Abstract: Techniques are described for wireless communication. One method includes identifying a transmission time interval (TTI)-level control region, where the cascaded control region includes a TTI-level common control region and a TTI-level UE-specific control region, and where the TTI-level common control region has a pointer to a location of the TTI-level UE-specific control region; and demodulating at least one of the TTI-level common control region and the TTI-level UE-specific control region. Some techniques enable control information in a first region to point to a second region that includes additional control information. Some techniques enable two-stages of control. Semi-persistent scheduling/prescheduling control may be configured to cause an entity to refrain from demodulating one of the stages of control.

Abstract: An access node may provide synchronization information to a UE. The access node may further provide one or more information blocks, which may include basic network configuration information. Based on the synchronization information and/or the information block(s), the UE may transmit a message to the access node that includes a random access preamble, an identifier of the UE, and/or a buffer status report. Based on the message from the UE, the access node may determine that the UE should remain active and, therefore, may transmit a response to the first message to the UE indicating that the UE should remain active. Thereafter, the UE may receive a connection setup or connection reconfiguration message. The connection setup or reconfiguration message may be received from the same or different access node from which the UE received the synchronization information and/or the one or more information blocks.

Abstract: A method, an apparatus, and a computer program product for wireless communication are provided in connection with enabling distributed frequency synchronization based on a fastest node clock rate. In one example, a first UE is equipped to determine that a fastest clock rate is faster than an internal clock rate of the first UE by more than a first positive offset, and adjust the internal clock rate based on the determined fastest clock rate. In an aspect, the fastest clock rate is associated with a second UE of one or more other UEs from which synchronization signals may be received. In another example, a UE is equipped to obtain GPS based timing information, adjust an internal clock rate based on the GPS based timing information, and transmit a synchronization signal at an artificially earlier time in comparison to a scheduled time of transmission associated with the adjusted internal clock rate.

Abstract: Methods, systems, and devices are described for determining a monitoring schedule for device-to-device (D2D) synchronization signals. A synchronization cycle may be determined that includes a plurality of monitoring periods. The monitoring periods may be a time between at least two start times of sequential D2D synchronization signals to detect at least one of the D2D synchronization signals. Sub-monitoring periods may be determined based on the duration of the monitoring periods. The sub-monitoring periods may have a cumulative duration the same as the duration of the monitoring period and be scheduled to occur during different monitoring periods of the synchronization cycle.

Abstract: Methods, systems, and devices are described for device-to-device (D2D) wireless communication. A device may transmit an initiation message to a base station indicating that the device desires to initiate a D2D communication session. The device may then receive a response from the base station that includes parameters for configuration of the D2D session. When it has data to send to another device, the device may transmit buffer status report (BSR) to the base station. The base station may respond with a grant of D2D scheduling assignment (SA) configured according to the previously sent parameters. For example, the message may be scrambled with a D2D temporary identity sequence. In some cases, the device may transmit a group identification (ID) code to the base station, and the group ID may be associated with an index, so an SA for that group can be reference by index.

Abstract: Methods, systems, and devices are described for coordinating a device to device (D2D) hopping scheme with a wide area network (WAN) hopping scheme. In one aspect, a method may include identifying, by a base station, a WAN frequency hopping scheme. The base station may coordinate a D2D frequency hopping scheme a D2D enabled user equipment (UE) with the identified WAN frequency hopping scheme, and communicate the D2D frequency hopping scheme to the D2D enabled UE. In one aspect, the D2D frequency hopping pattern may apply to retransmissions between two D2D enabled UEs. Another method may include receiving, by a D2D enabled UE, a D2D frequency hopping scheme from a base station, where the D2D frequency hopping scheme is coordinated with a WAN frequency hopping scheme. The D2D enabled UE may transmit at least one message to a second D2D enabled UE according to the D2D frequency hopping scheme.

Abstract: Methods, systems, and devices are described for direct device-to-device (D2D) communications in a subframe on a channel in an unlicensed radio frequency spectrum band. A user equipment (UE) may perform a listen-before-talk (LBT) procedure on the channel in the unlicensed radio frequency spectrum band. The UE may identify a time period between a completion of the LBT procedure and a boundary of a second subframe. The UE may transmit a Wi-Fi preamble and a variable length message on the channel during the identified timer period. The variable length message may include a duration that is time aligned with the boundary of the second subframe.

Abstract: Methods, systems, apparatuses, and devices are described for predicting an automatic gain control setting for long range discovery in a peer-to-peer network. In one configuration, an energy of each resource of a first set of resources may be estimated. A total energy of a second set of resources used for long range discovery in the peer-to-peer network may be predicted. The predicted total energy may be based at least in part on the estimated energy of each resource of the first set of resources. An automatic gain control setting for the second set of resources may be predicted based at least in part on the predicted total energy.

Abstract: A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus may be a UE. The UE determines timing information associated with a synchronization signal to be transmitted. The timing information includes a hop count and a reliability indicator associated with the synchronization signal. The reliability indicator is independent of the hop count and indicates one of reliable or unreliable. The UE broadcasts the timing information with the synchronization signal. The hop count may be a number of hops the synchronization signal is from a base station synchronization signal received from a base station.

