Communication methods and devices

Abstract

The present application relates to communication methods and devices. A method comprises: a terminal sends a first combined registration request to a first core network device by means of an access network device corresponding to a first RAT, wherein the first combined registration request is used for requesting establishing in a core network a context for the terminal under the first RAT and a second RAT.

Description

Communication methods and devices Technical Field

[0001] This application relates to the field of communications, and more specifically, to a communication method and apparatus. Background Technology

[0002] In related technologies, after a terminal accesses the core network through an access network device under a RAT (Radio Access Technology), a registration state is typically maintained for that terminal under a separate RAT. However, with technological advancements, terminals may need to simultaneously access two or more communication systems or networks through two or more RATs. But if a terminal wants to access two or more communication systems or networks separately through two or more RATs, it often requires the terminal to request registration from different communication systems or networks under different RATs. This leads to increased signaling overhead on the air interface and a lack of improvement in communication efficiency. Summary of the Invention

[0003] This application provides a communication method and device.

[0004] This application provides a communication method, including:

[0005] The terminal sends a first merged registration request to the first core network device through the access network device corresponding to the first RAT, wherein the first merged registration request is used to request the establishment of a context for the terminal under the first RAT and the second RAT in the core network.

[0006] This application provides a communication method, including:

[0007] The first core network device receives a first merged registration request from the terminal through the access network device corresponding to the first RAT, wherein the first merged registration request is used to request the establishment of a context for the terminal in the core network under the first RAT and the second RAT.

[0008] This application provides a communication method, including:

[0009] The second core network device receives a second merge registration request from the first core network device, wherein the second merge registration request is used to request the establishment of a context for the terminal under the second RAT.

[0010] This application provides a terminal, including:

[0011] The first communication unit is configured to send a first merged registration request to the first core network device through the access network device corresponding to the first RAT, wherein the first merged registration request is used to request the establishment of a context for the terminal under the first RAT and the second RAT in the core network.

[0012] This application provides a first core network device, including:

[0013] The second communication unit is used to receive a first merged registration request sent by the terminal through the access network device corresponding to the first RAT, wherein the first merged registration request is used to request the establishment of a context for the terminal in the core network under the first RAT and the second RAT.

[0014] This application provides a second core network device, including:

[0015] The third communication unit is used to receive a second merge registration request sent by the first core network device, wherein the second merge registration request is used to request the establishment of a context for the terminal under the second RAT.

[0016] This application provides a terminal, including a transceiver, a processor, and a memory. The memory stores a computer program, the transceiver communicates with other devices, and the processor calls and runs the computer program stored in the memory to enable the terminal to perform the methods described above.

[0017] This application provides a first core network device, including a transceiver, a processor, and a memory. The memory stores a computer program, the transceiver communicates with other devices, and the processor calls and runs the computer program stored in the memory to cause the first core network device to perform the aforementioned method.

[0018] This application provides a second core network device, including a transceiver, a processor, and a memory. The memory stores a computer program, the transceiver communicates with other devices, and the processor calls and runs the computer program stored in the memory to enable the second core network device to perform the methods described above.

[0019] This application provides a chip for implementing the above method.

[0020] Specifically, the chip includes a processor for retrieving and running a computer program from memory, causing a device equipped with the chip to perform the methods described above.

[0021] This application provides a computer-readable storage medium for storing a computer program, which, when run by a device, causes the device to perform the above-described method.

[0022] This application provides a computer program product, including computer program instructions that cause a computer to perform the above-described method.

[0023] By adopting the above scheme, the terminal requests the core network to establish a context for the terminal under the first RAT and the second RAT through the access network device corresponding to one RAT. In this way, the terminal does not need to register multiple times through access network devices corresponding to multiple RATs. Instead, it only needs to complete the merged registration under multiple RATs with a single registration request, that is, to establish the context of the terminal under multiple RATs in the core network. This reduces the amount of signaling required for the terminal registration process in multi-RAT scenarios, thereby reducing air interface signaling overhead, saving air interface resources, and ultimately improving the terminal's communication efficiency. Attached Figure Description

[0024] Figure 1 is a schematic diagram of an application scenario according to an embodiment of this application.

[0025] Figure 2 is a schematic flowchart of a communication method according to an embodiment of this application.

[0026] Figure 3 is a schematic flowchart of a communication method according to another embodiment of this application.

[0027] Figure 4 is a schematic flowchart of a communication method according to another embodiment of this application.

[0028] Figure 5 is a schematic diagram of a scenario in which multiple access terminals and the core network exist simultaneously according to an embodiment of this application.

[0029] Figures 6 to 10 are various schematic flowcharts of the terminal merging registration process according to an embodiment of this application.

[0030] Figure 11 is a schematic block diagram of a terminal according to an embodiment of this application.

[0031] Figure 12 is a schematic block diagram of a first core network device according to an embodiment of the present application.

[0032] Figure 13 is a schematic block diagram of a second core network device according to an embodiment of the present application.

[0033] Figure 14 is a schematic block diagram of a communication device according to an embodiment of this application.

[0034] Figure 15 is a schematic block diagram of a chip according to an embodiment of this application. Detailed Implementation

[0035] The technical solutions of this application embodiment can be applied to various communication systems, such as: LTE (Long Term Evolution), LTE-A (Long Term Evolution-Advanced), NR (New Radio), evolution of NR, WLAN (Wireless Local Area Network), WiFi (Wireless Fidelity), or other communication systems.

[0036] This application describes various embodiments in conjunction with network devices and terminals. The terminal can be mobile or fixed, and may also be referred to as a mobile station, user unit, etc. The terminal can be a station in a WLAN, or a smart terminal, wireless modem, laptop, tablet, etc. In this application embodiment, the terminal can be a VR (Virtual Reality) terminal / AR (Augmented Reality) terminal, industrial control terminal, autonomous driving terminal, telemedicine terminal, smart grid terminal, transportation safety terminal, smart city terminal, or smart home wireless terminal, etc. By way of example and not limitation, in this application embodiment, the terminal can also be a wearable device.

[0037] In this embodiment, the network device can be a device for communicating with a terminal. The network device can be an access point in a WLAN, an evolved base station in LTE, a relay station, a vehicle-mounted device, a wearable device, a network device in an NR network (gNB, the next generation Node B), a network device in a future PLMN network, or a network device in a non-terrestrial network, etc. By way of example and not limitation, in this embodiment, the network device can have mobility characteristics; for example, the network device can be a mobile device.

[0038] To facilitate understanding of the technical solutions of the embodiments of this application, the relevant technologies of the embodiments of this application are described below. The following relevant technologies are optional solutions and can be combined with the technical solutions of the embodiments of this application in any way, and they all fall within the protection scope of the embodiments of this application.

[0039] Figure 1 exemplarily illustrates a communication system 100. The communication system includes network devices 110 and terminals 120. In one possible implementation, the communication system 100 may include multiple network devices 110, and the coverage area of ​​each network device 110 may include one or more terminals 120; this embodiment does not limit this. In another possible implementation, the communication system 100 may also include other network entities such as mobility management entities and access and mobility management functions; this embodiment does not limit this. The network devices may further include access network devices and core network devices. That is, the communication system may also include multiple core networks for communicating with the access network devices. The access network devices may be base stations of LTE, LTE-A, or NR systems. Taking the communication system shown in Figure 1 as an example, the communication devices may include network devices and terminals with communication functions. The communication devices may also include other devices in the communication system, such as network controllers, mobility management entities, and other network entities; this embodiment does not limit this.

[0040] To facilitate understanding of the embodiments of this application, the basic concepts involved in the embodiments of this application are briefly explained below. It should be understood that the basic concepts introduced below do not limit the embodiments of this application.

[0041] In related technologies, connection management includes the function of establishing and releasing N1 NAS (Non-access stratum) signaling connections (or NAS connections) between a UE (User Equipment) and an AMF (Access and Mobility Management Function). The N1 NAS signaling connection enables signaling interaction between the UE and the core network. This N1 NAS signaling connection may include connections between the UE and access network equipment, and N2 connections between the access network equipment and the AMF for the UE.

[0042] The N1 NAS signaling connection between the UE and the AMF includes the following two states: CM (Connection Management) - IDLE (idle or idle state) and CM - CONNECTED (connected or connected state).

[0043] When the UE is in CM-IDLE, there are no corresponding N1, AN (Access Network) signaling, N2, or N3 connections. If the UE is simultaneously in CM-IDLE and RM (Registration Management)-REGISTERED states, the UE needs to initiate a service request procedure to respond to paging, unless the UE is in MICO (Mobile Initiated Connection Only) mode; or, if the UE is simultaneously in CM-IDLE and RM (Registration Management)-REGISTERED states, it initiates a service request procedure when it has uplink signaling or data to send. Correspondingly, when the UE state on the AMF side is RM-REGISTERED, the information required for network-to-UE communication is stored in the AMF, which can obtain this information through the 5G-GUTI (5G Globally Unique Temporary Identifier). The UE will provide AN parameters such as 5G-S-TMSI during the AN signaling connection establishment process. Additionally, when the UE is in CM-IDLE state, it can enter MICO mode to reduce power consumption and signaling overhead.

[0044] The state transitions between CM-IDLE (idle state) and CM-CONNECTED (connected state) in the N1 NAS signaling connection between the UE and AMF are explained below:

[0045] When the UE is in CM-IDLE state, it should enter CM-CONNECTED state whenever an AN signaling connection is established. Specifically, when the UE is in CM-IDLE state, it sends an initial NAS signaling message (e.g., any one of Registration Request, Service Request, or Deregistration Request) to initiate the transition from CM-IDLE state to CM-CONNECTED state on the UE side.

[0046] When a UE is in CM-CONNECTED state, an N1 NAS signaling connection exists between the UE and the AMF. This N1 NAS signaling connection utilizes the RRC (Radio Resource Control) connection between the UE and the NG-RAN, and the NGAP (Next Generation Application Protocol) UE association between the AN and the AMF. A UE can be in CM-CONNECTED state without the NGAP being bound to any transport network layer. After the NAS signaling process is completed, the AMF can decide to release the NAS signaling connection with the UE. For example, when the UE is in CM-CONNECTED, the UE enters the CM-IDLE state whenever the AN signaling connection is released; and / or the logical NGAP signaling connection and the UE's N3 user plane connection enter the CM-IDLE state after the AN is released.

[0047] When the UE state stored in the AMF is CM-IDLE or RM-REGISTRATION, the AMF needs to initiate a paging process to the UE and receive a response when it needs to send signaling or data to the UE, thus executing the service request procedure initiated by the network side. On the AMF side, whenever an N2 connection is established and / or an N2 context is established for a UE, the UE's state in the AMF will enter the CM-CONNECTED state. That is, the initial reception of an N2 message will initiate the transition of the UE state stored in the AMF from CM-IDLE to CM-CONNECTED. The AMF can maintain the UE connection state in CM-CONNECTED until the UE deregisters from the network, i.e., when the N2 context is released, the UE state stored in the AMF will transition from CM-CONNECTED to CM-IDLE.

[0048] In addition, a UE in CM-CONNECTED state can also be in RRC_INACTIVE state. In this state, the RAN releases the AN connection with the UE, and the UE moves within the area configured by the RAN. The N2 connection remains, and the UE's reachability is managed by the RAN based on auxiliary information provided by the network side. UE paging is managed by the RAN, and the UE listens for paging messages containing its corresponding network identifier (5G S-TMSI) and the RAN identifier. When the UE leaves the area configured by the RAN, it needs to notify the RAN. UE reachability management is responsible for detecting whether the UE is reachable and providing the network with the UE's location (i.e., access node) so that information sent by the network can reach the UE. This process is accomplished through paging the UE and UE location tracking. UE location tracking includes UE registration area tracking (i.e., UE registration area update) and UE reachability tracking (i.e., UE periodic registration area update). This function can be configured in 5GC (in CM-IDLE state) or NG-RAN (in CM-CONNECTED state). The UE and AMF negotiate the UE reachability characteristics in the CM-IDLE state during the registration process.

[0049] Whenever a UE in RM-REGISTERED state enters CM-IDLE state, the UE starts a periodic registration timer based on the periodic registration timer allocated by the AMF during the registration process. The UE needs to perform periodic registration upon the expiration of the periodic registration timer. If the UE moves out of network coverage when its periodic registration timer expires, the UE should perform the registration process upon its next return to coverage.

[0050] The AMF runs a mobile reachability timer for the UE. Whenever a UE in the RM-REGISTERED state changes its CM state to CM-IDLE, the timer starts with a value longer than the UE's periodic registration timer. If the AMF receives an elapsed time from the RAN when the RAN initiates a UE context release indicating the UE is unreachable, the AMF should derive the mobile reachability timer value based on the elapsed time received from the RAN and the normal mobile reachability timer value. If the UE's CM state in the AMF moves to the CM-CONNECTED state, the AMF stops the mobile reachability timer. If the mobile reachability timer expires, the AMF determines the UE is unreachable. When the mobile reachability timer expires, the AMF cannot know whether the UE is only temporarily unreachable, and therefore will not immediately register the UE. The AMF clears the paging processing indicator bit and starts the implicit deregistration timer only after the mobile reachability timer expires. If the UE becomes CM-CONNECTED before the timer expires, the AMF should stop the implicit registration timer and set the PPF. Otherwise, after the implicit registration timer expires, the AMF initiates the UE's privacy deregistration.

[0051] If the UE indicates the duration of the unavailability period, the AMF will consider the UE unreachable and will not trigger a paging procedure until the UE re-registers for normal service. Once the event causing the UE to become unavailable is completed or canceled within the UE, the UE will initiate a registration procedure to restore normal service. If the UE's CM state in the AMF is CM-IDLE, the AMF considers a UE in RM-REGISTERED to be reachable via CN paging, unless the UE applies MICO mode or the UE has indicated the duration of the unavailability period.

[0052] NGAP provides the signaling services required between NG-RAN (Radio Access Network) nodes and AMF. Services on NGAP are divided into two types: non-UE-associated services, which are associated with the entire NG interface instance between NG-RAN nodes and AMF, using non-UE-associated signaling connections; and UE-associated services, where the NGAP function providing the service is associated with a UE-associated signaling connection maintained for a specific UE.

[0053] For UE-associated services via NGAP, after the NG-RAN receives the first uplink NAS (Non-Access Stratum) message via the radio interface, the NG-RAN will initiate an initial UE message procedure. The NG-RAN node should assign a unique RAN UE NGAP ID for the UE, and this identifier should be included in the initial UE message. If the initial UE message contains a UE Context Request information element, the AMF should trigger an Initial Context Setup procedure to the NG-RAN node.

[0054] If a logical NG connection associated with the UE exists, or the AMF receives the RAN UE NGAP ID information element in the INITIAL UE MESSAGE message, or the NG-RAN node has initiated a logical NG connection associated with the UE by sending an INITIAL UE MESSAGE message through another NG interface instance, the AMF may initiate the initial context establishment procedure. The purpose of this initial context establishment procedure is to establish the necessary overall initial UE context at the NG-RAN node when needed. This overall UE context may include the PDU session context, security key, mobility restriction list, UE radio capabilities, and UE security capabilities, etc.

[0055] The downlink NAS transmission procedure on the AMF side is used when the AMF only needs to transparently send NAS messages to the UE through the NG-RAN node. The AMF can trigger the downlink NAS transmission procedure when one of the following conditions is met: a logical NG connection associated with the UE exists; the AMF receives the RAN UE NGAP ID information element in the INITIAL UE MESSAGE message; or the NG-RAN node has already initiated the logical NG connection associated with the UE by sending an INITIAL UE MESSAGE message through another NG interface instance. During the downlink NAS transmission procedure, if the logical NG connection associated with the UE has not yet been established, the AMF will assign a unique AMF UE NGAP ID to the UE and send it to the NG-RAN in a DOWNLINK NAS TRANSPORT message; correspondingly, the NG-RAN establishes the logical NG connection associated with the UE by receiving the AMF UE NGAP ID information element in the downlink NAS transmission message.

[0056] Figure 2 is a schematic flowchart of a communication method according to an embodiment of this application. The method includes at least a portion of the following.

[0057] S210. The terminal sends a first merged registration request to the first core network device through the access network device corresponding to the first RAT, wherein the first merged registration request is used to request the core network to establish a context for the terminal under the first RAT and the second RAT.

[0058] Figure 3 is a schematic flowchart of a communication method according to an embodiment of this application. The method includes at least a portion of the following.

[0059] S310. The first core network device receives a first merged registration request sent by the terminal through the access network device corresponding to the first RAT, wherein the first merged registration request is used to request the establishment of a context for the terminal in the core network under the first RAT and the second RAT.

[0060] Figure 4 is a schematic flowchart of a communication method according to an embodiment of this application. The method includes at least a portion of the following.

[0061] S410, the second core network device receives a second merge registration request from the first core network device, wherein the second merge registration request is used to request the establishment of a context for the terminal under the second RAT.

[0062] In this embodiment of the application, the terminal may or may not support multiple access capabilities.

[0063] If a terminal supports multiple access capabilities, then the terminal can be a terminal with multiple access capabilities. This terminal with multiple access capabilities can be called a multi-access device, a dual-access device, or a multi-access UE, etc. A terminal with multiple access capabilities can have multiple communication protocol stacks and can be a single-SIM terminal or a multi-SIM terminal; a single-SIM terminal refers to a terminal with a single USIM (Universal Subscriber Identity Module) card, while a multi-SIM terminal refers to a terminal with multiple USIM cards. For example, a Mobile Station (MS), i.e., a terminal, can be configured with USIM-1 and USIM-2, and can connect to access network devices in two access networks, AN (Access Network)-1 and AN-2, through the UU interface (air interface) to access the core network (such as the core network of a PLMN (Public Land Mobile Network)) through AN-1 and AN-2 respectively.

[0064] Multi-access capability can include the ability to access the core network through multiple RATs. Multi-access can also be referred to as dual access, dual radio, or multiple connections, etc. Specifically, the ability to access the core network through multiple RATs can mean the ability to access the core network through the access network device corresponding to each of the multiple RATs. For a terminal with multi-access capability, the terminal can connect to the core network through multiple access network devices of multiple RATs. Connections corresponding to the terminal can exist separately between the control plane network elements on the core network side and different access network devices among the multiple access network devices. Furthermore, the signaling transmission of the terminal on the multiple access network devices is independent of each other. The connection between any access network device corresponding to the terminal and the control plane network element can be an NGAP (Next Generation Application Protocol) connection.

