered in the receive processor 456, and soft decisions are generated. Subsequently, the receive processor 456 decodes and de-interleaves the soft decisions to recover the upper layer data and control signals transmitted by the second communication device 410 on the physical channel. Subsequently, the upper layer data and control signals are provided to the controller / processor 459. The controller / processor 459 performs the functions of the L2 layer. The controller / processor 459 may be associated with a memory 460 that stores program code and data. The memory 460 may be referred to as a computer-readable medium. In the transmission from the second communication device 410 to the second communication device 450, the controller / processor 459 provides demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, control signal processing to recover upper layer data packets from the core network. Subsequently, the upper layer data packets are provided to all protocol layers above the L2 layer. Various control signals may also be provided to the L3 for L3 processing.

[0285] In the transmission from the first communication device 450 to the second communication device 410, at the first communication device 450, a data source 467 is used to provide upper layer data packets to a controller / processor 459. The data source 467 represents all protocol layers above the L2 layer. Similar to the transmit function described at the second communication device 410 in the transmission from the second communication device 410 to the first communication device 450, the controller / processor 459 implements header compression, encryption, packet segmentation and reordering, and multiplexing between logical and transport channels based on radio resource allocation, and implements L2 layer functions for the user plane and the control plane. The controller / processor 459 is also responsible for retransmission of lost packets and signaling to the second communication device 410. A transmit processor 468 performs modulation mapping and channel coding processing. A multi-antenna transmit processor 457 performs digital multi-antenna spatial precoding, including codebook-based precoding and non-codebook-based precoding, and beamforming processing. Subsequently, the transmit processor 468 modulates the generated spatial streams into multi-carrier / single-carrier symbol streams, which are provided to different antennas 452 via a transmitter 454 after an analog precoding / beamforming operation in the multi-antenna transmit processor 457. Each transmitter 454 first converts the baseband symbol stream provided by the multi-antenna transmit processor 457 into a radio frequency symbol stream and then provides it to the antenna 452.

[0286] In the transmission from the first communication device 450 to the second communication device 410, the functions at the second communication device 410 are similar to the receive function described at the first communication device 450 in the transmission from the second communication device 410 to the first communication device 450. Each receiver 418 receives radio frequency signals through its corresponding antenna 420, converts the received radio frequency signals into baseband signals, and provides the baseband signals to a multi-antenna receive processor 472 and a receive processor 470. The receive processor 470 and the multi-antenna receive processor 472 jointly implement L1 layer functions. A controller / processor 475 implements L2 layer functions. The controller / processor 475 may be associated with a memory 476 that stores program code and data. The memory 476 may be referred to as a computer-readable medium. In the transmission from the first communication device 450 to the second communication device 410, the controller / processor 475 provides demultiplexing between transport and logical channels, packet reassembly, decryption, header decompression, and control signal processing to recover upper layer data packets from the UE 450. The upper layer data packets from the controller / processor 475 may be provided to the core network.

[0287] As an example, the first communication device 450 includes: at least one processor and at least one memory, the at least one memory including computer program code; the at least one memory and the computer program code are configured to be used together with the at least one processor, and the first communication device 450 is at least configured to: receive first signaling, the first signaling including at least one NCC (Next Hop Chain Counter) and at least one candidate configuration; wherein any one of the at least one candidate configurations is for a candidate target cell; execute a first candidate configuration among the at least one candidate configurations; in association with the execution of the first candidate configuration among the at least one candidate configurations, select a first NCC from the at least one NCCs, wherein the first NCC corresponds to a first NH parameter; derive a first key according to the first NH parameter; and as a response to the completion of the execution of the first candidate configuration, send a first message, the first message indicating the first NCC.

[0288] As an example, the first communication device 450 includes: a memory storing a computer-readable instruction program, the computer-readable instruction program generating actions when executed by at least one processor, the actions including: receiving first signaling, the first signaling including at least one NCC (Next Hop Chain Counter) and at least one candidate configuration; wherein any one of the at least one candidate configurations is for a candidate target cell; execute a first candidate configuration among the at least one candidate configurations; in association with the execution of the first candidate configuration among the at least one candidate configurations, select a first NCC from the at least one NCCs, wherein the first NCC corresponds to a first NH parameter; derive a first key according to the first NH parameter; and as a response to the completion of the execution of the first candidate configuration, send a first message, the first message indicating the first NCC.

