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Wireless Networking Hardware

Airgo Quadruples Wi-Fi Limit 152

Posted by CmdrTaco from the everybody-likes-more dept.
QED writes "Airgo Networks, a privately held maker of wireless networking components, said on Wednesday it has developed chips that will increase the Wi-Fi speed limit by a factor of four. The Palo Alto, California-based company, which designs its chipsets around Multiple Input and Multiple Output (MIMO), a wireless technique that uses different radio channels to improve both speed and transmission quality, said it has achieved data rates up to 240 megabits per second (Mbps)... "
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Airgo Quadruples Wi-Fi Limit More

Airgo Quadruples Wi-Fi Limit

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  • WiFi speed is fine for me... but... (Score:5, Insightful)

    by Anonymous Coward on Thursday September 15, 2005 @11:08AM (#13567220)
    ... I need better distance and fewer signal dropouts. I'm not talking about all that far distances either, just 200-300 feet inside an office building with many sheetrock walls and twisty hallways.
    • The day you get your wireless singal to go through multiple sheetrock walls and corporate radio signal protection is the day your skin starts to boil.

    • ...I'm not talking about all that far distances either, just 200-300 feet inside an office building with many sheetrock walls and twisty hallways.

      Well, MIMO may turn out to be useful in your office. Like what you have described, your office has several walls and twisty hallways. This causes multipath radio signals that degrade the main wireless signal, mainly through of fading and interference. However with MIMO, the reflected signals are put to good use as they are recombined by the MIMO algorithm.

    • Are you kidding? This will be like any other wifi standard. You'll get close to 240Mbps when you're sitting right next to the base station. For every five feet you put between your antenna and the base station, transfer speeds decrease by 75% of the total. The same goes for any obstruction whatsoever that may come between you and the base station, including a atom-thick sheet of gold foil. Wifi blows. I'll stick with wired, thank you very much.

  • Umm...yeah... (Score:4, Insightful)

    by LordPhantom ( 763327 ) on Thursday September 15, 2005 @11:10AM (#13567237)
    So, in other words, they've developed a chipset that will allow a router/WAP + WLAN card to use multiple channels at once...

    Not only is that not -really- upping the bandwidth limit (they just got more signals, not a bigger throughput per signal), it seems to me that it'd blast out 1/3 - 1/2 of the avaialble spectrum within range for wireless.....which means if you buy one and are in an apartment/city/whatever, you could be a real jackass to your neighbors simply by using it...

    • Re:Umm...yeah... (Score:3, Interesting)

      by stinerman ( 812158 )
      If I'm not mistaken that may be against FCC regulations if it interferes with the operation of other people's home equipment.

      I'd be happy if someone could provide more info.

      • Re:Umm...yeah... (Score:3, Interesting)

        by robertchin ( 66419 )
        Actually, it may be against FCC regulations because the 802.11b band sits partially in a ham band. Ham radio is the primary user of the band, and thus home users have to accept any sort of interference created by both other home users and ham radio users. Additionally, if home users cause noticeable interference to a primary user (in this case licensed ham radio operators), the primary user can complain to the FCC, and you could be required by the FCC to discontinue use of your equipment. Only three out of

      • Re:Umm...yeah... (Score:2, Informative)

        by spdt ( 828671 )
        That would be under Title 47, Chapter 1, Part 15, Section 15.5, Subsection B of the US Federal Code.

        http://edocket.access.gpo.gov/cfr_2004/octqtr/47cf r15.5.htm [gpo.gov]
    • "Unfortunately, these accomplish this speed increase by bonding together two or more of the 802.11g standard channels. Therefore, if you have multiple 802.11g networks, they can interfere with each other. This can result in a slowdown in the conventional 802.11g network.

      MIMO avoids this problem by not bonding together 802.11 channels. Instead of sending one data stream down one channel and another stream down another channel, MIMO simultaneously transmits multiple data streams over the same channel.
      "

      From th

    • You're talking about bonding, not MIMO (Score:4, Informative)

      by tessaiga ( 697968 ) on Thursday September 15, 2005 @12:09PM (#13567789)
      You're thinking of just taking different frequency channels and bonding them together. That basically just uses more frequency to transmit more data rate, while the number of bits per second per hertz (the spectral efficiency) remains the same.

