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FCC Approves 802.11b Phased Array

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  • High effect (Score:2, Interesting)

    With a long range like that I guess your brain will be pretty fried if you sit close to the AP, no?
    • Re:High effect (Score:1, Offtopic)

      by tigress (48157)
      I dunno. Is its effect higher than the two watts normally found in a standard cellphone?
      • Re:High effect (Score:3, Informative)

        by interiot (50685)
        Two watts? Are you on crack? Try 600 - 125 milliwatts [mcw.edu].
        • Re:High effect (Score:3, Interesting)

          by tigress (48157)
          I stand corrected. I based my comment on third party information, from someone who was supposedly wireless certified. Still 600mW is a lot more than what an AP is allowed to output (100mW) around here, and you don't usually press an AP against your ear, now do you? =)
        • Re:High effect (Score:5, Informative)

          by tigress (48157) <rot13.fcnzgenc03@8in.net> on Tuesday December 17, 2002 @06:31AM (#4906073)
          Actually, on second thought...

          Peak power output corresponds to 2 Watts or 2000 milliwatts (mW) which averages to 250 mW of continuous power. An analogue phone (AMPS system) has peak power limited to 600mW.

          Source [arpansa.gov.au]
          • AMPS (Score:4, Interesting)

            by wowbagger (69688) on Tuesday December 17, 2002 @08:47AM (#4906378) Homepage Journal
            An AMPS phone may be limited to 600 mW in the systems in Australia, but the actual limit on a Power Class 1 Phone is 5 watts. That is one of the reasons that replacing the AMPS system with (CDMA|TDMA) systems in the US has been very slow - a Class 1 phone can contact a base station many tens of miles away, which is IMPORTANT in much of the US - when you are in western Kansas, Nebraska, Wyoming, Montana, Utah ... you get the point.

            That was part of why the old phones where so large - a 5 watt 100% duty cycle power amp isn't tiny. (the other reason was that since AMPS requires the phone to transmit and receive at the same time, the phone had to have an RF duplexer in it - not a small item, even at 800MHz. TDMA phones don't transmit and receive at the same time, hence they don't need the duplexer).

            That's one of the reasons I tell people to look for the old phones at garage sales - get the phone and you have a dandy 911 phone - you WILL get a connection!
    • Re:High effect (Score:4, Informative)

      by AndrewMcG (193365) on Tuesday December 17, 2002 @05:47AM (#4905949)
      Actually, that's why it needed certification. It won't, it has very little different output to your laptop card. It works by actively steering antenna beams at associated users. Very cool for ISPs and big campuses.
      • Actually, the FCC doesn't limit raw power, it limits power per solid angle steradian [techtarget.com] (actually, it's usually max power/square area at a certain distance -- effectively the same, but no confusion over near-field effects of the antenna). Just like using a magnifying glass to concentrate sunlight, it can be just as dangerous to concentrate RF power - and the FCC knows this.

        Still, the increased bandwidth due to multiple beams will be very helpful in overcrowded environments.
  • by Skrap (105397) on Tuesday December 17, 2002 @05:45AM (#4905946) Homepage

    This will be especially relevant for Bandwidth co-ops.


    The biggest obstacle to creating a co-op is having enough potential subscribers to convince the telcos that it will be worth their while to run the dry pairs the "last mile" from the DSL POPs to the houses. I am guessing that this technology will begin to allow metropolitan bandwidth co-ops to have an effective solution outside of the telco's control. Please, oh please, let broadband not suck forever.

    • I've been awaiting the resurrection of Ricochet in Orange County, CA, but with a four-mile radius I could (using company money, of course--I doubt this new AP will be cheap) set one up at home and at the corporate office and have the effect I try to achieve using (past tense) Ricochet and (present tense) T-Mobile HotSpots. That effect is to change my environment to either a nearby park, pub or (what's a another p-word? It's early) other place while I work. Within a couple miles of both home and office I have parks, lakes, pubs, restaurants. . .just not the beach (maybe I still will need Ricochet!).
    • You know, there were several reasons that 10base2 only allowed 30some hosts per segment, but a not insignificant one was that collisions don't increase linearly as you add hosts.

      Despite what some believe, 802.11 is basically a single pipe, shared with everyone. This simply isn't the solution you're looking for, even if it is the only one available.

      Reminds me too much of idiots who use USB for cd burners and the like. Then they wonder why the mouse cursor is unresponsive.

      I'm not a troll... I do sympathize. I want to figure out how to get broadband to everyone too. But this isn't it.
      • I don't think you've made a case for why the idea is inherently flawed. Certainly what we have now would not scale. But the cable co's seemed to have made a shared medium work. Scalability problems can be addressed by policy makers freeing up spectrum for more nonoverlapping channels.
        • Neither of us have made a good case. Do not forget, that the cable company's "shared network" is actually any number of shared segments, and often hybrid-fiber (rarely pure fiber though?). Wires (and especially fibers) can carry quite a bit more bandwidth than our small slice of RF spectrum.

