A method of a base station (BS) to implement a listen-before-talk (LBT) protocol is provided. The method includes generating for transmission at least one of a discovery reference signal (DRS) or a data signal. The method also includes initiating an LBT protocol based on a single sensing interval to access a channel and transmit the DRS in contiguous orthogonal frequency-division multiplexing (OFDM) symbols. The method further includes initiating an LBT protocol with random back-off to access the channel and transmit the data signal, where a back-off counter value of the LBT protocol with random back-off does not decrement when the DRS is transmitting in the channel.