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Slashback Privacy News

Slashback: Privacy, Spectrum, Location 198

Posted by timothy from the why-is-life-so-complicated dept.
Slashback tonight brings you yet another handful of updates and amplifications to previously posted stories, including some naysaying to Lessig's idea of the spectrum as commons, more free books from Baen, and the European answer to GPS. Read on for the details.

Sir, you just need to trust us. geekee writes "An article on CNN claims that the proposed passenger-screening system for air travelers is much more innocuous than previously claimed. Now it is claimed that the Transportation Security Administration "will not view credit records, traffic violations or other personal data", according to Admiral James Loy. He also claims records of travel will not be maintained. "Airline reservation agents would provide a traveler's name, address, phone number, date of birth, and travel plans to the TSA, which would then check that information against a variety of commercial databases and an FBI watch list.", according to TSA spokeperson Heather Rosenker."

Thinking of the children means more than hiding their eyes. Jim Tyre writes: "You pointed out that my censorware.net piece ["CIPA Before the Supreme Court"] provided a nifty link to where the official supreme court oral argument transcript would be when available online. It's now available."

What's good for the mercantilists ... wait, no doesn't have the same ring. Lawrence Lessig says that the current radio spectrum is vastly underutilized, and that new technology can extract much more use from it, creating a true radio commons. Zo writes to point out that many Salon readers disagree: "Radio waves, bandwidth, the spectrum. . .Don't we know *anything* for sure?

Sir, these books smell fine ... what's the catch? silentbozo writes "Avid Slashdotters will remember the Baen Free Library, which puts up free web versions of Baen titles for ANYONE to download and read without having to mess around with encryption and DRM. They went a step further with this experiment last fall with the release of David Weber's War of Honor which had a bunch of novels in html, rtf, doc, palmdoc, and othe formats on CD (bound into the hardcover), which you could copy and give away to anyone. Well, they're at it again. In May, they'll have another CD for those of you who didn't get War of Honor, bound into John Ringo's Hell's Faire.

I got hooked reading John Ringo's books after browsing through my copy of the War of Honor CD... and it's a great way of catching up on the previous books in the series. Hell's Faire looks really good - I personally am looking forward to finding out what happens to the O'Neals as they fight the Posleen on Earth, and to the crew of Bun-Bun... Eat anti-matter Posleen-boy!"

As secure as ... well, you pick. Anthanos writes "pGina [http://pgina.xpasystems.com], a modular authentication framework for Windows, has come a long way since it was last noted on /. nearly a year ago. Since then a full-fledged LDAP plugin, PAM plugin, and chaining have all become part of the feature set. The kicker is the recently released Slashdot plugin, which allows authentication of Windows clients with... yup you guessed it, Slashdot Accounts! XPA Systems has even begun offering services revolving around this GPL product. Seems this may be the solution for people looking to merge authentication of Windows clients with MacOSX, Solaris, and other *nix boxen."

Let's see a handheld that uses both, please ... Mattias Östergren writes "Well aware of the risks with dependency of GPS the European Space Agency (ESA) have developed their own satellite navigation system, EGNOS. EGNOS is more accurate than GPS and the signal also tell you how much it could be off.

The first reference station have just been installed on the roof of the Land Survey in Gävle, Sweden. There is a Swedish press release about it."
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Slashback: Privacy, Spectrum, Location More

Slashback: Privacy, Spectrum, Location

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  • Subscriber Preview (Score:5, Insightful)

    by Oculus Habent ( 562837 ) <oculus.habent@gma i l . c om> on Thursday March 20, 2003 @08:01PM (#5561191) Journal
    You know, previewing a story before it makes the page is really worthless on Slashback when you can't "Read More"
    • Only a fool would like MS-Vanilla over GNU/Butterscotch when there are so many reasons to eat butterscotch! It has enhanced flavor functionality as well as color functionality which distance itself so far from vanilla it's not funny. It's like comparing apples to oranges!

      -- iCEBaLM
  • About EGNOS ...
    Consisting of three geostationary satellites and a network of ground stations,
    If there's only three satellites, this must only be usable in Europe for now. Too bad -- 5cm accuracy would be sweet!

    (Actually, the existing setup is sweet, but 5cm would be much sweeter.)

    • Perhaps I just don't get it, but I am having trouble figuring out why anyone (outside of a small subset of the population) would need accuracy less than 50 feet or so. I suspect people that really need accuracy greater than this currently have the tools to achieve such accuracy. It's not like most people are letting their GPS device drive their vehicles or something. Plus for people that need better accuracy, there are means by which to get it, depending on how much you want to spend.

