> Perhaps they should also ask: if GPS is down in an area, do the cell towers continue to operate? If the towers are uniquely identified, and are geo-located a

> Perhaps they should also ask: if GPS is down in an area, do the cell towers continue to operate? If the towers are uniquely identified, and are geo-located accurately, it could be possible to triangulate your position even if they are not operational from a make-a-phonecal perspective. They just have to perhaps keeps shouting "I'm here!". Perhaps they'd at least need a semi-accurate time source? (Like a local rubidium clock, or at least NTP/PTP over a fibre backhaul.) On the other hand smartphones can geolocate themselves decently from Wifi AP signals, and those tend to not have timestamps with-in the broadcasts.