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: In a media data transmission method, an access network device receives layered coding information of a media flow, where the media flow is a target service; the access network device determines a plurality of multicast groups based on the layered coding information and information about terminal devices that access the target service; and the access network device sends a media data packet of the target service to the terminal devices based on the plurality of multicast groups. By using the method, multicast grouping may be performed on a plurality of terminal devices that access a same service, and further differentiated transmission is performed on media data of the same service. This improves a data transmission speed of the access network device, and improves a data throughput in a signal coverage area of the access network device.

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: 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: Embodiments of this application provide a method and an apparatus for adjusting a media parameter. The method includes: A terminal device obtains network information from a network data analytics function network element, where the network information includes one or more of the following: network performance prediction information or a media parameter, the network performance prediction information indicates prediction of a network status, and the media parameter is used for controlling, selecting, transmitting, or buffering media data. The terminal device processes the media data based on the network information. In embodiments of this application, a freezing phenomenon can be reduced by adjusting a media parameter, and quality of experience of a user can be improved.

Abstract: This application provides a method for controlling a terminal device to access a network, and a communication apparatus. The method includes: An access network device sends, to a mobility management network element, identification information of a network selected by a terminal. When a core network does not determine whether the terminal device is allowed to access the network, the mobility management network element sends, to the terminal device, information indicating not to initiate a service. According to the method, the terminal device is prevented from initiating a service before the core network verifies whether the terminal device is allowed to access the network, so that compliance with regulatory requirements is ensured.

Abstract: Embodiments of the present disclosure provide 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: This disclosure provides a communication method, and a corresponding apparatus. In the method, a terminal device obtains association information between first traffic description information and second traffic description information; determines the first traffic description information and the second traffic description information; and sends a first request message and a second request message that include same session pair information to establish redundant sessions. The first request message is used to request to establish a first session corresponding to the first traffic description information and the second request message is used to request to establish the second session corresponding to the second traffic description information.

Abstract: A data packet transmission method includes receiving, by a first network element, a first data packet of a first service from an application server. The method also includes determining, by the first network element, first sequence information of a second data packet. The second data packet is a to-be-discarded data packet of the first service. The first sequence information indicates a sequence of the second data packet. The method further includes determining, by the first network element, a third data packet. The third data packet includes the first sequence information. The method additionally includes sending, by the first network element, the third data packet to a terminal device.

Abstract: A service packet transmission method and apparatus, the method including receiving, by the source mobile edge computing network element, after a source mobile edge computing network element receives a second uplink service packet, a first uplink service packet sent by a source user plane network element and that is from a target user plane network element, where the second uplink service packet is the last uplink service packet sent by the source mobile edge computing network element to a source application server, sending, by the source mobile edge computing network element, the first uplink service packet to a target mobile edge computing network element, and sending, by the source mobile edge computing network element, first indication information to the target mobile edge computing network element, the first indication information indicating that the sending of the first uplink service packet by the source mobile edge computing network element ends.

Abstract: This disclosure provides session processing methods and apparatuses. In an implementation, a method comprises receiving, from an application function apparatus, a request that comprises a continuity requirement of an application indicating whether a service of the application needs to remain uninterrupted for a user equipment when the user equipment moves, determining, for the application, a session and service continuity mode that satisfies the continuity requirement of the application, and sending policy information that comprises the session and service continuity mode.

Abstract: This application provides methods and communication apparatus for transmitting a data packet of a media stream. The method can include an access network element receiving M data packets of a media stream from a user plane network element. When a network resource of the access network element cannot satisfy a transmission requirement of a terminal device, the access network element drops N data packets with lower priorities in the M data packets, where N?M. The access network element sends, to the terminal device, a data packet that is not dropped and sequence numbers that represent sending sequences of the data packets and that are carried in the N data packets, and receives, from the terminal device, an ACK feedback for the sequence numbers carried in the N data packets. In the solutions discussed herein, video playback experience on a user side can be substantially ensured.

Abstract: A communication method and apparatus, and a computer-readable storage medium. First request information is received from a terminal device, where the first request information includes first application identification information. Second information is determined based on the first application identification information and first information obtained from a session management function network element, where the second information includes extended mechanisms for DNS client subnet option or address information of a local DNS resolver. DNS request information is sent to a central DNS server or the local DNS resolver based on the second information, where the DNS request information includes the first application identification information, and the DNS request information is usable to obtain address information of an application server.

Abstract: A local network accessing method and apparatus are provided. The local network accessing method comprises sending a trigger message to a terminal, the trigger message is for triggering the terminal to establish a session, receiving a first message from the terminal, the first message requesting to establish a first session, and the first session is for the terminal to access a target local network, determining a target network access identifier based on the first message, the target network access identifier indicating the target local network, determining a first session management function network element based on the target network access identifier, and sending the target network access identifier to the first session management function network element, the target network access identifier is for the first session management function network element to determine a target user plane function network element.

Abstract: In a re-allocation process of a first user plane function network element to a second user plane function network element, a session management function network element sends a respective session modification request to each anchor user plane function network element of a plurality of anchor user plane function network elements, where each session modification request includes information about the second user plane function network element; and indicates to only a first anchor user plane function network element in the plurality of anchor user plane function network elements to send an end marker; or sends the end marker to only the first anchor user plane function network element.

Abstract: A transmission method and apparatus related to the field of communications technologies and include obtaining, by a session management network element, transport network capability list information, where the transport network capability list information indicates whether a transport network supports high-reliability transmission, and the transport network is a network between an access device and a user plane network element, and managing, by the session management network element, a user plane connection, of a terminal, between the access device and the user plane network element based on the transport network capability list information, where the user plane connection is usable for transmitting a service flow packet of the terminal.

Abstract: This application provides a method and an apparatus for determining an air interface latency and relates to the field of communications technologies. In the method, an access network device obtains an air interface latency of a downlink data packet and schedules the downlink data packet based on the air interface latency of the downlink data packet. The air interface latency of the downlink data packet is calculated based on a round-trip latency, and the round-trip latency is a latency from when a terminal sends an uplink data packet to when the terminal receives the downlink data packet corresponding to the uplink data packet. In the method, the access network device may schedule the downlink data packet based on the air interface latency of the downlink data packet, so as to precisely control a latency in uplink and downlink data transmission.

Abstract: A cell selection method includes obtaining measurement results of N cells. The cell selection method also includes obtaining cell selection assistance information. The cell selection assistance information includes identifiers of L slices corresponding to M sessions of a terminal device and slice capability information of the N cells, the slice capability information of the N cells includes identifiers of slices supported by the N cells, and M, L, and N are positive integers. The cell selection method further includes performing cell selection or cell reselection based on the measurement results of the N cells and the cell selection assistance information.

Abstract: Embodiments of this disclosure provide a communication method and apparatus, to reduce a waiting delay during transmission of retransmitted data and out-of-order data. In this method, a user plane function network element may receive first data and second data, determines, based on first information, that the second data is retransmitted data of the first data, and sends indication information to an access network network element. The indication information herein may indicate that the second data is the retransmitted data, or indicate a sending priority of the second data. Based on this solution, the access network network element may send the first data and the second data based on the indication information, and may preferentially send the retransmitted data to reduce the waiting delay during data transmission.

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.