Abstract: This disclosure provides systems, methods and apparatus, including computer programs encoded on computer storage media, for establishing directional communications between two communication nodes via a configurable reflective surface. In some aspects, an assisting node (AN) may control a reflection characteristic (which may dictate or influence how signals reflect off of the configurable reflective surface) in accordance with parameters or configurations for directional communication between the two communication nodes. For example, the AN may use a first beam for directional communication with the first node and a second beam for directional communication with the second node, and the AN may control the reflection characteristic in accordance with an inferred incident direction of signaling at the configurable reflective surface and a desired reflected direction of the signaling from the configurable reflective surface that are associated with the first beam and the second beam, respectively.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first mobile station may transmit a signal on each of multiple sidelink carriers. The first mobile station may receive one or more signals on one or more of the multiple sidelink carriers. The first mobile station may select a primary carrier among the multiple sidelink carriers and a secondary carrier among the multiple sidelink carriers based at least in part on the signals received on multiple sidelink carriers. The first mobile station may negotiate which of the multiple sidelink carriers are to be an agreed primary carrier and an agreed secondary carrier. Numerous other aspects are described.

Abstract: Aspects relate to techniques for enabling a UE to detect a potential mistrusted UE that may be sharing inaccurate sidelink assistance information with other UEs. In an aspect, a first UE may receive a plurality of sidelink assistance information from other UEs. The first UE can further identify an amount of the plurality of sidelink resources for which a second UE provides respective inconsistent sidelink assistance information with respect to other UEs. In response to the amount exceeding a mistrust detection threshold, the first UE can transmit a report indicating that the second UE is a potential mistrusted UE to a centralized node. Based on the received reports associated with the second UE, the centralized node can transmit a mistrust indication indicating that the second UE is an actual mistrusted UE with respect to subsequent sidelink assistance information associated with the second UE.

Abstract: Aspects present herein relate to methods and devices for wireless communication including an apparatus, e.g., a UE and/or a base station. The apparatus may receive, from a base station, a security mode command message associated with secure sidelink communication with at least one other UE. The apparatus may also identify, based on the security mode command message, at least one of a RRC encryption key or a user plane encryption key. Additionally, the apparatus may receive, from the base station, an indication of at least one of a common base key or the RRC encryption key. The apparatus may also identify a physical layer sidelink encryption key based on at least one of the common base key or the RRC encryption key, the physical layer sidelink encryption key being associated with the secure sidelink communication with the at least one other UE.

Abstract: Methods, systems, and devices for wireless communications are described. The method may include a first wireless device transmitting, to a third wireless device associated with a signal relaying device, a first message querying whether the third wireless device is able to establish a first communications link with a second wireless device. The first wireless device may receive, from the third wireless device, signaling indicative of whether the third wireless device is able to establish the first communications link with the second wireless device and communicate with the second wireless device via a second communications link using a signal relaying device of the one or more signal relaying devices associated with the third wireless device based on the signaling.

Abstract: Methods, systems, and devices for wireless communications are described. A first user equipment (UE), e.g., such as a pedestrian UE (PUE), may detect, during a first transmission period of a discontinuous transmission cycle, a transmission over a sidelink channel from a second UE that is located within a threshold distance from the first UE, the first UE associated with a first identifier. The first UE may determine, based at least in part on the transmission, a second identifier associated with the second UE, the second identifier being different from the first identifier. The first UE may use, based at least in part on the second UE being within the threshold distance, the first identifier and the second identifier during one or more subsequent transmission periods of the discontinuous transmission cycle.

Abstract: Aspects relate to mechanisms for a base station to provide sidelink synchronization assistance to a plurality of user equipment (UEs). The base station may be configured to identify a detection time window that includes a sidelink synchronization resource configured for transmission of a sidelink synchronization signal on a sidelink carrier. The base station may further be configured to transmit an indication of the detection time window to the plurality UEs on a cellular carrier to enable the UEs to detect a sidelink synchronization signal on the sidelink carrier within the detection time window and synchronize communication on the sidelink carrier.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first user equipment (UE) may transmit, to a second UE via reflection by one or more passive devices, a first reference signal (RS) that is based at least in part on a shared first key that corresponds to a configuration of the one or more passive devices. The first UE may receive, from the second UE via reflection, a second RS that is based at least in part on the first key. The first UE may generate a second key based at least in part on a measurement of the second RS. The first UE may transmit a positioning reference signal that is based at least in part on the second key and that is associated with a measurement of a range between the first UE and the second UE. Numerous other aspects are described.

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 or a roadside unit (RSU), information associated with one or more security keys for sidelink communications, wherein the information includes at least one of a base key, the one or more security keys, or one or more parameters for deriving the one or more security keys. The UE may transmit, to a second UE, a sidelink communication that is scrambled using a security key of the one or more security keys. Numerous other aspects are described.

Abstract: Methods, systems, and devices for wireless communications are described. For example, a base station may receive, from a first user equipment (UE), an uplink message that includes one or more sidelink communication identifications each associated with a different UE of a set of one or more UEs and may associate each of the one or more sidelink communication identifications with a corresponding second identification also associated with each of the set of one or more UEs. The base station may transmit one or more signals for transitioning each of the set of one or more UEs associated with the set of second identifications from an inactive mode to an active mode based on associating each of the set of one or more sidelink communication identifications with the second identification of the set of second identifications.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a vulnerable road unit (VRU) device may determine that a parameter associated with movement of the VRU device satisfies one or more thresholds indicated in an event reporting configuration. The VRU device may transmit, to a vehicle user equipment device, an indication of an event associated with the VRU device based at least in part on determining that the parameter satisfies the one or more thresholds. Numerous other aspects are provided.