      But, as I said ea

      • Re:Looks like it's only usable in Europe for now . (Score:1, Funny)

        by Anonymous Coward
        Agreed. Clearly only terrorists would want anything with an accuracy better than 50 feet.
        • I hear they needed some accuracy when digging the Channel Tunnel, like for putting cables in place, and mapping their precise position ( so as to not be drilling, or whatever, through 'em years later )...
      • 2 bits are enough for anybody

      • It's not like most people are letting their GPS device drive their vehicles or something.

        No, but they let Microsoft Streets do it for them. And it's really annoying when your car symbol jumps from one street to a parallel one.

        Anyway, check out Geocaching [geocaching.com]. It's awesome, but an accurate GPS helps out a lot. You go around finding boxes of prizes with only a GPS coordinate and a couple of clues. It's great for excercise, and it's fun! You hear me, geeks? FUN EXCERCISE!
      • You've obviously never tried to find a geocache [geocaching.com] hidden in a field of boulders and rocks. Look for an hour or so and you get pretty mad.

      • Its easy to find uses for high accuracy. (Score:4, Insightful)

        by MyNameIsFred ( 543994 ) on Thursday March 20, 2003 @10:10PM (#5562069)
        While the subset of people that need high accuracy maybe small, that doesn't mean they're not economically significant. Just making surveying easier would be a hugh cost savings. Think of all the things that are surveyed. The lot your home sits on. The street in front of your house. In oil exploration, there's surveying of seimic sensors. The list goes on and on.
      • You've never been sailing, have you? In the fog ... Try it some time - you might suddenly get to appreciate the advantages of accuracy.

        Or you could try flying - in poor viz.

        But I agree, you just don't get it.

        • You've never been sailing, have you? In the fog ... Try it some time - you might suddenly get to appreciate the advantages of accuracy

          Tell me something...why do you think that the Coast Gaurd provides a free differential beacon? Could it be because you need something to make GPS more accurate than it is with Selective Availability? No...that could not be it. If you are sailing around, relying on nothing but a GPS reciever without differential correction to figure out where you are and where you are go

          • Tell me something...why do you think that the Coast Gaurd provides a free differential beacon?

            Er - they don't - I'm in Australia. The diferential service is pretty limited. Lots of coast, not many people.

            People got to places before GPS. Even before sextants. And compasses. And charts. But they died a lot doing it.

            I like GPS - its universal availablity and accuracy is a boon to all. Better accuracy would be good.

            I obviously fit into the group you don't believe in, the ones who would like better accuracy

    • I believe the claimed accuracy is 5 meters.

      Cheers!
    • Where does that 5cm number come from? It says 2m in the swedish text, and 5m in the english text..?

      (1m = 100cm, for those who find the decimalness of the metric system confusing)
    • RTFA. Sorry, but RTFABetter :). It states that this system is a precursor to Galileo, the worldwide system, but that this is in place above Sweden (and thus as you said available only in part of Europe).

      But yeah, it is sweet...and that's 2 meters (according to the swedish text as oposed to 5 meters in the english text...strange, that)PLUS an estimate of error in the reading (which could be 0.001 mm or 1 meter :)

    • Re:Looks like it's only usable in Europe for now . (Score:2, Informative)

      by Anonymous Coward
      Regarding availability; read the text! It says:

      EGNOS will achieve its aim by transmitting a signal containing information on the reliability and accuracy of the positioning signals sent out by GPS and GLONASS.

      So EGNOS works rather like WAAS. [selectzone.com] They provide corrections to the GPS signal. How do they obtain the corrections? A network of fixed ground stations with precisely known positions receives GPS, compares the GPS position with the actual position, and computes GPS corrections. Those corrections

    • More [pocketgps.co.uk] Information [thalesnavigation.com] about EGNOS and WAAS.

  • TSA background checks? (Score:5, Insightful)

    by teamhasnoi ( 554944 ) <teamhasnoi AT yahoo DOT com> on Thursday March 20, 2003 @08:12PM (#5561289) Journal
    What does my credit have to do with whether or not I should be in an airplane? Does shitty credit mean you're more likely to take a plane down with you?

    If so, how can anyone from Arkansas go anywhere?

    But seriously, all this background check BS is too much. Scan people and baggage. Lock the cockpit. Put an 'air cop' on board. What can you do? Not pay for movie headphones? (Credit be damnned, they make you pay in cash.)

    Background checks are unnessasary if the airport is secure in the first place.