          I just can't see how wifi can scale past a niche/hobbyist service. It's half as much bandwidth as I would like, if I didn't have to share it. When 500 people within the quarter mile radius start trading mp3's (and god forbid: divx's) it will go downhill really fast.

          There's got to be a better way... but I'll be damned if I can see it.
  • Ho Hum... (Score:5, Insightful)

    by User 956 (568564) on Tuesday December 17, 2002 @05:49AM (#4905954) Homepage
    Vivato's bases reach groups of users on existing laptops and other computers, with an operating range up to 7 kilometers outdoors, the company claims. Software controlling the antennas detects Wi-Fi clients in the area and adjusts the signal across the array many times per second.

    Which is great, except when they overbook in order to maximize revenue, much like cell phone companies. [verizoneatspoop.com] Then we have spotty, intermittent coverage serving only a percentage of paying customers, as the system struggles to keep up.

    Yay technology!
    • Re:Ho Hum... (Score:5, Informative)

      by Effugas (2378) on Tuesday December 17, 2002 @07:11AM (#4906176) Homepage
      A few years back, a company came to my school to give a talk about SDMA -- Spatial Division Multiple Access. It was essentially based on the concept that, duh, a single cell phone is only one position, so the tighter a beam you could direct / detect from the phone, the more points could use the same frequency.

      The cool thing about SDMA is that as your load increases, so too (to a limited degree) does your available bandwidth. As long as people are relevantly separated from eachother, their physical positioning relative to other hosts adds disambiguatable bandwidth. It ain't perfect -- node to node crosstalk is a real problem, since your wifi cards are omni -- but they're talking about such range that there's lots and lots of omni hexes to expand through.

      Whoot to Vivato; hopefully they'll get a lower end antenna for fixed wireless clients!

      Yours Truly,

      Dan Kaminsky
      DoxPara Research
      http://www.doxpara.com
    • Everything is great until its not great, but what's your point? Oversubscription doesn't have much to do with the antenna technology.
  • Low-tech alternative (Score:5, Informative)

    by icantblvitsnotbutter (472010) on Tuesday December 17, 2002 @05:54AM (#4905974)
    A company in Sweden conducted tests with a stratospheric balloon [theregister.co.uk]. They broke 300 km (187+ miles).

    Not entirely salient, but a reminder that there's more than one way to skin a cat.
    • The amazing thing about Vivato's stuff is not that it delivers broadband over a few miles distance, but that it does so within the regulatory confines of 802.11b and without manual aiming of antennas. If you just want to deliver broadband over long distances, there are lots of ways of doing that.
    • I'm a helios [nasa.gov] man myself. Once they get those puppies finalized, you'll see small towns able to cover footprints larger then most states. Specifically, this will be much more practical in mountainous areas or simply those with lots of deep ravines.
      In Montana they've had trouble because people tend to build in narrow valleys (more water, less wind, etc.) and thereby are choosing the areas with the *worst* possible radio wave accessability. The higher you go, the less that matters.
      Rustin
    • by medscaper (238068) on Tuesday December 17, 2002 @09:49AM (#4906618) Homepage
      there's more than one way to skin a cat.

      Ok, Swedish or not, any company that can skin a cat with a balloon from 300 km away has my complete and total attention.

      • Ok, Swedish or not, any company that can skin a cat with a balloon from 300 km away has my complete and total attention.

        Awesome! I could use one, to fry those damn cats that are howling all night in the alley.

  • by JakiChan (141719) on Tuesday December 17, 2002 @05:59AM (#4905993)
    So, if the Starbucks a few blocks over installs this, is it going to stomp all over my home network? I mean a WiFi hotspot with a 4 mile radius is great, but hopefully wouldn't affect home users. That'd be like some new cellular tower killing my cordless phone...certainly not appreciated.
    • by Uller-RM (65231) on Tuesday December 17, 2002 @06:51AM (#4906127) Homepage
      I live in Portland, OR, home of PersonalTelco - a fairly well known volunteer group for WiFi access. We have more nodes listed on nodedb for the Portland metropolitan area than nearly any STATE - and take that to all states if you count all of Oregon.

      We had a big landmark case here a while ago that's exactly what you're fearing. PersonalTelco's been providing a totally free 11Mb connection to Pioneer Courthouse Square (a major hotspot in downtown Portland), and the Starbucks on one corner of the square tried to compete with them, broadcasting their pay-to-use TMobile service on the same channel.

      Starbucks ended up having to back down - they now broadcast on channel 11, and PT on 6.

      PT's a great group to get involved with - not only do they have regular meetings and stay active with local politics, they also organize a lot of things like group buys on antenna connectors and workshops on Pringles can waveguides.
    • by g4dget (579145) on Tuesday December 17, 2002 @06:51AM (#4906130)
      Over the same area, it should actually reduce interference compared to trying to cover the same area with regular access points.

