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World's Longest Wi-Fi Connection 129

Posted by timothy
from the that's-a-long-long-way dept.
axonis writes "The Swedish Space Corporation (SSC) announced today that they have transmitted information via a broadband wireless link over a distance of 310km. They believe that this is the longest distance achieved using wireless connectivity. Alvarion (BreezeCom) is also the original consultant to Ericsson for BlueTooth technology"
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World's Longest Wi-Fi Connection

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  • by martyn s (444964) on Tuesday January 14, 2003 @05:51AM (#5079524)
    kinda knocks the pants off this 1 km wireless connection [slashdot.org]
  • Developing Countries (Score:3, Informative)

    by locarecords.com (601843) <david@locarec[ ]s.com ['ord' in gap]> on Tuesday January 14, 2003 @05:52AM (#5079527) Homepage Journal
    This technology could be a massive boon to poor developing countries in trying to provide technology services and the Internet around their countries. Combined with the cheap 'n dirty homemade wireless links this technology has a *lot* of potential for cheap (or free) Internet access...

    • by Graelin (309958) on Tuesday January 14, 2003 @06:10AM (#5079574)
      I can never understand this stuff. You want to give "poor developing countries" internet access? Don't you think we should spend more time actually developing these places before we start laying in the luxuries? (Remember, the Internet is not some god given right, it's a Luxury.)

      Yeah, let's build a community center in BFE for a group of people who don't have running water or electricity in their homes and the nearest hospitol is a 300M charter plane trip away.

      Yeah yeah, mod me down. Before you do, realize that they're places in northern Alaska that fit this description nicely - and they have a nicer net connection than a lot of people I know.
      • This technology could be a massive boon to poor developing countries
        I can never understand this stuff. You want to give "poor developing countries" internet access?

        I can never understand why the "We could use wireless for poor countries!"/"The money could be better spent" debate has to be posted on every damn wireless communication article.

      • by limekiller4 (451497) on Tuesday January 14, 2003 @07:09AM (#5079716) Homepage
        Graelin writes:
        I can never understand this stuff. You want to give "poor developing countries" internet access? Don't you think we should spend more time actually developing these places before we start laying in the luxuries? (Remember, the Internet is not some god given right, it's a Luxury.)

        In the same way that an article of clothing can either be considered a luxury (eg; furs coats) or a necessity (eg; longjohns in Fairbanks), internet access can be viewed as either a luxury (eg; a good game of UT2003) or a necessity (access to the largest single repository of mankind's knowledge).

        Aside from the jokes that will stem from that last bombastic statement, just because we use it for primarily entertainment purposes does not mean that's all there is to be had. Internet access means not only the ability to communicate and share ideas (linux comes to mind) but also makes political oppression much, much harder to pull off. If you're a wannabe dictator, you want your citizenry stupid, quiet and weaponless.
      • by cioxx (456323)
        I can never understand this stuff. You want to give "poor developing countries" internet access?


        Nice troll. I'll bite anyways.

        Do you use linux? BSD? PHP? {insert technology name here}

        Well guess what? There are features in each and every technology you use daily which were partly developed and enhanced in places where the unemployment is extremely high, the economy is in the shithole, and average person makes $20/month. That doesn't mean poor/developing/third world countries cannot produce geniuses who might contribute something revolutionary to our existing technology in one way or another. Right? Wrong.

        By your idiotic analogy, we should cut off the internet pipes in India. Afterall, majority of India's population lives below the poverty line and doesn't have basic necessities.

        Internet is the artery which feeds innovation. It puts the world at your fingertips and expedites the process of gathering mass amount of targetted, specialized information in matter of seconds. (For the sake of arguement) I might be posting this from the Amazon Jungle. In a way, I am making a contribution to this discussion. I am making my voice heard. Internet is Freedom. Why do you think so many people are worried about the restrictions China is putting on the general populace in regards to the filtering of "objectionable content"?