[0289] As an example, the first communication device 450 corresponds to the terminal in the present application.

[0290] As an example, the second communication device 410 corresponds to the second node in the present application.

[0291] As an example, the first communication device 450 is a UE.

[0292] As an example, the first communication device 450 is a mobile phone.

[0293] As an example, the second communication device 450 is a relay.

[0294] As an example, the second communication device 410 is a base station.

[0295] As an example, the receiver 454 (including the antenna 452), the receiving processor 456, and the controller / processor 459 are used to receive the first signaling in this application.

[0296] As an example, the receiver 454 (including the antenna 452), the receiving processor 456, and the controller / processor 459 are used to receive the second signaling in this application.

[0297] As an example, the transmitter 454 (including the antenna 452), the transmitting processor 468, and the controller / processor 459 are used to send the first PDCP SDU in this application.

[0298] As an example, the transmitter 454 (including the antenna 452), the transmitting processor 468, and the controller / processor 459 are used to send the first message in this application.

[0299] Example 5

[0300] Embodiment 5 exemplifies a wireless signal transmission flowchart according to an embodiment of this application, as shown in the appendix. Figure 5 In the appendix, U01 corresponds to the terminal of this application. It should be specifically noted that the order in this example does not limit the signal transmission order and implementation order in this application, and the steps within F51 and F52 are optional. Figure 5 Among them, for, in step S5101, receive the first signaling; in step S5102, receive the second signaling; in step S5103, execute the first candidate configuration in at least one candidate configuration; in step S5104, send the first message; in step S5105, determine the first NCC in at least one NCC; in step S5106, derive the first key according to the first NH parameter; in step S5107, send the first PDCP SDU.

[0301] For Terminal U01 , in step S5201, send the first signaling; in step S5202, send the second signaling.

[0302] For Second Node U02 , in step S5201, send the first signaling; in step S5202, send the second signaling.

[0303] As an example, the second node U02 is the base station corresponding to the PCell of the terminal U01.

[0304] As an example, the second node U02 is the control unit associated with the PCell of the terminal U01.

[0305] As an example, the second node U02 is the serving cell of the terminal or the base station corresponding to the serving cell.

[0306] As an example, the second node U02 belongs to the cellular network.

[0307] As an example, the second node U02 corresponds to the source cell in a handover.

[0308] As an example, step S5102 is not earlier than step S5101.

[0309] As an example, step S5103 is later than step S5102.

[0310] As an example, step S5104 is later than step S5103.

[0311] As an example, step S5105 is later than step S5104.

[0312] As an example, step S5106 is later than step S5105.

[0313] As an example, step S5104 is later than step S5106.

[0314] As an example, step S5107 is later than step S5104.

[0315] As an example, step S5108 is later than step S5107.

[0316] As an example, when conditional-triggered handover is adopted, step S5102 can be omitted.

[0317] As an example, step S5103 is part of the cell handover.

[0318] As an example, step S5104 determines or indicates to the network the success of the cell handover.

[0319] As an example, the recipient of the first message is the target cell.

[0320] Typically, the target cell is different from the source cell.

[0321] As an example, steps S5105 and S5106 belong to the cell handover process.

[0322] As an example, steps S5105 and S5106 are executed after the cell handover process is completed.

[0323] As an example, the first PDCP SDU is encrypted using the first key or a key derived from the first key.

[0324] As an example, at the PDCP sublayer, the first PDCP SDU is encrypted and then encapsulated in a PDCP PDU.

[0325] As an example, the second message is sent after the next handover is completed.

[0326] As an example, the second message indicates the completion of the next handover.

[0327] As an example, before sending the second message, the terminal U01 executes the second candidate configuration among the at least one candidate configuration; along with the execution of the second candidate configuration among the at least one candidate configuration, a second NCC is selected from the at least one NCC, where the second NCC corresponds to a second NH parameter; a second key is derived according to the second NH parameter;

[0328] As an example, the terminal U01 sends a second message as a response to the completion of the execution of the second candidate configuration, and the second message indicates the second NCC.

[0329] As an example, the second NCC is different from the first NCC.

