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Wireless Networking Hardware

Open Spectrum: Toward Ubiquitous Connectivity 95

Posted by michael from the always-on-always-online dept.
obiwan2u writes "ACM's Queue magazine has a moderately dense article describing how new intelligent radios may free up under-utilized spectrum bandwidth, possibly providing solutions to the last mile bottleneck."
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Open Spectrum: Toward Ubiquitous Connectivity More

Open Spectrum: Toward Ubiquitous Connectivity

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  • Last mile, what's it worth? (Score:3, Insightful)

    by ObviousGuy ( 578567 ) <ObviousGuy@hotmail.com> on Thursday June 12, 2003 @09:11PM (#6187300) Homepage Journal
    If you live in the wilderness, is getting broadband really a priority?

    As it is, most residential areas have telephone coverage. As the internet gets more mature, the need for broadband lessens because of improvements in packet technology and of course data compression. What was possible 5 years ago on a 56K modem doesn't even compare to what you can do with the Internet today with even a lowly 28.8. The improvements are just so vast.

    So what's the big deal with broadband? So you get to view Slashdot 2 seconds faster. So you get to look at the daily news on MSNBC 2 seconds faster. So what? We are talking about lengths of time that don't even register on our awareness.

    Look, people who live far away from civilization chose that lifestyle. One big reason was to get away from all this technology crap. Let those hermits live in peace. Not everyone needs or wants the latest and greatest, sometimes they just need the simple and natural.

    • Re:Last mile, what's it worth? (Score:4, Insightful)

      by Raindance ( 680694 ) <johnsonmxNO@SPAMgmail.com> on Thursday June 12, 2003 @09:27PM (#6187356) Homepage Journal
      It's tough to think of meaningful applications for the Last Mile because it's not here yet; impliment it comprehensively and watch the machinery of capitalism work and think up thousands of applications for it. Of which a few will probably be meaningful.

      Also, I'm not sure that
      "As the internet gets more mature, the need for broadband lessens because of improvements in packet technology and of course data compression. What was possible 5 years ago on a 56K modem doesn't even compare to what you can do with the Internet today with even a lowly 28.8. The improvements are just so vast."
      Could you qualify this statement, as improvements in packet technology (IPv4 vs IPv6) have actually increased the likely overhead of packets, and though we've come a long way in sound/video compression, we've not made much progress in generic data compression (the majority of overall and residential packets, vs streaming audio/video) in the past 5 years AFAIK.

      If you build it, they will come. Improving compression ratios is at best evolutionary in change, not revolutionary as the Last Mile potentially is. And it is definitely that.

    • Re:Last mile, what's it worth? (Score:5, Insightful)

      by rabiteman ( 585341 ) on Thursday June 12, 2003 @09:33PM (#6187375) Homepage
      We are talking about lengths of time that don't even register on our awareness.

      Sir, I find it hard to believe that you've used dial-up internet access recently. Either that or you haven't used broadband recently, since you claim to notice no substantial difference between it and dialup. The length of time required to "register on our awareness" depends heavily on the circumstances surrounding it, and on how long we expect an activity to take. When it comes to pages loading, using broadband gives you the expectation that the activity of loading a page will take almost no time. When you use dialup and, suddenly, the time you're required to allot to page loading is much more than what you expected, you are all too painfully aware of the time differential.

      In my apartment, on my cable modem, mapquest [mapquest.com] takes a second or two to load. The last time I was at my parent's house, using 56k dialup, mapquest took over 20 seconds to load just the front page. Actually downloading directions somewhere took over a minute. Granted, under certain conditions, I don't notice the passage of a minute of time, but staring at a map that's being downloaded isn't one of those conditions.

