satellite phone [Telecom]

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What is a good newsgroup for asking about satellite phone
capabilities?

***** Moderator's Note *****

I assume from your timestamp and headers that you're in Europe, so
I'll defer to others since I don't know the regulatory environment
there. This may seem like a moot point, given the international nature
of geostationary satellites, but individual countries are still able
to regulate radio transmitters that operate within their borders,
which includes satellite phones.

Bill Horne
Temporary Moderator

(Please put [Telecom] at the end of your subject line,
or I may never see your post! Thanks!)

We have a new address for email submissions: telecomdigestmoderator
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Re: satellite phone [Telecom]
On Tue, 8 Jul 2008 18:46:30 -0400 (EDT), geek@mybits.nospam.thanks
wrote:

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Besides   http://en.wikipedia.org/wiki/Satphone which is very
informative what other webpages or online resources exist to inform me
about satphone basics and capabilities? Do they have an IMEI in the
main phone and a SIM card as do cellphones? Is it possible for an
Iridium or Inmarsat phone to be located on the Earth's surface by
triangulation, so say you're in a boat and you want to know where the
boat is, can a satphone locate you? What service providers exist for
satphone and is there a list of these and their prices anywhere?


Re: satellite phone [Telecom]
On Wed, 9 Jul 2008 06:46:35 -0400 (EDT), geek@mybits.nospam.thanks
wrote:

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Can anyone lend a clue with these questions?


Re: satellite phone [Telecom]
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sat phones are _proprietary_ architectures.  they work only with the
satellite system they are designed to be used on.  there are currently
only two such sat. systems   InmarSAT and  Iridium.   features and
capabilities differ depending on which of those two services you are
talking about.  Little need for the complexities of an IMEI and SIM
in the phone -- they _all_  either talk to one vendor, or they talk to
"nobody".   Google for INMARSAT and IRIDIUM.  you should find the provider
pages.  Given what the sat provider offers, you should be able to fgure
out _WHAT_ the various 'resellers' can provide.`


Re: satellite phone [Telecom]
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There appear actually to be dozens of different satphone systems in
Europe and the Mideast.... Inmarsat and Iridium are the only two ones
with worldwide coverage but there are a bunch of other services that cover
only limited areas.  They may well also use proprietary data formats.
--scott


--
"C'est un Nagra.  C'est suisse, et tres, tres precis."


Re: satellite phone [Telecom]
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This might be a good time to learn more about Thuraya, who provide GSM
satellite service in Europe, Africa, Asia, and Australia.  They have
roaming agreements with carriers all over the world, although none in
the U.S.

The phones are different from normal GSM phones, but if you put a SIM
from a carrier with a roaming agreement into a Thuraya phone, it'll
work.

R's,
John


Re: satellite phone [Telecom]
wrote:

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Let's suppose I'm a terrorist, which I'm not. I get a Thuraya phone,
which operates with two satellites. You can't triangulate with two
satellites. How is the NSA going to track down the dangerous terrorist
using just two satellites when the phone is connected to only one of
them? Does it have to look at transmissions from the Earth's surface,
which are directed at a particular satellite? How on earth is American
intelligence going to track down these people?

Even with Iridium or Inmarsat which have lots of satellites, how is it
possible to track down / triangulate on a satphone when it is in
contact with only one satellite and the other satellites don't care
about that satphone? You would need to track down the tranmission on
the Earth's surface surely?

I can't help thinking we are being sold a dud with the story of
tracking down satphones and it isn't actually possible to catch al
Qaeda using these methods. It is far more likely that US intel have
paid an al Qaeda operative tens of thousands of dollars for betraying
his own people and offered him immunity. It's not possible to do
technically is it?

Cellphones no problem because those are always on the radar for a
thickly forested cellphone tower structure and you can tell from
strengths of tranmissions to various towers where the individual
cellphone is located.

I am speaking as an amateur and not a radio freak so correct me if I'm
wrong.


