What Is a Satellite Phone?

A satellite phone is a type of mobile phone. Like a cell phone, a satellite phone (also called a sat phone) is compact, lightweight and can be used for voice communication, text messaging and low-bandwidth Internet access (data). Some models of satellite phones also support Bluetooth and Wi-Fi, which allows the satellite phone to be used with a headset or connected to a laptop. However, there are some important differences between satellite phones and cell phones:

• Satellite phones communicate over a satellite-based network that resides in space whereas cell phones communicate via terrestrial (land-based) cell towers. Because sat phones transmit messages via satellites orbiting in space, satellite phones are designed to be used outdoors where the antenna can have a direct line-of-sight to the satellites in the sky. Cell phones can operate either indoors or outdoors, when in-range of cellular coverage.
• Most satellite phones have external antennas. Most cell phones have internal antennas. The antenna on a satellite phone needs to be deployed (extended) and have line-of-sight with the satellites in space, otherwise it will not be able to connect to the network and communicate.
• Some satellite phones offer a low bandwidth data connection, but the web browsing experience is nothing like what you’d experience using the high bandwidth connection offered by your smartphone. However, a satellite phone’s low bandwidth connection can be used for email, to send pictures, or download weather forecasts.
• Satellite terminals like Inmarsat, BGAN or Iridium Certus, offer higher-bandwidth data capabilities than satellite phones, and are best suited to higher-bandwidth data needs
• Most satellite phones have special international phone numbers, though some networks like Globalstar, provide US or Canadian phone numbers. Other networks like Iridium also offer a feature called two-stage dialing that allows your contacts to call a US-based phone number, that automatically connects to your (international) satellite phone number. This is because many traditional phone carriers charge as much as $10 to place a call to a satellite phone number, so two-stage dialing (ie. calling a US number) makes it much more affordable to place a call to a satellite phone. Some providers also offer the option of getting a dedicated US number in addition to your satellite phone number, which makes it less expensive for callers to reach you.

In summary satellite phones and cell phones offer similar voice and data communications services, in different ways.