More About Iridium…
IRIDIUM PRODUCT LIST       EXTERNAL ANTENNAS       DOCKING STATIONS       FLIGHTCELL PRO      

Iridium provides voice, SMS, and data service over the entire globe, including the polar caps. The only exceptions are countries that have requested that Iridium voluntarily block its service within all or parts of their borders (North Korea and sometimes northern Sri Lanka do not have service). Iridium operates a large number of low earth orbit (LEO) satellites spanning the globe in various polar orbits. An Iridium phone uses L-band frequencies so you must be in direct line-of-sight with an Iridium satellite in order make a call.

The ideal situation is to be on flat ground surrounded by no obstructions that block more than 15 degrees of elevation above the horizon. Mountains, trees, buildings or other obstructions may block some or all of the satellites causing brief periods without service. If there is an area nearby that is less obstructed, you may find it more effective to make Iridium calls from that location. Iridium phones are capable of making calls in most weather conditions. When you call a public switched telephone number (PSTN), your call is routed from satellite to satellite until it reaches the Iridium gateway in Arizona. From there it is routed to the final PSTN number. If during your call, the satellite moves behind an obstruction such as a mountain peak, your call can be passed to a different satellite, but often the call is unexpectedly terminated. Fortunately, the Iridium satellites are always moving, so if you lose signal another satellite should be along in a short time. Wait until your phone's signal strength indicator shows at least 3 bars of signal strength and dial again. Iridium uses aggressive voice compression so Iridium voice quality is only fair.