A satellite phone can be used anywhere such as on mountains, deserts, and airplanes and even in the middle of a sea, whereas a cellular phone can be used only where cellular service is available. Cellular phone service hardly reaches the high seas, mountains, deserts and other remote areas.

Cellular phones use cell towers for communication. These cell towers or cell sites receive and send signals to mobile devices within their range, whereas Satellite phones use low earth orbiting satellites for communication. The quality of voice in satellite phones is excellent when a direct line of sight is present between the phone and satellite. However, the quality might degrade substantially in areas with tall buildings.

Unlike cellular phones, satellite phones can be rented for few days or months depending on the satellite service provider. One of the best satellite phone rentals is provided by Iridium, which covers most of the remote places on earth through its vast network of low orbit satellites.