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The Telecom Digest for October 13, 2011
Volume 30 : Issue 259 : "text" Format
====== 30 years of TELECOM Digest -- Founded August 21, 1981 ======
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Date: Wed, 12 Oct 2011 08:13:53 -0400
From: Monty Solomon <monty@roscom.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: iPhone 4S Meta-Review: It's the Same, But Like Better
Message-ID: <p062408cbcabaec5b5884@[10.0.1.9]>
iPhone 4S Meta-Review: It's the Same, But Like Better
By Casey Chan
Gizmodo
Oct 11, 2011
The first reviews are out for the iPhone 4S and they're a lot like we
expected, which is to say, exactly what we expected: the same phone
on the outside but much better on the inside. It's faster, has a much
better camera and packs a golden bullet with Siri.
...
http://gizmodo.com/iphone-4s-review/
Date: Wed, 12 Oct 2011 08:13:53 -0400
From: Monty Solomon <monty@roscom.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: New iPhone Conceals Sheer Magic
Message-ID: <p062408c8cabae8de8753@[10.0.1.9]>
New iPhone Conceals Sheer Magic
By DAVID POGUE
October 11, 2011
What's in a name?
A lot, apparently. Apple's new iPhone is called the iPhone 4S. But
what people really wanted was the iPhone 5.
The rumors online had predicted the second coming - or, rather, the
fifth coming. It would be wedge-shaped! It would be completely
transparent! It would clean your basement, pick you up at the airport
and eliminate unsightly blemishes!
Instead, what showed up was a new iPhone that looks just like the
last one: black or white, glass front and back, silver metal band
around the sides. And on paper, at least, the new phone does only
four new things.
...
http://www.nytimes.com/2011/10/12/technology/personaltech/iphone-4s-conceals-sheer-magic-pogue.html
***** Moderator's Note *****
Thank you, David.
Bill Horne
Moderator
Date: Wed, 12 Oct 2011 23:05:44 +1100
From: David Clayton <dcstarbox-usenet@yahoo.com.au>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Lightsquared being called to account
Message-ID: <pan.2011.10.12.12.05.39.215799@yahoo.com.au>
On Tue, 11 Oct 2011 19:11:33 -0400, Gary wrote:
> ***** Moderator's Note *****
>>
>> I don't know what other military devices or aircraft use GPS, but I
>> think it's reasonable to assume that their designers took account of
>> the possibility of jamming. It's a military use, after all.
Just like the TCP/IP protocol takes care of the possibility of misuse, DOS
attacks etc., after all, that was created for the military to be able to
work even in the event of a nuclear attack, wasn't it?
>
> I'm fairly certain that most of our military uses GPS, from grunts on
> the ground to ships to probably anything in the air (other than shells,
> at least for now :-). After all, GPS was developed to serve our
> military's needs.
>
> What most people don't know (it's not a secret), is that there is a
> second GPS band used only by the military. Using two bands allows the
> receivers to compensate for variations in the ionosphere allowing for a
> more accurate measurement of propagation delay from the the satellites.
> The end result is military receivers are much more accurate than
> civilian receivers (just how much is, of course, a secret). The second
> channel is encrypted.
>
> Because of the second channel as well as minimal concerns about the cost
> to build a good product, I'm quite certain that it is much harder to jam
> a military GPS receiver than a $100 civilian receiver.
...........
I still don't believe that it's a good idea to require the manufacture of
transmitters using frequencies near the ones the GPS devices use and have
them available for commercial use. I still remember how easy it was to
"hack" CB radios to use channels way off the official ones, and that was
back in the 1970's!
The basics of any radio system - including GPS - is the requirement of a
minimum S/N ratio to work reliably, having powerful transmitters in the
vicinity of devices that have to receive tiny signals from a number of
transmitters a long LONG way away to function (no matter how "directional"
any antenna system may be) compromises that basic requirement. How long
until the bad guys obtain and hack one of these things to directly jam
military GPS devices? It will probably be a lot easier to obtain a
commercial device than build one yourself.
--
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.
Date: Wed, 12 Oct 2011 09:50:06 -0400
From: Telecom Digest Moderator <redacted@invalid.telecom.csail.mit.edu>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Lightsquared being called to account
Message-ID: <20111012135006.GA8451@telecom.csail.mit.edu>
On Wed, Oct 12, 2011 at 11:05:44PM +1100, David Clayton wrote:
> On Tue, 11 Oct 2011 19:11:33 -0400, Gary wrote:
>
> > ***** Moderator's Note *****
> >>
> >> I don't know what other military devices or aircraft use GPS, but I
> >> think it's reasonable to assume that their designers took account of
> >> the possibility of jamming. It's a military use, after all.