      In the MIMO system they're discussing here, you use the same frequency bandwidth but deploy multiple antennas, which gives you spatial diversity. Wireless communications are basically limited by the probability that your channel goes screwy and experiences what's called a fading event, where your signal suddenly drops because of interference. This means you have to be more conservative in the data rate you transmit at.

      What they're trying to do is transmit, receive, and resolve multiple signals in the same frequency band by using multiple antennas, and resolving them in a clever way to try to create independent data channels. Since each antenna is physically at a separate location, the signal paths (and hence the fading characteristics) from the transmitter to the receiver will be more independent. Then the odds that all channels experience fading simultaneously drops significantly, improving the overall robustness of your communication channel to fading. That means you can be less conservative and achieve higher bit rates through your channel.

      In short, same frequency usage, but they're getting spatial diversity by using more antennas and giving themselves a more robust channel.

  • When will the wireless market begin to stabilize? I will not invest in wireless technology that very well may become out of date or unsupported by newer hardware in the near future. As such, I will continue to use gigabit ethernet, thank you very much.

  • 240mb/sec? (Score:4, Insightful)

    by Swamii ( 594522 ) on Thursday September 15, 2005 @11:12AM (#13567258) Homepage
    Wow. Ok, I'm not great on the conversions, but isn't 240 megabits/second = 30 megaBytes per second? If that's really the case, I don't think data can even be written to my hard drive that fast. Wow.

    • Re:240mb/sec? (Score:2, Insightful)

      by Anonymous Coward
      No, but you can easily max it out when there are few computers on the network. I have 8 machines on a 108mbit lan and it is frequently maxed out. 240 would also be maxed out (although less frequently).
    • 30MB/sec. is rather pedestrian, any new IDE drive can do that. My desktop IDE drive (WD Raptor) does 64MB/sec. average. Your boot times and application load times would improve dramatically if you got a faster drive.
    • Depends on your harddrive, but most modern ones are slightly faster (i.e 50-60 MBs). However, it still is pretty darn fast. It is doubtful that what you would be streaming would use up all of that, or that you could practically achieve that (that quote is probably from testing in a faraday cage in vacuum). Plus, not a lot of what you transfer over the network goes to your harddrive. Streaming videos and music, web pages, ect... all just go through your ram then into oblivion. Plus, all that bandwidth i
  • I have to believe this is for corporate use, but if so, I hope the new standard sports heavy security.

    I hope its not marketed towards Joe Sixpack. I'm sure he'll be impressed right up until he realizes that his Cable is only 6Mbps.
    • I'm sure he'll be impressed right up until he realizes that his Cable is only 6Mbps.

      Or less.

    • True, but fast wireless transfers of files between computers in the local subnet is nothing to scoff at!
      • Do you really copy stuff on your local subnet that often? Go get a cup of coffee or something. I mean maybe at work or something but definetely not at the home.
        • At home I use more local bandwidth than at work. At work, its a couple of files here and there. At home, streaming media from the "server" to the garage or pool deck (music), or to the living room (video), sometimes all 3 at once. Add in some remote X and other goodies, and it comes up quick.
        • Well since it is not uncommon for my wife to watch shows upstairs on the bedroom ReplayTV that are stored on the living room ReplayTV, while at the same time I am watching shows in the living room that are stored on the bedroom ReplayTV. Add to that I might be downloading a linux distro to try, and copying TV shows from my ReplayTV server to my laptop to watch while I am away for the weekend.

          Honestly, sometimes the 100Mbs wired network really isn't up to snuff.

  • Real Speeds? (Score:5, Interesting)

    by jolar ( 905312 ) on Thursday September 15, 2005 @11:12AM (#13567260)
    So what are the real speeds? No one gets 54mbps on 802.11g hardware, so I don't expect 240mbps on this MIMO stuff.

    I don't understand the way wireless speeds are rated. I got very close to 100mbps on my LAN before I upgraded to gigabit. I can't get anywhere near 54mbps on my wireless if I put my Powerbook right next to the wireless router!

    • Re:Real Speeds? (Score:3, Informative)

      by CdBee ( 742846 )
      54Mbit/sec = 27 Mbit/sec each way. 20mbit/sec is the max reasonable bandwidth...
    • I've gotten 40 megabit out of 54 megabit across 20 feet of room in my apartment, using a dlink wireless router and the intel 2915 that came with my laptop.
    • I dunno about you but I get 88 megabits per second (11 megabytes per second) from my wired LAN.

      Sure your not confusing megabits and megabytes?

