* High speed satellite systems usually feature a specifically configured hardware terminal at each end of a connection. A telephone jack located at the remote site on the remote terminal is connected to a customer-provided telephone or FAX machine. A remote terminal is connected to the satellite Internet service via a standard Ethernet connection.
* On the landline end the host terminal is connected via Ethernet to the customers LAN switch or hub. The host terminal features a standard telephone jack which connects to the standard telephone line. Telephone calls made to the remote site telephone number will ring through as though the remote site telephone were in the same room as the host terminal although there is a three-quarter of a second of delay.
* Calls made via the remote side will be local if local to the telephone line, or are placed through the selected long distance carrier.
* Even though it does seem to be an almost mystical way of communication there are a few natural laws that satellite telephones can’t break:
* Satellite telephones need a clear line-of-sight view of the satellite.
* For an Iridium Satellite telephone, for example, this means that the phone’s antenna must be outside with a relatively unobstructed view of most of the sky. Iridium phones use a non-directional antenna. This means you don’t have to point it in any direction.
* Inmarsat telephones use geostationary satellites so the antenna does need to point directly at the satellite with an unobstructed view. The antenna will also need to be outside, but it’s fairly easy to set up. The Inmarsat system makes use or four satellites which are positioned above the equator.
* If you need to operate the phones inside a building a long antenna cable extension is fitted. This allows the telephone handset to be used inside. If you will be inside a vehicle or for maritime use, the Inmarsat is fitted with an optional automatic antenna, which points itself towards the satellite.
*Limited Bandwidth
* Satellite telephones work by sharing the limited resources of a satellite amongst users in many different countries. Satellite engineers have developed astounding systems that allow narrow-band carriers to be used to carry our voice signals.
* The technology isn’t capable of delivering high bandwidth data. Even though Internet access is possible, connections can be very slow.
* Higher bandwidth options require a large antenna version of the Inmarsat system - Inmarsat M4. or a Satellite Broadband option which uses DVB-RCS technology.
Satellite telephones are invaluable for many fields of work, for example news reporting, working with wildlife or in field medicine and can be a life-saver in an emergency or disaster situation. Most of us won't need to make use of a satellite telephone in the normal course of events but if you do choose to invest in one at least you will be able to say you know how satellite telephones work. I am quite sure it will impress your friends!