      The culture shock of dialup is part of why I use the internet so little when I'm home... I'd rather have no access at all than slow access. ;)

      • the only practical workaround... (Score:4, Insightful)

        by zogger ( 617870 ) on Friday June 13, 2003 @09:04AM (#6189918) Homepage Journal
        ...that I have found is tabbed browsing. I'm one of those on a slow staticy rural dialup, just too far away from the nearest telco switch, and even then, the cost would be prohibitive for what they offer for *dsl. Well, to me anyway. 56k modems just slap don't work, I have three of them, they lose connectivity so quickly that they are useless. Next down I use a 33k modem, and only when the weather is perfect. That's my main modem, fairly robust and reliable, but again, the minute the lines get more static and noise, poof, they dropconnection. Right now, the only way I can even stay online is by using a 14.4 modem, as it is storming out. This might last all summer, just depends on the weather. The workaround is social,there is no actual hardware solution that I think I can do (satellite is out, that's one thousand bucks or something) I just load various tabs with content, then go do something else. It takes minutes sometimes to load pages, even with images turned off,etc. I will say that xmms playing radio mp3 streams is very nice no matter what,it gives me one more cool *thing* to do with the net, I only listen to lower bitrate talk stations, beats the pants off any other streaming tech out there, real, quicktime, windows media, winamp, etc. The old mac classic soundjam does the next best job on slow connections with mp3s. Of course I have a lot of other "real" radios as well,I just like the ability to get exactly what I want off the net, I mean this thing is sitting here turned on anyway, one less hardware device to power up.

        I would really like broadband, I'll pay x-amount to me reasonable money for it WHEN it becomes avaialable, but yes, I won't trade my other real life interests and advantages I enjoy about living rural "just" for broadband. I lived heavy urban for years, nothanks, I'll pass now, did my time in crime city, constant loud, stinky (cities literally stink, you don't notice it until you've been away for awhile and go back into one), expensive this or that, etc. There are a lot of advantages, but a lot of disadvantages to urban life. And vice versa, neither is "perfect".

        OK, back to connectivity. Whichever company that comes up with an easy to use, reliable and cheap universal wireless "solution" for that last mile WILL get my business, and there's millions of people out there who will buy it as well. Perhaps it's a niche market, but what ain't once you get down to it? Look at what happened with small dish cheap satellite TV when cable wouldn't go there to that last mile and when some mastermind noted that large dishes and hardware were too expensive for a lot of people, there was a niche market for something besides 1.5 fuzzy channels of over the air tv option, rural people jumped on it in droves. They weren't willing to move to the city for a lot of clear TV, that still didn't mean they didn't like to have some TV, a market that went begging for a long time.

        It's like cheap downloadable music tracks, a market that went begging for years, literally went begging, people-potential customers- going "here, take our money we want this product". They got told to go &*&&^k themselves by the music monopoly. It was that insulting, hence the popularity of napster and etc and yada yada yada. Half of it was to just insult those bungers right back. Now how many songs has apple sold so far, because all they did was respond to a market going begging??

        I will guarantee ANY of you companies or developers out there, you offer a wireless last mile that WORKS, that doesn't cost outrageous money, and that provides even a slightly more reliable and faster connection than most-alleged "56Kbps" rural dialup, you'll get rich, you'll get obscenely stinking rich, you have millions and millions of potential customers out there.

        Sometimes the bean counters are wrong. A lot of times they are, really, they over estimate one potential profit maker while completely ignoring another one, and usually because the new potential is just that, new, or they aren't aware of it. I sincerely doub
    • Well, there are limits to the capability of compression, and the phone lines are, ultimately, just not as good as "broadband" last mile solutions.

      Also, there's more to life than searching the web. I, for one, do a lot of work from home, and although a cable modem is decent, it sure would be easier to work remotely with higher-speed, lower-latency connectivity. More people could run their own web/ftp/whatever servers out of their homes.
      • LOL. Sorry, just thought it was funny:

        the phone lines are, ultimately, just not as good as "broadband"

        I have ADSL, which is over the phone line. "the phone lines are, ultimately, just not as good as the phone lines"

        I always thought that was weird. Modems are so slow because they have to use the crappy phone lines, but ADSL is fast because it uses the same crappy phone lines? Ok :)

        • Re:Last mile, what's it worth? (Score:5, Informative)

          by etcshadow ( 579275 ) on Thursday June 12, 2003 @11:46PM (#6188067)
          <i>I always thought that was weird. Modems are so slow because they have to use the crappy phone lines, but ADSL is fast because it uses the same crappy phone lines? Ok </i>

          ADSL doesn't use just any phone lines. I think that less than half of the houses in the US are wired with high enough quality lines to support DSL. Also, the drop-off of bandwidth as a function of distance from the phone company's substation is pretty rapid. If you live in even a fairly spread-out suburb, chances are you can get crap DSL at best, let alone semi-rural or full-blown rural areas. Oh, and when I say "phone lines" I don't just mean the twisted pair running into your wall (although the physical wire quality is part of it), I'm talking about the various switching hardware upstream, too. Do you think that Podunkville doesn't have DSL available yet just because the phone companies are jerks? No, it's because it's an expensive investment for them to upgrade their "lines" to provide DSL.

