Abstract: Various solutions for uplink synchronization in non-terrestrial network (NTN) communications are proposed. An apparatus implemented in a user equipment (UE) receives a system information block (SIB) of a target cell via a non-terrestrial (NT) network node of the NTN. The apparatus obtains an explicit epoch time from the SIB of the target cell. Then, the apparatus performs an uplink (UL) synchronization with the target cell through adjusting an uplink transmit time according to the explicit epoch time.

Abstract: Various solutions for physical random access channel (PRACH) timing advance operation and PRACH configurations with respect to user equipment and network apparatus are described. An apparatus may determine a propagation delay between the apparatus and a network node. The apparatus may determine a pre-compensation timing margin. The apparatus may perform a timing advance pre-compensation according to the propagation delay and the pre-compensation timing margin. The apparatus may transmit an uplink signal by applying the timing advance pre-compensation.

Abstract: Various solutions for random access channel (RACH) preamble design in non-terrestrial network (NTN) communications with respect to user equipment and network apparatus are described. An apparatus may initiate a RACH procedure. The apparatus may determine a fractional frequency offset pattern or a cover code across groups of preamble sequences. The apparatus may generate a RACH preamble signal according to at least one of the fractional frequency offset pattern and the cover code. The apparatus may transmit the RACH preamble signal to a network node.

Abstract: Various solutions for timing advance (TA) reporting by a user equipment (UE) in non-terrestrial network (NTN) communications are described. An apparatus (e.g., a UE), capable of auto-compensation of time delays in signaling, establishes a wireless connection with a network node of a wireless network. The apparatus then transmits a TA report to the network node. Based on the TA, the network can configure a UE-specific offset for UL scheduling.

Abstract: An apparatus aborts a transmission of a first message of a first type of traffic in a first slot or sub-slot without resuming the transmission in the first slot or sub-slot. The apparatus then stores a payload of the first message. The apparatus later retransmits the payload in full in a second slot or sub-slot that is subsequent the first slot or sub-slot.

Abstract: An apparatus aborts a transmission of a first message of a first type of traffic in a first slot or sub-slot without resuming the transmission in the first slot or sub-slot. The apparatus then stores a payload of the first message. The apparatus later retransmits the payload in full in a second slot or sub-slot that is subsequent the first slot or sub-slot.

Abstract: A method includes receiving a measurement configuration from a serving cell of a user equipment (UE) in a non-terrestrial network (NTN) providing mobile communication service based on satellites. The satellites can be low Earth orbiting (LEO) satellites, geostationary Earth orbiting (GEO) satellites, and the like. The measurement configuration indicates a first synchronization signal block (SSB) based measurement timing configuration (SMTC) and a second SMTC. The first SMTC specifies first SMTC windows aligning with SSB signals from the serving cell of the UE. The second SMTC specifies second SMTC windows aligning with SSB signals from a first neighbor cell of the UE. The serving cell is associated with a first flying object, and the first neighbor cell is associated with a second flying object. The UE performs a measurement based on the first SMTC corresponding to the serving cell and the second SMTC corresponding to the first neighbor cell.

Abstract: Various solutions for power consumption reduction with multi-link operation with respect to user equipment and network apparatus in mobile communications are described. An apparatus may establish a first link with a first network node. The apparatus may establish a second link with a second network node. The apparatus may receive a dormancy indication via a physical layer signaling from the first network node. The apparatus may transit a dormancy state of the second network node according to the dormancy indication.

Abstract: Various solutions for reporting hybrid automatic repeat request-acknowledgement (HARQ-ACK) information with respect to user equipment and network apparatus in mobile communications are described. An apparatus may receive a first downlink control information (DCI) format indicating a first resource of physical uplink control channel (PUCCH) transmission. The apparatus may receive a second DCI format indicating a second resource of PUCCH transmission. The apparatus may determine that the receiving of the second DCI format is not earlier than a timing threshold from the first resource. The apparatus may cancel multiplexing of hybrid automatic repeat request-acknowledgement (HARQ-ACK) information corresponding to the second DCI format in the PUCCH transmission.