    • Re:Real Speeds? (Score:3, Funny)

      by Eil ( 82413 )

      I can't get anywhere near 54mbps on my wireless if I put my Powerbook right next to the wireless router!

      Because 54mbps is the speed you'd get under ideal circumstances. In order to achieve maximum performance from your wireless equipment, you have to ensure that you eliminate all possible causes of interference including microwaves, telephones, trees, walls, and air. Your best bet to get the maximum wireless speeds possible is to directly connect the powerbook's antenna to the router via a short length of c

      • Re:Real Speeds? (Score:3, Interesting)

        by LarsG ( 31008 )
        Because 54mbps is the speed you'd get under ideal circumstances

        Nope.

        54Mbps is the highest supported signalling rate when transmitting data frames. But unfortunately the 802.11 MAC (CSMA/CA) is braindead. You can't send data frames all the time, so the maximum throughput is a bit lower. Acually quite a bit lower if you use RTS/CTS and 802.11g equipment not in '11g only' mode.

  • Multiple paths, not multiple frequencies? (Score:5, Informative)

    by RradRegor ( 913123 ) <rdarr1@ a d e l p hia.net> on Thursday September 15, 2005 @11:13AM (#13567276) Journal
    I'm not certain, but I think the word channel may be misleading here. I think that MIMO is actually using the same bandwidth, just combining multiple RF paths to enhance the signal to noise ratio. Another MIMO link is here. [networkworld.com]
  • So is this 240mbps bandwidth total as in everyone shares, or is it 240mbps dedicated? -Rick
  • Ehternet seemed to grow by powers of 10, but I don't quite understand how WiFi does it

    10 Megabit, 100Megabit, 1000Megabit
    vs
    11MB to 56 MBs and now this...

    What is being improved on to increase bandwidth? Can someone explain - I'm a software geek, not hardware.
  • The article says : achieved data rates up to 240 megabits per second

    Now either they acheived 240Mbps, or they didn't.

    I will give you a present of up to one billion dollars. Puhlease!

    • Translation (Score:3, Informative)

      by jd ( 1658 )
      "Up to" means that there was a second in which they may have reached 240 megabits per second. I'm not sure if this is the data before or after compression, so 240 bits of 1's run-length encoded might easily be transmitted in one second.

      It is also unclear as to whether the data was actually intact or not, how much error-correction the network card needed to perform, how many resends were required, etc.

      In other words, even a transmitted rate of 240 megabits per second need not equal 240 megabit transfer rates

  • Still not as fast as wired. (Score:5, Informative)

    by Guspaz ( 556486 ) on Thursday September 15, 2005 @11:21AM (#13567348)
    4x the speed is still not that great.

    Current 802.11g devices have a theoretical throughput of 54mbit, and a real-world throughput of actual data of 10 to 20mbit. So it follows that Airgo's new cards will permit 40 to 80 megabits.

    Now, wired 100mbit networks can reach 80mbit real-world speeds (Actual after-overhead bandwidth), so at first glance it looks like we're there. Except we're not.

    The important things to keep in mind is that wireless networks behave like hubs, not switches, and on top of that all data must go through the access point. So if you have two computers close to an AP, you take up 40mbit for computer -> AP, and the other 40mbit for AP -> computer.

    In other words, they claim 240mbit, but the fastest real-world transfer between two wireless devices is probably about 40mbit, IF those computers are very close to the access point. If the computers are a bit further away, you will get 20mbit. 4 computers doing 2 transfers and each transfer goes at 10mbit.

    So you see? 4 computers 50 feet away and you're already down from 240mbit to 10mbit. This is very far away from wired performance.
    • I don't think most people care that much about computer to computer wireless. I think the typical usage model is:

      computer -> wireless AP -> DSL/Cable -> internet

      And all that people really really want is for

      computer -> wireless AP

      to be faster than

      DSL/Cable -> internet

      Computer to computer transfers that require high speeds are mainly restricted to a smaller crowd doing wireless video streaming. There you really only care that:

      computer -> wireless AP -> computer

      is faster than mpeg2/4/div
      • Worse, in a practial sense many people are limited by the amount of interference on the channel, which MIMO makes worse.
      • 802.11g is, in nearly every case, fast enough for simple internet sharing. Very few people have broadband faster than 10mbit, and multiple people using that internet connection are sharing it anyhow, so you're fine. For streaming video, it depends what you are streaming and to how many devices. DVDs are, IIRC, something like 7 or 8 megabits. Assuming there is some distance between the AP and device receiving the stream, you could only really do one stream at a time on an 802.11g network. Unless we're talkin
    • So it follows that Airgo's new cards will permit 40 to 80 megabits

      No it doesn't. The release doesn't specifically say, but in order to achieve the full data rate, a different modulation technique MUST be used. If the modulation is more efficient than 802.11b/g/a, then you're calculations will be erroneous.

