If so, my suggestion would be to run private IP across your whole network, /30 for each link from your core router to each base station, then allocate a private routed subnet to each base station for CPE's, use DHCP from the base to hand them out.
Once you get to that point, setup a bridge interface on your core router with another private subnet on it, whatever you want, then setup EOIP interfaces at the CPE going back to EOIP interfaces for each base on the bridge interface on the core router. Then using PPPOE from there deliver /32 public IP's straight to your CPE's and you have great control doing it that way.
There is a great presentation that covers this method pretty well, it's scalable and reliable.
some questions
1. How will it defait route via the pppoe? if the dhcp server gives out metric of 1?
2. Is much overhead with Eoip?
3. Can I encryped or should I use wpa of the radio layer
4. some bases are 4 - 5 hops away, I use ospf, would this be a problem?
1. How will it defait route via the pppoe? if the dhcp server gives out metric of 1?
Easy, just set the PPPOE interface to be the default route.
2. Is much overhead with Eoip?
Not too bad, as long as you have good gear you won't have an issue
3. Can I encryped or should I use wpa of the radio layer
You can encrypt with PPPOE if you want, but WPA between your AP and CPE may be better
4. some bases are 4 - 5 hops away, I use ospf, would this be a problem?
No problem, as long as you can route you can EOIP