    Ahh...I see. Its cheaper to run my SS/DL #s and invade my privacy than it is to change a door on an airplane. It must be, or airline would have done it a long time ago, because they care about people!^W airplanes.

    • Re: (Score:3, Insightful)

      by account_deleted ( 4530225 )
      Comment removed based on user account deletion

    • Re:TSA background checks? (Score:5, Interesting)

      by mmol_6453 ( 231450 ) <short.circuit@ma ... om minus painter> on Thursday March 20, 2003 @08:34PM (#5561420) Homepage Journal
      It has to do with statistics. Theoretically, the more information you have per data point, and the more datapoints you have, the more accurate your results are.

      The problem is, if you have too much information per datapoint, you start getting false positives.

      Think of it like your Bayesian spam filter(God, I LOVE Moz 1.3!)...the longer you train it (the more spam messages you feed it), the better it will be at recognizing the types of messages you give it.

      However, if you, say, start feeding it messages from your ex-spouse, it will start homing in on on other stuff. Possibly personal mail, or maybe legal notifications (depending on your situation. :) ).
      • It has to do with statistics.

        I think you hit the nail on the head. But here's the question. To what degree do we want our lives to be governed by actuarial accountants? How much can we trust them? Oh, math is math. But let's not let the word "statistics" get in the way of knowing that judgement calls are involved here.

        This is really the BIG QUESTION for us all. How do you discern right from wrong? Correct and incorrect? Probable from improbable?

        Think about Slashdot's moderation system for a mome

    • Re:TSA background checks? (Score:1, Interesting)

      by Anonymous Coward
      1) They said they were NOT doing credit checks.

      2) OBVIOUSLY this is more than just deciding if a single individual is "secure" for a single flight. They are attempting to track individuals that are on "lists". If a suspected terrorist gets on a plane, the FBI now has till that plane lands to decide if they want to pay him(her) a visit or not. If 20 of them all get on planes in one day to one location, well then...

    • Put an 'air cop' on board

      just as a side note, the term is actually 'air marshall.' which are some pretty highly trained, butt kickin, federal agents.

      • And how do you know that "air marshall" is still a marshall on this flight?

        You need two, that do not know each other. You allow all passengers to carry guns, so you do not have the good guys be known by bypassing security.

        So we will have to remove all security.

        So, let UAL and American go out of business, serves our goverment right.
    • Your credit actually seems to have a lot to do with a lot of things. Poor credit is correllated with a lot of things. For example, those with poor credit are more likely to have auto accidents and file claims. In fact, one insurance company I know had studies indicating that credit history was the most important predictor of future auto claims - even moreso that prior auto claims. Amazing.

      This makes a certain amount of sense. While many people do end up in credit trouble through no fault of their own

      • This makes a certain amount of sense. While many people do end up in credit trouble through no fault of their own (catastrophic medical bills, job loss, etc), very often people who end up with poor credit do so because they are unable to properly manage their fiances. Perhaps this indicates they are also irresponsible in other areas of their life.

        It's an awfully big conceptual leap to suggest that people who get into debt and don't pay their bills are also likely to blow up airplanes, now isn't it? Or
      • very often people who end up with poor credit do so because they are unable to properly manage their fiances.

        Yeah. I had a friend who had that problem. She dumped him in the end...

    • Re:TSA background checks? (Score:5, Insightful)

      by homer_ca ( 144738 ) on Thursday March 20, 2003 @09:41PM (#5561911)
      I think the theory goes that if someone has NO credit history (as opposed to a good or bad credit history), it's almost the same as having no past, and there's a higher chance that this person is using a false identity or an alias. Not that it would have helped with 9/11 because the hijackers travelled under their own names.

  • Missing tech format (Score:5, Funny)

    by RLiegh ( 247921 ) on Thursday March 20, 2003 @08:12PM (#5561290) Homepage Journal

    They went a step further with this experiment last fall with the release of David Weber's War of Honor which had a bunch of novels in html, rtf, doc, palmdoc, and other formats

    obviously not meant for technical documents; as I only see rtf, not rtfm format.

  • Any RF technician or audiophile can tell you that if you want to focus in on a specific frequency or range, you need good/better AC filters.

    For AM transmissions, theoretically a single, exact frequency can suffice. Assuming the transmitter is truly on the expected frequency, all you need is a very narrow bandpass filter.

