Abstract: A communication method is provided and includes: A first terminal device sends a first request message to a second terminal device for requesting to obtain a distance and/or an angle between the first terminal device and the second terminal device, the first request message includes first information, and the first information is used by the second terminal device to determine whether to agree to obtain the distance and/or the angle between the first terminal device and the second terminal device; and the first terminal device receives a first response message from the second terminal device, where the first response message includes first indication information indicating a determining result of whether the second terminal device agrees to obtain the distance and/or the angle.

Abstract: This application pertains to the field of communication technologies, and provides a network information processing method and apparatus. In the method, a second network element may support the multi-registration scenario of the terminal through capability enhancement. For example, the second network element may send security information of the terminal to a third network element based on first registration information and second registration information, to support a service between the terminal and an application server.

Abstract: A system, method, and apparatus are provided, which are applied to a scenario where an integrated access and backhaul node migrates from a central unit of a source donor node to a central unit of a target donor node. The method includes: the integrated access and backhaul node and the central unit of the source donor node respectively determine a fifth pre-shared key in their local storage, where the fifth pre-shared key is used to establish a second secure transmission channel between them before the integrated access and backhaul node migrates from the central unit of the source donor node to the central unit of the target donor node, and then the integrated access and backhaul node and the central unit of the source donor node perform security authentication on each other based on the fifth pre-shared key, to establish a first secure transmission channel between them.

Abstract: Embodiments of this application relate to the field of communication technologies, and provide a data transmission method and an apparatus, to ensure security of radio capability information of a terminal in a transmission process. The method includes: A terminal performs NAS security protection on radio capability information based on a NAS security context before establishing an AS security context; then the terminal sends the NAS-security-protected radio capability information to a mobility management network element; and after receiving the NAS-security-protected radio capability information, the mobility management network element performs security deprotection on the NAS-security-protected radio capability information, to obtain and store the radio capability information of the terminal.

Abstract: This application provides a key management method, a device, and a system. The method includes: A terminal device sends a first application session establishment request message to a first application function network element, where the establishment request message carries identification information of a first key, and the first key is an authentication and key management for applications AKMA key. The terminal device receives a first authentication request message in a procedure of the re-authentication. The terminal device sends a response message for the first authentication request message in the procedure of the re-authentication. The terminal device receives a response message for the establishment request message. The terminal device derives a communication key between the terminal device and the first application function network element by using the first key.

Abstract: A configuration data update, where the method includes: When configuration data for a terminal apparatus is first configuration data, where the first configuration data includes a first restriction indication and an empty closed access group (CAG) list, the first restriction indication is used to indicate the terminal apparatus to access a network through a CAG, an access and mobility management function apparatus configures the terminal apparatus to be in a state in which the terminal apparatus is allowed to access the network not only through a CAG in the CAG list. When the configuration data for the terminal apparatus is updated to second configuration data, where a CAG list in the second configuration data is not empty or does not include the first restriction indication, the access and mobility management function apparatus sends the second configuration data to the terminal apparatus.

Abstract: This application provides a communication method and apparatus. The method may include: A terminal device obtains first indication information, where the first indication information indicates at least one multicast key transmission procedure, each multicast key transmission procedure is a communication procedure that is supported by a network side and that is used to transmit a multicast key to the terminal device, and the multicast key is a security transmission key of a multicast session between the terminal device and a first content delivery network element. The terminal device obtains service data from a core network based on a support case of the terminal device for the at least one multicast key transmission procedure.

Abstract: Embodiments of this application provide example communication methods and apparatuses. One example communication method is applied to a communications device, where a subscriber identification module (SIM) card is installed in the communications device, and where the example communication method includes determining, by the communications device, that the SIM card is removed. The communications device can then send alarm information to a network device, where the alarm information indicates that the SIM card in the communications device is removed, and where security protection is performed on the alarm information based on security context stored in the communications device. The communications device can then delete the security context.

Abstract: A communications method includes: an integrated access and backhaul (IAB) node receives an uplink data packet from a terminal; the IAB node determines a packet data convergence protocol (PDCP) layer security status of the uplink data packet; the IAB node determines a target secure tunnel from a plurality of secure tunnels between the IAB node and an IAB donor based on the PDCP layer security status of the uplink data packet; and the IAB node sends the uplink data packet to the IAB donor through the target secure tunnel. This application is applicable to a data transmission process.

Abstract: This application provides a cell handover method and apparatus. The method may include: A terminal device receives a physical layer parameter and system information for a candidate cell, and then measures signal strength of the candidate cell based on the physical layer parameter, and sends a measurement result and signature obtaining indication information and/or signature check result indication information to an access network device, where the signature obtaining indication information indicates whether the system information carries a signature, and the signature check result indication information indicates whether signature check succeeds. In the foregoing solution, the terminal device may indicate, to the access network device, whether the system information for the candidate cell carries the signature and/or whether the signature check of the system information succeeds.

