Satellite Phone Service A satellite phone is similar to a telephone device, which sends signals to satellite that are then directed to PSTN (Public Switched Telephone Network) or other communication networks. In other words, it is a mobile phone that uses orbiting satellites as a medium of communication rather than using terrestrial cell towers. The satellite mobile coverage can cover entire earth or a specific region. The mobile equipment used in this setup is also known as a Sat phone. These phones used to have retractable antennas in older days but the latest phones are similar to mobiles phones and have internal antennas. Three different types of satellite systems are used in satellite communication. They differ according to the type of orbit they follow around the earth and can be classified as follows: Geo-stationary satellites: These types of satellites are placed 22,000 miles above the equator. These satellites complete one revolution around the earth in 24 hours and stay at fixed location above the earth’s surface. A single geo-stationary satellite covers 40 percent of earth’s area, whereas a series of satellites are required to cover the entire surface of the earth. Low-earth-orbit satellites: These types of satellites are placed a few hundred miles above the earth at a stationary altitude. They complete one revolution around the earth within 90 minutes. The communication system is arranged in a way that at least one satellite is in line of sight at any given time and at any specific point on the earth. Satellite orbiting in Elliptical pattern: These types of satellites move fast around the earth when they are placed at a lower altitude, but move slowly when placed at a higher altitude. Limitations of Satellite Phones:Satellite phones work well only if there is a clear line of vision between the sky and its antenna. They don’t function properly if there is frequent obstruction between the phone device and the satellite. Mountains, trees, buildings and other obstructions can act as a barrier in their connectivity. Therefore these devices do not function properly when used indoors. Area of Use: Satellite phones are used extensively in rescue and relief operations. Explorers and adventurers rely on these phones to communicate in areas where landlines or cellular mobile phone services are not available. Reporters also heavily depend on sat phones to post breaking news from remote mountainous regions such as those in Afghanistan and others parts of the world. Also, people traveling on a Caribbean cruise can contact their families using these phones.