Abstract: A communication method and apparatus are disclosed. After receiving, from a source network device, a first message that enables a terminal device to handover from the source network device to a target network device, maintaining data transmission with the source network device; and sending a first report in response to subsequently detecting that a connection between the terminal device and the source network device fails. The first report includes first indication information used to determine whether the connection between the terminal device and the source network device fails before the terminal device accesses the target network device. In this way, the network device identifies, based on the information, a potential handover scenario that has a problem, so that a handover parameter is better adjusted or handover is more properly triggered, thereby improving a handover success rate of the terminal device.

Abstract: Embodiments of this application provide a communication method, apparatus, and system. The method includes: determining, based on area configuration information of a first cell of a network device and location information of a terminal device, a first sub-area corresponding to the terminal device, where the area configuration information indicates information about a plurality of sub-areas corresponding to the first cell, and the plurality of sub-areas include the first sub-area; and obtaining satellite ephemeris information corresponding to the first sub-area. In the foregoing solution, the sub-area is introduced, and the terminal device only needs to obtain the satellite ephemeris information corresponding to the sub-area in which the terminal device is located. This reduces an amount of satellite ephemeris information obtained by the terminal device, and therefore can reduce overheads of the terminal device.

Abstract: A handover method and a communication apparatus. A terminal device receives a first message, where the first message includes information about N candidate cells, the N candidate cells include N1 candidate cells and N2 candidate cells, the N1 candidate cells include a cell for which no conditional handover CHO execution condition information is configured, the N2 candidate cells include a cell for which the CHO execution condition information is configured, N and N2 are integers greater than 1 or equal to 1, and N1 is an integer greater than 0 or equal to 0. In a process of attempting to hand over from the source cell to the target cell, the terminal device maintains an RRC connection and/or data transmission with the source cell. Therefore, handover reliability is improved, a handover latency is reduced, and overall system performance is improved.

Abstract: Embodiments of this application provide a communication method and a communication apparatus, and relate to the communication field. The method includes: A first network device receives a first report from a terminal device, where the first report includes first information, and the first information indicates that the terminal device passively falls back from 2-step random access to 4-step random access, or actively falls back from 2-step random access to 4-step random access. The first network device performs processing based on the first report.

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: This application relates to the field of communication technologies, and discloses a communication method and apparatus. The terminal device determines, depending on a second information from a network device and whether a terminal device supports uplink service transmission through a second network device, a parameter used to perform cell selection or cell reselection.

Abstract: This application provides a handover method and apparatus. The handover method includes: A terminal device sends path information used to determine a first cell to a network device; and the terminal device receives conditional handover CHO configuration information that is corresponding to the first cell and that is sent by the network device, and determines a target cell based on the CHO configuration information corresponding to the first cell. According to the technical solutions provided in this application, a handover success rate can be improved when the terminal device performs cell handover.

Abstract: This application provides a radio resource management measurement method and apparatus. A network device sends measurement configuration information to a terminal device, where the measurement configuration information carries a first threshold; and the terminal device determines, based on a value relationship between a detection value and the first threshold, and signal quality of at least one neighboring cell, whether to report a measurement report. When performing RRM measurement, the terminal device can determine, based on a relationship between the first threshold and signal quality of a serving cell and/or a quantity of detected cells, and the signal quality of the at least one neighboring cell, whether to report the measurement report. This can prevent the terminal device from reporting the measurement report frequently, and avoid a case in which the terminal device does not report the measurement report in a timely manner, so that a measurement mechanism is more appropriate.

Abstract: A communication method and an apparatus. A terminal device determines height information, where a first parameter is related to the height information. The terminal device receives configuration information from a first network device, where the configuration information includes a correspondence between the height information and the first parameter. The terminal device determines, based on the height information, the first parameter corresponding to the terminal device. The first parameter includes one or more of a tracking area parameter, a radio access network notification area parameter, a cell selection or reselection parameter, and a measurement configuration parameter. Configuration information corresponding to a height of an uncrewed aerial vehicle is provided, to ensure that an uncrewed aerial vehicle terminal device at a high height obtains an effective configuration parameter, so that user experiences at different heights is improved.

Abstract: Embodiments of this application provide a cell reselection method and system, and an apparatus. The method includes: receiving reselection configuration information from a network device, where the reselection configuration information includes reselection trigger information, the reselection trigger information is used to trigger measurement for cell reselection, and the reselection trigger information includes reselection trigger time information or reselection trigger indication information; and performing measurement for cell reselection based on the reselection configuration information. In embodiments of this application, the reselection configuration information including the reselection trigger information is introduced.

