Mobile technologies have come along way since the first mobile phones and portable two way radios.

Iridium was amongst the first to design a handheld mobile phone that uses satellites to communicate rather than the usual terrestrial base stations. This has now evolved into hybrid phones that can choose the best method for transmission. If no base stations are available, because there aren't any for example, then the phone uses the orbitting web of satellites to dial into the network.

Why would you need such a phone?

Well, imagine you are half way up a mountain, you injure yourself and need help, or you just want to give an update of your position and health. Maybe you need a weather schedule or when you reach the summit you just want to tell someone. With the satellite phone this is all possible.

Infact, it has been possible for sometime now. Inmarsat have had satellite telephones capable of doing this job for many years but the phones are not so small. They come in the form of a briefcase or nowadays a small laptop sized bag. But these terminals use geostationary satellites and require an antenna to be aligned and pointed at the satellite. Handheld comms does not because the user, you or me, would not expect to have to point our mobile phones in any particular direction and so the handheld satphones also have to work the same way. They look like slightly larger mobiles. They have the same keypad and display layout and they dial in the same manner too.

So how does the handheld system work?

The Iridium Satellite System has complete coverage of the Earth through a constellation of 66 low-earth orbiting (LEO) satellites. The handsets communicate with the satellites which in turn communicate with each other routing and switching your call across the globe to a ground based 'Gateway' receiving station.

Click here for the Iridium Website Overview Page which provides much more information