Abstract: A first apparatus may be configured to generate a scheduling request to request to transmit at least one of data or control information on a sidelink channel. The first apparatus may be further configured to transmit, to another UE, the scheduling request on resources of a channel configured to carry feedback responsive to transmissions on the sidelink channel. A second apparatus may be configured to monitor resources on a channel for transmissions from other UE, the channel being configured to carry feedback from the other UE responsive to transmissions on a sidelink channel. The second apparatus may be further configured to receive at least one scheduling request from at least one of the other UE on the resources of the channel configured to carry the feedback based on monitoring the resources on the channel.

Abstract: Methods, systems, and devices for wireless communications are described. A transmitting device may transmit a polling request to a receiving device in sidelink control information that is associated with a sidelink data transmission. The polling request may be included in a sidelink control information message or in a medium access control layer message. The receiving device may respond to the polling request with an indication of whether there is data available for transmission to the transmitting device at the receiving device. The transmitting device may determine whether to schedule reverse sidelink resources for the receiving device to transmit the available data based on the response to the polling request.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may perform blind decoding, for sidelink control information (SCI) in resources in one or more sub-channels of a sidelink resource pool, based at least in part on an aggregation level or a resource aggregation configuration. The UE may receive the SCI based at least in part on performing the blind decoding for the SCI. Numerous other aspects are described.

Abstract: Systems and methods for implementing semi-persistent scheduling (SPS) transmission of periodic messages via one or more sidelinks are described. SPS for a sidelink groupcast may be activated and/or deactivated using SPS control signaling for the sidelink groupcast. SPS control signaling utilized for activating/deactivating SPS for a sidelink groupcast may include a SPS indicator (e.g., conveyed at least in part via SCI format 0-1 message), an activation/deactivation indicator (e.g., conveyed at least in part via SCI format 0-1 message and/or SCI format 0-2 message), and/or a configuration index (e.g., conveyed at least in part via SCI format 0-1 message and/or SCI format 0-2 message). Other aspects and features are also claimed and described.

Abstract: Methods, systems, and devices for wireless communications are described. A base station may send coupled configured grants to a transmitter user equipment (UE) and a receiver UE, respectively. For example, when transmitting a pair of configured grants that includes a first configured grant sent to a first UE and a second configured grant sent to a second UE, the base station may include an indication in each of the configured grants that sidelink semi-persistent scheduling resources are activated or deactivated. Additionally, the configured grants may indicate which UE is a receiver and which UE is a transmitter. For instance, the first configured grant may indicate that a first UE is to be the transmitter and a second configured grant indicate that a second UE is to be the receiver.

Abstract: Methods, systems, and devices for wireless communications are described. A first user equipment (UE) may receive, from a base station associated with the first UE and a second UE, a downlink control information activating a set of configured grant resources for transmissions from the second UE to the first UE. The UE may transmit, according to the downlink control information, a feedback message to the base station confirming receipt of the downlink control information.

Abstract: Aspects of the present disclosure provide techniques for configuring a search space for sidelink communications between a plurality of user equipments (UEs). Particularly, the techniques described herein configure a search space (e.g., subset of all available sub-channels) to decode the sidelink packets (e.g., physical sidelink control channel (PSCCH) and physical sidelink shared channel (PSSCH)) transmitted between a first UE and a second UE over sidelink communication without the need for the receiver UE (e.g., second UE) to perform blind decoding of all sidelink sub-channels as is currently required in conventional systems. Thus, the disclosed techniques reduce latency and maximize the resource utilization (e.g.

Abstract: This disclosure provides systems, methods, and apparatuses, including computer programs encoded on computer storage media, for wireless communication. In one aspect of the disclosure, a method of wireless communication performed by a user equipment (UE) includes receiving, from a base station, a grant message indicating a set of sidelink resources. The method further includes transmitting multiple unicast messages via multiple subgroups of the set of sidelink resources.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first user equipment (UE) may receive, from a base station, a downlink communication that includes an indication of a sidelink grant associated with the first UE. The first UE may identify, based at least in part on the sidelink grant, one or more sidelink resources in which a second UE is to transmit sidelink control information (SCI) to the first UE. The SCI may include information associated with a sidelink data transmission from the second UE to the first UE. Numerous other aspects are provided.

Abstract: A method performed by a first sidelink (SL) user equipment (UE) includes receiving a downlink control information (DCI) from a number of coupled DCIs. The DCI grants reception of a number of scheduled physical SL shared channels (PSSCHs) over an unlicensed SL carrier, and requests a hybrid automatic repeat request (HARQ) response for the scheduled PSSCHs. The method also includes receiving at least one of the PSSCHs from a second SL UE. The method further includes transmitting the HARQ response based on the at least one received PSSCH.