[0330] As an example, after the first message is sent and before the terminal U01 executes the second candidate configuration among the at least one candidate configuration, the network does not need to modify or reconfigure the at least one candidate configuration.

[0331] As an example, between the execution of the first candidate configuration among the at least one candidate configuration and the execution of the second candidate configuration among the at least one candidate configuration, the terminal is not reconfigured or the at least one candidate configuration is not updated.

[0332] As an example, the advantages of the above method are: saving signaling overhead and reducing handover latency.

[0333] As an example, the second key is different from the first key.

[0334] As an example, the second NH parameter is different from the first NH parameter.

[0335] As an example, the second NCC identifies the second NH parameter.

[0336] As an example, the method of deriving the second key according to the second NH parameter is the same as the method of deriving the first key according to the first NH parameter, but the input parameters are different.

[0337] As an example, deriving the second key according to the second NH parameter and deriving the first key according to the first NH parameter use the same key derivation function.

[0338] As an example, executing the second candidate configuration among the at least one candidate configuration may be network - indicated or triggered based on conditions.

[0339] As an example, executing each candidate configuration among the at least one candidate configuration means a cell handover.

[0340] As an example, selecting the second NCC among the at least one NCC includes: selecting an unused NCC among the at least one NCC as the second NCC.

[0341] As an example, the terminal randomly selects an unused one among the unused NCCs in the at least one NCC as the second NCC.

[0342] As an example, the terminal selects the one with the smallest number among the unused NCCs in the at least one NCC as the second NCC.

[0343] As an example, the receiver of the second message is another target cell.

[0344] As an example, the first PDCP SDU is processed at the PDCP sub - layer to generate a PDCP PDU.

[0345] As an example, the processing at the PDCP sub - layer includes encryption using the first key or a key derived from the first key.

[0346] As an example, the processing at the PDCP sub - layer includes integrity protection using the first key or a key derived from the first key.

[0347] As an example, how to derive the key for encrypting the PDCP SDU from the first key is prior art.

[0348] As an example, the first PDCP SDU is RRC signaling.

[0349] As an example, the first PDCP SDU is data, including the PDU of the SDAP sub - layer.

[0350] As an example, both the first key and the second key are AS keys.

[0351] As an example, the first key is K gNB, the key derived from the first key is a key for RRC signaling encryption or integrity protection.

[0352] As an embodiment, the first key is K gNB , the key derived from the first key is a key for data encryption or integrity protection.

[0353] As an embodiment, there is no case where at least one NCC corresponds to multiple candidate NH parameters in the at least one NCC.

[0354] As an embodiment, the first key is used to derive a key for encrypting PDCP SDUs through horizontal key derivation.

[0355] As an embodiment, the second key is used to derive a key for encrypting PDCP SDUs through horizontal key derivation.

[0356] As an embodiment, the first key is K NG-RAN , the first key first derives K gNB , and then the derived K gNB derives the key for encrypting PDCP SDUs.

[0357] As an embodiment, the first key is K gNB , the first key first derives K gNB , and then the derived K gNB derives the key for encrypting PDCP SDUs.

[0358] As an embodiment, the first message includes a first container, the first container carries the first NCC, and the key used by the first container is maintained by the second node U02.

[0359] As an embodiment, the terminal U01 also maintains the key used by the first container.

[0360] As an embodiment, the terminal U01 also maintains the key used by the second container.

[0361] As an embodiment, when the first message sends the first NCC in plaintext, the target cell of the terminal U01 determines the AS key based on the first NCC.

[0362] As an embodiment, the target cell of the terminal U01 determines the AS key based on the first NCC, including: the target cell of the terminal U01 determines the NH parameter according to the first NCC, and then derives the AS key from the NH parameter.

[0363] As an example, the target cell of the terminal U01 determines the AS key by the first NCC, including: the target cell of the terminal U01 indicates the first NCC to the source cell of the terminal U01, the source cell of the terminal U01 determines the NH parameter according to the first NCC, then derives the AS key from the NH parameter, and then indicates the AS key to the target cell of the terminal U01.

[0364] As an example, the target cell of the terminal U01 determines the AS key by the first NCC, including: the target cell of the terminal U01 indicates the first NCC to the source cell of the terminal U01, the source cell of the terminal U01 requests the core network, and then the core network generates the AS key used by the target cell of the terminal U01.