[0065] Multiple access or multiple connections refer to a single terminal having multiple connections to one or more core networks. Each connection connects to the core network through different access network devices (or access network devices corresponding to different RATs) and registers with the same or different networks (or the core network or control plane network elements on the core network side). The connection primarily refers to the NAS connection between the terminal and the core network.

[0066] Furthermore, multiple access terminals can simultaneously communicate with the core network via multiple access lines. On each line, the terminal can connect to the core network through different access network devices (or access network devices corresponding to different RATs). That is, the RRC connection, NGAP connection, and NAS connection between the terminal and the core network on each line are unique to that line and different from the others. For example, a terminal can establish an RRC connection with an access network device on one line for transmitting signaling or messages; this access network device can establish an NGAP connection with the core network corresponding to that terminal for transmitting signaling or messages. In addition, the terminal can establish different sessions (or user plane resources) on different lines to receive or send service data. In other words, the terminal can simultaneously establish multiple sessions through multiple access network devices (or access network devices corresponding to multiple RATs). For example, a terminal can establish a DRB (Data Radio Bearer) with an access network device on one line to carry service data or session data; this access network device can establish a GTU (GPRS Tunneling Protocol for the User) with the core network. The Plane (GPRS and 5G User Plane Tunneling Protocol) tunnel is used to transmit or carry the data of the service or session.

[0067] Referring to Figure 5, the UE has a first leg connecting to the core network via AN-1. On this first leg, there is an RRC connection-1 between the UE and AN-1, an NGAP-1 (or NGAP connection-1) between the UE and AN-1, a DRB-1 between the UE and AN-1 for carrying service data for session-1, and a GTU tunnel-1 between AN-1 and the core network for transmitting service data for session-1. The UE has a second leg connecting to the core network via AN-2. On this second leg, there is an RRC connection-2 between the UE and AN-2, an NGAP-2 (or NGAP connection-2) between the UE and AN-2, a DRB-2 between the UE and AN-2 for carrying service data for session-2, and a GTU tunnel-2 between AN-2 and the core network for transmitting service data for session-2.

[0068] The type of RAT (Radio Access Technology) can be any of the following: E-UTRA (Evolved Universal Terrestrial Radio Access), NR terrestrial access, NR satellite access, 6G access, etc. NR terrestrial access can also be referred to as the transmission technology corresponding to the TN (Terrestrial Network) access network; NR satellite access can also be referred to as the transmission technology corresponding to the NTN access network. NR satellite access can include at least one of NR(LEO), NR(GEO), NR(LEO), etc.

[0069] The first RAT and the second RAT are RATs under different communication systems. That is, the first RAT can be a RAT under a first communication system, and the second RAT can be a RAT under a second communication system. The first and second communication systems are different. The first RAT corresponds to the first communication system or the core network of the first communication system, and the second RAT corresponds to the second communication system or the core network of the second communication system. For example, the first communication system can be a 5G system (5GS), and the first RAT can be a RAT under 5GS (such as NR terrestrial access or NR satellite access). The second communication system can be a 6G system (6GS), and the second RAT can be a RAT under 6GS, or vice versa.

[0070] The first core network equipment is the control plane network element on the core network side of the first communication system; the second core network equipment is the control plane network element on the core network side of the second communication system. The control plane network element can be any one of the following: MM (Mobility Management) network element, AMF (Access and Mobility Management Function), etc.

[0071] The first merged registration request carries at least one of the following: the identifier of the terminal, the identifier of the access network device corresponding to the second RAT, the identifier of the cell corresponding to the access network device corresponding to the second RAT, the area information corresponding to the access network device corresponding to the second RAT, the type information of the second RAT, the location information of the terminal, and first indication information, wherein the first indication information is used to indicate that the terminal is registered and managed in multiple RATs.

[0072] The following describes the process of terminal merging registration in conjunction with various embodiments.

[0073] In some possible implementations, the control plane network elements (or mobility management network elements) of the core networks of the first and second communication systems are co-located. That is, the equipment of the first core network is the same as that of the second core network. For example, if the first and second communication systems are 5GS and 6GS respectively, the control plane network elements of the 5GS and 6GS systems are both equipment of the first core network.

[0074] In this case, establishing a context for the terminal in the core network under the first RAT and the second RAT can refer to the first core network device establishing a context for the terminal under the first RAT and the second RAT. In the embodiments of this application, the context established for the terminal in the core network can refer to the terminal context (or UE context), which will not be repeated below.

[0075] The first merged registration request is used to request the first core network device to establish a context for the terminal under the first RAT and the second RAT.

[0076] Furthermore, the first merged registration request can be used to request the first core network device to perform registration management for the terminal in multiple RATs, or to request the first core network device to perform registration management for the terminal in multiple legs.

[0077] It should be noted that the first merged registration request can be used not only to request the first core network device to establish a context for the terminal under the first RAT and the second RAT, but also to request the first core network device to establish a context for the terminal under more other RATs. For example, the first merged registration request can be used to request the first core network device to establish a context for the terminal under the first RAT, the second RAT, and the third RAT. The relevant processing for the third RAT or more other RATs is the same as that for the second RAT. Therefore, the following mainly describes the second RAT and the first RAT, and will not describe the relevant processing for more other RATs. The following will not repeat the explanation.

[0078] In some embodiments, the first merged registration request may carry at least one of the following: the identifier of the terminal, the identifier of the access network device corresponding to the second RAT, the identifier of the cell corresponding to the access network device corresponding to the second RAT, and first indication information.

[0079] The identifier of the terminal may include at least one of the following: the terminal's AS (Access Stratum) identifier, or the terminal's NAS identifier.

[0080] The NAS identifier of a terminal may include at least one of the following: the terminal's SUPI (Subscription Permanent Identifier), the terminal's SUCI (Subscription Concealed Identifier), or the terminal's GUTI (Globally Unique Temporary Identifier). The terminal's GUTI may be the GUTI currently stored by the terminal, such as the GUTI assigned to the terminal by the network side (e.g., the core network) when the terminal last accessed the network.

[0081] The AS identifier of a terminal may include 5G-S-TMSI (Temporary Mobile Subscription Identifier), etc.

[0082] The first indication information may include at least one of the following: registration type, the capabilities of the terminal.

[0083] Optionally, the first indication information may include a registration type, which is a combined registration. By including the combined registration type in the first indication information, the terminal may be instructed to request registration management for itself in multiple RATs.

[0084] Optionally, the first indication information may include the capabilities of the terminal. The capability information of the terminal may include the multi-access capability that the terminal possesses, or the terminal supports multiple accesses. By including the multi-access capability that the terminal possesses, or the terminal supports multiple accesses in the first indication information, the terminal may be instructed to request registration management for itself in multiple RATs.

[0085] The identifier of the access network device can be the Global RAN node ID. The identifier of the access network device corresponding to the second RAT can be pre-configured on the terminal side; or, the identifier of the access network device corresponding to the second RAT is the identifier of the access network device under which the terminal establishes an RRC connection; or, the terminal can obtain the identifier of the access network device corresponding to the second RAT from the broadcast message of the access network device corresponding to the second RAT.

[0086] If the terminal has established an RRC connection with the access network device corresponding to multiple RATs, and the multiple RATs include at least the first RAT and the second RAT, then the terminal has obtained the identifier of the access network device corresponding to the second RAT.

[0087] The process of obtaining the identifier of the access network device corresponding to the second RAT from the broadcast message of the access network device corresponding to the second RAT mainly occurs when the terminal is about to establish an RRC connection with the access network device corresponding to the second RAT and the terminal is within the coverage area of ​​the access network device corresponding to the second RAT. The terminal can obtain the identifier of the access network device corresponding to the second RAT from the broadcast message of the access network device corresponding to the second RAT. The identifier of the access network device corresponding to the second RAT can be carried in the SIB (System Information Block) of this broadcast message.

[0088] The identifier of the cell corresponding to the access network device can be a cell ID or a PCI (Physical Cell Identity). The identifier of the cell corresponding to the access network device of the second RAT can be obtained by the terminal from the broadcast message of the access network device corresponding to the second RAT.

[0089] The processing after the first core network device receives the first merged registration request may further include: the first core network device determining whether merged registration is supported based on at least one of local configuration, terminal subscription data, and network capabilities. The terminal's subscription information can be obtained from the UDM; the local configuration may include whether the first core network device itself can provide relevant configurations for merged registration, and this local configuration may also be operator configuration; the network capabilities may include the capabilities of the network where the first core network device is located (e.g., the core network side), which may include whether the network supports merged registration, etc. The network capabilities are not limited or exhaustively listed here. This embodiment does not limit the specific processing method by which the first core network device determines whether merged registration is supported based on at least one of local configuration, terminal subscription data, and network capabilities.

[0090] After determining that merged registration is supported, and before sending a first merged registration acceptance message to the terminal through the access network device corresponding to the first RAT, the first core network device may also establish a second connection with the access network device corresponding to the second RAT. Specifically, before sending the first merged registration acceptance message to the terminal through the access network device corresponding to the first RAT, the process further includes: the first core network device sending a connection establishment request to the access network device corresponding to the second RAT, wherein the connection establishment request is used by the access network device corresponding to the second RAT to establish a second connection; and the first core network device receiving a connection establishment response sent by the access network device corresponding to the second RAT, wherein the connection establishment response is used to indicate the completion of establishing the second connection.

[0091] Preferably, the first merged registration request may carry at least the identifier of the access network device corresponding to the second RAT; correspondingly, the first core network device may directly determine the access network device corresponding to the second RAT based on the identifier of the access network device corresponding to the second RAT. In this case, the first merged registration request may also carry at least one of the terminal identifier and the first indication information.

[0092] Optionally, the first merged registration request may at least carry the identifier of the cell corresponding to the access network device corresponding to the second RAT; correspondingly, the first core network device may locate and determine the access network device corresponding to the second RAT based on the identifier of the cell corresponding to the access network device corresponding to the second RAT. In this case, the first merged registration request may also carry at least one of the terminal identifier and the first indication information.

[0093] The second connection can be used to transmit NAS signaling corresponding to the terminal between the access network device corresponding to the second RAT and the first core network device. For example, the second connection can be referred to as the logical connection associated with the terminal, or the logical connection corresponding to the second RAT associated with the terminal. The logical connection can also be alternatively referred to as a logical NG connection, or an NG connection, etc.

[0094] Before sending a connection establishment request to the access network device corresponding to the second RAT, the first core network device can also assign a unique core network identifier to the second connection. This identifier assigned by the first core network device can be called the core network identifier corresponding to the second connection, or the identifier of the first core network device corresponding to the second connection. For example, if the first core network device is an MM (Multi-Node), the core network identifier corresponding to the second connection can be represented as the MM UE NGAP ID; if the first core network device is an AMF (Multi-Node), the core network identifier corresponding to the second connection can be represented as the AMF UE NGAP ID.

[0095] The connection establishment request can be an N2 message between the first core network device and the access network device corresponding to the second RAT. The N2 message can be any one of the following: downlink NAS transport, initial context setup, or connection establishment indication.

[0096] The connection establishment request may carry at least one of the following: the identifier of the terminal, or the identifier of the core network side corresponding to the second connection.

[0097] After receiving the connection establishment request, the access network device corresponding to the second RAT can also assign a unique identifier to the second connection. This unique identifier assigned by the access network device corresponding to the second RAT is called the identifier of the access network device corresponding to the second RAT of the second connection. For example, the identifier of the access network device corresponding to the second RAT of the second connection can be represented as RAN UE NGAP ID or RAN-2UE NGAP ID.

[0098] The connection establishment response may carry at least one of the following: the identifier of the terminal, the identifier of the access network device corresponding to the second RAT corresponding to the second connection, and the identifier of the core network corresponding to the second connection.

[0099] After the first core network device receives the first merge registration request from the terminal via the access network device corresponding to the first RAT (or after receiving the connection establishment response from the access network device corresponding to the second RAT), the process further includes: the first core network device sending a first merge registration acceptance message to the terminal via the access network device corresponding to the first RAT, wherein the first merge registration acceptance message is used by the terminal to determine that the core network has completed the merge registration of the first RAT and the second RAT. Correspondingly, after the terminal sends the first merge registration request to the first core network device via the access network device corresponding to the first RAT, the process further includes: the terminal receiving the first merge registration acceptance message from the first core network device via the access network device corresponding to the first RAT.

[0100] Specifically, the first merge registration acceptance message is used by the terminal to determine that the first core network device has completed the merge registration of the first RAT and the second RAT.

[0101] The first merged registration acceptance message carries at least one of the following: the identifier of the terminal, the identifier of the second connection, second indication information, one or more registration areas, and one or more NAS identifiers for paging, wherein the second indication information is used to indicate the completion of the establishment of the first connection and the second connection, the first connection is used for transmitting NAS signaling corresponding to the terminal between the access network device corresponding to the first RAT and the core network, and the second connection is used for transmitting NAS signaling corresponding to the terminal between the access network device corresponding to the second RAT and the core network.

[0102] The identifier of the second connection includes at least one of the following: the identifier of the access network device corresponding to the second RAT of the second connection, and the identifier of the core network device corresponding to the second connection.

[0103] It should be noted that if the terminal's identifier is carried in the connection establishment request sent by the first core network device to the access network device corresponding to the second RAT, the identifier of the second connection may not be carried in the first merged registration acceptance message. This is because the access network device corresponding to the second RAT can bind and associate the terminal's identifier with the identifier of the second connection. Therefore, if the terminal subsequently transmits messages (such as NAS messages or NAS signaling) with the first core network device through the access network device corresponding to the second RAT, by carrying the terminal's identifier in the access layer message carrying the message, the access network device corresponding to the second RAT can identify the terminal and determine the second connection corresponding to the terminal, and thus be able to send the terminal's messages to the first core network device through the second connection.

[0104] If the connection establishment request sent by the first core network device to the access network device corresponding to the second RAT does not carry the terminal's identifier, the first merged registration acceptance message can carry the identifier of the second connection. If the terminal subsequently transmits messages (such as NAS messages or NAS signaling) with the first core network device through the access network device corresponding to the second RAT, by carrying the identifier of the second connection in the access layer message carrying the message, the access network device corresponding to the second RAT can determine the second connection corresponding to the terminal, and thus be able to send the terminal's messages to the first core network device through the second connection.

[0105] In this embodiment, the core network specifically refers to a first core network device. That is, the first connection is used for transmitting NAS signaling corresponding to the terminal between the access network device corresponding to the first RAT and the first core network device, and the second connection is used for transmitting NAS signaling corresponding to the terminal between the access network device corresponding to the second RAT and the first core network device. The process of establishing the first connection between the first core network device and the access network device corresponding to the first RAT is similar to the aforementioned process of establishing the second connection between the first core network device and the access network device corresponding to the second RAT, and will not be described in detail here.

[0106] In addition to indicating the completion of the establishment of the first connection and the second connection, the second indication information can also be used to indicate that the network side supports merged registration, which may include the first core network device.

[0107] The one or more Registration Areas (RAs) include at least one of the following: the registration area corresponding to the first RAT, the registration area corresponding to the second RAT, and the registration areas corresponding to both the first RAT and the second RAT.

[0108] In this embodiment, since the first core network device is shared by the first communication system and the second communication system, the registration area allocated to the first core network device may include: the registration area corresponding to the first RAT and the registration area corresponding to the second RAT; or, the registration area allocated to the first core network device may include: the registration areas corresponding to the first RAT and the second RAT.

[0109] The one or more NAS identifiers for paging include at least one of the following: a NAS identifier for paging corresponding to a first RAT, a NAS identifier for paging corresponding to a second RAT, or a NAS identifier for paging corresponding to both the first RAT and the second RAT. The type of the NAS identifier for paging can be GUTI or TMSI, wherein TMSI can be obtained by truncating GUTI; the specific truncating method is not limited in this embodiment.

[0110] Since the first core network device is shared by the first communication system and the second communication system, one or more NAS identifiers allocated by the first core network device for paging may include: the NAS identifier for paging corresponding to the first RAT and the NAS identifier for paging corresponding to the second RAT; or, one or more NAS identifiers allocated by the first core network device for paging may include: the NAS identifiers for paging corresponding to the first RAT and the second RAT.

[0111] After the terminal receives the first merged registration acceptance message from the first core network device through the access network device corresponding to the first RAT, the method further includes at least one of the following: the terminal transmits the NAS signaling corresponding to the terminal through the access network device corresponding to the first RAT, wherein the access network device corresponding to the first RAT transmits the NAS signaling corresponding to the terminal through the first connection; the terminal transmits the NAS signaling corresponding to the terminal through the access network device corresponding to the second RAT, wherein the access network device corresponding to the second RAT transmits the NAS signaling corresponding to the terminal through the second connection.

[0112] For example, after receiving the first merged registration acceptance message, the terminal can establish an RRC connection with the access network device corresponding to the second RAT according to actual needs. Then, the terminal transmits the uplink NAS signaling corresponding to the terminal to the access network device corresponding to the second RAT through the RRC connection of the access network device corresponding to the second RAT. Then, the access network device corresponding to the second RAT sends the uplink NAS signaling corresponding to the terminal to the first core network device through the second connection; and / or, the first core network device sends the downlink NAS signaling corresponding to the terminal to the access network device corresponding to the second RAT through the second connection. The access network device corresponding to the second RAT sends the downlink NAS signaling corresponding to the terminal to the terminal through the RRC connection between the terminal and the terminal.

[0113] Furthermore, the terminal can also establish user plane resources or data plane resources with the core network side through the access network equipment corresponding to the second RAT, and transmit uplink data and / or downlink data of the session through the user plane resources or data plane resources.

[0114] For example, after receiving the first merged registration acceptance message, the terminal can, according to actual needs, transmit the uplink NAS signaling corresponding to the terminal to the access network device corresponding to the first RAT through the RRC connection of the access network device corresponding to the first RAT. Then, the access network device corresponding to the first RAT sends the uplink NAS signaling corresponding to the terminal to the first core network device through the first connection; and / or, the first core network device sends the downlink NAS signaling corresponding to the terminal to the access network device corresponding to the first RAT through the first connection. The access network device corresponding to the first RAT sends the downlink NAS signaling corresponding to the terminal to the terminal through the RRC connection between the terminal and the terminal.

[0115] Furthermore, the terminal can also establish user plane resources or data plane resources with the core network side through the access network equipment corresponding to the first RAT, and transmit uplink data and / or downlink data of the session through the user plane resources or data plane resources.

