Abstract: Methods, systems, and devices for wireless communication are described. A user equipment (UE) may receive a downlink transmission from a base station, transmit a first stage of feedback for the downlink transmission, identify a condition associated with the downlink transmission, and determine whether to transmit a second stage of feedback for the downlink transmission based at least in part on the identified condition associated with the downlink transmission. The second stage of feedback for the downlink transmission may be transmitted (or not transmitted) based at least in part on the identified condition associated with the downlink transmission.

Abstract: Methods, systems, and devices for wireless communication are described. A base station may select, and a user equipment (UE) may identify, an initial symbol of a transmission time interval (TTI) based on a particular characteristic of a communication link between the base station and UE. A two-symbol TTI for one UE may thus be scheduled to align with or complement a longer TTI for another UE. For instance, the initial symbol of a two-symbol TTI may be restricted to certain symbol periods of a Long Term Evolution (LTE) subframe to limit interference with other transmissions scheduled during the subframe (e.g., reference signals, control channels, guard periods, etc.). Additionally or alternatively, a UE may identify and blindly decode control channel transmissions for low latency communications by assuming a presence of reference signals within the symbols that include a low latency control channel.

Abstract: Methods, systems, and devices for wireless communication are described. A user equipment (UE) may determine separate uplink (UL) power limitations for multiple transmission time interval (TTI) durations based on distinct power control parameters. In some cases, an adjustment factor or a power backoff may be applied to communications using one TTI duration to ensure that total transmit power does not exceed a threshold. The UE and the serving base station may also identify one or more demodulation reference signal (DMRS) windows. UL data transmissions may be demodulated based on a DMRS sent during the same window. Transmit power control (TPC) commands may be applied at the beginning of each window. However, if an UL transmission is scheduled at the beginning of the window, the UE may wait until a DMRS transmission or until no more transmissions are scheduled for the window before applying the TPC adjustment.

Abstract: Methods, systems, and devices for wireless communication are described. A user equipment (UE) or a base station may identify a timing advance parameter and a processing parameter for the UE, and one or both may determine a hybrid automatic repeat request (HARQ) timing based on the identified parameters. For example, if the UE has a large timing advance or reduced processing capacity, a longer HARQ timing may be chosen. When the UE receives downlink (DL) transmissions from the base station, the UE may send an acknowledgement (ACK) or negative acknowledgement (NACK) based on the chosen HARQ timing. The base station may send a retransmission (in the case of a NACK) based on the HARQ timing. In some cases, the UE may request a specific HARQ timing, or request an updated timing advance. If HARQ synchronization is lost, the UE and the base station may default to a preconfigured HARQ timing.

Abstract: Coordinated wireless communications using multiple transmission time intervals (TTIs) are described. Multiple TTIs may include a first TTI and a second TTI, the second TTI having a shorter duration than the first TTI. One or more parameters may be determined for communications using the first TTI and the second TTI. A first parameter of the determined parameters for the second TTI may be associated or linked with a corresponding parameter of the first TTI, and communications using the first TTI or the second TTI may be performed using the first parameter. Wireless network nodes using the first TTI may form a CoMP cooperating set, and wireless network nodes using the second TTI may for another CoMP cooperating set, and the first parameter may be applied to each of the CoMP cooperating sets.

Abstract: Wireless devices may exchange data related to multiple available random access procedures for network access. A random access procedure of the available random access procedures may be selected, and a random access message transmitted based on the selected random access procedure. Available random access procedures may include procedures that provide for a different number of random access messages or that are for use in communications having different transmission time intervals (TTIs). For example, a random access procedure may include a total of two random access messages or a total of four random access messages for accessing the wireless communications network. The use of one random access procedure instead of the other may depend on a wireless device's location relative to its serving base station.

