Abstract: A method includes sending, by an access network device, first indication information to a terminal device, where the first indication information indicates a last packet in one or more first-type packets or a first packet in one or more second-type packets, where the first-type packet is enciphered using a first cipher key, and the second-type packet is enciphered using a second cipher key.

Abstract: A measurement method includes sending, by a first device to a second device, a message including a first configuration, wherein the first configuration indicates that a first event triggers the second device to send a first measurement message. The first event includes at least a channel quality of a measurement object is less than a first threshold, the channel quality of the measurement object is lower than a channel quality of a serving cell of the second device, the channel quality of the measurement object is less than the first threshold, and the channel quality of the serving cell of the second device is greater than a second threshold, or the channel quality of the measurement object is lower than the channel quality of the serving cell of the second device and the channel quality of the serving cell of the second device is greater than the second threshold.

Abstract: A communication method includes: sending, by a first device, a handover request message to a second device, and receiving a handover acknowledgement message returned by the second device, where the handover acknowledgement message carries common system information of the second device; sending, by the first device, a handover command to a terminal, where the handover command includes the common system information of the second device; sending, by the first device, a second message to the terminal based on a first message, so that the terminal obtains changed communications system information of the second device based on the second message, where the first message is sent by the second device, and the first message is used to indicate a change occurring in the common system information of the second device.

Abstract: The method includes: handing over a first terminal device from a second terminal device to a network device; receiving, by the first terminal device, a first packet data convergence protocol PDCP data packet sent by the network device; and if the first PDCP data packet is a target PDCP data packet, submitting, by the first terminal device, a second PDCP data packet, where the target PDCP data packet is a PDCP data packet sent by the network device based on a transmission status report, and the transmission status report is a status report sent by the first terminal device or the second terminal device to the network device.

Abstract: A radio bearer configuration method, an apparatus, and a system. The method includes: determining that a first sidelink radio bearer and a second sidelink radio bearer that are used during communication between the second terminal and a first terminal are associated with each other; and sending a first message to the first terminal, where the first message includes first indication information, and the first indication information is used to indicate that the first sidelink radio bearer is associated with the second sidelink radio bearer, where the first sidelink radio bearer is used by the first terminal to send first sidelink service data to the second terminal, and the second sidelink radio bearer is used by the second terminal to send a first radio link control RLC status report for the first sidelink service data to the first terminal.

Abstract: Embodiments of this application relate to the communications field, and provide a route update method, the method, comprising: sending a medium access control protocol data unit (MAC PDU), wherein the MAC PDU comprises a first buffer status report (BSR); and canceling, in response to the sending of the MAC PDU, a scheduling request triggered prior to the MAC PDU assembly, wherein the first BSR comprises a buffer status up to the last event that triggers a BSR prior to the MAC PDU assembly.

Abstract: A data processing method, where a first device communicates with a second device using a relay node, where the relay node does not have a Packet Data Convergence Protocol (PDCP) entity, and the method includes transmitting, by the first device, a first data unit group, where the first data unit group is in a first sequence range, receiving, by the first device, first information using the relay node, where the first information indicates a data unit that the second device has received or has not received in the first data unit group, determining, by the first device, a second sequence range based on the first information.

Abstract: A method and a device are provided. The method includes: selecting, by user equipment, a random access preamble from a random access preamble set, and selecting a random access channel resource from a random access channel resource set; sending, by the user equipment, the random access preamble by using the random access channel resource; and receiving, by the user equipment, a random access response message on a first downlink bandwidth part; wherein at least one of the random access preamble set or the random access channel resource set corresponds to the first downlink bandwidth part, and the random access channel resource includes at least one of a random access channel time domain resource or a random access channel frequency domain resource.

Abstract: A measurement configuration determining method includes receiving, by a terminal device, a first message from a network device. The first message includes a first relationship, the first relationship indicates an association relationship between an index of a reference signal and measurement configuration information. The measurement configuration information is adapted for the terminal device to perform a measurement and the terminal device determines the measurement configuration information based on the index.

Abstract: A data transmission method and related devices. The method includes: handing over a first terminal device from a second terminal device to a network device; receiving, by the first terminal device, a first packet data convergence protocol (PDCP) data packet sent by the network device; and if the first PDCP data packet is a target PDCP data packet, submitting, by the first terminal device, a second PDCP data packet, where the target PDCP data packet is a PDCP data packet sent by the network device based on a transmission status report, and the transmission status report is a status report sent by the first terminal device or the second terminal device to the network device.

