Abstract: Apparatus, methods, and computer-readable media for facilitating autonomous synchronization are disclosed herein. For example, a UE may be configured to perform an initial synchronization directly to PSCCH and PSSCH when other synchronization sources, such as GNSS, a base station, and/or SLSS, are unavailable. An example method for wireless communication at a user equipment includes receiving a PSCCH. The example method also includes performing an initial synchronization based on the PSCCH. In some examples, the method may also include receiving a PSSCH, and determining a logical subframe number modulo 10 based on the PSSCH. The logical subframe number modulo 10 may correspond to a sequence seed.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) and another device (e.g., another UE) may transmit messages on a shared channel accessed in a half-duplex manner (e.g., within a vehicle-to-everything (V2X) network). The UE and the other device may transmit messages on semi-persistently scheduled (SPS) resources. A message of the UE and a transmission of the other device may collide (e.g., be transmitted in the same subframe). The UE may employ muting and measuring, in which the UE may refrain from transmitting on a SPS resource and may detect the transmission of the other device. Upon detection of other transmissions, the UE may perform resource reselection. During resource selection or resource reselection, the UE may exclude an entire subframe of candidate resources if one of the candidate resources of the subframe is mapped to a resource associated with a transmission from another device.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may adjust a basic safety message generation periodicity based at least in part on a semi-persistent scheduling periodicity for transmitting basic safety messages. The UE may generate one or more basic safety messages based at least in part on the adjusted basic safety message generation periodicity. Numerous other aspects are provided.

Abstract: A method, an apparatus, and a non-transitory computer readable medium for receiving data and one or more redundant equivalent versions of the data from a remote user equipment (UE), buffering the data and the one or more redundant equivalent versions of the data, transmitting the data to a base station, receiving at least one negative acknowledgement, relating to the data, from the base station indicating an unsuccessful reception of the data; and transmitting, in response to receiving the at least one negative acknowledgement, at least one of the one or more redundant equivalent versions of the data to the base station.

Abstract: Apparatus, methods, and computer-readable media for facilitating autonomous synchronization are disclosed herein. For example, a UE may be configured to perform an initial synchronization directly to PSCCH and PSSCH when other synchronization sources, such as GNSS, a base station, and/or SLSS, are unavailable. An example method for wireless communication at a user equipment includes receiving a PSCCH. The example method also includes performing an initial synchronization based on the PSCCH. In some examples, the method may also include receiving a PSSCH, and determining a logical subframe number modulo 10 based on the PSSCH. The logical subframe number modulo 10 may correspond to a sequence seed.

Abstract: Aspects of the present disclosure implement techniques that allow a vehicle performing V2X communications to provide more accurate S-RSSI measurements and CBR calculations for use in channel selection and congestion control. Techniques may include measuring a sidelink received signal strength indicator (S-RSSI) for each of a plurality of sub-channels, determining one or more signal impairment adjustment factors based on the S-RSSI for each of the plurality of sub-channels, calculating a channel busy ratio (CBR) for the plurality of sub-channels based on the one or more signal impairment adjustment factors, and initiating communication with at least one of the plurality of sub-channels based on at least the CBR.

Abstract: A method, an apparatus, and a non-transitory computer readable medium for receiving data and one or more redundant equivalent versions of the data from a remote user equipment (UE), buffering the data and the one or more redundant equivalent versions of the data, transmitting the data to a base station, receiving at least one negative acknowledgement, relating to the data, from the base station indicating an unsuccessful reception of the data; and transmitting, in response to receiving the at least one negative acknowledgement, at least one of the one or more redundant equivalent versions of the data to the base station.

Abstract: Aspects of the present disclosure provide techniques to enable enhanced machine type communication (s) (eMTC) and/or narrowband Internet-of-Things (NB-IoT) devices to transition to idle mode after releasing a connection, such as a radio resource control (RRC) connection, more quickly than with previously known techniques. An example method includes determining, based on an indication received in a narrowband signal on a narrowband region of a bandwidth comprising a plurality of narrowband regions, whether to wait for a delay period, determined based on a configuration received from a network entity, before releasing a radio resource control (RRC) connection and releasing the RRC connection at a time in accordance with the determination.

Abstract: A method, an apparatus, and a non-transitory computer readable medium for receiving data and one or more redundant equivalent versions of the data from a remote user equipment (UE), buffering the data and the one or more redundant equivalent versions of the data, transmitting the data to a base station, receiving at least one negative acknowledgement, relating to the data, from the base station indicating an unsuccessful reception of the data; and transmitting, in response to receiving the at least one negative acknowledgement, at least one of the one or more redundant equivalent versions of the data to the base station.