          So, no, ADSL doesn't use "the same crappy phone lines"... it uses different, not-as-crappy phone lines.

          Also I put "broadband" in quotes because it's not entirely a very well defined term. (Yes, I know that there have been a few things attempting to define the term in various places... even a lawsuit over the use of the term, but it's not settled yet.) You can call pretty much anything from 128k up "broadband", but its really not in the same ballpark as 512k or 1M (or possible higher, with various new technologies like 802.16 MAN).

          Besides, all that said, I consider your ADSL (via phone lines) slow because I have a cable modem. :-D
          • Also, the drop-off of bandwidth as a function of distance from the phone company's substation is pretty rapid.

            Frankly, I don't know what the hell you're talking about. It must suck to live in the US, that's all I can say.

            I live in a medium sized Canadian city, and ALL ADSL customers get 150k/s down, 50k/s up. Regardless of location. Oh yeah, and I've looked and looked and looked, but I can NOT find availability data on my ISP's website. I can only assume this to mean that ADSL is available to the entire
          • AFAIK, DSL is only an upgrade of the ISP's hardware. It still runs over j.random copper wire.
    • about 7 years ago I was playing some real audio streems while downloading netscape 4 and chatting at the same time,on a 33.6 modem, about a year ago before (I got cable) on 56k I was lucky to download and chat at the same time and then I was getting download rates in the 28k range, so many people have internet now compared to 5 years ago that most of the dial-up isps cant handle it, when I got broadband it spoiled me so much downloading 700 meg files in hours insted of days. as time goes on and people relis

    • Re:Last mile, what's it worth? (Score:5, Insightful)

      by corsec67 ( 627446 ) on Thursday June 12, 2003 @09:35PM (#6187389) Homepage Journal
      One word for you, and this is from a user on a *shared* 28.8 modem, "Flash"

      Compression might have gotten better, but the size of websites is incredible!!!

      Stupid web designers can overcome any technological gains, and easily. I have seen a website that used JAVA for OnMouseOver(), not JavaScript. Annoying bitch. Another great (bad) example is http://www.swatch.com/internettime Flash used with no way to navigate outside that flash.

    • Re:Last mile, what's it worth? (Score:5, Interesting)

      by El ( 94934 ) on Thursday June 12, 2003 @09:36PM (#6187392)
      Yes, broadband IS a priorty in rural areas. I own a property for which it costs over $10,000 to run a cable to the house. I assure you, wireless broadband would be not only faster, but cheaper. (The best I can do there now is ISDN)

      • Re:Last mile, what's it worth? (Score:4, Informative)

        by Phishpin ( 640483 ) on Thursday June 12, 2003 @10:07PM (#6187540)
        I live in a similar situation. I live in rural southern Indiana and it would cost thousands of dollars to get a cable to my house. Everything except the phone and electric lines is wireless.

        I do have wireless broadband. Its from a local company (Ohio Valley Wireless cable). The service is called Speedex and it uses a Hybrid [iowave.com] 3.5GHz microwave link. Its $50 a month for service that usually averages to about 95KB/s downstream and 16KB/s upstream. Its got a 30-35 mile radius from the tower, so the coverage is pretty darn good. To my knowledge, its been down only once in the year I've had it, and that was for 45 minutes. AT&T botched up their T lines.

    • Speaking as someone who lives in the wilderness... (Score:5, Insightful)

      by poptones ( 653660 ) on Thursday June 12, 2003 @09:36PM (#6187395) Journal
      The answer, for some of us, is "yes, absolutely."

      Wanting to live in a cave doesn't always mean one wants to turn his back on knowledge and information.

