There really is no relationship. What you'll see is a device (like a radio transceiver) that will do a certain amount of bandwidth over the wireless link,
On the other side of our hypothetical "black box" transceiver, you'll get some flavor of standard interface; either an Ethernet/Fast Ethernet/Gig Ethernet or (a little closer to your question) a standard serial interface that'll probably be presented on a v.35 / Winchester connector.
That interface will (probably) be a DCE interface (or maybe several), just like a CSU/DSU (because it probably is that or something similar).
The "black box" will do the signal conversion from serial / V.35 into whatever signaling it uses to make the wireless transmisssion.
In the case of a traditional microwave radio, it was fairly common for them to handle up to three DS3s (45 Mbps each).
So what I'd expect is that if you had a radio system that could handle ~2 Mbps, you'd probably have a single V.35 interface that'd handle a T1/DS1 or E1.
If you had a radio that could handle 1.2 Gig of data wirelessly, then I'd expect a GigE inerface, or perhaps one or more OC3, or an OC12.
There are a variety of wireless systems in practically all bandwidth sizes, on just about any chunk of the RF spectrum, up to and including light (LASER - see the Canon Cannobeam).
Once the wireless bandwidth is deterined, then the router-side interface will be appropriate for that kind of bandwidth.
Good Luck
Scott
