Abstract: Embodiments of this application relate to the field of communication technologies, and disclose a communication method and apparatus, to optimize a multicast service processing procedure. The method may include: A first session management function network element receives a first message from a second session management function network element, where the second session management function network element corresponds to a multicast session, and the first message notifies that the multicast session is activated or notifies that the multicast session is released. The first session management function network element sends first information to an access and mobility management function network element based on the first message, where the first information includes identification information of the multicast session and/or indication information indicating group paging.

Abstract: This application provides a communication method and apparatus for a multicast/broadcast service. The method is performed by a network device and including: obtaining reference location information of a terminal representing a reference location of the terminal. When the reference location of the terminal is inside a service area of a first multicast/broadcast service, triggering a target access network device of the terminal to allocate, to the terminal, a data resource for transmitting the first multicast/broadcast service. When the reference location of the terminal is outside the service area, triggering the target access network device not to allocate, to the terminal, a data resource for transmitting the first multicast/broadcast service. According to the method, when the terminal moves into the service area or moves out of the service area, the network device can dynamically and flexibly interact with an access network device, thereby effectively saving network resources.

Abstract: A random access method, a base station, and a user equipment (UE) are disclosed. The random access method includes: transmitting a first message for random access for the UE, the first message including a preamble message and a signal message; receiving a second message and a fourth message for random access for the UE at a time and determining random access for the UE is successful upon receiving the second message and the fourth message; and upon reception of a second message configured to request the UE to transmit the signal message, transmitting a third message comprising the signal message, receiving the fourth message in response to the third message, and determining random access for the UE is successful upon receiving the fourth message.

Abstract: Embodiments of this application disclose a communication method, apparatus, and system. An example communication method includes: receiving, by an access network device from an access and mobility management function network element, information indicating to activate a multicast session corresponding to a multicast service; and sending, by the access network device based on the information, a paging message to a terminal in a radio resource control_inactive (RRC_inactive) state in the multicast session corresponding to the multicast service.

Abstract: A random access method, a base station, and a user equipment (UE) are disclosed. The random access method includes: transmitting a first message for random access for the UE, the first message including a preamble message and a signal message; receiving a second message and a fourth message for random access for the UE at a time and determining random access for the UE is successful upon receiving the second message and the fourth message; and upon reception of a second message configured to request the UE to transmit the signal message, transmitting a third message comprising the signal message, receiving the fourth message in response to the third message, and determining random access for the UE is successful upon receiving the fourth message.

Abstract: A communication method and apparatus, and a storage medium are provided, to resolve a problem in a conventional technology of discontinuity of a multicast/broadcast service of a UE during handover. The method includes: A target access network device receives first multicast/broadcast service data from a source access network device and second multicast/broadcast service data from a core network device; and if determining that the first multicast/broadcast service data is synchronous with the second multicast/broadcast service data, the target access network device sends the second multicast/broadcast service data to a terminal device, so that the continuity of the multicast/broadcast service of the UE during handover is ensured as much as possible.

Abstract: Embodiments of this application provide a multicast/broadcast service communication method and an apparatus, and relate to the communication field, to reduce network resource overheads. The method is as follows: A terminal device determines a first multicast/broadcast service, where the first multicast/broadcast service is a multicast/broadcast service that the terminal device is to leave. The terminal device sends a first message, where the first message carries identification information of the first multicast/broadcast service. Embodiments of this application are applied to a mobile communication system such as 5G.

Abstract: A data transmission method and apparatus. The method includes: a source access network device that receives an end marker from a core network device through a transmission tunnel of a PDU session of a first terminal device, where the PDU session is associated with a first multicast/broadcast service; and in response to the end marker, the source access network device determines, based on the association between the PDU session and the first multicast/broadcast service, that the end marker acts on the first multicast/broadcast service of the first terminal device, to stop sending data of the first multicast/broadcast service to a target access network device through a forwarding tunnel of the first terminal device.

Abstract: A random access method, a base station, an UE and a device with a storage function are disclosed. The random access method includes: the base station receiving a first message transmitted by the UE, the first message including a preamble message and a signal message; decoding the preamble message and the signal message respectively; if the decoding of preamble message is succeeded, but the decoding of signal message fails, the base station transmits a second message to the UE, and storing the signal message of decoding failure, the second message configured to request the UE to retransmit the signal message; receiving the third message transmitted by the UE, the third message including the signal message; using a chase combine mechanism to decode the third message according to the stored signal message in the first message. The present disclosure save time and improve the efficiency of random access.

Abstract: This application provides a multicast service transmission method and apparatus, to deliver a multicast service regardless of whether there is a device supporting multicast in a system, so as to improve flexibility and reliability of the multicast service transmission. The method performed by a session management network element includes: receiving a first message or a second message, where the first message requests to add a terminal device to a multicast service, the second message is used to update a PDU session of the terminal device, and the PDU session is associated with the multicast service; and determining, based on multicast capability information of the terminal device and/or multicast capability information of an access network device, a delivery mode of the multicast service, where the access network device is an access network device currently accessed by the terminal device or a target access network device of the terminal device.

Abstract: A random access method, a base station, an UE and a device with a storage function are disclosed. The random access method includes: the base station receiving a first message transmitted by the UE, the first message including a preamble message and a signal message; decoding the preamble message and the signal message respectively; if the decoding of preamble message is succeeded, but the decoding of signal message fails, the base station transmits a second message to the UE, and storing the signal message of decoding failure, the second message configured to request the UE to retransmit the signal message; receiving the third message transmitted by the UE, the third message including the signal message; using a chase combine mechanism to decode the third message according to the stored signal message in the first message. The present disclosure save time and improve the efficiency of random access.