      Think of it this way. With a normal access point, it's like lighting a stage with diffuse lighting: there ends up being light everywhere. This access point is intended to be like a bunch of spotlights on a dark stage: only the areas where it is aimed are actually lit up; the rest of the stage remains in darkness.

        • Over the same area, it should actually reduce interference compared to trying to cover the same area with regular access points.

          Think of it this way. With a normal access point, it's like lighting a stage with diffuse lighting: there ends up being light everywhere. This access point is intended to be like a bunch of spotlights on a dark stage: only the areas where it is aimed are actually lit up; the rest of the stage remains in darkness.

        That's a pretty accurate analogy. Having been program director at a (day time) 50kWatt AM radio station with directional restrictions I've seen powerful radio frequency radition effectively "spotlighted" to cover a quite-convoluted coverage map. Some areas being well lit and other, nearby areas being practically dark. It took four hefty antennae to accomplish the coverage pattern carved out by the FCC restrictions on our signal, but it worked very well.

        As an aside, I also saw the sad effects of this directional power on a new apartment bulding constructed on a hill less than 400 yards from the antennae in the direct path of the focused radiation. First, realize that once the FCC grants approval the radio station has a right to the frequency, more so than those who experience interference from the signal. Especially more so than new developments begun well after the station has been approved and begun broadcasting. Anyway, the poor schmucks could hear our broadcasts on the toasters (!). CD players wouldn't play (but they worked in the stores a couple miles away), forget cordless phones--forget corded phones! These people were living in the spotlight, alright. Before the apartments were completed, the foreman came to visit me at the station--the fire alarm couldn't call out to the alarm company due to interference. I called my broadcast engineer (a local area college professor who loved radio and worked more for the fun than anything else) as I hummed the tune "The Fool on the Hill." Dave came out and helped the construction crew insulate and filter the building so people wouldn't die and he even helped the toaster problem. Dave helped other nearby businesses and schools located in the direct path of the signal to filter there systems--one school couldn't use their public address system because it just played our station when activated. . .Dave fixed it.

        Boy, I miss those days! Sometimes. . .

    • "I mean a WiFi hotspot with a 4 mile radius is great, but hopefully wouldn't affect home users. That'd be like some new cellular tower killing my cordless phone...certainly not appreciated."

      Not only that, but from what I can remember, I think bluetooth uses the same frequency bads. Not only will it have the ability to bring your home WiFi range down, it can make sure your computer is so distracted by they all-powerful broadband signal you won't be able to sync your cell phone or BT enabled PDA to your computer anymore. I gueds we'll see how this turns out...

  • 4 miles? (Score:1, Funny)

    by Anonymous Coward
    That's a lot of Pringles cans.
  • by Quaoar (614366) on Tuesday December 17, 2002 @06:09AM (#4906015)
    ...until Pink Floyd uses them in concert.
  • wireless (Score:3, Interesting)

    by katalyst (618126) on Tuesday December 17, 2002 @06:12AM (#4906025) Homepage
    Interesting...... Gives rise to lots of new avenues for hacking too. Imagine to not have to be PHYSICALLY wired in. Instead... use your laptop to connect to your target server's airport and VOILA! Maybe companies will sheild their office complexes, so that a guy sitting outside the fence can't mess around with their data.
    Exciting possibities....
  • by zumbojo (615389) on Tuesday December 17, 2002 @06:15AM (#4906032) Homepage
    I could have sworn that the last time I heard "phased array" and "4-mile radius" together in one sentence something in some movie blew up.
  • by Anonymous Coward
    I need an alternative source of domain packets!

    The quality of 802.11b security implies the need to lock down the bandwidth with something.

    Could this turn into the killer app for IPv6/IPSEC?
  • Sprint broadband (Score:3, Insightful)

    by g4dget (579145) on Tuesday December 17, 2002 @07:00AM (#4906154)
    and replacement of outdated wireless technology [Sprint broadband]

    Well, Sprint Broadband works, it delivers >3Mbps, it's fairly easy to install, and it costs $50/mo. And I doubt it's a money losing venture, otherwise they'd have discontinued the service entirely rather than just not taking new signups.

    If companies will compete with Sprint broadband using Vivato technology, that would be great. But with the Vivato APs being released in 2003, I think it's at least another year away until you are going to see viable commercial broadband services based on it springing up.

    • Re:Sprint broadband (Score:3, Informative)

      by praedor (218403)

      Last I heard/read, Sprint broadband was no longer accepting new customers (This was almost a year ago I read this on their site). If you have it now it is only because you got in before the locked down the system and stopped accepting new users. Doesn't bode well for its future does it?

      • Last I heard/read, Sprint broadband was no longer accepting new customers

        Sure, that's what makes it so great :-)

        Seriously, my point is that the technology works, it's fast, and it's here now. It may be too small for Sprint, but other companies could easily take the same wireless technology and provide comparable service at a comparable price.