[0365] As an example, the target cell of the terminal U01 determines the AS key by the first NCC, including: the target cell of the terminal U01 indicates the first NCC to the core network of the terminal U01, the core network of the terminal U01 determines the NH parameter according to the first NCC, then derives the AS key from the NH parameter, and then indicates the AS key to the target cell of the terminal U01.

[0366] Example 6

[0367] Example 6 exemplifies a schematic diagram of key generation according to an embodiment of the present application, as shown in the appendix Figure 6 shown.

[0368] Appendix Figure 6 shows key update, especially key update during handover.

[0369] In the appendix Figure 6 K AMF is maintained by the terminal and the core network, and the NAS uplink COUNT is the uplink counter of the NAS layer. K AMF is used to derive the initial K gNB ; with the initial K gNB , when a new K gNB needs to be derived subsequently, it is all derived with the participation of the NH parameter. K gNB Through the key derivation function, parameters such as PCI (physical cell identifier) and downlink frequency (DL frequency) are used as inputs, and K NG-RAN * can be derived, and then a new K gNB . This is called horizontal key derivation. In some cases, such as when handing over between base stations, vertical key derivation is required, including: deriving a new HN parameter, then deriving from the NH parameter, and deriving K NG-RAN * and then deriving a new KgNB 。

[0370] Note that in an evolved network, if the base station is not named gNB, for example, it is named xNB, the name of the key will also change accordingly. For example, K xNB is correspondingly replaced by K xNB . Therefore, in an evolved network, only a simple replacement is needed and the method proposed in this application can still be used. The method proposed in this application is applicable to an evolved network.

[0371] As an example, an NCC is selected. If the difference between this NCC and the existing NCC is more than 1, for example, the current NCC = i, and the newly selected NCC, for example, the first NCC, is equal to mod(i + x, 8), where mod is the modulo operation, then x times of NH parameter derivation need to be performed. For example, if x is equal to 2, then 2 times of NH parameter derivation need to be performed. The NH parameter obtained from the second NH parameter derivation is the required NH parameter, that is, the first NH parameter.

[0372] As an example, a network, including a core network, can instruct the terminal to continuously derive NH parameters until the NH parameter corresponding to the nearest NCC = 0 is obtained. The advantage is that it ensures the synchronization of keys between the terminal and the network.

[0373] Example 7

[0374] Example 7 illustrates a schematic diagram of using the first NH parameter according to an embodiment of this application to derive the first key, as shown in the appendix Figure 7 shown.

[0375] As an example, the first NH parameter derives the first key through a key derivation function.

[0376] As an example, the key derivation function is predefined.

[0377] As an example, the key derivation function is a prior art. For example, reference can be made to Appendix B.2.0 of 3GPP TS 33.220. Hereinafter, it is referred to as the first key derivation function.

[0378] As an example, any NH parameter includes at least 128 bits.

[0379] As an example, any NH parameter is 256 bits.

[0380] As an example, any NH parameter is more than 256 bits.

[0381] As an example, the terminal uses the key provided by the core network, such as K AMF, sequentially export the NH parameters. NCC is the count of the NH parameters. For example, when the current NCC = i, if the terminal needs to use the NH parameter corresponding to the next-next of NCC = i, the terminal needs to first export one NH parameter, and then export the next NH parameter. The NCC corresponding to the next NH parameter is the next-next NCC of NCC = i.

[0382] As a sub - embodiment of this embodiment, the first exported NH parameter is used to export the next NH parameter.

[0383] As a sub - embodiment of this embodiment, the first exported NH parameter is used as the input of the first key derivation function to export the next NH parameter.

[0384] As an embodiment, any NH parameter is an intermediate key.

[0385] As an embodiment, when deriving the first key from the first NH parameter, at least one input parameter is input to the first key derivation function.

[0386] As a sub - embodiment of this embodiment, the at least one input parameter includes: FC = 0x70.

[0387] As a sub - embodiment of this embodiment, the at least one input parameter includes: P0 = cell identifier.

[0388] As a sub - embodiment of this embodiment, the at least one input parameter includes: L0 = the length of the cell identifier.

[0389] As a sub - embodiment of this embodiment, the at least one input parameter includes: P1 = frequency parameter.