Abstract: Embodiments of this application provide a method and an apparatus for detecting a false base station. The method includes: A network device sends system information to a terminal device, where the system information includes a first signature of the system information and a first timestamp, and the first timestamp identifies time at which the network device generates the first signature. The network device receives private information from the terminal device. The network device signs the private information of the terminal device by using a private key corresponding to the network device, to obtain a second signature. The network sends the second signature to the terminal device. According to the foregoing method, the terminal device can accurately verify whether the terminal device is attacked by a false base station, to improve communication security.

Abstract: Embodiments of this application provide a terminal management method and a core network device. The method includes: A first core network device receives a first message from a terminal. When determining, based on quantity information, to allow the terminal to access the network, the first core network device sends a second message to an operation requester to which the terminal belongs. The quantity information includes a quantity of terminals that the operation requester is allowed to use, the second message includes first identification information. In embodiments of this application, the first core network device determines to allow the terminal to access the network, so that a quantity of terminals accessing the network among terminals corresponding to the operation requester can be prevented from being greater than or equal to the quantity of terminals that the operation requester is allowed to use.

Abstract: Embodiments of this application provide service verification methods, communication apparatuses, and communication systems. In an implementation, a method includes receiving identification information of a service from a terminal device, sending a request to a network element, where the request includes identification information of the terminal device and the identification information of the service, and the request is used to request to verify whether to allow the terminal device to use the service, and receiving a verification result from the network element.

Abstract: A method includes receiving, from a gateway mobile location center, a reliable positioning requirement for obtaining the location of a terminal device. The method also includes determining based on the received reliable position requirement a positioning method that is based on the terminal device reporting and a network-assisted positioning. The method further includes obtaining a first location reported by the terminal device and a second location reported by a base station. The method additionally includes determining location information of the terminal device based on the first location and the second location. The method also includes sending a positioning response to an application function entity from the gateway mobile location center. The positioning response comprises the location information of the terminal device.

Abstract: A data transmission method includes calculating, by a user equipment (UE), a first message authentication code of first location privacy setting data, sending, by the UE, the first message authentication code and the first location privacy setting data to a data management network element, receiving, by the UE, a second message authentication code from the data management network element, calculating, by the UE, a third message authentication code of the first location privacy setting data, determining, by the UE, that the first location privacy setting data is not tampered with when the second message authentication code is the same as the third message authentication code.

Abstract: This application provides a key determining method, and a communication apparatus. The method is applied to a donor node central unit which contains a control plane entity and a user plane entity, and the method includes: deriving a first key based on a root key, an internet protocol (IP) address of a distributed unit of an integrated access and backhaul node, and a first IP address of the user plane entity; and sending a first message to the user plane entity, wherein the first message comprises the first key. According to this application, a user plane secure transmission channel may be established between the user plane entity and the distributed unit based on the first key.

Abstract: The present application discloses methods and apparatuses for tag management. In an example method, a first mobility management function receives a registration request message sent by an access network device. The registration request message requests to register a tag in a core network. The first mobility management function obtains identification information of a second mobility management function from a unified data management function based on the registration request message. The second mobility management function stores context information of the tag. The first mobility management function obtains the context information of the tag from the second mobility management function.

Abstract: Embodiments of a network selection method and a related apparatus are provided. In the method, an apparatus receives a broadcast message from a non-forbidden public land mobile network (PLMN) and a broadcast message from a forbidden PLMN. The broadcast message of the forbidden PLMN includes a disaster occurrence indication, and the disaster occurrence indication indicates that a disaster has occurred on the non-forbidden PLMN. The apparatus requests, based on the disaster occurrence indication, to register with the forbidden PLMN, when the apparatus fails to register with the non-forbidden PLMN. According to the foregoing method, the apparatus can select a network that ensures a normal service, and a service interruption to the apparatus caused by the disaster that occurs on the non-forbidden PLMN can be effectively reduced.

Abstract: This application provides a communication method, apparatus, and system. The method includes: A first node communicates with a first donor node by using a first key, where the first key includes a key used for communication over an air interface and/or a key 1 used for communication over an F1 interface. After the first node receives first information from the first donor node, the first node maintains the first key and a second key in response to the first information, where the second key includes a key used for communication over an air interface between the first node and a second donor node and/or a key 2 used for communication over the F1 interface.

Abstract: This application provides a method for controlling a connection between a terminal and a network, and an apparatus. The method includes: receiving, by a terminal, a packet filter; and discarding, by the terminal, an uplink data packet matching the packet filter. Based on this solution, a connection can be blocked near a source (that is, the connection is blocked from the terminal), to reduce traffic exchanged between the terminal and a user plane network element. Compared with an existing technical solution, the terminal implements traffic control to reduce a quantity of uplink data packets sent to the user plane network element, thereby reducing load of the user plane network element.