Abstract: This application provides a communication method, a network device, and a terminal. The communication method includes: determining, by a first network device, at least one candidate target cell and first configuration information, where the first configuration information is used to trigger a terminal to determine one of the at least one candidate target cell as a to-be-handed-over-to cell; and sending, by the first network device, a first message to the terminal, where the first message includes first cell indication information and the first configuration information, and the first cell indication information is used to indicate the at least one candidate target cell.

Abstract: A first terminal receives first sidelink (SL) carrier configuration information from a second terminal, the first SL carrier configuration information includes first bandwidth part (BWP) configuration information, and the first BWP configuration information includes one or more first resource pools; the first terminal performs unicast connection communication with the second terminal based on the first BWP configuration information.

Abstract: This application provides a handover method, a communication apparatus, and a computer storage medium. The method includes: A first access network device determines, based on coverage information of a neighboring access network device and route information of a terminal, a second access network device that can provide a communication service for the terminal, and sends a handover request message to the second access network device. Adaptation between a moving path of the terminal and a coverage range of a neighboring base station is considered in a process of determining a target access network device or a candidate target access network device, so that the terminal can be handed over to an access network device that matches the moving path of the terminal.

Abstract: A communication method includes: a first communication apparatus obtains first configuration information and sends the first configuration information to a second communication apparatus, where the first configuration information includes configuration information of a first sidelink radio bearer which is used to carry a first unicast service between the first communication apparatus and the second communication apparatus, and the first sidelink is a radio link between the first communication apparatus and the second communication apparatus.

Abstract: This application provides a communication method in multi-rat dual connectivity, an apparatus, and a system. In the method, when a PDCP SN length of a bearer is changed, an SN sends a PDCP SN length change indication to an MN, so that the MN and the SN can generate release and addition configuration information for the bearer for a terminal, thereby completing the change of the PDCP SN length.

Abstract: A method includes: a first terminal device receives first information from a network device, where the first information includes an indication information of a first unicast connection and a reference signal configuration corresponding to the first unicast connection, the reference signal configuration is used by the first terminal device to send a reference signal to a second terminal device; and the first terminal device sends the reference signal to the second terminal device on a sidelink based on the reference signal configuration.

Abstract: Embodiments of this application provide a sidelink communication method and device. The method includes: A first communication device receives configuration information from a network device. The configuration information is used by the first communication device to detect consistent listen before talk LBT failures that occur in a first resource pool, the configuration information is associated with a first carrier or the first resource pool, and the first resource pool belongs to the first carrier. In addition, the first communication device sends first indication information to the network device. The first indication information indicates the first resource pool in which the consistent LBT failures occur. In this method, validity of a transmission resource of a sidelink resource pool or carrier can be ensured, and network communication reliability can be improved.

Abstract: This application provides a communication method and an apparatus, to improve uplink transmission efficiency and performance. The method includes: A first terminal apparatus receives first configuration information from a network device, where the first configuration information indicates an identifier of a second terminal apparatus and information about a first frequency band, and the first frequency band is a frequency band supported by the second terminal apparatus; and the first terminal apparatus transmits uplink data to the network device on the first frequency band and a second frequency band that is supported by the first terminal apparatus.

Abstract: This application provides a relay communication method, a communication apparatus, and a communication system, to effectively improve efficiency of accessing a cell of a network device by a remote terminal. The method is applied to a communication system including a first terminal, a second terminal, and a third terminal, and the first terminal is a relay device used by the second terminal to access a network device. The method includes: The first terminal receives system information from the network device, and determines, based on the received system information, that the second terminal fails to camp on a first cell of the network device. The first terminal sends first indication information to the second terminal, where the first indication information indicates to break a sidelink between the first terminal and the second terminal, or the first indication information indicates that the second terminal fails to camp on the first cell.

Abstract: A communication method, apparatus, and system. Relay UE receives a first MAC PDU sent by a base station. The first MAC PDU includes identity information and control information of the remote UE. The relay UE sends a second MAC PDU to the remote UE through a sidelink. The second MAC PDU includes second information, and the second information indicates that the second MAC PDU includes the control information.

Abstract: Embodiments of this application provide a sidelink communication method and device. The method includes: A communication device obtains configuration information and a transmission resource. The configuration information includes configuration of a first resource pool and configuration of a second resource pool. According to the method, it can be ensured that the transmission resources of the first resource pool and the second resource pool are used to send different information.

