Abstract: This application discloses communications methods, apparatuses, and systems. In one implementation, a method includes: performing a function of a control-plane protocol layer, wherein the control-plane protocol layer comprises a first protocol layer of the network node corresponding to a first protocol layer of a relay node, the first protocol layer is on an interface between the network node and the relay node, and the network node is a donor base station or a centralized unit of a donor base station; and sending, from the first protocol layer of the network node, a first message to the first protocol layer of the relay node, wherein the first protocol layer of the network node and the first protocol layer of the relay node are F1 application protocol layers, and the first message is a F1AP message that comprises one or more of context management information of a terminal device served by the relay node or a radio resource control message of the terminal device.

Abstract: A user equipment (UE), the UE including: a controller configured to control to trigger a Buffer Status Report (BSR) if an allocated uplink resource for a Transmission Time Interval (TTI) is capable of accommodating a Sidelink Buffer Status Report (BSR) Medium Access Control (MAC) Control Element (CE) containing a buffer status for at least one Sidelink Destination and its corresponding MAC subheader; and a transmitter configured to transmit the BSR, wherein, the controller controls to cancel all triggered Sidelink BSRs if no side-link data available for transmission exists.

Abstract: A method and an apparatus for configuring transmission time interval (TTI), including a processor configured to execute instructions to: transmit to a user equipment (UE) configuration information about data radio bearers (DRBs), the configuration information about DRBs indicating TTI length to which each DRB configured by the eNB for the UE is applicable, wherein the DRBs are configured by radio resource control (RRC), and notify a target eNB of the TTI length to which each DRB of the UE is applicable when the UE needs to be handed over.

Abstract: A signal transmission method, including configuring, by a first terminal, a first resource, where the first resource comprises at least one of at least one low-frequency resource or at least one low-frequency resource pool, and receiving, by the first terminal, a beam failure recovery request from a second terminal on a low-frequency resource in the first resource, where the beam failure recovery request requests beam failure recovery.

Abstract: A timer control method includes a receiving device that performs re-establishment or data recovery on a Packet Data Convergence Protocol (PDCP) layer of the receiving device. The PDCP layer stops the running of a reordering timer of the PDCP layer when the reordering timer is in a running state, where the reordering timer enables the PDCP layer to wait to receive a lost data packet. Because the reordering timer is stopped from running rather than expires, the PDCP layer does not update a value of RX_DELIV.

Abstract: This application provides a data processing method and apparatus, and a computer storage medium. When a PDCP entity over a UM DRB is re-established, or when a cell handover occurs and the 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. Data corresponding to the first SDU is redelivered, to avoid a data packet loss caused by preprocessing of the PDCP entity.

Abstract: An indication method, including receiving, by first user equipment, a first message sent by second user equipment, where the first message includes information indicating that the second user equipment supports an evolved user equipment-to-network relay function, and receiving, by the first user equipment, a second message sent by a network device, where the second message includes information indicating that the network device supports an evolved user equipment-to-network relay, or the second message includes information indicating that a cell in which the network device sends the second message supports an evolved user equipment-to-network relay.

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 scheduling request (SR) configuration method and sending method, and a corresponding apparatus are provided, to resolve a prior-art problem of a scheduling request configuration method and sending method, and a corresponding apparatus. The scheduling request configuration method includes: receiving, by a user equipment (UE), control signaling sent by a network device, where the control signaling is used to configure, for the UE, an SR configuration associated with at least one logical channel and at least two SR resource configurations associated with the SR configuration, and the SR resource configurations indicate physical resources used to signal an SR associated with the at least one logical channel; and signaling, by the UE based on a physical resource indicated by one of the at least two SR resource configurations, an SR associated with one of the at least one logical channel.

Abstract: A relay selection method and apparatus and a system. The method includes: relay equipment broadcasts relay discovery information, the relay discovery information including identifier information (a relay UE ID) of the relay equipment and identifier information (a cell ID) of a serving cell of the relay equipment, so that remote terminal receiving the relay discovery information selects relay equipment according to the relay discovery information or transmits relay information of discovered relay equipment to an eNB, thus the eNB may select relay equipment for the remote terminal. With certain embodiments, the serving cell may learn a cell where a relay to which the terminal accesses is located, so as to perform configuration for the terminal or perform path switching of downlink data.

