Abstract: Various solutions for autonomous retransmission on configured grant with respect to user equipment and network apparatus in mobile communications are described. An apparatus may start a first timer and a second timer when a transmission is performed on a hybrid automatic repeat request (HARQ) process configured for a configured grant. The apparatus may perform an autonomous retransmission using the configured grant when the second timer is expired. The apparatus may cancel restart of the first timer when the autonomous retransmission is performed. The apparatus may restart the second timer when the autonomous retransmission is performed. The apparatus may stop the second timer when the first timer expires. The apparatus may stop the second timer at the activation of a type 2 configured grant.

Abstract: Solutions pertaining to spectrum sharing in coordination between a non-terrestrial network (NTN) and a terrestrial network (TN) are proposed. An apparatus implemented in a UE measures a signal strength of each of one or more TN cells and one or more NTN cells. The apparatus reports a result of the measuring to a TN. The apparatus also receives an indication from the TN configuring and activating a bandwidth part (BWP) that separates transmission by a base station of the TN from NTN downlink (DL) transmissions.

Abstract: Methods for selectively enabling and disabling UL HARQ retransmission in NTN communications and communication apparatus utilizing the same. A method for selectively enabling and disabling uplink Hybrid Automatic Repeat request (HARQ) retransmission in Non-Terrestrial Network (NTN) communications includes: determining a set of logical channels that are allowed to transmit or a set of MAC CEs that are allowed to be transmitted using one or more specific uplink (UL) HARQ processes. The one or more specific UL HARQ processes include one or more UL HARQ processes for which the UL retransmission has been disabled, or one or more UL HARQ processes for which the UL retransmission has been enabled.

Abstract: Low Earth Orbit (LEO) satellites orbit around the earth at a high speed (mobility), but over a predictable or deterministic orbit. In this invention, an efficient mechanism to include a list of multiple Tracking Area Codes (TAC List) in LEO-NTN is proposed for efficient tracking area update (TAU). Each cell broadcasts a TAC list corresponding to all the tracking areas it covers as it moves, dynamically. A UE selects a cell and is registered with a TA during initial registration and cell selection. As the satellite moves, the UE reselects another cell during cell reselection. The UE triggers a TAU only if its current TA does not match with any tracking area code of the TAC List broadcasted by the reselected cell. By using the concept of TAC list, it significantly reduces the TAU signaling overhead in LEO-NTN.

Abstract: A communication apparatus includes a transceiver and a processor. The transceiver is configured to transmit and receive wireless signal. The processor is coupled to the transceiver and configured to perform operations comprising: establishing, via the transceiver, a wireless connection with a network node of a non-terrestrial network (NTN); and transmitting, via the transceiver, a timing advance (TA) report to the network node. The processor is configured to perform auto-compensation of time delays in signaling and a TA value is indicated in the TA report.

Abstract: Various solutions for system information design for synchronization in non-terrestrial network (NTN) communications are described. An apparatus (e.g., a UE) receives synchronization information from a wireless network. Using the synchronization information, the apparatus maintains synchronization in performing NTN communications with the wireless network.

Abstract: Various solutions for system information design for synchronization in non-terrestrial network (NTN) communications are described. An apparatus (e.g., a UE) determines synchronization information with respect to an implicit time reference associated with a wireless network. Using the synchronization information, the apparatus maintains synchronization in performing NTN communications with the wireless network.

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 schemes pertaining to conditions on LBT impact on MAC counters in mobile communications involve a user equipment (UE) determining a status of a listen-before-talk (LBT) failure detection and recovery feature. Based on the status of the LBT failure detection and recovery feature (e.g., whether the LBT failure detection and recovery feature is configured or not configured), a preamble transmission counter in a random access (RA) procedure or a scheduling request (SR) counter in a SR procedure is conditionally incremented in the event of an LBT failure.

Abstract: Various solutions for autonomous retransmission on configured grant with respect to user equipment and network apparatus in mobile communications are described. An apparatus may start a first timer and a second timer when a transmission is performed on a hybrid automatic repeat request (HARQ) process configured for a configured grant. The apparatus may perform an autonomous retransmission using the configured grant when the second timer is expired. The apparatus may cancel restart of the first timer when the autonomous retransmission is performed. The apparatus may restart the second timer when the autonomous retransmission is performed. The apparatus may stop the second timer when the first timer expires. The apparatus may stop the second timer at the activation of a type 2 configured grant.