[0116] Optionally, during the process of establishing a second connection with the access network device corresponding to the second RAT, or after the establishment of the second connection, the first core network device may also establish an N2 context under the second RAT for the terminal, and establish an overall initial UE context for the terminal on the access network device side corresponding to the second RAT through an initial context procedure. The content included in this overall initial UE context may be the same as that of the relevant protocol, for example, it may include at least one of the following: PDU session context, security key, mobility restriction list, UE radio capabilities, and UE security capabilities, etc., wherein the security key is the key key material of the NG-RAN node or the next hop, and the security key can be used to derive security keys (such as access layer security keys) for user layer traffic and RRC signaling information.

[0117] Optionally, if the first core network device determines that it does not support merged registration, or if the first core network device fails to establish a second connection with the access network device corresponding to the second RAT, the method may further include: the first core network device sending a first merged registration rejection message to the terminal through the access network device corresponding to the first RAT. This first merged registration rejection message may carry at least one of the following: the terminal's identifier, a rejection reason, etc. The rejection reason may include the first core network device not supporting merged registration and / or the first core network device failing to establish a second connection with the access network device corresponding to the second RAT.

[0118] Optionally, if the first core network device determines that it does not support merged registration, or if the first core network device fails to establish a second connection with the access network device corresponding to the second RAT, the first core network device may accept partial registration. That is, the first core network device may accept registration from the access network device corresponding to the first RAT (i.e., only establishing a terminal context under the first RAT on the first core network device side). The processing of the first core network device may further include: the first core network device sending a partial registration acceptance message to the terminal through the access network device corresponding to the first RAT. This partial registration acceptance message may carry at least one of the following: the terminal's identifier, seventh indication information, the registration area corresponding to the first RAT, and the NAS identifier for paging corresponding to the first RAT. The seventh indication information may be used to indicate acceptance of registration under the first RAT, or that registration on the access network device corresponding to the first RAT has been successfully accepted.

[0119] After receiving a partial registration acceptance message from the first core network device through the access network device corresponding to the first RAT, the terminal can also resend a new registration request to the first core network device through the access network device corresponding to the second RAT to complete the registration under the second RAT. The specific processing is not limited here.

[0120] Referring to Figure 6, taking the example of two communication systems sharing a single mobility management network element in their core networks, the process of terminal merging registration is illustrated as follows:

[0121] Step 601: The UE (which can be a multi-access terminal) can send a merge registration request (i.e., a first merge registration request) to the MM (i.e., the first core network device) through AN-1 (i.e., the access network device corresponding to the first RAT), requesting registration management for its multiple access points or multiple legs, that is, establishing contexts for the UE under multiple RATs (including the first RAT and the second RAT) on the core network side. The merge registration request includes at least one of the following parameters:

[0122] The UE identification information (or simply UE identifier), such as SUPI, SUCI, GUTI, etc., may also include AS identifier information, such as 5G-S-TMSI, in addition to the NAS identifier. The AS identifier information is used by AN-2 (the access network device corresponding to the second RAT) to associate the UE association logical NG connection established for the UE with the UE, so that AN-2 can forward signaling messages to MM for the UE through the NG connection.

[0123] The first instruction message instructs the UE to register for multiple access networks through this registration request. Alternatively, it instructs the UE to support merged registration.

[0124] The identification information of the access network device AN-2 (or simply AN-2 identifier) ​​is the identifier of other access network devices that the UE requests to register together through this registration request, such as the global RAN node ID or cell ID.

[0125] The access network device AN-2 identifier can be obtained in the following ways: a pre-configured access network device AN-2 identifier; the access network device AN-2 currently connected to multiple access terminals, i.e., the access network device AN-2 that has already established an RRC connection with multiple access terminals; the access network device AN-2 that the multiple access terminals will access, i.e., the multiple access devices AN-2 with which the UE will establish an RRC connection, at which time the multiple access terminals are within the coverage area of ​​the access network device AN-2, and the multiple access terminals can obtain information such as cell ID and global RAN node ID from the broadcast message (e.g., SIB) of the access network device AN-2.

[0126] Step 602: Based on at least one of the following—local configuration, UE subscription data, and network capabilities—it is determined whether merged registration is supported. If supported, the MM will send a request message (i.e., connection establishment request) to the access network device AN-2 to establish a logical NG connection associated with the UE. This request message can be any N2 message such as Downlink NAS transport, Initial Context Setup, or Connection Establishment Indication. In other words, the MM requests to establish a logical NG connection (i.e., a second connection) associated with the UE based on the identification information of the access network device AN-2 in the merged registration request message. The MM assigns a unique identifier to the NG connection associated with the UE, such as MM UE NGAP ID or AMF UE NGAP ID.

[0127] The request message (i.e., the connection establishment request) contains at least one of the following:

[0128] The UE's identification information can be AS layer identifiers, such as C-RNTI (Cell Radio Network Temporary Identifier), 5G-S-TMSI (5G-S-Temporary Mobile Subscription Identifier), P-RNTI (Physical Layer Cell Group Identifier), I-RNTI (Initial Radio Network Temporary Identifier), and RNTI (Radio Network Temporary Identifier). Or NAS layer identifiers, such as SUCI (Subscription Concealed Identifier), SUPI (Subscription Permanent Identifier), and 5G-GUTI (5G Globally Unique Temporary Identifier).

[0129] The identifier assigned by MM to the logical NG connection associated with the UE (i.e., the identifier on the core network side corresponding to the second connection), such as MM UE NGAP ID or AMF UE NGAP ID.

[0130] Step 603: After receiving the logical NG connection establishment request associated with the UE, the access network device AN-2 assigns a unique identifier, namely RAN UE NGAP ID, to the logical NG connection associated with the UE, and sends a response message to MM. The response message (i.e., connection establishment response) contains at least one of the following information: UE identification information; the identifier assigned by MM to the logical NG connection associated with the UE, such as MM UE NGAP ID or AMF UE NGAP ID; the unique identifier assigned by the access network device to the logical NG connection associated with the UE (i.e., the identifier on the access network device side corresponding to the second RAT of the second connection), namely RAN UE NGAP ID.

[0131] During or after the establishment of a logical NG connection between the MM and the access network device AN-2 to associate the UE, the MM establishes an N2 context corresponding to the access network device AN-2 for the UE, and establishes the necessary overall initial UE context for the UE at the NG-RAN node through the Initial Context Setup procedure, including PDU session context, security key, mobility restriction list, UE radio capabilities and UE security capabilities, etc.

[0132] Step 604, the MM sends a merge registration acceptance message (i.e., the first merge registration acceptance message) to the UE, the merge registration acceptance message containing at least one of the following information:

[0133] UE identifier;

[0134] The second indication information is used to indicate that the network supports merged registration, or to indicate that the network side has established a logical NG connection, such as NGAP, for the UE between the access network device AN-2 and MM;

[0135] This information is used to indicate to the network side that a logical NG connection associated with the UE has been established between the access network device AN-2 and the MM. Examples include AMF UE NGAP ID and RAN UE NGAP ID. When the UE subsequently sends NAS signaling to the MM via the NG connection, it needs to include this NG connection identification information in the AN message carrying the NAS signaling. If the MM provides UE identification information to the access network device AN-2 in step 602, it is not necessary to provide the identification information of the logical NG connection associated with this UE. In this case, when the UE subsequently sends NAS signaling to the MM via the NG connection, it needs to include the UE identification information in the AN message carrying the NAS signaling.

[0136] The registration area can be the RA used by the UE under all access technologies (or the RA shared by all legs) or the RA used by the UE under each access technology (or the RA used by each leg). Here, the RA used by the UE under all access technologies can be the RA corresponding to the first RAT and the second RAT, and the RA used by the UE under each access technology can include the RA corresponding to the first RAT and the RA corresponding to the second RAT.

[0137] The UE identifier used for paging, such as GUTI, can be a GUTI used by the UE under all access conditions (or a GUTI shared by all legs) or a GUTI used by the UE under each access technology (or a GUTI used by each leg). Here, the GUTI used by the UE under all access conditions can be the GUTI corresponding to the first RAT and the second RAT, and the GUTI used by the UE under each access technology can include the GUTI corresponding to the first RAT and the GUTI corresponding to the second RAT.

[0138] After receiving the merged registration acceptance message, the UE can establish an RRC connection with AN-2 for uplink signaling transmission, or establish data plane resources such as DRB for data transmission and reception. After receiving the partial registration acceptance message, the UE can re-forward the registration request to the access network device AN-2 to the mobility management network element, or in other words, the registration request to the leg corresponding to the access network device AN-2, through the access network device AN-2.

[0139] Additionally, in step 602 above, if the MM does not support merged registration, or if the logical NG connection associated with the UE between the MM and the access network device AN-2 fails to be established, the MM may send a merged registration rejection message to the UE. This merged registration rejection message includes the following information: UE identifier; reason for merged registration failure: for example, the network does not support merged registration for the UE, or the logical NG connection associated with the UE between the MM and the access network device AN-2 fails to be established.

[0140] Additionally, if the MM does not support merged registration, the MM can partially accept merged registration (e.g., the MM only accepts the UE's registration on the access network device AN-1 that forwarded the registration request). The MM can send a partial registration acceptance message to the UE. The partial registration acceptance message includes the following information: UE identifier; seventh indication information, indicating that the UE's registration on the access network device AN-1 (the access network device that forwarded the merged registration request message) is successfully accepted; the registration area assigned to the UE on the access network device AN-1; and the paging identification information (GUTI) assigned to the UE on the access network device AN-1.

[0141] This embodiment provides a second connection between the first core network device and the access network device corresponding to the second RAT, triggered by the first core network device. This allows the first core network device to actively establish the connection for transmitting terminal-related information between the first core network device and the access network device without establishing an RRC connection, thereby enabling the terminal to register in a merged manner on access network devices under multiple RATs. Merged registration allows multiple access terminals to complete registration with multiple access networks through NAS messages forwarded by a single access network device. This reduces the amount of signaling required for the initial terminal registration process, eliminating the need for multiple registrations through different access network devices, reducing air interface signaling overhead, and saving air interface resources.

[0142] In one embodiment, before the terminal sends a first merged registration request to the first core network device through the access network device corresponding to the first RAT, the method further includes: the terminal establishing an RRC connection with the access network device corresponding to the first RAT, and the terminal establishing an RRC connection with the access network device corresponding to the second RAT.

[0143] In this embodiment, the transmission of the first merged registration request and the related description of the content carried by the first merged registration request are the same as in the previous embodiments, and will not be repeated.

[0144] After the first core network device receives the first merged registration request, the terminal and the network side can perform two-way authentication. The network side participating in the two-way authentication of the terminal may include at least one of the first core network device, UDM (Unified Data Management), AUSF (Authentication Server Function), etc. This embodiment does not limit the network elements of the network side participating in the two-way authentication of the terminal, nor the processing of the two-way authentication between the terminal and the network side.

[0145] After the first core network device completes two-way authentication, the first core network device can also establish a second connection with the access network device corresponding to the second RAT. The detailed process of establishing the second connection is the same as in the aforementioned embodiments and will not be repeated here.

[0146] After the first core network device completes the establishment of the second connection, it can activate NAS security for the terminal through the NAS SMC procedure. Specifically, before the first core network device sends the first merged registration acceptance message to the terminal through the access network device corresponding to the first RAT, it further includes: the first core network device sending a first NAS security mode command (SMC) to the terminal through the access network device corresponding to the first RAT. The first NAS security mode command is used to activate a first NAS security context, which is used to protect NAS signaling transmitted by the terminal through the access network device corresponding to the first RAT, or the first NAS security context is used to protect NAS signaling transmitted by the terminal through both the access network device corresponding to the first RAT and the access network device corresponding to the second RAT. Before the terminal receives the first merged registration acceptance message from the first core network device through the access network device corresponding to the first RAT, it further includes: the terminal receiving the first NAS security mode command from the first core network device through the access network device corresponding to the first RAT.

[0147] The first NAS security context may include at least one of the following shared by the terminal and the first core network device: NAS encryption key, NAS integrity protection (hereinafter referred to as integrity protection) key, NAS encryption algorithm, and NAS integrity protection algorithm.

[0148] In this embodiment, since the two communication systems share a first core network device, this first core network device serves as the first NAS security context sent by the terminal. This context can be used to protect the NAS signaling transmitted by the terminal through the access network device corresponding to the first RAT and the access network device corresponding to the second RAT. This protection includes encryption protection and / or integrity protection. In other words, the NAS signaling transmitted between the terminal and the first core network device using the same NAS encryption key and the same NAS encryption algorithm, and / or the same NAS integrity protection key and the same NAS integrity protection algorithm, is protected.

[0149] After receiving the first NAS security mode command, the terminal can also send the first NAS security mode completion message to the first core network device through the access network device corresponding to the first RAT. Here, the messages and their contents that may be transmitted in the NAS SMC process will not be limited or exhaustively listed.

[0150] After the terminal and the first core network device complete the NAS SMC process, the first core network device can send the first merge registration acceptance message to the terminal through the access network device corresponding to the first RAT.

[0151] In one scenario, the description of the first merged registration acceptance message is the same as in the aforementioned embodiments and will not be repeated. In an alternative scenario, the first core network device may send a portion of the first merged registration acceptance message to the terminal via the access network device corresponding to the first RAT, and the first core network device may send another portion of the first merged registration acceptance message to the terminal via the access network device corresponding to the second RAT. For example, the portion of the message sent via the access network device corresponding to the first RAT may include the terminal's identifier, second indication information, the registration area corresponding to the first RAT, and the NAS identifier for paging corresponding to the first RAT; the other portion of the message sent via the access network device corresponding to the second RAT may include the registration area corresponding to the second RAT and the NAS identifier for paging corresponding to the second RAT. It should be noted that this is merely an illustrative example; in actual processing, other methods may be used to send the first merged registration acceptance message to the terminal, which are not limited or exhaustively listed here.

[0152] Optionally, after the first core network device sends a first merged registration acceptance message to the terminal through the access network device corresponding to the first RAT, the method further includes: the first core network device sending a registration message to the UDM, wherein the registration message carries at least one of the following: the identifier of the terminal, the identification information of the first core network device, a fifth indication information, the type information of the first RAT, and information indicating that the associated RAT type is the second RAT, wherein the fifth indication information is used to indicate that the registration type of the terminal is merged registration. That is, if the first core network device accepts merged registration, it can also register with the UDM, and record in the UE context on the UDM that the first core network device is a mobility management network element serving the terminal under the first communication system (or the first RAT of the first communication system) and the second notification system (or the second RAT of the second communication system). The content recorded by the first core network device in the UE context of the UDM may include at least one of the following: the identification information of the first core network device, the type information of the first RAT, and the type information of the second RAT. The identification information of the first core network device may include at least one of the following: the ID of the first core network device, the name of the first core network device, the IP (Internet Protocol) address of the first core network device, the MAC (Media Access Control) address of the first core network device, the FQDN (Fully Qualified Domain Name) of the first core network device, etc.

[0153] After the terminal receives the first merged registration acceptance message from the first core network device through the access network device corresponding to the first RAT, it further includes at least one of the following: the terminal negotiates access layer security parameters between the terminal and the access network device corresponding to the first RAT; the terminal negotiates access layer security parameters between the terminal and the access network device corresponding to the second RAT.

[0154] Preferably, the terminal can negotiate the access layer security parameters between the terminal and the access network device corresponding to the first RAT through the AS SMC process, and the terminal can also negotiate the access layer security parameters between the terminal and the access network device corresponding to the second RAT through the AS SMC process.

[0155] The access layer security parameters may include at least one of the following: K gNBRRC integrity key, RRC encryption key, RRC integrity algorithm, RRC encryption algorithm, user plane integrity key, user plane encryption key, user plane integrity algorithm, user plane encryption algorithm.

[0156] After the terminal completes the access layer security parameter negotiation with the access network device corresponding to the first RAT and with the access network device corresponding to the second RAT, the terminal can enter the connected state under both the first RAT and the second RAT. That is, the terminal can enter the connected state through the connection between the access network device corresponding to the first RAT and the first core network device (which may include a NAS connection), and the terminal can also enter the connected state through the connection between the access network device corresponding to the second RAT and the first core network device (which may include a NAS connection).

[0157] In the existing initial registration process, the network needs to activate AS security context and NAS security context for the terminal respectively, for encryption and integrity protection of NAS signaling messages, AS messages, and user plane data. In merged registration, the network needs to activate AS security and NAS context for multiple access networks (or multiple legs) associated with multiple access terminals. That is, the terminal can simultaneously establish RRC connections with two access devices and select one of them to initiate a merged registration request. The access network device used to send the merged registration request can be randomly selected by the UE, or it can be selected by the UE based on information such as the current channel state and signal strength. Referring to Figure 7, taking the example of two communication systems sharing a single mobility management network element, another exemplary description of the terminal merged registration process is provided, specifically including:

[0158] Step 701a: The UE establishes an RRC connection with the access network device AN-1 (the access network device under the first RAT).

[0159] Step 701b: The UE establishes an RRC connection with the access network device AN-2 (the access network device under the second RAT).

[0160] Step 702: After the UE establishes an RRC connection with the access network device AN-1, it forwards the merged registration request (first merged registration request) to the MM (first core network device) through the access network device AN-1. The relevant description of the first merged registration request is the same as in the previous embodiment and will not be repeated.

[0161] Step 703: The UE performs two-way authentication with the network.

[0162] Step 704: Establish a logical NG connection (i.e., a second connection) between the MM and AN-2 to associate the UE. The specific processing of this step is the same as steps 602-603 illustrated in Figure 6 above, and will not be repeated. Here, the process of the MM establishing a logical NG connection to the access network device AN-2 to associate the UE can be executed by initiating an Initial Context Setup procedure. Ultimately, this establishes the necessary overall initial UE context for the UE at AN-2, including the PDU session context, security key, mobility restriction list, UE radio capabilities, and UE security capabilities. The security key is the key material of the NG-RAN node or next hop, which can be used to derive security keys for user layer traffic and RRC signaling information.

[0163] The UE may use the same NAS security context on different NAS connections, that is, use the same encryption algorithm, integrity protection algorithm, and key for encryption and integrity protection. After receiving the merge registration request and completing mutual authentication with the UE, the MM executes step 705. The MM sends a NAS SMC message to the UE through the access network device AN-1. The NAS SMC message activates the NAS security context (i.e., the first NAS security context) for the UE for all NAS signaling transmissions corresponding to the UE's access network devices.

[0164] Step 706 is the same as step 604, and will not be described again.

[0165] Furthermore, if the MM assigns different registration areas RA-1 and RA-2, and paging identifiers GUTI-1 and GUTI-2 to the UE for different access technologies (or different RATs), the access network devices AN-1 and AN-2 can respectively send the corresponding registration acceptance messages (containing the corresponding RA and GUTI) to the UE. In addition, the MM also registers with the UDM, and the UE context on the UDM records that the 5G and 6G mobility management network elements serving the UE are all MM.