Abstract: Certain aspects of the present disclosure provide a method for wireless communications between a first UE and a second UE. The method includes, at the first UE, receiving, from the second UE, a paging indication message on a sidelink channel, the paging indication message associating the first UE with one or more resources of a common resource pool that includes a plurality of resources for communication on the sidelink channel. The method further includes, based on the received paging indication message, monitoring the one or more resources for a message from the second UE.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first vehicle user equipment (VUE) may transmit, to a node, first information associated with a presence of an object in a region of interest based at least in part on a sensing of the region of interest performed by the first VUE. The VUE may receive, from the node, second information associated with the presence of the object in the region of interest based at least in part on a sensing of the region of interest performed by a second VUE. The VUE may determine whether the object is present in the region of interest based at least in part on the first information and the second information. The VUE may perform an action based at least in part on whether the object is present in the region of interest. Numerous other aspects are provided.

Abstract: Apparatus, methods, and computer-readable media for facilitating relay of superpositioned sidelink and uplink transmission are disclosed herein. An example method for wireless communication at a first communication device includes receiving, from a UE, a MUST transmission including a base layer and an enhancement layer, the base layer comprising a first message for a second communication device and the enhancement layer comprising a second message for the first communication device. The example method also includes decoding the base layer of the MUST transmission to obtain the first message. Additionally, the example method includes receiving a feedback message from the second communication device indicating that the second communication device did not successfully receive the first message. The example method also includes retransmitting the first message to the second communication device in response to the feedback message from the second communication device.

Abstract: Methods, apparatuses, and computer-readable medium for directional security are provided. An example method may include receiving, from a wireless device, a configuration for a set of shared keys. The example method may further include receiving, from a second UE, at least one message or signal including a location of the second UE, the received at least one message or signal being associated with an angle of arrival. The example method may further include configuring a key from the set of shared keys based on at least one of the received configuration, the location of the second UE, the AoA of the received at least one message or signal, or a location of the first UE. The example method may further include generating one or more ranging signals based on the configured key, the one or more ranging signals being directionally secure based on the location of the second UE.

Abstract: Methods, systems, and devices for wireless communications are described. The described techniques relate to the categorization of resources in a system to enable a user equipment (UE) to determine whether resources may be reclaimed. At least two categories may be defined for the resources, and the UE may use various criteria for categorizing the resources in a system. For example, the UE may include a first set of resources in an “available” category and a second set of resources in an “occupied” category. Resources in the “occupied” category may be indicated as occupied by another UE's sidelink channel information. In cases where resources are indicated as reserved for retransmission by another UE, but no feedback is detected, then the UE may use additional parameters to determine whether those resources may be reclaimed for its own transmission and may categorize the resources accordingly.

Abstract: Methods, systems, and devices for wireless communications between a first device and a second device using a sidelink network are described. The second device may generate a wake-up signal (WUS) including a destination identifier indicating a destination node of the sidelink channel configured to receive the WUS. The first device may receive, from the second device, the WUS including the destination identifier. The first device may identify that the destination identifier indicated by the WUS is associated with the first device based on receiving the WUS. The first device may monitor resources of the sidelink channel based on identifying that the destination identifier is associated with the first device. The destination identifier may be indicated by an information element. Additionally or alternatively, the second device may generate the destination identifier using a gold sequence or a low peak-to-average-power ratio sequence.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) in a vehicle-to-everything (V2X) system may receive configuration information from an assisting node, such as a roadside unit (RSU), for calculating location information for a target UE in the V2X system. The assisting node may reflect one or more radar signals from the UE towards the target, and from the target back towards the UE according to the configuration information. That is, the assisting node may modify one or more waveform parameters of the reflection according to the configuration information. The UE may calculate location information for the target based on the reflection, such as by classifying the target as non-line-of-sight (NLOS) based on modified waveform parameters, location information of the assisting node, or both.

Abstract: Methods, systems, and devices for sidelink wireless communications are described in which a user equipment (UE), such as a vehicle UE, that supports full-duplex communications may transmit a sidelink control channel during a set of time resources including scheduling information for a subsequent transmission by the UE via a first set of resources. The UE may receive a sidelink control channel during the set of time resources from a second UE that may support full-duplex communications or half-duplex communications. The sidelink control channel may include scheduling information for a subsequent transmission via a second set of time-frequency resources that at least partially overlaps with the first set of time-frequency resources. The first UE may determine that a collision will occur and may perform a resource selection procedure or may transmit a request for the second device to perform the resource selection procedure.

Abstract: Methods, systems, and devices for wireless communications are described. For instance, a first user equipment (UE) may identify a configuration for an assisting node (AN) that includes an indication of a set of time resources during which the AN is active and an indication of location information that indicates communication direction information corresponding to communications via the AN during the set of time resources. The first UE may select a time resource from the set of time resources based on the indication of location information, a location of the first UE, and information associated with a packet for transmission from the first UE to a second UE via the assisting node. The first UE may transmit the packet over the selected time resource.