Abstract: A history information recording method, including obtaining, by a current secondary node, information about a history cell that a terminal device visits, where the information about the history cell comprises at least one of stay time of the terminal device in the history or moving speed information of the terminal device in the history cell, and performing, by the current secondary node, handover preparation based on the information about the history cell.

Abstract: A method and an apparatus for transmitting a timing difference. The method includes obtaining, by a master node, a measurement value of a timing difference between a first cell and a second cell, and sending, by the master node, the measurement value of the timing difference and identification information of the second cell to a secondary node, where the first cell is a primary cell corresponding to the master node, the second cell includes a primary secondary cell corresponding to the secondary node or another cell different from the primary secondary cell, and the identification information of the second cell includes a physical cell identifier (PCI) and frequency information of the second cell.

Abstract: A communication method and apparatus, to help improve efficiency of identifying a fake base station. The method includes: A terminal device receives configuration information sent by a network device, and then simultaneously measures, based on the configuration information, a channel state information-reference signal CSI-RS and a synchronization signal block SSB that are sent by a cell. When determining that a measurement result of the CSI-RS and a measurement result of the SSB of the cell satisfy a preset condition, the terminal device reports a measurement report to the network device, where the measurement report includes identification information of the cell, so that the network device identifies a fake base station.

Abstract: A handover method includes obtaining, by a source base station and a target base station, first indication information. The first indication information indicates a time during which a terminal device separately transmits data with the source base station and the target base station when the terminal device is handed over from a first cell of the source base station to a second cell of the target base station. The first cell and the second cell are intra-frequency neighboring cells. The method also includes sending, by the source base station, the first indication information to the terminal device.

Abstract: Example communication methods and apparatus are described. One example method includes determining, by a terminal device, that a connection failure occurs between the terminal device and a first cell, where the first cell is a cell of a first network device. The terminal device determines signal quality of a second cell of a second network device, where both the first network device and the second network device provide communication services for the terminal device. If the signal quality of the second cell is greater than or equal to a first preset threshold, the terminal device performs a connection recovery process between the terminal device and the first cell by using the second cell.

Abstract: Example communication methods and apparatus are described. One example communication method includes receiving broadcast information by a terminal device. The broadcast information includes a first parameter and a second parameter that are for a first cell. The first parameter is used for cell selection or cell reselection performed by a terminal device that supports supplementary uplink (SUL) carrier transmission, and the second parameter is used for cell selection or cell reselection performed by a terminal device that does not support SUL carrier transmission. The terminal device performs cell selection or cell reselection based on the first parameter when the terminal device supports SUL carrier transmission. The terminal device performs cell selection or cell reselection based on the second parameter when the terminal device does not support SUL carrier transmission.

Abstract: This application provides a reflective QoS flow characteristic-based communications method and apparatus. In the method, an access-network network element sends first information to a core-network network element, where the first information is used to indicate whether a data packet has a reflective QoS flow characteristic; and the access-network network element determines, based on the first information, whether there is a need to send a QoS flow identifier to a terminal. In this way, signaling overheads are reduced.

Abstract: Example measurement methods and apparatus are described. One example method includes obtaining a timer by a terminal device. The terminal device obtains two or more measurement configurations, where each of two or more measurement configurations includes a validity area and a measurement frequency corresponding to the validity area, and the validity area includes one or more cells. The terminal device measures, based on the measurement configuration, a measurement frequency corresponding to a validity area that matches a cell on which the terminal device camps, where the terminal device is in an idle state or in an inactive state, and the timer is not stopped and has not expired.

Abstract: Embodiments of this application provide a communications method, apparatus, and system. The method includes: A terminal device receives first information sent by a network device, where the first information includes access control information of services with N service attributes, and N is an integer greater than or equal to 1; and the terminal device determines, based on a first service that currently needs to be initiated and the first information, whether the terminal device can initiate the first service, where the N service attributes include at least a non-public network service, and the first service is any one of the services with the N service attributes. Therefore, access control on the terminal device is implemented when there is a non-public network service.

Abstract: A method, a base station, and a system for sending radio resource control (RRC) signaling are provided. The method includes a pico base station and a macro base station participate in configuration and generation of an RRC reconfiguration message; the pico base station establishes only one RRC entity that is used to generate a configuration parameter or an RRC entity; the RRC reconfiguration message cooperatively generated by the pico base station and the macro base station is uniformly sent by the macro base station to a user equipment (UE). According to the application, the UE can support an RRC reconfiguration message sent by the pico base station, only by establishing a signaling radio bearer (SRB) corresponding to the macro base station. Accordingly, design complexity and costs are lowered.

