Netflow Analyzer 7, Radius and dynamic IP tracking

Have question about tracking dynamic ip traffic. Here is currently how we are setup.

We have two static pool subnets, 2 dynamic pool subnets, Netflow enable and tracking, netflow analyzer up and running. Customers radios use a radius server to authenticate through.

The problem I forsee us having as far as tracking bandwidth and such is that the dynamic ip's will change and will be assigned to someone else and thus tracking will be useless for that person as the ip will belong to someone else.

I know NFA 7 has a radius section. The radius server tracks the ip and the user authenticated to that ip. Is this the purpose of the radius section in NFA 7 or is there another way to get this tracking to work the way we are using it.

I know another way to do it would just be to assign everyone a static but that isn't going to happen at this point.