    • Sprint got up and going here in Salt Lake City a couple of years ago, but have discontinued their service. Seemed odd as the local geography was ideal - high mountains on each side of the valley, very few trees in the valley. LOS was available to a huge area from one access point. For a while, you would see all these diamond shaped antennae being mounted to people's chimneys, or if there was an LOS due to a tree or something, they would be on 15-20' poles. Then is just stopped. Weird.
    • Sprint costs. (Score:3, Insightful)

      by twitter (104583)
      I just happened to have a brochure of Sprint's Vision plan in front of me. There is no $50/month data plan, however $40/month will get you a big fat 20 mega bytes, with each additional kilobyet costing you $00.002. or two freaking dollars per megabyte. For $100/month the service is "unlimited." I imagine much of that money will go directly to the FCC as a result of Bill Clinton's big greedy specturm auction. I don't know about you, but I don't have that kind of money to further fund the Feds.

      It's shocking that the new administration is following the greedy, ignorant policy of it's predecesor. If such services flop, those who opposed the specturm auctions can say, "I told you so," and that will be that. It's not like the telecomunications has been a stable source of employment for most of the people working there. If the government forgives the auction debts, it will ammount to a huge bail out of big corporate interests. That's bad because it give an advantage to those who bid irresponsibly and continues the ineficient specturm use but at least it will provide service to people at something closer to its cost. If the government legislates 802.11 out of practicality, it will be a huge scandal as the only reason will be to prevent new entrants from ruining these silly third generation services. Yet this third option is the one that keeps comming up. Keeping the public from building their own communications networks, which are technically possible, ammounts to a denial of first amendment free speech rights.

      Bandwith scarcity is a lie and services that operate on that principle, metering out kilobytes of data, are a rape.

  • Guns before butter (Score:5, Interesting)

    by release7 (545012) on Tuesday December 17, 2002 @07:00AM (#4906155) Homepage Journal
    I'm afraid killing people takes precendence over informing them. The Pentagon reports that wi-fi networks interfere with their radar and further rollout of the technology must be curtailed. Read this article. [nytimes.com]
    • Actually, from what I've heard, they use radar to help commercial airplanes navigate. Furthermore, there are few crucial military domestic uses of radar other than national airspace security - that is, we need it to see if someone's sending over bombers to New York or Miami.

      I would argue that, in this case, giving priority to consumer telecommunications would result in killing people. Not the other way around.
    • by Anonymous Coward
      I hope a HARM missle does not home in on my Powerbook.
    • Thanks for the NYT article, which everyone in the world can read. I can just imagine this:

      Dear Tiger Direct,

      Do you offer volume discounts for 802.11 equipment? We are interested in many hundreds of thousands of these and will gladly pay in counterfit US dolars, oil or gold.

      Sincerely, your friend.

      General A. Henchman
      Iraqui National Air Defense
      Bagdad, Iraq.

  • by pariahdecss (534450) on Tuesday December 17, 2002 @07:21AM (#4906186)
    I am all for the propagation of this technology. I live in an area with no broadband access whatsoever . . . .just don't put the radiating tower in my backyard . . .my kids are weird enough without growing extra appendages
    • My physics sucks - anyone got a decent overview of the relative densities coming from Mobile phone masts and these things?

      Recently a mobile phone mast was stopped from being erected on my street due to 'concerns over radiation levels' despite the background radiation being some 100x as strong in peoples homes.
      • Don't need physics to understand. Look at the cell antenna's ratings if you were to buy one. Beam pattern and power are what you choose from. They measure them in kilowatts and directional gain.

        Your microwave puts out a kilowatt. If its a good one.

        Its cold this winter. Are you sure a few kilowatts in your back yard are that bad?
        • Who doesn't need physics to understand thins? Me? I beg to differ. I did a couple of years of Physics at uni and I dont have a quick intuitive way to suss the potential effects of this kind of kit.

          My microwave may 'put out' a kilowatt but whats the apparent energy at 10m, 100m? I have a sneaky recollection that physics has some equations for that kind of shit! I've just forgotten them. They tended to involve squares and cubes and roots!
          • Who doesn't need physics to understand thins? Me? I beg to differ.
            The reason you don't need to know physics to understand it is that it can be explained by simple geometry. If you have a 1W radiator (antenna) that is omnidirectional, only a small amount of power will be radiated in any given direction. So when the AP is communicating with a specific node, most of the power is wasted.

            If you use a directional antenna, allmost the transmit power is sent in one direction, so if that's where the receiver is, the same 1W gets more power to where it's useful.

            A phased-array antenna can be directional to an arbitrarily chosen direction, so what the Vivato AP does is readjust the phased-array direction for each client.

            My microwave may 'put out' a kilowatt
            As others have pointed out, it doesn't do that, but assuming it did...
            but whats the apparent energy at 10m, 100m? I have a sneaky recollection that physics has some equations for that kind of shit!
            The inverse square law. This was pretty obvious to me years before I took physics. Microwaves aren't doing anything unusual, just think about a light bulb. If you put a sheet of paper 1 foot from a light bulb, it will collect 4 times as much light as if you put the paper 2 feet from the light bulb.
        • Your microwave doesn't put "out" a kilowatt. The kilowatt stays inside the microwave. Actually, the energy is being transferred only when there is some food containing water inside the microwave. And even then, you have to apply extra effort (rotate the food and the tranceiver) to transfer more energy to the food.