Abstract: Aspects directed towards synchronizing out of coverage (OOC) vehicle-to-everything (V2X) communications are disclosed. In one example, a scheduled entity detects a loss of a synchronization signal associated with a V2X communication by detecting when a timing uncertainty value or error value is greater than a threshold value. Packet timing information is then received in response to the loss of the synchronization signal from at least one user equipment (UE) synchronized with the synchronization signal. The scheduled entity then maintains the V2X communication by performing a timing adjustment based on the packet timing information.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may adjust a basic safety message generation periodicity based at least in part on a semi-persistent scheduling periodicity for transmitting basic safety messages. The UE may generate one or more basic safety messages based at least in part on the adjusted basic safety message generation periodicity. Numerous other aspects are provided.

Abstract: A method, apparatus, and computer-readable medium at a transmitting user equipment (UE) in a distributed cellular vehicle-to-everything environment are disclosed to determine a schedule for transmissions on subchannels of multiple frequencies based on a set of UE-specific, dynamic, and performance related metrics or criteria. The metrics may include an estimated number of users on a subchannel, a best-bandwidth fit, channel loading conditions, transmission range, and quality requirements of an application, among others. Such a schedule for transmissions on subchannels of multiple frequencies may result in either an improved capacity utilization, an improved communication quality, or both.

Abstract: Methods and apparatus for selection of radio access technology (RAT) based on device usage patterns are provided. A User Equipment (UE) obtains information relating to one or more Quality of Service (QoS) metrics for communication of data by the UE. The UE designates a Radio Access Technology (RAT) from a plurality of available RATs as a preferred RAT for the communication, based on the obtained information.

Abstract: Aspects of the present disclosure provide techniques to enable enhanced machine type communication (s) (eMTC) and/or narrowband Internet-of-Things (NB-IoT) devices to transition to idle mode after releasing a connection, such as a radio resource control (RRC) connection, more quickly than with previously known techniques. An example method includes determining, based on an indication received in a narrowband signal on a narrowband region of a bandwidth comprising a plurality of narrowband regions, whether to wait for a delay period, determined based on a configuration received from a network entity, before releasing a radio resource control (RRC) connection and releasing the RRC connection at a time in accordance with the determination.

Abstract: Methods, systems, and devices for wireless communications are described. A user equipment (UE) and another device (e.g., another UE) may transmit messages on a shared channel accessed in a half-duplex manner (e.g., within a vehicle-to-everything (V2X) network). The UE and the other device may transmit messages on semi-persistently scheduled (SPS) resources. A message of the UE and a transmission of the other device may collide (e.g., be transmitted in the same subframe). The UE may employ muting and measuring, in which the UE may refrain from transmitting on a SPS resource and may detect the transmission of the other device. Upon detection of other transmissions, the UE may perform resource reselection. During resource selection or resource reselection, the UE may exclude an entire subframe of candidate resources if one of the candidate resources of the subframe is mapped to a resource associated with a transmission from another device.

Abstract: Aspects directed towards synchronizing out of coverage (OOC) vehicle-to-everything (V2X) communications are disclosed. In one example, a scheduled entity detects a loss of a synchronization signal associated with a V2X communication by detecting when a timing uncertainty value or error value is greater than a threshold value. Packet timing information is then received in response to the loss of the synchronization signal from at least one user equipment (UE) synchronized with the synchronization signal. The scheduled entity then maintains the V2X communication by performing a timing adjustment based on the packet timing information.

Abstract: Aspects of the present disclosure implement techniques that allow a vehicle performing V2X communications to provide more accurate S-RSSI measurements and CBR calculations for use in channel selection and congestion control. Techniques may include measuring a sidelink received signal strength indicator (S-RSSI) for each of a plurality of sub-channels, determining one or more signal impairment adjustment factors based on the S-RSSI for each of the plurality of sub-channels, calculating a channel busy ratio (CBR) for the plurality of sub-channels based on the one or more signal impairment adjustment factors, and initiating communication with at least one of the plurality of sub-channels based on at least the CBR.

Abstract: A method, apparatus, and computer-readable medium at a transmitting user equipment (UE) in a distributed cellular vehicle-to-everything environment are disclosed to determine a schedule for transmissions on subchannels of multiple frequencies based on a set of UE-specific, dynamic, and performance related metrics or criteria. The metrics may include an estimated number of users on a subchannel, a best-bandwidth fit, channel loading conditions, transmission range, and quality requirements of an application, among others. Such a schedule for transmissions on subchannels of multiple frequencies may result in either an improved capacity utilization, an improved communication quality, or both.

Abstract: A method, an apparatus, and a non-transitory computer readable medium for receiving data and one or more redundant equivalent versions of the data from a remote user equipment (UE), buffering the data and the one or more redundant equivalent versions of the data, transmitting the data to a base station, receiving at least one negative acknowledgement, relating to the data, from the base station indicating an unsuccessful reception of the data; and transmitting, in response to receiving the at least one negative acknowledgement, at least one of the one or more redundant equivalent versions of the data to the base station.

Abstract: Methods and apparatus for selection of radio access technology (RAT) based on device usage patterns are provided. A User Equipment (UE) obtains information relating to one or more Quality of Service (QoS) metrics for communication of data by the UE. The UE designates a Radio Access Technology (RAT) from a plurality of available RATs as a preferred RAT for the communication, based on the obtained information.