The link to the paper provide more detail. The basic idea is to use the FM radio RDS sub-channel as a sort of control plane or control channel. One of the thing

The link to the paper provide more detail. The basic idea is to use the FM radio RDS sub-channel as a sort of control plane or control channel. One of the things that differentiates LTE for example from 802.11 (WiFi) is that LTE has a control channel that coordinates the activities, when to transmit an on which channel via a control plane and hence achieves a higher spectral efficiency. Wifi uses CSMA/CD to sense and detect collisions. But sensing when they happen is not as good as just avoiding it all together. But to do that you need a control channel. The idea of using something as ubiquitous as the RDS sub-channel as a control channel has a lot of potential applications beyond Wifi, it could also be used for white space control to open up vast amounts of un-used spectrum potentially.