Abstract: Methods, systems, and devices for wireless communication are described for synchronization for wideband coverage enhancement. A user equipment (UE) may receive a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) in a subframe. In one example, the SSS may be received in a symbol that is after a symbol in which the PSS is received, and after a set of symbols in which a set of other synchronization signals is received. In another example, the PSS may be received in each of a first plurality of consecutive symbols, and the SSS may be received in each of a second plurality of consecutive symbols, wherein the second plurality of consecutive symbols is after the first plurality of consecutive symbols within the subframe. The UE may synchronize with a base station based at least in part on the PSS and the SSS. Numerous other aspects are provided.

Abstract: In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. In one configuration, the apparatus may receive, from a base station, first information associated with one or more resources allocated for at least one PRACH transmission. In one aspect, the one or more resources may be allocated in an unlicensed spectrum. In another aspect, the one or more resources may be allocated based on a multi-tone PRACH bandwidth. The apparatus may also receive second information associated with a frequency hopping configuration from the base station. In one aspect, the frequency hopping configuration may be associated with at least one of the one or more allocated resources or the multi-tone PRACH bandwidth. The apparatus may transmit, to the base station, the at least one PRACH transmission using the one or more allocated resources within the multi-tone PRACH bandwidth and the frequency hopping configuration.

Abstract: Methods, systems, and devices for wireless communication are described for synchronization for wideband coverage enhancement. A user equipment (UE) may receive a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) in a subframe of a frame. In one example, the PSS may be received in each of a first plurality of consecutive symbols of the subframe. In another example, the SSS may be received in each of a second plurality of consecutive symbols of the subframe, wherein the second plurality of consecutive symbols is after the first plurality of consecutive symbols within the subframe. The UE may synchronize with a base station based at least in part on the PSS and the SSS received in the subframe. Numerous other aspects are provided.

Abstract: Methods, systems, and devices for wireless communication are described that provide for a base station to use frequency hopping for cell acquisition according to a frequency hopping pattern. The frequency hopping pattern may include a set of anchor channels and a set of non-anchor channels used by a base station to communicate with wireless devices. The base station may occupy an anchor channel more often than a non-anchor channel and may transmit acquisition signals using the anchor channel. The anchor channel may also be used by the base station and a user equipment (UE) to exchange paging information, positioning information, random access resources, location of other channels, etc.

Abstract: In order to conserve power resources for low complexity UEs, a base station may apparatus dynamically adjust a bandwidth configuration of a UE or the base station and communicates with the UE according to the dynamically adjusted bandwidth configuration. The communication may be narrowband communication. A UE may apparatus dynamically adjust a bandwidth configuration of the UE and communicates with a base station based on the dynamically adjusted bandwidth configuration. The dynamically adjusted bandwidth configuration may correspond to a function performed by the UE.

Abstract: Described techniques provide for switching a user equipment (UE) between different coverage enhancement (CE) modes, such as between a non-CE mode and a CE mode. A UE may determine that a CE mode switch is to be performed and may initiate the mode switching. The UE may compare signal qualities of signals from one or more base stations against one or more threshold values and determine that a switch from a CE mode to a non-CE mode, or from a non-CE to CE mode, is to be performed. In some cases, a UE may be in idle mode and switch between CE modes, or may perform a cell reselection to a different base station. In other cases, a UE may be in connected mode and may declare a radio link failure to initiate a mode switch. A base station may initiate mode switching based on radio link monitoring of UEs.

Abstract: In an embodiment, an apparatus (e.g., eNB) pages UEs on a shared communication. The apparatus obtains paging message(s) for transmission to UEs with different coverage levels. The apparatus transmits an extended common ePDCCH, followed by a paging ePDCCH, followed by repetitive transmissions of the paging message(s) over a plurality of PDSCH subframes. In a further embodiment, the apparatus obtains first and second sets of paging messages for transmission to different paging groups. The apparatus establishes non-overlapping POWs for the first and second paging groups to avoid a paging ePDCCH collision.

