8. A device comprising a processor configured to perform a method comprising: receiving information about an expected use of a spectrum band in a radio frequency spectrum, the expected use by a primary user; classifying the expected use of the spectrum band into at least two working modes, the classifying responsive to the information about the expected use; sensing the spectrum band to determine a current access pattern of the primary user; selecting one of the working modes as a current working mode of the primary user, the selecting responsive to the classifying and to the current access pattern of the primary user; scheduling transmissions on the spectrum band using a current schedule that is responsive to the current working mode of the primary user, the scheduling as a secondary user of the spectrum band; determining whether the current working mode of the primary user has changed; if the current working mode of the primary user has changed, re-performing the sensing, selecting, scheduling, and determining; and if the current working mode of the primary user has not changed, re-performing the scheduling and determining.
8. A device comprising a processor configured to perform a method comprising: receiving information about an expected use of a spectrum band in a radio frequency spectrum, the expected use by a primary user; classifying the expected use of the spectrum band into at least two working modes, the classifying responsive to the information about the expected use; sensing the spectrum band to determine a current access pattern of the primary user; selecting one of the working modes as a current working mode of the primary user, the selecting responsive to the classifying and to the current access pattern of the primary user; scheduling transmissions on the spectrum band using a current schedule that is responsive to the current working mode of the primary user, the scheduling as a secondary user of the spectrum band; determining whether the current working mode of the primary user has changed; if the current working mode of the primary user has changed, re-performing the sensing, selecting, scheduling, and determining; and if the current working mode of the primary user has not changed, re-performing the scheduling and determining. 11. The device of claim 8 , wherein the determining whether the current working mode of the primary user has changed is responsive to a bit error rate on the spectrum band.