LISTEN BEFORE TALK FOR LTE DIRECT ON UNLICENSED RADIO FREQUENCY SPECTRUM BAND

摘要

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.