      So what's the big deal with broadband? So you get to view Slashdot 2 seconds faster.

      Apparently you live in a different kind of "wilderness." Sorry for you, but being a hermit doesn't have to mean being a luddite. Nor does choosing to live in a "green ecosystem." Modern technology presents all sorts of new opportunities - even to those who choose to separate themselves from the greater of "society." In fact, that's the best part of it.

    • If you live in the wilderness, is getting broadband really a priority?

      Sure. I used to live in the wilderness of Brooklyn. Now I'm in a New England town of 3000. Had to find a place with a DSL connection as good as I had there. Managed to. I get the same 35ms pings to Manhattan I used to. If I could be even more rural and get those pings, I just might. I do remote administration for clients in Manhattan. Also have some servers here. This works as well as being in Brooklyn, the living costs are a hell of a
    • not true. I live in a town of 1200 and we don't have even decent ISPs for the most part, much less fast download speeds (you try to download an ISO image or a new kernel source when you're on a 28.8 connection and tell me how you like it.) I know of a county capital a few counties over that most people are lucky to connect at 26, and get to pray it stays connected. Live out there for a bit and then you can say all you want. that was spoken like a true asshole.
    • What the hell are you talking about?

      If all you do is read /. on your dial up connection, then fine, you don't need broadband. The rest of us are chewing up 3+ gigs a day doing a hell of a lot more. I am;
      Running web servers, game servers, swapping files, downloading video from work, doing CVS checkouts, downloading ISOs, uploading ISOs, looking at porn, streaming audio, oh, and reading /. All while chatting on the phone. What's the big deal with broadband!? I'd sell my firstborn before going back.

    • Ummm...beg to differ (Score:3, Informative)

      by bethanie ( 675210 )
      Well, I wouldn't say we live in the "wilderness" per se -- we're a short 15 minutes from the county seat, and lord knows Wal-Mart is just 10 miles down the road! But it sure would be nice to be able to hook into the DSL that's 3 [road] miles away.

      A modem speed of 56K isn't the end of the world, but when that's all the bandwidth you have and you're both surfing at once, it can be torturous. I use the Net a LOT less since moving to the country (and away from our cable modem). Believe me -- I notice the diff
      • Another issue for us is that the max upload speed we're getting is 33K -- try e-mailing pix of the baby to parents on the left coast with THAT!! It takes *hours*.

        Have you tried compressing the pictures?

    • Wrong again! There is a finite amount of entropy you can squeeze out of a given channel... again, most compression relies on finding patterns in data through heuristsics, and the laws of diminishing returns come into play. you can't always wring any more bits out of a stream, even if you had a 64K node beowulf cluster dedicated to your 56k modem. You dont seem to understand how bandwidth works... there's no way in hell your going to reencoded a 1.3 Gbps HDTV over IP stream in real-time over even a T-1
    • Last mile's worth a lot. Look what it's got us so far with POTS:

      Voicemail/answering machines to pick up while we're out
      BBSs to chat with other folks
      Faxes to get documents sent to us very near "instantly"
      Internet access to do all of the above and more

      Replace a phone line with a dedicated Internet connection and the hermits are no worse off.
    • "One big reason was to get away from all this technology crap."

      Heh. Hardly. I like my technology. It's the morons that usually congregate around it that bug me.
    • I know, after getting cable I deeply regreted the decision. I mean I didn't even notice that I downloaded 3 complete Redhat ISOs in 2 hours compared to the week it took with dialup (not including 2 disconnects that occured when I wasn't at home). And when I download 100 meg game demos on cable in a few minutes compared to the hours it took on dialup, I don't even notice. Oh and with online gaming, you can't even tell that your shots are going exactly where you want them to go, exactly when you want them
    • I disagree. Just because someone elects to remove himself from crowded meatspace does not mean that they don't want fast & reliable access to information. In fact, a fast datastream would probably be desired, to keep more in touch with loved ones or other significant entities. In the crowded conditions most of us live in, most of our time is spent in reaction to our environment (lines, traffic jams, pollution, etc.), while living out in the boondocks may free that aspect of our lives up a bit. If we can

  • It will never happen, but. (Score:4, Informative)

    by HiKarma ( 531392 ) * on Thursday June 12, 2003 @09:17PM (#6187320)
    I believe that today under 20% of homes get TV via over the air broadcasts. And the number is dropping. The rest get satellite or cable.

