Methods, systems, devices, and apparatuses are described for a listen-before-talk (LBT) mechanism. A wireless node, e.g., a base station, may determine that a channel is available based on completing a clear channel assessment (CCA) procedure. The wireless node may be associated with a first operator. The wireless node may transmit a first message on the channel in a subframe based on the CCA procedure. The first message may include a header portion that precedes a data portion. The first message may be time aligned with a second message transmitted from a second wireless node that is associated with the first operator.