    For FM transmissions, it's a little bit trickier. Simply put, the voltage being applied to your speakers (if one ignores all the fancy equilizer circuitry in a radio) is dependent on the
    • > For AM transmissions, theoretically a single, exact frequency can suffice. Assuming the transmitter is truly on the expected frequency, all you need is a very narrow bandpass filter.

      No. Mr. Fourier tells us that an AM signal consists of a range of frequencies. A single, exact frequency is just a pure sine wave, it carries no information. The bandwidth required for AM is just the bandwidth of the signal to be carried.

      For a simple example, try adding together two slightly different frequencies. You'l

    • Data rate is proportional to bandwidth. (Score:5, Informative)

      by Christopher Thomas ( 11717 ) on Thursday March 20, 2003 @08:55PM (#5561555)
      For AM transmissions, theoretically a single, exact frequency can suffice. Assuming the transmitter is truly on the expected frequency, all you need is a very narrow bandpass filter.

      If you try to send an AM signal across a 1 Hz band, you will get a 1 Hz bandwidth signal out at the other end. Not very useful if you were trying to play music. Definitely not useful if you were trying to transmit data.

      The number people are interest in is data rate. Data rate is bandwidth times the log to base 2 of the number of levels you can distinguish. Different encoding schemes (FM, wide-spectrum coding) express the relation differently, but the same limit applies.

      You can narrow the bandwidth, but as soon as you hit noise limits, your data rate starts going down too. *That's* the problem. Low-noise electronics doesn't help if the noise is from other users.

      The only way to avoid user clutter is to switch to something other than a broadcast system, which involves either large dishes or short-range transceivers and hubs connected to a _wired_ backbone.
    • > For AM transmissions, theoretically a single, exact frequency
      > can suffice. Assuming the transmitter is truly on the expected
      > frequency, all you need is a very narrow bandpass filter.

      Wrong. To send a 1KHz signal via AM you need 2KHz of bandwidth under theoretical best case conditions. You need bandwidth to even send Morse. If you are sending CW at a fast enough speed the bandwidth usage actually becomes non-trivial.

      If you can't be bothered to actually study some information theory before op
      • No, you need a 2KHz carrier frequency. That's not the same thing as bandwidth. Your signal can't change faster than half your carrier's frequency, since it becomes difficult to discern between your signal's affect on your line voltage and your carrier frequencies, since both your carrier and signal frequencies manifest as AC voltage on your antenna.

    • Re:Bandwidth IS underutilized! (Score:5, Funny)

      by nathanh ( 1214 ) on Thursday March 20, 2003 @10:07PM (#5562055) Homepage
      Any RF technician or audiophile can tell you that if you want to focus in on a specific frequency or range, you need good/better AC filters.

      Actually only the RF technician could tell you that. The audiophile would say that AM sounds warmer than FM but only if you're using oxygen-free radio waves. Then they'd start blithering on about how the crystals in their radio were hand-picked by virgins during the winter solstice.

    • This will ruin my karma, but... (Score:5, Informative)

      by john.r.strohm ( 586791 ) on Thursday March 20, 2003 @10:17PM (#5562105)
      The statement about AM is flat-out wrong.

      Do the fscking trig.

      Consider a sinewave modulating signal. Let c be the carrier frequency, and m be the modulating frequency. Recall that cos(u) varies between -1 and 1. We want the modulating control signal to vary between 0 and 1, so the modulator is 1/2(1+cos(m)).

      We use cos(u) because it simplifies the key trick in the derivation. OBVIOUSLY, it is just a phase shift to do it in sin(u).

      Then the fundamental equation of AM is

      f(t) = 1/2(1+cos(m))cos(c) (1)
      = (1/2 + 1/2cos(m))cos(c)
      = 1/2 cos(c) + 1/2 cos(m)cos(c) (2)

      The first term is the carrier wave. Observe that it carries half of the input power and NONE of the modulating signal.

      Recall from basic trig

      cos(u+v) = cos(u)cos(v) - sin(u)sin(v)
      and
      cos(u-v) = cos(u)cos(v) + sin(u)sin(v)

      Then
      cos(u+v) + cos(u-v) =
      (cos(u)cos(v) + cos(u)cos(v)) +
      (sin(u)sin(v) - sin(u)sin(v))
      which simplifies to
      cos(u+v) + cos(u-v) = 2 cos(u)cos(v)
      Or
      cos(u)cos(v) = 1/2(cos(u+v)+cos(u-v))

      That looks familiar. Recall (2)

      f(t) = 1/2 cos(c) + 1/2 cos(m)cos(c) (2)

      Substituting

      f(t) = 1/2 cos(c) + 1/2(1/2(cos(m+c)+cos(m-c)))
      = 1/2 cos(c) + 1/4 (cos(m+c) + cos(m-c))

      And there you have it. You have a carrier wave, and you have two sidebands, and the bandwidth of the whole thing is twice the modulating frequency.

