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 user plane security enforcement information determining method and an apparatus are provided, to ensure a security requirement of transmitted data of a remote device. In this application, a session management network element may receive a first request for creating a relay-type session of a first terminal device. Then, the session management network element determines first user plane security enforcement information of the session based on first information, and sends the first user plane security enforcement information of the session to an access network device, where the first user plane security enforcement information of the session is for determining a first user plane security activation status of the session between the first terminal device and the access network device.

Abstract: A communications method includes determining a session management function entity based on at least one of a data network name, slice information, and an application function service identifier, and sending a first message to the session management function entity, where the first message is used to subscribe to a terminal event, the first message includes service description information, and the service description information is used to indicate a service corresponding to the terminal event.

Abstract: A visible-light-photocatalyzed composite light-transmitting concrete contains several bundles of optical fibers, the optical fibers are coated with a protective layer on their outer surface, the protective layer contains a visible light photocatalyst, and the concrete has several gas-permeable pores. Such concrete is prepared by mixing a visible light photocatalyst and a light-transmitting glue, applying the mixture to the surface of optical fibers to form a protective layer, and using optical fibers in the concrete. The resulting concrete has dual properties of light transmittance and photocatalytic oxidation of gas-phase pollutants under visible light irradiation. The visible-light-photocatalyzed composite light-transmitting concrete significantly breaks through the limitation of photocatalytic concrete to light sources, so that gas-phase pollutants can be removed under visible light irradiation through photocatalysis of light-transmitting concrete.

Abstract: An address obtaining method includes obtaining, by a third network device, an identifier of a first application from a terminal device. The identifier of the first application indicates a request for obtaining an address of an instance of the first application. The address obtaining method further includes sending, by the third network device, a first message to a first network device, wherein the first message comprises the identifier of the first application, and the first message is useable to request the address of the instance of the first application. The address obtaining method further includes receiving, by the third network device, the address of the instance of the first application from the first network device, and sending the address of the instance of the first application to the terminal device.

Abstract: This application provides a QoS flow control method and an apparatus. An SMF network element receives first indication information sent by an access network apparatus, where the first indication information is used to indicate that a first QoS target of a QoS flow cannot be met; and the SMF network element does not process the QoS flow if the SMF network element receives second indication information in a first preset time; or the SMF network element deletes or modifies the QoS flow if the SMF network element does not receive second indication information in a first preset time, where the second indication information is used to indicate that the first QoS target can be met.

Abstract: This application provides a communication system, method, and apparatus, to resolve a prior-art problem that a terminal device does not know how to initiate a correct procedure to establish a communication connection to an application function AF to obtain a business service. A principle of the method is as follows: An AF sends a service mode supported by the AF to UE by using a core network. Therefore, before initiating a service to the AF, the UE can sense the service mode supported by the AF, and the UE initiates a correct connection establishment procedure to the AF based on the service mode supported by the AF.

Abstract: A method for obtaining an identifier of a terminal device includes a key management network element receiving, from a first terminal device, a first key request including a first identifier, where the first identifier is an anonymous identifier or a temporary identifier of a second terminal device. The key management network element sends, to a unified data management network element, a first request including the first identifier. The unified data management network element determines a SUPI of the second terminal device based on the first identifier, and sends, to the key management network element, a first response including the SUPI. In response to an authorization check performed on the second terminal device based on the SUPI succeeds, the key management network element sends a first key response to the first terminal device, where the first key response includes a secure communication parameter.

Abstract: A multicast communication method and a communication apparatus provide for transmission of data of a multicast service using a PDU session established by a terminal device to improve network element utilization. An AF network element sends first multicast service indication information to a session management network element indicating a first multicast service. The session management network element sends, based on the first multicast service indication information, multicast service information to an access network device that serves a terminal device. The access network device establishes an association relationship between the terminal device and the first multicast service based on the multicast service information, so that the access network device can send, when receiving data of the first multicast service, the data of the first multicast service to the terminal device using a PDU session.

Abstract: This application provides a communication system, method, and apparatus. The system is applied to implement AKMA service-based data transmission between a terminal device and an application function network element, and the system includes an AKMA anchor function network element and a network exposure function network element. The network exposure function network element obtains first identification information from a unified data management network element, where the first identification information is used to determine an authentication server function network element corresponding to the terminal device, and sends the first identification information to the AKMA anchor function network element. The AKMA anchor function network element obtains, from the unified data management network element based on the first identification information, identification information of the authentication server function network element corresponding to the terminal device.

