Now, I'm not sure (I don't know PoE in detail)
if I can use every
PoE-Switch.
No you can't.
The nanoBTS are not fully PoE compliant. For example they didn't work
with my Netgear GS724TP or GS748TP.
I searched in Internet and I found a Netgear FS108P.
It's cheap and it
will be enough for us. Can I use it with our BaseStation or have I to
use the power supplier of the BaseStations, too?
The netgear FS108P is a switch that's known to work with them. I use it myself.
Sylvain