          The radiation is shielded on 5 sides of the oven box by the metal case and the door also has conductive shielding. So, even if you place parts of your body next to the microwave, you won't be exposed to the radiation.

          I read somewhere that they placed people inside big microwave ovens and applied moderate amounts of power. The test subjects experienced a warm fuzzy feeling...
          • Your microwave doesn't put "out" a kilowatt. The kilowatt stays inside the microwave.

            Absolutely right. I just want to clean up a detail...

            And even then, you have to apply extra effort (rotate the food and the tranceiver) to transfer more energy to the food.

            No extra effort is needed. The reason they rotate the food is to even out the heating. Microwaves tend to create hot spots and cold spots in the food. Either way the energy transfer is about the same.

            -
            • No extra effort is needed. The reason they rotate the food is to even out the heating. Microwaves tend to create hot spots and cold spots in the food. Either way the energy transfer is about the same.

              That too. However, I think that the microwave energy is not generated homogeneously in space. There are maxima and minima of energy, corresponding to nodes and crests created by the electromagnetic wave, similar to the sound wave in a box creating dead and alive spots.

              So, if the food and tranceiver were not rotated, the food might not be located at a maximum of the wave oscillations, so the transfer of energy wouldn't be optimal. If the food and tranceiver are rotated, the food will at least pass some of the maxima some of the time.

              • There are maxima and minima of energy, corresponding to nodes and crests created by the electromagnetic wave

                Exactly right. You get standing waves, hot spots and dead spots.

                the food might not be located at a maximum of the wave oscillations

                In a microwave the maxima and minima are about 1.2 inches apart (3cm). It you're cooking anything bigger than a marshmellow you're going to hit a maxima no matter where you put it. The rotation just smooths out the cooking on the inch-scale.

                -
          • Also the kilowatt is a nominal figure. In actual usage, depending on the model, output can be 8.3% to 22% [bris.ac.uk] below the nominal figure. This is why the instructions on your tv dinner always say 'microwave ovens vary'.
          • Your microwave doesn't put "out" a kilowatt.

            You haven't seen my microwave have you? Waveguides make wonderful antennas...
    • I am all for the propagation of this technology. I live in an area with no broadband access whatsoever . . . .just don't put the radiating tower in my backyard . . .my kids are weird enough without growing extra appendages

      I understand that you are trying to be funny, but I see sooooooo much cell tower ignorance at zoning hearings.

      First of all, people (including zoning officials) do not understand that radiation levels are not something that can keep out cell towers. That is an area which has been pre-empted by federal law.

      Second, they do not understand that cell phone radiation is not ionizing radiation. It cannot break chemical bonds and cause genetic mutations. It could cook you if you stood close enough and it broadcast at a high enough power, but it cannot cause cancerous changes. These people hear "radiation" and think "Godzilla" not "reading lamp". It's just blatant science ignorance.

      GF.
      • Ionizing mutagenesis is not the only method to induce cancer.

        Ignorance of biology is unfortunately causing a lot of otherwise well informed physicists and engineers to make these statements like: "it cannot break chemical bonds and cause genetic mutations".

        The fact of the matter is that it is entirely theoretically possible to cause mutation and cancer by selective heating of enzymes in cells. Namely you simply have to denature or inactivate the enzymes responsible for DNA repair (DNA is damaged all the time) or inactivate the enzymes responsible for apoptosis or other important cellular functions. This can be done by selective heating, which is in fact exactly what microwaves do. Even if you don't wind up with a cancerous tumor you might wind up with a "benign" brain tumor. Not fun.

        There is no theoretical argument about ionization that will make this problem go away. It can only be determined by experimentation and epidemiology.
  • 4 miles? That's all fine and dandy, but think of the implications aside from being able to connect in "pocketed" areas.

    Too many "off-limits" zones in the suburbs of major cities for this to be any good. Considering the fact that upwards of %80 of the people that'd benefit from this live in such suburbs. PD's, FD's, Hospitals, etc. are all considered to be zones absolutely off limits to any such interference this would cause (suburbs are totally PACKED with these, There are 3 PD's and 2 FD's, as well as 2 Hospitals within a 4 mile radius of my house). That's FCC regulation that's been around since the '30s, and they're sure as hell not going to change them now.

    Given the method they'd have to use to make sure they aren't broadcasting in that area, you end up with 1 or 2 degree swaths of no service areas eminating from the tower. May not sound big, but after a mile or so it gets to be the width of a city block.