Abstract: Methods, systems, and devices for wireless communications are described for improving sidelink communication reliability. In some examples, a user equipment (UE) may map allocated sidelink resources from a logical domain to a physical domain, where the mapped resources may include greater frequency diversity in the physical domain. A frequency range of a sidelink control channel or of a sidelink data channel may be greater in the physical domain than in the logical domain after the mapping. In some examples, sidelink communications may be associated with an aggregation factor that represents a number of repetitions of a sidelink communication. In this example, a UE may repeat a sidelink communication within a contention-based resource pool a number of times before receiving feedback in order to increase communication reliability. A first UE may communicate a sidelink communication with a second UE using a resource mapping or repetitions of the sidelink communication.

Abstract: Methods, systems, and devices for wireless communications are described. A first user equipment (UE) may determine a first set of resources for communications over a sidelink communication link between the first UE and a second UE. The first UE may transmit, to the second UE via the sidelink communication link, a first sidelink control information including a reverse sidelink scheduling indicator based on determining the first set of resources. The first UE may additionally transmit, to the second UE via the sidelink communication link, a second sidelink control information indicating a second set of resources for reverse sidelink transmissions from the second UE to the first UE over the sidelink communication link, where transmitting the second sidelink control information is based on transmitting the first sidelink control information. The first UE may receive, from the second UE, a reverse sidelink message in response to transmitting the second sidelink control information.

Abstract: Systems and non-transitory computer-readable mediums for scheduling resources for a specific sidelink are described. Some embodiments provide scheduling of resources for a sidelink between a first user equipment (UE) in communication with a base station and a specified second UE in communication with the first UE, such as using downlink control information (DCI) and/or radio resource control (RRC) signaling. The scheduling of sidelink resources may be with respect to a dynamic grant (DG) or a configured grant (CG). Other aspects and features are also claimed and described.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a base station may determine an estimated total amount of resources for one or more retransmissions of communications among the base station, a controller, and a device, the one or more retransmissions associated with one or more transmissions between at least two of the base station, the controller, or the device; and transmit, to at least one of the controller or the device, an indication of an allocation of resources based at least in part on the estimated total amount of resources for the one or more retransmissions. Numerous other aspects are provided.

Abstract: Apparatus, methods, and computer-readable media for facilitating usage of memory of helping UEs during sidelink retransmission are disclosed herein. An example method for wireless communication at a first user equipment (UE) includes receiving, from a wireless device, a first packet and a second packet for sidelink retransmission to at least one second UE, the second packet being received after the first packet. The example method also includes dropping the first packet or the second packet prior to retransmission based on at least one of a packet priority or an indication from the wireless device.

Abstract: Systems and methods configured for supporting multi-hop communications are described. Embodiments provide unavailable packet signaling by a base station aiding a multi-hop communication link. For example, the base station may transmit a predetermined “unavailable” message (e.g., an explicit and affirmatively transmitted message having predetermined content and/or format transmitted according to the schedule of the failed message) when an uplink data transmission in a multi-hop communication link fails or is otherwise currently unavailable. The unavailable packet signaling may be provided in association with a semi-persistent scheduling (SPS) and control channel scheduled retransmission technique, such as for supporting Internet of things (IoT), such as industrial Internet of things (IIoT), traffic. Other aspects and features are also claimed and described.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a wireless device may receive, for communications with one or more of a base station or another wireless device, information identifying that an uplink transmission on a sidelink and a downlink transmission on a sidelink are to precede an uplink transmission on an access link and a downlink transmission on an access link. The wireless device may communicate, with the one or more of the base station or the other wireless device, based at least in part on the information identifying that the uplink transmission on the sidelink and the downlink transmission on the sidelink are to precede the uplink transmission on the access link and the downlink transmission on the access link. Numerous other aspects are provided.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a device may measure a set of reference signal receive power (RSRP) metrics for reference signals including one or more reference signals from a base station and one or more reference signals from a controller associated with the device; and determine, based at least in part on the RSRP metrics, a configuration for receiving communications from the controller via a direct communication link with the controller or via the base station. Numerous other aspects are provided.

Abstract: Certain aspects of the present disclosure provide techniques for a fallback retransmission for a sidelink. A method that may be performed by a user equipment (UE) includes monitoring a transmission from a node. The UE can determine that the transmission was not successfully decoded. The UE can send a feedback message to the node indicating that the transmission was not successfully decoded. The feedback message can also include an indication of whether the node or a base station (BS) retransmits the transmission. The node retransmits the transmission or indicates to the BS to retransmit based on the feedback message. The BS can configure the node, the UE, or both with one or more thresholds for determining whether the node or the BS retransmits the transmission.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a network node may receive an indication of a first set of parameters that corresponds to a direct communication link between an industrial internet-of-things (IIoT) device and a first controller; receive an indication of a second set of parameters that corresponds to an indirect communication link between the IIoT device and the first controller through a second controller; and schedule a communication on at least one of the direct communication link or the indirect communication link based at least in part on the first set of parameters and the second set of parameters. Numerous other aspects are provided.