[0390] As a sub - embodiment of this embodiment, the at least one input parameter includes: L1 = the length of the frequency parameter.

[0391] As a sub - embodiment of this embodiment, the at least one input parameter includes: the first NH parameter.

[0392] As a sub - embodiment of this embodiment, the at least one input parameter includes: the first identifier.

[0393] As an embodiment, when the input for deriving the first key from the first NH parameter includes the first network identifier, it means that the first NH parameter can generate different keys according to different network identifiers, which is beneficial to increasing the availability of the NH parameter and solving the problem of NCC exhaustion.

[0394] Example 8

[0395] Example 8 exemplifies a schematic diagram of cell handover according to an embodiment of the present application, as shown in the appendix Figure 8 as follows.

[0396] As an embodiment, the appendix Figure 8 shows a cell handover scenario, where cell 1 and cell 3 correspond to CU-1, i.e., control unit 1. For example, cell 1 and cell 3 belong to the same base station; cell 2 corresponds to CU-2. For example, cell 2 belongs to another base station. In the appendix Figure 8 , the terminal hands over from cell 2 to cell 1.

[0397] As an embodiment, the method proposed in the present application is particularly applicable to cell handover between CUs.

[0398] As an embodiment, typically, changing the key is required for cell handover between CUs.

[0399] As an embodiment, both cell 1 and cell 3 are neighboring cells of cell 2 and are also candidate target cells of cell 2.

[0400] As an embodiment, the cell handover includes LTM.

[0401] As an embodiment, the NCC in the at least one NCC is not pre-specified for which candidate cell, or there may be one NCC in the at least one NCC that is for multiple candidate target cells.

[0402] As an embodiment, it is determined by the terminal which target cell the NCC in the at least one NCC is associated with or applied to.

[0403] As an embodiment, the advantage of the above method is to increase flexibility and avoid rapid exhaustion of the NCC.

[0404] As an embodiment, the at least one NCC includes the NCC for cell 1 and the NCC for cell 3.

[0405] As an embodiment, the terminal determines how many times the NH parameter needs to be derived according to the first identifier and the first NCC and determines the first NH parameter from the derived NH parameters. For example, the last NH parameter is determined as the first NH parameter.

[0406] As an embodiment, after the handover, the terminal determines how many times the NH parameter needs to be derived.

[0407] As an embodiment, when the terminal first hands over to, or has never been connected to CU-1 or cell 1, the at least one NCC includes an NCC with a value of 0.

[0408] As a sub - embodiment of this embodiment, the first switch to or never being connected to CU - 1 or cell 1 means after establishing a connection with the current core network or after the most recent authentication.

[0409] As an embodiment, when the terminal performs a handover between CUs, regardless of whether the NCC used in the source cell or the target cell changes, the NH parameter needs to be derived at least once.

[0410] As an embodiment, when the terminal performs a handover between CUs, regardless of whether the NCC used in the source cell or the target cell changes, the NH parameter needs to be derived at least multiple times.

[0411] As an embodiment, when the terminal performs a handover between CUs, regardless of whether the NCC used in the source cell or the target cell changes, the NH parameter needs to be derived more than once at least.

[0412] As an embodiment, when the terminal performs a handover between CUs, if the NCCs used in the source cell and the target cell differ by y, then the NH parameter needs to be derived more than y times at least.

[0413] As an embodiment, the above - mentioned method can well solve the problem that the NCC is easily exhausted during multiple consecutive handovers between CUs.

[0414] As an embodiment, cell 1 can determine the key to be used for communicating with the terminal only after receiving the first message.

[0415] As an embodiment, cell 1 can determine the NCC and the NH parameter after receiving the first message, and then determine the key to be used for communicating with the terminal.

[0416] As an embodiment, the core network and the source cell do not pre - configure the key to the candidate target cell in advance. The advantages of the above - mentioned method include: increased security.

[0417] As an embodiment, the first message indicates how many are available in the remaining one NCC.

[0418] As an embodiment, the first message indicates how many are unavailable in the remaining one NCC.

[0419] As an embodiment, the advantage of the above - mentioned method is that the network can configure a new NCC earlier.

[0420] As an embodiment, the network can instruct the terminal to refresh the used NCC in the at least one NCC.