Abstract: Methods, systems, and devices for wireless communication are described. A user equipment (UE) may receive an uplink grant that conveys an indication of a multi-transmission opportunity (TxOP) grant. The UE may transmit, during a first TxOP, a first uplink transmission in one or more subframes in accordance with the multi-TxOP grant. The UE may transmit, during a second TxOP, a second uplink transmission in one or more subframes in accordance with the multi-TxOP grant.

Abstract: In an embodiment, an access point executes a Clear Channel Assessment (CCA) protocol to determine whether to begin transmission within a DRS Measurement Timing Configuration (DMTC) window. The access point transmits, based on a result of the execution, a multi-subframe DRS within the DMTC window, the multi-subframe DRS including a plurality of DRS subframes that each includes a plurality of symbols.

Abstract: Described techniques provide for transmission of synchronization signals using frequency hopping across a number of hopping frequencies in unlicensed or shared radio frequency spectrum. A base station may identify a set of hop frequencies for transmitting synchronization signals, and transmit synchronization signals using a hopping pattern over the hop frequencies. A user equipment (UE) seeking to identify the base station may monitor one or more of the hop frequencies to identify one or more synchronization signals on the hop frequency. A system timing may be identified in some cases, and one or more base station IDs may be identified. In some cases, a hop frequency may be monitored for a duration that may span the transmission of two or more synchronization signals of a particular base station, based on a periodicity of synchronization signal transmissions on each hop frequency.

Abstract: Techniques for wireless communication are described. One method includes assigning a downlink subframe that is a first occurring downlink subframe in a data frame; and transmitting an encoded control signal during a first transmission opportunity, the encoded control signal including a common portion for receiving devices, the common portion indicating a structure of the data frame, the encoded control signal further including a device specific portion for a specific receiving device, the device specific portion indicating uplink grants and downlink grants during the data frame for the specific receiving device, where at least the common portion of the encoded control signal is transmitted during the selected downlink subframe.

Abstract: Certain aspects of the present disclosure provide techniques for transmitting and receiving self-contained transmissions for enhanced machine type communications (eMTC) in unlicensed spectrum (eMTC-U). An exemplary method includes a BS determining, based on a listen before talk (LBT) procedure, that a first portion of unlicensed radio frequency spectrum is available for a frame, transmitting, on the first portion of the unlicensed radio frequency spectrum, a control channel indicating a frame format of the frame or a grant of the first portion of the unlicensed radio frequency spectrum for the frame, and communicating with a user equipment (UE) according to the frame format or the grant during the frame.

Abstract: A method and apparatus for wireless communication in the unlicensed spectrum between an eNB and UEs having different bandwidths, e.g., between a narrowband UE and a wideband eNB. A base station apparatus may perform a dual CCA procedure for a frame, wherein the dual CCA procedure comprises a first type of CCA procedure followed by a second type of CCA procedure when the first type of CCA procedure is unsuccessful. The apparatus may transmit during the frame when at least one CCA procedure of the dual CCA procedure is successful and may refrain from transmitting during the frame when both CCA procedures of the dual CCA procedure are unsuccessful. In performing the dual CCA procedure, the apparatus may perform CCA for a first period of time then perform eCCA for a second period of time following the CCA, when the CCA is unsuccessful.

Abstract: A method and apparatus for wireless communication in the unlicensed spectrum between an eNB and UEs having different bandwidths, e.g., between a narrowband UE and a wideband eNB. A base station apparatus performs an LBT procedure at a beginning of frames and transmits a plurality of repetitions of a transmission. When the plurality of repetitions span multiple frames and the LBT procedure is not successful for a first frame, the base station drops or postpones at least one repetition in the first frame until a second frame when the LBT procedure is successful. A UE receives the plurality of repetitions and may combine a plurality of repetitions across multiple frames. The UE may determine whether the base station drops the at least one repetition in the first frame or postpones the at least one repetition in the first frame until a second frame.

