in addition to what the others said...
Wired or moca connection is required on the roamio if you are going to hookup a mini (also wired or moca) later on.
Roamio Pro, wired ethernet
Mini using MOCA (from the Pro)
on Cablevision Raritan Valley system (Central NJ)
w/ Cisco PKM803 CableCARD on firmware 188.8.131.521
*** 2013 newbie to Tivo ***