Re: satellite phone [Telecom]
It was a dark and stormy night when geek@mybits.nospam.thanks wrote:

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Don't count on that.  You know the positions of the satellites, and
that's to locate a point on a known surface (of the earth).  It seems to
me that would reduce the possible location to two points, which will
probably be far enough apart so that the wrong point could be ignored.
Come to think of it, if those satellites are moving with respect to the
earth, each satellite will observe the call from continually changing
points on a line.  I'd bet you only need one satellite to do it (and it
doesn't have to be Thuraya's).

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In any case, what makes you think that those two satellites are the only
two receivers that can pick up the signal?  Whenever you're running a
radio transmitter (which any wireless phone is) you're running a
veritable beacon.  Don't forget the Chechen insurgent whose satellite
phone apparently was used to target a Russian missle.  I'm sure that the
Americans have other satellites that can pick up the signal, probably
the Russians do, maybe the Chinese.  And then there's aircraft.  And
fixed stations with very large antennas.  And, closer, trucks.

And, of course, they can use that technology to listen to anybody, not
just "terrorists".

Dave


Re: satellite phone [Telecom]
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Why do you assume that the 'phone' satellites are the _only_ birds that can
listen to the sat-phone transmission?

Do you suppose that spy satellites *can* listen on those frequencies,
and that they "just may" have directional facilities?

You'd be surprised at how much 'location' information a single bird can
pull from a ground-based signal -- carrier 'doppler shift' analysis can
give a surprisingly precise fix, putting the transmitter on a particular
line perpendicular to the satellite track, just for one example.


Re: satellite phone [Telecom]
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With ground-based systems.  Or with military satellite systems that
are designed for listening in and locating signal sources intended for
others.

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Yes.  

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A lot of it can be done technically, but in the whole, it's generally
a lot cheaper and more effective to pay someone off.  Unfortunately our
Federal friends who answer phones with numbers instead of names have
forgotten this and have basically abandoned boring human intelligence
programs in favor of flashy signal intelligence.  This has come to bite
all of us.

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That doesn't tell you all that much... it lets you know what cell the
user is in, but triangulating the user within the cell still requires
additional hardware.
--scott
--
"C'est un Nagra.  C'est suisse, et tres, tres precis."


Re: satellite phone [Telecom]
On Fri, 18 Jul 2008 01:20:50 -0400 (EDT), kludge@panix.com (Scott
Dorsey) wrote:

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  It is not difficult, but designing building and deploying the
equipment won't be cheap.  Though if it gets mass produced and
deployed widely that would drop the costs well into the commercially
viable range.

  A big part of making a working sat-phone, or a plain old TDMA CDMA
GSM EDGE cellphone is tied to precise timing and time-keeping.
Multiple users have to share a single radio channel, to get the system
carrying capacities needed.  Each phone set has a very accurate
internal clock, and even as it is idling without a call in progress it
is slaved to a Strata 1 clock through the phone system.

  When a call is set up the phone is assigned a specific channel set
and timeslot for the call, and it has to transmit the voice translated
into data packets in millisecond long bursts several times a second.
And it receives the other end of the conversation audio using the same
packet-burst method.

  If you have two or three receivers (either satellite or ground
based) and measure the time delay of how long the signal took getting
from the transmitter to each receiver, you can triangulate the
transmitter location rather accurately.

  Even from one or two receiving sources you can narrow it down to two
or three possible locations - then the satellite receiver moves along
in it's normal orbit and the logical triangulation cuts the probable
locations down to one - the others are either in the middle of an
ocean, or moving way too fast to be a stationary person - they can
tell the relative speeds from Doppler shift.

  That's the exact opposite of GPS - the satellites transmit the
calibrated pings, and the receiver times and triangulates from the
satellite signals.  And a consumer grade GPS can tell you location and
elevation down to within feet.

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  Cost is the reason it hasn't happened widely already.  Unless and
until the government required that a cellphone be trackable, the
cellular companies would not invest in the equipment - they won't
incur a cost that isn't recoverable.

