Aspects of the disclosure relate to sidelink discontinuous reception (DRX) procedures for blind sidelink retransmissions. A first device may obtain a set of sidelink communication parameters that are associated with a second device. Based at least in part on the set of sidelink communication parameters, the first device may transmit to the second device a sidelink blind retransmission configuration. This configuration may include enablement of sidelink blind retransmission and/or establishment of a number of sidelink blind retransmissions. Other aspects, examples, and features are also claimed and described.

Aspects described herein relate to sidelink transmissions. In an example, a first user equipment (UE) may receive, from a network entity, a first sidelink grant for a transmission between the first UE and a second UE; communicate the transmission according to the first sidelink grant to the second UE; determine initiation of a sidelink round trip timer subsequent to communicating the transmission to the second UE; and initiate an inactive mode for the first UE based on a second grant not being received from the network entity before completion of a duration of a sidelink retransmission timer that was initiated upon completion of a duration of the sidelink round trip timer, the first UE being configured out of an ON duration of a discontinuous reception (DRX) cycle, and an inactivity timer expiring before completion of the duration of the sidelink retransmission timer.

According to one embodiment of the present disclosure, provided is a method by which a first apparatus performs sidelink communication. In one example, provided is a method by which the first device saves power for sidelink communication in NR V2X.

A method in a UE comprises monitoring a downlink control channel during a duration of at least a first timer, and receiving an indication of a downlink or uplink transmission for the UE. The method comprises after receiving the indication of the downlink or uplink transmission for the UE, stopping monitoring the first timer, wherein after the first timer is stopped the UE does not need to monitor the downlink control channel. The method comprises performing an uplink transmission associated with the indicated downlink or uplink transmission for the UE. The method comprises starting a second timer after receiving the indication for the downlink or uplink transmission for the UE, the duration of the second timer comprising an offset period, and, when the second timer expires, starting a third timer. The UE monitors the downlink control channel for the duration of the third timer.

Apparatuses, systems, and methods for enhancement of MBMS transmission reliability. A UE may receive PDCP PDUs via a PTM link from a network. The UE may determine to provide feedback regarding receipt of the PDCP PDUs, e.g., based, at least in part, on an occurrence of a triggering event. The triggering event may be configured by the network and may include the UE receiving a request for feedback from the network, the UE determining that at least one PDCP PDU is missing, the UE determining that a number of missing PDCP PDUs exceeds a threshold, and/or the UE determining that a PDCP reordering window is changing based on expiration of a PDCP reordering timer. The UE may transmit feedback associated with receipt of the PDCP PDUs. The feedback may include an indication of missing PDCP PDUs, e.g., such as an indication of a sequence number associated with missing PDCP PDUs.

A method is performed by a wireless device for transmitting PDCP packets over a multi-hop path to a receiver, in accordance with particular embodiments. The method begins with receiving PDCP signalling indicating that at least one transmitted PDCP packet has not been received. For example, the PDCP signalling may comprise a PDCP status PDU, or may comprise PDCP data recovery or PDCP re-establishment RRC signalling. In response to receiving the PDCP signalling indicating that at least one transmitted PDCP packet has not been received, the wireless device retransmits the at least one transmitted PDCP packet that has not been received, even if said transmitted PDCP packet has been acknowledged by a lower protocol layer. A method is also performed by a network node in accordance with particular embodiments.

Certain aspects of the present disclosure provide techniques for handling acknowledgement and retransmission timers during sidelink discontinuous reception (DRX) communication. An example method by a transmitter user equipment (UE) generally includes transmitting a first repetition of a physical sidelink shared channel (PSSCH) to a receiver UE prior to entering an inactive state, while the transmitter UE is operating in a sidelink discontinuous reception (DRX) mode; returning to an active state to monitor for acknowledgment feedback from the receiver UE, wherein the return is based on a first timer relative to an end of the first repetition of the PSSCH; remaining in the active state for a duration defined by a second timer; and taking one or more actions depending on whether the transmitter UE receives acknowledgment feedback during the duration indicating failed reception of the first repetition of the PSSCH by the receiver UE.

A method and device for transmitting feedback information. The method includes: determining feedback type information and/or delay information when data is transmitted by a network device; and determining a reliability grade of a feedback transmission or that the feedback transmission is exempted at a certain situation, according to the delay information and/or the feedback type information. Therefore, HARQ feedback load may be reduced without impacting HARQ performances.

An apparatus including: an input interface configured to enable user configuration of a future time window; and a report interface configured to produce a report relating to a first sub-set of a plurality of active timers that expire at programmed future points in time, wherein the first sub-set of the plurality of active timers expire during the user-configured future time window.

In an indication information receiving method, a first terminal device receives first indication information from a first network device, and sends information about at least one HARQ process of the first terminal device to the first network device based on the first indication information, where the information about the at least one HARQ process includes a process number of a first HARQ process. The first terminal device receives first data from the first network device through the first HARQ process. This can improve reliability during data transmission.