1. Satellite Network
- Geostationary Satellites: Some satellite phones communicate with geostationary satellites, which orbit the Earth at the same speed as the Earth's rotation, staying fixed over a specific area. These satellites are positioned at about 35,786 kilometers (22,236 miles) above the equator.
- Low Earth Orbit (LEO) Satellites: Other satellite phones, like those from Iridium, use a constellation of low Earth orbit satellites. These satellites orbit much closer to Earth, typically between 780 to 1,500 kilometers (485 to 930 miles), and move quickly across the sky.
2. Signal Transmission
- When you make a call on a satellite phone, your phone sends a signal to the satellite overhead.
- The satellite receives the signal and relays it either to another satellite in the network or directly to a ground station on Earth, depending on the satellite system in use.
- The ground station then routes the call to the public switched telephone network (PSTN) or the mobile network of the person you are calling.
3. Receiving Calls
- Incoming calls to a satellite phone work similarly. The signal is sent from the calling party to a ground station, then relayed up to a satellite, and finally transmitted down to the satellite phone.
4. Global Coverage
- One of the key advantages of satellite phones is their ability to provide coverage in remote and isolated areas, including oceans, mountains, and deserts. The global coverage depends on the satellite network. For example, Iridium offers near-global coverage, while other systems may have more limited ranges.
5. Latency and Call Quality
- The distance the signal travels can introduce latency, particularly with geostationary satellites. This can cause a slight delay in conversation. LEO satellites have lower latency due to their proximity to Earth.
- Call quality on satellite phones can vary depending on factors like weather conditions, the angle of the satellite, and the type of network used.
6. Power and Antenna
- Satellite phones often require more power than regular cell phones due to the long-distance signal transmission. They are usually bulkier and come with larger antennas, which need to be extended for the phone to connect effectively with the satellite.
7. Applications
- Satellite phones are commonly used in emergency situations, by remote workers (like scientists, explorers, and journalists), and in military operations where traditional communication networks are unavailable.