Abstract: Methods, systems, and devices for wireless communication are described. A wireless device may establish a configuration for at least one carrier based on multiple transmission time interval (TTI) lengths. Several TTI lengths may be associated in a TTI group, and aspects of the configuration may be the same for all TTIs having a TTI length in the TTI group. The device may then communicate using the carrier configuration based on the TTI group. In some cases, a second TTI group with different TTI lengths from the first group may also be identified, and the device may communicate using TTI from the second group using a different TTI group configuration. Aspects of a TTI group configuration may include a common control channel format, resource allocation granularity, hybrid automatic repeat request (HARQ) process, HARQ timing, soft buffer size, channel state information (CSI) reporting configuration, or an uplink control channel.

Abstract: Certain aspects of the present disclosure relate to methods and apparatus for mitigating resource conflicts between ultra low latency (ULL) and legacy transmissions. A base station may determine a region of a subframe having overlapping resource allocations for a first device of a first type (e.g., ULL device) and a second device of a second type (e.g., legacy device), wherein the first device of the first type has a capability to perform certain procedures with low latency relative to the second device of the second type that lacks the capability. The base station may modulate data from the region of the subframe for transmission to the first and the second devices, using a hierarchical modulation scheme.

Abstract: Techniques are described for wireless communication. A first method includes inserting channel or interference estimation modulation symbols into a sequence of data modulation symbols; performing a discrete Fourier transform (DFT) on a group of modulation symbols in the sequence of data modulation symbols, the group of modulation symbols including at least one of the channel or interference estimation modulation symbols; and generating a single-carrier frequency domain modulated (SC-FDM) symbol stream based at least in part on an output of the DFT.

Abstract: Methods, systems, and devices are described for wireless communication at a device. Demodulation reference signals (DMRS) may be used to facilitate demodulation of low latency control or data channels, or both. A wireless communication device may, for example, identify a carrier configuration with transmission time intervals (TTIs) of different durations. A carrier may be configured with TTIs that support low latency operations. A DMRS pattern for resources of a low latency TTI may be determined, and that first DMRS pattern may be based on a DMRS pattern for resources of another, longer-duration TTI. Devices may thus communicate using resources of a low latency TTI based on the first DMRS pattern. For example, a user equipment (UE) may demodulate resources of a low latency channel using the first DMRS pattern, and the first DMRS pattern may be consistent with DMRS patterns supporting non-low latency within a common wireless system.

Abstract: Methods for managing hybrid automatic repeat request (HARQ) feedback are disclosed, where HARQ feedback operations by a receiving device may be modified. A receiving device may receive a data transmission. The receiving device may evaluate a condition for determining how to provide HARQ feedback in response to the data transmission. The receiving device may modify a HARQ feedback operation based at least in part on the condition. Modification of HARQ feedback operations may include turning off HARQ feedback, excluding negative acknowledgment (NAK) reporting, or excluding acknowledgement (ACK) reporting.

Abstract: A high power electrical connector is provided for transmitting electrical signals from a pair of cables, such as high current capable cables, to an associated member, such as a dash panel. The high power electrical connector includes an insulative housing and a pair of contact path assemblies therethrough for transmission of the electrical signals. The cables can be rotated relative to the housing and rotated relative to each other via the contact path assemblies. Ground path assemblies are also provided for grounding the cables. The cables can each be rotatable relative to a portion of the respective ground path assembly.

Abstract: Techniques are described for wireless communication. One method includes winning a contention for access to an unlicensed radio frequency spectrum band, transmitting a request message upon winning the contention for access to the unlicensed radio frequency spectrum band, and receiving a response message over the unlicensed radio frequency spectrum band. The request message is transmitted by a user equipment (UE) on an enhanced physical random access channel (ePRACH) or shortened ePRACH (SePRACH), to access a cell that operates in the unlicensed radio frequency spectrum band. The response message is received in response to transmitting the request message, and the request message may be transmitted irrespective of whether a base station has gained access to the unlicensed radio frequency spectrum band.