  Even after phones were required to have GPS chips and triangulation
systems were to have been installed (and all the old analog phones
without it were to be retired) we still get people lost in the woods
that call in - and the 911 PSAP can't tell exactly where they are from
those signals.   The information gets lost along the chain.

  Just had one of those last week in northern California, they told
the lost hiker to shut their phone off overnight to conserve the
batteries, hunker down for the night, and call the 911 PSAP back in
the morning.  (And they probably had to send technicians out to the
cell sites to extract the info.)

   Once they had a latitude and longitude to work with, sending out a
helicopter to pick them up was easy.

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  Yes, but that additional hardware isn't all that difficult to build
and deploy at each cell site ahead of time, though it is going to cost
a bit.

  They use the same method, they already know exactly when the signal
was transmitted from the call setup auto-negotiations.  They just need
to know the time delay for the signal to arrive at each receiver, and
it is helpful to know which quadrant antenna it was strongest on, and
they can draw a 'distance from receiver' arc on the map.

  Two arcs intersecting is a probability location, and if the phone is
in a very rural location they might only see one tower well an and a
second very faintly if at all.  They might have to remotely command
the phone to go to full power and look for other receiver hits.

  But three or four distance arcs intersecting on the map is a fairly
certain location fix.  And accuracy of +/- 100 feet is plenty close
enough - someone on the ground can sniff out more accuracy than that
if needed.

     --<< Bruce >>--


Re: satellite phone [Telecom]
 [ snip ]

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I'd betcha that in a hefty number of those situation the problem
is that the "911 surcharge" [a] applied to cell phone customers,
which was supposedly designated specifically to upgrade the PSAPs
to "enhanced 911", simply went to general gov't coffers.

[a] in quotes because while called a surcharge, it's really
most sincerely a ... _tax_... by another name.

Speaking of which, whatever happened to the proposal, post 9/11,
to design briefcase sized pseudo cell sites? The idea was
that if you suspected people wre trapped in rubble (and
had a cellphone), you could walk over there with the
briefcase and figure out were to dig.

Similarly, if someone was in a forest or other large area,
you could drive by on the roads, or be up in a helicopter,
and find them.



--
_____________________________________________________
Knowledge may be power, but communications is the key
             dannyb@panix.com
[to foil spammers, my address has been double rot-13 encoded]


Re: satellite phone [Telecom]
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I believe that other DoD agencies have revealed that the NSA can track
satphones.  These other agencies behaved in a manner that I would
characterize as incredibly stupid.  This has pissed the NSA off.  Oh
well, maybe we'll do better in the next war.
--scott
--
"C'est un Nagra.  C'est suisse, et tres, tres precis."


Re: satellite phone [Telecom]
geek@mybits.nospam.thanks writes:


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Well, the easy was is to listen to the GPS position the phone is
reporting back to the control point. During the Great Invasion of Iraq
by the Embedded Masses of Press, and ps, also the US Army & USMC; the
military confiscated the reporters' Thuraya phones, because allegedly the
current position of the incoming attack wave was secret.

--
A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433


Re: satellite phone [Telecom]
geek@mybits.nospam.thanks wrote:
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One of the greatest intelligence community mistakes was bragging how
terrorist could be tacked using the satellite phones. Consequently
they have stopped using any form of electronic communications. So yes,
you can be tracked with a sat phone.

Google for satellite phone.


Re: satellite phone [Telecom]
On Sat, 12 Jul 2008 21:56:57 -0400, DTC wrote:

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"Tracked"!, have a look at how many "terrorists" have been blown up in
the last few years by honing in on phone handsets' signals.

If you have a major technological power after you, don't use comms
technology or you might as well paint a target big enough to be seen from
space on your back.

--
Regards, David.

David Clayton
Melbourne, Victoria, Australia.

Knowledge is a measure of how many answers you have, intelligence is a
measure of how many questions you have.


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