Does anyone know of a mobile broadband which provides a static (as opposed to dynamic) external IP address?
Thanks for your question Subligaria.
I could be wrong but I don't think there is a mobile provider that is able to provide a static IP. IP addresses are, to a degree, specific to a geographic area. An address that you would be given in New York wouldn't be available in Los Angles because the local address pools they draw from are different.
If you have a need to display a consistent IP for some specific purpose, a VPN connection to somewhere that has a static IP should do the trick though it will slow the connection somewhat. The amount that it slows the connection would be dependent on the connection you have at the time you connect to the VPN and also the speed of the VPN servers connection.