    I'm all for this, but a better solution would be to use smaller and cheaper arrays. Just find a way to lower the latency and it'd be even better.
    • What you describe was wat Metricom/Aerie/Whoever tried to do with Ricochet. Instead of a bunch of towers covering large cells they used their little repeaters to make micronetworks. Instead of having a huge swath of city not covered by a spot beam they just neglected to stick repeaters up in that area.
      • Rather funny considering that the PD and FD is one of Ricochet's major consumers. (Think NYC after 911 when the service was activated for PD and FD use.)
        • The parent post was regarding consumer access, not public service access like PD and FD. The major reason hospitals don't want you running around with an Airport card in your laptop is because their monitoring systems use the same frequencies. Nurses not knowing a dude in the intensive care ward is having a heart attack because some jackass is sitting in the lobby playing Quake on his laptop would be a very bad thing.
          • Last I checked, playing Quake, even on a laptop, didn't make someone a jackass.

            I think you may have missed my point. I was expressing amusement that public service's are finding use for a consumer system that is regulated such that it won't 'interfere' with, or be useable in, the function of public services. The correct conclusion to reach is that it would have been much better to allow the services to co-exist and benefit eachother (more so the public service sector).

          • The major reason hospitals don't want you running around with an Airport card in your laptop is because their monitoring systems use the same frequencies.

            If they've got mission critical wireless systems, WTF don't they run them on their own exclusive licensed frequencies?

    • PD's, FD's, Hospitals, etc. are all considered to be zones absolutely off limits to any such interference this would cause... ...better solution would be to use smaller and cheaper arrays.

      The point of the phased array is that it causes far less interference. It can get coverage to far more area while staying within the exact same limits to hospitals, PD's and FD's. It also gives you far more control of the coverage. Even if you have a "1 or 2 degree swath" on the far side of a hospital you can cover it with a second tower 3 miles away in a different direction.

      The current implementation uses a fairly localized phased array to create beams. If they were to coordinate widely separated antennas they could do much better than beams, they could give pinpoint coverage. Almost like placing an ultra-weak antenna on the target's shoulder. It also becomes possible to actively zero-out the interference to hospitals with a pinpoint inverse signal.

      They aren't up to pinpoint coverage level I described, but it will come. The current phased arrays are still far better than regular antennas.

      -
    • PD's, FD's, Hospitals, etc. are all considered to be zones absolutely off limits to any such interference this would cause

      So it's illegal to use 802.11b, a 2.4GHz cordless phone, or a microwave oven in the same region as a fire department, a police department, or a hospital? Quite frankly, I think you're wrong and yours is the first such claim I've heard regarding the use of unlicensed spectrum. Please provide a reference, as it appears you believe that the FCC was quite irresponsible in allowing retailers to sell such dangerous devices to the general public.
  • by InfiniteWisdom (530090) on Tuesday December 17, 2002 @08:05AM (#4906277) Homepage
    802.11 has been shown [1] to be completely insecure... have these security issues been fixed? From my reading of the paper, all that really needed to be done to fix most of the issues was to switch from OFB mode to CBC or CFB [1] Nikita Boristov, Ian Goldberg, David Wagner. Intercepting Mobile Communications: The Insecurity of 802.11. SIGMOBILE 2001. http://www.berkeley.edu/isaac/mobicom.pdf
    • Security issues will never, ever be addressed but fear of wireless communications is baseless and stupid. Wireless is no less secure than any other part of the internet. When you hook up to it, people can see your machine and may try to hack it. The concerns you have about inteception exist for all forms of communications. An interloper can even listen to a stand alone machine unless that machine is operated in a windowless perfect Faraday cage on battery power.

      The only answer is to use an easy to customize, stable and relativly secure operating system and lock it down. This will lower the chances of your machine being owned by someone else who will then use it to search for content of interest, store mp3s, movies and kiddie porn, or to harrass others, yet not throw out the whole purpose and promisse of the internet: the sharing of information and computing resources.

      I'm very very tired of people transfering their eXPerience with worm, virus, hole plauged operating systems to "security" of the internet. Not every machine in the world is brain dead enough to run an email client as root and automatically execute attatchments. Some people use freely available secure communications packages like OpenSSH. Get a clue people, especially you, Uncle Sam.

      • You're an idiot basically. I'll bet you never even read the paper I cited. I don't know why I even bother responding to your drivel, but still...

        802.11 was designed to provide confidentialty, access control and data integrity. And the paper cited demonstrates that neither of the three are achieved (in very practical attacks... not something involving million-dollar machines)
        • You're an idiot basically.

          Name calling is nice, thanks asshole.

          I'll bet you never even read the paper I cited.

          You might try a valid link to something that's not a huge pdf file. Your link did not work, and I don't like multi megabyte pfs where text can explain the concept.

          I don't know why I even bother responding to your drivel, but still...

          I know why, let's look and see.

