Techniques are described for wireless communication. One method of wireless communication includes receiving, at a first user equipment (UE), a first communication over a shared radio frequency spectrum band from a first base station. The first communication includes a pre-grant communication associated with a downlink transmission or a grant of uplink resources associated with an uplink transmission. The method further includes determining, based at least in part on receiving the first communication, whether a channel reservation signal is detected over the shared radio frequency spectrum band; and transmitting a second communication over the shared radio frequency spectrum band, to the first base station, based at least in part on the determining. The second communication includes an approval of the downlink transmission or the uplink transmission.