Abstract: In one aspect, a method includes determining, by a user equipment (UE), a channel busy ratio (CBR) window for a CBR measurement for one or more resources; determining, by the UE, a CBR measurement value for the CBR window and for the one or more resources; determining, by the UE, a channel occupancy ratio (CR) window based on a first number of subframes used for a history of past transmissions and based on a second number of subframes used for future planned transmissions and corresponding retransmissions; and determining, by the UE, a CR value for the CR window based on subchannels used for the one or more resources for the first number of subframes and based on subchannels estimated for the one or more resources for the second number of subframes. In another aspect, a method includes determining a CR window based on a CBR measurement value.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may identify one or more spectral efficiency ranges that are to be used to select a modulation and coding scheme (MCS) for a sidelink communication. The UE may transmit the sidelink communication using the MCS selected based at least in part on the one or more spectral efficiency ranges. Numerous other aspects are provided.

Abstract: Methods, systems, and devices for wireless communication are described. A transmitting device may select an orthogonal metric based at least in part on at least one of each direction of a plurality of directions to transmit millimeter wave discovery signals or a location parameter associated with the transmitting device. The transmitting device may transmit, in the each direction of the plurality of directions, the millimeter wave discovery signals, where the each transmitted millimeter wave discovery signal has a different orthogonal metric applied that was selected based at least in part on the at least one of the each direction or the location parameter.

Abstract: Methods, apparatuses, and computer-readable mediums for wireless communication by a user equipment (UE) includes transmitting a packet on a first resource, determining one or more repetition resources on which to send one or more redundancy versions of the packet, wherein the one or more repetition resources are at a time subsequent to the first resource, transmitting repetition resource information identifying the one or more repetition resources to one or more neighboring UEs, and transmitting the one or more redundancy versions of the packet on respective ones of the one or more repetition resources.

Abstract: Aspects described herein relate to determining a congestion level related to communicating with one or more devices in a wireless network, determining, based on the congestion level, a retransmission scheme for transmitting and/or retransmitting communications in the wireless network, and transmitting or retransmitting a communication in the wireless network based on the retransmission scheme.

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: Methods, systems, and devices for wireless communications are described in which two or more UEs of a wireless communications system may establish a sidelink connection. A first UE that is initiating sidelink communications may evaluate whether the sidelink connection can support a quality of service (QoS) for a data flow prior to admitting the data flow. The first UE may evaluate a link quality with one or more other UEs that are to use the data flow on the sidelink connection, evaluate system congestion of time/frequency resources that are available for the sidelink connection, or any combinations thereof, and admit the data flow based on the evaluation. A link quality of the sidelink connection may be determined based on a type of communication associated with the data flow, such as unicast communications with one other UE, multicast communications with multiple other UEs, or broadcast transmissions to multiple UEs.

Abstract: Certain aspects of the present disclosure provide techniques for channel estimation for two-stage sidelink control using sidelink data channel demodulation reference signals (DMRS). A user equipment (UE) can transmit DMRS for the sidelink data channel. The UE may transmit the second stage of the sidelink control using antenna ports or a precoder used for the sidelink data channel. The receiving device may receive the DMRS, estimate the channel, and demodulate the second stage of the sidelink control based on the estimated channel. The receiving device may flexibly determine the DMRS to use for the estimation and demodulation.

Abstract: Methods, systems, and devices for wireless communications are described that may enable a user equipment (UE) to transmit sidelink data within an interference avoidance resource scheduling scheme. For example, a UE may determine to segment a data packet for transmission in a vehicle-to-everything (V2x) system (e.g., to ensure that each segment fits within one transmission time interval (TTI)). In some cases, a UE may identify a data packet for transmission, may determine that the size of the data packet exceeds a threshold size, may segment the data packet to ensure each segment fits within one TTI, and may transmit the data packet segments (e.g., to additional UEs), where said transmissions may be discontinuous. In some examples, a UE may determine to segment the data packet and then encode the data packet. Additionally or alternatively, the UE may determine to encode the data packet and then segment the data packet.

Abstract: Methods, apparatuses, and computer-readable mediums for wireless communication are disclosed by the present disclosure. In an example, a host wireless device may transmit a discovery message to a client wireless device. The client wireless device may transmit a random access channel (RACH) preamble on a first time domain resource to the host wireless device in response to the discovery message. The client wireless device may later transmit a second RACH message to the host device on a second time domain resource after the first time domain resource. The second time domain resource may be defined by a mapping from the first time domain resource. The host device may transmit a third RACH message establishing a communication session between the host wireless device and the client wireless device.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive a first set of synchronization signals from a first synchronization source and may receive a second set synchronization signals from a second synchronization source, where the UE determines a first priority for the first synchronization source based on a first identification (ID) associated with the first set of synchronization signals and a second priority for the second synchronization source based on a second ID associated with the second set of synchronization signals. Accordingly, the UE may then select the first synchronization source or the second synchronization source based on which synchronization source has a higher priority and communicate with the selected synchronization source (e.g., via sidelink communications).

