Methods, systems, and devices for wireless communication are described. A base station may identify a transmission opportunity duration and an allocation for downlink and uplink transmissions, then broadcast a channel reservation request transmission. The broadcast may be sent using unlicensed radio frequency spectrum over a channel that includes multiple-sub-bands. The channel reservation transmission may include the identified duration, allocation, and a channel state information (CSI) request. User equipments (UEs) may receive the broadcast, and respond with a channel reservation response transmission that includes a CSI report, a transmit identity, or an interference threshold indicator. In some cases, some or all of the UEs may transmit a sounding reference signal (SRS) in response to an SRS request that is broadcast by the base station. The base station may schedule uplink and/or downlink transmissions to at least a subset of the multiple UEs based on the channel reservation response and/or SRS.