Welcome to the OptoForums! I'm no expert but 1 to 5 miles sounds pretty far, especially since I've heard that rule-of-thumb our 802.11b/g devices have a similar range to something like an iPAD's wifi (vs. cellular).
If we look at the spec for a [SNAP-PAC-S2-W, for example, I see lots of numbers (including 802.11b/g), but what does that all mean? If I were to believe the [URL="http://en.wikipedia.org/wiki/IEEE_802.11"]Wikipedia entry](http://www.opto22.com/site/pr_details.aspx?cid=1&item=SNAP-PAC-S2-W) about 802.11b/g, their outdoor range is 460 feet. (That sounds far-ish too and of course will vary depending on many factors.)
I've also heard it's possible to extend the range of our wireless devices by replacing the standard screw-on antennae with a bigger one. Still, I think the ranges you're talking are outside normal "wifi" type ranges.
Perhaps a good place for a cellular modem? Here's another post about those:
Hope that helps!