You would connect it to the AUX port like any modem. The only difference could be that you dial a number provided by the wireless provider (using ATD instead of ATDT!) and set up any initial chat scripts to put in an appropriate initialization string.
Alternatively, it looks like you can set the modem up as a dedicated connection, in which case you can just set the async port to "async mode dedicated" provided that the modem was provisioned to have a permanent connection and act as a PPP Server.
I would be inclined to set ip up as a permanent connection instead of an on-demand one. Much simpler process.