Abstract: Various solutions for reducing power consumption with wake-up mechanism with respect to user equipment and network apparatus in mobile communications are described. An apparatus may receive a configuration to monitor a wake-up indication (WUI) on predetermined occasions. The apparatus may monitor the WUI according to the configuration. The apparatus may determine whether the WUI is received. The apparatus may monitor a physical downlink control channel (PDCCH) in an event that the WUI is received.

Abstract: Various solutions for channel quality information reporting under discontinuous reception (DRX) with respect to user equipment and network apparatus in mobile communications are described. An apparatus may receive a configuration from a network node to report channel quality information. The apparatus may monitor an indication mechanism while in a power saving mode. The apparatus may determine whether a DRX on duration is cancelled by the indication mechanism. The apparatus may transmit the channel quality information to the network node in an event that the DRX on duration is cancelled by the indication mechanism.

Abstract: Various solutions for timing advance (TA) reporting by a user equipment (UE) in non-terrestrial network (NTN) communications are described. An apparatus (e.g., a UE), capable of auto-compensation of time delays in signaling, establishes a wireless connection with a network node of a wireless network. The apparatus then transmits a TA report to the network node. Based on the TA, the network can configure a UE-specific offset for UL scheduling.

Abstract: Various solutions for reducing uplink overhead with respect to user equipment and network apparatus in mobile communications are described. An apparatus may monitor a downlink channel. The apparatus may determining whether downlink control information (DCI) is received on the downlink channel. The apparatus may skip a hybrid automatic repeat request-acknowledgement (HARQ-ACK) feedback transmission on an uplink channel in an event that no DCI is received on the downlink channel.

Abstract: Various solutions for timing and frequency synchronization in non-terrestrial network (NTN) communications with respect to user equipment and network nodes are described. An apparatus may receive a reference time signaled by a network node. The apparatus may measure a received time of a downlink message from the network node. The apparatus may estimate a propagation delay according to the reference time and the received time. The apparatus may perform a timing pre-compensation according to the propagation delay.

Abstract: Various solutions for reducing uplink overhead with respect to user equipment and network apparatus in mobile communications are described. An apparatus may monitor a downlink channel. The apparatus may determining whether downlink control information (DCI) is received on the downlink channel. The apparatus may skip a hybrid automatic repeat request-acknowledgement (HARQ-ACK) feedback transmission on an uplink channel in an event that no DCI is received on the downlink channel.

Abstract: Various solutions for frequency domain-resource allocation (FD-RA) when frequency hopping is enabled with respect to user equipment and network apparatus in mobile communications are described. An apparatus may determine whether frequency hopping is enabled. The apparatus may determine at least one of a first coarse step size corresponding to a start of an FD-RA and a second coarse step size corresponding to a length of the FD-RA in an event that the frequency hopping is enabled. The apparatus may determine allocated resources blocks (RBs) according to at least one of the first coarse step size and the second coarse step size. The apparatus may perform a transmission on the allocated RBs.

Abstract: Various solutions for random access channel (RACH) preamble design in non-terrestrial network (NTN) communications with respect to user equipment and network apparatus are described. An apparatus may initiate a RACH procedure. The apparatus may determine a fractional frequency offset pattern or a cover code across groups of preamble sequences. The apparatus may generate a RACH preamble signal according to at least one of the fractional frequency offset pattern and the cover code. The apparatus may transmit the RACH preamble signal to a network node.

Abstract: Various solutions for determining a modulation and coding scheme (MCS) table with respect to user equipment and network apparatus in mobile communications are described. An apparatus may receive an indication from a network node. The apparatus may determine an MCS table from a plurality of MCS tables for a high-reliability service according to the indication. The apparatus may use the MCS table in a channel for the high-reliability service.

Abstract: Various solutions for slot aggregation design in non-terrestrial network (NTN) communications with respect to user equipment and network apparatus in mobile communications are described. An apparatus may receive a demodulation reference signal (DMRS) time bundling configuration. The apparatus may determine a duration interval of the DMRS time bundling configuration. The apparatus may perform channel estimation cross slots based on the duration interval.

Abstract: An apparatus aborts a transmission of a first message of a first type of traffic in a first slot or sub-slot without resuming the transmission in the first slot or sub-slot. The apparatus then stores a payload of the first message. The apparatus later retransmits the payload in full in a second slot or sub-slot that is subsequent the first slot or sub-slot.