US Patent 10129870 Separation of control and data subbands in unlicensed spectrum

A wireless device may identify a first subband in an unlicensed radio frequency spectrum band used to communicate control traffic. The wireless device may identify a second subband in the unlicensed radio frequency spectrum band used to communicate data traffic. The first subband and the second subband may be different. The wireless device may reserve the first subband for a first duration of time for a plurality of wireless devices. The reservation may be based at least in part on an enhanced self-clear-to-send (self-CTS) transmitted over the first subband.