Abstract: The disclosure provides for control plane measurements in a wireless device. The wireless device may measure, across multiple sub-frames received over an unlicensed spectrum, received cell-specific reference signals (CRS) from a cell to obtain CRS measurements. The wireless device may identify one or both of a first subset of the CRS measurements associated with a first subset of the sub-frames including opportunistic transmissions and a second subset of the CRS measurements associated with a second subset of the sub-frames including guaranteed transmissions. The wireless device may compute one or both of a first signal to interference plus noise ratio (SINR) value for the first subset of the CRS measurements and a second SINR value for the second subset of the CRS measurements. The wireless device may monitor a radio link condition of the wireless device based at least in part on the first SINR value or the second SINR value.

Abstract: Methods, systems, and devices for wireless communications are described, in which for one or more aspects of a first transmission of a first radio access technology (RAT) (e.g., a 5G or New Radio (NR) RAT) are determined based on transmissions of a second RAT (e.g., a 4G or Long Term Evolution (LTE) RAT). A user equipment (UE) may, in some cases, determine a reference timing, a reference power, or combinations thereof for an uplink transmission of the first RAT based on a received power or reference timing of the second RAT. In some cases, handover for the first RAT may be based at least in part on an handover in the second RAT.

Abstract: Techniques are described for wireless communication. A first method may include inserting, in a first transmission using a first radio access technology (RAT), a channel occupancy identifier for a second transmission using a second RAT. The first method may also include transmitting the first transmission having the channel occupancy identifier over an unlicensed radio frequency spectrum band. A second method may include receiving, at a receiver operated using a first RAT, a channel occupancy identifier for a transmission using a second RAT. The channel occupancy identifier may be received over an unlicensed radio frequency spectrum band. The second method may also include decoding the channel occupancy identifier to identify a backoff period, and refraining from accessing the unlicensed radio frequency spectrum band using the first RAT based at least in part on the identified backoff period.

Abstract: Techniques are provided herein for establishing an ad hoc aircraft-to-aircraft mesh network to provide a redundant backup of critical flight information for an aircraft. Using a directional communication link of the aircraft-to-aircraft mesh network, the aircraft can transmit at least a portion its critical flight information to one or more receiving aircraft. The receiving aircraft may store the critical flight information of the transmitting aircraft on a local memory device. At least portions of the critical flight information may be reconstructed from the data stored on the receiving aircraft. In some examples, the receiving aircraft may retransmit the critical flight information to other aircraft.

Abstract: Techniques for transmitting and receiving wireless communications over an unlicensed radio frequency spectrum band are disclosed, including techniques for transmitting and receiving system information blocks over the unlicensed radio frequency spectrum band, techniques for gaining access to the unlicensed radio frequency spectrum band by performing extended clear channel assessments (ECCAs), techniques for transmitting and receiving synchronization signals and reference signals over the unlicensed radio frequency spectrum band, techniques for identifying starting times of downlink transmissions over the unlicensed radio frequency spectrum band, techniques for transmitting and receiving clear channel assessment (CCA)-exempt transmissions over the unlicensed radio frequency spectrum band, techniques for performing random access over the unlicensed radio frequency spectrum band, and techniques for dynamically modifying a transmission mode over the unlicensed radio frequency spectrum band.

Abstract: Methods, systems, and devices are described for hierarchical communications and low latency support within a wireless communications system. An eNB and/or a UE may be configured to operate within the wireless communications system which is at least partially defined through a first layer with first layer transmissions having a first subframe type and a second layer with second layer transmissions having a second subframe type. The first subframe type may have a first round trip time (RTT) between transmission and acknowledgment of receipt of the transmission, and the second layer may have a second RTT that is less than the first RTT. Subframes of the first subframe type may be multiplexed with subframes of the second subframe type, such as through time division multiplexing. In some examples symbols of different duration may be multiplexed such that they different symbol durations coexist.