        Take a moment and think about that one kid out there in the thrird world country hell, who might have became the next linus torvalds, bill gates, et al. But instead, he has to work 18 hours a day in a field to feed himself and will eventually void his potential, just because a greasy fuck like yourself decided he was priveleged more because you had running water and air conditioning, thus making you somewhat more relevant.

        Don't you think we should spend more time actually developing these places before we start laying in the luxuries? (Remember, the Internet is not some god given right, it's a Luxury.)


        Internet is a luxury? Did I miss the memo on this?

        Again going back to my comment about the Great Firewall of China. Why do you think internet makes their heads of state of nervous? I'll give you a clue. It rhymes with INFORMATION. More information you have, more educated you are; the more educated you are, more chances you have to take a stand against bullshit religious fanatics, tyranny, government lies and all that other madness.

        Internet is a vast, unregulated library. Do you want to deny those people of it? Because that's what you're saying. It's not like we're setting them up with internet access so they could solely deploy Counter-Strike servers and amuse themselves.

        Next time think before bringing up such a stupid arguments. Fucktard.
      • by barnaclebarnes (85340) on Tuesday January 14, 2003 @07:41AM (#5079798) Homepage
        and he can eat for a day. Give a man a fishing rod and they can eat for life....or something like that.

        So imagine having a wireless link to a hospital that is 300 miles away. The local semi trained nurse could hook up to the hospital (or another one in another country) with a camera and get expert advice on how to treat a patient without the need to fly 300 miles to the hospital. The money saved on the flight could then be used to supply yet another village with better medical supplies and training.

        Giving local people access to resources about building wells and wind turbines and there maintance could empower the people to help themselves instead of been given handouts. Information on better faming techniques...The list goes on.

        By itself Internet access will not help but combined with an other things it becomes another tool to help.

      • While in many ways I agree, water, electricity, healthcare etc are more important priorities, once you've got these, you need to move onto infrastructure. What better infrastructure to than extremely cheap internet access. This can be used for communication, learning etc. The internet is tool which can be used for the dissemination of information, not just playing UT2003 and downloading mp3's. What better way to help rapidly improve a country and it's populace than give them a tool which they themselves can use for self-improvement, in whatever way they want, not in a way which is dictated by others.
      • by GoRK (10018)
        Actually, I have met a fellow from Nairobi who does wireless installs all over the place down in rural Africa. The people may live in mud huts, but they don't have to move into high-rise low income housing to understand the importance of telecommunications or the Internet.

        According to the fellow I met, one of the biggest problems with laying in any sort of wired infrastructure for electricity, telephone, or data networks into rural places is that the people will dig up the wires for the copper inside of them (or dig up and destroy the fiber thinking it has copper in it.) -- Yet they want to have the phone and the comupter in their village -- go figure. Wireless and solar have been much less expensive for bringing telephone and Internet communications to small villages. The people use them all the time.

        The reason people do this is probably because there aren't significant economic resources to develop much other than education and communications programs in the majority of Africa. If you'd like to find some people/governments/whatever that will build, plumb, electrify, etc. hundreds of millions of houses for these people who we've got to "civilize," then go ahead and do it: you'd probably get some sort of Nobel. Just don't forget the countless billions you'll have to spend building all those schools and hospitals and mini-malls to give the newfound suburbanites something to do and somewhere to work!
      • You want to give "poor developing countries" internet access? Don't you think we should spend more time actually developing these places before we start laying in the luxuries? ... Yeah, let's build a community center in BFE for a group of people who don't have running water

        Why not? Then they can buy water on eBay!
      • The internet is the embodiment of a humans' right to information and communication. It IS important. and it is infrastructure.

    • by EvilTwinSkippy (112490) <yoda&etoyoc,com> on Tuesday January 14, 2003 @06:15AM (#5079587) Homepage Journal
      Not to completely rag on you man, but people in developing countries would have to learn how to read before the internet would be much use to them.
      • Functional literacy in the urbanised areas of some developing countries is close to that in America, which is why typesetting and, increasingly, programming, is often outsourced to places like India. If you can get even low bandwidth Internet access working in rural areas, you have the potential to keep young people in their villages rather than in shanty towns, by providing them with a source of income.