[0166] Step 707: Access network device AN-1 negotiates with UE through the AS SMC procedure the algorithm and key for encryption and integrity protection of RRC and user plane.

[0167] In step 708, the access network device AN-2 negotiates with the UE through the AS SMC procedure the algorithm and key for encryption and integrity protection of RRC and user plane. After step 708, the UE enters connected state on both NAS connections, or on both legs, or under both RATs.

[0168] The above embodiments provide a method for activating NAS security context and AS security context for terminal connections on different access networks, so that RRC messages between the terminal and access network devices, signaling messages between the terminal and the core network, and user plane data can be encrypted and protected for integrity, ensuring the security of NAS messages sent by the terminal to the network on different NAS connections (e.g., sending session establishment requests to session management network elements through different access networks) and user plane data.

[0169] In one embodiment, before the terminal sends a first merge registration request to the first core network device through the access network device corresponding to the first RAT, the method further includes: the terminal establishing an RRC connection with the access network device corresponding to the first RAT.

[0170] In this embodiment, after the terminal establishes an RRC connection with the access network device corresponding to the first RAT, it performs the process of sending a first merge registration request.

[0171] The first merged registration request may carry at least one of the following: the identifier of the terminal, the area information corresponding to the access network device corresponding to the second RAT, the type information of the second RAT, the location information of the terminal, and the first indication information.

[0172] The terminal's identifier and the related description of the first indication information are the same as in the aforementioned embodiments, and will not be repeated here.

[0173] The area information corresponding to the access network device corresponding to the second RAT may include at least one of the following: the TAI (Tracking Area Identity) and the TAC (Tracking Area Code) corresponding to the access network device corresponding to the second RAT. The TAC corresponding to the access network device corresponding to the second RAT can be obtained from the broadcast message of the access network device corresponding to the second RAT, and the TAI corresponding to the access network device can be obtained from the TAC and PLMN identifier in the broadcast message of the access network device corresponding to the second RAT.

[0174] The type information of the second RAT may refer to the RAT type preferred by the terminal. The type information of the second RAT can be used to instruct the first core network device to select the access network device corresponding to the second RAT to establish an NG connection (i.e., the second connection) so that the terminal can forward NAS messages or NAS signaling from the access network device corresponding to the second RAT to the core network (i.e., the first core network device).

[0175] The location information of the terminal can be indicated by at least one of the following: TAI, cell identifier, geographic coordinates, etc. The geographic coordinates can be latitude and longitude coordinates.

[0176] It should be noted that the first merged registration request may also carry other content, such as slice identification information, etc. Here, we will not limit or exhaust all the possible contents that the first merged registration request may carry.

[0177] After the first core network device receives the first merge registration request, the terminal and the network side can perform two-way authentication, which will not be elaborated here.

[0178] After two-way authentication is completed between the terminal and the network, the first core network device can first determine the access network device corresponding to the second RAT, and then perform the process of establishing a second connection with the access network device corresponding to the second RAT. The method by which the first core network device determines the access network device corresponding to the second RAT can include: discovering or selecting the access network device corresponding to the second RAT based on at least one of the terminal's location information, the type information of the second RAT, and the area information corresponding to the access network device corresponding to the second RAT carried in the first merged registration request. For example, the first core network device can select the access network device corresponding to the second RAT closest to the terminal based on the terminal's location information and the type information of the second RAT; or, for example, the first core network device can select any access network device under the second RAT located within the TAC corresponding to the access network device corresponding to the second RAT based on the type information of the second RAT and the TAC corresponding to the access network device, and so on. The specific methods by which the first core network device selects or determines the access network device corresponding to the second RAT are not limited or exhaustively listed here.

[0179] Then, the first core network device can establish a second connection with the access network device corresponding to the second RAT. Specifically, before the first core network device sends the first merged registration acceptance message to the terminal through the access network device corresponding to the first RAT, the process further includes: the first core network device sending a connection establishment request to the access network device corresponding to the second RAT, wherein the connection establishment request is used by the access network device corresponding to the second RAT to establish a second connection; the first core network device receiving a connection establishment response sent by the access network device corresponding to the second RAT, wherein the connection establishment response is used to indicate the completion of establishing the second connection.

[0180] In addition to carrying at least one of the terminal's identifier and the identifier of the core network side corresponding to the second connection, the connection establishment request may also carry at least one of the following: access layer security parameters between the terminal and the access network device corresponding to the second RAT, wherein the access layer security parameters between the terminal and the access network device corresponding to the second RAT are used to protect messages transmitted between the terminal and the access network device corresponding to the second RAT; and fourth indication information, wherein the fourth indication information is used to indicate that the first core network device accepts the terminal's merged registration or to indicate that the terminal's registration type is merged registration. The relevant descriptions of the access layer security parameters are the same as in the aforementioned embodiments and will not be repeated.

[0181] In this embodiment, the content carried in the connection establishment response is the same as in the previous embodiment, and will not be repeated.

[0182] After the first core network device completes the establishment of the second connection, NAS security can be activated for the terminal through the NAS SMC process. The relevant procedures for activating NAS security are the same as those in the previous embodiments and will not be repeated.

[0183] After the terminal and the first core network device complete the NAS SMC process, the first core network device can send the first merge registration acceptance message to the terminal through the access network device corresponding to the first RAT.

[0184] The first merged registration acceptance message may carry at least one of the following: the identifier of the terminal, the identifier of the second connection, second indication information, one or more registration areas, and one or more NAS identifiers for paging. Further, the first merged registration acceptance message carries at least one of the following: the identifier of the access network device corresponding to the second RAT, the identifier of the cell corresponding to the access network device corresponding to the second RAT, and access layer security parameters between the terminal and the access network device corresponding to the first RAT, wherein the access layer security parameters between the terminal and the access network device corresponding to the first RAT are used to protect messages transmitted between the terminal and the access network device corresponding to the first RAT.

[0185] The first merged registration acceptance message carries the identifier of the access network device corresponding to the second RAT, which can be used to indicate that the network side has established an N2 context (i.e., established a second connection) for the terminal on the second RAT.

[0186] After receiving the first merge registration acceptance message, the terminal may also perform the following process: the terminal negotiates the access layer security parameters between the terminal and the access network device corresponding to the first RAT.

[0187] Furthermore, after the terminal receives the first merged registration acceptance message from the first core network device through the access network device corresponding to the first RAT, the method further includes: the terminal establishing an RRC connection with the access network device corresponding to the second RAT.

[0188] Optionally, the establishment of an RRC connection between the terminal and the access network device corresponding to the second RAT can be initiated or triggered based on the terminal's needs. For example, the terminal can establish an RRC connection with the access network device corresponding to the second RAT when it has uplink signaling and / or uplink data that needs to be transmitted through the access network device corresponding to the second RAT. The uplink signaling may include uplink NAS messages or signaling, such as session establishment / modification requests, etc.; the uplink data may be MO (Mobile Originated) data, or uplink data of any session, etc. The uplink signaling or uplink data is not limited or exhaustively listed here.

[0189] Optionally, the establishment of an RRC connection between the terminal and the access network device corresponding to the second RAT can be initiated or triggered by the network side. For example, if there is downlink signaling and / or downlink data on the network side that needs to be transmitted to the terminal through the access network device corresponding to the second RAT, the first core network device can send a paging message to the terminal through the access network device corresponding to the second RAT. This paging message can carry the NAS identifier for paging corresponding to the second RAT, or the NAS identifier for paging corresponding to the first RAT and the second RAT.

[0190] After receiving a paging message from the access network device corresponding to the second RAT, the terminal can establish an RRC connection with the access network device corresponding to the second RAT.

[0191] In the process of a terminal initiating the establishment of an RRC connection, the terminal may specifically send an RRC establishment request message to the access network device corresponding to the second RAT. This RRC establishment request message is used to request the establishment of an RRC connection.

[0192] The RRC establishment request message may also carry at least one of the terminal's identifier and first indication information.

[0193] Preferably, the identifier of the terminal can be the NAS identifier of the terminal.

[0194] Optionally, the content carried in the RRC establishment request message (i.e., at least one of the terminal's identifier and the first indication information) can be protected using access layer security parameters between the terminal and the access network device corresponding to the second RAT. For example, the content carried in the RRC establishment request message can be protected for integrity using the RRC integrity protection key and the RRC integrity protection algorithm and / or encrypted using the RRC encryption key and the RRC encryption algorithm.

[0195] Optionally, the content carried in the RRC establishment request message (i.e., at least one of the terminal's identifier and the first indication information) can be encapsulated as a NAS container, and the NAS container can be protected by access layer security parameters between the terminal and the access network device corresponding to the second RAT.

[0196] After receiving the RRC establishment request message, the access network device corresponding to the second RAT can perform integrity verification and / or decryption using access layer security parameters. If the integrity verification and / or decryption are successful, the access network device corresponding to the second RAT can establish an RRC connection with the terminal. The key and algorithm used by the access network device corresponding to the second RAT for integrity verification and decryption should correspond to the terminal, and therefore will not be elaborated upon.

[0197] Optionally, after successful integrity verification and / or decryption, the access network device corresponding to the second RAT can also negotiate access layer security parameters between the terminal and the access network device corresponding to the second RAT through the AS SMC procedure. Correspondingly, the terminal negotiates access layer security parameters between itself and the access network device corresponding to the second RAT through the AS SMC procedure. After the terminal and the access network device corresponding to the second RAT complete the AS SMC procedure, an RRC connection can be established.

[0198] In addition, if the access network device corresponding to the second RAT fails the integrity verification and / or decryption, the access network device corresponding to the second RAT can send a message to the terminal to refuse the establishment of the RRC connection. The message to refuse the establishment of the RRC connection can carry the reason for the refusal, such as the integrity verification failure and / or decryption failure.

[0199] Referring to Figure 8, taking the example of two communication systems sharing a single mobility management network element in their core networks, another exemplary illustration of the terminal merging registration process is provided, specifically including:

[0200] Step 800: The UE establishes an RRC connection with the access network device AN-2 (i.e., the access network device corresponding to the first RAT).

[0201] Step 801: The UE can send a merge registration request (first merge registration request) to the MM (first core network device) via AN-2, requesting registration management for multiple access points or multiple legs. The merge registration request message contains at least one of the following information: UE identifier; first indication information; UE location information, such as TAI, cell ID, latitude and longitude coordinates, etc., indicating the current location of the UE; RAT type, the type information of the UE's preferred RAT type, i.e., the type of the second RAT, used to instruct the MM to select the access network device corresponding to the RAT type and establish an NG connection with it, used by the UE to forward NAS messages to the core network on the access network device corresponding to the RAT type; target tracking area (i.e., the area information corresponding to the access network device corresponding to the second RAT), which can be the PLMN ID and / or TAC (tracking area code) obtained by the UE from the broadcast message of AN-1 (i.e., the access network device corresponding to the second RAT).

[0202] Step 802: The UE performs authentication and authorization with the core network.

[0203] In step 803, the MM can discover and select access network device AN-1 (i.e., the access network device corresponding to the second RAT) based on at least one of the UE's current location, RAT type, and target tracking area. The MM establishes a logical NG connection (second connection) associated with the UE with AN-1, and establishes corresponding UE contexts for the multiple access terminals on AN-1 and the MM. The MM initiates an Initial Context Setup procedure to access network device AN-1 to establish the necessary overall initial UE context for the UE at the AN-1 node, including UE identification information (including the UE's AS identifier, NAS identifier, etc.), PDU session context, security key, mobility restriction list, UE radio capabilities, and UE security capabilities. The security key is the key material of the NG-RAN node or next hop, which can be used to derive security keys for user layer traffic and RRC signaling information. In addition, the following parameters need to be sent to AN-1: a first key (or the public / private key corresponding to the first key), a first algorithm, a second key (or the public / private key corresponding to the second key), and a second algorithm, which are sent to AN-1 for AN-1 to encrypt messages sent to the UE or decrypt messages from the UE, and to perform integrity protection verification on messages from the UE; and a fourth indication information, which is used to instruct the UE to perform merge registration, or in other words, for the network to accept merge registration of the UE.

[0204] Step 804: The MM initiates the NAS SMC procedure to the UE via AN-2 to activate the NAS security context for the UE to perform integrity protection and encryption of NAS messages forwarded by the UE on all access network devices.

[0205] Step 805, the MM sends a merge registration acceptance message (i.e., the first merge registration acceptance message) to the UE, wherein the registration acceptance includes at least one of the following parameters:

[0206] The identification information of AN-1, such as global RAN node ID or cell ID, is used to indicate that the UE network has established an N2 context for the UE on the AN-1, that is, the logical NG connection associated with the UE.

[0207] The first key is used for messages between the UE and AN2 for integrity protection;

[0208] The first algorithm is used to protect the integrity of messages between the UE and AN2;

[0209] The second key is used to encrypt messages between the UE and AN2;

[0210] The second algorithm is used to encrypt messages between the UE and AN2;

[0211] UE identifier;

[0212] The second indication information is used to indicate that the network supports merged registration, or to indicate that the network side has established a logical NG connection associated with the UE between the access network device AN-1 and MM for the UE;

[0213] Identification information used to indicate to the network side that a logical NG connection associated with the UE has been established between the access network device AN-1 and MM for the UE;

[0214] NAS identifier used for paging.

[0215] Step 806: Access network device AN-2 negotiates with UE through the AS SMC procedure the algorithm and key for encryption and integrity protection of RRC and user plane.

[0216] Step 807: The UE establishes an RRC connection with AN-1.

[0217] Specifically, when the UE has uplink signaling (e.g., session establishment request, session modification request, etc.) or uplink data (MO data) that needs to be transmitted through AN-1, it can establish an RRC connection with AN-1. Alternatively, when the network side has downlink signaling or MT data that needs to be sent to the UE through AN-1, it can page the UE through AN-1. The paging message carries the identification information assigned to the UE by the MM in the merged registration acceptance request message, such as GUTI, TMSI, etc. When the UE establishes an RRC connection with AN-1, it needs to carry the UE NAS identifier (e.g., SUPI, CUCI, GUTI, etc.) and first indication information in the RRC establishment request message. The UE NAS identifier and first indication information can be directly included in the RRC message. The RRC message containing the NAS identifier and first indication information can be protected for integrity using a first key and / or encrypted using a second key. The UE NAS identifier and / or first indication information can also be included in the NAS container of the RRC message. In this case, the UE can protect the integrity of the NAS container using the first key and / or encrypt it using the second key.

[0218] Step 808: AN-1 and UE negotiate access layer security parameters through the AS SMC procedure.

[0219] Specifically, the access network device AN-1 uses the first key (or the corresponding public / private key), the first algorithm, the second key (or the corresponding public / private key), and the second algorithm obtained in the preceding steps to perform integrity protection verification and / or decryption on the received UE information. If integrity protection and / or decryption are successful, the access network device AN-1 negotiates with the UE through the AS SMC procedure to determine the encryption and integrity protection algorithms and keys used for RRC and user plane encryption. If integrity protection and / or decryption fail, the UE's RRC request is rejected, and the rejection message includes the reason for rejection: integrity protection and / or decryption failure.

[0220] By adopting the above embodiments, the terminal can first establish an RRC connection with one access network device, namely the access network device corresponding to the first RAT. After the terminal completes the merged registration, it can choose as needed whether to access the core network through another access network device, namely the access network device corresponding to the second RAT, to send NAS signaling and / or data. Similarly, the network side can also choose as needed whether to send NAS signaling and data to the terminal through another access network device. In this way, the terminal does not need to maintain RRC connections with multiple access network devices corresponding to multiple RATs, thereby reducing signaling consumption and improving the radio resource utilization of access network devices to a certain extent.

[0221] In some possible implementations, the control plane network elements of the core networks of the first and second communication systems are set separately, that is, the first core network equipment and the second core network equipment are different. For example, the first communication system and the second communication system are 5GS and 6GS, respectively. The control plane network elements of the core network of 5GS (i.e., 5GC) are the first core network equipment, and the control plane network elements of the core network of 6GS (i.e., 6GC) are the second core network equipment, or vice versa.

[0222] Before sending the first merge registration request, the terminal may include: establishing an RRC connection with the access network device corresponding to the first RAT, and establishing an RRC connection with the access network device corresponding to the second RAT. By establishing an RRC connection with the access network device corresponding to the second RAT, the terminal can obtain at least one of the following: the identifier of the access network device corresponding to the second RAT, the identifier of the cell corresponding to the access network device corresponding to the second RAT, and the area information corresponding to the access network device corresponding to the second RAT. The explanations regarding the establishment of the RRC connection and the various parameters obtained by the terminal are the same as in the aforementioned embodiments and will not be repeated.

[0223] In this scenario, the first merged registration request is used to request the establishment of a context for the terminal under the first RAT and the second RAT in the core network. Establishing a context for the terminal under the first RAT and the second RAT in the core network can include establishing a context for the terminal under the first RAT on a first core network device and establishing a context for the terminal under the second RAT on a second core network device.

[0224] Furthermore, the first merged registration request can be used to request the core network to perform registration management for the terminal in multiple RATs, or to request the core network to perform registration management for the terminal in multiple legs.

[0225] It should be noted that the first merged registration request can be used not only to request the establishment of a context for the terminal in the core network under the first RAT and the second RAT, but also to request the establishment of a context for the terminal in the core network under more other RATs. For example, the first merged registration request can be used to request the establishment of a context for the terminal in the core network under the first RAT, the second RAT, and the third RAT. The relevant processing for the third RAT or more other RATs is similar to that for the second RAT. Therefore, the following description mainly focuses on the second RAT and the first RAT, and will not describe the relevant processing for more other RATs. The following explanation will not be repeated.

[0226] The first merged registration request may carry at least one of the following: the terminal identifier, first indication information, the type information of the second RAT, the identifier of the access network device corresponding to the second RAT, and the area information corresponding to the access network device corresponding to the second RAT. The relevant descriptions of each item are the same as those in the foregoing embodiments and will not be repeated here.

[0227] It should be noted that the first merged registration request may also carry other content, such as slice identification information, etc. Here, we will not limit or exhaust all the possible contents that the first merged registration request may carry.

[0228] After the first core network device receives the first merge registration request, the terminal and the network side can perform two-way authentication, which will not be elaborated here.

