Pass the device's hardware IDs through modem creation and use them
when calculating the device's identifier. Add a bunch of testcases
for real hardware to ensure we don't break the device ID in the
future unless we really want to.
Like UMTS vs. GSM, EVDO and 1x are separate networks and technologies
and have separate registration state. You can even be roaming on
EVDO while in your home 1x network. Handle that.