[0421] As a sub - embodiment of this embodiment, the refresh can be continued to be used.

[0422] As a sub - embodiment of this embodiment, the refresh is for the next round and can be continued to be used.

[0423] As a sub - embodiment of this embodiment, the refresh is that the used NCCs in the at least one NCC are refreshed to correspond to the second NH parameter. Among them, the first NH parameter is derived to obtain the second NH parameter after 8 times or a multiple of 8 times.

[0424] As a sub - embodiment of this embodiment, the network can indicate the refresh through MAC CE or DCI.

[0425] As a sub - embodiment of this embodiment, the network can indicate the refresh through one bit.

[0426] As an embodiment, the advantage of the above method is: it can conveniently and quickly implement the update of the NCC and save signaling overhead.

[0427] Example 9

[0428] Embodiment 9 exemplifies a structural block diagram of a processing device in a terminal according to an embodiment of the present application; as shown in the appendix Figure 9 shown. In the appendix Figure 9 The processing device 900 in the terminal includes a first receiver 901, a first transmitter 902, and a first processor 903.

[0429] In Embodiment 9, the terminal has one or more processors and a memory;

[0430] The memory is coupled to the one or more processors. The memory is used to store computer program code, and the computer program code includes computer instructions. The one or more processors call the computer instructions to enable the terminal to at least execute:

[0431] Receive a first signaling, the first signaling includes at least one NCC (Next Hop Chain Counter) and at least one candidate configuration; wherein, any candidate configuration in the at least one candidate configuration is for a candidate target cell;

[0432] Execute the first candidate configuration in the at least one candidate configuration; along with the execution of the first candidate configuration in the at least one candidate configuration, select a first NCC in the at least one NCC, where the first NCC corresponds to a first NH parameter; derive a first key according to the first NH parameter;

[0433] In response to the execution of the first candidate configuration being completed, send a first message, where the first message indicates the first NCC.

[0434] As an example, the at least one NCC includes multiple NCCs.

[0435] As an example, the execution of the first candidate configuration among the at least one candidate configurations depends on a first condition being met. The first condition is receiving a second signaling, the cell selected when the T311 timer is running is the candidate target cell configured by the first candidate configuration, and one of the conditional events associated with the first candidate configuration is satisfied.

[0436] Among them, the second signaling indicates the first candidate configuration.

[0437] As an example, the conditional event associated with the first candidate configuration is an event for conditional handover or an event for conditional LTM.

[0438] As an example, the first message sends the first NCC in plain text.

[0439] As an example, the first message includes a first container, the first container carries the first NCC, and the key used by the first container is maintained by the terminal source cell.

[0440] As an example, the selection of the first NCC from the at least one NCC includes: selecting an unused NCC from the at least one NCC as the first NCC.

[0441] As an example, the first message indicates the number of unused NCCs in the at least one NCC.

[0442] As an example, the first processor 903 executes the second candidate configuration among the at least one candidate configurations; along with the execution of the second candidate configuration among the at least one candidate configurations, select a second NCC from the at least one NCC, where the second NCC corresponds to a second NH parameter; derive a second key according to the second NH parameter.

[0443] The first processor 903, in response to the execution of the second candidate configuration being completed, sends a second message, where the second message indicates the second NCC.

[0444] As an example, the terminal is a user equipment (UE).

[0445] As an example, the terminal is a terminal supporting large delay spreads.

[0446] As an example, the terminal is a terminal supporting NTN.

[0447] As an example, the terminal is an aircraft.

[0448] As an example, the terminal is a vehicle-mounted terminal.

[0449] As an example, the terminal is a mobile phone.

[0450] As an example, the terminal is a ship.

[0451] As an example, the terminal is an Internet of Things (IoT) terminal.

[0452] As an example, the terminal is a terminal of industrial Internet of Things.

[0453] As an example, the first receiver 901 includes at least one of the antenna 452, receiver 454, reception processor 456, multi-antenna reception processor 458, controller / processor 459, memory 460, or data source 467 in Embodiment 4.

[0454] As an example, the first transmitter 902 includes at least one of the antenna 452, transmitter 454, transmission processor 468, multi-antenna transmission processor 457, controller / processor 459, memory 460, or data source 467 in Embodiment 4.