      • I would point out to you that Lee Felsenstein's project (reported on here at Slashdot recently) indicated that the teenagers in the villages involved were "100% literate".

        These assumptions being made on Slashdot that everyone outside the US is illerate is mind-boggling. The literacy rate in the US is such that a significant percentage of high school grads cannot read signs or find Canada on a map...

        Wake up! The educational establishment in the US has dumbed this country down to BELOW third-world levels, IMO.

        Morons...

      • As always in these discussion groups, you learn a lot by being mistaken.

        That said, there are still many issues that concern your average denizen of the third world. Internet access does not exactly rank up there with food and running water (no matter how important we yankee scum may think it is.)

    • by metlin (258108) on Tuesday January 14, 2003 @06:17AM (#5079590) Journal
      More than that, this does away with the need of intermediate hardware for long distances.

      A big boon for use in desolate and (naturally)unfriendly environs.

      Very cool indeed. That is infact something that would be immensely useful in places like this [antdiv.gov.au] for these people [unh.edu].
    • by hcdejong (561314)

      This technology may be cheaper than laying 300 km of cable, but it isn't exactly free. The receiving end used a 2.4 m dish with a tracking system, and I expect the receiver was of a rather higher grade than the one in an 802.11 card as well.

      Basically, all they have done is show that 802.11 (I assume) communication via satellites (balloons, high-altitude UAVs, whatever) is feasible. Other than the protocol used, that's no big deal.

      • As other people have pointed, it has the advantage over cabling that people won't dig it up and try to steal the copper. (it might not have copper, but they don't know that)
    • Combined with the cheap 'n dirty homemade wireless links this technology has a *lot* of potential for cheap (or free) Internet access...



      I'm not sure what you meant by that statement ... whether or not you're talking about providing this service to the less fortunate at a CHEAP cost ... or if you're talking about stealing it for yourself (which would be free).


      In either case, this isn't cheap or free!! Everyone keeps forgetting that the bandwidth that is connected to the base unit has to be PAID FOR (unless you're stealing it, in which case this post will become more of a flame than a reality check).


      Countries, such as the ones you are suggesting, need food, clothing, ... housing .... electric ... other necessities of life ... a computer .... and the infrastructure to support Internet access BEFORE the world would provide them with WiFi. It is a nice thought ... but lets get real here people!!!!


  • by Anonymous Coward on Tuesday January 14, 2003 @05:56AM (#5079538)
    Procter and Gamble has announced a giant pringles can intended for a super bowl promotion has been stolen.
  • no thruput info (Score:2, Interesting)

    by opencity (582224)
    Kilobytes per second?
    'Broadband' implies a certain connection speed(?)
  • Swedes are cheaters (Score:1, Interesting)

    by Albinoman (584294)
    In the US we're only allowed to have a 1 watt antenna. This antenna is a 6 watt antenna.
    • by tigress (48157) <rot13.fcnzgenc03@8in.net> on Tuesday January 14, 2003 @06:10AM (#5079575)
      Actually, in Sweden, you're limited to 100 milliwatts on the 2.4GHz band, unless you have a special permit.
    • Re:Power 101 (Score:4, Informative)

      by EmagGeek (574360) <<gterich> <at> <aol.com>> on Tuesday January 14, 2003 @07:11AM (#5079718) Journal
      This isn't true. The limit is based on your Effective Isotropic Radiated Power, or EIRP. This is formulated by the combination of your output amplifier and your antenna. To get your EIRP, simply add the output power of your amplifier, expressed in dBm (dB referred to 1 milliwatt), to the gain of your antenna, expressed in dB.

      So, if you have a transmitter with an output power of +14dBm, and an antenna with a gain of 18dB, then you have an EIRP of 14+18 = 32dBm, which is almost 2 watts.

      If you have a transmitter with an output power of 14dBm, an amplifier with a gain of +10dB, and an antenna with a gain of +15dB, then you end up with an EIRP of 14+10+15 = 39dBm. So, in extremely simplified terms, you simply add up all the dB's to get your EIRP.