      The next step is to observe that the Fourier theorem applies and is carried straight through, and so ANY modulating signal will generate two sidebands, one above and one below the carrier wave, each preserving the harmonic content of the modulating signal, but with one reversed in frequencies.

      Your explanation of FM is just as bad. I'm not going to do the derivation, because it is MUCH messier, involving very ugly Bessel functions, and I don't have my textbook handy.

      You can reduce the bandwidth of an FM signal, but you lose fidelity.

      You can reduce the bandwidth of an AM signal by band-limiting the input audio information, which is routinely done in voice communications gear: the full audio spectrum goes up to NOMINALLY 20 kHz, but the useful speech formants are pretty much all found between 300 Hz and 3 kHz.

      You can suppress the AM carrier wave, and you can suppress one of the sidebands. This is also routinely done, in single sideband communications. This involves loss of redundancy and loss of easy tuning, which in turn makes careful tuning much more important: any mistuning comes out as distortion.

    • I'm sure Lessig is a very capable lawyer, but I wonder what he would say if I asked him who Nyquist and Fourier are. Could he explain the theories for which they are well known?

  • TSA Data Gathering (Score:4, Funny)

    by dacap ( 177314 ) on Thursday March 20, 2003 @08:28PM (#5561379) Homepage
    Awww. Not so threatening, eh? I was hoping the TSA would go for the whole data collection tamale. Think what happens when the US Gov tries to build a newly designed, big, complex system -- bidding by defense contractors is long, drawn-out, and then it is challenged and redone; the contractor that finally wins takes forever to complete it, if ever; if the contractor actually manages to build something, it's completely unusable; in disgust, the govt throws it away and starts the cycle again with more bidding. Just ask the FAA, LOL!

    Therefore urge TSA not to compromise their standards, fellow /.ers. That way we'll have no data collection, ever.

  • Galileo Information (Score:5, Informative)

    by Aaron M. Renn ( 539 ) <arenn@urbanophile.com> on Thursday March 20, 2003 @08:44PM (#5561490) Homepage
    As I've long argued, there's no real justification for Galileo. It's about the EU (esp. France) wanting to avoid looking weak next to the US. It is about industrial policy and euro-prestige. There is no reason not to rely on the US GPS system, which already has billions in upgrades planned, including fully separate civilian only signals. The US also has local jamming capabilities that does not require the military to globally degrade signals.

    At any rate, there's a lot of good Galileo information on the web. Here are some links:



    These links are from a file I have of info on Galileo. Hopefully no link rot.

    • Re:Galileo Information (Score:5, Interesting)

      by ergo98 ( 9391 ) on Thursday March 20, 2003 @09:06PM (#5561638) Homepage Journal
      There is no reason not to rely on the US GPS system...

      Really? [slashdot.org] I would beg to differ. I say this under the context that the US taxpayer bought and paid for the GPS, so they have no duty to guarantee any level of service, however some of the arguments against a European GPS system seems to be along the lines of the kid who's taking his ball home and gets angry when he sees that they got their own ball.

      Political sidenote: I love how the administration has set up a whole slew of ridiculous propaganda techniques to give the illusion of a dangerous enemy to enrage the public into a president supporting, pollster responding public. Want to invade someone? Up your dubious "threat level" as if you are responding to some overt immediate threat from the deadly enemy. Want to pretend that your enemy is more powerful than they really are? Talk about disrupting GPS, lest they guide their 1960s era Soviet T55s by it... Eurasia...europa...who knows anymore. I am making no comment about the righteousness of this war, but I hope that people can see through these shallow manipulations.
      • I agree that Europe would do well to have it's own system for the reasons you mention, but they BETTER be able to degrade it at will, otherwise attackers will be able to build Galileo-driven targetting systems and cruise missiles will be able to hit European targets using their own satellites.

        As far as anyone else using them against us is concerned, we'll just jam the Galileo frequencies in our AO. Americans would be advised not to buy Galileo handsets because we may have to set up jammers for all non-GPS
    • Yeah...I mean, imagine a GPS signal which is 4 times as accurate, and gives you an error margin to boot. And it's a system which doesn't have a built in inacuracy for the public, and won't be changed in accuracy whenever someone wants to have a war, thus making it safe for missioncritical applications (like airtravel, all year round surveying etc).