      In fact, the release hints at that already as it says it is backwards compatible with 802.11a as well (which seems to hint that multiple frequency spaces are used simultaneously). 802.11a modulation is mor
      • I was under the impression that most of the wasted bandwidth on wireless networks is from collisions and transmission errors. Assuming that efficiency of modulation is also a major factor, would it not stand to reason that when you take 240mbit and then take into account collisions, transmission errors, overhead, and the shared bandwidth nature, you're still going to get a real-world throughput of significantly less than 100mbit?
        • No, the inefficiency comes from the construction of an 802.11b packet. Only a portion of a wireless packet actually contains data. The rest contains WEP information, AP information, MAC information and such.

          If 802.11b says it is capable of 11MB, then you figure the amount of data than can carry is at MOST the percentage of the 802.11b packet that is actually data. Then you figure on the collisions and retransmissions and it goes even lower.
      • different modulation technique MUST be used

        The 802.11 MAC is horribly inefficient. 802.11a and 11g in g-only mode has 30.5Mbps maximum theoretical UDP/IP data throughput. 19.5Mbps for 11g in 11b compatibility mode. Numbers for TCP/IP are lower. And this is before any problems caused by colissions or interference. Way below the signalling rate of 54Mbps.

        A different MAC must be used if we are to see any dramatic benefits of faster modulation rates.
  • First you're going to spam across multiple channels. Yes, that'a real good idea. I can almost hear my cordless phone going static at the thought of that.

    How about we work on getting rid of the distance limitations of Firewire or USB, instead? We've already gotten their speeds up to 400-800 megabits. Why spam across the airwaves when we can spam faster thru copper? (No pun intended)

    Another thought. Oh, 240 megabits, eh? So I can receive your key packets faster for decrpytion? All your wireless bandwidth are
  • The firey horse porn of vengence shall be delivered at approx. five times the speed! Most excellent indeed.
  • Which is what I think this technology is. It simply will not work where I live for example. There are folks on almost every channel (while they should be only on channels 1,6 and 11), and even single-channel wireless gets tricky.

  • The story behind this announcement (Score:5, Informative)

    by RebornData ( 25811 ) on Thursday September 15, 2005 @11:34AM (#13567456)
    Airgo is a participant in one of two consortiums of companies promoting competing technologies to use in the 802.11n standard. Here's an article that covers the situation:

    http://www.reed-electronics.com/electronicnews/art icle/CA445702 [reed-electronics.com]

    Airgo is obviously trying to gain leverage with their technology by getting it out on the market early. I don't think this is a good thing in the long run, since we all have benefitted by the degree of standardization in 802.11b/g and Airgo seems to be trying to get their own proprietary technology out there in front of the legitimate standards process.

    -R
  • this press release (and several other noises will surely follow) is more to combat Intel+Marvel+Broadcom camp which has taken a different position that airgo in the 802.11(n) standards work. these are merely battle lines being drawn for the standards meeting (where demonstration of feasibility etc command premium). now going up against intel (or cisco) in these standard meetings has not met with much success in the past though and it remains to be seen (claims of 240Mbps bw notwithstanding) if Airgo surv
  • There's an article on MIMO [technologyreview.com] in the latest physical issue of Technology Review [technologyreview.com] magazine. Fortunately, the article's on-line.

  • Reliability Speed (Score:3, Interesting)

    by Glog ( 303500 ) on Thursday September 15, 2005 @11:47AM (#13567559)
    I think a lot of people in areas affected by recent disasters (New Orleans, New York, DC, etc) that reliability in EXTREME disaster conditions trumps speed improvements any day of the week. I'll be happy with half the current speed of wi-fi if I could RELY on it to WORK if a disaster were to strike. Of course that has more to do with the signal strength and the actual transmitter network itself.

    • The Dept of Homeland Security is working on radio blimps for this purpose -- basically putting a bunch of cell/data transcievers on a blimp and flying it over a disaster area.

