GNSS timing dependency

node

The dependency almost nobody counts. A GNSS receiver solves for time as well as position, which makes a cheap antenna on a rooftop an accurate atomic clock — and that turned out to be the service the wider economy actually built on. Mobile network base stations use it to keep transmissions from interfering; electricity grids use it to timestamp phasor measurements across hundreds of kilometres; financial venues use it to sequence orders and satisfy regulatory timestamping requirements; broadcast, data centres and industrial control systems use it to keep distributed clocks aligned. Because the signal is free, unauthenticated and arriving from twenty thousand kilometres away at a power level below the ambient noise floor, it is also easy to jam and easy to spoof, and the systems depending on it frequently have no independent holdover. A 2017 study prepared by London Economics for the United Kingdom estimated the cost of a five-day national GNSS outage at several billions of pounds — an estimate whose value is less in its precision than in demonstrating that the exposure had never previously been priced at all. Not a place.

A node is not a place. Drawing it on a map would assert something about the world that no stored fact supports.