Abstract: In an example, a User Equipment (UE) receives a message associated with Physical Downlink Shared Channel (PDSCH) parameter configuration. The message includes a first parameter indicating a first list of entries associated with time resource allocation for multiple PDSCHs, a second parameter indicating reception of multiple repetitions for a single PDSCH, and a third parameter indicating a second list of entries associated with time resource allocation. Each entry in the second list indicates a single time resource allocation. If the UE receives a Downlink Control Information (DCI) indicative of a first entry in the first list, the UE receives a plurality of PDSCHs based on a plurality of time resource allocations indicated by the first entry. A first repetition number for the plurality of PDSCHs is determined to be one.

Abstract: A method and apparatus are disclosed from the perspective of an initiating UE (User Equipment) for establishing a one-to-one sidelink communication with a target UE. In one embodiment, the method includes transmitting a first PC5 signalling used for establishing the one-to-one sidelink communication, wherein the first PC5 signalling includes an identity of the target UE and an identity of a V2X (Vehicle-to-Everything) service.

Abstract: A method and apparatus are disclosed, from the perspective of the UE, for performing random access procedure. In one embodiment, the method includes the UE receiving a message from a network. The message includes a TTI information of Msg3. In addition, the method includes the UE transmitting a preamble to the network. The method also includes the UE receiving a Msg2 from the network for responding the preamble. The method further includes the UE performing a Msg3 transmission to the network according to the TTI information of Msg3.

Abstract: A method and apparatus are disclosed from the perspective of an User Equipment (UE). In one embodiment, the method includes the UE performing sensing on a second direction or beam. The method also includes the UE performing a sidelink transmission on a resource on a first direction or beam, wherein the resource is selected based on at least sensing result of the second direction or beam.

Abstract: A method and apparatus are disclosed from the perspective of a first device. In one embodiment, the method includes the first device receiving a configuration, from a network node, of a first sidelink resource pool without any Physical Sidelink Feedback Channel (PSFCH) resource. The method further includes the first device receiving a first sidelink grant transmitted, configured, or scheduled by the network node, wherein the first sidelink grant schedules or indicates at least a first sidelink resource in the first sidelink resource pool. Furthermore, the method includes the first device expecting or considering that the first sidelink grant provides no Physical Uplink Control Channel (PUCCH) resource for reporting Sidelink (SL) Hybrid Automatic Repeat Request (HARD) feedback.

Abstract: Control structures and techniques for transmission time interval (TTI) shortening in wireless communication systems are provided. Exemplary techniques can comprise establishing a UE device connection to a base station having a first TTI, wherein the UE device is configured to employ TTI shortening and has a second TTI different from the first TTI and monitoring a first short physical downlink control channel (PDCCH) region for a scheduled downlink (DL) transmission via the second TTI, wherein a time distribution associated with multiple second TTIs within the first TTI is determined based on a control format indicator (CFI) value indicated via the first TTI.

Abstract: A method and apparatus are disclosed from the perspective of a User Equipment (UE) for the UE to request sidelink resources for an one-to-one V2X (Vehicle-to-Everything) sidelink communication, wherein the UE supports both LTE (Long Term Evolution) RAT (Radio Access Technology) and NR (New Radio) RAT. In one embodiment, the method includes the UE initiating a one-to-one V2X sidelink communication. The method further includes the UE transmitting a RRC (Radio Resource Control) message to a network node to request sidelink resources from NR RAT for the one-to-one V2X sidelink communication and not transmitting any RRC message to the network node to request sidelink resources from LTE RAT for the one-to-one V2X sidelink communication.

Abstract: A method and apparatus are disclosed from the perspective of a first device to determine sidelink feedback resource associated with sidelink communication. In one embodiment, the method includes the first device receiving an identifier from an upper layer of the first device. The method also includes the first device receiving a sidelink transmission from a second device. The method further includes the first device determining a sidelink feedback resource associated with the sidelink transmission at least based on the identifier and a source ID (Identity) associated with the sidelink transmission. In addition, the method includes the first device using the sidelink feedback resource to transmit a feedback in response to the sidelink transmission to the second device.

Abstract: Methods and apparatuses for handling device-to-device feedback transmission in a wireless communication system are disclosed herein. In one method, a first device receives a configuration for operating in a network scheduling mode for acquiring sidelink resources. The first device receives a sidelink control information with a report request from a second device. The first device triggers or is triggered to transmit a report to the second device in response to the report request. If the first device has no available sidelink resource for transmitting the report, the first device triggers a scheduling request. The first device transmits a signaling of the scheduling request to the network. The first device receives a sidelink grant from the network. The first device utilizes sidelink resource(s) indicated by the sidelink grant to transmit the report to the second device.

Abstract: A method and apparatus are disclosed from the perspective of a device to perform sidelink communication. In one embodiment, the method includes the device receiving a sidelink grant from a network node, wherein the sidelink grant schedules or assigns multiple sidelink resources. The method further includes the device generating a data packet comprising or multiplexing sidelink data from Sidelink (SL) logical channel(s) with SL Hybrid Automatic Request (HARQ) feedback enabled. The method further includes the device performing two sidelink transmissions for the data packet on two adjacent, neighbor, or consecutive sidelink resources among the multiple sidelink resources if a time gap of the two adjacent, neighbor, or consecutive sidelink resources is larger than or equal to a minimum time gap.