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may determine, for a device-to-device communication with another UE, a modulation and coding scheme (MCS) configuration, of a set of MCS configurations, based at least in part on at least one of a transmission mode, a packet characteristic, a mobility state of the UE, a capability of the UE, a transmission mode of the device-to-device communication, a received indication from the other UE, or a combination thereof. The UE may transmit, to the other UE, data using an MCS selected based at least in part on the MCS configuration. Numerous other aspects are provided.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a base station, a discontinuous reception (DRX) configuration to be used by the UE for cellular communication with the base station, wherein the DRX configuration indicates a DRX cycle that includes an active time during which the UE is to monitor a physical downlink control channel (PDCCH) and an inactive time during which the UE is to refrain from monitoring the PDCCH; identify a time window for sidelink communication with another UE based at least in part on the DRX configuration; and communicate using one or more sidelink resources in the identified time window. Numerous other aspects are provided.

Abstract: Methods, systems, and devices for wireless communications are described. The method, system, and apparatus may include managing the operation mode of a user equipment in vehicle-to-everything communication. In some aspects, a user equipment may transmit an inactive request message (or a request message) to a base station to indicate the user equipment is switching from a base station scheduling mode (or a radio access network node scheduling mode) to a peer user equipment scheduling mode (or a roadside unit scheduling mode). The user equipment may receive an acknowledgment message from the base station indicating a state change to allow the peer user equipment scheduling mode. In some cases, the user equipment may receive an area identifier from the base station, and the area identifier may indicate an area where the peer user equipment scheduling mode is allowed.

Abstract: Certain aspects of the present disclosure provide techniques for improving sidelink positioning via messaging between wireless nodes, e.g., roadside service units (RSUs). A method that may be performed by a user equipment (UE) includes receiving a first positioning reference signal (PRS) from a first wireless node, receiving a second PRS from a second wireless node, receiving, from the first wireless node, an estimate of a first clock error component between the first wireless node and the second wireless node, and estimating a position of the UE, based on the first PRS, the second PRS, and the estimate of the first clock error component.

Abstract: Disclosed are techniques for wireless communication. In an aspect, a transmitter user equipment (UE) determines a first zone identifier (ID) corresponding to a first zone in which the transmitter UE is located, determines a distance threshold based on a distance requirement of an application associated with the transmitter UE, determines a second zone ID based on the first zone ID, the distance threshold, a size of the first zone, or any combination thereof, and transmits the second zone ID and the distance threshold to one or more receiver UEs. In an aspect, the receiver UE receives the second zone ID and the distance threshold, determines a distance between the receiver UE and the transmitter UE based on the second zone ID and a location of the receiver UE, and transmits, based on the distance being less than the distance threshold, a feedback message to the transmitter UE.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE), may receive, at a processing layer of the UE, sets of discontinuous reception (DRX) cycle parameters from a corresponding set of applications at an application layer of the UE. The UE may determine, based on the sets of DRX parameters, a common DRX cycle to satisfy each of the sets of applications. The UE may transmit the common DRX cycle to one or more layers in the user plane protocol stack of the UE. A base station may also receive a request, from the UE, for a set of DRX cycle parameters that satisfies the common DRX cycle of the UE. The base station may transmit an indication of the set of DRX parameters, and receive, from the UE, a confirmation of a DRX cycle associated with the set of DRX cycle parameters.

Abstract: Disclosed are techniques for using ranging signals to determine a position of a pedestrian user equipment (P-UE). In an aspect, a UE receives a plurality of ranging signals transmitted by one or more UEs, measures one or more properties of each of the plurality of ranging signals, and calculates an estimate of the position of the P-UE based on the one or more properties of each of the plurality of ranging signals. In an aspect, the P-UE transmits a plurality of ranging signals, receives a first message and a second message from first and second vehicle UEs (V-UEs), the first and second messages including first and second estimated positions of the P-UE and associated first and second confidences, and calculates an estimate of the position of the P-UE based on the first estimated position, the first confidence, the second estimated position, the second confidence, or a combination thereof.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may transmit, to another UE, a positioning request associated with a procedure for determining a position of the UE, wherein the positioning request comprises a sidelink communication between a first sidelink location management component (S-LMC) of the UE and a second S-LMC of the other UE, wherein the first S-LMC and the second S-LMC comprise sub-functions associated with a vehicle-to-everything protocol layer; and receive a positioning report associated with the procedure for determining the position of the UE, wherein the positioning report comprises an indication of the position of the UE based at least in part on a determination by a sidelink location management function. Numerous other aspects are provided.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first wireless communication device may iterate a value of a channel access counter (CAC) to a trigger value based at least in part on configuring the value of the CAC. In some aspects, the first wireless communication device may utilize a channel access mechanism to select a set of time-frequency resources for a transmission of a packet based at least in part on iterating the value of the CAC to the trigger value. In some aspects, the first wireless communication device may transmit the packet to a second wireless communication device via the set of time-frequency resources based at least in part on utilizing the channel access mechanism to select the set of time-frequency resources for the transmission. Numerous other aspects are provided.