Abstract: A resource selection method, an apparatus, and a device, where the method includes determining, by first user equipment (UE), parameter information of a sensing window, where the parameter information includes at least one of a start time, a time span, or a quantity, sensing, by the first UE, the resource in the sensing window according to the parameter information of the sensing window, and selecting, by the first UE, a resource according to a sensing result.

Abstract: Embodiments of the present invention disclose a communication method and a communications apparatus. In the communication method, a network-side device determines a resource configuration policy. The network-side device determines an operation mode of a terminal based on the resource configuration policy; broadcasts information about a plurality of configured resource pools and the operation mode, so that the terminal performs sending based on the configured one or more resource pools; and determines, based on the operation mode, that the terminal sends information on one or more resource units of the plurality of resource pools. According to the communication method and the communications apparatus provided in the specific embodiments of the present invention, the one or more resource pools are configured for a plurality of carriers for inter-terminal communication, so that the terminal can send a message on the one or more resource pools of the plurality of carriers.

Abstract: A method of performing a random access procedure includes randomly selecting a backoff time from within a backoff window ranging from 0 to a specified multiple of a random access preamble unit, waiting until a time initialized with the backoff time expires, and retransmitting a random access preamble.

Abstract: First configuration information is configured for a second device by a first device. The first configuration information is used to indicate a first time-frequency resource allocated by the first device. The first time-frequency resource is different from a second time-frequency resource that is allocated by the first device to a third device in a same group. The first time-frequency resource comprises a third time-frequency resource and a fourth time-frequency resource. The third time-frequency resource is a time-frequency resource used when the first device receives a message sent by the second device. The fourth time-frequency resource is a time-frequency resource used when the first device sends a message to the second device. The third time-frequency resource is different from the fourth time-frequency resource. Control information that includes the first configuration information is sent by the first device.

Abstract: A method and an apparatus for obtaining installation information of a network access device. The network access device may be CPE. When a user installs the CPE, after the user uses a terminal device to send a request for obtaining installation information of the CPE to a network device, and to receive the installation information of the CPE that is fed back by the network device, the received installation information of the CPE can be displayed on a display interface.

Abstract: A self-contained subframe configuration method includes obtaining configuration information of a self-contained subframe of a current frequency band based on a subframe transmission direction of a neighboring frequency band. The self-contained subframe includes a downlink control (DLcontrol) field, a first transmission subframe, a second transmission subframe, a guard period (GP), and an uplink control (ULcontrol) field. The first transmission subframe or the second transmission subframe of the self-contained subframe is transmitted in the same subframe transmission direction used during subframe transmission on the neighboring frequency band. Alternatively, the first transmission subframe or the second transmission subframe of the self-contained subframe is transmitted in a guard period of the neighboring frequency band.

Abstract: A resource selection method includes monitoring, by a first terminal, a first subframe, where a quantity of the first subframes is less than or equal to a quantity of second subframes; receiving, by the first terminal, indication information in the first subframe; determining, by the first terminal, a first resource in the second subframe according to the indication information; and selecting, according to the first resource, a resource in the second subframe for the first terminal to send data. There may be one or more first subframes; the second subframe may be a candidate subframe, and there may be one or more candidate subframes. The indication information includes information that can indicate a resource reserved by a second terminal, that is, indication information that can indicate a resource excluded by the second terminal.

Abstract: This application discloses a signal transmission method and a related device. The method may include: sending, by a first terminal, a first message to a network device, where the first message is used to indicate a transmission mode used by the first terminal to transmit a signal; receiving a second message sent by the network device, where the second message is used to indicate a resource used by the first terminal to transmit the signal; and transmitting the signal on the resource. According to the foregoing solution, a terminal may transmit a signal by using different transmission modes and resources.

Abstract: A terminal synchronization method and a terminal relate to the communications field, where the terminal sends synchronization signals in a distributed manner by controlling a sequence for sending the synchronization signals such that terminals in a vehicle to vehicle communications system can have uniform timing. The method includes obtaining, by a terminal, a configurable transmission period for sending a first synchronization signal, and sending, by the terminal, the first synchronization signal based on the configurable transmission period.

Abstract: A data transmission method, an apparatus, and a communications device include sending, by a first device, first information using a first carrier, where the first information indicates that the first device uses N carriers in M carriers to send data, where N is an integer greater than or equal to 2, and N is less than or equal to M, sending, by the first device, the data using the N carriers.

