A satellite telephone is a telephone that can be mobile or fixed in one spot. Although it works similar to land-based cellular phone, a satellite telephone relies on satellites in the atmosphere to relay communications from one person to another. It is most commonly used in remote places, where the land-based telephone lines and cellular towers are not present, such as in undeveloped countries or on an ocean-going boat. It can also be helpful if other forms of communications are unavailable due to a natural disaster, such as an earthquake, hurricane, tidal wave, or other devastating event.
If a satellite telephone is transportable, it looks much like a modern cellular phone or smartphone. These phones are most often used when someone travels to an area where a typical cellular phone signal is hard to find. For example, someone traveling in remote areas of Central or South America may find a satellite telephone helpful. In the alternative, a satellite telephone that is in a fixed spot, such as on a boat or in a rural village, is much bulkier.
Some satellite telephone services provide full coverage of all areas of the globe, while others provide regional coverage. Most services are divided between their use of geosynchronous satellites and low Earth orbit satellites. In addition, some countries, such as North Korea, do not allow residents or visitors to possess satellite telephones. These countries may regulate or even block satellite telephones from transmitting signals.
Geosynchronous satellites are placed at a certain height in the atmosphere. These satellites travel at the same speed as the rotation of the Earth. The result is that the satellites do not appear to move. Consequently, few satellites are need for global coverage. On a downside, there can be a noticeable signal delay and shaky voice communications using these satellites, making communications unpleasant.
Low Earth orbit satellites are placed much lower in the atmosphere than geosynchronous satellites. Since they are lower to the ground, more satellites are necessary to give full coverage. On the upside, the signal has fewer delays and communications are often clearer.
The satellite telephones can range from moderately priced to quite expensive. There is usually a cost per each minute of use as well. In addition, there are some plans in which the user can pay for minutes before using them, saving some money. Some satellite telephones offer Internet connections in addition to the ability to provide vocal communications. Although most people will not use a satellite telephone instead of a land-based phone or a cellular phone, it may prove useful when least expected, making the cost irrelevant.