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.

A signal transmission method and a network device are provided. The method is applied to the network device and includes: performing LBT for a channel in an SSB transmission direction before a transmission of an SSB in an unlicensed band; and transmitting the SSB when the channel is detected as idle.

The present disclosure relates to a method and apparatus for transmitting and receiving data in a wireless communication system. A method of a base station for transmitting and receiving a synchronization signal includes performing listen-before-talk (LBT) on a channel of a terminal in an unlicensed band, and in case that the LBT succeeds within a window duration for transmitting a synchronization signal block (SSB), transmitting the SSB to the terminal, wherein the window duration includes at least one SSB burst length that is repeated in a specific period and has the specific period as a length of time, and the SSB is transmitted at a specific time within a first SSB burst length of the at least one SSB burst length.

A system and method for random access procedures in a non-terrestrial network. In some embodiments, the method includes calculating, by a user equipment (UE), a timing advance based on location information of the UE and on an ephemeris of a non-terrestrial network node. The method may further include randomly selecting a random value from a plurality of values, and sending, at a transmission time, by the UE, to the non-terrestrial network node, a random access (RA) message, which may include a signature. The transmission time may differ from a nominal transmission time by an amount based on the random value, the nominal transmission time being based on the timing advance, or the signature may differ from a nominal signature by a cyclic shift based on the random value.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a base station and while in a low-power mode, a reference signal, where the reference signal is not a cell-specific reference signal. Additionally, or alternatively, the UE may receive a signal including at least one parameter associated with the reference signal. Accordingly, the UE may initiate, with the base station, a random access procedure based at least in part on measurements of the reference signal. In some aspects, the UE may initiate the random access procedure by transmitting, to the base station, a random access preamble based at least in part on the at least one parameter. Numerous other aspects are provided.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment may receive a timing advance (TA) command indicating partial TA compensation, start a TA timer for partial TA compensation for full duplex based at least in part on receiving the TA command, and perform a synchronization procedure based at least in part on expiration of the TA timer for partial TA compensation for full duplex. Numerous other aspects are provided.

In a communications system which complies with LTE including a base station which transmits data by using an OFDM (Orthogonal Frequency Division Multiplexing) method as a downlink access method, and a mobile terminal, in a case in which an uplink scheduling request signal is transmitted by using an S-RACH when an Ack/Nack signal is being transmitted by using an Ack/Nack exclusive channel, the transmission of the Ack/Nack signal is stopped while the uplink scheduling request signal is transmitted.

Provided is a method of performing a random access procedure, the method including: selecting, from among a plurality of Synchronization Signal Blocks (SSBs), a first SSB that exceeds a threshold value of signal power; transmitting a contention-based random access preamble corresponding to the first SSB; receiving a first Random Access Response (RAR) corresponding to the contention-based random access preamble; obtaining a first Media Access Control Protocol Data Unit (MAC PDU) corresponding to a size of uplink (UL) resource allocation in the first RAR; transmitting a message3 (Msg3) including the first MAC PDU; determining, by transmitting the Msg3, whether contention is resolved; and when the contention is not resolved, performing a contention-free random access procedure.

According to some embodiments, a method for use in a user equipment (UE) of transmitting uplink data in unlicensed spectrum comprises receiving, from a network node, an uplink grant comprising an indication of one or more subframes to use for transmitting uplink data. Each subframe comprises a plurality of symbols. The method further comprises obtaining an indication of a listen-before-talk (LBT) type. The LBT type indicates a type of LBT procedure that the UE should perform before transmitting uplink data. The method further comprises determining, using the obtained LBT type, at least one of a starting symbol and a stopping symbol for transmitting uplink data, and transmitting uplink data according to at least one of the determined starting symbol and the determined stopping symbol.

Provided is a method of performing a random access procedure, the method including: selecting, from among a plurality of Synchronization Signal Blocks (SSBs), a first SSB that exceeds a threshold value of signal power; transmitting a contention-based random access preamble corresponding to the first SSB; receiving a first Random Access Response (RAR) corresponding to the contention-based random access preamble; obtaining a first Media Access Control Protocol Data Unit (MAC PDU) corresponding to a size of uplink (UL) resource allocation in the first RAR; transmitting a message3 (Msg3) including the first MAC PDU; determining, by transmitting the Msg3, whether contention is resolved; and when the contention is not resolved, performing a contention-free random access procedure.