[0229] After the terminal and the network side can perform two-way authentication, the first core network device can activate NAS security for the terminal through the NAS SMC process. Specifically, before the terminal receives the first merged registration acceptance message from the first core network device through the access network device corresponding to the first RAT, the process further includes: the terminal receiving a first NAS security mode command from the first core network device through the access network device corresponding to the first RAT, wherein the first NAS security mode command is used to activate a first NAS security context, and the first NAS security context is used to protect the NAS signaling transmitted by the terminal through the access network device corresponding to the first RAT, or the first NAS security context is used to protect the NAS signaling transmitted by the terminal through the access network device corresponding to the first RAT and the access network device corresponding to the second RAT. Before the terminal receives the first merged registration acceptance message from the first core network device through the access network device corresponding to the first RAT, the process further includes: the terminal receiving a first NAS security mode command from the first core network device through the access network device corresponding to the first RAT.

[0230] Since the two communication systems have different core network devices (control plane network elements), the first core network device is the first NAS security context sent by the terminal, which can be used to protect the NAS signaling transmitted by the terminal through the access network device corresponding to the first RAT. The protection includes encryption protection and / or integrity protection.

[0231] The first core network device can perform post-NAS security activation processing for the terminal via the NAS SMC procedure. This may further include: the first core network device determining whether merged registration is supported based on at least one of the following: local configuration, the terminal's subscription data, and network capabilities. The relevant descriptions of local configuration, terminal subscription data, and network capabilities are the same as in the aforementioned embodiments and will not be repeated here.

[0232] After determining that merged registration is supported, and before the first core network device sends a first merged registration acceptance message to the terminal through the access network device corresponding to the first RAT, the method further includes: the first core network device sending a second merged registration request to the second core network device, wherein the second merged registration request is used to request the establishment of a context for the terminal under the second RAT. Correspondingly, the second core network device receives the second merged registration request from the first core network device.

[0233] Optionally, the first core network device may select or determine the second core network device before sending the second merge registration request to the second core network device.

[0234] Specifically, the first core network device can select the second core network device based on the parameters carried in the first merge registration request.

[0235] For example, the first core network device can select a core network device whose service area includes or covers the area information of the access network device corresponding to the second RAT carried in the first merged registration request as the second core network device; or, the first core network device can select a core network device that supports the second RAT and whose service area covers the area information based on the type information of the second RAT and the area information of the access network device corresponding to the second RAT as the second core network device; or, the first core network device can select multiple core network devices that support the second RAT and whose service area covers the area information based on the type information of the second RAT and the area information of the access network device corresponding to the second RAT, and select one of them as the second core network device based on the load of the multiple core network devices. This is only an illustrative example. In actual processing, the first core network device can also use other methods to select the second core network device, which are not limited or exhaustive here.

[0236] In some embodiments, the content carried in the second merged registration request may be the same as that in the first merged registration request. For example, the second merged registration request carries at least one of the following: the identifier of the terminal, the identifier of the access network device corresponding to the second RAT, the identifier of the cell corresponding to the access network device corresponding to the second RAT, the area information corresponding to the access network device corresponding to the second RAT, the type information of the second RAT, the location information of the terminal, and first indication information, wherein the first indication information is used to indicate that the terminal is registered and managed in multiple RATs.

[0237] In this embodiment, the second merged registration request may carry at least one of the following: the terminal identifier, the first indication information, the type information of the second RAT, the identifier of the access network device corresponding to the second RAT, and the area information corresponding to the access network device corresponding to the second RAT.

[0238] After receiving the second merge registration request, the second core network device can also determine whether merge registration is supported based on at least one of the following: local configuration, terminal subscription data, and network capabilities. The local configuration can refer to the local configuration of the second core network device (such as operator configuration); the descriptions of the terminal subscription data and network capabilities are the same as in the aforementioned embodiments and will not be repeated.

[0239] After receiving the second merge registration request from the first core network device (e.g., after the second core network device determines that merge registration is supported), the second core network device further includes: sending a connection establishment request to the access network device corresponding to the second RAT, wherein the connection establishment request is used by the access network device corresponding to the second RAT to establish the second connection, and the second connection is used for transmitting NAS signaling corresponding to the terminal between the access network device corresponding to the second RAT and the second core network device; the second core network device receives a connection establishment response sent by the access network device corresponding to the second RAT, wherein the connection establishment response is used to indicate the completion of establishing the second connection.

[0240] The second connection can be used to transmit NAS signaling corresponding to the terminal between the access network device corresponding to the second RAT and the second core network device. Before sending a connection establishment request to the access network device corresponding to the second RAT, the second core network device can also assign a unique identifier on the core network side to the second connection. The identifier assigned by the second core network device to the second connection can be called the identifier on the second core network device side corresponding to the second connection.

[0241] The connection establishment request can be an N2 message between the second core network device and the access network device corresponding to the second RAT. The N2 message can be any one of the following: downlink NAS transmission message, initial context establishment, or connection establishment indication.

[0242] The connection establishment request may carry at least one of the following: the terminal's identifier, or the identifier of the core network side corresponding to the second connection. In this embodiment, the identifier of the core network side corresponding to the second connection may be assigned by the second core network device and can be referred to as the identifier of the second core network device side corresponding to the second connection.

[0243] After receiving the connection establishment request, the access network device corresponding to the second RAT can also assign a unique identifier to the second connection. The unique identifier assigned by the access network device corresponding to the second RAT to the second connection is called the identifier assigned to the second connection by the access network device corresponding to the second RAT.

[0244] The connection establishment response may carry at least one of the following: the identifier of the terminal, the identifier of the access network device corresponding to the second RAT corresponding to the second connection, and the identifier of the core network corresponding to the second connection.

[0245] After the second core network device completes the establishment of the second connection, it can activate NAS security for the terminal through the NAS SMC procedure. Specifically, after the second core network device receives the connection establishment response sent by the access network device corresponding to the second RAT, it may further include: the second core network device sending a second NAS security mode command to the terminal through the access network device corresponding to the second RAT, wherein the second NAS security mode command is used to activate a second NAS security context, and the second NAS security context is used to protect the NAS signaling transmitted by the terminal through the access network device corresponding to the second RAT. Correspondingly, before the terminal receives the first merged registration acceptance message from the first core network device through the access network device corresponding to the first RAT, it further includes: the terminal receiving the second NAS security mode command from the second core network device through the access network device corresponding to the second RAT, wherein the second NAS security mode command is used to activate a second NAS security context, and the second NAS security context is used to protect the NAS signaling transmitted by the terminal through the access network device corresponding to the second RAT.

[0246] The second NAS security context may include at least one of the following shared by the terminal and the second core network device: NAS encryption key, NAS integrity protection (hereinafter referred to as integrity protection) key, NAS encryption algorithm, and NAS integrity protection algorithm.

[0247] After receiving the second NAS security mode command, the terminal can also send the second NAS security mode completion message to the second core network device through the access network device corresponding to the second RAT. Here, we will not limit or exhaustively list the messages and their contents that may be transmitted in the NAS SMC process.

[0248] After the second core network device sends the second NAS security mode command to the terminal through the access network device corresponding to the second RAT, the method further includes: the second core network device sending a second merge registration acceptance message to the first core network device, wherein the second merge registration acceptance message is used by the first core network device to determine that the second core network device has completed registration. After the first core network device sends a second merge registration request to the second core network device, the method further includes: the first core network device receiving a second merge registration acceptance message from the second core network device, wherein the second merge registration acceptance message is used by the first core network device to determine that the second core network device has completed registration.

[0249] The second merge registration acceptance message carries at least one of the following: the identifier of the terminal, third indication information indicating that the second core network device supports merge registration, the registration area corresponding to the second RAT, and the NAS identifier for paging corresponding to the second RAT.

[0250] The NAS identifier for paging corresponding to the second RAT is assigned by the second core network device, and the specific assignment method is not limited here.

[0251] The registration area corresponding to the second RAT is allocated by the second core network device. The registration area corresponding to the second RAT may include a list of TAIs corresponding to the second RAT, and the list of TAIs may include one or more TAIs.

[0252] After the terminal and the second core network device complete the NAS SMC process, and before the second core network device sends the second merge registration acceptance message to the first core network device, the second core network device may also establish a local context (terminal context or UE context) for the terminal under the second RAT. The context of the terminal under the second RAT may include at least one of the following: the NAS identifier for paging corresponding to the second RAT, the registration area corresponding to the second RAT, and the second NAS security context (or security parameters). The process of the second core network device establishing the terminal context is not limited here.

[0253] Optionally, after the second core network device sends a second merged registration acceptance message to the first core network device, the method further includes: the second core network device sending a registration message to the UDM, wherein the registration message carries at least one of the following: the identifier of the terminal, the identification information of the second core network device, the type information of the second RAT, and a sixth indication information, wherein the sixth indication information is used to indicate that the registration type of the terminal is merged registration. That is, the second core network device can also register with the UDM, and record in the UE context on the UDM that the second core network device is a mobility management network element under the second communication system (or the second RAT of the second communication system) serving the terminal. The content recorded by the second core network device in the UE context of the UDM may include at least one of the following: the identification information of the second core network device and the type information of the second RAT.

[0254] The identification information of the second core network device may include at least one of the following: the ID of the second core network device, the name of the second core network device, the IP (Internet Protocol) address of the second core network device, the MAC (Media Access Control) address of the second core network device, the FQDN (Fully Qualified Domain Name) of the second core network device, etc.

[0255] After receiving the second merge registration acceptance message, the first core network device can send the first merge registration acceptance message to the terminal through the access network device corresponding to the first RAT.

[0256] The first merged registration acceptance message may carry at least one of the following: the terminal's identifier, second indication information, third indication information, one or more registration areas, and one or more NAS identifiers for paging.

[0257] In addition to indicating the completion of the establishment of the first connection and the second connection, the second indication information can also be used to indicate that the network side supports merged registration or that the first core network device supports merged registration.

[0258] The third instruction information is contained in the second merged registration acceptance message.

[0259] One or more registration areas may include: the registration area corresponding to the first RAT and the registration area corresponding to the second RAT.

[0260] One or more NAS identifiers for paging include: a NAS identifier for paging corresponding to a first RAT and a NAS identifier for paging corresponding to a second RAT.

[0261] Because the control network elements on the core network side of the first and second communication systems are different, the first core network device allocates a registration area corresponding to the first RAT and a NAS identifier for paging corresponding to the first RAT; the second core network device allocates a registration area corresponding to the second RAT and a NAS identifier for paging corresponding to the second RAT. In the first merged registration acceptance message, the registration area and NAS identifier allocated by the first and second core network devices respectively can be sent to the terminal.

[0262] Optionally, the first merged registration acceptance message can be encrypted and / or fully protected by the first NAS security context. This embodiment does not limit the specific processing of encrypting and / or fully protecting the first merged registration acceptance message using the first NAS security context. In this case, the terminal can use the first NAS security context to perform full protection verification and / or decryption of the first merged registration acceptance message. If the full protection verification and / or decryption are successful, the merged registration is determined to be successful, and the terminal obtains the various parameters allocated to it by the network side.

[0263] Optionally, the registration area corresponding to the second RAT and the NAS identifier for paging corresponding to the second RAT carried in the second merged registration acceptance message can be carried by the NAS container. The NAS container can be protected by the second NAS security context (encryption and / or integrity protection). Here, the specific processing of protecting the NAS container by the second NAS security context is not limited.

[0264] The first merged registration acceptance message may carry the NAS container, and may also carry at least one of the following: the terminal's identifier, second indication information, third indication information, the registration area corresponding to the first RAT, and the NAS identifier for paging corresponding to the first RAT. At least one of the terminal's identifier, second indication information, third indication information, the registration area corresponding to the first RAT, and the NAS identifier for paging corresponding to the first RAT may be encrypted and / or fully protected by the first NAS security context, or this part may not be fully protected and / or encrypted. This embodiment does not limit the specific processing of encrypting and / or fully protecting the first merged registration acceptance message using the first NAS security context.

[0265] In this scenario, the terminal can use the second NAS security context to perform integrity verification and / or decryption of the NAS container carried in the first merged registration accept message. If the integrity verification and / or decryption are successful, it is determined that the second core network device has successfully registered the terminal, and the terminal obtains the various parameters assigned to it by the second core network device. Alternatively, the terminal can use the first NAS security context to perform integrity verification and / or decryption of the remaining content carried in the first merged registration accept message. If the integrity verification and / or decryption are successful, it is determined that the terminal has successfully merged and registered with the first core network device, and the terminal obtains the various parameters assigned to it by the first core network device.

[0266] After the terminal receives the first merged registration acceptance message from the first core network device through the access network device corresponding to the first RAT, it further includes at least one of the following: the terminal negotiates access layer security parameters between the terminal and the access network device corresponding to the first RAT; the terminal negotiates access layer security parameters between the terminal and the access network device corresponding to the second RAT.

[0267] Preferably, the terminal can negotiate the access layer security parameters between the terminal and the access network device corresponding to the first RAT through the AS SMC process, and the terminal can also negotiate the access layer security parameters between the terminal and the access network device corresponding to the second RAT through the AS SMC process.

[0268] Optionally, after the first core network device sends a first merged registration acceptance message to the terminal through the access network device corresponding to the first RAT, the method further includes: the first core network device sending a registration message to the UDM, wherein the registration message carries at least one of the following: the identifier of the terminal, the identification information of the first core network device, a fifth indication information, the type information of the first RAT, and information indicating that the associated RAT type is the second RAT, wherein the fifth indication information indicates that the registration type of the terminal is merged registration. That is, if the first core network device accepts merged registration, it can also register with the UDM, and record in the UE context on the UDM that the first core network device is a mobility management network element under the first communication system (or the first RAT of the first communication system) serving the terminal, and can also record that the second RAT is the associated RAT type information. The content recorded by the first core network device in the UE context of the UDM may include at least one of the following: the identification information of the first core network device, the type information of the first RAT, and the type information of the second RAT.

[0269] It should be understood that the first core network device may also associate and record the identification information of the second core network device in the UE context of the UDM, that is, the UDM can record that the first core network device is a mobility management network element under the first communication system (or the first RAT of the first communication system) serving the terminal, and the second core network device is a mobility management network element under the second communication system or the second RAT of the second communication system serving the terminal.

[0270] It should be noted that the first core network device can also establish a terminal context (terminal context or UE context) under the first RAT locally. The terminal context under the first RAT may include at least one of the following: the NAS identifier for paging corresponding to the first RAT, the registration area corresponding to the first RAT, the first NAS security context (or security parameters), and the associated RAT type being the second RAT. The process of establishing a terminal context by the first core network device is not limited here.

[0271] In some examples, if the second core network device determines that it does not support merged registration, or if the second core network device fails to establish a second connection with the access network device corresponding to the second RAT, or if the second core network device fails to execute the NAS SMC procedure (or process), the second core network device sends a second merged registration rejection message to the first core network device. This second merged registration rejection message may carry at least one of the following: the identifier of the terminal, a rejection reason, etc., which may include at least one of the following: the second core network device does not support merged registration, the second core network device fails to establish a connection with the access network device corresponding to the second RAT, or the NAS SMC procedure fails to execute.

[0272] In some examples, when the first core network device determines that it does not support merged registration, or when the first core network device receives a second merged registration rejection message, the process may further include: the first core network device sending a first merged registration rejection message to the terminal through the access network device corresponding to the first RAT. This first merged registration rejection message may carry at least one of the following: the terminal's identifier, a rejection reason, etc. The rejection reason may include at least one of the following: the second core network device does not support merged registration, the second core network device failed to establish a connection with the access network device corresponding to the second RAT, the NAS SMC process failed to execute, or the first core network device does not support merged registration, etc.

[0273] In some examples, when the first core network device receives a second merged registration rejection message, the first core network device may accept partial registration based on operator configuration (or local configuration) and / or the terminal's subscription information. That is, the first core network device may accept registration on the access network device corresponding to the first RAT (i.e., establishing a terminal context under the first RAT only on the first core network device side). The processing of the first core network device may further include: the first core network device sending a partial registration acceptance message to the terminal through the access network device corresponding to the first RAT. This partial registration acceptance message may carry at least one of the following: the terminal's identifier, a seventh indication information, the registration area corresponding to the first RAT, and the NAS identifier for paging corresponding to the first RAT. The seventh indication information may be used to indicate at least one of the following: the first core network device accepts registration under the first RAT; registration on the access network device corresponding to the first RAT is successfully accepted; the second core network device does not support merged registration; or the first core network device supports merged registration.

[0274] Referring to Figure 9, taking a scenario where the mobility management network elements (MMIs) of the core networks of two communication systems are set up separately and are independent of each other, an exemplary description of the terminal merge registration process is provided. As shown in Figure 9, the 6G MMI (6G MM, the second core network device) and the 5G MMI (AMF, the first core network device) are two different network elements. The UE can send a merge registration request to one of the MMIs (AMF), which then forwards the merge registration request to the other MMI (6G MM). The AMF and 6G MM then assign the UE information such as the 5G NAS identifier, 6G NAS identifier, 5G registration area, and 6G registration area for paging. This enables the UE to merge registration on the 6G core network and the 5G core network. Specifically, this includes:

[0275] Step 901a: The UE establishes an RRC connection with the 5G-RAN (the access network equipment corresponding to the first RAT).

[0276] Step 901b: The UE establishes an RRC connection with the 6G-RAN (the access network device corresponding to the second RAT). The UE obtains at least one of the following: the 6G-RAN's identification information, tracking area (i.e., the area information in the aforementioned embodiment), and cell ID.

[0277] In step 902, the UE forwards the merge registration request (i.e., the first merge registration request) to the AMF via the 5G-RAN. Alternatively, the UE can send the merge registration request to the 6G MM via the 6G-RAN. That is, the UE can randomly select either the 5G-RAN or the 6G-RAN to send the merge registration request, or it can select an access network device with better channel conditions based on signal strength measurements such as SINR and RSRP.

[0278] The merge registration request message contains the following parameters:

[0279] UE identification information, such as SUPI, SUCI, GUTI, etc.;

[0280] The first instruction information instructs the UE to perform combined registration for its multiple access technologies (or multiple RATs) or instructs the UE to support combined registration;

[0281] One or more tracking area identifiers, indicating the TAI or TAC corresponding to 6G, wherein the TAI can be obtained from the TAC and PLMN identifier broadcast by the access network device 6G-RAN;

[0282] One or more access network device identifiers, in this embodiment, are 6G-RAN identifiers. The UE can obtain the 6G-RAN identifier information by the cell ID and the access network identifier length.

[0283] One or more RAT types, used to indicate the type information of multiple RATs that the UE requests to merge and register;

[0284] Slice identification information.

