How does a Satellite Phone work?

Introduction

The operation of a satellite phone is relatively similar to that of a cellular phone. The exception being that cellular phones bounce calls from a cellular tower to an existing phone grid. Satellite phones use a series of satellites in orbit.

Making the call

The caller enters the number she wishes to dial and presses the send key. The phone proceeds to find the nearest orbiting satellite and sends the call information to it.

From space to Earth again (and again, maybe)

The satellite relays the call to the nearest ground receiver, known as a gateway. This gateway attempts to patch the call through. If a call to Australia originates in Europe, the gateway will not be able to patch the call through the existing phone network. The gateway will beam the call to the nearest satellite, which will continue passing the call along until it reaches one that can link the receiver. Depending on the location of the caller and receiver, this may happen a number of times.

From space to Earth, the final time

The call comes from the satellite and is received by receiver's network. The call's format has to be converted so that it may be received on a standard phone or cellular phone. Once the conversion is made and the connection established, the call is connected.

Source: ehow.com