Abstract: This application provides a communication method and apparatus. The communication method includes: detecting that a terminal in an inactive state is in an out-of-service state, and determining a target cell of the terminal.

Abstract: This application provides a communication method and apparatus. The communication method includes: receiving measurement configuration information from a network device; determining whether a measurement task requires a measurement gap; and if the measurement task does not require the measurement gap, sending first measurement gap requirement information indicating that the measurement gap is not required to the network device, where the first measurement gap requirement information is used to deactivate or release configured measurement gap configuration information; and/or if the measurement task requires the measurement gap, sending second measurement gap requirement information indicating that the measurement gap is required to the network device, where the second measurement gap requirement information is used to activate or validate measurement gap configuration information corresponding to the second measurement gap requirement information.

Abstract: This application provides a transmission method and a data transmission apparatus, so as to avoid out-of-order of data packets.

Abstract: A communications method and apparatus. The communications method includes: transmitting a first request to a network device through a first resource, where the first request is used to request beam failure recovery of a first cell or is used to request system information of the first cell, the first resource is a resource of a second cell, and the first cell and the second cell are serving cells of a same terminal; and receiving a first response corresponding to the first request from the network device. Therefore, when a terminal has a plurality of serving cells, the terminal may transmit a request across cells (or across carriers), to improve transmission reliability.

Abstract: A communication method, a related device, and a system. The method includes: a first network device receives first information from a terminal device, where the first information includes a first delay and a second delay, the first delay is a delay of the terminal device on a first path, the second delay is a delay of the terminal device on a second path, and data packets transmitted on the first path and the second path belong to a first data radio bearer (DRB). The first network device determines an uplink delay of the first DRB based on the first information, a fourth delay, and a fifth delay, where the fourth delay is a network-side delay on the first path, and the fifth delay is a network-side delay on the second path.

Abstract: A communication method, apparatus, and system may include terminal device that receives first information from a core network device, where the first information is used to indicate whether the terminal device is to use a power-saving paging discontinuous reception cycle. The terminal device determines a paging discontinuous reception cycle of the terminal device based on the first information. Therefore, the terminal device avoids always selecting a shortest cycle as the paging discontinuous reception cycle, so that the paging discontinuous reception cycle determined by the terminal device is more appropriate, and power saving of the terminal device is facilitated.

Abstract: Embodiments of this application provide a data processing method, an access device, and a terminal device. The data communication method includes: A first access network device receives a handover request message from a second access network device, where the handover request message is to request a terminal device to hand over from a cell of the second access network device to a cell of the first access network device. The first access network device determines that robust header compression ROHC restriction processing needs to be performed. The data communication method further includes: The first access network device receives at least one packet from the second access network device and performs the ROHC restriction processing on a second packet in the at least one packet. The method can avoid a decompression failure of a terminal.

Abstract: Embodiments of this application disclose a communication method and a communications apparatus. A source base station instructs a terminal to hand over from the source base station to a target base station, and sends, to the terminal, configuration information of a second connection required for communication between the terminal and the target base station. The terminal maintains a first connection for communication with the source base station, and establishes the second connection for communication with the target base station based on the configuration information of the second connection. The solutions in the embodiments of this application reduces latency in a handover process.

Abstract: This application provides a communication method, a terminal, and a base station, so that communication is performed between a terminal and a cell during cell handover. The method includes: receiving, by a terminal from a first base station, a cell identity of a first cell, at least one beam parameter of the first cell, and a resource associated with the at least one beam parameter, where the first cell belongs to a second base station; further, determining a target beam parameter, and sending information on a resource corresponding to the target beam parameter; and receiving a response to the information by using a receive beam associated with the target beam parameter, so that communication can be performed between the terminal and a cell during cell handover.

Abstract: This application provides a communication method, a terminal, and an access network device. The method includes: sending, by a terminal in an RRC inactive state, first information to a first access network device, where the first information is used to indicate that the terminal is located in a wireless network area in which the terminal is in the RRC inactive state, and the first access network device is an access network device to which a cell in which the terminal is currently located belongs; receiving, by the terminal, a first message sent by the first access network device; and remaining, by the terminal, in the RRC inactive state based on the first message, or entering an idle state from the RRC inactive state based on the first message. According to the technical solutions of this application, performance of a communications system can be improved.