Satellite Phone

Satellite Phone

Satellite phones work in places that mobile phones have no chance of receiving a signal

Satellite Phone 

Satellite Phones

At the top end of scale for two-way flexible communication is the satellite phone.  Once the preserve of journalists or explorers, it is actually becoming closer to a reality for use in the mountains.  Having a satellite phone may seem a little excessive, but the topic is included for completeness, and it’s not actually as mad as it sounds.

Satellite phones get their signal from satellites in Earth orbit in space (either orbiting or geo-stationary), whereas mobile phones get their signal from land based masts.  Hills & mountains block terrestrial mobile phone radio signals, so in theory at least, a satellite phone will have a signal when a normal mobile phone will not, provided its antenna is in clear view (no roof or other obstructions) of the satellite. There are some differences between satellite systems. Mobile phones don’t need to be in direct line of sight to a mobile phone mast/cell site, as the mobile signal radio waves can be reflected around corners & through walls etc.  The same is not true for satellite communication. As the satellites are thousands of miles away the power of the signal is weak, and as such an unobstructed line of sight from phone to satellite is required.  It is for this reason that satellite phones have big antennae when compared to normal mobiles.

Satellite phone to contact emergency services in mountains

There are four satellite phone providers: Globalstar, Iridium, Inmarsat and Thuraya.  

From a UK perspective, Globalstar & Iridium will work best. Inmarsat and Thuraya will also work in the UK, but the satellite position is low to the horizon, meaning that mountains will probably block the direct "sight" of the satellites, unless you're on top of a hill, or in a valley running north to south for Inmarsat, or north west to south east for Thuraya. 

Here's Chas modelling a Globalstar satellite phone in an area of the Lake District that had no mobile signal, but did have immediate coverage on Globalstar's network.

The 66-satellite Iridium constellation is truly global, including the poles, but handsets are expensive. Globalstar has the best voice quality but does not cover much of Africa, India, Indochina & Indonesia, though that's hardly a limitation for UK usage. The Globalstar GSP1700 handset weighs only 200g, equivalent to a few gulps of water.

If you're walking in the back of beyond of the Scottish Highlands, or other location with little or no mobile signal, should you consider carrying a satellite phone? The argument increases if you're leading a group.

Contacting the emergency services from a satellite phone in the UK is not straightforward, as you can’t dial 999. Globalstar do run a 112 service, based in France, and one would hope that a call would be appropriately routed to the UK. However, you'd be advised to have local police non-emergency landline number, or alternatively phone and pass details to your EPOC, who would then have to contact 999 on your behalf.  (Here's a link to police non emergency land line numbers.)

Unlike PLBs and satellite messenger products, satellite handsets are not waterproof and are relatively fragile. 

Handsets and Costs


Features and costs


Handset approx £300 – weight 200g

Monthly fee €12 – pay as you go option available

No text message sending (can receive up-to 35 characters)



Handsets from £900+

Monthly fee min $40, or

Pay as you go option approx £300 for 6 months validity

Text message send & receive capability


Not included in this summary as not really suitable for UK mountain area use



Not included in this summary as not really suitable for UK mountain area use


The above table is indicitive, and does not show inclusive calls etc.  Non-inclusive calls are considerable more expensive that mobile phones.

Global Telesat Communications (GTC) are a UK based company which specialises in Satellite Communication. Kind assistance with this page from GTC.