Abstract: Various examples and schemes pertaining to multiplexing, addressing and HARQ for MsgB in two-step RACH in mobile communications are described. An apparatus implemented in a user equipment (UE) transmits to a network node of a wireless network a first message containing a preamble index and data. In response, the apparatus receives from the network node a second message containing a random access response (RAR) and contention resolution information. The second message is addressed to either a cell radio network temporary identifier (C-RNTI) of the UE or a random access radio network temporary identifier (RA-RNTI).

Abstract: Various solutions for autonomous retransmission on configured grant with respect to user equipment and network apparatus in mobile communications are described. An apparatus may start a first timer and a second timer when a transmission is performed on a hybrid automatic repeat request (HARQ) process configured for a configured grant. The apparatus may perform an autonomous retransmission using the configured grant when the second timer is expired. The apparatus may cancel restart of the first timer when the autonomous retransmission is performed. The apparatus may restart the second timer when the autonomous retransmission is performed. The apparatus may stop the second timer when the first timer expires. The apparatus may stop the second timer at the activation of a type 2 configured grant.

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 schemes pertaining to conditions on LBT impact on MAC counters in mobile communications involve a user equipment (UE) determining a status of a listen-before-talk (LBT) failure detection and recovery feature. Based on the status of the LBT failure detection and recovery feature (e.g., whether the LBT failure detection and recovery feature is configured or not configured), a preamble transmission counter in a random access (RA) procedure or a scheduling request (SR) counter in a SR procedure is conditionally incremented in the event of an LBT failure.

Abstract: Various solutions for skipping uplink transmission with respect to user equipment and network apparatus in mobile communications are described. An apparatus may determine whether a padding buffer status report (BSR) is included in a protocol data unit (PDU). The apparatus may skip transmission of the PDU when the padding BSR is included in the PDU. The PDU may comprise a medium access control (MAC) PDU. The MAC PDU may comprise no MAC service data unit (SDU).

Abstract: Various solutions for retransmissions across different configured grant (CG) configurations with respect to user equipment and network apparatus in mobile communications are described. An apparatus may receive a first CG configuration and a second CG configuration. The apparatus may perform an initial transmission of a transport block (TB) on the first CG configuration. The apparatus may determine whether the TB is allowed to be retransmitted on the second CG configuration according to at least one restriction in addition to a condition of identical transport block size (TBS). The apparatus may perform a retransmission of the TB on the second CG configuration in an event that the TB is allowed to be retransmitted on the second CG configuration.

Abstract: Various solutions for handling packet data convergence protocol (PDCP) duplication with respect to user equipment and network apparatus in mobile communications are described. An apparatus may determine whether a PDCP entity is associated with two radio link control (RLC) entities. The apparatus may determine whether PDCP duplication is activated. The apparatus may select one of the two RLC entities to transmit a PDCP control protocol data unit (PDU) in an event that the PDCP entity is associated with the two RLC entities and the PDCP duplication is activated.

Abstract: Various solutions for handling packet data convergence protocol (PDCP) duplication with respect to user equipment and network apparatus in mobile communications are described. An apparatus may determine whether a PDCP entity is associated with two radio link control (RLC) entities. The apparatus may determine whether PDCP duplication is activated. The apparatus may select one of the two RLC entities to transmit a PDCP control protocol data unit (PDU) in an event that the PDCP entity is associated with the two RLC entities and the PDCP duplication is activated.

Abstract: Various solutions for detecting consistent listen before talk (LBT) failure with respect to user equipment and network apparatus in mobile communications are described. An apparatus may determine whether an LBT failure is detected. The apparatus may start a first timer in an event that the LBT failure is detected. The apparatus may increase an LBT counter. The apparatus may determine whether the LBT counter reaches a threshold value. The apparatus may determine a consistent LBT failure event in an event that the LBT counter reaches the threshold value.

Abstract: Various solutions for autonomous retransmission on configured grant with respect to user equipment and network apparatus in mobile communications are described. An apparatus may start a first timer and a second timer when a transmission is performed on a hybrid automatic repeat request (HARQ) process configured for a configured grant. The apparatus may perform an autonomous retransmission using the configured grant when the second timer is expired. The apparatus may cancel restart of the first timer when the autonomous retransmission is performed. The apparatus may restart the second timer when the autonomous retransmission is performed. The apparatus may stop the second timer when the first timer expires. The apparatus may stop the second timer at the activation of a type 2 configured grant.