[Mod note: Commenter works for Videofied]
Ross,
The Videofied panel communicates with both/either/or Ethernet or Cellular from the panel to the Central Station. To communicate over Ethernet the panel must be powered. Because Ethernet requires power, if the panel is installed to operate ONLY on batteries, then it will communicate over Cellular. THe modem is "off" until an alarm event.
In any case, the wireless MotionViewer cameras use our encrypted 900MHz RF and not Wi-Fi. This is the same frequency that is used by first responder radios for the same reason. Police want to be able to communicate when they enter buildings and 900MHz actually does a good job of penetrating building materials.