Question on a Paver Patio
If you are using the most common type of paving stones (less than 10" in all horizontal directions), the recommended method is to put a 1" sand (concrete sand) over a compacted base (Class 5 is the local standard) that is graded to releflect the slope you want for drainage. After that the pavers are set, edge restraints installed and them masonry sand should be vibrated to even out the surface and get the sand into the the tight joints that provide the interlock and stability.
the frost depth is really not a major factor if you can provide drainage through a sand layer to make the lower moisture uniform. Highways are not bult much different for the loacal frost level if the lower soil has uniform moisture contents since the road, sidewalk or pation will lift and settle uniformly. People in Minnesota and other areas build structures on top of 4' or 5' deep concrete footings, but no roads need to have a 4' deep foundation, because heaving and settlement is relative.
Look at the sites for Anchor Block, Borgert Concrete and Versalok/Willow Creek for details. They are probably your local suppliers depending on your location or the dealer sites.