VHF Omnirange (VOR)[1] is unlikely to be involved. VOR stations are not dependent on a network. All they need is power. It's 1950s technology. The big ring of antennas next to US 101 just north of SJC is a VOR.

[1] https://en.wikipedia.org/wiki/VHF_omnidirectional_range

Sorry, typo, I meant VHF (i.e. voiceband), of course. VORs are indeed for navigation, not communication. Updated.