[OT] Fixed public IP address on aircard

[vu pham]

Does anyone know the procedure of how to get a fixed public ip address 
for an aircard ?

I need it for several aircards but just wasted too much time to look for it.

I know ATT has that option ( and expensive $500 for one IP ). The 
problem is I and my colleagues have talked to many different people from 
ATT and it seems no one understands what we want. One of them  asked me 
to go to an ATT store to order it. I called and the man there told me 
"Just go over here. We will do it. We know what you are talking about". 
Then I asked if I would purchase an aircard over there and they would 
assign IP address for me from the store. The answer is "No, your company 
technician will help you".

Anybody here knows how to get that ?

Thanks,
Vu