A satellite phone primer

What a satellite phone actually is

A satellite phone — or satphone — is a handheld or transportable device that uses orbiting satellites instead of cellular towers to carry voice calls, SMS and data. Where there is no terrestrial network, where mountains block line-of-sight to the tower, or where you need a connection that does not depend on local infrastructure, a satphone reaches up to the sky and finds a satellite.

What it can and can’t do

Most modern satellite handsets give you:

• Voice calls to any normal phone number worldwide
• Text messages in and out (sometimes via email)
• Position reporting and SOS via integrated GPS
• Low-bandwidth data — email, weather, position — typically over a USB or Bluetooth tether

What they don’t do well: streaming, social media, web browsing, video calls. The narrow-band devices are voice-first. If you need real broadband in the field, you want a BGAN or Certus terminal — that’s a different category of kit.

The four networks at a glance

Every commercial satellite service belongs to one of four operators. The choice between them is, more than anything else, a choice about where you’ll be using the phone.

Iridium

The only network with verified global coverage, including the poles. Uses a constellation of 66 low-earth-orbit satellites, cross-linked in space, so a call you make in Antarctica is handed satellite-to-satellite back to a ground station. Excellent for travel, expedition, polar, maritime and aviation use.

Inmarsat

Geostationary satellites — fixed positions in the sky above the equator — covering everywhere except the poles. Big spot-beams give stable, higher-bandwidth links, so Inmarsat is strong on maritime safety (FleetBroadband, FleetSafety), field broadband (BGAN) and aviation. The IsatPhone 2 handset is famously rugged with industry-leading battery life.

Thuraya

Two geostationary satellites covering Europe, Africa, the Middle East, Asia and Australia. Strong on pocketable handsets — the Thuraya XT-PRO is the thinnest satphone made — and the SatSleeve adapter that turns a smartphone into a satellite phone. Built-in GSM fallback is genuinely useful for travellers.

Globalstar

A 24-satellite low-earth-orbit constellation with a “bent-pipe” architecture — your call goes up, the satellite relays it straight back to the nearest ground station, the call is connected. The result is exceptional voice clarity in covered regions (Americas, Europe, Australia, parts of Africa and Asia), and the well-known SPOT trackers for personal safety.

Coverage matters more than features

The most common mistake is picking a phone on features when the deciding factor is coverage. Iridium will work anywhere; the others won’t. If you’ll only operate inside a known coverage area, you can pay less and get more useful features for the money.

We’re independent of the operators, so we will gladly tell you that Iridium is overkill if your job is a fishing trip off Scotland — or that you absolutely need it if you’re heading to Svalbard.

Choosing airtime

Airtime is sold by:

• Prepaid units (vouchers) — top up minutes that expire after a fixed period. Best for occasional users.
• Monthly plans — a recurring bundle of voice, SMS and data. Best for regular users; cheaper per minute.
• Pooled / business plans — for fleets where allowances are shared across multiple SIMs.
• Pay-as-you-go SIMs — small monthly fee, high per-minute cost. Best for “in case of emergency” use.

Most customers pick a phone first, then a plan. Talk to us before you decide — picking the wrong plan is the single most expensive mistake a satphone customer makes.

Renting versus buying

If you only need a satphone for a single trip, rental almost always beats buying. We rent IsatPhone 2, Iridium 9555, Iridium 9575 Extreme, Iridium GO! and BGAN terminals by the week. See our rental options.

What to do next

1. Read “What’s for you” if you want a 5-minute opinionated recommendation by use case.
2. Use the comparison tool to filter phones by coverage, weight, battery life and price.
3. Call us on 0800 747 6747 — we don’t bite, and we’d rather spend ten minutes on the phone than ship you the wrong phone.

That’s the primer. Read on, or ask a human.