    It's clear that if we opened up all that broadcast spectrum to unlicenced use, it could easily generate enough revenue to provide free satellite or cable for those few homes still with an antenna.

    And just think of the huge value from getting all that spectrum for new technology, largely unlicenced uses.

    Of course, the National Association of Broadcasters is one of the most powerful forces in the country. They think of that spectrum as "their property" even though they are blocking much more productive use. Same with the military.

    So it won't happen, but we can dream.
    • According to the article the intelligent radios are signaling at such low power that they can use the spaces that are unused between TV stations to keep TV stations from interfereing with each other. So TV stations don't have to give up their channels.
      • Let them broadcast if they want, but let them do it in the same spectrum shared with everybody else, with the only rules being about power.

        Let anybody put up their own TV station. There should be be blessed monopolies that are the only ones to have TV stations.
    • I believe that over 99% of all statistics in /. comments are made up on the spot.

      Even if this is a valid number, 20% of households is still a huge number.

      So this spectrum is opened to unlicensed use. Where exactly does the revenue come from? Sure, companies that make devices that utilize the spectrum will make money, are you proposing these products be taxed? How then will it be decided who gets their new cable service paid for with this tax? Anyone who did not already have it? People who can't afford
      • The number I actually recalled was either 13% or 17% so I played it safe.

        The revenue would come from taking some of that spectrum and selling it off, enough to cover the costs of providing cable/satellite to everybody else (basic service only) and the rest could become open spectrum.

        It is a difficult question how to allocate the money but I would say to get it -- basic service only, local channels only -- you would have to not have cable/dbs right now, but have a TV and antenna.

        In other words, no great
        • It sounds good on the surface, but I think it would be a slippery slope. Some politician would eventually lobby that these poor kids should not be deprived of the Discovery Channel, then TLC...

          You also have the problem that cable is not available to all consumers. Would we then pay for sat. equipment so they can get basic broadcast channels via sat.? What if they can't get a sat. signal either?

          Aside from that problem, I would take another tactic. The networks/affiliates are paying for all of the infra
  • Guess not for much longer...

  • coincidentally (Score:1, Informative)

    by sailboatfool ( 178278 )
    Read the latest article about UWB by Cringly. http://www.pbs.org/cringely/pulpit/pulpit20030612. html

  • This will never happen (Score:5, Interesting)

    by thinkliberty ( 593776 ) on Thursday June 12, 2003 @09:22PM (#6187336)
    The FCC won't go for it. knowing Morse code is still a requirement to use HF ham bands, even though you can now use a computer to code/decode it. See www.nocode.org [nocode.org]
    I can't think of one positive the FCC has done for RF bandwidth in a long time. Why would they start with this?

    • Re:This will never happen (Score:3, Insightful)

      by Anonymous Coward
      The requirement that Ham Operators know morse code is perhaps a throwback to the days of WWII, or before, when the government wanted "an installed base, if you will" of radio operators that know code, for military purposes. I had a novice license first, for which I had to know 5 wpm, (1954) and then a General Class, with 20 wpm. Back then, money was tight for teens, so we had to do with 30-50 watt home-built transmitters, and to modulate the carrier (voice) was more complicated. We got into SSB, and DSB, bu
    • You know anyone who has tried to use a computer to decode morse code wouldn't say things like that. In many ways its like handwriting recognition, or ocr. Many computers have a hard time with high speed code, straight keys and bugs. Is it a g, or a m and an e going really fast - sometimes it sounds the same to me.

      There are much better digital modes to use if you have a computer - I think the most popular is PSK31.

      The CW requirement is actually part of an international treaty set up by the ITU - internatio
      • I have no problem decoding morse code with my computer, even with high speed code. I wrote my own program that automatic spell checking to close the gaps between words. It's not rocket science. That is how I learned morse code.
    • I can't think of one positive the FCC has done for RF bandwidth in a long time.

      "The starting gun was just fired in February 2002 when the FCC allowed limited use of UWB techniques in the 3.1- to 10-GHz spectrum."

