How a Satellite Phone Works - Answers Today


Guide to how a Satellite Phone Works 

A satellite phone connects to orbiting satellites rather than ground-based cell towers. It works by establishing a radio link with a satellite network that has multiple satellites circling the earth and transmitting signals.

When making a call on a sat phone, the signal travels from the phone to the nearest satellite in range. Most satellite phone networks have stable connections to several satellites orbiting the earth at any given time. 

The satellite then transmits the signal back down to the nearest ground station, which connects into land-based phone networks.

So the call path goes:

1. Cellular signal from satellite phone →

2. Captured by orbiting communications satellite →

3. Signal beamed to ground-based station →

4. Routing over landline/cellular networks →

5. To the receiver phone

In order for the satellite phone to lock onto satellite signals for transmitting calls, the phone needs to have clear access to the open sky. 

Connections can get sporadic or disconnect when inside buildings, under heavy tree cover or in deep valleys that have obstacles overhead.

Most modern satphones utilize multiple cellular bands to also connect to terrestrial tower signals when available. 

The phone automatically switches between satellite and cell tower connections depending on the strength and availability of each network in that location.

Let's dive deeper into the world of satellite phones

Beyond the basics:

While the core principle of satellite phone communication remains the same (linking to orbiting satellites instead of towers), there's more to the story:

  • Satellite networks: Two major players dominate the scene - Iridium and Inmarsat. Each utilizes different satellite constellations:

    • Iridium: Employs a network of low-earth orbit (LEO) satellites, offering truly global coverage (including poles) and faster connection times. However, signal handovers between satellites can be more frequent.
    • Inmarsat: Leverages geostationary (GEO) satellites, resulting in wider coverage across most landmasses and oceans (excluding poles). These satellites maintain fixed positions, providing a more stable connection but slightly slower call setup and data speeds.
  • Phone technology: Unlike regular phones, satellite phones require specialized hardware:

    • Antennas: These are crucial for transmitting and receiving signals to/from satellites and are often larger and more robust than in regular phones.
    • Protocols: Satellite phones use specific protocols like SATCOM (Satellite Communications) for communication, differing from GSM or CDMA used in cell phones.
  • Additional features: Modern satellite phones go beyond voice calls:

    • Data services: While generally slower than terrestrial networks, some plans offer data access for email, text messages, and basic web browsing.
    • GPS: Many phones have built-in GPS functionality for location tracking and emergency assistance.
    • SOS buttons: Dedicated buttons directly connect you to search and rescue services in case of emergencies.

Top satellite phone services

  1. Iridium: Known for its global coverage, fast connections, and emergency SOS features. Popular models include the Iridium 9575 Extreme and Iridium GO! for data connectivity.
  2. Inmarsat: Offers a wider range of pricing options and data speeds, suitable for diverse needs. Popular models include the IsatPhone 2 for affordability and BGAN M2M for data-intensive applications.

Other options in 2024

  • Globalstar: Offers budget-friendly plans but with limited coverage compared to Iridium and Inmarsat.
  • Thuraya: Primarily focuses on coverage in specific regions like Europe, Africa, and the Middle East.

$ 875.00
Iridium GO! Portable Satellite Smartphone Access Device

Things to consider when choosing

  • Coverage: Where will you be using the phone? Do you need truly global coverage (Iridium) or mainly land-based (Inmarsat)?
  • Data needs: Do you require basic data access or heavier internet usage (Inmarsat offers wider options)?
  • Budget: Satellite phone services and devices can be expensive. Compare plans and features carefully.
  • Additional features: Consider if features like GPS and SOS buttons are crucial for your needs.
  • Where to buy without a hassle from the top service providers is provided below! 

Remember, while satellite phones offer invaluable connectivity in remote areas, they are not a replacement for regular cell phones in everyday use. 

Weigh your needs and budget carefully before investing in this specialized communication technology. 

If you go off-grid these devices can be a life-saver!

References- learn more:

* Iridium Communications -

* Satellite Phone Services in 2024