The Iridium constellation is 485 miles above. I've used it for both voice and data at sea via a motorola handset. Voice was very responsive with no delay, though the compression was very apparent. Data is painfully slow at 2.4 kbps. We needed to use a specialized email client that compressed email, handled the duplex connection, and recovered from errors very gracefully.
I'm curious the reason for such slow data too. Looks like the design was optimized to maximize the number of voice connections for a minimal number of satellites. Combined with the age of the design (first launched in '97) gives pretty poor data connections.
I'm curious the reason for such slow data too. Looks like the design was optimized to maximize the number of voice connections for a minimal number of satellites. Combined with the age of the design (first launched in '97) gives pretty poor data connections.