Abstract: Example communication methods and apparatus are described. One example communication method includes receiving first indication information by a first network element from a second network element, where the first indication information is used to indicate that a current condition supports establishment of a session of a first network for a terminal apparatus. The first network element obtains first quality of service (QoS) control information of a first session of the terminal apparatus after receiving the first indication information, where the first session is a session established by the terminal apparatus by using a second network. The first network element sends the first QoS control information to the second network element.

Abstract: A communication method includes receiving, by an access network (AN) node, indication information from a mobility management device. The indication information is indicative of a security policy of a quality of service (QoS) flow. The method also includes obtaining, by the access network node based on the indication information, security information of a radio bearer corresponding to the QoS flow. The security information is indicative of a security policy of the radio bearer. The method further includes sending, by the access network node, an identifier of the radio bearer and the security information of the radio bearer to a terminal.

Abstract: A communications method includes determining a session management function entity based on at least one of a data network name, slice information, and an application function service identifier, and sending a first message to the session management function entity, where the first message is used to subscribe to a terminal event, the first message includes service description information, and the service description information is used to indicate a service corresponding to the terminal event.

Abstract: This application provides a method and an apparatus for invoking an application programming interface (API), to determine a target exposing function network element used to invoke an API. The method includes: A first network element obtains routing information of an API, where the routing information is used to indicate a route for invoking the API, and the API is provided by a first exposing function network element and a second exposing function network element; the first network element obtains invocation parameter information of the API, where the invocation parameter information is used to handle the API; and the first network element determines a target exposing function network element in the first exposing function network element and the second exposing function network element based on the routing information and the invocation parameter information.

Abstract: A first network device receives a group selection request, where the group selection request is used to instruct to set a first MCPTT group as a selected MCPTT group for a first MCPTT user; and the first network device sends, according to the group selection request, information about the first MCPTT group to first UE used by the first MCPTT user, so that the first network device can set the first MCPTT group as a selected MCPTT group for the first MCPTT user.

Abstract: Embodiments of the present application relate to the wireless communications field, and in particular, to a session management method and a session management network element. The session management method includes: receiving, by a first control plane network element, a user equipment UE context response message from a second control plane network element, where the UE context response message carries a first session message, and the first session message is a pending session message; and sending, by the first control plane network element, a second session message to user equipment according to the UE context response message. According to the session management method and the session management network element in the embodiments of the present application, a session can be managed in a scenario in which a control plane connection of user equipment changes.

Abstract: A visible-light-photocatalyzed composite light-transmitting concrete contains several bundles of optical fibers, the optical fibers are coated with a protective layer on their outer surface, the protective layer contains a visible light photocatalyst, and the concrete has several gas-permeable pores. Such concrete is prepared by mixing a visible light photocatalyst and a light-transmitting glue, applying the mixture to the surface of optical fibers to form a protective layer, and using optical fibers in the concrete. The resulting concrete has dual properties of light transmittance and photocatalytic oxidation of gas-phase pollutants under visible light irradiation. The visible-light-photocatalyzed composite light-transmitting concrete significantly breaks through the limitation of photocatalytic concrete to light sources, so that gas-phase pollutants can be removed under visible light irradiation through photocatalysis of light-transmitting concrete.

Abstract: This application discloses a multicast session establishment method and a network device, and relates to the field of wireless communication technologies, to implement establishment of a multicast session based on a network architecture that has been deployed by an operator. In one example, when the multicast session is established, policy control, for example, quality of service QoS control, of the multicast session may be completed via a policy control network element or a session management network element in the network architecture that has been deployed by the operator.

Abstract: A communication method includes receiving, by a policy control network element executed by a processor, first information. The first information is service information or a traffic steering requirement. The traffic steering requirement includes at least one service function. The communication method also includes obtaining, by the policy control network element, first traffic steering policy information from a first network element based on the first information. The first traffic steering policy information indicates network elements corresponding to the at least one service function and a sequence in which service data passes through the network elements corresponding to the at least one service function.

Abstract: Disclosed is an AMBR control method, device, and system, so that a quality of service (QoS) control mechanism can be used to control use of resources in a network slice by a terminal device. The method includes: a mobility management network element obtaining M pieces of single network slice selection assistance information (S-NSSAI) corresponding to a terminal device and a first slice-AMBR corresponding to each piece of S-NSSAI in the M pieces of S-NSSAI; and sending the M pieces of S-NSSAI and the first slice-AMBR corresponding to each piece of S-NSSAI to an access network device, where the first slice-AMBR corresponding to each piece of S-NSSAI is used to determine a second slice-AMBR corresponding to the S-NSSAI, and the second slice-AMBR corresponding to each piece of S-NSSAI is used to control an aggregate bit rate of non-guaranteed bit rate non-GBR QoS flows in a network slice indicated by the S-NSSAI.