The technology of this application relates to a random access method, applied to the communication field. The method includes a terminal device sends, to a network device, a first message used to establish a wireless connection, the terminal device receives, a connection response sent by the network device, where the connection response includes information about a first polarization parameter, and when accessing the network device based on the connection response, the terminal device determines, based on the information about the first polarization parameter included in the connection response, whether the terminal device is qualified to access the network device. A dimension, namely, a polarization parameter, is introduced into a random access procedure, so that a preamble capacity is increased, a problem that the network device cannot identify a colliding terminal device is alleviated, and efficiency of establishing a communication connection between the terminal device and the network device is improved.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive configuration information indicating at least one of: a configuration for requesting repetition for an uplink shared channel transmitted after receiving a contention-free random access (CFRA) message, or a configuration for dropping one or more repetitions of the uplink shared channel. The UE may request the repetition for the uplink shared channel if the configuration information indicates the configuration for requesting repetition. The UE may transmit the uplink shared channel based at least in part on the configuration information. Numerous other aspects are described.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive first information indicating a first set of parameters associated with repetition of a second random access message (RAM) associated with a random access channel (RACH) procedure. The UE may transmit, using the first set of parameters, an initial RAM in association with the RACH procedure. Numerous other aspects are described.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a base station may extract, from a neighboring base station with cell coverage that overlaps cell coverage of the base station, information associated with user equipment (UE) transmission of MsgA messages. The base station may select, based at least in part on the information, a physical uplink shared channel (PUSCH) resource to allocate to a UE for transmission of a MsgA message. The base station may transmit, to the UE, an allocation of the PUSCH resource. Numerous other aspects are described.

A method and a user equipment (UE) for timing alignment is provided. The method includes maintaining a Timing Advance (TA) value as a first TA value; receiving, from a Base Station (BS), a TA command during a Random Access (RA) procedure; applying the TA command to set the TA value to a second TA value included in the TA command in a case that a first timing alignment timer is not running; determining whether a contention resolution for the RA procedure is successful; and when the contention resolution is not successful, setting the TA value to the first TA value in a case that a Configured Grant-based Small Data Transmission (CG-SDT) procedure is ongoing.

Methods, systems, and apparatuses are provided for listen-before-talk (LBT) mode for random access response (RAR) in a wireless communication system so that RAR indication of channel access type and cyclic prefix (CP) extension can be more efficient. A method of a User Equipment (UE) can comprise initiating a random access procedure, receiving a RAR, wherein the RAR comprises a channel access type indication, and determining whether to perform LBT for a Msg3 based on the channel access type indication in RAR.

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.

An initial access method of an integrated access and backhaul (IAB) node in a wireless communication system and an apparatus using the method are provided. The method includes: receiving, from a parent node, a synchronization signal block (SSB) and system information; and performing a random access procedure with the parent node on the basis of the SSB and the system information, wherein the SSB and the system information are received through a resource allocated to an access link of the parent node, and the random access step is performed through a resource allocated to the backhaul link of the parent node, and the random access step is performed using resources determined differently depending on whether the TAB node is a relay node or a terminal.

Provided are a method of adjusting uplink timing in a wireless communication system and an apparatus therefor. Specifically, a method for a user equipment to adjust uplink timing in a wireless communication system includes transmitting, to a base station, an uplink signal, receiving, from the base station, a timing advance (TA) command configured based on the uplink signal, and performing uplink transmission to the base station by applying a timing advance (TA) indicated by the TA command. The TA command may be interpreted based on subcarrier spacing of at least one frequency resource region to which the TA is to be applied.

Methods, systems, and devices for wireless communications are described. In some systems, a user equipment (UE) may perform a random access channel (RACH) procedure with a base station. The UE may receive a message configuring a random access occasion and a PUSCH occasion. The UE may transmit a random access preamble according to the random access occasion scheduled in the message. The UE may also transmit a repetition of a physical uplink shared channel (PUSCH) data of the message corresponding to the random access occasion in each uplink transmission time interval for a defined number of uplink transmission time intervals that occur after the random access occasion.