Abstract: A random access method and device. The method includes receiving, by user equipment, a radio resource control (RRC) connection reconfiguration message from a first network device, the RRC connection reconfiguration message indicating a primary serving cell of the second network device for a user equipment, an active uplink bandwidth part (BWP) in the primary serving cell, and an active downlink BWP in the primary serving cell, the RRC connection reconfiguration message includes an uplink BWP identifier indicating the active uplink BWP and a downlink BWP identifier indicating the active downlink BWP, the uplink BWP identifier corresponds to the active uplink BWP, the downlink BWP identifier corresponds to the active downlink BWP, and initiating, by the user equipment, a random access procedure to the second network device on the active uplink BWP and the active downlink BWP.

Abstract: Embodiments of this application provide a cell selection method and an apparatus, and relate to the communications field. A terminal may determine a first measurement frequency and a 5G anchor cell at the first measurement frequency based on prior historical information. The terminal may shorten evaluation duration corresponding to a 5G anchor cell that meets a preferred condition at a first measurement frequency, so as to improve a probability that the terminal camps on the 5G anchor cell.

Abstract: A data link quality-based offloading method in dual connectivity includes determining a quality of a bearer link on a user equipment UE side by determining and setting, determining a quality of a radio link by parameters or conditions such as timing advance (TA) timeout, a bit error rate, a signal strength or a signal amplitude, a threshold of continuous scheduling request (SR) sending, a radio link control (RLC) sliding window, a T310 timer, and a triggering of a beam failure recovery process, selecting, based on a determining result, a manner such as a packet replication or selecting a link, and transmitting data through two links.

Abstract: A discontinuous reception (DRX) parameter configuration method includes a first communication apparatus that sends data to a second communication apparatus on a sidelink based on a DRX parameter. The second communication apparatus determines an active time and a sleep period of the second communication apparatus based on the DRX parameter, and receives the data in the active time.

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: This application provides a base station switching method and an apparatus. The method includes: A terminal sends one piece of binding signaling that carries SIM card binding information to a source base station; the terminal switches a plurality of SIM cards from being connected to the source base station to being connected to the target base station; and the terminal sends radio resource control reconfiguration complete information to the target base station, where the radio resource control reconfiguration complete information includes information about the plurality of SIM cards that complete the switching operation.

Abstract: A timer processing method includes: receiving, by a terminal device, a first message sent by a network device, and starting or restarting a timer based on a scrambling identifier of the first message, wherein the timer is a timer used by the terminal device to switch from an active downlink BWP to a default downlink BWP, or is a timer used by the terminal device to activate a default downlink BWP and deactivate an active downlink BWP; or if an active BWP pair of the terminal device is not a default BWP pair, starting or restarting, by the terminal device, a timer based on a scrambling identifier of the first message, wherein the timer is a timer used by the terminal device to switch from the active BWP pair to the default BWP pair, or is a timer used by the terminal device to activate the default BWP pair.

Abstract: This application provides a sidelink communication method. The method includes: A first terminal device determines one or more pieces of first configuration information, where the one or more pieces of first configuration information correspond to one or more sidelinks, each piece of the first configuration information is used to configure a discontinuous reception DRX related parameter of a corresponding sidelink, and the first terminal device is a sending device or a receiving device on the one or more sidelinks. The first terminal device maintains, based on each piece of the first configuration information, a status of the discontinuous reception DRX corresponding to each piece of the first configuration information.

Abstract: Embodiments of this application provide a method and a communications apparatus for hybrid automatic repeat request processing, and relate to the field of communications technologies, to help reduce the possibility that an exception occurs due to the introduction of a HARQ feedback mechanism in sidelink communication. The method includes: A first terminal device receives first sidelink grant information, a first HARQ process identifier (ID), and first indication information from a network device. If the first indication information indicates retransmission and a transport block corresponding to a first HARQ process has been successfully sent, the first terminal device ignores the first sidelink grant information.

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.