Abstract: Protection of transmission and reception of clear channel assessment (CCA)-exempt transmission (CET) is disclosed in which channel reserving signals or protection signals may be transmitted by the transmitter or receiver of the CET. The transmitted signals may be received by the neighboring access points that could potentially cause interference with the reception of the CET.

Abstract: Systems and methods for uplink transmission scheduling are disclosed. A wireless device may monitor at least two downlink sub-frames for scheduling grants. The wireless device may receive a first uplink scheduling grant in one of the at least two downlink sub-frames for at least a first uplink sub-frame and receive a second uplink scheduling grant in another of the at least two downlink sub-frames for at least the first uplink sub-frame. The wireless device may perform an uplink transmission in the first uplink sub-frame based on one or both of the first uplink scheduling grant and the second uplink scheduling grant. For the uplink transmission, the wireless device may select a most recent uplink scheduling grant or select an uplink scheduling grant received in a downlink sub-frame at least a minimum number of sub-frames before the first uplink sub-frame.

Abstract: Techniques are described for conveying identification information in a preamble transmission. A transmission burst may be generated for transmission over a wireless medium. The transmission burst may include the preamble and a body portion. The preamble may include identification information associated with at least one of a transmitting device or a category of data bring transmitted. The transmission burst may then be transmitted over the wireless medium.

Abstract: Methods, systems, and devices are described for hierarchical communications and low latency support within a wireless communications system. An eNB and/or a UE may be configured to operate within the wireless communications system which is at least partially defined through a first layer with first layer transmissions having a first subframe type and a second layer with second layer transmissions having a second subframe type. The first subframe type may have a first round trip time (RTT) between transmission and acknowledgment of receipt of the transmission, and the second layer may have a second RTT that is less than the first RTT. Subframes of the first subframe type may be multiplexed with subframes of the second subframe type, such as through time division multiplexing. In some examples symbols of different duration may be multiplexed such that they different symbol durations coexist.

Abstract: Methods and apparatus for wireless communication are described. A method may include receiving at a user equipment (UE) a number of allocated interlaces for an uplink transmission over a shared spectrum, each of which may include a plurality of non-contiguous resource blocks (RB) of the shared spectrum. In some cases, the number of allocated interlaces is unsupported by joint interlace precoding hardware of the UE and the allocated interlaces may be partitioned into subsets of interlaces which may be a size supported by the joint interlace precoding hardware. Reference signals may be generated for the RBs of the allocated interlaces according to a reference signal sequence based on an ordering of the RBs for the allocated interlaces within the shared spectrum.

Abstract: Techniques are described for wireless communication. A first method may include receiving at a user equipment (UE) over an unlicensed radio frequency spectrum band an indication of a time window associated with a transmission of a synchronization signal, and monitoring the unlicensed radio frequency spectrum band during the time window to receive a synchronization signal from a base station. A second method may include transmitting an indication of a time window associated with a transmission of a synchronization signal; performing a plurality of clear channel assessments (CCAs) on an unlicensed radio frequency spectrum band during the time window; and transmitting the synchronization signal over the unlicensed radio frequency spectrum band at a transmission time during the time window. The transmission time may be based at least in part on a result of at least one of the CCAs.

Abstract: Techniques are provided for combining different types of reference signals. A wireless communications network may be configured to allow a user equipment (UE) to combine multiple demodulation reference signals (DM-RSs) to support demodulation of a physical downlink shared channel (PDSCH), and/or other downlink transmissions, transmitted from a base station to the UE. The base station may provide explicit signaling that reference signals transmitted in two or more transmission time intervals may be combined, or a determination that reference signals transmitted in two or more transmission time intervals may be combined may be made implicitly based on system configuration and previous transmissions. Based on the explicit signaling and/or implicit determination, a UE may combine reference signals included in each of two or more reference signals for use in demodulation of downlink transmissions.