          802.11 was designed to provide confidentialty, access control and data integrity. And the paper cited demonstrates that neither of the three are achieved (in very practical attacks... not something involving million-dollar machines)

          Aha, you respond because you are a troll. That's not the stated goal of 802.11, now is it? Would you mind responding to the fact that all communications are insecure? It's all very nice of you to call me an idiot, but it would be better if you informed me. As I see things now, you don't need million dollar equipment to tap a phone line, a cable, listen to microwave tower transmisions or most other forms of current communications. None of these forms of snooping takes much more effort than setting up a 802.11 bug. Others with larger budgets can spy on stand alone machines, but even there, I doubt that off the shelf light analysis equipment costs millions. You could hire a competent engineer to build one for you for $50,000 in a year plus a few equipment costs. Encrypted communicatins over 802.11 works as well as encrypted communications anywhere else.

  • Ken Biba? (Score:4, Interesting)

    by sczimme (603413) on Tuesday December 17, 2002 @08:17AM (#4906306)

    Given the qualifications and history of Ken Biba listed in the article

    Biba started in security and networking R&D 30 years ago with Mitre Corp. and was a member of the Advanced Research Projects Agency Transmission Control Protocol (TCP) Working Group

    I wonder if he is the same Ken Biba that worked on/devised Mandatory Access Control (MAC) and the Biba Integrity Model.

    There is a good description of MAC here [freebsd.org], and an explanation of the Biba Integrity Model here [tml.hut.fi].
  • Ewige Blumenkraft (Score:3, Insightful)

    by Graymalkin (13732) on Tuesday December 17, 2002 @08:50AM (#4906393)
    So how exactly do people with pie in the sky Wi-Fi plans intend to overcome 802.11b's inherent scalability problems? How many people can one AP REALLY serve?

    From my experience I'd say that answer to that question is not very many. Having more than a couple people on a single AP is a recipe for pain and suffering. As the number of users on an AP increases so does the chances of packet collisions. As collisions increase the viability of the network decreases and you eventually reach a collapsing point where the network is unusable. A corollary to that rule then would be the larger your coverage area the higher a chance of collisions and thus a higher chance of the network collapsing.

    You run into a similar problem with 802.3 which is solved by switching the network. With a wireless network you don't have the ability to add a switch in the middle of the network to keep the number of collisions down to a minimum. You're only got a bunch of nodes waiting their turn to talk. Switching channels isn't an option because APs can only serve particular channels.

    With a coverage area of four miles then, the number of potential collisions on a channel is pretty high because your entire customer base could be in that four mile coverage area. Sweeping a broadbast between different nodes doesn't do much good on their end where all the static from other connections is an issue. On current networks you've got a small number of users because your coverage area is pretty small so problems aren't evident. You don't have problems on a wired network with only a 5 port hub either.
    • Re:Ewige Blumenkraft (Score:4, Informative)

      by rjamestaylor (117847) <rjamestaylor@gmail.com> on Tuesday December 17, 2002 @10:23AM (#4906788) Homepage Journal
      What part of "Wi-Fi Switch" did you not understand? From the site [vivato.net]:
      • Vivato's Wi-Fi switches deliver the power of network switching with Vivato genius radio antennas. Vivato's switches use phased-array radio antennas to create highly directed, narrow beams of Wi-Fi transmissions. The Wi-Fi beams are created on a packet-by-packet basis. Vivato calls this technology PacketSteering(TM). Unlike current wireless LAN broadcasting, Vivato's switched beam is focused in a controlled pattern and pointed precisely at the desired client device. These narrow beams of Wi-Fi enable simultaneous Wi-Fi transmissions to many devices in different directions, thus enabling parallel operations to many users - the essence of Wi-Fi switching. These narrow beams also reduce co-channel interference, since they are powered only when needed.
      • Vivato's Wi-Fi switches significantly increase the range of Wi-Fi. Rather than transmit the radio energy in all directions, Vivato's PacketSteering concentrates the same amount of energy into a narrow, long beam. This beam is effectively a high-gain antenna that is formed for the duration of a packet transmission. The result is extreme range - extending the reach of Wi-Fi from tens of meters to kilometers.

        Another key attribute of switching is preserving compatibility with standard client devices. Vivato's Wi-Fi switches deliver increased capacity, range and security to standard Wi-Fi clients based on the IEEE 802.11b, 11a or 11g standards. With increasing capacity and range, Wi-Fi switches are more scalable than Wi-Fi traditional micro-cellular implementations and are managed in much the same way as Ethernet switches for easy adoption and widespread deployment.

      • I SPECIFICALLY said that the access point of the equation is not the problem. The problem exists on the client end without phased array antennas. If you have fifty people all in the same area with their cheapo dipole antennas chattering away on the network the whole thing becomes inusable. It doesn't matter if the head end has some cool steerable spot beam. Having a head end switch from Vivato is like plugging a bunch of nodes into a hub and then plugging that hub into a switch to talk to other hubs.
          • So how exactly do people with pie in the sky Wi-Fi plans intend to overcome 802.11b's inherent scalability problems? How many people can one AP REALLY serve?