      To convert your EIRP into a "wattage" number, you divide your dBm by 10, and then raise 10 to that number. So, if you have 36dBm, you would do 10**3.6, which is 3.981 Watts.

      Some useful things to remember is that adding 10dB is the same as multiplying the output power by a factor of 10. Adding 3dB is the same as doubling your output power. Likewise, subtracting 3dB is halving and subtracting 10dB is decimating.

      There are two limits, one for point to multipoint and the other for point to point links. For the former, you're allowed up to 36dBm EIRP, which is to say, 36dB over 1 milliwatt, which is 4 Watts EIRP. For the latter, you're allowed 48dBm, which is just a tiny bit over 50 Watts (50.118).

      • Uhm, hate to rain on your parade, but you're off by three orders of magnitude.

        10**3.6 is 3 THOUSAND 981.

        Which leads me to belive that if you have a 36dBm radiated power, you can either cook things with your laptop at a distance of 10m, or your math stinks.
        • 36dBm is most definitely 3.981 Watts. If you had read my post in its entirety, you would have known that a dBm is a dB referred to a MILLIWATT. 10 ** 3.6 is 3981, so 36dBm is 3981 MILLIWATTS, or 3.981 Watts.

          Here's a helpful table for you, in case you need math help in the future:

          -30dBm = 1 Microwatt
          -20dBm = 10 Microwatts
          -10dBm = 100 Microwatts, or 0.1 Milliwatt
          +0dBm = 1 Milliwatt
          +3dBm = ~2 Milliwatts
          +6dBm = ~4 Milliwatts
          +10dBm = 10 Milliwatts
          +20dBm = 100 Milliwatts
          +30dBm = 1 Watt, or 1000 Milliwatts
          +33dBm = ~2 Watt, or ~2000 Milliwatts
          +36dBm = ~4 Watt, or ~4000 Milliwatts

          Hope this helps...
    • exactly. I've heard rumors of GCI (www.gci.net) bouncing a wireless signal (not 802.11 mind you) off denali mountain (highest in N america) in alaska between anchorage and fairbanks... 350 miles apart. If I had a 10 watt transmitter and broke all sorts of fcc rules (maximum gain, maximum eirp, etc) by about a factor of 10, yes i too could set up a 350 mile link that would blow the pants off what the swedes did. But guess what? I don't have thousands of $$$ to blow on a 10 watt amp, 6 foot dishes, tower lease etc etc just to get a 5 megabit connection between myself fairbanks and my friend in anchorage, let alone the money for a lawyer when the fcc gives me hassle.
  • simplified it's digital radio, isn't it? some did radio transmission up to the bounds of our solarsystem...
    • There's a slight difference in using VLF or ELF signals to communicate with a purpose built multi-million dollar equipment, using huge, ultra-sensitive directional antennas, and communicating via the 2.4GHz band, using more or less standard equipment that's available at most computer stores.

      Today's assignment, find out the differences in transmitting a 15Hz ELF signal through, let's say, 100km of air (sea level pressure), as opposed to transmitting a 2.4GHz signal through the same medium. Be prepared to present your findings to the class.
      • Ah, but they didn't use "more or less standard equipment". They used "huge, ultra-sensitive directional antennas", at least on the receiving side (and 2.4 m is huge, compared to what's available at most computer stores).
    • let's not forget that there is a lot more interference on earth. everything from wifi cards, cordless phone, cell phones and microwave ovens. also the deep space network could probably pick up a wifi connection from mars (if wifi was built to communicate with a 20 minute delay).
  • by Mac Degger (576336) on Tuesday January 14, 2003 @06:06AM (#5079563) Journal
    ...but you have to keep in mind that Bluetooth and WiFi were developed for entirely different purposes; Bluetooth was never intended as a wireless computer networking method, just as cable replacement (as in your gfx card to your monitor, your mainboard to your printer, your scanner to your printer).
    • The article doesn't state is was a bluetooth connection. 802.11b uses the same frequnecy. My bet would be they used this to get this far.
    • ...but you have to keep in mind that Bluetooth and WiFi were developed for entirely different purposes; Bluetooth was never intended as a wireless computer networking method, just as cable replacement (as in your gfx card to your monitor, your mainboard to your printer, your scanner to your printer).