Abstract: A communication method, apparatus, and system, the method including receiving first indication information from a first network device, where the first indication information is requests a terminal device to report first information, and reporting the first information to the first network device, where the first information includes related information in a conditional handover procedure.

Abstract: A mobility optimization method and a related apparatus are provided. The method includes: determining connection failure information; and sending the connection failure information and an identifier of a first cell to a first network device by using a radio resource control (RRC) message, wherein the identifier of the first cell comprises an identifier of a cell from which a reconfiguration message or a handover command message received by the terminal device comes or an identifier of a cell in which a connection failure occurs, wherein the connection failure information is in a form of a container in the RRC message and the identifier of the first cell is outside the container.

Abstract: Example communication methods and apparatus are described. One example communication method includes receiving indication information by a terminal device from a network device, where the indication information is used to indicate resource configuration information of a first uplink carrier and/or a second uplink carrier. The first uplink carrier and the second uplink carrier are different uplink carriers in a cell of the network device, and the first uplink carrier and the second uplink carrier are corresponding to one downlink carrier in the cell. The terminal device determines one uplink carrier from the at least one uplink carrier as a target carrier for performing random access based on the resource configuration information of the at least one uplink carrier.

Abstract: A method and system for mobility latency reduction in a hierarchical NR architecture is provided. In an embodiment, a method in a network component for handover of a UE includes configuring, by the network component, at least one TRP determined according to UE mobility information. The configuring the at least one target TRP is performed prior to the UE moving into a border area between the at least one target TRP and a first serving TRP. Configuring the at least one target TRP results in the at least one target TRP being configured to act as a secondary serving TRP to the UE. The method also includes configuring at least one target TRP and the UE with corresponding dedicated access resource and monitoring opportunities. The method also includes activating a connection and data communication between the UE and the at least one pre-configured secondary serving TRP.

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: This application discloses a communications method. The method may include: receiving, by a receiving party, indication information sent by a first device, where the indication information is used to indicate at least one intermediate sequence number; receiving a data packet of the bearer sent by the first device; and skipping the at least one intermediate sequence number based on the indication information, deciphering, by using the old key, a data packet that is located on the bearer and whose sequence number is followed by the at least one intermediate sequence number, and deciphering, by using the new key, a data packet that is located on the bearer and whose sequence number follows the at least one intermediate sequence number.

Abstract: This application provides a paging method and apparatus. The paging method may be applied to a terminal device including a first subscriber identity and a second subscriber identity, where the first subscriber identity corresponds to a first paging occasion, and the second subscriber identity corresponds to a second paging occasion. The method includes: First, the terminal device determines that a paging occasion collision occurs between the first paging occasion and the second paging occasion, and then the terminal device notifies a first access network device that the paging occasion collision occurs, where the first access network device corresponds to a first cell in which the terminal device is located by using the first subscriber identity.

Abstract: A communication method and apparatus, the method including performing, by a terminal device or a chip of the terminal device, sending a master cell group (MCG) failure message to a master node (MN) via a secondary node (SN) in response to detecting that a wireless connection fails, and further in response to a secondary cell group (SCG) not failing, performing cell selection in response to the SCG failing, and accessing a target cell in response to the target cell being a candidate cell pre-configured by the MN, where the target cell is a cell selected by the terminal device during the cell selection, where the SCG is a group of cells associated with the SN, and where the MCG is a group of cells associated with the MN.

Abstract: This application provide an information update method, and related communications apparatus. In this solution, a first network device determines first information, and sends the first information to a second network device. After receiving the first information, the second network device updates, based on the first information, configuration information corresponding to a first candidate cell to obtain configuration information corresponding to a second candidate cell. The first information is used to update the configuration information corresponding to the first candidate cell to obtain the configuration information corresponding to the second candidate cell, both the first candidate cell and the second candidate cell are managed by the second network device, the first candidate cell includes at least one cell, and the second candidate cell includes at least one cell.

Abstract: Embodiments of this application provide a communication method, device, and system, to reduce energy consumption of a terminal device and accelerate reselection performed by the terminal device. In this solution, a network device determines a plurality of sub-areas, and sends area configuration information to the terminal device. The terminal device receives the area configuration information, determines a first sub-area based on the area configuration information, and performs measurement based on information about one or more neighboring frequencies corresponding to the first sub-area. A geographical area range including the plurality of sub-areas includes a coverage area of a first cell, the area configuration information indicates information about the plurality of sub-areas, and the first sub-area is a sub-area in which the terminal device is currently located in the plurality of sub-areas.