Abstract: Methods and apparatuses are described for wireless communications. A first method includes transmitting a first Orthogonal Frequency-Division Multiple Access (OFDMA) communications signal to a wireless node in a licensed spectrum, and transmitting, concurrently with the transmission of the first OFDMA communications signal, a second OFDMA communications signal to the wireless node in an unlicensed spectrum. A second method includes receiving a first Orthogonal Frequency-Division Multiple Access (OFDMA) communications signal from a wireless node in a licensed spectrum, and receiving, concurrently with the reception of the first OFDMA communications signal, a second OFDMA communication signal from the wireless node in an unlicensed spectrum.

Abstract: Techniques are described for wireless communication. A first method includes generating uplink control information at a wireless device, and transmitting the uplink control information over an interlace of a component carrier of an unlicensed radio frequency spectrum band. The interlace includes a plurality of non-contiguous concurrent resource blocks in the unlicensed radio frequency spectrum band, and at least two resource blocks in the interlace include different portions of the uplink control information. A second method includes generating uplink control information at a wireless device, and transmitting the uplink control information over an uplink control channel of an unlicensed radio frequency spectrum band. Resources of the uplink control channel are divided into a plurality of discrete dimensions and the uplink control information of the wireless device is transmitted over a number of the discrete dimensions allocated to the uplink control information of the wireless device.

Abstract: Techniques are described for wireless communication. A first method includes receiving downlink control information for a first UE based at least in part on a group identifier associated with a NOMA group including the first UE and at least a second UE; and receiving a set of NOMA downlink transmissions at the first UE based at least in part on the downlink control information for the first UE. A second method includes receiving downlink control information for a first UE, the downlink control information for the first UE including an indication of at least a second UE; receiving downlink control information for the second UE based at least in part on the indication of at least the second UE; and receiving a set of NOMA downlink transmissions at the first UE based at least in part on the downlink control information for the first UE and the downlink control information for the second UE.

Abstract: Methods and apparatuses are described in which an unlicensed spectrum is used for Long Term Evolution (LTE) communications. A first method includes comparing past transmission activity on an unlicensed spectrum to an activity threshold, transmitting a first subframe type in the unlicensed spectrum during a next active transmission when the past transmission activity is greater than the activity threshold, and transmitting a second subframe type in the unlicensed spectrum during a next active transmission when the past transmission activity is lesser than the activity threshold, the second subframe type comprising a more robust subframe type than the first subframe type. A second method includes generating one or both of PUCCH signals and PUSCH signals based on interleaved signals that increase nominal bandwidth occupancy in an unlicensed spectrum, and transmitting the generated signals in the unlicensed spectrum. A third method includes receiving the PUCCH signals and the PUSCH signals.

Abstract: Certain aspects of the present disclosure provide techniques that may be used to help enable low latency communications between a user equipment (UE) and a base station (BS) using quick uplink channels that enable a reduced transmission time interval (TTI). Additionally, certain aspects of the present disclosure provide techniques for managing communications in a wireless communication system, for example, by using enhanced downlink control channels.

Abstract: Certain aspects of the present disclosure provide techniques that may be used to help enable low latency communications between a user equipment (UE) and a base station (BS) using quick uplink channels that enable a reduced transmission time interval (TTI). Additionally, certain aspects of the present disclosure provide techniques for managing communications in a wireless communication system, for example, by using enhanced downlink control channels.

Abstract: Techniques are described for wireless communication. A first method may include receiving at a user equipment (UE) over an unlicensed radio frequency spectrum band an indication of a time window associated with a transmission of a synchronization signal, and monitoring the unlicensed radio frequency spectrum band during the time window to receive a synchronization signal from a base station. A second method may include transmitting an indication of a time window associated with a transmission of a synchronization signal; performing a plurality of clear channel assessments (CCAs) on an unlicensed radio frequency spectrum band during the time window; and transmitting the synchronization signal over the unlicensed radio frequency spectrum band at a transmission time during the time window. The transmission time may be based at least in part on a result of at least one of the CCAs.