Abstract: Embodiments of this application provide a relay communication method, apparatus, and system. In the method, when a first terminal device communicates with a second terminal device through a relay device, the first terminal device sends an RB configuration to the second terminal device by using the relay device. The RB configuration includes the first identifier and a PDCP entity configuration; or the RB configuration includes the PDCP entity configuration, and the PDCP entity configuration includes the first identifier. According to the method in this application, the first terminal device and the second terminal device may perform data transmission by using the same security protection parameter, to ensure correctness and effectiveness of data security protection in a process in which the first terminal device communicates with the second terminal device through the relay device.

Abstract: The present disclosure relates to mode switching methods, data flow splitting methods, and apparatus. One example mode switching method includes generating, by a first device, first indication information, where a packet data control protocol (PDCP) entity in the first device is connected to at least two radio link control (RLC) entities in a second device, and sending, by the first device, the first indication information to the second device, where the first indication information is used to indicate that transmission between a first RLC entity in the at least two RLC entities and the PDCP entity in the first device is to be canceled. The second device stops the transmission between the first RLC entity and the PDCP entity based on the first indication information.

Abstract: A first terminal device obtains a first parameter related to a first air interface, and then determines, based on the first parameter, that first frequency information of a second air interface has a highest priority, where the first air interface is a radio interface between the first terminal device and a second terminal device, and the second air interface is a radio interface between the first terminal device and a network device.

Abstract: Embodiments of this application provide a method including: in a process of handing over a terminal side device, a source access network side device of the terminal side device and a target access network side device interacts with time division multiplexing (TDM) pattern configuration or uplink power configuration.

Abstract: A communication method and apparatus, and a system. A first terminal device obtains first information, where the first information includes a first multicast and broadcast service MBS service identifier and first sidelink SL resource information. A mapping relationship exists between the first MBS service identifier and the first SL resource information. A first MBS is an MBS supported by a first relay terminal device, and the first SL resource information is usable for transmitting data of the first MB S to the first terminal device. The first terminal device receives, based on the first SL resource information, the data that is of the first MBS and that is sent by the first relay terminal device. The first terminal device transmits MBS data in a scenario in which a relay terminal device supports an MBS service.

Abstract: Example configuration methods and apparatus are described. An example communications system includes a master node and a secondary node that jointly provide a service for a terminal. One example method includes generating configuration information for a signaling radio bearer (SRB) by the secondary node, where the SRB is used to transmit a radio resource control (RRC) message between the secondary node and the terminal. The secondary node sends the configuration information for the SRB to the master node, so that the configuration information for the SRB is sent to the terminal through the master node. The secondary node receives a result of configuring the SRB by the terminal by using the configuration information for the SRB. In this way, the SRB can be established on the secondary node, and used for RRC message transmission between the secondary node and the terminal.

Abstract: This application provides a communication method, apparatus, and system. The method includes: determining first information, where the first information includes one or more types of information about an associated beam for a random access success of the terminal device, or, information about an associated uplink carrier for a random access success of the terminal device, and/or includes information about a random access channel RACH resource for a random access failure of the terminal device, and the random access failure of the terminal device includes one or more of a 2-step random access failure, a 4-step random access failure, a dedicated RACH resource random access failure, or a common RACH resource random access failure; and sending the first information.

Abstract: A communication method for data transmission in the internet of vehicles V2X and a related device. The method includes a first terminal device that receives first information from a first radio access network device, where the first information includes service information of a service of the first terminal device and a resource configuration mode on a sidelink, and there is a correspondence between the service information and the resource configuration mode on the sidelink. The first terminal device transmits, based on the correspondence, data corresponding to the service information on a sidelink transmission resource configured based on the resource configuration mode. The service information may be reliability information.

Abstract: This application provides a system information SI transmission method and apparatus. The method includes: The first terminal device receives a first request message sent by the one or more second terminal devices. The first request message is used to request to obtain M system information blocks SIBs or system information SI messages of a serving cell. The first terminal device determines N destination identifiers corresponding to the M SIBs or SI messages, where N is an integer greater than or equal to 1, and N?M. The first terminal device sends, based on the N destination identifiers, the M SIBs or SI messages to the one or more second terminal devices in a broadcast or multicast manner. According to the method, the SI may be transmitted on an SL in the multicast or broadcast manner. This improves SI transmission efficiency and SI update efficiency.