Like Skip said, the cell freqs are all a form of digital that can not be heard on scanners, even if the freqs themselves were in your radio. (They are not the same format of digital as digital scanners have...)
While the original cell freqs (869-894) are still used, there are other cell bands as well, mostly up around 1900 MHz., outside the range of most scanners, but again, in formats that even the best scanners can not hear.
Most scanners do have other ranges that they do not cover. Most cover the classic scanner bands, usually some derivative of 25-54, 108-174, 406-512 and 806-960 (minus the 869-894 and 824-851 cell ranges). Better scanners cover the Mil Air band of roughly 225 to 406 and some radios cover more esoteric bands like 72-76 (mostly industrial comms and data) or extend the 800/900 bands to cover the 700 MHz range and up to 1300 for the ham band there.
The stuff in between these ranges is usually of little interest to scanner listeners, such as TV channels, FM broadcast or unmonitorable (cell phones).
There are a couple scanners with "No Gaps", such as the venerable PRO2004/5/6 that covered 25-520 and 760-1300 minus the cell phone ranges (easily restored). Wildly popular, these worked well over the entire range of freqs, and the only stuff that was missing was 520-760, which is part of the TV bands.