Abstract: Methods, systems, and devices are described for determining pathloss. A transmitter may send a reference signal to receivers associated with broadcast transmissions. The receivers participating in the broadcast transmissions that receive the reference signal at a pathloss greater than a predetermined pathloss value may send a response to the reference signal. Receivers that receive the reference signal at a pathloss less than the predetermined pathloss value may not send a response. The pathloss may be determined based on whether a response is received. The transmitter may then transmit signals for the broadcast transmission at a power level determined based on the pathloss value.

Abstract: A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus may include memory and at least one processor, coupled to the memory, configured to determine a transmission condition associated with communication over a wireless channel. The processor may be configured to select a set of open-loop power control parameters of at least two sets of open-loop power control parameters based on the transmission condition. The processor may be configured to transmit over the wireless channel with a power based on the selected set of open-loop power control parameters. The apparatus may be a wireless device, such as a user equipment (UE). The open-loop power control parameters may be received from a base station, such as a node B or an evolved Node B (eNB).

Abstract: A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus receives one or more D2D broadcasts in a set of subchannels of a channel. In addition, the apparatus broadcasts in at least one subchannel of the channel information indicating a subset of the set of subchannels. The one or more D2D broadcasts may include a first set of broadcasts that includes control information and a second set of broadcasts that includes data traffic. The broadcasted information may be control information. The apparatus may determine a signal strength of each of the one or more D2D broadcasts received in the set of subchannels. The broadcasted information may further include the determined signal strength for each subchannel in the subset of the set of subchannels.

Abstract: A procedure to select a UE as a relay between a machine-type communication (MTC) device and a base station is desired to improve communication between the MTC device and the base station. The apparatus may be a machine-type communication user equipment (M-UE). The apparatus transmits, to one or more user equipments (UEs), an access request to request access to a base station through one or more of the one or more UEs as a relay. The apparatus receives an access request response from the base station, the access request response including selection information about selection of at least one of the one or more UEs as a relay between the M-UE and the base station.

Abstract: A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus determines K subsets of a resource pool. Each subset includes K grid elements. Additionally, each grid element includes at least K sub-elements. The apparatus selects one subset of the K subsets of the resource pool. Additionally, the apparatus transmits a message using K sub-elements of the selected subset.

Abstract: A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus receives information indicating a number of physical resource blocks (PRBs) from a base station. Additionally, the apparatus determines a discovery resource of a plurality of discovery resources for device-to-device (D2D) discovery. In some examples, a size of the discovery resource being based on the received information indicating the number of PRBs. The apparatus also transmits a discovery signal on the discovery resource. In another example, the apparatus receives information indicating a number of physical resource blocks (PRBs) from a base station. Additionally, the apparatus also determines a plurality of discovery resources for device-to-device (D2D) discovery. In some examples, a size of each of the plurality of discovery resources being based on the received information indicating the number of PRBs.

Abstract: Certain aspects of the present disclosure relate to a technique for multiplexing downlink control information (DCI) signals for multiple user equipments (UEs) at an aggregation level (AL) by coding the DCI signals together in a control channel and transmitting the control channel. In an exemplary method, a BS multiplexes a first plurality of downlink control information (DCI) signals for a first plurality of user equipments (UEs) at a first aggregation level (AL) coded together in a first control channel and transmits the control channel.

Abstract: The present disclosure enables the assignment of multiple semi-persistent resource assignments at the same time for use in V2V communications. In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a UE (e.g., a vehicle). The UE may determine at least one resource pattern required for V2V communications. The UE may also send assistance information for the at least one resource pattern to a base station. Further, the UE may receive, from the base station, a response associated with the at least one resource pattern. In an aspect, the response may include an index of approved resource patterns. Further still, the UE may receive, from the base station, an activation grant for a resource assignment for the at least one resource pattern. In an aspect, activation grant may include the index of approved resource patterns being activated.

Abstract: In one aspect of this disclosure, control information and data are carried in the same subframe in order to reduce control overhead. A method, an apparatus, and a computer-readable medium for wireless communication are provided. The apparatus may be a first UE. The first UE determines a data block to be transmitted to a second UE. The first UE determines a first resource in a subframe for carrying the data block and determines a second resource in the subframe for carrying control information associated with transmitting the data block. The first UE transmits the data block and the control information to the second UE in a device-to-device communication channel on the determined first and second resources, respectively.

Abstract: Techniques for scheduling assignment (SA) transmissions in device-to-device (D2D) communications are described. A D2D user equipment (UE) may use a block of time resources for SA transmissions. A D2D UE may transmit an SA transmission relatively quickly after determining that D2D data is to be transmitted to another D2D UE, relative to having to wait for specified time resources to send an SA transmission. The D2D data may then be transmitted following the SA transmission, reducing latency for transmission of the D2D data. It may be desirable for vehicle-to-vehicle (V2V) transmissions to have a relatively low latency to provide data from one vehicle to another with sufficient time for a vehicle to take action while moving at relatively high rates of speed.

Abstract: A method, an apparatus, and a computer program product for wireless communication are provided. The apparatus determines that a first external timing source timing signal is available at a first UE. The apparatus also synchronizes the first UE using the first external timing source based timing signal when the first external timing source timing signal is available. Additionally, the apparatus transmits a synchronization signal indicating that the first UE is synchronized using an external timing source timing signal.