Abstract: This application discloses a communications method and apparatus. The method includes: sending, by a session management network element, first indication information when the session management network element determines, based on first information, to establish a first low-latency service flow for a session; and the first indication information is used to indicate to set the session to an always-on session. According to solutions of this application, when determining, based on the local configuration information, the subscription data, and the QoS parameter, to establish the low-latency service flow, the session management network element flexibly indicates a terminal apparatus to set the session to the always-on session. This avoids a resource waste caused by setting the session to the always-on session all the time, and avoids a transmission latency caused when the session is not set to the always-on session in time, so that resource utilization and transmission efficiency are improved.

Abstract: Embodiments of the present disclosure relate to a policy control method and system, a network element, and a storage medium. A control plane network element establishes, for UE, a first DN connection that uses a first forwarding plane network element as an anchor. The method includes: when the control plane network element receives a handover notification message for the UE and determines that a second forwarding plane network element serves the UE, or when the control plane network element establishes, for the UE, a second DN connection that uses a second forwarding plane network element as an anchor, the control plane network element updates a forwarding path of the first DN connection, so that an updated forwarding path of the first DN connection passes through the second forwarding plane network element, and the second forwarding plane network element performs policy control on a packet on the first DN connection.

Abstract: Embodiments of this application relate to the field of communication technologies, and in particular, to a roaming data processing method and apparatus, and a system. The method is used to effectively collect data of a terminal in a roaming scenario. The method includes a first data analytics network element receiving, from a visited first network element, data of a terminal on the first network element, where the data includes first information and a first identifier, the first information is used to indicate that the terminal is roaming, and the first information includes any one or more of the following information corresponding to the terminal: a home PLMN identifier, a visited PLMN identifier, home area information, and visited area information.

Abstract: A data processing method includes obtaining, by a session management function (SMF) network element from an external network element, a media access control (MAC) address of a terminal device and an Internet Protocol (IP) address corresponding to the MAC address, and sending, by the SMF network element, the MAC address and the IP address to a first user plane function (UPF) network element, where the MAC address and the IP address are used to send an Address Resolution Protocol (ARP) message, and the ARP message includes the MAC address and the IP address.

Abstract: A paging method and apparatus are provided to simplify a prior-art paging process. The method includes: receiving, by an access device, downlink data, where the downlink data includes a first identifier of a terminal; determining a paging identifier based on the first identifier; and sending, by the access device, a paging message to the terminal, where the paging message carries the paging identifier. After the access device receives the downlink data, the access device can initiate the paging process without using a control plane network element device. The advantages of the innovative paging methods disclosed herein include reduced signaling, shortened signaling transmission, and simplified paging process.

Abstract: A method includes obtaining, by a data analytics device, data of a terminal on an access device and data of the terminal on an access and mobility management function device, where the data of the terminal on the access device includes a first identifier, and the access device is an access device, the data of the terminal on the access and mobility management function device includes the first identifier, and the first identifier includes an identifier assigned by the access device to the terminal, associating, by the data analytics device, the data of the terminal on the access device with the data of the terminal on the access and mobility management function device based on the first identifier.

Abstract: Various embodiments provide a packet transmission method and an apparatus. In those embodiments, a first device supports a first protocol layer, and replicates a packet at the first protocol layer. A second device supports a second protocol layer, and deduplicates the packet at the second protocol layer. When receiving a first packet, a first access device converts a sequence number of the first protocol layer in the first packet into a sequence number of the second protocol layer, and then sends, to the second device, a second packet that carries the sequence number of the second protocol layer and a data packet of the first packet. For example, if the first access network device receives two packets having same data packets, the first access network device separately coverts sequence numbers in the two packets without performing operations of first deduplicating and then replicating the packet.

Abstract: This application relates to the field of wireless communications technologies, and provides a method for selecting a radio access network device. The method includes: obtaining, by a first RAN device, capability information of a second RAN device, where the capability information is used to indicate an LADN supported by the second RAN device; and sending, by the first RAN device, a handover request message to the second RAN device.

Abstract: A method includes obtaining, by a data analytics network element, data of a terminal on an access network element and data of the terminal on an access and mobility management function network element, where the data of the terminal on the access network element includes a first identifier, and the access network element is an access network element, the data of the terminal on the access and mobility management function network element includes the first identifier, and the first identifier includes an identifier assigned by the access network element to the terminal, associating, by the data analytics network element, the data of the terminal on the access network element with the data of the terminal on the access and mobility management function network element based on the first identifier.

Abstract: A session management method and a session management function network element are provided. The session management method includes: learning, by a session management function SMF network element, of whether a first condition is met, where the first condition includes: a first location of user equipment UE is outside a service area SA of a local area data network LADN; and in response to determining that the first condition is met, stopping, by the SMF network element, data transmission of an LADN packet data unit PDU session of the LADN, and maintaining, by the SMF network element, a resource of the LADN PDU session.