Abstract: This application provides a communication method and a communications device. The method includes: A first device receives a first message sent by a second device. The first message is used to indicate a bearer configuration of a bearer of the first device and an initial status of the bearer configuration, and the bearer configuration includes a first bearer configuration and/or a second bearer configuration. The first device determines the bearer configuration and the initial status of the bearer configuration based on the first message. According to the technical solutions in embodiments of this application, a bearer configuration of a terminal device and an initial status of the bearer configuration of the terminal can be indicated.

Abstract: A route update method relating to a communications field includes: sending a medium access control protocol data unit (MAC PDU), wherein the MAC PDU comprises a first buffer status report (BSR); and canceling, in response to the sending of the MAC PDU, a scheduling request triggered prior to the MAC PDU assembly. The first BSR comprises a buffer status up to the last event that triggers a BSR prior to the MAC PDU assembly.

Abstract: The method is applied to a communications system including a first network device, a second network device, and a terminal device. The terminal device is communicatively connected to the first network device and the second network device respectively. The method includes: sending, by a network device, a first message to the terminal device, where the first message is used to determine that the terminal device stops communication with the first network device, or the first message is used to determine that the terminal device releases a protocol stack and a data radio bearer that are corresponding to the first network device; and the network device is the first network device or the second network device. Therefore, power consumption of the terminal device or the first network device and waste of air interface resources can be reduced, and flexibility can effectively be improved in a communication process.

Abstract: A data transmission method and related devices. The method includes: handing over a first terminal device from a second terminal device to a network device; receiving, by the first terminal device, a first packet data convergence protocol (PDCP) data packet sent by the network device; and if the first PDCP data packet is a target PDCP data packet, submitting, by the first terminal device, a second PDCP data packet, where the target PDCP data packet is a PDCP data packet sent by the network device based on a transmission status report, and the transmission status report is a status report sent by the first terminal device or the second terminal device to the network device.

Abstract: A bandwidth part processing method includes receiving, by a terminal, a first information and a second information from a network device. The first information indicates that at least one default bandwidth part (BWP) corresponds to at least two active BWPs, the second information indicates that the at least two active BWPs correspond to at least one first timer, and the at least one first timer is useable by the terminal to perform deactivation processing on at least one of the at least two active BWPs. The method further includes performing, by the terminal, deactivation processing on the at least one of the at least two active BWPs, and activation processing on a BWP in the at least one default BWP based on the first and second information, or performing deactivation processing on the at least one of the at least two active BWPs based on the first and second information.

Abstract: This application provides a resource allocation method and a communications device. The method includes: receiving, by a communications device, logical channel configuration information sent by a network devicetime duration; and determining, by the communications device based on the logical channel configuration information, whether to allocate a resource to a data packet on the logical channel. According to the resource allocation method provided in this application, when needing to allocate a transmission resource to the data packet on the logical channel, the communications device may determine, based on the time duration of the logical channel and a data volume of data that can be transmitted on the logical channel within the time duration that are in the logical channel configuration information sent by the network device, whether to allocate the resource to the data packet on the logical channel.

Abstract: A data processing method, including determining, by a second device, in response to a first device switching from the second device to a third device, data receiving status information of the first device, and reporting, by the second device, the data receiving status information of the first device, where the data receiving status information instructs a fourth device to send data to the first device according to the data receiving status information.

Abstract: When a PDCP entity over a UM DRB is re-established, or when a cell handover occurs and a PDCP entity over a UM DRB uses a key used before the handover, the PDCP entity determines a first SDU, where the first SDU is an SDU that is associated with a sequence number by the PDCP entity but whose corresponding data has not been transmitted through an air interface; and delivers a PDU corresponding to the first SDU to an RLC entity.

Abstract: A method includes sending, by an access network device, first indication information to a terminal device, where the first indication information indicates a last packet in one or more first-type packets or a first packet in one or more second-type packets, where the first-type packet is enciphered using a first cipher key, and the second-type packet is enciphered using a second cipher key.

Abstract: A measurement method includes sending, by a first device to a second device, a message including a first configuration, wherein the first configuration indicates that a first event triggers the second device to send a first measurement message. The first event includes at least a channel quality of a measurement object is less than a first threshold, the channel quality of the measurement object is lower than a channel quality of a serving cell of the second device, the channel quality of the measurement object is less than the first threshold, and the channel quality of the serving cell of the second device is greater than a second threshold, or the channel quality of the measurement object is lower than the channel quality of the serving cell of the second device and the channel quality of the serving cell of the second device is greater than the second threshold.