      What? Since when could you connect your monitor to your pc with bluetooth. I always thought of it as a little more like wireless USB.

    • FYI: at 1600x1200 resolution, the data rate to your screen is something on the order of 3Gb/sec. I don't think bluetooth was ever designed to do that.

      Fact is, bluetooth doesn't do *anything* all that useful, which is why it still hasn't been adopted five years after the consortium announced that $5 wireless was "coming soon".

      802.11 is where it's at. Good throughput, moderate range. For short range there's either IR (fast, line of sight - PDA sync, printer, etc) or 433MHz AM (slow but goes through stuff - KB/Mouse). Bluetooth is way more expensive than either, and doesn't really solve the problem any better. Also don't forget you still need power for these devices - mayb KB/mouse could be battery powered, but what about CDROM, scanner, etc? That't why USB (for short range) and 802.11 (for moderate range) will rule. Bluetooth will fail.
  • by Seehund (86897) on Tuesday January 14, 2003 @06:08AM (#5079571) Homepage Journal
    Whoa! An improvement of 31000% in 7 hours and 28 minutes [slashdot.org]. ;)
    • 31000% in 7 hours and 28 minutes

      Lets see, Log(310)/(7 hours 28 minutes) = range doubles every 54.185 minutes.

      Radius of the universe is about 1.455 x 10^23 km. Log2(1.5 x 10^23) = 76.945.

      That means slashdot will have an article announcing WiFi range has exceeded the radius of the universe 2 days 21 hours and 29 minutes after this post, [slashdot.org] which would put it at Thursday January 13, @07:50PM.

      -
  • 6 Watts!? (Score:3, Interesting)

    by Raul654 (453029) on Tuesday January 14, 2003 @06:14AM (#5079584) Homepage
    Is it me, or is that just a TAD low? I mean, it seems perfectly logical to me that increasing signal power decreases signal loss and would therefore increase throughput. So why are they using something so weak, particularly over such a long distance?
    • Re:6 Watts!? (Score:2, Informative)

      by MarkTina (611072)
      I guess they didn't want to effect anyone else who might be in the covered area. People get narky when their equipment gets interference.

      Regards

      Mark
    • Re:6 Watts!? (Score:2, Insightful)

      by Drakin (415182)
      maybe that was all that they managed to get a licence for?
    • That is the miracle of high gain antennas. Satellite signals from space aren't all that balsy either. With the right antenna you focus the signal on a single point. Just like taking a magnifying glass and focusing the energy on an ant.

      I'm curious about how they managed to compensate for the curvature of the earth. After a white the signal will start bouncing off the ground en route to the recieving station.

    • Re:6 Watts!? (Score:4, Informative)

      by klaasvakie (608359) on Tuesday January 14, 2003 @06:31AM (#5079630)
      The moment you transmit high watts wirelessly it becomes potentially dangerous. I don't know on what frequencies the above link operates,but if it is 1-2GHz then it could probably be used as a (slow/small/low power) microwave oven if you would push the watts to say 500W or above. The FCC will prohibit you from transmitting signals with energy more than a few watts. For a comparison, the radio transmitter on the Pathfinder mars probe was 4 watts. amazing eh?
      • Yep. This is a big problem with radar installations (which can radiate in the megawatt range at these frequencies). For safety reasons, you want a no-access zone around the radar, but e.g. on naval ships, you don't have room for that. So they set the radar not to transmit in certain directions (e.g. the bridge).

        There are stories about radars being used to de-ice parking lots etc., but I haven't been able to verify them.