      Nah, an obviously inferior system, made by people who are jealous of another counrty. It couldn't have anything to do with a part of the world wanting a better s
    • You know what, trusting the Bush administration after the hilarious episodes of:

      - Fake uranium orders from Niger
      - Student's thesis from 12 years ago presented as convincing evidence
      - Meaningless wiretappings presented as evidence ... conjures up images of the Goatse guy asking for more, much more up the ass.

  • TSA vs. FOIA (Score:4, Insightful)

    by NOLAChief ( 646613 ) on Thursday March 20, 2003 @08:47PM (#5561504)
    IIRC, government-held info that's supposed to be purged from someone's record has a nasty tendency to stick around (whether by accident or by design). I wonder how hard the TSA and the DHS will make it to submit a FOIA request to verify that this information *is* being purged after each flight.

  • I agree with many Salon responses to rx spectrum (Score:4, Interesting)

    by LM741N ( 258038 ) on Thursday March 20, 2003 @08:49PM (#5561514)
    As an RF/Microwave Engineer, I deal with the problems with RF interference daily. A recent article I saw online lauded the participation of ham radio operators in disaster situations including the World Trade Center relief operation.
    Imagine thousands of devices and gadgets emitting radiation on random frequencies, and you can see the problems that might arise in critical communication situations. The background noise level at HF frequencies is already very bad due to consumer devices. I would hate to see it get any worse.
    • You misunderstand the arguement. The frequencies are far from random, and the equipment is designed to expect frequency hoping, amongst other things. That is the most basic step toward a better utilized spectrum, one that has been used since WWII.

      -R
      • Yes, and if you want to redesign and replace every radio on the planet, using technology that is significantly more expensive, or doesn't even exist yet, be my guest. But you have to replace my TV with the $20,000 frequency hopping spread spectrum one.

        Also frequency hopping spread spectrum was designed to stop jamming since it's hard to broadcast across a very wide spectrum at high power. But give one of these transmitters to everyone in a metropolitan area and watch the mayhem insue. All cell networks

  • EGNOS != GPS (Score:4, Informative)

    by ByTor-2112 ( 313205 ) on Thursday March 20, 2003 @08:50PM (#5561526)
    EGNOS is the European answer to WAAS, folks, not GPS.

  • EGNOS isn't GPS (Score:5, Informative)

    by fruity_pebbles ( 568822 ) on Thursday March 20, 2003 @08:51PM (#5561527)
    EGNOS is the EU's equivalent of the FAA's WAAS. EGNOS and WAAS are systems that supplement GPS by providing corrections (thus giving higher accuracy) and integrity monitoring, so a GPS receiver will be informed if a GPS satellite is outputting bad data.

    EGNOS is only available in Europe at the moment because it's only being transmitted from one geostationary satellite that's sitting over Europe. WAAS is currently being transmitted from two geostationary satellites over the Americas.

    Neither system is what I'd call new - they've been in a sort of beta test phase for years, and there are already consumer receivers on the market that support EGNOS/WAAS.

    • Mod this guy up, he actually posted the details that I was too irritated to bother with.

      Do ANY of you slashdotters actually know anything about the technology you harp about? Or maybe check the URL's...
    • Also of note, there is a european answer to GPS called Galileo, but it's really not moving very fast, and won't necessarily be any more accurate for civilian use than GPS is for civilian use.
    • Geosynchronous satellites have to orbit around the equator...

  • Not so bad on Lessing. (Score:3, Informative)

    by Erris ( 531066 ) on Thursday March 20, 2003 @09:13PM (#5561679) Homepage Journal
    Most of the letters, but one or two bizare ones supported Lessings basic thesis. Tom Rouch has this offensive comment for Salon:

    It would be much more productive if Reed and other "architects of the Internet" spend time finding solutions to EM pollution caused by switching power supplies and digital systems, rather than proposing ways to make problems worse in areas they clearly don't understand.

    This comment follows a rant which ironically ignores most modern radio breaktrhoughs: packet routing and frequency hopping on low power devices to create a network with far greater bandwith than a single transmitter per frequency set up that's current. Instead, he focus on ancient details of antenae size and signal propagation. It's amazing that someone could ignore the demonstrated reality of Alohanet and 802.11B meshworks and then call others ignorant.

    Then again a simple search pulls up stuff about Tom Rauch. Is this guy a profesional slammer or what?

    Well, fine, he knows his tubes and amps, IF the first person linked to above is not correct in assesing him as a whore. You have to be suspicious of people who rant so.