[0455] Those of ordinary skill in the art can understand that all or part of the steps in the above methods can be completed by instructing relevant hardware through a program, and the program can be stored in a computer-readable storage medium, such as a read-only memory, a hard disk, or an optical disc, etc. Optionally, all or part of the steps of the above embodiments can also be implemented using one or more integrated circuits. Correspondingly, each module unit in the above embodiments can be implemented in a hardware form or in the form of a software function module. This application is not limited to any specific form of the combination of software and hardware. The user equipment, terminal, and UE in this application include, but are not limited to, drones, communication modules on drones, remote control airplanes, aircraft, small airplanes, mobile phones, tablet computers, notebooks, vehicle-mounted communication devices, wireless sensors, network cards, Internet of Things terminals, RFID terminals, NB-IoT terminals, MTC (Machine Type Communication) terminals, eMTC (enhanced MTC) terminals, data cards, network cards, vehicle-mounted communication devices, low-cost mobile phones, low-cost tablet computers, satellite communication devices, ship communication devices, NTN user equipment and other wireless communication devices. The base station or system equipment in this application includes, but is not limited to, macrocell base stations, microcell base stations, home base stations, relay base stations, gNB (NR Node B) NR Node B, TRP (Transmitter Receiver Point), NTN base stations, satellite devices, flight platform devices and other wireless communication devices.

[0456] The present invention may be embodied in other specific forms without departing from its core or essential characteristics. Therefore, the presently disclosed embodiments should in any event be considered as illustrative rather than restrictive. The scope of the invention is determined by the appended claims rather than the foregoing description, and all changes within the meaning and range of equivalents thereof are considered to be included therein.

Claims

1. A method in a terminal, wherein: include: Receive a first signaling, where the first signaling includes at least one NCC (Next Hop Chain Counter) and at least one candidate configuration; wherein any candidate configuration of the at least one candidate configuration is for a candidate target cell; Executing a first candidate configuration among the at least one candidate configuration; accompanying the executing of the first candidate configuration among the at least one candidate configuration, selecting a first NCC among the at least one NCC, wherein the first NCC corresponds to a first NH parameter; deriving a first key according to the first NH parameter; In response to completing the execution of the first candidate configuration, a first message is sent, where the first message indicates the first NCC.

2. The method in the terminal according to claim 1, characterized in that: The at least one NCC includes a plurality of NCCs.

3. The method in the terminal according to claim 1 or 2, characterized in that: The execution of the first candidate configuration in the at least one candidate configuration depends on the first condition being satisfied, the first condition being that the second signaling is received, the cell selected when the T311 timer runs is the candidate target cell configured by the first candidate configuration, and one of the conditional events associated with the first candidate configuration is satisfied. The second signaling indicates the first candidate configuration.

4. The method in the terminal according to claim 3, characterized in that: The conditional event associated with the first candidate configuration is an event for conditional switching or an event for conditional LTM.

5. The method in a terminal according to any one of claims 1 to 4, characterized in that: The first message is sent to the first NCC in plain text.

6. The method in a terminal according to any one of claims 1 to 4, characterized in that: The first message includes a first container, the first container carries the first NCC, and a key used by the first container is maintained by the terminal source cell.

7. The method in a terminal according to any one of claims 1 to 6, characterized in that: The selecting a first NCC from among the at least one NCC includes: selecting an unused NCC from among the at least one NCC as the first NCC.

8. The method in a terminal according to any one of claims 1 to 7, characterized in that: The first message indicates the number of unused NCCs in the at least one NCC.

9. The method in a terminal according to any one of claims 1 to 8, characterized in that: include: executing a second candidate configuration of the at least one candidate configuration; Accompanying the executing of a second candidate configuration in the at least one candidate configuration, selecting a second NCC in the at least one NCC, wherein the second NCC corresponds to a second NH parameter; deriving a second key according to the second NH parameter; In response to completing the execution of the second candidate configuration, a second message is sent, where the second message indicates the second NCC.

10. A terminal, characterized in that: The terminal comprises: one or more processors and memory; The memory is coupled to the one or more processors, and the memory is used to store computer program codes, where the computer program codes include computer instructions. The one or more processors call the computer instructions to enable the terminal to execute the method according to any one of claims 1 to 9.

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