Abstract: Embodiments of the present disclosure disclose a mobility management method, apparatus, and system, and pertain to the field of wireless communications technologies. The method includes: determining, by a first mobility management entity based on information about a PDN connection established by user equipment in a 4G network, a network slice corresponding to the PDN connection, and then determining, with reference to a subscribed network slice of the user equipment, a network slice allowed for the user equipment.

Abstract: This application discloses a load relocation method, apparatus, and a system. The method includes determining, by a communications network entity, a target access management entity for load relocation; and sending, to an access network entity, an identifier of an original access management entity and an identifier of the target access management entity or an address of the target access management entity with respect to the access network entity. The access network entity sends a message from a user equipment (UE) to the target access management entity based on the identifier of the original access management entity carried in the message from the UE. In the foregoing solution, signaling overheads in a load relocation process are reduced and load relocation efficiency is improved.

Abstract: Methods and apparatuses for acquisition of an Address Resolution Protocol (ARP)/IPv6 neighbour cache at a user plane function (UPF) entity without performing deep packet inspection for every packet that traverses a network. The ARP broadcast/Internet Control Message Protocol version 6 (ICMPv6) neighbour solicitation multicast from any Ethernet client (a user equipment (UE) or clients behind the UE or clients in a data network (DN)) is responded to by the UPF entity itself, by looking up the ARP/IPv6 Neighbour cache built in the UPF entity, irrespective of whether the UPF entity acts as the core Ethernet switch or whether the core Ethernet switch is in the DN. The solution is simplified to always intercept ARP at the UPF entity and respond to it based on a local ARP/IPv6 Neighbour cache.

Abstract: A network access method includes a first terminal that sends a first message to an access management network element in a first non-public network, where the first message is used to request to register the first terminal with the first non-public network. The first terminal receives a second message from the access management network element, where the second message is used to indicate that registration of the first terminal with the first non-public network is rejected, the second message includes first indication information, and the first indication information indicates that access of the first terminal to the first non-public network is forbidden. The first terminal adds information about the first non-public network to a forbidden network list of the first terminal based on the first indication information.

Abstract: A communication method includes a first network element receiving identity information of a terminal from a second network element, where the identity information includes an identity of the terminal or an identity of a group of the terminal; the first network element obtaining, based on the identity information, type information of a serving network corresponding to the identity information; and the first network element sending API information of the first network element based on the type information. Based on this communication method, the second network element can select an available API based on the API information or the type information of the serving network and invoke the available API.

Abstract: The technology of this application relates to a data transmission method. The method includes an application server sending a subscription request to a core network element, to subscribe to a notification indicating whether transmitting data of a first service to first user equipment in a multicast mode is supported, so that a transmission mode of the data of the first service can be flexibly selected based on a subscription result.

Abstract: Embodiments of the present invention relate to the communications field, and provide a method for determining a control plane node, an apparatus, and a wireless communications system, so as to select, for UE, a control plane node corresponding to a network slice to which the UE belongs, thereby ensuring that the control plane node can provide a customized service for the UE. The method includes: obtaining, by UE, indication information, where the indication information is used to indicate a network slice to which the UE belongs; and sending, by the UE, an access layer request message to a radio access network node, where the access layer request message includes the indication information, and the access layer request message is used to trigger the radio access network node to determine, based on the indication information, a control plane node corresponding to the network slice for the UE.

Abstract: Embodiments of this application provide a rate adjustment method, an apparatus, and a system. The method may include the following steps: A mobility management network element determines access information indicating whether a terminal uses NR for access, and determines first APN-AMBR information based on the access information, where the first APN-AMBR information is used to control a data transmission rate.

Abstract: A binding support method, includes receiving third information from the source policy control network element, wherein the third information comprises session information of a policy session and an identifier of a policy control network element set to which the source policy control network element belongs, receiving a first request message from an application network element to query a target policy control network element that serves the policy session, the first request message comprises the session information of the policy session, the session information of the policy session is used to indicate the policy session, and determining the target policy control network element based on the third information and the first request message.

Abstract: Embodiments of this application provide a radio bearer configuration method, an apparatus, and a system. A multicast radio bearer used to receive a multicast/broadcast service is established between a terminal and a base station, to reduce complexity of processing the data of the multicast service by the base station. This solution includes: A base station receives a first request message, where the first request message requests to add a first terminal to a multicast/broadcast service; and the base station sends configuration information of a multicast radio bearer to the first terminal based on quality of service QoS flow information of the multicast/broadcast service. The configuration information is used to configure the multicast radio bearer, the multicast radio bearer is used to transmit data of the multicast/broadcast service to a terminal that has joined the multicast/broadcast service, and the terminal that has joined the multicast/broadcast service includes the first terminal.

Abstract: A communication method and apparatus are provided. In the method, an SMF sends first information to a first user plane network element, where the first information indicates the first user plane network element to send a report message to the SMF when receiving a first DNS response message that meets a first condition, and the report message includes information about an application server indicated by the first DNS response message or information about a data network corresponding to the application server. The first user plane network element sends the report message to the SMF when determining that the received first DNS response message meets the first condition. The SMF inserts the local session anchor based on the report message.

