Iridium Satellite Time and Location (STL)
A timing and positioning signal broadcast from Iridium's low-orbit satellites that is about 1,000 times stronger than GPS-style signals, works indoors, and helps data centers and 5G base stations keep time if GPS fails or is jammed.
Why it matters
Much of modern infrastructure, from 5G base stations to data centers, takes its clock from GPS, and GPS signals are weak enough to be jammed or faked with cheap equipment. A much stronger, separately sourced signal gives those systems a second, harder-to-attack reference.
How the technology works
STL rides on the Iridium constellation of crosslinked satellites in low Earth orbit. Iridium says the signal is about 1,000 times more powerful than GNSS signals, so receivers can pick it up indoors and keep working during regional GNSS outages.
It is meant to complement and protect GPS rather than replace it. Iridium expects the business to exceed $100 million a year in service revenue by 2030.
Sources
Updated Oct 22, 2026 · How we source facts · Suggest a correction