[0285] Step 903: The UE authenticates with the core network.

[0286] Step 904: The AMF establishes a 5G NAS security context (i.e., the first NAS security context in the aforementioned embodiment) between the AMF and the UE through the NAS SMC procedure.

[0287] Step 905: The AMF determines whether merged registration is supported based on at least one of the local configuration, UE subscription data, and network capabilities. If supported, the merged registration request (i.e., the second merged registration request in the aforementioned embodiment) is forwarded to the 6G MM.

[0288] Here, the AMF can select a suitable 6G MM based on the parameters carried in the merged registration request. For example, when selecting a 6G MM, the AMF can also consider the service area of ​​the 6G MM, i.e., the service area covers the target tracking area, and / or the load balancing of the 6G MM.

[0289] Step 906: After receiving the merged registration request message, the 6G MM determines whether merged registration is supported based on at least one of the following: local configuration, UE subscription data, and network capabilities. If supported, the 6G MM establishes a connection with the 6G RAN (i.e., a second connection) through the initial context establishment process. For example, the MM can determine the 6G RAN and establish a connection with it (i.e., a second connection) based on the parameters carried in the merged registration request.

[0290] Step 907: The 6G MM sends a NAS SMC message to the UE via the 6G-RAN, and a 6G NAS security context (i.e., the second NAS security context in the aforementioned embodiment) is established between the 6G MM and the UE.

[0291] Step 908: The 6G MM establishes a UE context for the UE and sends a registration acceptance message (i.e., the second merged registration acceptance message) to the AMF. The registration acceptance message contains the following parameters: UE identification information; third indication information, used to indicate that the 6G MM supports merged registration; 6G-GUTI (i.e., the NAS identifier for paging corresponding to the second RAT), the NAS identifier allocated by the 6G MM for paging the UE; 6G-Registration Area (i.e., the registration area corresponding to the second RAT), the 6G registration area allocated by the 6G MM for the UE, the registration area only contains the TAI list corresponding to 6G.

[0292] Here, the 6G-GUTI and 6G-registration areas can be in a 6G NAS container, with integrity protection and / or encryption provided by the 6G NAS context.

[0293] Step 909: After receiving the registration acceptance message from the 6G MM, the AMF sends a merged registration acceptance message (i.e., the first merged registration acceptance message) to the UE via the 5G-RAN. The merged registration acceptance message includes at least one of the following parameters:

[0294] The second instruction information indicates that the AMF supports merged registration, or it can be used to indicate that the network side supports merged registration;

[0295] The third instruction indicates that 6G MM supports merged registration;

[0296] 5G-GUTI (i.e., the NAS identifier for paging corresponding to the first RAT), the NAS identifier for paging allocated by the AMF;

[0297] 5G registration area (i.e., the NAS identifier for paging corresponding to the first RAT), the 5G registration area allocated by AMF to the UE, the registration area only contains the TAI list corresponding to 5G;

[0298] 6G-GUTI;

[0299] 6G - Registration Area.

[0300] If the 6G-GUTI and 6G-registration area in the registration acceptance message are not encapsulated in a 6G NAS container, the merged registration acceptance message can directly carry the 6G-GUTI and 6G-registration area; if the 6G-GUTI and 6G-registration area in the registration acceptance message are encapsulated in a 6G NAS container and the 6G NAS container is protected for integrity and / or encrypted by the 6G NAS context, the merged registration acceptance message can carry the 6G NAS container.

[0301] The merged registration acceptance message is protected for integrity and / or encrypted by the 5G NAS security context.

[0302] In addition, the 6G MM is registered with the UDM, and the 6G MM is recorded in the UE context on the UDM as the 6G mobility management element serving the UE. If the AMF accepts the registration request, it will register with the UDM, and the 5G mobility management element serving the UE will be recorded in the UE context on the UDM as the AMF.

[0303] Step 910: The 5G-RAN negotiates with the UE through the AS SMC procedure the algorithm and key for encryption and integrity protection of RRC and user plane.

[0304] Step 911: The 6G-RAN negotiates with the UE through the AS SMC procedure the algorithm and key for encryption and integrity protection of RRC and user plane.

[0305] Additionally, in step 906, if the 6G MM does not support merged registration or cannot connect to the 6G-RAN, steps 906-907 are skipped.

[0306] Optionally, if the 6G MM does not support merged registration, or cannot connect to the 6G-RAN (i.e., the second connection establishment fails), or the 6G NAS SMC procedure fails, a merged registration rejection message is sent to the AMF. The merged registration rejection message includes the following parameters: UE identification information; rejection reason: for example, any one of the following: 6G MM does not support merged registration, the connection establishment between the 6G MM and the target 6G-RAN fails, or the 6G NAS SMC procedure fails.

[0307] In step 909, if the AMF does not support it, or if the AMF receives a merge registration rejection message from the 6G MM, then a merge registration rejection message is sent to the UE. The merge registration rejection message includes the following parameters: UE identifier; rejection reason: for example, at least one of the following: 6G MM does not support merge registration, connection establishment between 6G MM and the target 6G-RAN failed, 6G NAS SMC procedure failed, or AMF does not support merge registration.

[0308] If the AMF receives a merge registration rejection message from the 6G MM, the AMF may also send a partial registration acceptance message to the UE based on the operator configuration and / or UE subscription information. The registration acceptance message includes the following information: UE identifier; fourth indication information, used to indicate that the AMF supports merge registration while the 6G MM does not support merge registration, or used to indicate that only the AMF accepted the registration request; 5G GUTI; 5G registration area.

[0309] In some alternative examples, in step 905 above, when the AMF forwards the merge registration request to the 6G MM, it may also carry at least one of the following in the merge registration request: second indication information, indicating that the AMF supports merge registration, or used to indicate that the network side supports merge registration; 5G-GUTI (i.e., the NAS identifier for paging corresponding to the first RAT); 5G registration area (i.e., the NAS identifier for paging corresponding to the first RAT).

[0310] In this case, step 909 can be replaced by: the 6G MM (i.e., the second core network device) sending a merged registration acceptance message (i.e., the first merged registration acceptance message) to the UE via the 6G-RAN (i.e., the access network device corresponding to the second RAT). The merged registration acceptance message includes at least one of the following parameters: second indication information, third indication information, 5G-GUTI, 5G registration area, 6G-GUTI, and 6G-registration area. Optionally, the merged registration acceptance message can be protected for integrity and / or encrypted by the 6G NAS security context.

[0311] In this alternative example, the relevant descriptions of the remaining steps 901-904, 906-908, and 910-911 are the same as those in the above example and will not be repeated.

[0312] The above embodiments provide a method for terminal merged registration in scenarios with different mobility management network elements in multiple communication systems. This scheme allows a terminal to complete registration in multiple communication systems (or the core networks of multiple communication systems, or multiple RATs of multiple communication systems) through a single registration process. In this scheme, multiple mobility management network elements of multiple communication systems assign the terminal a NAS identifier and registration area corresponding to different RATs for paging, and configure multiple sets of NAS security contexts. This allows subsequent interactions between the terminal and the core networks of each communication system to be independent, and the terminal and network can select appropriate access network devices to send signaling messages and data as needed.

[0313] In some embodiments, the second merged registration request includes parameters or content from the first merged registration request. For example, the second merged registration request may carry at least one of the following: the terminal identifier, first indication information, type information of the second RAT, the identifier of the access network device corresponding to the second RAT, and the area information corresponding to the access network device corresponding to the second RAT. The descriptions of each parameter are the same as in the foregoing embodiments and will not be repeated here.

[0314] In this embodiment, the second merged registration request also carries at least one of the following: the NAS identifier for paging corresponding to the first RAT, and the registration area corresponding to the first RAT.

[0315] In other words, before sending the second merge registration request to the second core network device, the first core network device allocates the NAS identifier for paging corresponding to the first RAT and the registration area corresponding to the first RAT, and then carries the NAS identifier for paging corresponding to the first RAT and the registration area corresponding to the first RAT allocated by the first core network device in the second merge registration request.

[0316] It should be noted that this is merely an illustrative example, and in actual processing, the second merged registration request may carry other content, which is not limited or exhaustively listed here.

[0317] After receiving the second merge registration request, the second core network device can also determine whether merge registration is supported based on at least one of the following: local configuration, terminal subscription data, and network capabilities. If merge registration is supported, the second core network device can establish a second connection with the access network device corresponding to the second RAT. The processing related to establishing the second connection is the same as in the aforementioned embodiments and will not be repeated.

[0318] After the second core network device sends the second NAS security mode command to the terminal through the access network device corresponding to the second RAT, the method further includes: the second core network device sending a second merge registration acceptance message to the first core network device, wherein the second merge registration acceptance message is used by the first core network device to determine that the second core network device has completed registration. After the first core network device sends a second merge registration request to the second core network device, the method further includes: the first core network device receiving a second merge registration acceptance message from the second core network device, wherein the second merge registration acceptance message is used by the first core network device to determine that the second core network device has completed registration.

[0319] The second merged registration acceptance message carries at least one of the following: a third indication indicating that the second core network device supports merged registration, the registration area corresponding to the first RAT and the second RAT, and the NAS identifier for paging corresponding to the first RAT and the second RAT.

[0320] The registration areas corresponding to the first RAT and the second RAT are determined by the second core network device.

[0321] Optionally, the second core network device may use the registration area corresponding to the first RAT carried in the second merged registration request as the registration area corresponding to both the first RAT and the second RAT. Optionally, the second core network device may update a combined registration area, which includes the TAI list corresponding to the first RAT (or a TAI list specific to the first RAT) and the TAI list corresponding to the second RAT (or a TAI list specific to the second RAT). This combined registration area is the registration area corresponding to both the first RAT and the second RAT.

[0322] The NAS identifiers for paging corresponding to the first RAT and the second RAT are determined by the second core network device.

[0323] Optionally, the second core network device may use the NAS identifier for paging corresponding to the first RAT carried in the second merge registration request as the NAS identifier for paging corresponding to both the first and second RATs. Optionally, the second core network device may generate an identifier different from the NAS identifier for paging corresponding to the first RAT, and use the newly generated identifier as the NAS identifier for paging corresponding to both the first and second RATs. Optionally, the second core network device may generate the NAS identifier for paging corresponding to the second RAT, and merge the NAS identifier for paging corresponding to the second RAT and the NAS identifier for paging corresponding to the first RAT to obtain a combined NAS identifier for paging, which is the NAS identifier for paging corresponding to both the first and second RATs.

[0324] Here, the second core network device can also establish a terminal context (terminal context or UE context) under the second RAT locally. The terminal context under the second RAT may include at least one of the following: the NAS identifier for paging corresponding to the first RAT and the second RAT, the registration area corresponding to the first RAT and the second RAT. The process of establishing the terminal context by the second core network device is not limited here.

[0325] Optionally, after the second core network device sends the second merged registration acceptance message to the first core network device, the process further includes: the second core network device sending a registration message to the UDM. The process of the first core network device registering with the UDM is the same as in the previous embodiments and will not be described again.

[0326] In other words, the second core network device can also register with the UDM, and the UE context on the UDM records the second core network device as a mobility management network element under the second communication system (or the second RAT of the second communication system) serving the terminal. The content recorded by the second core network device in the UE context of the UDM may include at least one of the following: the identification information of the second core network device and the type information of the second RAT.

[0327] After receiving the second merge registration acceptance message, the first core network device can send the first merge registration acceptance message to the terminal through the access network device corresponding to the first RAT.

[0328] The first merged registration acceptance message may carry at least one of the following: the terminal's identifier, second indication information, third indication information, one or more registration areas, and one or more NAS identifiers for paging.

[0329] One or more registration regions may include: the registration regions corresponding to the first RAT and the second RAT.

[0330] One or more NAS identifiers for paging include: NAS identifiers for paging corresponding to the first RAT and the second RAT.

[0331] After the terminal receives the first merged registration acceptance message from the first core network device through the access network device corresponding to the first RAT, the method further includes at least one of the following: the terminal negotiates access layer security parameters between itself and the access network device corresponding to the first RAT; the terminal negotiates access layer security parameters between itself and the access network device corresponding to the second RAT. The specific processing of the terminal negotiating access layer security parameters is the same as in the aforementioned embodiments and will not be repeated here.

[0332] Optionally, after the first core network device sends the first merged registration acceptance message to the terminal through the access network device corresponding to the first RAT, the process further includes: the first core network device sending a registration message to the UDM. The process of the first core network device registering with the UDM is the same as in the previous embodiments and will not be described again.

[0333] It should be noted that the first core network device can also establish a local context (terminal context or UE context) for the terminal under the first RAT. The content of the context of the terminal under the first RAT may be similar to that in the aforementioned embodiments, and will not be described in detail.

[0334] If the second core network device determines that it does not support merged registration, or the second core network device fails to establish a second connection with the access network device corresponding to the second RAT, or the second core network device fails to execute the NAS SMC process (or procedure), the processing performed by the second core network device is the same as in the aforementioned embodiments, and will not be described again.

[0335] If the first core network device determines that it does not support merged registration, or if the first core network device receives a second merged registration rejection message, the processing performed by the first core network device is similar to that in the aforementioned embodiments, and will not be described in detail.

[0336] Referring to Figure 10, taking a scenario where the mobility management network elements (MMIs) of the core networks of two communication systems are set up separately and are independent of each other, another exemplary explanation of the terminal merge registration process is provided. As shown in Figure 10, the 6G MMI (6G MM, the second core network device) and the 5G MMI (AMF, the first core network device) are two different network elements. The UE can send a merge registration request to one of the MMIs (AMF), and the MMI (AMF) forwards the merge registration request to the other MMI (6G MM). The AMF and 6G MM jointly allocate information such as the NAS identifier for paging and the registration area for the UE. This enables the UE to merge registration on the 6G core network and the 5G core network. Specifically, this includes:

[0337] Steps 1001 to 1004 are the same as steps 901 to 904 in the previous example, and will not be repeated here.

[0338] Step 1005: If the AMF supports merged registration, it assigns a GUTI for paging and a registration area (i.e., the NAS identifier and registration area for paging corresponding to the first RAT) to the UE. Based on the parameters carried in the received merged registration request message, local configuration information, UE subscription messages, etc., it discovers and selects a suitable 6G MM, and then sends a merged registration request message (i.e., a second merged registration request) to the 6G MM. The merged registration request includes at least one of the following parameters: UE identification information; first indication information; one or more tracking area identifiers, indicating the TAI or TAC corresponding to the 6G-RAN (i.e., the access network device corresponding to the second RAT). The TAI can be obtained from the TAC and PLMN identifier broadcast by the 6G-RAN; one or more access network device identifiers, which in this embodiment is the 6G-RAN identifier. The UE can obtain the 6G-RAN identifier information through the cell ID and the access network identifier length; one or more RATs. type, used to indicate the radio access technology type corresponding to the access network device for which the UE requests to merge registration; slice identification information; at least one of the following parameters assigned to the UE by the AMF: 5G-GUTI (NAS identifier for paging corresponding to the first RAT), 5G-registration area (registration area corresponding to the first RAT), the 5G-registration area contains the TAI list corresponding to the 5G RAT.

[0339] Here, if the AMF does not support merged registration, a merged registration rejection message is sent to the UE. The rejection message includes the UE identifier and the rejection cause.

[0340] Step 1006 is the same as step 906 in the previous example, and will not be described again.

[0341] Step 1007: If the 6G MM supports the merged registration request, the 6G MM establishes a UE context for the UE locally (including information such as the identifier for paging the UE, registration area, and security parameters), and sends a merged registration acceptance message (i.e., the second merged registration acceptance message) to the AMF; otherwise, the 6G MM sends a merged registration rejection message to the AMF, the rejection message containing the UE identifier and a rejection cause indicating that the 6G MM does not support merged registration.

[0342] The merged registration acceptance message includes at least one of the following parameters:

[0343] GUTI* (i.e., the NAS identifier for paging corresponding to the first RAT and the second RAT), 6G MM can still use the 5G-GUTI allocated by AMF and record it in the UE context on 6G MM, or it can use a new 6G GUTI, or obtain a new combined GUTI based on 5G-GUTI and 6G-GUTI, which includes 5G-GUTI and 6G-GUTI;

[0344] RA* (registration area) (i.e., the registration area corresponding to the first RAT and the second RAT), 6G MM can still use the registration area allocated by AMF and record it in the UE context on 6G MM, or it can update a combined RA containing the 5G RAT specific TAI list and the 6G RAT specific TAI list.

[0345] The third instruction is used to indicate that 6G MM supports merged registration.

[0346] Step 1008: The 6G MM is registered with the UDM. In the UE context on the UDM, the 6G MM ID is recorded as the 6G Mobility Management Network Element serving the UE. The message carries the UE identifier, 6G MM ID, and indication information to indicate that the UE has performed merge registration.

[0347] Step 1009: After receiving the merged registration acceptance message from the 6G MM, the AMF sends a merged registration acceptance message (i.e., the first merged registration acceptance message) to the UE through the 5G-RAN (i.e., the access network equipment corresponding to the first RAT). The merged registration acceptance message contains at least one of the following information:

[0348] Combined GUTI (i.e., the NAS identifier for paging corresponding to the first RAT and the second RAT), identification information for paging UE shared by AMF and 6G MM;

[0349] Combined registration area (i.e., the registration area corresponding to the first RAT and the second RAT), registration area shared by AMF and 6G MM, including one or more tracking areas corresponding to 6G radio access technology (RAT) and / or one or more tracking areas corresponding to 5G radio access technology (RAT);

[0350] The second instruction indicates that the AMF supports merged registration or the network side supports merged registration.

[0351] The third instruction indicates that 6G MM supports merged registration.

[0352] Step 1010: If the AMF receives the registration request, it will register with the UDM and record the 5G mobility management network element serving the UE as the AMF in the UE context on the UDM. The message carries the UE identifier, AMF ID, and indication information to indicate that the UE has performed merge registration.

[0353] Steps 1011 to 1012 are the same as steps 910 to 911 in the previous example, and will not be repeated.

[0354] Additionally, if the AMF receives a merge registration rejection message from the 6G MM in step 1009, the AMF may also determine to accept partial registration based on operator configuration and / or UE subscription information, and send a partial registration acceptance message to the UE. The registration acceptance message includes at least one of the following: UE identifier; fourth indication information, used to indicate that the AMF supports merge registration while the 6G MM does not support merge registration, or used to indicate that only the AMF accepted the registration request; 5G GUTI; 5G registration area.

