Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a base station, a system information block (SIB) that indicates a selected set of message repetition numbers from a plurality of sets of message repetition numbers. The UE may receive, from the base station, a bit field in a random access response (RAR) or downlink control information (DCI) that indicates a selected message repetition number from the selected set of message repetition numbers indicated in the SIB. The UE may transmit, to the base station, a message during a random access procedure based at least in part on the selected message repetition number. Numerous other aspects are described.

Embodiments of this disclosure relate to the communications field, and provide a repeated transmission method and an apparatus, to increase a probability of successful decoding of a user equipment. The method includes: performing, by a user equipment, first transmission of uplink data, and sending a first reference signal to a network device based on a first transmit power, where the first reference signal is used to demodulate the first transmission of the uplink data; and performing, by the user equipment, N.sup.th transmission of the uplink data, and sending a second reference signal to the network device based on a second transmit power, where N is an integer greater than or equal to 2, the second reference signal is used to demodulate the N.sup.th transmission of the uplink data, and the second transmit power is less than the first transmit power.

An operation method of a first terminal in a communication system is provided. The method includes transmitting first SCI to a second terminal, the first SCI including one or more information elements among information indicating time resource(s) for sidelink communication, information indicating frequency resource(s) for the sidelink communication, information indicating a periodicity of physical resources for the sidelink communication, and information indicating an MCS for the sidelink communication. Second SCI is transmitted to the second terminal, the second SCI including information for an HARQ feedback operation and information indicating an NDI. The method further includes performing the sidelink communication with the second terminal based on the first SCI and the second SCI associated with the first SCI.

A random access method, a base station, an UE and a device with a storage function are disclosed. The random access method includes: the base station receiving a first message transmitted by the UE, the first message including a preamble message and a signal message; decoding the preamble message and the signal message respectively; if the decoding of preamble message is succeeded, but the decoding of signal message fails, the base station transmits a second message to the UE, and storing the signal message of decoding failure, the second message configured to request the UE to retransmit the signal message; receiving the third message transmitted by the UE, the third message including the signal message; using a chase combine mechanism to decode the third message according to the stored signal message in the first message. The present disclosure save time and improve the efficiency of random access.

This disclosure describes a first slave device that transmits information to a second slave device indicating that a first data packet was improperly received from a master device, so that a corresponding data packet may be relayed from the second slave device to the first slave device. In an aspect, the second slave device may receive a first data packet followed by an indication that the first slave device improperly received the first data packet, where the second slave device is configured to relay the first data packet to the first slave device in response thereto. In another aspect, the second slave device may receive a request to listen for a separate data stream of the first slave device based on a first data packet being improperly received by the first slave device and transmit a second data packet of the separate data stream to the first slave device.

Certain aspects of the present disclosure provide techniques for cross-carrier retransmission. A method that may be performed by a user equipment (UE) includes monitoring for an initial transmission of data from a network on a first entity, generating a negative acknowledgement message indicating that decoding of the initial transmission of the data was unsuccessful, transmitting the negative acknowledgement message, and monitoring for a retransmission of the data on a second entity after the transmission of the negative acknowledgement message, the second entity being different than the first entity.

Provided are an eNodeB (eNB) and a user equipment (UE) in a wireless communication system supporting a machine type communication (MTC). The present invention comprises: receiving a first message including a UE-specific configuration on the basis of a common configuration for a plurality of UEs; and receiving a second message according to the UE-specific configuration, wherein the common configuration may include at least one of the number of times of repetition of the first message and a rate matching pattern of the first message.

A method for a wireless communications system is disclosed. In one example, user equipment (UE) maintains at least one serving beam, and uses a serving beam to perform an uplink (UL) transmission of data. The data is stored in an uplink hybrid automatic repeat request (UL HARQ) buffer. When there is a failure to track the serving beam, a beam recovery procedure is initialized. After successful completion of the beam recovery procedure, the UE retransmits the data stored in the UL HARQ buffer. The UE prevents the data from being flushed from the UL HARQ buffer when the failure to track the serving beam occurs, so that the data can be retransmitted.

Some of the present implementations provide a method for a user equipment (UE) for performing a random access (RA) procedure. The method receives, at the UE, an RA configuration and a reference signal received power (RSRP) threshold. The method then determines whether a detected RSRP exceeds the RSRP threshold once the RA procedure is initiated. If the detected RSRP exceeds the RSRP threshold, the method performs a two-step RA procedure.

A communication device, processing device or method constructs M RLC PDUs including M RLC SDUs, respectively, where M is larger than 1; submits, for a transmission opportunity, only L RLC PDUs for L RLC SDUs with lowest L SNs among the M RLC PDUs to a MAC layer, where L<M and the L RLC PDUs include a first RLC PDU having a poll to trigger status reporting at a receiving device; transmits the L RLC PDUs to the receiving device; constructs a second RLC PDU including a second RLC SDU having a highest SN among SNs of RLC SDUs submitted to the MAC layer, when the poll retransmission timer started upon submitting the first RLC PDU having the poll expires and no new RLC SDU or RLC SDU segment can be transmitted.