Abstract: A communication method, a communications device, and a communications system to avoid, when an access and mobility management function (AMF) entity fails, a case in which a re-registration process of a terminal that is being served is triggered because a context of the terminal is lost. The method includes: obtaining, by a communications device, a first group identifier of a terminal group to which a first terminal served by a first mobility management entity belongs; and sending, by the communications device, a message related to the first terminal to a second mobility management entity based on the first group identifier when an exception occurs in the first mobility management entity, where the second mobility management entity is a mobility management entity in which a context of the first terminal exists.

Abstract: An access control method includes: receiving, by a network device, an access request message from user equipment (UE); determining, by the network device based on the access request message, a network slice that the UE requests to access; and when the network device determines to reject an access request of the UE for accessing the network slice, returning, by the network device, a rejection response message to the UE, where the rejection response message includes back-off condition information, and the back-off condition information indicates a condition under which the UE requests again to access the network slice.

Abstract: A communication method applicable to different scenarios of interworking between communications systems includes determining, by a session management network element, a first data channel in a first system, where the first data channel is a data channel to be synchronized with a terminal device; and synchronizing, by the session management network element in an interworking procedure for the terminal device from the first system to a second system, at least one of the first data channel or a second data channel that is in the second system and that corresponds to the first data channel.

Abstract: A method includes: receiving first information, where the first information indicates a data network to which a first anchor UPF network element managed by the second SMF network element is connected; determining based on the first information, first rule information to be executed by a first network element managed by the second SMF network element, where the first network element includes at least one of the first anchor UPF network element or a branching point, the branching point is a UPF network element having a traffic offload function, the branching point is connected to the first anchor UPF network element, the first rule information indicates a processing method to be performed on a data packet of a first application, and the data packet of the first application is transmitted through the first anchor UPF network element; and sending second information, where the second information includes the first rule information.

Abstract: A communication method and a communications device, where the communication method includes: receiving a first message sent by a first service instance, where the first message includes a target identifier; and sending, based on the first message, a second message to a second service instance that has a binding relationship with the target identifier.

Abstract: A communication method, a communications device, and a communications system to avoid, when an access and mobility management function (AMF) entity fails, a case in which a re-registration process of a terminal that is being served is triggered because a context of the terminal is lost. The method includes: obtaining, by a communications device, a first group identifier of a terminal group to which a first terminal served by a first mobility management entity belongs; and sending, by the communications device, a message related to the first terminal to a second mobility management entity based on the first group identifier when an exception occurs in the first mobility management entity, where the second mobility management entity is a mobility management entity in which a context of the first terminal exists.

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: 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 Packet Data Network (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: The present application discloses a DCN processing method for a PLMN that is applied to a network sharing scenario. An access feedback message of a network side is received, and selection assistance information of a DCN and an identifier of a PLMN that serves UE are obtained from the access feedback message, so as to know a PLMN that is actually accessed by the UE. A correspondence between the selection assistance information of the DCN and the identifier of the PLMN that serves the UE is stored. When the UE moves to coverage of the PLMN, a requested DCN to be accessed can be directly determined according to the correspondence, and a RAN node is requested to access the determined DCN. Therefore, a redirection process is reduced, and resource overheads are reduced.

Abstract: A communication method applicable to different scenarios of interworking between communications systems includes determining, by a session management network element, a first data channel in a first system, where the first data channel is a data channel to be synchronized with a terminal device; and synchronizing, by the session management network element in an interworking procedure for the terminal device from the first system to a second system, at least one of the first data channel or a second data channel that is in the second system and that corresponds to the first data channel.

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/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 core network device selection method and apparatus are disclosed. The method includes: receiving, by an access network node, an access stratum message sent by a terminal, where the access stratum message includes a NAS request message and a network selection auxiliary parameter; querying configuration information based on the network selection auxiliary parameter, and determining a group identifier of at least one mobility management device group, where the configuration information includes a correspondence between a network selection auxiliary parameter and a group identifier of a mobility management device group; determining a device identifier of a target mobility management device based on the group identifier of the at least one mobility management device group; and sending the NAS request message to a mobility management device indicated by the device identifier of the target mobility management device.

Abstract: Embodiments of the present invention disclose a method, a network element, and a system for determining a target RAT. The method includes: receiving, by an access network element, access control information of a UE that is sent by a mobility management network element, where the access control information includes an identity of a PLMN and a radio access technology RAT allowed and/or a RAT not allowed by the PLMN; and determining, by the access network element, a target RAT for the UE according to the access control information.

Abstract: A method for establishing a local network connection, where the method includes: obtaining, by a terminal, broadcast information sent by a base station; if the broadcast information includes a first local data network (LDN) list, determining a target local network identifier based on the first LDN list, where the first LDN list includes at least one local network identifier; and establishing, by the terminal, a session connection using the target local network identifier.

Abstract: A binding support method, including: receive 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; receive 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 determine the target policy control network element based on the third information and the first request message.

Abstract: A message transmission method includes receiving, by a first transmission proxy, a first message from a first service instance, where the first message includes an identifier of a first service set, obtaining, by the first transmission proxy, a second service instance in the first service set based on the identifier that is of the first service set and that is included in the received first message, and sending, by the first transmission proxy, a second message to the second service instance based on the first message.

Abstract: A communication method and a communications device, where the communication method includes: receiving a first message sent by a first service instance, where the first message includes a target identifier; and sending, based on the first message, a second message to a second service instance that has a binding relationship with the target identifier.

Abstract: Embodiments of the present disclosure provide a method, a RAN node, and UE for selecting a service network, and a management device. The method includes: determining a service requirement list of the UE, where the service requirement list includes at least one service required by the UE; determining a service capability list set including a service capability list of at least one service network, where the service capability list includes an identifier of a service network corresponding to the service capability list and includes at least one service supported by the service network; and determining, according to the service requirement list and the service capability list set, a first identifier of a first service network that provides a service for the UE, where a service capability list of the first service network includes all or part of the at least one service in the service requirement list present disclosure.

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: 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.