Satellite Phone
Thursday, August 7th, 2008
A satellite phone or satphone is a mobile phone that sends and receives calls using satellites rather than landlines or cellular broadcasting towers. A satellite phone only requires a clear line of sight to the sky. It is completely independent of the local telecommunication infrastructure available.
Line of sight usually means the satellite phone (or antenna) must be located outside to send or receive a call. In certain cases they will work inside buildings (with large clear glass windows), provided the windows are facing the right direction with a clear and unobstructed view of the sky
The advantage of a satellite phone is that it can complete calls from anywhere. A satellite phone can operate in the middle of the Sahara desert, at the top of Mount Everest, or from a clearing deep within a South African jungle.
A disadvantage of a satellite phone is a noticeable delay in conversations. The signal must first travel to the satellite, then to an earthbound gateway before being routed to the receiver. The receiver’s response will follow the same path in reverse, taking equally long to reach the caller. Satellite minutes are also more expensive than cellular minutes.
Iridium satellite phones are walkie talkie size, Inmarsat phones are laptop size -weighing approximately 2.4 kgs for the Mini-M, to 4.5 kgs for the World Communicator.
Satellite telephones rely on technology that was initially developed for military purposes. Another aspect of satellite phones is that local agencies like police, firefighters, medical emergency teams, and similar services can now be in touch with critical information on a real time basis. The next generation of satellites will have to be launched to keep the service going.
References:
Introduction & Advantages: http://www.wisegeek.com/what-is-a-satellite-phone.htm
Disadvantages: http://www.wisegeek.com/what-is-a-satellite-phone.htm
http://www.wrights.co.nz/communications/iridium_rent.htm
Conclusion: http://ezinearticles.com/?Satellite-Phones-And-The-Future&id=784115