>
> Just like the TCP/IP protocol takes care of the possibility of misuse, DOS
> attacks etc., after all, that was created for the military to be able to
> work even in the event of a nuclear attack, wasn't it?
No, it wasn't. That bit of revisionist history has been around for
years, but it's wrong.
TCP/IP was designed to make a reliable network out of unreliable
links, i.e., to leverage the voice-band data circuits of the
1970's. To accomplish that goal, the design team employed the concept
of "store and forward", where each hop in a chain of links could
retain packets and retransmit them again and again until the next hop
confirmed that it had received a valid copy.
That is why there is NO minimum transit time specification in the IP
protocol, and that is why VoIP and other near-real-time applications
have so many problems with latency: VoIP is only possible now
because data links are so reliable now compared to the 1970's.
Military networks are all about transit time and hardening assets
wherever possible, and TCP/IP doesn't fit in that mold.
The "store and forward" concept was applied to email messages, as
well: every MTA (Mail Transfer Application) is capable of holding an
email until the destination is available, sometimes for days. Although
anti-spam measures have limited the capability, it's still available
for use.
If you want proof that TCP/IP wasn't intended to be a military
network, ask yourself why DOS attacks, spam, etc. are possible at
all. The answer is that the designers of the Arpanet were academics,
NOT military men! Their world view did not include the possibility
that someone would break the rules for commercial gain, let alone for
sabotage, and no competent military design team would leave such
things out of a plan.
Bill
--
Bill Horne
Moderator
Date: Wed, 12 Oct 2011 08:30:04 -0400
From: "Gary" <bogus-email@hotmail.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Lightsquared being called to account
Message-ID: <j7418h$2r0$1@dont-email.me>
**** Moderator's Note *****
>
> Although Loran was still in use during the time I was working on these
> sorts of issues at Verizon, it was, IIRC, not accurate enough for the
> timing we required. I don't remember specifics, but (again, IIRC) I
> think there was too much ambiguity caused by multi-path propagation
> for us to adopt Loran. Ah, well: sic transit technology.
Actually, with the right receiver, these issues could be mitigated. We used
a specially designed Loran-C timing receiver that detected and handled
multi-path signals and other noise like lightning (a "little" DSP goes a
long way). We tested several sites by manually switching to Loran-C for
timing and then monitoring the difference between Loran-C and GPS. Over the
course of many days and weeks the difference stayed well within the specs
needed to operate the base station.
Loran-C was an elegant solution for our system as it provided not only
redundancy in timing [but also] redundancy by using very different
radio signals.
I agree that technology moves on, however I think that Loran-C was shut down
before its time. It offered a very valuable complement to GPS. Running at
a very different frequency and being a terrestrial based service, it was
subject to a very different set of issues that GPS. It was very unlikely
that both services could be knocked out at the same time due to weather,
jamming, or interference. My understanding is that Loran-C cost about $15
million a year to operate. Yes, our government needs to carefully manage
our money, however Loran-C looked to me to be well worth the relatively
small cost to the country.
I'll stop crying in my beer now.
-Gary
***** Moderator's Note *****
First, a clarification: the Loran-A system was retired in 1980, and
that's the medium-wave version I mentioned in another note. Gary is
writing about Loran-C, and long-wave version that operates at roughly
100 KHz. It's still in use in some parts of the world, but was retired
in the U.S. and Canada in 2010.
As to cost: I'm not so sure of the $15 Million figure.
According to Wikipedia:
On 26 February 2009, the U.S. Office of Management and Budget
released the first blueprint for the Financial Year 2010
budget. This document identified the LORAN-C system as
"outdated", and supported its termination at an estimated savings
of $36 million in 2010 and $190 million over five years.
Rest at
http://en.wikipedia.org/wiki/LORAN
Bill Horne
Moderator
Date: Wed, 12 Oct 2011 19:51:47 -0400
From: "Gary" <bogus-email@hotmail.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Lightsquared being called to account
Message-ID: <j7596o$qf2$1@dont-email.me>
***** Moderator's Note *****
>
> As to cost: I'm not so sure of the $15 Million figure.
