The chronicles of reversing the Iridium pager system.
The Iridium satellite system provides voice and data coverage to satellite phones, pagers and integrated transceivers over Earth's entire surface. It was built by Motorola over 15 years ago, and parts of it remain unchanged to this day. Iridium pagers are similar to other pager systems from that time (they are receive-only devices) with the benefit that they will work anywhere on earth. Additionally they work on a receiver-pays subscription model, and due to their age are probably not using cryptography. Broadcasting messages all over the world sounds interesting enough to take a closer look. As Iridium is a proprietary system, documentation is scarce and hard to come by. But with the rise of software defined radio we can take a peek at what happens over the air...