Man, I saw a presentation on Iridium when I was at Motorola in the early 90s, maybe 92? Not a marketing presentation - one where an engineer was talking, and had done their own slides.

What I recall is that it was at a time when Internet folks had made enormous advances in understanding congestion behavior in computer networks, and other folks (e.g. my division of Motorola) had put a lot of time into understanding the limited burstiness you get with silence suppression for packetized voice, and these folks knew nothing about it.