At an altitude of 4000 miles or less, it IS low latency if the path is just to the bird and back. Iridium’s problem is low throughput and if there is a latency issue, it’s due to the hardware, switching data between birds, terrestrial equipment and gateways, not its altitude. I’m aware of what Iridium is used for—more than just phone calls. Iridium is at almost 500 miles above the surface. A direct 1000 mile round trip via satellite is faster than a round trip on fiber from DC to Chicago (light in fiber travels at 66% of the speed of light in a vacuum)—but Iridium data don’t always take the shortest path getting to Hilo and Tempe.