    All of the other letters on that page supported Lessing's conclusion that the broadcast spectrum is poorly allocated and mostly empty. There was that one bizare and false analogy to a pinhole cameras with no pinhole. I've never seen a pinhole radio, it must be intersting.

    • RTFA! (Score:2, Insightful)

      by MrTilney ( 188646 )
      Please read the original article before you attack the character of people who put their real names in the reply. The pinhole camera thing came right out of the article, and highlighted the gross lack of technical knowledge of the author. College freshmen in physics and engineering know that radio waves interfere. It's the basis of quantum mechanics.

      The reply of Rauch was completely accurate. I'd like to see you send any signifcant power at modern radio or TV frequencies without a giant antenna. Mesh

      • Re:RTFA! (Score:3, Insightful)

        by dlakelan ( 43245 )
        So what you're saying is that the reason we can't move forward with radio technology is that people in the back woods will have no way to watch "Must Miss TV" (TM)?

        The sheer failure to grasp the concept is so amazing to me. Even the geeks don't get it.

        1) Open up some portion of the spectrum to unlicensed transmitters that are limited only by reasonable health concerns and basic mode of operations limits(ie. a few watts effective radiated power in the UHF band with "minimal required output power" type regu
    • This comment follows a rant which ironically ignores most modern radio breaktrhoughs: packet routing and frequency hopping on low power devices to create a network with far greater bandwith than a single transmitter per frequency set up that's current.

      Mesh routing schemes break down in highly populated areas - you end up with too many messages needing to be routed by any given node, and the fraction of node bandwidth used for that node's messages dropping like a rock.

      Relation is a fun exercise in calcula
      • Mesh routing schemes break down in highly populated areas - you end up with too many messages needing to be routed by any given node, and the fraction of node bandwidth used for that node's messages dropping like a rock.

        That's debatable but think about what you are saying. If only a fraction of the currently restricted bandwith were so well utilized! As it is, you hear silence. Which is preferable? The possibility of a clog or enforced silence and frustration? What is it that you stand for?

        • think about what you are saying. If only a fraction of the currently restricted bandwith were so well utilized! As it is, you hear silence. Which is preferable? The possibility of a clog or enforced silence and frustration?

          Clogging is a certainty without imposed limits; people are greedy that way. Removing band restrictions just guarantees that *all* parts of the spectrum are clogged.

          Band restriction is a quality of service issue - if you want to be able to use your cell phone, or to put up an antenna an
          • you say: Limit wireless to short range, and put hubs everywhere. Problem solved (for urban areas; rural areas are an entirely different problem with different constraints).

            So you would have no free long range high power spectrum at all? That's realy short sighted (pun intended), and I'm happy to think that the FCC chairman disagrees with you. The cost of all that badwith you want would be considerably less if more spectrum was given over to 802.11B type freedom. The equipment is cheap enough that people

            • Limit wireless to short range, and put hubs everywhere. Problem solved (for urban areas; rural areas are an entirely different problem with different constraints).

              So you would have no free long range high power spectrum at all?

              There would be a few bands open for hobbyists, just like there are now. Want to build a 1 kW transmitter? Go ahead - just get your ham license first. Decide you're not going to play nicely in the community? Your license gets revoked.

              Without management, anything longer than short
              • There would be a few bands open for hobbyists, just like there are now. Want to build a 1 kW transmitter? Go ahead - just get your ham license first. Decide you're not going to play nicely in the community? Your license gets revoked. Without management, anything longer than short-range will cause too many people to step on each others' toes.

                Nonsense! No electronic device, licensed or unlicensed my interfere with federally allocated spectrum. You don't need to yank a license to shut someone down any more

                • No electronic device, licensed or unlicensed my interfere with federally allocated spectrum. You don't need to yank a license to shut someone down any more than I need to build my own kW system (the orignial 802.11 alocation was supposed to be 100W!). If it were legal to use the spectrum, reputable builders would come to the rescue.

                  You miss my point. I'll state it more clearly:

                  If you have a reason to transmit signals long distances, you can do so cheaply by filling out the appropriate forms and following

  • Radio Spectrum Underutilized (Score:5, Informative)

    by digitaltraveller ( 167469 ) on Thursday March 20, 2003 @09:24PM (#5561779) Homepage
    Currently there are three ways to partition the available spectrum:

    FDMA (Frequency Division Multiple Access): The standard technique of TX/RX on different frequencies (or colors if you read the analogy on Slashdot a few days ago). Ho-hum, it's the first thing I would have tried too. Our predominate and most wasteful technique.


