A closed loop carrier sense multiple access multiuser request to send and clear to send handshaking system is provided to efficiently allocate licensed and unlicensed spectrum for a plurality of mobile devices and across different base stations and mobile network operators. A user equipment device can be connected to a base station device via a first frequency in licensed spectrum, and a second frequency in unlicensed spectrum. The air interface on the first frequency can then be used to coordinate physical and virtual carrier sensing on a second frequency among a plurality of user equipment devices. Moreover, carrier sensing results from a plurality of UEs can be reported a base station device via the first frequency in licensed spectrum. The base station device can then schedule multiple user multiple input, multiple output (MU-MIMO) transmissions to a plurality of UEs on the second frequency in unlicensed spectrum.