Abstract: A method and apparatus are disclosed, from the perspective of the UE, for performing random access procedure. In one embodiment, the method includes the UE receiving a message from a network. The message includes a TTI information of Msg3. In addition, the method includes the UE transmitting a preamble to the network. The method also includes the UE receiving a Msg2 from the network for responding the preamble. The method further includes the UE performing a Msg3 transmission to the network according to the TTI information of Msg3.

Abstract: A method and apparatus are disclosed from the perspective of a first device. In one embodiment, the method includes the first device receiving a configuration, from a network node, of a first sidelink resource pool without any Physical Sidelink Feedback Channel (PSFCH) resource. The method further includes the first device receiving a first sidelink grant transmitted, configured, or scheduled by the network node, wherein the first sidelink grant schedules or indicates at least a first sidelink resource in the first sidelink resource pool. Furthermore, the method includes the first device expecting or considering that the first sidelink grant provides no Physical Uplink Control Channel (PUCCH) resource for reporting Sidelink (SL) Hybrid Automatic Repeat Request (HARQ) feedback.

Abstract: Control structures and techniques for transmission time interval (TTI) shortening in wireless communication systems are provided. Exemplary techniques can comprise establishing a UE device connection to a base station having a first TTI, wherein the UE device is configured to employ TTI shortening and has a second TTI different from the first TTI and monitoring a first short physical downlink control channel (PDCCH) region for a scheduled downlink (DL) transmission via the second TTI, wherein a time distribution associated with multiple second TTIs within the first TTI is determined based on a control format indicator (CFI) value indicated via the first TTI.

Abstract: A method and apparatus are disclosed from the perspective of a transmitting device. In one embodiment, the method includes being configured or allocated with an identity, wherein the identity comprises a first part of the identity and a second part of the identity. The method also includes the transmitting device generating a data packet for sidelink transmission, wherein the data packet includes the second part of the identity. Furthermore, the method includes transmitting device generating a control information associated with the data packet, wherein the control information includes the first part of the identity. The method further includes the transmitting device transmits the control information and the data packet.

Abstract: A method and apparatus are disclosed from the perspective of a communication device. In one embodiment, the method includes the device being configured with a plurality of resource pools by a base station for a cell. The method further includes the device receiving a grant from the base station, wherein the grant indicates a resource associated with a resource pool of the plurality of resource pools through a resource pool index in the grant. The method also includes the device using the resource to perform a transmission on a device-to-device interface.

Abstract: A method and apparatus are disclosed from the perspective of a transmitting device. In one embodiment, the method includes being configured or allocated with an identity, wherein the identity comprises a first part of the identity and a second part of the identity. The method also includes the transmitting device generating a data packet for sidelink transmission, wherein the data packet includes the second part of the identity. Furthermore, the method includes transmitting device generating a control information associated with the data packet, wherein the control information includes the first part of the identity. The method further includes the transmitting device transmits the control information and the data packet.

Abstract: A method and apparatus are disclosed from the perspective of a device to perform sidelink communication. In one embodiment, the method includes the device receiving a sidelink grant from a network node, wherein the sidelink grant schedules or assigns multiple sidelink resources. The method further includes the device generating a data packet comprising or multiplexing sidelink data from Sidelink (SL) logical channel(s) with SL Hybrid Automatic Request (HARD) feedback enabled. The method further includes the device performing two sidelink transmissions for the data packet on two adjacent, neighbor, or consecutive sidelink resources among the multiple sidelink resources if a time gap of the two adjacent, neighbor, or consecutive sidelink resources is larger than or equal to a minimum time gap.

Abstract: A method and apparatus are disclosed. In an example from the perspective of a User Equipment (UE) configured with bundled transmission, the UE initializes a configured uplink grant. The UE performs a plurality of transmissions within a bundle of a Medium Access Control Protocol Data Unit (MAC PDU) using the configured uplink grant. The UE stops a Discontinuous Reception (DRX) timer in response to a first transmission of the plurality of transmissions, wherein the DRX timer is not stopped in response to one or more second transmissions of the plurality of transmissions. When the DRX timer is running, the UE monitors a downlink control channel for an uplink grant for retransmission.

Abstract: A method and device are disclosed from the perspective of a first remote User Equipment (UE). In one embodiment, the method includes the first remote UE establishing a first Sidelink (SL) Data Radio Bearer (DRB) for transmission to a second remote UE via a relay UE, wherein the first SL DRB is identified by a Radio Bearer (RB) Identity (ID). The method further includes the first remote UE ciphering a sidelink packet to be sent to the second remote UE on the first SL DRB based on at least the RB ID.

Abstract: A method and apparatus are disclosed from the perspective of a UE, wherein the UE is allocated with multiple SR configurations by a network node. In one embodiment, the method includes the UE triggering a MAC control element if a timer expires. The method also includes the UE triggering a SR for the MAC control element. The method also includes the UE transmitting the SR based on a first SR configuration of the multiple SR configurations, wherein the first SR configuration is associated with a highest priority logical channel having data available for transmission when the MAC control element is triggered.