            From my experience I'd say that answer to that question is not very many. Having more than a couple people on a single AP is a recipe for pain and suffering. As the number of users on an AP increases so does the chances of packet collisions. As collisions increase the viability of the network decreases and you eventually reach a collapsing point where the network is unusable. A corollary to that rule then would be the larger your coverage area the higher a chance of collisions and thus a higher chance of the network collapsing. . .With a wireless network you don't have the ability to add a switch in the middle of the network to keep the number of collisions down to a minimum. . .On current networks you've got a small number of users because your coverage area is pretty small so problems aren't evident. You don't have problems on a wired network with only a 5 port hub either.

          Later. . .
          • I SPECIFICALLY said that the access point of the equation is not the problem.
          First, you did not SPECIFICALLY say the problem was with the client...your post (the one I saw and responded to) addresses the AP and NUMBER of clients. Second, your statement: "With a wireless network you don't have the ability to add a switch in the middle of the network to keep the number of collisions down to a minimum" and your analogy to a "5 port hub" shows you didn't read or comprehend the advance claimed by Vivato--it is a Wi-Fi SWITCH!

          But, I do admire your commitment -- if one is going to dig themselves into a hole, they might as well make it deep! :)

        • With a four-mile range, clients could be up to eight miles apart. You can rest assured that clients eight miles away from each other will not be interfering with each other. One assumes that they have to be within traditional WiFi range before they start to interfere.
        • Pringles Can Antennas [sfsu.edu]!!

          or maybe these [dlink.com] much nicer looking clones from DLink.

          ELiTeUI Out.
    • Having more than a couple people on a single AP is a recipe for pain and suffering. As the number of users on an AP increases so does the chances of packet collisions.

      This is not a problem. Lets seperate it into three problems. (1) The AP sending packets to the mobiles. (2) The AP detecting packets from several mobiles. (3) Mobiles interfereing with each other.

      The phased array is behaves like several access points with seperate high gain directional antennas. This works on both transmission and reception. The the AP can beam simultaneous packets out, so (1) does not cause collisions. The AP can read simulaneous packets from different directions, so (2) does not cause collisions.

      I think you are worried about (3). If you have a fixed number of people in a fixed area it makes no difference weather or not they are on the same AP.

      Putting a given set of people onto the same AP only matters to the the AP, and the phased array solves that. (Unless they all stand in a line pointed at the AP :D)

      -
    • 802.16 looks like it ought to support more clients/base station than 802.11 because it uses TDMA instead of CSMA/CA. This Vivato antenna has the advantage of being compatible with existing equipment, though.
  • Makes sense that you can build a big-ass AP that will provide a large 802.11 blanket, but how is my laptop's little antenna going to talk back to it?
    • It turns out that if one of the antennas in the link is high-gain, then it is high-gain on transmit *and* receive.

      Consider cell phones.. the phone has this tiny little antenna, but the cell site has a big honking high gain antenna that concentrates the RF in a pancake, and in some case in just more-or-less one direction -- e.g. towards the highway.

      Hence, this thing works with standard laptop cards. Pretty neat, eh? jeff
  • by goodEvans (112958) <devans&airatlanta,ie> on Tuesday December 17, 2002 @09:04AM (#4906427) Homepage
    The Terminator: The .45 Long Slide, with laser sighting.
    Pawn Shop Clerk: These are brand new; we just got these in. That's a good gun. Just touch the trigger, the beam comes on and you put the red dot where you want the bullet to go. You can't miss. Anything else?
    The Terminator: 802.11b Phased Array rifle in the forty watt range.
    Pawn Shop Clerk: Hey, just what you see, pal.
  • If your Wi-Fi network extends 4 miles, then the terrorists have already won.
  • I don't care about all these cool _wide_ _open_ _land_ solutions!

    What about all the people who can't even see their neighbor's house? I want to set up a WISP in my neighborhood, but I have no direct line of site to anybody.
  • by grub (11606) <slashdot@grub.net> on Tuesday December 17, 2002 @09:58AM (#4906661) Homepage Journal

    Whoa... Every time I hear that term it's on Star Trek and in regards to some huge weapon of mass destruction.

    /me wraps his head in another layer of tinfoil.
  • by Anonymous Coward on Tuesday December 17, 2002 @10:22AM (#4906778)
    Please guys, this techonology is NOT about splattering megawatts all over town!

    It is about aiming a low power beam in the right direction using a smart antenna AND that same smart antenna is a better listener.

    It's a high-tech equivalent of a parabolic antenna and it is adjusted to radiate the same power at a distance as a normal omnidiretional antenna would do. That's what the FCC require in order to approve an antenna.

    It's a common mistake to think that range=power. Note that this is a two way operation.

    You also have to be able to hear the other guy, right? That takes good listening skills = a directional antenna.
  • by sdjunky (586961) on Tuesday December 17, 2002 @10:49AM (#4906945)
    Now if Only I can calibrate the deflector dish to use the dilithium crystals to create a Tachyon pulse...

    Where is Spock when you need him?

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