      • If they were using some sort of beam antenna, the 6 watts would be concentrated and have an ERP (effective radiated power) of much, much higher, maybe 100's of watts - (for a similar reason to why Laser pointers, at only a few milliwatts, can appear brighter than sunlight) -

        I'm pritty sure that anyone infront of this beam would know about it quickly (as in finding they are unable to see anymore)!

        Tony

    • Consider the watts used to communicate with some of the first orbiting capsules and moon modules...try 15 watts.

      It's the singer, not the song...or in this case, the antenna efficiency.
  • by Anonymous Coward on Tuesday January 14, 2003 @06:14AM (#5079586)
    World's Longest Wi-Fi Connection Made by The Swedish Space Corporation Wireless broadband connectivity achieved over 310km using equipment from Alvarion The Swedish Space Corporation (SSC) announced today that they have transmitted information via a broadband wireless link over a distance of 310km. They believe that this is the longest distance achieved using wireless connectivity.

    The link was made between a stratospheric balloon that was launched from Esrange near the town of Kiruna in northern Sweden and a base station located near Esrange.

    Onboard the balloon was an antenna supplied by Alvarion, the world's most successful provider of broadband wireless products. The antenna was connected to a high-power amplifier with 6 watts power output, a camera and a server. Data, such as environmental conditions and weather patterns, was collected and the information was sent back to Esrange via an Alvarion base station which measured 2.4 meters with 6 watt power output and automatic tracking of the antenna using GPS technology.

    Information received at the base station was then sent back to Esrange via the internal network. The information between the balloon and the base station was transmitted over the 2.4GHz spectrum (2480 Mhz which the SSC is allowed to use with higher ERP) with a stable signal strength of -68 dBm.

    The round trip ping response at 300Km was 300-500 mSec.

    The weather balloon reached a maxium height of 29.7 km and drifted steadily. It finally touched down east of Sodankylä in the northern part of Finland, having travelled approximately 315 Km.

    Lars-Olov Jonsson, System engineer RF and microwave, at SSC Esrange commented: "This is an amazing technical achievement, the difficulty of which should not be underestimated. Alvarion has developed extremely robust equipment capable of operating in a very harsh environment. Its technology has helped us save money, time and energy."

    Zvi Slonimsky, CEO of Alvarion, said: "Time and time again, wireless is proving to be a genuine option in the broadband arena for enterprises, incumbent and alternative operators looking for alternatives to fibre and satellite to be continued."

    About the Swedish Space Corporation
    The Swedish Space Corporation is a state-owned, commercial company with about 300 employees at its locations in Solna (near Stockholm) and Kiruna. SSC operates the Esrange facility outside Kiruna for rocket and balloon launches for scientists from the whole world. SSC also operates one of the world's busiest satellite ground stations at Esrange, supporting a growing number of satellites. In Solna, SSC develops state-of-the-art satellites, space vehicle subsystems, payloads for rockets as well as airborne systems for maritime surveillance. These products are sold on the international market. Swedish Space Corporation owns fifty percent of Nordic Satellite AB, which distributes television and offers other telecommunication services on its geostationary Sirius satellites.

    About Alvarion
    Alvarion is a premier provider of solutions based on Point-to-Multipoint (PMP) Broadband Wireless Access (BWA) used by telecom carriers, service providers, and enterprises worldwide. Alvarion systems provide Internet access and voice and data services in the last mile, cellular network feeding, building-to-building and wireless local area network (LAN) connectivity.

    Alvarion offers the broadest range of BWA solutions by market segment and frequency band, designed to address all carriers' and service providers' business models. With its combined market experience, strong customer base, diversified distribution channels and field-proven deployments, Alvarion is a leading BWA pure play provider for every end user profile, from residential subscribers to business customers.

    This press release contains forward-looking statements that are subject to risks and uncertainties. Factors that could cause actual results to differ materially from these forward-looking statements include, but are not limited to, general business conditions in the industry, changes in demand for products, the timing and cancellation of orders and other risks detailed from time to time in Alvarion's filing with the Securities and Exchange Commission, including Alvarion's Form F-1.

