Abstract: The present disclosure relates to communication methods and communications apparatus. In one example communication method, a terminal device obtains measurement configuration information, where the measurement configuration information is used to indicate a target frequency for which logged minimization of drive tests (logged MDT) measurement is performed by the terminal device. The terminal device performs the logged MDT measurement for the target frequency.

Abstract: A communications method and apparatus. The method includes receiving, by a centralized unit (CU), from a distributed unit (DU) a correspondence between an absolute time and a radio frame number, and sending, by the CU, a first absolute time corresponding to a first radio frame number to an user equipment (UE).

Abstract: Embodiments of this application disclose a random access method. The method includes: obtaining, by a first network device, resource information corresponding to a target service unit, where the resource information is used to indicate a resource to be used, by a user equipment (UE) that has established a connection to the first network device, to send a physical random access channel (PRACH) via the target service unit, and the target service unit is a cell to be accessed by the UE or at least one beam to be accessed by the UE; and sending, by the first network device, a notification message to the UE, where the notification message includes the resource information.

Abstract: This application provides a communication method and apparatus, and a system, to protect security and user privacy in a data transmission process. After determining to establish a radio resource control (RRC) connection in anonymous mode, a terminal device sends a request to an access network device, to request to establish the RRC connection in anonymous mode, so that the access network device establishes the RRC connection in anonymous mode to the terminal device. The solutions in this application may be applied to a communications system, for example, may be applied to a 5th generation 5G network.

Abstract: The present disclosure relates to delay measurement methods and apparatus. In one example method, a first communications device receives a data unit from a second communications device, where the data unit includes time information, the time information is used to indicate a first moment at which the second communications device sends the data unit, and the time information indicates the first moment based on a part of bits of a frame number. The first communications device determines a delay from the second communications device to the first communications device based on the first moment and a second moment, where the second moment is a moment at which the first communications device receives the data unit.

Abstract: This application provides a minimization of drive tests (MDT) measurement solution, which may be used to implement an MDT measurement of a network device with an architecture in which a central unit (CU) entity and a distributed unit (DU) entity are separated. A centralized unit control plane (CU-CP) determines configuration information, and sends the configuration information to a centralized unit user plane (CU-UP) of the network device. The configuration information is used to perform an MDT measurement on a measurement object. The solution in this application may be applied to a communications system, for example, may be applied to a 5th generation (5G) network.

Abstract: This disclosure discloses methods, apparatuses, and systems for performing handover. One method comprises: receiving, by a target access network device after a mapping relationship between a quality of service (QoS) flow of a terminal device and a data radio bearer (DRB) changes, a handover request from a source access network device, wherein the handover request comprises indication information for requesting to establish a tunnel; and sending, by the target access network device to the source access network device, information about the tunnel for the target access network device to receive one or more data units from the source access network device after the mapping relationship between the QoS flow and the DRB changes.

Abstract: A transmission method is implemented by a communications device including a first functional entity and a second functional entity. A first carrier is configured for the first functional entity, and a second carrier is configured for the second functional entity. The second functional entity obtains first information, where the first information is first control information of the first functional entity, or is the first control information and second control information of the second functional entity, the first control information includes a first identifier, and the first identifier is used to indicate the first carrier; and the second functional entity sends the first information by using the second carrier.

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: Example communications systems, methods and network devices are described. One example method includes sending a first message by a first access network device to a core network device to enable the core network device to send a second message to a second access network device, where the first message includes an identity of the second network device. The first message is used to request for X2 transport network layer (TNL) configuration information of a third network device, and the third network device is a network device that has established an X2 connection to the second network device. The first network device receives the X2 TNL configuration information of the third access network device from the second access network device. Therefore, a network device connected to a control plane of a core network can obtain TNL addresses of more network devices that are not connected to the control plane of the core network.

Abstract: The present disclosure relates to data transmission methods and apparatus to implement quality of service (QoS) flow-based data transmission in an architecture in which a central unit-control plane (CU-CP) and a central unit-user plane (CU-UP) are separated from each other. In one example method, when receiving data of a QoS flow, the CU-UP may send a QoS flow identity (ID) and a protocol data unit (PDU) session ID that are of the data of the QoS flow to the CU-CP, where a PDU session corresponding to the PDU session ID includes the data of the QoS flow.