>
> According to Wikipedia:
>
> On 26 February 2009, the U.S. Office of Management and Budget
> released the first blueprint for the Financial Year 2010
> budget. This document identified the LORAN-C system as
> "outdated", and supported its termination at an estimated savings
> of $36 million in 2010 and $190 million over five years.
I didn't remember the exact figure; that's why I said "about" $15 million.
In government speak, I was very close. :-)
Even at $36 million a year, I think Loran-C was a bargain. I'd be amazed
if GPS doesn't cost us taxpayers way more. And don't get me started
comparing Loran-C to other things our government spends our money on...
If it isn't clear, I don't think Loran-C was outdated. I believe it was a
great complement to GPS that provided a redundant timing and location
service. But the OMB didn't ask me.
-Gary
Date: Wed, 12 Oct 2011 10:48:40 -0400
From: Bill Horne <bill@horneQRM.net>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: AF gen: GPS, LightSquared "Can't coexist"
Message-ID: <4E95A8C8.1090206@horne.net>
My thanks to Bill Carton for sending in this material from the DODBUZZ website:
The boss of Air Force Space Command, Gen. William Shelton, does not
want to get any more mixed up in the political imbroglio between
the FCC, Republicans, Democrats and the broadband startup
LightSquared. His job, he told reporters Tuesday, is to protect the
Global Positioning System, and to that end, he reaffirmed at the
Air Force Association's trade show that GPS and LightSquared's
proposed network "cannot coexist".
Simple as that.
He said as much during a question and answer session after a speech
to the convention and then again to reporters in a press briefing
afterwards. In fact, Shelton even picked up a pen and drew a
diagram to illustrate how LightSquared's network effectively jams
the signal that military GPS receivers need to get their precise
timing and location data. Shelton pointed to his diagram and said
that even under LightSquared's alternate proposal for its network,
which would move its signal farther away from GPS, it would still
squelch the ... frequencies that precise receivers use.
Read more:
http://www.dodbuzz.com/2011/09/20/af-gen-gps-lightsquared-cant-coexist/
And yes, it IS as simple as that. That's the difference between an
Air Force Academy graduate and a venture capitalist: one of them can
count, and the other thinks that the laws of physics are negotiable.
Bill Horne
(Remove QRM from my email address to write to me directly)
"There's a party down at Cal's
Vinnie Charles is out of jail again
His Ex's will be there
His daughter 'Nita has bought him an easy chair"
- John Gorka
Date: Wed, 12 Oct 2011 12:16:29 -0400
From: "Charles Jackson" <clj@jacksons.net>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Lightsquared being called to account
Message-ID: <002401cc88fa$4ce8d2b0$e6ba7810$@jacksons.net>
An earlier message stated:
For the benefit of those not familiar with Loran, it was a
medium-wave technology which operated in the 160 meter band, just
above the frequencies used by AM broadcasting in the U.S. to this
day, i.e.,, 1.8 to 2 MHz. Propagation delays, atmospheric
phenomena, and lightning all affected the performance of Loran,
and those factors, in addition to the extraordinary power levels
required for the transmitters, were some of the reasons for it
being retired in favor of Inmarsat and GPS.
I think the "current" version of Loran transmits at about 100 kHz. See the
Wikipedia article or
http://www.navcen.uscg.gov/?pageName=loranReference
.
Chuck
***** Moderator's Note *****
Chuck, thanks for the information.
Bill Horne
Moderator
Date: Wed, 12 Oct 2011 15:41:16 -0600
From: fatkinson.remove-this@and-this-too.mishmash.com
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Lightsquared being called to account
Message-ID: <9c6e031b9eca7de303d9a9789fe16451.squirrel@webmail.mishmash.com>
> An earlier message stated:
>
> For the benefit of those not familiar with Loran, it was a
> medium-wave technology which operated in the 160 meter band, just
> above the frequencies used by AM broadcasting in the U.S. to this
> day, i.e.,, 1.8 to 2 MHz. Propagation delays, atmospheric
> phenomena, and lightning all affected the performance of Loran,
> and those factors, in addition to the extraordinary power levels
> required for the transmitters, were some of the reasons for it
> being retired in favor of Inmarsat and GPS.
>
> I think the "current" version of Loran transmits at about 100 kHz. See
> the
> Wikipedia article or
>
> http://www.navcen.uscg.gov/?pageName=loranReference
> .
>
> Chuck
>
> ***** Moderator's Note *****
>
> Chuck, thanks for the information.
>
> Bill Horne
> Moderator
>
>
It was my understanding that Loran has been discontinued.
Was that information wrong?
Fred
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