  • by andbutso (637818) on Tuesday January 14, 2003 @06:29AM (#5079622)
    Now there is just going to be stupid shit like LAN parties out in the middle of the desert.
    Or maybe people think that's cool
  • MW radio? (Score:1, Redundant)

    by peterpi (585134)
    Forgive me if I'm being stupid here; but given that medium wave radio signals easily carry over such distances with enough clarity to enjoy music, why is sending a digital signal such a big deal?

    I doubt the bandwidth would be all that high, but if I can get 33kbit/s down a crappy telephone line then I expect to get a lot more across a nice powerful radio signal.

    • I forgive you, my child. =)

      On the other hand, this is just a few megabits! My server can transmit data at gigabit speeds! What? Different technologies? Different media? Different circumstances? What do you mean? =)

      PS: A radio station is HOW many watts? Your FM Radio is sending HOW much data back?
      • "On the other hand, this is just a few megabits! My server can transmit data at gigabit speeds! What? Different technologies? Different media? Different circumstances? What do you mean? =)"

        That's kind of my point; it's a tradeoff between bandwidth, distance and (inverse of...)cost. If you increase one, the other two go down.

        Whatever distance you can transmit data across, I can do it further (at lower bandwidth for more money). Likewise for high bandwidth and low cost.

  • What about Voyager? (Score:4, Interesting)

    by the grace of R'hllor (530051) on Tuesday January 14, 2003 @06:51AM (#5079682)
    How many millions of kilometers away are the Voyager probes right now?

    It ain't broadband, but data has been sent over their wireless connection.
    • I wonder what the gain is on a Deep Space Network antenna...
      • I wonder what the gain is on a Deep Space Network antenna..

        I'm not a telecom's expert, but i believe that deep space probes retransmit every signal a few hundred times at fixed intervals. This exploits the ability (for lack of a better word) of white noise that it cancels itself when adding all the signals. this technique can allow one to resolve signals even when you have a noise to signal ratio of a few dB. It all depends on how many times you want to retransmit. I am guessing that the gain would not be much more than the antennae used for the link in the article. Remember that high gain will amplify the noise as well...
        And yes I know it's not 10Mbps
  • Useless (Score:2, Funny)

    by trynis (208765)
    "The round trip ping response at 300Km was 300-500 mSec."

    With this kind of lag you can't play CounterStrike.
    • These figures are a bit strange.

      Speed of light is ~300,000km/s; that translates into a ping time of 300/300,000 * 2 = 2ms (there and back) plus protocol overhead, which should be negligable.

      So there's no way that they should have a ping time as high as that; unless their link was down at 300 baud or something- they don't mention the link speed. If they were that low then the packets themselve could take half a second just to send 8-)

    • what kind of a balloon plays cs
  • Sorry, but the people who get internet via a geostationary satellite (36'000 km) break this record daily.
  • by kylegordon (159137) on Tuesday January 14, 2003 @07:16AM (#5079733) Homepage
    This is such a misnomer. It's a bog standard long range data link. 'Wi-fi' has generally become the term to describe 802.11 based networking, and not other types of radio data links Like packet radio working through moonbounce (admittedly, not broadband). The day I need a 2.4m dish connected to my laptop for 'wi-fi' is the day hell freezes over.

    Slashdot talking bollocks?? Never!!!
    • I dont know if this article clarifies it, but the Alvarion equipment used was 802.11 FHSS running at 1 megabit in the 2.4GHz frequencies known as the ISM band here in the US, just like most of their other WLAN stuff. It was not packet radio. They do produce radios in other bands that operate with the exact same technology - ie they would be 802.11 compatible if not for the frequency. The only thing they did that you couldn't do here in the US is use such a high power output on the 2.4 frequencies. (And of course, FCC approval of your amp/antenna system) You could; however, duplicate this sort of work on the 2.5GHz band with Alavarion equipment and an appropriate MMDS license.