[0355] In the above embodiments, the same NAS identifier and registration area for paging, as well as the same set of NAS security contexts, are allocated to the terminals on multiple core network devices of multiple communication systems under different RATs. This not only saves the terminal's storage space but also avoids the need for wireless mapping of the NAS identifier and NAS security context for paging when the terminal is interworking between multiple communication systems or networks, reducing the workload of the network and the terminal. Furthermore, using the same registration area eliminates the need for frequent registration update procedures to update the registration area when the terminal switches between different systems or networks, reducing signaling loss over the air interface and making interworking between multiple communication systems or networks more convenient and efficient.

[0356] By adopting the above scheme, the terminal requests the core network to establish a context for the terminal under the first RAT and the second RAT through the access network device corresponding to one RAT. In this way, the terminal does not need to register multiple times through access network devices corresponding to multiple RATs. Instead, it only needs to complete the merged registration under multiple RATs with a single registration request, that is, to establish the context of the terminal under multiple RATs in the core network. This reduces the amount of signaling required for the terminal registration process in multi-RAT scenarios, thereby reducing air interface signaling overhead, saving air interface resources, and ultimately improving the terminal's communication efficiency.

[0357] In existing technologies, a single USIM card UE can only maintain one registration state for the same access type (i.e., one RAT type). However, for single-card UEs supporting multiple access points, it is necessary to select two or more PLMN (or NPN) / RAT combinations for registration, which inevitably impacts existing registration management. In general, the existing registration mechanism is primarily designed for UEs to connect to the core network through a single access network device, and is not suitable for situations requiring simultaneous connections to the core network through multiple access network devices. How to manage the registration of multiple legs for multiple access terminals through a single registration request is currently unclear. Furthermore, the establishment of logical NG connections associated with terminals is currently initiated by NG-RAN. For multiple access devices, if only one leg is used to register multiple legs simultaneously, it raises the question of how the AMF initiates the establishment of logical NG connections associated with the UE, and how the AMF determines the access network devices associated with other legs. These issues will be addressed in this example.

[0358] The communication method for merged registration proposed in this application mainly refers to the terminal forwarding a merged registration request to the core network through an access network device, i.e., the access network device corresponding to a RAT, for registering all accesses of multiple access terminals. This application mainly illustrates the example of multiple access terminals registering to the core network through access network devices corresponding to two different RATs. However, in actual processing, this application can also be applied to more RATs. The processing related to other RATs is similar to the processing related to the second RAT, so it will not be described in detail.

[0359] This application provides protection from two perspectives: when the multiple access network devices are managed by the same mobility management network element (AMF), and when the multiple access network devices are managed by different AMF elements. For example, when the 6G MM and 5G MM (AMF) are the same network element or co-located network element, and the UE connects to the same AMF through both 6G and 5G access network devices, the UE can use the same security context on both NAS connections, i.e., use the same encryption key, encryption algorithm, integrity protection key, integrity protection algorithm, and other security parameters, while using different security contexts on both AS connections. In this case, during the merge registration process, the MM needs to find the second access network device and establish a corresponding connection (UE-associated local NG-connection) based on the information about the second access network device provided in the merge registration request message sent by the UE through the first access network device, and configure the necessary overall initial UE context for the second access network device, including PDU session context, security key, mobility restriction list, UE radio capabilities, and UE security capabilities. Correspondingly, if the 5G MM (AMF) and 6G MM are different network elements, the UE connects to the 6G MM through the 6G access network device and connects to the AMF through the 5G access network device. In this case, the UE can use the same or different NAS security contexts on both MMs. In addition, the first MM also needs to find and discover the second MM based on the information provided by the UE in the merge registration request.

[0360] Furthermore, it should be noted that the communication method for merged registration proposed in the above embodiments is not only applicable to terminals with multi-access capabilities registering their multiple access points, but also applicable to general terminal devices interworking between 4G, 5G, and 6G systems, where merged registration registers the UE to the 4G, 5G, and 6G core networks. The main difference between multi-access and interworking lies in whether the UE can simultaneously send and receive data through multiple access network devices.

[0361] Figure 11 is a schematic diagram of the composition structure of a terminal according to an embodiment of this application, including:

[0362] The first communication unit 1101 is used to send a first merged registration request to the first core network device through the access network device corresponding to the first RAT, wherein the first merged registration request is used to request the establishment of a context for the terminal under the first RAT and the second RAT in the core network.

[0363] The first merged registration request carries at least one of the following: the identifier of the terminal, the identifier of the access network device corresponding to the second RAT, the identifier of the cell corresponding to the access network device corresponding to the second RAT, the area information corresponding to the access network device corresponding to the second RAT, the type information of the second RAT, the location information of the terminal, and first indication information, wherein the first indication information is used to indicate that the terminal is registered and managed in multiple RATs.

[0364] The first communication unit is configured to receive a first merge registration acceptance message from the first core network device through the access network device corresponding to the first RAT, wherein the first merge registration acceptance message is used by the terminal to determine that the core network has completed the merge registration of the first RAT and the second RAT.

[0365] The first merged registration acceptance message carries at least one of the following: the identifier of the terminal, the identifier of the second connection, second indication information, one or more registration areas, and one or more NAS identifiers for paging, wherein the second indication information is used to indicate the completion of the establishment of the first connection and the second connection, the first connection is used for transmitting NAS signaling corresponding to the terminal between the access network device corresponding to the first RAT and the core network, and the second connection is used for transmitting NAS signaling corresponding to the terminal between the access network device corresponding to the second RAT and the core network.

[0366] The identifier of the second connection includes at least one of the following: the identifier of the access network device corresponding to the second RAT of the second connection, and the identifier of the core network device corresponding to the second connection.

[0367] The one or more registration areas include at least one of the following: the registration area corresponding to the first RAT, the registration area corresponding to the second RAT, and the registration areas corresponding to the first RAT and the second RAT.

[0368] The one or more NAS identifiers for paging include at least one of the following: a NAS identifier for paging corresponding to a first RAT, a NAS identifier for paging corresponding to a second RAT, or a NAS identifier for paging corresponding to both the first RAT and the second RAT.

[0369] The first merged registration acceptance message also carries at least one of the following: the identifier of the access network device corresponding to the second RAT, the identifier of the cell corresponding to the access network device corresponding to the second RAT, and access layer security parameters between the terminal and the access network device corresponding to the first RAT, wherein the access layer security parameters between the terminal and the access network device corresponding to the first RAT are used to protect the messages transmitted between the terminal and the access network device corresponding to the first RAT.

[0370] The first communication unit is configured to perform at least one of the following: transmit NAS signaling corresponding to the terminal through the access network device corresponding to the first RAT, wherein the access network device corresponding to the first RAT transmits the NAS signaling corresponding to the terminal through the first connection; transmit NAS signaling corresponding to the terminal through the access network device corresponding to the second RAT, wherein the access network device corresponding to the second RAT transmits the NAS signaling corresponding to the terminal through the second connection.

[0371] The first communication unit is configured to receive a first NAS security mode command from the first core network device via the access network device corresponding to the first RAT, wherein the first NAS security mode command is configured to activate a first NAS security context, and the first NAS security context is configured to protect NAS signaling transmitted by the terminal via the access network device corresponding to the first RAT, or the first NAS security context is configured to protect NAS signaling transmitted by the terminal via the access network device corresponding to the first RAT and the access network device corresponding to the second RAT.

[0372] The first communication unit is configured to receive a second NAS security mode command from the second core network device through the access network device corresponding to the second RAT, wherein the second NAS security mode command is used to activate a second NAS security context, and the second NAS security context is used to protect the NAS signaling transmitted by the terminal through the access network device corresponding to the second RAT.

[0373] The first communication unit is configured to perform at least one of the following: negotiate access layer security parameters between the terminal and the access network device corresponding to the first RAT with the access network device corresponding to the first RAT; or negotiate access layer security parameters between the terminal and the access network device corresponding to the second RAT with the access network device corresponding to the second RAT.

[0374] The first communication unit is used to establish an RRC connection with the access network device corresponding to the first RAT, and the terminal establishes an RRC connection with the access network device corresponding to the second RAT.

[0375] The first communication unit is used to establish an RRC connection with the access network device corresponding to the first RAT.

[0376] The first communication unit is used to establish an RRC connection with the access network device corresponding to the second RAT.

[0377] Figure 12 is a schematic diagram of the composition structure of a first core network device according to an embodiment of this application, including:

[0378] The second communication unit 1201 is used to receive a first merged registration request sent by the terminal through the access network device corresponding to the first RAT, wherein the first merged registration request is used to request the establishment of a context for the terminal in the core network under the first RAT and the second RAT.

[0379] The first merged registration request carries at least one of the following: the identifier of the terminal, the identifier of the access network device corresponding to the second RAT, the identifier of the cell corresponding to the access network device corresponding to the second RAT, the area information corresponding to the access network device corresponding to the second RAT, the type information of the second RAT, the location information of the terminal, and first indication information, wherein the first indication information is used to indicate that the terminal is registered and managed in multiple RATs.

[0380] The second communication unit is configured to send a first merge registration acceptance message to the terminal through the access network device corresponding to the first RAT, wherein the first merge registration acceptance message is used by the terminal to determine that the core network has completed the merge registration of the first RAT and the second RAT.

[0381] The first merged registration acceptance message carries at least one of the following: the identifier of the terminal, the identifier of the second connection, second indication information, one or more registration areas, and one or more NAS identifiers for paging, wherein the second indication information is used to indicate the completion of the establishment of the first connection and the second connection, the first connection is used for transmitting NAS signaling corresponding to the terminal between the access network device corresponding to the first RAT and the core network, and the second connection is used for transmitting NAS signaling corresponding to the terminal between the access network device corresponding to the second RAT and the core network.

[0382] The identifier of the second connection includes at least one of the following: the identifier of the access network device corresponding to the second RAT of the second connection, and the identifier of the core network device corresponding to the second connection.

[0383] The one or more registration areas include at least one of the following: the registration area corresponding to the first RAT, the registration area corresponding to the second RAT, and the registration areas corresponding to the first RAT and the second RAT.

[0384] The one or more NAS identifiers for paging include at least one of the following: a NAS identifier for paging corresponding to a first RAT, a NAS identifier for paging corresponding to a second RAT, or a NAS identifier for paging corresponding to both the first RAT and the second RAT.

[0385] The first merged registration acceptance message also carries at least one of the following: the identifier of the access network device corresponding to the second RAT, the identifier of the cell corresponding to the access network device corresponding to the second RAT, and access layer security parameters between the terminal and the access network device corresponding to the first RAT, wherein the access layer security parameters between the terminal and the access network device corresponding to the first RAT are used to protect the messages transmitted between the terminal and the access network device corresponding to the first RAT.

[0386] The second communication unit is configured to send a connection establishment request to the access network device corresponding to the second RAT, wherein the connection establishment request is used by the access network device corresponding to the second RAT to establish the second connection; and to receive a connection establishment response sent by the access network device corresponding to the second RAT, wherein the connection establishment response is used to indicate the completion of the establishment of the second connection.

[0387] The connection establishment request carries at least one of the following: the identifier of the terminal, and the identifier of the core network side corresponding to the second connection.

[0388] The connection establishment request also carries at least one of the following: access layer security parameters between the terminal and the access network device corresponding to the second RAT, wherein the access layer security parameters between the terminal and the access network device corresponding to the second RAT are used to protect messages transmitted between the terminal and the access network device corresponding to the second RAT; and fourth indication information, wherein the fourth indication information is used to indicate that the first core network device accepts the terminal's merged registration or to indicate that the terminal's registration type is merged registration.

[0389] The connection establishment response carries at least one of the following: the identifier of the terminal, the identifier of the access network device side corresponding to the second RAT corresponding to the second connection, and the identifier of the core network side corresponding to the second connection.

[0390] The second communication unit is configured to send a second merge registration request to the second core network device, wherein the second merge registration request is used to request the establishment of a context for the terminal under the second RAT.

[0391] The second merged registration request carries at least one of the following: the identifier of the terminal, the identifier of the access network device corresponding to the second RAT, the identifier of the cell corresponding to the access network device corresponding to the second RAT, the area information corresponding to the access network device corresponding to the second RAT, the type information of the second RAT, the location information of the terminal, and the first indication information.

[0392] The second merged registration request also carries at least one of the following: the NAS identifier for paging corresponding to the first RAT, and the registration area corresponding to the first RAT.

[0393] The second communication unit is configured to receive a second merged registration acceptance message from the second core network device, wherein the second merged registration acceptance message is used by the first core network device to determine that the second core network device has completed registration.

[0394] The second merge registration acceptance message carries at least one of the following: the identifier of the terminal, third indication information indicating that the second core network device supports merge registration, the registration area corresponding to the second RAT, and the NAS identifier for paging corresponding to the second RAT.

[0395] The second merged registration acceptance message carries at least one of the following: third indication information indicating that the second core network device supports merged registration, the registration area corresponding to the first RAT and the second RAT, and the NAS identifier for paging corresponding to the first RAT and the second RAT.

[0396] The second communication unit is used to send a registration message to the UDM, wherein the registration message carries at least one of the following: the identifier of the terminal, the identification information of the first core network device, the fifth indication information, the type information of the first RAT, and information indicating that the associated RAT type is the second RAT, wherein the fifth indication information is used to indicate that the registration type of the terminal is merged registration.

[0397] The second communication unit is configured to send a first NAS security mode command to the terminal via the access network device corresponding to the first RAT, wherein the first NAS security mode command is configured to activate a first NAS security context, and the first NAS security context is configured to protect the NAS signaling transmitted by the terminal via the access network device corresponding to the first RAT, or the first NAS security context is configured to protect the NAS signaling transmitted by the terminal via the access network device corresponding to the first RAT and the access network device corresponding to the second RAT.

[0398] Figure 13 is a schematic diagram of the composition structure of a second core network device according to an embodiment of this application, including:

[0399] The third communication unit 1301 is used to receive a second merge registration request sent by the first core network device, wherein the second merge registration request is used to request the establishment of a context for the terminal under the second RAT.

[0400] The second merged registration request carries at least one of the following: the identifier of the terminal, the identifier of the access network device corresponding to the second RAT, the identifier of the cell corresponding to the access network device corresponding to the second RAT, the area information corresponding to the access network device corresponding to the second RAT, the type information of the second RAT, the location information of the terminal, and first indication information, wherein the first indication information is used to indicate that the terminal is registered and managed in multiple RATs.

[0401] The second merged registration request also carries at least one of the following: the NAS identifier for paging corresponding to the first RAT, and the registration area corresponding to the first RAT.

[0402] The third communication unit is configured to send a connection establishment request to the access network device corresponding to the second RAT, wherein the connection establishment request is used by the access network device corresponding to the second RAT to establish a second connection, and the second connection is used for transmitting NAS signaling corresponding to the terminal between the access network device corresponding to the second RAT and the second core network device; and to receive a connection establishment response sent by the access network device corresponding to the second RAT, wherein the connection establishment response is used to indicate the completion of the establishment of the second connection.

[0403] The connection establishment request carries at least one of the following: the identifier of the terminal, and the identifier of the core network side corresponding to the second connection.

[0404] The connection establishment response carries at least one of the following: the identifier of the terminal, the identifier of the access network device side corresponding to the second RAT corresponding to the second connection, and the identifier of the core network side corresponding to the second connection.

[0405] The third communication unit is used to send a second NAS security mode command to the terminal through the access network device corresponding to the second RAT, wherein the second NAS security mode command is used to activate a second NAS security context, and the second NAS security context is used to protect the NAS signaling transmitted by the terminal through the access network device corresponding to the second RAT.

[0406] The third communication unit is used to send a second merged registration acceptance message to the first core network device, wherein the second merged registration acceptance message is used by the first core network device to determine that the second core network device has completed registration.

[0407] The second merge registration acceptance message carries at least one of the following: the identifier of the terminal, third indication information indicating that the second core network device supports merge registration, the registration area corresponding to the second RAT, and the NAS identifier for paging corresponding to the second RAT.

[0408] The second merged registration acceptance message carries at least one of the following: third indication information indicating that the second core network device supports merged registration, the registration area corresponding to the first RAT and the second RAT, and the NAS identifier for paging corresponding to the first RAT and the second RAT.

[0409] The third communication unit is used to send a registration message to the UDM, wherein the registration message carries at least one of the following: the identifier of the terminal, the identification information of the second core network device, the type information of the second RAT, and a sixth indication information, wherein the sixth indication information is used to indicate that the registration type of the terminal is merged registration.

[0410] The device in this application embodiment can realize the corresponding functions of the various devices in the foregoing communication method embodiments. The processes, functions, implementation methods, and beneficial effects of each module (sub-module, unit, or component, etc.) in this device can be found in the corresponding descriptions in the above method embodiments, and will not be repeated here. It should be noted that the functions described for each module (sub-module, unit, or component, etc.) in the device of this application embodiment can be implemented by different modules (sub-modules, units, or components, etc.) or by the same module (sub-module, unit, or component, etc.).

[0411] Figure 14 is a schematic structural diagram of a communication device 1400 according to an embodiment of this application. The communication device 1400 includes a processor 1410, which can call and run computer programs from a memory to enable the communication device 1400 to implement the methods in the embodiments of this application. In one possible implementation, the communication device 1400 may further include a memory 1420. The processor 1410 can call and run computer programs from the memory 1420 to enable the communication device 1400 to implement the methods in the embodiments of this application. The memory 1420 may be a separate device independent of the processor 1410, or it may be integrated into the processor 1410. In one possible implementation, the communication device 1400 may further include a transceiver 1430, which the processor 1410 can control to communicate with other devices. Specifically, it can send information or data to other devices, or receive information or data sent by other devices. The transceiver 1430 may include a transmitter and a receiver. The transceiver 1430 may further include antennas, and the number of antennas may be one or more.

[0412] In one possible implementation, the communication device 1400 may be a terminal, a first core network device, or a second core network device in the embodiments of this application, and the communication device 1400 may implement the corresponding processes implemented by the terminal, the first core network device, or the first access network device in the various methods of the embodiments of this application. For the sake of brevity, these will not be elaborated here.

[0413] Figure 15 is a schematic structural diagram of a chip 1500 according to an embodiment of this application. The chip 1500 includes a processor 1510, which can call and run computer programs from memory to implement the methods in the embodiments of this application. In one possible implementation, the chip 1500 may further include a memory 1520. The processor 1510 can call and run computer programs from the memory 1520 to implement the methods executed by a terminal, a first core network device, or a second core network device in the embodiments of this application. The memory 1520 may be a separate device independent of the processor 1510, or it may be integrated into the processor 1510. In one possible implementation, the chip 1500 may further include an input interface 1530. The processor 1510 can control the input interface 1530 to communicate with other devices or chips; specifically, it can acquire information or data sent by other devices or chips. In one possible implementation, the chip 1500 may further include an output interface 1540. The processor 1510 can control the output interface 1540 to communicate with other devices or chips, specifically, it can output information or data to other devices or chips.