Abstract: This application provides a synchronization method and an apparatus, to implement synchronization with a TSN clock in a mobile network. The synchronization method is performed by a first network element in a relay network. The relay network includes a radio access network RAN device and a terminal device. The method includes: The first network element receives a clock synchronization packet. The first network element determines first duration of the relay network, where the first duration of the relay network includes a first downlink transmission delay of transmitting the clock synchronization packet between the RAN device and the terminal device. The first network element determines a time correction field of the relay network, where the time correction field includes the first downlink transmission delay.

Abstract: This application provides a method for controlling disorder of downlink data and an apparatus thereof. The method includes: A control plane network element determines to switch from a first user plane device to a second user plane device, and sends indication information to the second user plane device. The second user plane device buffers, according to the received indication information, downlink data received from a session anchor, and sends the buffered downlink data after reception of an end marker from the first user plane device.

Abstract: A paging method and apparatus are provided to simplify a prior-art paging process. The method includes: receiving, by an access device, downlink data, where the downlink data includes a first identifier of a terminal; determining a paging identifier based on the first identifier; and sending, by the access device, a paging message to the terminal, where the paging message carries the paging identifier. After the access device receives the downlink data, the access device can initiate the paging process without using a control plane network element device. The advantages of the innovative paging methods disclosed herein include reduced signaling, shortened signaling transmission, and simplified paging process.

Abstract: Methods, systems, and apparatus for clock synchronization are provided. In one aspect, a clock synchronization method includes: receiving, by a terminal and from an access network device, information about N clock domains, determining, by the terminal, M clock domains that are associated with the terminal and that are in the N clock domains, and separately performing, by the terminal, clock synchronization with clock sources of the M clock domains based on information about the M clock domains. Information about a clock domain includes first time information and a clock domain number of the clock domain. The first time information includes a time of a clock source of the clock domain when the access network device sends the information about the clock domain. The clock domain number identifies the clock domain. N is an integer greater than 1, and M is an integer greater than 1.

Abstract: A service transmission method and apparatus are provided to establish a connection between an access and mobility management function network element and a secondary base station, when a master base station is not capable of continuing to provide a service for a terminal device. In an embodiment, an access and mobility management function network element determines that a master base station is not capable of continuing to provide a service for a terminal device. The access and mobility management function network element sends a mobility management context of the terminal device to a secondary base station, where the mobility management context is used by the secondary base station to perform mobility management on the terminal device. Therefore, a signaling connection between the access and mobility management function network element and the secondary base station can be quickly established, thereby ensuring service transmission and improving user experience.

Abstract: A method includes obtaining, by a data analytics network element, data of a terminal on an access network element and data of the terminal on an access and mobility management function network element, where the data of the terminal on the access network element includes a first identifier, and the access network element is an access network element, the data of the terminal on the access and mobility management function network element includes the first identifier, and the first identifier includes an identifier assigned by the access network element to the terminal, associating, by the data analytics network element, the data of the terminal on the access network element with the data of the terminal on the access and mobility management function network element based on the first identifier.

Abstract: This application provides a network connection configuration method and an apparatus. The method is as follows: After a terminal device obtains network configuration information of an application in the terminal device, the terminal device sends the network configuration information to a core network control plane network element, so that the core network control plane network element may determine a network connection that is of the application and is between the terminal device and the data network and that meets the network configuration information.

Abstract: A packet transmission method, including receiving, by a session management function network element, first access network tunnel information and second access network tunnel information that correspond to a first service, and sending a downlink forwarding rule to a user plane function network element, where the downlink forwarding rule includes the first access network tunnel information and the second access network tunnel information, and the downlink forwarding rule indicates the user plane function network element to replicate a received downlink packet of the first service, and send downlink packets of the first service through two paths respectively corresponding to the first access network tunnel information and the second access network tunnel information.

Abstract: A method includes: receiving, by a first session management function network element, first identification information from an access and mobility management function network element; obtaining information about a plurality of anchor user plane function network elements of a first session based on the first identification information; and sending, by the first session management function network element, the information about the plurality of anchor user plane function network elements to a branching point, where the branching point is a user plane function network element that is managed by the first session management function network element and that has a function of diverting traffic.

Abstract: This application provides a network connection configuration method and an apparatus. The method is as follows: After a terminal device obtains network configuration information of an application in the terminal device, the terminal device sends the network configuration information to a core network control plane network element, so that the core network control plane network element may determine a network connection that is of the application and is between the terminal device and the data network and that meets the network configuration information.