      ~GoRK
  • Granted that this is a pretty cool demonstration of the ability to beam 2.4GHz over a l-o-o-o-ng distance while maintaining adequate signal to noise. But a constantly drifting balloon? Seems like tracking this with the ground antenna, which is probably highly directional, would be a total pain. But maybe...
    • They do a lot of research on northern lights up at Esrange, so I imagine this is developed to be able to retrieve loads of info from research equipment without having to bring back the equipment and depending on it has not landed in a stream.

      But I agree that is not a big selling killer application!

    • by peekitty (613568)
      It's super useful! If you need to wirelessly transmit pr0n to a balloon 29km high.
  • I am beginning to suspect that my choice of coca-cola cans as reflectors on the Yagi antennae may be affecting signal quality... Brain: It proved that radio was a powerful tool. And now, Pinky, the advance of technology has brought us an even more powerful tool. Do you know what that is?

    Pinky: Ummm... the rubber band?

  • Some company with "Volvo" in its name has recently admitted its responsibility in the failure of the first launch of the new Ariane 5 rocket.
  • Please longest? (Score:3, Interesting)

    by Neck_of_the_Woods (305788) on Tuesday January 14, 2003 @09:39AM (#5080485) Journal

    If you not going to use a standard you not even close to the longest wireless link. Anyone remember contacting voyager a couple months back. Correct me if I am wrong but they are not running a wire all the way out there are they?

  • by eggboard (315140) on Tuesday January 14, 2003 @10:31AM (#5081021) Homepage
    Wi-Fi is specifically a certified version of 802.11a or 802.11b or both. Not a generic term. It's confusing when used generically.

    What's being discussed here is spread-spectrum frequency hopping or direct sequence -- probably FHSS not DSSS. It should be called by its right name as this is Slashdot, after all!

    With 6 watts of output power, you could send 802.11b quite far as well using off-the-shelf equipment. This achievement is only remarkable because of the components involved (balloons, etc.), not because of the distance.

    Because of the curvature of the earth, you have maximum distances without building huge towers that are only in the tens of miles, even with curving of the 2.4 GHz waves around the globe. The small wavelength means you don't get an enormous bending effect.

    If you beam from the earth straight up, you have longer possible distances.
  • See, here's where the metric system comes in handy! In Europe, this thing went 310 kilometers!!! In America, it would only have gone 192.634 miles.

    Maybe this metric thing isn't so bad...
  • I could have sworn THIS [slashdot.org] was the longest data transmission we'd ever seen.
  • Now the drive-by hackers don't need to leave their own driveway.
  • First a correction:
    This was not a weather balloon, but a stratospheric scientific balloon: these can carry payloads up to 8000lbs (on the extreme upper limit) and can keep them up for weeks (the current record is 31 days)

    Now my question: what was the link they were using? What was the bit rate? What what was the bit loss rate? Were they shipping TCP/IP, or was it special purpose format. If the former, I'm intriged - how nice it would be to log into one's balloon borne stratospheric telescope and fix those lingering bugs (bugs? what bugs? never...)! If the latter... well, at this very moment I am monitoring data from our stratospheric balloon instrument which is currently at -80.5 lat, and -78.2 lon and an altitude of 31.2km (ie, over the antarctic plateau). We're only getting a 6kbit link (through the TDRSS sattelite) now that we are out of line of sight, but -80.5 lat, -78.2 lon is a *long* way from here in Toronto :)

  • I believe Voyager transmitted data wirelessly from several million kilometers. Correct me if I'm wrong, but last I checked several million kilometers is larger than 310 kilometers.
  • by MadFarmAnimalz (460972) on Tuesday January 14, 2003 @12:10PM (#5081820) Homepage

    Wireless networking might just be a multiple violation of the law in Egypt.Details here [cairotimes.com] and here [linux-egypt.org].

  • Of course I'm still waiting for the reply packets...
  • I think DirecPC would qualify as the first and longest... a 22,000 mile uplink to a satellite, followed by a 22,000 mile downlink to a base station. just because your access point's in the sky still makes it wireless, right?

    If two-way is your game, then Starband is probably the first, and tied for the distance...

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