The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. A channel access method of a user equipment (UE) transmitting sidelink information in an unlicensed band is provided. The method may include transmitting sidelink control information including at least one piece of a transmission type information of hybrid automatic repeat request (HARQ)-acknowledgement (ACK) feedback for data transmitted in a reference duration, adjusting a contention duration, based on the HARQ-ACK feedback for the data transmitted in the reference duration and the transmission type information of the HARQ-ACK feedback for the data transmitted in the reference duration, and performing channel access, based on the adjusted contention duration.

Various examples and schemes pertaining to uplink (UL) transmission timing for non-terrestrial networking (NTN) are described. An apparatus receives, from a network, downlink control information (DCI) indicating an NTN offset for a scheduling delay. Accordingly, the apparatus performs one or more UL transmissions to a satellite with the scheduling delay which accounts for the NTN offset.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive a first transmission on a first beam of a set of beams in a first time period of a first transmission duration. The UE may identify a second beam of the set of beams in a second time period of the first transmission duration. The UE may transmit an indication of the identified second beam of the set of beams for an uplink transmission and/or a downlink transmission in a second transmission duration. Numerous other aspects are provided.

A self-contained operation using a time-unit configuration taking into consideration HARQ processes is performed. In base station, transmission section transmits a downlink signal in a downlink transmission region in a time unit composed of the downlink transmission region, an uplink transmission region, and a gap interval that is a switching point from the downlink transmission region to the uplink transmission region; and reception section receives an uplink signal in the uplink transmission region in the time unit. Each time unit includes the downlink transmission region and the uplink transmission region for each of HARQ processes.

Devices and systems of sensing, resource selection and control signaling for feedback-less and feedback-based NR-V2X sidelink communication are described. Resource reservation and selection for sidelink retransmissions based on HARQ feedback are described for unicast, groupcast, and broadcast blind retransmissions. After exchanging HARQ feedback capability information for different types of communications, a HARQ-dependent or HARQ-independent resource selection occurs. Look-ahead and/or chain-based resource selection and reservation signaling is used, in which a single resource or some or all of the resources selected are signaled as reserved. Further resource selection of a single additional resource may occur after an initial resource selection. The resource selection for retransmissions may be adapted using a RSRP or distance threshold.

In an example, a second UE receives a first SCI and a second SCI from a first UE in a first slot. A groupcast sidelink transmission is scheduled by the first SCI and the second SCI. The second SCI indicates a location indication, associated with a location of the first UE, and a communication range. A PSFCH resource is determined based upon the first SCI. The second UE doesn't transmit a NACK indication on the PSFCH resource if location information of the second UE is available, the groupcast sidelink transmission isn't successfully decoded, and the second UE is outside the communication range. The second UE transmits the NACK indication on the PSFCH resource if the location information isn't available and the groupcast sidelink transmission isn't successfully decoded, or if the location information is available, the groupcast sidelink transmission isn't successfully decoded, and the second UE is within the communication range.

A method for performing wireless communication by a first device and a device for supporting same are provided. The method may include receiving, from a second device, a physical sidelink control channel (PSCCH) including a first sidelink control information (SCI) for scheduling a physical sidelink shared channel (PSSCH); receiving, from the second device, the PSSCH including a second SCI; and transmitting, to the second device, a hybrid automatic repeat request (HARQ) feedback through a physical sidelink feedback channel (PSFCH) in response to the PSSCH based on a format of the second SCI.

A method performed by a UE for implementing a random access procedure is provided. The method transmits a MSGA, monitoring an MSGB-RNTI within an MSGB time window starting from an earliest symbol of an earliest PDCCH occasion after the MSGA transmission. The method receives the MSGB in a first slot. The MSGB includes a success RAR that contains a HARQ Feedback Timing Indicator, a Physical Uplink Control Channel (PUCCH) Resource Indicator, and a UE Contention Resolution Identity. The method determines, by a MAC entity of the UE, to instruct a lower layer to transmit a HARQ feedback in a second slot in response to the reception of the success RAR. The method delivers, by the MAC entity, the HARQ Feedback Timing Indicator and the PUCCH Resource Indicator to the lower layer, and performs, by the lower layer, a HARQ feedback delivery on an uplink (UL) resource.

A communication scheme and a system of converging an IoT technology and a 5.sup.th generation (5G) communication system for supporting a higher data transfer rate beyond a 4.sup.th generation (4G) system are provided. The communication scheme includes intelligent services (e.g. smart home, smart building, smart city, smart car or connected car, health care, digital education, retail business, and security and safety-related services), based on a 5G communication technology and an IoT-related technology. A method performed by a terminal in a communication system is provided. The method includes receiving, from a base station, a semi-persistent scheduling (SPS) configuration including an SPS configuration index; identifying at least one physical downlink shared channel (PDSCH) corresponding to the SPS configuration; identifying a PDSCH with a lowest SPS configuration index in case that the at least one PDSCH corresponding to the SPS configuration is overlapped in time in a slot; determining a PDSCH for data transmission based on excluding a PDSCH that is overlapped with the PDSCH with the lowest SPS configuration index from the at least one PDSCH; and receiving, from the base station, data based on the determined PDSCH, wherein the at least one PDSCH is not overlapped with a symbol indicated as an uplink in the slot.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive physical-layer control information indicating to activate or deactivate a secondary cell; and activate or deactivate the secondary cell within a time period in accordance with the physical-layer control information, wherein the time period is based at least in part on a set of factors and based at least in part on the secondary cell being activated or deactivated by the physical-layer control information. Numerous other aspects are provided.