Abstract: In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a UE. In certain configurations, the UE establishes a connection supporting an extended reality (XR) application service with a base station. The UE reports, to the base station under a trigger condition, a buffer status report (BSR) to indicate a buffer size for data to be transmitted to the base station. The BSR includes information related to a corresponding BSR table. The UE receives a configuration instruction from the base station. The UE configures resources on the UE.

Abstract: In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a UE. In certain configurations, the UE determines whether a discarding mechanism is to be applied to a video stream. When the discarding mechanism is to be applied to the video stream, for each video frame of a plurality of frames of the video stream, the UE allocates data of the each video frame to corresponding data units, and assigns a priority level to each unit of the corresponding data units based on an attribute of the each video frame. The UE determines that a communication link for transmitting the plurality of video frames is congested. The UE discards data units of the plurality of video frames based on priority levels of the data units.

Abstract: In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a UE. In certain configurations, the UE establishes a connection supporting an extended reality (XR) application service with a base station. The UE reports, to the base station, a delay status report (DSR) to indicate a buffer size for data to be transmitted to the base station. The DSR includes timing information. The UE receives a configuration instruction from the base station. The UE configures resources on the UE according to the configuration instruction to transmit the data to the base station.

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: Various techniques pertaining to utilization of a lean protocol stack with respect to user equipment and network apparatus in mobile communications are described. An apparatus communicates with a network node of a wireless network by utilizing a lean protocol stack. In utilizing the lean protocol stack, the apparatus performs one or more of the following: (i) a split-stack operation; (ii) data concatenation; and (iii) uplink (UL) scheduling optimization.

Abstract: Various solutions for identifying support of a reduced capability in mobile communications are described. An apparatus, implementable in a user equipment (UE), receives from a network an indication of support of a reduced capability. The apparatus then communicates with the network using the reduced capability, including transmitting to the network an identifier that identifies the UE as a reduced-capability UE.

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: 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 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 handling overlapped transmission opportunities with respect to user equipment and network apparatus in mobile communications are described. An apparatus may receive configurations allocating a first transmission opportunity and a second opportunity. The apparatus may determine whether the first transmission opportunity and the second transmission opportunity are overlapped. The apparatus may determine a priority of at least one of the first transmission opportunity and the second transmission opportunity according to a predetermined rule in an event that the first transmission opportunity and the second transmission opportunity are overlapped. The apparatus may perform a transmission according to the priority.

Abstract: Apparatus and methods are provided for reliable multicast transmission with compact protocol stack. In one novel aspect, compact protocol stacks are configured for the UE and the base station handling both the PTM RB and the PTP RB. The compact protocol stack is either configured a compact RLC entity or a compact PDCP entity. The UE monitors a PTM LCH and a PTP LCH and sends feedback to the network with the PTP RB. The base station transmits MBS data packets in the PTM mode to the one or more subscriber UE, monitors feedback report from each subscriber UEs through corresponding PTP RB, and retransmits MBS data packets to one or more UEs through corresponding PTP RBs based on corresponding feedback reports. PTM-to-PTP and PTP-to-PTM mode switches are performed when triggering events are detected. The mode switch notification is sent to UEs via MAC CE or RLC control PDU.

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: Apparatus and methods are provided for reliable multicast transmission with uplink feedback. In one novel aspect, a unicast RB associated with the multicast RB is configured. In one embodiment, a single protocol stack is configured for the UE to receive MBS data packets from both the PTM RB and the PTP RB. The UE assembles data packets from the multicast RB and the unicast RB at the single UE protocol stack and provides uplink feedback for MBS data reception status through the PTP RB. The uplink feedback is provided by the UE RLC entity with RLC status report or by the UE PDCP entity with PDCP status report. The UE is configured with one LCH for the MBS and monitors a multicast LCH through a G-RNTI and a unicast LCH through a C-RNTI. Alternatively, the UE is configured with a multicast LCH and a unicast LCH.

Abstract: Various examples and schemes pertaining to simple Ethernet header compression are described. A first network node transmits a first packet with a full header to a second network node. The first network node determines whether a header compression context for the full header has been established by the second network node. In response to determining that the header compression context for the full header has been established by the second network node, the first network node transmits a second packet with a compressed header to the second network node. In response to determining that the header compression context for the full header has not been established by the second network node, the first network node transmits the second packet or a third packet with the full header to the second network node.

Abstract: A method of multiplexing logical channels (LCHs) in configured grants (CG) to enable faster transmission of high priority data in 5G New Radio-Unlicensed (NR-U) is proposed. Two options of imposing a CAPC-based restriction rule on multiplexing a low priority LCH with a high priority LCH are provided. In a first option, a threshold CAPC value is configured via RRC signaling. Data belonging to LCH having a priority lower than the CAPC threshold is not allowed to be multiplexed with data belonging to LCH having a priority higher than the CAPC threshold. In a second option, each CAPC has a flag indicating if the CPAC can have reduced priority via RRC signaling. If the flag is set for the CAPC, then data belonging to LCH assigned with the CAPC cannot be multiplexed with data belonging to lower priority LCHs.

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.