    CDMA (Code Division Multiple Access): A set of spread-spectrum techniques that use a sort of RF kung-fu to manipulate previously considered undesirable properties of radio waves to advantage. On the coolness factor the engineers that designed these technologies should be in the nonexistant Engineering Hall of Fame. The scuttlebut is that some of this technology was invented by Qualcomm as early as WWII but was highly classified until recently, so Qualcomm still holds most of the patents to this today.


    TDMA (Time division multiple access): This involves standard unix-like time splicing, except using radio signals. GSM works like this by partitioning groups of eight consecutive time slots to form a TDMA frame with a duration of 4.615 ms. Each transmitter (cell-phone) in the area gets one burst period (a slot) of duration 15/26 ms (approx. 0.577 ms) to use the channel. This is an immensely powerful technique, and one that is infinitely scalable. It's only limitation is the speed of our electronics, which can and should maintain it's exponential speed curve.
    This is why the spectrum is underutilized.
    • Where the hell do you get your info?

      Most modern radios (I mean those in cell phones/WiLan) use a combination of these techniques. Furthermore you have a serious lack of understanding of the technologies you mentioned.

      First, CDMA is considered on the forefront of spread spectrum technologies today, TDMA is old-hat. Second, TDMA is not infinitely scalable. If you have shorter time slices, you increase the bandwidth. There is no free lunch, you have to use bandwidth to send data. You can sometimes incre

      • Re:Please, do some research once in a while (Score:4, Interesting)

        by WolfWithoutAClause ( 162946 ) on Thursday March 20, 2003 @10:41PM (#5562231) Homepage
        TDMA is old-hat.

        Yes, but not necessarily worse for that. WiFi uses it, as does ethernet for that matter.

        Second, TDMA is not infinitely scalable.

        True, and false ;-)

        True in the sense that sending more bits between two nodes increases the frequency band used, and eventually the band interferes with surrounding bands.

        However, if power control, node routing and directional antennas are used the network throughput scales up proportional with the number of users; and TDMA supports this.

    • Re:Radio Spectrum Underutilized (Score:5, Interesting)

      by Christopher Thomas ( 11717 ) on Thursday March 20, 2003 @10:19PM (#5562119)
      [TDMA] is an immensely powerful technique, and one that is infinitely scalable. It's only limitation is the speed of our electronics, which can and should maintain it's exponential speed curve.
      This is why the spectrum is underutilized.

      You do realize that as sampling rate goes up, spectrum use (bandwidth) goes up, right?

      Any given region of spectrum can only carry so much data, any way you slice it. Power, noise/clutter, and bandwidth combined determine (and limit) data rate.
    • There's also have a sort of space division multiplexing- i.e. using directional antennas. That concept is used on TV aerials among others.
    • Currently there are three ways to partition the available spectrum.

      CDMA's and CDMA hybrids are being used in favor of the others. Everyone's doing CDMA now.

      Checkout http://www.astalavista.com/mobile/wct.shtml [astalavista.com] for a longer list.

  • not Lessig : it was David Reed / David Weinberger (Score:3, Informative)

    by DrSkwid ( 118965 ) on Thursday March 20, 2003 @09:32PM (#5561843) Journal
    it's :
    The myth of interference
    Internet architect David Reed explains how bad science created the broadcast industry.

    - - - - - - - - - - - -
    By David Weinberger

  • EGNOS enhances GPS, doesn't replace it (Score:5, Informative)

    by RevLimiter ( 179253 ) on Thursday March 20, 2003 @09:47PM (#5561939)
    EGNOS is the European version of WAAS, a system that enhances GPS accuracy by providing differential corrections (like DGPS, only from a satellite instead of a ground-based transmitter).

    It's currently in testing, and is expected to be turned on for real soon.

    See http://gpsinformation.net/waasgps.htm

  • Aldenata OGL D20 RPG on the disc & on the web (Score:4, Interesting)

    by Robotech_Master ( 14247 ) on Thursday March 20, 2003 @09:50PM (#5561948) Homepage Journal
    One noteworthy thing about the CD-ROM that's not mentioned in that orientation is that it will include a (partly-)OGL D20 RPG based on the Aldenata books, which you can currently find hosted in rich text form at Alldenata.net [alldenata.net] under the link marked "rules." (I'm not entirely sure why the spelling of the aliens changed between the first few books ("Alldenata") and the most recent one ("Aldenata"); nobody on the John Ringo Baen Bar group seems to want to talk about it.)

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