15. A computer program product comprising: a tangible storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing 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.
16. The computer program product of claim 15 , wherein the method further comprises probing the spectrum band for a data transmission drift associated with the current working mode of the primary user, wherein the scheduling transmissions on the spectrum band is further responsive to the data transmission drift associated with the current working mode of the primary user.