Abstract: Embodiments of this application provide a transmission path switching method and apparatus. When a transmission path is switched, a currently used data transmission path is not directly switched from a first transmission path to a second transmission path after the second transmission path is configured, but after it is further determined that a first condition is met, the currently used data transmission path is switched from the first transmission path to the second transmission path, to avoid data interruption in a process of switching a data transmission path of an application from the first transmission path to the second transmission path. This improves use smoothness of the application.

Abstract: This application relates to the wireless communications field, and discloses a random access method and apparatus, to resolve a problem of how a terminal device selects an uplink to perform random access. The method includes: selecting, by a terminal device, a first uplink from at least two preconfigured uplinks to perform random access; and selecting, by the terminal device when random access performed by using the first uplink fails, a second uplink from the at least two uplinks to perform random access, where the at least two uplinks are communications links between the terminal device and a first network device, the first network device and the terminal device are located in a same cell, the first uplink is a normal uplink NUL, and the second uplink is a supplementary uplink SUL. In this way, the terminal device selects an uplink to perform random access.

Abstract: Embodiments of this application relate to the communications field, and provide a terminal synchronization method and a terminal. A terminal sends synchronization signals in a distributed manner by controlling a sequence for sending the synchronization signals, so that terminals in a vehicle to vehicle communications system can have uniform timing. The method includes: obtaining, by a terminal, a configurable transmission period for sending a first synchronization signal; and sending, by the terminal, the first synchronization signal based on the configurable transmission period.

Abstract: A transmission parameter configuration method includes a first device that determines a transmission parameter used for group communication, and sends information including the transmission parameter to a second device in a group through a broadcast message, where the first device is a management device of the group, and the transmission parameter includes a frequency domain resource or a demodulation reference signal (DMRS) pattern that is used for group communication of the group.

Abstract: A data transmission method, applied to a first terminal device, includes receiving a first message from a second terminal device, determining a first session parameter based on the first message, determining a first session based on the first session parameter, receiving first data from the second terminal device, and sending the first data to a network device using the first session. The first terminal device may determine, based on the first message from the second terminal device, the first session parameter that meets a service requirement of the second terminal device, determine, based on the first session parameter, the first session that meets the service requirement of the second terminal device, and forward data of the second terminal device to the network device using the first session.

Abstract: A communication method, a base station, a user equipment (UE), and a communications system. The method includes generating an uplink resource request message including identification information of a first UE, and sending, by the first UE, the uplink resource request message to a base station on a third time domain resource of a first subframe. The first subframe includes a first, second and third time domain resource, the first time domain resource of the first subframe is before the second time domain resource, the second time domain resource is before the third time domain resource, the first time domain resource is used to send first downlink control information, the second time domain resource is used to send downlink data, the first resource indication information indicates a first downlink resource used by base station to send the downlink data to a second UE.

Abstract: A control information processing method and system includes: receiving, by a first device, first control information sent by a network device; determining, by the first device based on first information, that the first control information is used to schedule a target device, where the target device is one of the first device and at least one second device. The first information is related to the first control information. When the target device is at least one second device, determining, by the first device, second control information based on resource information that is used for data transmission and that is included in the first control information, and sending the second control information to the target device, so that the target device transmits data based on the second control information. When the target device is the first device, transmitting, by the first device, data based on the first control information.

Abstract: A slot scheduling method and apparatus are provided. A determined slot includes a first slot, the first slot includes a first idle time, and a time interval between a start moment of the first idle time and a start moment of the first slot is less than or equal to a preset time interval threshold, or a time interval between a start moment of the first idle time and an end moment of at least one OFDM symbol that is in the first slot and that is used to transmit control signaling is less than or equal to a preset time interval threshold. No first service is scheduled in the first idle time, thereby providing a transmission opportunity for a second service. In addition, time-domain locations of uplink transmission and downlink transmission of the first service and the second service do not overlap.

Abstract: This application provides a physical downlink control channel processing method and a related device. In the method, a search space may be determined based on a first radio network temporary identifier, where the search space is a set of M candidate physical downlink control channels; and a target physical downlink control channel is detected from the search space based on a second radio network temporary identifier, where the first radio network temporary identifier is a radio network temporary identifier of a first device or a second device, the second radio network temporary identifier is the radio network temporary identifier of the second device, first downlink control information carried by the target physical downlink control channel is information that is scrambled by using the second radio network temporary identifier and that is used to schedule the second device, and the second device communicates with a network by using the first device.