[0414] In one possible implementation, the chip can be applied to the terminal, the first core network device, or the second core network device in the embodiments of this application, and the chip can implement the corresponding processes implemented by the terminal, the first core network device, or the second core network device in the various methods of the embodiments of this application. For simplicity, these will not be elaborated further here. It should be understood that the chip mentioned in the embodiments of this application can also be called a system-on-a-chip, system-on-a-chip, chip system, or system-on-chip, etc. The processor mentioned above can be a general-purpose processor, a digital signal processor (DSP), a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), or other programmable logic devices, transistor logic devices, discrete hardware components, etc. Among them, the general-purpose processor mentioned above can be a microprocessor or any conventional processor, etc. The memory mentioned above can be volatile memory or non-volatile memory, or can include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM). It should be understood that the above-described memory is exemplary but not limiting. For example, the memory in the embodiments of this application can also be static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct memory bus RAM (DR RAM), etc. In other words, the memory in the embodiments of this application is intended to include, but is not limited to, these and any other suitable types of memory.

[0415] It should be understood that the sequence number of each process in the various embodiments of this application does not imply the order of execution; the execution order of each process should be determined by its function and internal logic. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here. The above descriptions are merely specific embodiments of this application, and the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication method, comprising: The terminal sends a first merged registration request to the first core network device through the access network device corresponding to the first radio access technology (RAT). The first merged registration request is used to request the establishment of a context for the terminal under the first RAT and the second RAT in the core network.

2. The method according to claim 1, wherein, The first merged registration request carries at least one of the following: the identifier of the terminal, the identifier of the access network device corresponding to the second RAT, the identifier of the cell corresponding to the access network device corresponding to the second RAT, the area information corresponding to the access network device corresponding to the second RAT, the type information of the second RAT, the location information of the terminal, and first indication information, wherein the first indication information is used to indicate that the terminal is registered and managed in multiple RATs.

3. The method according to claim 1 or 2, wherein, After the terminal sends the first merge registration request to the first core network device through the access network device corresponding to the first RAT, it also includes: The terminal receives a first merge registration acceptance message from the first core network device through the access network device corresponding to the first RAT, wherein the first merge registration acceptance message is used by the terminal to determine that the core network has completed the merge registration of the first RAT and the second RAT.

4. The method according to claim 3, wherein, The first merged registration acceptance message carries at least one of the following: the identifier of the terminal, the identifier of the second connection, second indication information, one or more registration areas, and one or more NAS identifiers for paging, wherein the second indication information is used to indicate the completion of the establishment of the first connection and the second connection, the first connection is used for transmitting non-access stratum NAS signaling corresponding to the terminal between the access network device corresponding to the first RAT and the core network, and the second connection is used for transmitting NAS signaling corresponding to the terminal between the access network device corresponding to the second RAT and the core network.

5. The method according to claim 4, wherein, The identifier of the second connection includes at least one of the following: the identifier of the access network device corresponding to the second RAT of the second connection, and the identifier of the core network device corresponding to the second connection.

6. The method according to claim 4, wherein, The one or more registration areas include at least one of the following: the registration area corresponding to the first RAT, the registration area corresponding to the second RAT, and the registration areas corresponding to the first RAT and the second RAT.

7. The method according to claim 4, wherein, The one or more NAS identifiers for paging include at least one of the following: a NAS identifier for paging corresponding to a first RAT, a NAS identifier for paging corresponding to a second RAT, or a NAS identifier for paging corresponding to both the first RAT and the second RAT.

8. The method according to any one of claims 4-7, wherein, The first merged registration acceptance message also carries at least one of the following: the identifier of the access network device corresponding to the second RAT, the identifier of the cell corresponding to the access network device corresponding to the second RAT, and access layer security parameters between the terminal and the access network device corresponding to the first RAT, wherein the access layer security parameters between the terminal and the access network device corresponding to the first RAT are used to protect the messages transmitted between the terminal and the access network device corresponding to the first RAT.

9. The method according to any one of claims 4-8, wherein, After the terminal receives the first merged registration acceptance message from the first core network device through the access network device corresponding to the first RAT, it also includes at least one of the following: The terminal transmits the NAS signaling corresponding to the terminal through the access network device corresponding to the first RAT, wherein the access network device corresponding to the first RAT transmits the NAS signaling corresponding to the terminal through the first connection; The terminal transmits the NAS signaling corresponding to the terminal through the access network device corresponding to the second RAT, wherein the access network device corresponding to the second RAT transmits the NAS signaling corresponding to the terminal through the second connection.

10. The method according to any one of claims 3-9, wherein, Before the terminal receives the first merged registration acceptance message from the first core network device through the access network device corresponding to the first RAT, it also includes: The terminal receives a first NAS security mode command from the first core network device through the access network device corresponding to the first RAT. The first NAS security mode command is used to activate a first NAS security context. The first NAS security context is used to protect the NAS signaling transmitted by the terminal through the access network device corresponding to the first RAT, or the first NAS security context is used to protect the NAS signaling transmitted by the terminal through the access network device corresponding to the first RAT and the access network device corresponding to the second RAT.

11. The method according to any one of claims 3-9, wherein, Before the terminal receives the first merged registration acceptance message from the first core network device through the access network device corresponding to the first RAT, it also includes: The terminal receives a second NAS security mode command from the second core network device through the access network device corresponding to the second RAT. The second NAS security mode command is used to activate the second NAS security context, and the second NAS security context is used to protect the NAS signaling transmitted by the terminal through the access network device corresponding to the second RAT.

12. The method according to any one of claims 3-11, wherein, After the terminal receives the first merged registration acceptance message from the first core network device through the access network device corresponding to the first RAT, it also includes at least one of the following: The terminal negotiates the access layer security parameters between the terminal and the access network device corresponding to the first RAT with the first RAT. The terminal negotiates the access layer security parameters between itself and the access network device corresponding to the second RAT.

13. The method according to any one of claims 1-12, wherein, Before the terminal sends the first merge registration request to the first core network device through the access network device corresponding to the first RAT, it also includes: The terminal establishes an RRC connection with the access network device corresponding to the first RAT, and the terminal establishes an RRC connection with the access network device corresponding to the second RAT.

14. The method according to any one of claims 1-12, wherein, Before the terminal sends the first merge registration request to the first core network device through the access network device corresponding to the first RAT, it also includes: The terminal establishes an RRC connection with the access network device corresponding to the first RAT.

15. The method according to claim 14, wherein, After the terminal receives the first merged registration acceptance message from the first core network device through the access network device corresponding to the first RAT, it further includes: The terminal establishes an RRC connection with the access network device corresponding to the second RAT.

16. A communication method, comprising: The first core network device receives a first merged registration request from the terminal through the access network device corresponding to the first RAT, wherein the first merged registration request is used to request the establishment of a context for the terminal in the core network under the first RAT and the second RAT.

17. The method according to claim 16, wherein, The first merged registration request carries at least one of the following: the identifier of the terminal, the identifier of the access network device corresponding to the second RAT, the identifier of the cell corresponding to the access network device corresponding to the second RAT, the area information corresponding to the access network device corresponding to the second RAT, the type information of the second RAT, the location information of the terminal, and first indication information, wherein the first indication information is used to indicate that the terminal is registered and managed in multiple RATs.

18. The method according to claim 16 or 17, wherein, After the first core network device receives the first merge registration request sent by the terminal through the access network device corresponding to the first RAT, it also includes: The first core network device sends a first merge registration acceptance message to the terminal through the access network device corresponding to the first RAT. The first merge registration acceptance message is used by the terminal to determine that the core network has completed the merge registration of the first RAT and the second RAT.

19. The method according to claim 18, wherein, The first merged registration acceptance message carries at least one of the following: the identifier of the terminal, the identifier of the second connection, second indication information, one or more registration areas, and one or more NAS identifiers for paging, wherein the second indication information is used to indicate the completion of the establishment of the first connection and the second connection, the first connection is used for transmitting NAS signaling corresponding to the terminal between the access network device corresponding to the first RAT and the core network, and the second connection is used for transmitting NAS signaling corresponding to the terminal between the access network device corresponding to the second RAT and the core network.

20. The method according to claim 19, wherein, The identifier of the second connection includes at least one of the following: the identifier of the access network device corresponding to the second RAT of the second connection, and the identifier of the core network device corresponding to the second connection.

21. The method according to claim 19, wherein, The one or more registration areas include at least one of the following: the registration area corresponding to the first RAT, the registration area corresponding to the second RAT, and the registration areas corresponding to the first RAT and the second RAT.

22. The method according to claim 19, wherein, The one or more NAS identifiers for paging include at least one of the following: a NAS identifier for paging corresponding to a first RAT, a NAS identifier for paging corresponding to a second RAT, or a NAS identifier for paging corresponding to both the first RAT and the second RAT.

23. The method according to any one of claims 19-22, wherein, The first merged registration acceptance message also carries at least one of the following: the identifier of the access network device corresponding to the second RAT, the identifier of the cell corresponding to the access network device corresponding to the second RAT, and access layer security parameters between the terminal and the access network device corresponding to the first RAT, wherein the access layer security parameters between the terminal and the access network device corresponding to the first RAT are used to protect the messages transmitted between the terminal and the access network device corresponding to the first RAT.

24. The method according to any one of claims 19-23, wherein, Before the first core network device sends the first merged registration acceptance message to the terminal through the access network device corresponding to the first RAT, it also includes: The first core network device sends a connection establishment request to the access network device corresponding to the second RAT, wherein the connection establishment request is used by the access network device corresponding to the second RAT to establish the second connection; The first core network device receives a connection establishment response sent by the access network device corresponding to the second RAT, wherein the connection establishment response is used to indicate the completion of the establishment of the second connection.

25. The method according to claim 24, wherein, The connection establishment request carries at least one of the following: the identifier of the terminal, and the identifier of the core network side corresponding to the second connection.

26. The method of claim 25, wherein, The connection establishment request also carries at least one of the following: The access layer security parameters between the terminal and the access network device corresponding to the second RAT are used to protect the messages transmitted between the terminal and the access network device corresponding to the second RAT. The fourth indication information is used to indicate that the first core network device accepts the merged registration of the terminal, or to indicate that the registration type of the terminal is merged registration.

27. The method according to claim 25 or 26, wherein, The connection establishment response carries at least one of the following: the identifier of the terminal, the identifier of the access network device side corresponding to the second RAT corresponding to the second connection, and the identifier of the core network side corresponding to the second connection.

28. The method according to any one of claims 18-27, wherein, Before the first core network device sends the first merged registration acceptance message to the terminal through the access network device corresponding to the first RAT, it also includes: The first core network device sends a second merge registration request to the second core network device, wherein the second merge registration request is used to request the establishment of a context for the terminal under the second RAT.

29. The method according to claim 28, wherein, The second merged registration request carries at least one of the following: the identifier of the terminal, the identifier of the access network device corresponding to the second RAT, the identifier of the cell corresponding to the access network device corresponding to the second RAT, the area information corresponding to the access network device corresponding to the second RAT, the type information of the second RAT, the location information of the terminal, and the first indication information.

30. The method according to claim 29, wherein, The second merged registration request also carries at least one of the following: the NAS identifier for paging corresponding to the first RAT, and the registration area corresponding to the first RAT.

31. The method according to claim 29 or 30, wherein, After the first core network device sends the second merge registration request to the second core network device, it also includes: The first core network device receives a second merged registration acceptance message from the second core network device, wherein the second merged registration acceptance message is used by the first core network device to determine that the second core network device has completed registration.

32. The method according to claim 31, wherein, The second merge registration acceptance message carries at least one of the following: the identifier of the terminal, third indication information indicating that the second core network device supports merge registration, the registration area corresponding to the second RAT, and the NAS identifier for paging corresponding to the second RAT.

33. The method according to claim 31, wherein, The second merged registration acceptance message carries at least one of the following: third indication information indicating that the second core network device supports merged registration, the registration area corresponding to the first RAT and the second RAT, and the NAS identifier for paging corresponding to the first RAT and the second RAT.

34. The method according to any one of claims 18-33, wherein, After the first core network device sends the first merged registration acceptance message to the terminal through the access network device corresponding to the first RAT, it further includes: The first core network device sends a registration message to the UDM, wherein the registration message carries at least one of the following: the identifier of the terminal, the identification information of the first core network device, the fifth indication information, the type information of the first RAT, and information indicating that the associated RAT type is the second RAT, wherein the fifth indication information is used to indicate that the registration type of the terminal is merged registration.

35. The method according to any one of claims 18-34, wherein, Before the first core network device sends the first merged registration acceptance message to the terminal through the access network device corresponding to the first RAT, it also includes: The first core network device sends a first NAS security mode command to the terminal through the access network device corresponding to the first RAT. The first NAS security mode command is used to activate a first NAS security context. The first NAS security context is used to protect the NAS signaling transmitted by the terminal through the access network device corresponding to the first RAT, or the first NAS security context is used to protect the NAS signaling transmitted by the terminal through the access network device corresponding to the first RAT and the access network device corresponding to the second RAT.

36. A communication method, comprising: The second core network device receives a second merge registration request from the first core network device, wherein the second merge registration request is used to request the establishment of a context for the terminal under the second RAT.

37. The method according to claim 36, wherein, The second merged registration request carries at least one of the following: the identifier of the terminal, the identifier of the access network device corresponding to the second RAT, the identifier of the cell corresponding to the access network device corresponding to the second RAT, the area information corresponding to the access network device corresponding to the second RAT, the type information of the second RAT, the location information of the terminal, and first indication information, wherein the first indication information is used to indicate that the terminal is registered and managed in multiple RATs.

38. The method according to claim 37, wherein, The second merged registration request also carries at least one of the following: the NAS identifier for paging corresponding to the first RAT, and the registration area corresponding to the first RAT.

39. The method according to any one of claims 36-38, wherein, After receiving the second merge registration request from the first core network device, the second core network device also includes: The second core network device sends a connection establishment request to the access network device corresponding to the second RAT. The connection establishment request is used by the access network device corresponding to the second RAT to establish a second connection. The second connection is used to transmit NAS signaling corresponding to the terminal between the access network device corresponding to the second RAT and the second core network device. The second core network device receives a connection establishment response sent by the access network device corresponding to the second RAT, wherein the connection establishment response is used to indicate the completion of the establishment of the second connection.

40. The method according to claim 39, wherein, The connection establishment request carries at least one of the following: the identifier of the terminal, and the identifier of the core network side corresponding to the second connection.

41. The method according to claim 40, wherein, The connection establishment response carries at least one of the following: the identifier of the terminal, the identifier of the access network device side corresponding to the second RAT corresponding to the second connection, and the identifier of the core network side corresponding to the second connection.

42. The method according to any one of claims 39-41, wherein, After receiving the connection establishment response sent by the access network device corresponding to the second RAT, the second core network device further includes: The second core network device sends a second NAS security mode command to the terminal through the access network device corresponding to the second RAT. The second NAS security mode command is used to activate the second NAS security context, which is used to protect the NAS signaling transmitted by the terminal through the access network device corresponding to the second RAT.

43. The method according to claim 42, wherein, After the second core network device sends the second NAS security mode command to the terminal through the access network device corresponding to the second RAT, it also includes: The second core network device sends a second merged registration acceptance message to the first core network device, wherein the second merged registration acceptance message is used by the first core network device to determine that the second core network device has completed registration.

44. The method according to claim 43, wherein, The second merge registration acceptance message carries at least one of the following: the identifier of the terminal, third indication information indicating that the second core network device supports merge registration, the registration area corresponding to the second RAT, and the NAS identifier for paging corresponding to the second RAT.

45. The method according to claim 43, wherein, The second merged registration acceptance message carries at least one of the following: third indication information indicating that the second core network device supports merged registration, the registration area corresponding to the first RAT and the second RAT, and the NAS identifier for paging corresponding to the first RAT and the second RAT.

46. ​​The method according to any one of claims 43-45, wherein, After the second core network device sends the second merge registration acceptance message to the first core network device, it also includes: The second core network device sends a registration message to the UDM, wherein the registration message carries at least one of the following: the identifier of the terminal, the identification information of the second core network device, the type information of the second RAT, and a sixth indication information, wherein the sixth indication information is used to indicate that the registration type of the terminal is merged registration.

47. A terminal, comprising: The first communication unit is configured to send a first merged registration request to the first core network device through the access network device corresponding to the first RAT, wherein the first merged registration request is used to request the establishment of a context for the terminal under the first RAT and the second RAT in the core network.

48. A first core network device, comprising: The second communication unit is used to receive a first merged registration request sent by the terminal through the access network device corresponding to the first RAT, wherein the first merged registration request is used to request the establishment of a context for the terminal in the core network under the first RAT and the second RAT.

49. A second core network device, comprising: The third communication unit is used to receive a second merge registration request sent by the first core network device, wherein the second merge registration request is used to request the establishment of a context for the terminal under the second RAT.

50. A terminal, comprising: A transceiver, a processor, and a memory for storing a computer program, the transceiver for communicating with other devices, and the processor for calling and running the computer program stored in the memory to cause the terminal to perform the method as described in any one of claims 1 to 15.

51. A first core network device, comprising: A transceiver, a processor, and a memory for storing computer programs, the transceiver for communicating with other devices, and the processor for calling and running the computer programs stored in the memory to cause the first core network device to perform the method as described in any one of claims 16 to 35.

52. A second core network device, comprising: A transceiver, a processor, and a memory for storing computer programs, the transceiver for communicating with other devices, and the processor for calling and running the computer programs stored in the memory to cause the second core network device to perform the method as described in any one of claims 36 to 46.

53. A chip, comprising: A processor for retrieving and running a computer program from memory, causing a device having the chip mounted to perform the method as described in any one of claims 1 to 15, or claims 16 to 35, or claims 36 to 46.

54. A computer-readable storage medium for storing a computer program that, when run by a device, causes the device to perform the method as described in any one of claims 1 to 15, or claims 16 to 35, or claims 36 to 46.

55. A computer program product comprising computer program instructions that cause a computer to perform the method as claimed in any one of claims 1 to 15, or claims 16 to 35, or claims 36 to 46.

56. A computer program that causes a computer to perform the method as claimed in any one of claims 1 to 15, or claims 16 to 35, or claims 36 to 46.

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