Wireless ISP setup.

Hello everyone,
I need a few suggestions regarding setting up an Wireless ISP.

Currently we are distributing bandwidth to our customers by using
DSL modems which can be used upto a distance of 5KMs.

We want to replace the present set up(the last mile connectivity to
the users)by using wireless equipments. Can any body give some pointer
in this regard ? Has any body used D-Link products in such kind of
environment(ISP) ?

Thanks and regard
baruah