Abstract: An address management method, system, and device to avoid a problem that a same Internet Protocol (IP) address is assigned to different packet data unit (PDU) sessions and to effectively use IP addresses in an address pool. The method includes: obtaining, by a session management network element, an identifier of a user plane function network element serving a terminal and session information of the terminal; determining, by the session management network element based on the identifier of the user plane function network element and the session information, an address pool identifier corresponding to the session; sending, by the session management network element, the address pool identifier to a server, where the address pool identifier is used to assign an IP address to the session; and receiving, by the session management network element from the server, the IP address corresponding to the session.

Abstract: This application discloses a load relocation method, apparatus, and a system. The method includes determining, by a communications network entity, a target access management entity for load relocation; and sending, to an access network entity, an identifier of an original access management entity and an identifier of the target access management entity or an address of the target access management entity with respect to the access network entity. The access network entity sends a message from UE to the target access management entity based on the identifier of the original access management entity carried in the message from the UE. In the foregoing solution, signaling overheads in a load relocation process are reduced and load relocation efficiency is improved.

Abstract: This application provides a communication method and a communications apparatus, to help control switching of a PDU session, thereby improving system performance. The method includes: determining, by a network device based on switching indication information of protocol data unit PDU sessions established by a terminal in a first network, a target PDU session from the established PDU sessions, where all the established PDU sessions have a same data network name DNN; and sending, by the network device, session information of the target PDU session to a mobility management entity device in a second network.

Abstract: A session establishment method and an apparatus, such that an established packet data network (PDN) connection is transferred to a network slice in a fifth generation (5G) network during inter-system mobility of a terminal. The method includes receiving, by a terminal from a control plane function entity, corresponding network slice information used for transferring an established PDN connection to a 5G network, where the corresponding network slice information includes corresponding single network slice selection assistance information (S-NSSAI). The method further includes sending a packet data unit (PDU) session establishment request, where the PDU session establishment request includes corresponding S-NSSAI used for transferring a first PDN connection to the 5G network and a corresponding data network name (DNN) used for transferring the first PDN connection to the 5G network, and the first PDN connection is any one of one or more established PDN connections.

Abstract: A communication method, a communications apparatus, and a communications system, where the method includes: a first network element receiving identity information of a terminal from a second network element, where the identity information includes an identity of the terminal or an identity of a group of the terminal; the first network element obtaining, based on the identity information, type information of a serving network corresponding to the identity information; and the first network element sending API information of the first network element based on the type information. Based on this method, the second network element can select an available API based on the API information or the type information of the serving network and invoke the available API.

Abstract: A communication method and a communications apparatus, wherein the communication method includes: receiving, by a network repository network element, a first request message from a mobility management network element, where the first request message carries a data network name of a session that a terminal device requests to establish; determining, by the network repository network element based on the first request message, at least one target session management network element from session management network elements that support the data network name; and sending, by the network repository network element, an identifier of the at least one target session management network element to the mobility management network element, such that a session management network element can be selected to provide a service for a terminal device.

Abstract: A redirection method, a communications system, and a communications apparatus, to implement redirection of a terminal between different systems, and further implement redirection between a 5th generation system (5GS) and an evolved packet system (EPS). The method includes: a mobility management network element in a first system determining, based on a cellular Internet of things (CIOT) feature supported by a terminal in a second system and a CIOT feature preferred by the terminal in the second system, to redirect the terminal to the second system; and the mobility management network element in the first system sending redirection indication information to the terminal, where the redirection indication information indicates the terminal to redirect to the second system.

Abstract: A method and an apparatus for determining a protocol data unit (PDU) session service network element to control an aggregated maximum bit rate (AMBR), where the method includes receiving, by a control plane function network element, a request for establishing a first PDU session from a mobility management device, where the request for establishing the first PDU session includes a first data network name (DNN), determining, by the control plane function network element, that a same control plane function network element and a same user plane function network element need to be selected for a PDU session corresponding to the first DNN, and sending, by the control plane function network element, first indication information to the mobility management device, where the first indication information is used to indicate that a same control plane function network element needs to be selected for the PDU session corresponding to the first DNN.

Abstract: A service implementation method, apparatus, and system are disclosed. The service implementation method includes: receiving, by a serving gateway, a data packet of a terminal device sent by a packet data network gateway; if the data packet is a data packet with a serving priority and the serving gateway has sent a paging trigger message with a serving priority to a mobility management element, skipping, by the serving gateway, sending a paging trigger message to the mobility management element; or if the data packet is a data packet with a serving priority and the serving gateway has sent no paging trigger message with a serving priority to a mobility management element, sending, by the serving gateway, a paging trigger message to the mobility management element; wherein the paging trigger message is used to enable the mobility management element to page the terminal device.