Unless something has changed in the last couple of months, you cannot configure a John Deere receiver to run from CORS.  John Deere uses a proprietary message stream.  To my knowledge the only way to use a CORS station with a John Deere system is run it from a Leica MOJORTK receiver.  I think Leica has the CORS support released now (or they will soon).

You cannot do voice an data at the same time, so you cannot receive calls while the phone is used for guidance.  You can surf the internet while the correction signal is steaming.  We have dedicated phones for our guidance systems.  We use them for internet at the same time.