      -Eyston
    • I agree that the current Republican administration would typically side with the established big business interests (ouuu, did I show my liberal bias?), but in this case the FCC also likes the entrenpenurial aspect of the 802.11b mania. From the article:

      What enabled the FCC even to consider the idea of an open spectrum has been the unexpected success of Wi-Fi (IEEE 802.11 standard) wireless LAN.... Products and services based on the 802.11b standard created a $2.9 billion industry in 2002. The FCC then s

    • You can obtain a restricted Technician Class license without knowing Morse -
      FCC Amateur Operator Classes [fcc.gov]
      If you want to use HF, you're probably going to need it because the channel allocations are so small.
      • If you want to use HF, you're probably going to need it because the channel allocations are so small.

        No, the FCC requires you to know code to legally operate on HF because an international treaty requires them to. I believe there is a proposal on the table at WRC-03 to remove that requirement.

        --zawada

    • Hi, I'm the author of the ACM Queue article on Open Spectrum [acmqueue.org]. Nice to see that it got slashdotted!

      I did a pretty major research project on Open Spectrum this year at the Center for Global Communications [glocom.ac.jp] in Tokyo that included studying the FCC's Spectrum Policy Task Force and other FCC utterings. Also was on some panels with folks from the FCC or who worked with the FCC.

      In many ways, it is appropriate to question if the FCC will make these kind of changes in our lifetimes. There is a significant portion

  • Definition of intelligent radio (Score:5, Funny)

    by allrong ( 445675 ) on Thursday June 12, 2003 @09:30PM (#6187365) Homepage

    One that filters out all talkback and boyband/britney clone pop.

    Elminate that and you've cleared up a large chunk of the spectrum!

  • This NEEDS to happen! (Score:4, Interesting)

    by Got-Tea-Rolls ( 681042 ) on Thursday June 12, 2003 @09:36PM (#6187394)
    Seriously, I live only 3 miles from the DSL limit and it angers me greatly. I have a crappy 24.4 connection. This would be great if I could be able to download stuff at highspeed. A few weeks ago I had to drive into town and go to a business of a friend to download a patch for Mac OSX that was 85mb. Satellite sucks, if this could eliminate the last mile problem that would be great.

  • Riiighht.... (Score:3, Interesting)

    by weston ( 16146 ) <westonsd@@@canncentral...org> on Thursday June 12, 2003 @09:40PM (#6187405) Homepage
    Just like modern tuning and broadcasting equipment freed up spectrum resources for low power FM....

    Tech's half the story. How the authorities see fit and/or are lobbied to allocate spectrum is the other half.

    • The Grass Roots (Score:3, Interesting)

      by poptones ( 653660 )
      But the way that needs to be answered is at the grass roots level. And one great way you ensure that is through civil disobedience - that is, lots of small communities making use of new technology in their local infrastructure and proving it works. Once you have a critical mass of support at that level, state representatives have no choice but to lobby in their behalf.

      Is there any GPL software, fairly widely used, that supports an open standard for voice communications? Sure, I know there are plenty of sta

      • Actually, I had a rather interesting discussion with someone about this. The guy was somewhat technical, but not techie (if you can appreciate the difference :) ).

        Basically, I said that with a couple of hundred geeks in a city buying wifi (or whatever wireless tech) towers and setting them up, at a cost of â600 plus the cost of the supporting pc's and the software to drive it all (probably open source, if someone sits down to write it), everyone with a wifi (or whatever) PDA or 'mobile phone' could ha

  • The myth of interference (Score:5, Interesting)

    by xixax ( 44677 ) on Thursday June 12, 2003 @09:54PM (#6187486)
    This reminds me of David Reed's idea [salon.com] that our current method of allocating chunks of the radio spectrum is as stupid as the idea of licencing colours.

    Xix.

  • a moderately dense article

    C'mon, this is Slashdot. "Moderately dense" should be "light reading" for us.

    Right?

