Actually, assuming the documentation and type naming is accurate and that it behaves the same way in all devices, this is telling you the type of the network you are connected to, not the device type nor the SIM type.
You might for example have a 3G capable SIM (or 4G now...) but be in a network coverage area which only supports GPRS or EDGE etc.
The TelephonyManager flag simply tells you what your current network connectivity is.