Abstract: Embodiments of the present invention relate to communications technologies, and provide a data transmission method and an apparatus. The method includes: sending, by a base station, a grouping instruction to a target terminal, where the grouping instruction is used to group, in a preset grouping manner, terminals in a cell in which the target terminal is located into N groups, totally or partially different resources are allocated to terminals in different groups of the N groups, and a resource corresponding to an ith group of the N groups is used by a terminal in the ith group in uplink non-scheduled transmission; and receiving data that is sent by the target terminal using a target resource. In the solutions, terminals in a cell are grouped, and terminals in a same group contend for a resource allocated to the group. This mitigates resource collision when an uplink non-scheduled transmission solution is used.

Abstract: A method includes obtaining, by a network device, scheduling time information of at least one beam, where the scheduling time information of the at least one beam includes scheduling time information of a first beam currently accessed by a terminal, and is used to instruct the terminal to receive or send a signal at a scheduling time indicated by the scheduling time information of the at least one beam; and sending, by the network device, first indication information to the terminal, where the first indication information is used to indicate the scheduling time information of the at least one beam.

Abstract: A data transmission method and apparatus are disclosed, where the method includes: determining, by a source base station, first data and a radio air interface protocol sequence number of a data unit used to carry the first data, where the first data includes data that is not acknowledged by a terminal for correct reception during data transmission between the source base station and the terminal; and sending, by the source base station, the first data and the radio air interface protocol sequence number to a target base station; where a core network connected to the target base station is different from a core network connected to the source base station.

Abstract: This application provides a measurement configuration method and an apparatus. The method includes: determining that a serving cell changes from a first cell to a second cell; and updating or deleting a current measurement window configuration. The measurement window configuration is used to indicate a time domain position at which a terminal device measures a downlink reference signal. According to the solution provided in this application, when the serving cell of the terminal device changes, the current measurement window configuration of the terminal device is updated or deleted.

Abstract: Embodiments of this application provide a data sending method, a data receiving method, and a device. In the data sending method, a receive end device performs a DRX operation at a low frequency based on a DRX parameter; and receives, in a time indicated by the DRX parameter, first indication information sent by a transmit end device, where the first indication information is used to instruct the receive end device to prepare to receive data at a high frequency. In this process, the receive end device performs the DRX operation only at the low frequency, and starts beam tracking only after receiving the first indication information that instructs the receive end device to receive the data at the high frequency, to avoid unnecessary beam tracking and save power of the receive end device.

Abstract: Embodiments of this patent application provide a data transmission method and an apparatus for determining, by a core network (CN) device, a length of a quality of service flow identifier (QFI) used when a protocol data unit (PDU) session is established or modified for a terminal device; and sending, by the CN device, a first message to a radio access network (RAN) device, where the first message includes length information of at least one QFI. After receiving the first message from the core network CN device, the access network RAN sends a second message to the terminal device, where the second message includes the length information of the at least one QFI.

Abstract: Example handover methods and apparatus are described. One example method includes generating a handover request message or a handover requirement message by a source radio access network (RAN) device. The handover request message includes a first mapping relationship between downlink transmission of a quality of service (QoS) flow and a data radio bearer (DRB) and a second mapping relationship between uplink transmission of the QoS flow and a DRB that are configured by the source RAN device for a terminal device, where the two mapping relationships are different. The source RAN device sends the handover request message to a target RAN device, and forwards data of the terminal device on the source RAN device to the target RAN device in a process in which the terminal device is handed over from the source RAN device to the target RAN device.

Abstract: Various embodiments provide a resource allocation method and an apparatus. In those embodiments, a terminal device obtains a first parameter indicating a maximum service data volume to be provided by an access network device for a first service in a first time length; and determines, based on the maximum service data volume, a resource of a media access control protocol data unit MAC PDU, the resource being occupied by buffered data of the first service. In those embodiments, the terminal device determines, based on the maximum service data volume of the first service, the resource of the MAC PDU. Compared with a conventional method, the maximum service data volume of the first service is considered. This helps improve reasonableness of allocating the resource of the MAC PDU to the data of the first service.

Abstract: The embodiments of the present disclosure disclose a small data transmission method and a related device and system. The method may include: broadcasting, by a base station, a paging message, where the paging message carries UE identifiers of a plurality of to-be-paged user equipment UE and small data sent to at least one of the to-be-paged UEs, and the small data is data whose data volume is less than a preset data volume threshold. In the present disclosure, small data may be sent to to-be-paged UE while the base station pages the UE, to reduce signaling and time overheads for sending the small data and improving communication efficiency.