  • Test it in unlicensed spectrum first (Score:5, Interesting)

    by Wesley Felter ( 138342 ) <wesley@felter.org> on Thursday June 12, 2003 @10:23PM (#6187605) Homepage
    Open spectrum advocates can gain a lot of credibility by demonstrating techniques like SDR, cognitive radio, and mesh networking in the existing unlicensed bands. (The article mentions LocustWorld, which is a commendable example.) Once there's quantitative information on the benefit of the technology it will be appropriate to ask the FCC to reconsider the current spectrum policy.
    • That seems like what is going on with UWB. They allowed limited use in the 3.1GHz to 10GHz range. Article goes on to say if it proves succesful they expect the range to be increased(lowered below 3.1GHz). Seems reasonable. I don't have a handy graph of the spectrum allocations, but most media-money-making spectrum is below 3.1GHz, so testing above that is a safer bet.

      UWB looks pretty interesting, especially if it is opened to the full spectrum. I think even Intel is playing along. It is rather short
    • The funny thing about 802.11b is that it's not spread spectrum in any sense of the word I'm familiar with. It's not resistant to interference, it's not compatible with other transmitters on the same band, and it certainly doesn't appear as "background" to another device. Witness 802.11b versus X10 video cameras. If these were truly spread spectrum, they'd never even notice each other except for a bump in the noise floor.

      Read the article Resisting 802.11 zealotry [ivy.net] and tell me what you think.. This raises a l

  • Intelligent radios? (Score:1, Funny)

    by Anonymous Coward
    Lemme tell you something: As long as companies like Clear Channel rules the airwaves, radio will NEVER be intelligent.
  • and easier to make highspeed internet free could be with WI-FI. at least in urban areas. they could just start constructing buildings with this on there. this really wouldnt work in rural areas though.
  • of Dr. Kolodzy [bldrdoc.gov], it would seem that the FCC were actually quite serious about getting good ideas for dealing with the spectrum shortage.
    You don't use someone with a background at MIT and Lockheed Martin to give you a stack of paper with words on it.

    • Yeah, you get a chemical engineer who's never done anything out of the defense sector (i.e., never had to meet the needs of the commercial market).

      For me to take the open spectrum concept seriously I'd have to hear the people that have designed communication products and networks (and therefore have demonstrated that they understand the problems with existing systems) espouse it. Having non-specialists declare that the status quo is all wrong, and that they have a much better way, is one of the hallmarks
      • No: saying someone is wrong just because he doesn't have a background in that area without countering the claims or showing that the premise is incorrect is pseudoscience. Real science is talking about the actual claims, not about the person making them.
        • No: saying someone is wrong just because he doesn't have a background in that area without countering the claims or showing that the premise is incorrect is pseudoscience. Real science is talking about the actual claims, not about the person making them.

          To some degree I agree with you, however, the Open Spectrum crowd is lead primarily by computer scientists who as far I can tell have ignored some of the issues that crop up when designing radio real radio systems, especially when it comes to receivers.

          • I agree, and thank you for your support. My position is stated in this comment [slashdot.org].

          • Now that's real science :P Thanks for posting that; it's an interesting and informative read.

            On a side note, do you know of any good document or online resource for someone interested in antenna theory (specifically energy decrease over distance and measurement of that decrease), who has had his highschool physics, but isn't getting any electromagnetic theory in his mechanical engineering study?
            I ask because, well, I have 'plans', and you seem quite knowledgeable in this area.

            • At the high school physics level (i.e., no calculus), the first thing that comes to mind is the ARRL antenna book [arrl.org]. It has a good chapter on theory, and another one on measurement techniques. A book more narrowly focussed on HF antennas is Carr's Practical Antenna Handbook [amazon.com], but it lacks the breadth of the ARRL book. A book devoted to the antennas and propagation common to handheld, portable products (including indoor propagation and measurement of the effects of the human body on radiation patterns) is Ra [amazon.com]

              • Thanks a bundle! Especially for Siwiak and Makarov's books; indoor propagation and attenuation and Matlab simulation are /exactly/ what I'm looking for.

                Now all I hope is that I can get 'round the interference caused by monitors, speakers and mobile phones to get accurate enough readings. 3d positional data, here I come :)
  • Of course, the 'last mile' of this plan is quite a difficult hurdle too - an area of the radio spectrum isn't free until the relevant authorities in an area say so. I am willing to bet that they won't say so until there is negligible use of the band by the 'old' use, either.

