Provided are methods and apparatus for performing communication in an unlicensed band. The method includes: detecting a channel occupation failure of an unlicensed band wireless resource for transmitting and receiving uplink data or downlink data; determining that channel access fails in the unlicensed band wireless resource if the channel occupation failure satisfies certain criteria; and transmitting upper layer signaling to a base station if channel access fails.

A method performed by a user equipment (UE) for wireless communication is provided. The method includes initiating a random access (RA)-based small data transmission (SDT) procedure while the UE is in a radio resource control (RRC) inactive state; starting a timer while the UE is in the RRC inactive state after initiating the RA-based SDT procedure; initiating an RA procedure; determining whether an RA problem associated with the RA procedure has occurred while the timer is running; and in response to determining that the RA problem of the RA procedure has occurred while the timer is running, transitioning from the RRC inactive state to an RRC idle state.

A method of a first user equipment (UE) to transmit information related to a conflict of a reserved resource in a wireless communication system comprises receiving, from a second UE, a first sidelink control information (SCI) related to a first reserved resource for a physical sidelink shared channel (PSSCH), receiving, from a third UE, a second SCI related to a second reserved resource for a PSSCH, determining a conflict between the first reserved resource and the second reserved resource, and transmitting, to the second UE or the third UE, information related to the conflict.

An apparatus and a method of processing collision between synchronization signal/physical broadcast channel block (SSB) transmission and periodic transmission, applied in a shared spectrum are provided. The method includes obtaining, by a terminal device, a first candidate SSB position within a discovery burst transmission (DRS) window and obtaining, by the terminal device, a first resource for the periodic channel or signal transmission, wherein when the first resource is overlapped with the first candidate SSB position, determining, by the terminal device, whether the first resource is available for the periodic channel or signal transmission. This can solve issues in the prior art, provide a technical solution of handling a possible collision between an SSB and the periodic channel or signal, provide a simple implementation, provide a good communication performance, and/or provide high reliability.

Disclosed relates to a method, device, and system for performing downlink transmission. Specifically, the disclosed relates to a method including when the downlink signal includes a physical downlink shared channel (PDSCH) and a channel in the specific cell is sensed to be idle for a first predefined interval, wherein the processor performs backoff after the second predefined time in order to perform the downlink transmission, and when the downlink transmission includes a Discovery Reference Signal (DRS) and the channel in the specific cell is sensed to be idle for a second predefined interval, performing the downlink transmission immediately after the second predefined interval, and a device and system therefor.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may determine an actual power delay profile (PDP) associated with a channel between the UE and a base station, wherein the actual PDP indicates an averaged power level of the channel over a period of time. The UE may determine whether a channel estimation mode switching event is satisfied. The UE may switch, based at least in part on the channel estimation mode switching event being satisfied, between a first channel estimation mode based at least in part on the actual PDP and a second channel estimation mode based at least in part on a template PDP. Numerous other aspects are described.

Various schemes pertaining to encoding and transmit power control for downsized trigger-based (TB) physical-layer protocol data unit (PPDU) transmissions in next-generation WLAN systems are described. A station (STA) receives a trigger frame indicating an allocated resource unit (RU) of a first size. The STA performs channel sensing responsive to receiving the trigger frame. In response to detecting at least one subchannel being busy from the channel sensing, the STA performs a downsized trigger-based (TB) transmission with a downsized RU or multi-RU (MRU) of a second size smaller than the first size by utilizing downsized RU or MRU allocation information while maintaining a value of each of one or more parameters unchanged in an encoding process to perform the downsized TB transmission.

A method and apparatus for consistent LBT failure detection and recovery in cell handover. The method is applicable to a terminal equipment and includes receiving a consistent LBT failure indication during cell handover, and suspending data transmission and/or reception with a network device and/or suspending consistent LBT failure detection and recovery during the cell handover.

A method and apparatus for accessing a NR cell in a mobile communication system are provided. Method for accessing a NR cell includes receiving in a first cell, by a terminal from a base station, a System Information Block1 (SIB1), determining, by the terminal, if the first cell is barred and performing by the terminal, if the cell is not barred, random access procedure based at least in part on a second pusch-TimeDomainAllocationList and a second ra-ContentionResolutionTimer.

A method of wireless communication includes identifying, by a first node configured for operation in a synchronous communication mode, a current synchronization boundary according to a common clock of the synchronous communication mode. The method further includes performing, by the first node, a common clock-triggered (CCT) listen before talk (LBT) procedure of a shared communication channel during a periodic quiet interval at the current synchronization boundary. The method further includes establishing, by the first node, in response to success of the CCT LBT procedure, a channel occupancy time (COT) configured to end at a subsequent synchronization boundary and transmitting, by the first node, data on the shared communication channel during the COT.