Abstract: A method and apparatus for wireless communication in the unlicensed spectrum between an eNB and UEs having different bandwidths, e.g., between a narrowband UE and a wideband eNB. A user equipment apparatus segments an uplink duration in each frame into multiple transmission units for each frequency, wherein a frame comprises an integer number of the transmission units. The apparatus transmits uplink communication based on the multiple transmission units, wherein each transmission unit comprises at least one on period and at least one off period corresponding to each of a plurality of frequencies, wherein during an on period the UE transmits uplink communication on the corresponding frequency and during an off period the UE refrains from transmitting uplink communication on the corresponding frequency. Each transmission unit may comprise multiple on periods and multiple off periods. The on/off periods may be configured by a base station or specified for each frame type.

Abstract: A method and apparatus for wireless communication in the unlicensed spectrum between an eNB and UEs having different bandwidths, e.g., between a narrowband UE and a wideband eNB. A UE apparatus transmits uplink transmissions in a plurality of transmission units and hops frequency bands in a first pattern across frames based on a base station hopping pattern. The apparatus may transmit uplink transmissions based on dual hopping patterns, and may hop in a second pattern across transmission units within the base station's channel occupancy within a frame. A base station apparatus may hop frequency bands in a first pattern across frames based on a base station hopping pattern, and may receive uplink transmissions in a narrowband from a UE in a plurality of transmission units within the frequency bands based on the base station hopping pattern.

Abstract: This disclosure includes methods, systems, and devices for wireless communication. A repetition of symbols may be used to increase a device's ability to synchronize and communicate using unlicensed spectrum. For example, a base station may schedule a frame that includes repetitions, in time or frequency, of a control or data signal. After performing a listen-before-talk (LBT) procedure, the base station may broadcast or transmit the frame to one or more devices, such as a user equipment (UE). For instance, the frame may include repetitions of a discovery reference signal (DRS), and be broadcast by the base station to enable synchronization by the UE. In other examples, the signal may include repetitions of a cell-specific reference signal (CRS), and a UE may identify a start of a transmission opportunity using the CRSs. Other signals, such as downlink control and shared channels, may be repeated within a frame in a similar manner.

Abstract: Methods, systems, and devices for wireless communication are described. A user equipment (UE) and base station may communicate using narrow band internet of things (NB-IoT) techniques or enhanced machine type communication (eMTC) in unlicensed spectrum. The UE may be an eMTC device or another device capable of communication without user direction. The UE may identify a geographic region and select a communication mode that is consistent with regulatory restrictions in that region. For example, in some cases, the communication mode may be based on using time division duplexing (TDD), using frequency hopping, or performing a listen-before-talk (LBT) procedure at the base station. A frame structure for TDD may include LBT subframes, uplink portions, downlink portions, and special subframes for switching. The base station may perform LBT procedures in the LBT subframes. If frequency hopping is enabled, a configurable number of TDD frames may be grouped into a hopping frame block.

Abstract: Methods, systems, and devices for wireless communication are described. Resources for narrowband communication in an unlicensed radio frequency spectrum band may be configured and allocated based on resource availability, regulatory constraints, and device capability or category. A narrowband wireless device, such as a machine type communication device or other relatively low complexity device, may communicate using one or more narrowband carriers, which may occupy between one tone and multiple resource blocks in an unlicensed spectrum band (e.g., any number of resources between one (1) tone and multiple resource blocks (RBs)). Different device types may thus be configured differently as they move between geographic regions. The base station may then communicate with the narrowband mobile device based on the resource allocation and the carrier configuration.

Abstract: Techniques for random access channel signaling on a shared communication medium are disclosed. A broadcast message including information associated with a Physical Random Access Channel (PRACH) may be transmitted and received on one or more subframes in a portion configured for downlink signaling. The broadcast message may comprise a contention type indicator, a timing advance indicator, or a combination thereof. The contention type indicator may indicate whether contention is in effect for transmission on the PRACH. The timing advance indicator may indicate whether an uplink transmission offset is in effect for transmission on the PRACH. Signaling over the PRACH may be transmitted and received on one or more subframes in a portion configured for uplink signaling.