The utilization rate of licensed spectrum is very low in the time domain, frequency domain and space domain, while the unlicensed band is overcrowded seriously.

This is no small thing; the standard for Wi-Fi was developed on unlicensed spectrum that had been considered "junk band", cluttered with low-intensity signals from microwave ovens and baby monitors.

In order to improve the spectrum usage of the up-band of fixed satellite service(FSS), an unlicensed access scheme is presented.