Abstract: Methods, systems, and devices for wireless communication are described. A receiving device may detect a signal associated with low latency transmissions and decode a non-low latency communication accordingly. The receiving device may receive an indicator from a transmitting device that indicates where and when low latency communications occur. The indication may specify frequency resources or symbols used by the low latency communication. The indicator may be transmitted during the same subframe as the low latency communication, at the end of a subframe, or during a subsequent subframe. The receiving device may use the indicator to mitigate low latency interference, generate channel estimates, and reliably decode the non-low latency communication. In some cases, the interfering low latency communication may occur within the serving cell of the receiving device; or the interfering low latency communication may occur in a neighboring cell.

Abstract: Methods, systems, and devices for wireless communication are described. A wireless system utilizing one or more time-division duplexing (TDD) configured carriers may utilize a dual transmission time interval (TTI) structure (e.g., at the subframe level and symbol-level). The symbol level TTIs may be referred to as low latency (LL) TTIs, and may be organized within LL subframes. A LL subframe may be a subframe that is scheduled for transmissions in one direction (e.g., uplink or downlink, according to a TDD configuration) and may include multiple LL symbols scheduled for both uplink (UL) and downlink (DL) transmissions. Guard periods may be scheduled between adjacent LL symbols that have opposite directions of transmission to enable user equipment (UEs) to transition from receiving mode to transmit mode (or vice versa). The LL subframes may be transparent to receiving devices that do not support LL operations.

Abstract: Certain aspects of the present disclosure provide techniques that may be used for low latency communications. For example, aspects allow a single group acknowledgement to be used to acknowledge a plurality of low latency transmissions. An exemplary method generally includes receiving, from a base station, a plurality of downlink channel transmissions, wherein each of the downlink channel transmissions is sent using a first transmission time interval (TTI) that is reduced relative to a legacy TTI and providing, in a single uplink channel transmission sent using a second TTI that is larger than the first TTI, a group acknowledgement indicating whether or not the downlink channel transmissions were successfully received by a UE.

Abstract: Techniques for handling Channel State Information (CSI) for ultra low latency (ULL) in Long Term Evolution (LTE) devices are presented. For example, an example method of reporting CSI to a network entity is presented. Such an example method may include detecting a CSI reporting trigger for reporting CSI to the network entity and identifying, based on detection of the CSI reporting trigger, a subframe region for which the CSI is to be generated. In an aspect, the subframe region is included in a plurality of subframe regions, where each subframe region of the plurality of subframe regions includes at least one symbol of a subframe. In an additional aspect, the example method may include generating the CSI based on the subframe region and transmitting the CSI to the network entity.

Abstract: Various aspects described herein relate to managing ultra low latency (ULL) communications over a plurality of component carriers (CC). A configuration for aggregating a set of CCs can be received, wherein the set of CCs includes at least a primary cell and a secondary cell. Based on the received configuration, at least the primary cell can be communicated with for legacy communications, wherein the legacy communications are based on a first transmission time interval (TTI) having a first duration. Based on the received configuration, the primary cell and the secondary cell can be communicated with for ULL communications, wherein the ULL communications are based on a second TTI having a second duration that is less than the first duration.

Abstract: Various aspects described herein relate to wireless communications, including generating a waveform including a combined reference signal and control data signal, the reference signal and the control data signal being phase offset from one another in the waveform, and transmitting the waveform on one resource block in a transmission time interval having a duration that is less than a subframe.

Abstract: Various aspects are described relating to wireless communications of a second type of traffic data for small data transmissions. A first indication of control channel resources can be received from a network entity, wherein the control channel resources are defined by a radio access technology to include control data associated with a first type of traffic data. A control channel can be received from the network entity over the control channel resources, wherein the control channel includes a second type of traffic data, wherein the second type of traffic data includes a comparatively smaller data payload than the first type of traffic data. The second type of traffic data can be decoded from the control channel without decoding control data from the control channel.