Sat Phones?

[Solent sailer]

Does anyone have any experience with sat phones, I have a friend who is looking for a cheap option for hill walking/mountaineering where there is no standard mobile signal, should be all in Europe/mid latitudes so coverage at the poles is not a issue. I suspect the requirements will be very similar to many sailors so hopefully someone will be able to offer some advice.

thanks

 

[V1701]

Is it for emergency use only? If so, maybe a PLB could suit? Sat phones are still pretty expensive...

 

[Roberto]

Does anyone have any experience with sat phones, I have a friend who is looking for a cheap option for hill walking/mountaineering where there is no standard mobile signal, should be all in Europe/mid latitudes so coverage at the poles is not a issue. I suspect the requirements will be very similar to many sailors so hopefully someone will be able to offer some advice.

thanks

For mountain walking, a systems which does not rely upon geostationary satellites should perform better; when deep in a valley, the antenna may not see a geostationary satellite (like Inmarsat), whereas an overhead pass by an orbiting satellite might allow some communication time.
If it is just for land coverage, especially Europe coverage, then there are more available systems than for worldwide open ocean use.

 

[pyrojames]

I have an Iridium phone which I blew the data link on thanks to a wave but the phone/text still works. It would need a new PAYG account though.

 

[Monique]

Delorme In Reach is exactly what he needs

 

[st599]

Delorme In Reach is exactly what he needs

Iridium is 25 years old and the owners have been bankrupt a couple of times.

On a good day, you get 2.4 kbps.

 

[KellysEye]

>the antenna may not see a geostationary satellite (like Inmarsat)

Inmarsat: The constellation consists of 66 active satellites in orbit, and additional spare satellites to serve in case of failure Satellites are in low Earth orbit at a height of approximately 485 mi (781 km) and inclination of 86.4°. Orbital velocity of the satellites is approximately 17,000 mph (27,000 km/h)

Thus will work for hill walking and climbing.

 

[jdc]

>the antenna may not see a geostationary satellite (like Inmarsat)

Inmarsat: The constellation consists of 66 active satellites in orbit, and additional spare satellites to serve in case of failure Satellites are in low Earth orbit at a height of approximately 485 mi (781 km) and inclination of 86.4°. Orbital velocity of the satellites is approximately 17,000 mph (27,000 km/h)

Thus will work for hill walking and climbing.

You've just described Iridium, not Inmarsat. Iridium uses Low Earth Orbit (LEO), for which one needs multiple, but small and relatively cheap, SVs, whereas Inmarsat has vastly fewer geostationary ones. The Inmarsat SVs are huge and complex and very expensive!

It is true that Iridium was initially a project within Motorola, then spun-out as an independent concern and ran out of money a few times, but each time it was bailed out by US government contracts (some indirect) to keep it operational. So many people use it now that it is in my opinion likely to continue to be supported. Delorme's gadget uses the iridium system (hence the text message incompatibility with terrestrial cell-phones).

I also understand that ESA plan a similar system of LEO satellites for 'M2M' applications, although time way off still, and I imagine we could use this eventually.

http://en.wikipedia.org/wiki/Iridium_satellite_constellation

http://en.wikipedia.org/wiki/Inmarsat-4A_F4

 

[Roberto]

>the antenna may not see a geostationary satellite (like Inmarsat)



will work for hill walking and climbing.

I suggest you gather more information and study things a little better before writing sentences which are plain wrong.

Inmarsat satellites are on geostationary geosynchronous orbits, meaning they are kept on a fixed spot above the earth, their orbit has the same angular velocity than the earth.
In Inmarsat case, they are kept right above the equator: ever thought about why Inmarsat signal is not available around polar areas

If you are in a valley and the mountain range stands between yourself and the Inmarsat satellite you will not be able to get any signal, ever, until you change your position to a suitable spot.
On the other hand, while in the same position, one of the Iridium satellites will sooner or later pass over your area and allow to make your communication.

 

[[70521]]

Yellowbrick, a locator not a phone.

 

[prv]

I suggest you gather more information and study things a little better before writing sentences which are plain wrong.

Hasn't happened yet

Pete

 

[Monique]

We've lost the plot!!! OP wants it for trekking...

Delorme InReach is precisely what he needs.

 

[prv]

Delorme InReach is precisely what he needs.

Really? For all we know, he wants to have in-depth chats with his bed-bound mother-in-law. The InReach only sends text messages - how is that "precisely what he needs"?

The problem was framed as an alternative to a standard mobile when there's no coverage. As far as I can see, that means Iridium or Thuraya. I think Thuraya have some phones which can also take a SIM card and use the GSM network when available, which sounds like a good option since he's in a relatively civilised area and there's bound to be signal some of the time.

Pete

 

[Heckler]

Delorme In Reach is exactly what he needs

A big plus one.
S

 

[Heckler]

i

Really? For all we know, he wants to have in-depth chats with his bed-bound mother-in-law. The InReach only sends text messages - how is that "precisely what he needs"?

The problem was framed as an alternative to a standard mobile when there's no coverage. As far as I can see, that means Iridium or Thuraya. I think Thuraya have some phones which can also take a SIM card and use the GSM network when available, which sounds like a good option since he's in a relatively civilised area and there's bound to be signal some of the time.

Pete

The Delorme was originally developed for the sort of use that the OP is suggesting.
S

 

[prv]

i
The Delorme was originally developed for the sort of use that the OP is suggesting.

...for when you just need to send text messages. If that's what the OP's friend needs, then great. But he hasn't said that, he said he wanted an alternative to a mobile phone. If he wants to make voice calls then the InReach wasn't developed for that sort of use, was it?

Thuraya was developed as an alternative to GSM in areas of land (it's not global, the spot beams are aimed at specific regions) where there is no GSM signal. For mountaineering in Europe, that's exactly what the OP actually asked for, not what you're assuming his needs are.

Of course InReach is worth mentioning, in case he's happy with texts only, but until we know what he actually needs it's daft to claim that it's a perfect fit.

Pete

 

[afterpegassus]

Just to add to the comments, our local Mountain Rescue team uses Iridium because it provides the best mountain coverage. whilst I am not fully au fait with these things, our communications officer is, very; and he would not select a system that was less effective than others that might be available.