    This is a sign of a step towards greater availability, but still a long way off. Good show though, and I hope it makes its way there sooner or later. Unfortunately widespread adoption of new radio technology (such as DAB) always seems t
  • People keep talking about how we need more and more: 'more connectivity', 'more bandwidth'.... But there's a reason why broadband is not happening as quickly as some would like: people don't need it.

    First of all, there is a difference between 'needing' and 'finding it useful once you have it'. I don't think anyone really needs the Internet, or only very few. Just look at what is actually flowing around there: adverts, lame entertainment etc etc. High quality information is not what takes up the capacity ou

  • *sigh* Not again ... (Score:4, Informative)

    by dtmos ( 447842 ) on Friday June 13, 2003 @07:01AM (#6189405)

    The open spectrum concept raises its ugly head again. I suppose I shouldn't be surprised; it combines the sexiest of terms (Moore's Law! Metcalfe's Law! SDR! UWB! Spread Spectrum! Mesh Networks! Open Source!) in one neat package, tied with a bow. If only they could work in the magnetic bracelet that cures arthritis, it would be a marketer's dream.

    There are other reasons for spectrum allocation besides the "technology limitations" cited in the ACM article. Two of the most significant are:

    1. The spectrum is used for many different services, with differing Quality of Service (QoS) requirements. Some of these, like the Instrument Landing Systems at airports, emergency services, GPS, etc. I'd like to have dedicated spectrum available solely to them 24x7; the idea that a trapped fireman's call on his handheld 2-way radio is not heard because of interference from a nearby mesh network providing video packets of a football game (or, if you like, the trapped fireman's call on his limited-range Open Spectrum radio is not heard because the burning building's network is already down) is not very appealing.

    Other services, like industrial heating (and even microwave ovens) do not even use the RF spectrum for communication at all; if not limited in spectrum these large transmitted power services can render people incommunicado over large physical areas. Open Spectrum advocates will claim that this last problem will be overcome by the processing gain of the Open Spectrum radio itself; I merely note that increasing processing gain is increasingly expensive, and getting 60 dB of processing gain is a severe pain at wideband bit rates, while it is a trivial exercise for a tuned circuit if the spectrum is allocated properly.

    2. The spectrum has different physical properties that make certain frequencies (and frequency bands) more suitable for certain services. Services that require ionospheric refraction need to operate below 30 MHz; systems using satellite-earth links must operate above 30 MHz. Systems requiring a lot of antenna gain, such as space probes and terrestrial point-to-point links, need to be a high frequency (multiple GHz), where high gain can be achieved in a small physical size by the use of parabolic antennas. Systems requiring worldwide underwater coverage must be below 100 Hz. There are atmospheric attenuation peaks at 24 and 60 GHz (and others higher) caused by oxygen absorption that make these frequencies useless for any trans-atmospheric links, but ideal for short-range unlicensed systems (that's why there are ISM unlicensed bands there). Rain (a.k.a. hydrometeors) becomes a significant attenuator above 5-20 GHz, depending on the rate at which it falls; this affects systems in tropical regions more than those in more temperate areas (see a graph [doc.gov] of atmospheric attenuation). The hydrogen line (1420.40575 MHz), used by astronomers, is a fixed frequency. Etc.--this is just a partial list. All frequencies are not created equal.

    However, if you'd like to stick to technical problems, consider the multiple access problem for these systems.

    The success of 802.11b is often cited as an example for the Open Spectrum initiative--an unlicensed band being used productively. However, 11b has now become the 800-lb. gorilla in the 2.4 GHz ISM band; other services attempting to use that band must coexist with it, but it doesn't have to coexist with them. Any interference it causes to these new services must be borne by them; as a result, we have created a de facto allocated band.

    • Nicely said. As a licensed user of both 900 MHz and 2.4 GHz (Amateur Radio), I find the infringement of multitudes of unlicensed services and the resulting increase in daily interference to be distasteful.

      I could complain until I'm blue in the face to the people with the authority to enforce the rules (unlicensed users MUST NOT CAUSE UNDUE INTERFERENCE to licensed users of the spectrum) but the flood of unlicensed transmitters would simply drown me out in the noise.

      This is not proper bandwidth allocation

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