      This would (presumably) solve some of the problems from Sept 2001 in New York, when all the radio gear on top of the WTC went down and the rest couldn't keep up with traffic. It would have been very helpful indeed if they could have got one of these flying over New Orleans, particularly since the lack of communication was the bigges

  • Great (Score:2, Funny)

    by WesLsoN ( 696427 )
    Now someone can ghost my hard drive and pull away before I even see them parked outside

  • Uhhh... (Score:3, Insightful)

    by Sheepdot ( 211478 ) on Thursday September 15, 2005 @11:51AM (#13567593) Journal
    and the distance is... ?

    Yes, I RTFA and didn't see it. I know enough about MIMO to know that it's great, but until we've come up with a way to comfortably blanket the world in a massive wireless network, bandwidth isn't a big deal.

    IMHO, 802.11s is where the funding should be. It is right now for the most part, but more could be spent.

    For more info on the available protocols:
    http://en.wikipedia.org/wiki/IEEE_802.11 [wikipedia.org]

  • Freequency (Score:3, Interesting)

    by Doc Ruby ( 173196 ) on Thursday September 15, 2005 @11:53AM (#13567615) Homepage Journal
    Phased arrays finally approach the market. If these products capture significant profits that are reinvested into R&D for better phased arrays, we might be able to finally escape the "1 frequency : 1 channel" trap we've lived in for a century.

    Phased arrays use spatial info of signal origin/reception to distinguish between different channels, even in the same frequency. Like how our eyes' retinas can distinguish between two red traffic lights in front of our cars, rather than just "seeing red" in the single frequency they share. Conversely, lower power transponders might be able to get the same bandwidth, a boon to mobile devices, or just remote telemetry.

    The implications for info density are vast: multiply bandwidth by multiplying transponders. And the political implications are fundamental: the FCC is built entirely on the need to register frequency use to a single operator, to prevent signal interference. Phased arrays don't require the registry, because only physically coincident transponders could interfere, and that's practically impossible. The FCC won't be necessary to protect from signal interference, and won't be able to abuse its power, for example by regulating cable subscription content.

    Even "WiFi" will be really unleashed. It became popular due to its unusual status in an "unlicensed band", which therefore doesn't require a license for its low power transmissions. The FCC will still be useful in certifying devices, that they don't transmit unhealthy radiation or otherwise pose a physical danger. Phased arrays promise freedom from physical constraints which have produced constraining, mission-creeping bureaucracies. MIMO might be just the beginning of throwing off those shackles for good.
  • I design wireless networks and hardware for a living. I'm running simulations of video streams across ns2 and NCTUns as I write this.

    Yes, you can increase throughput. Yes, you can cross-correlate FEC across channels to reduce errors. However, this solution hogs the spectrum, isn't tileable to create large wireless networks because of its inefficient use of channels (not to mention that the algorithm they're probably using only works because 802.11 has fairness problems, will definitely conflict with 802.
    • (In full disclosure I did some work with Airgo in 2001 and early 2002, and earned some stock options as a result of that work. Having said that, I haven't had any insider access since that time, which was well, well before they were shipping any product. In fact, I'm so out of the loop that this announcement came as a complete surprise to me, as did their previous announcements that companies were shipping products using their chips.)

      I design wireless networks and hardware for a living.

      Which makes your lac
      • Ah, cool. Someone that actually knows how this works.

        Do you happen to know what kind of real world performance we might see from this equipment, given the inefficiencies required to play nicely with existing 802.11 gear? I seem to recall that RTS/CTS or CTS-self would be required, which would cut down quite a bit of available air time.

        Also, do you know of any plans to ditch or improve the 802.11 MAC? .11a 54Mbps signalling gets somewhere around 60% effective throughput, and if I remember correctly that perc
        • Alas, because I finished my work there in early '02 (and even then only as a part-time consultant), and because my work was limited to the PHY layer, not the MAC, there's a lot I really don't know. I have since not been involved in 802.11 in any capacity.

          However, 802.11-pren stuff really does play nice with existing 802.11b/g gear. It doesn't hijack the packet timing or anything like that. It was designed that way from the start; admittedly at a cost of performance, but they seem to be making it up in other
        • Do you happen to know what kind of real world performance we might see from this equipment, given the inefficiencies required to play nicely with existing 802.11 gear?

          Airgo says 100 Mbps, so maybe 80 Mbps to be safe.

          Also, do you know of any plans to ditch or improve the 802.11 MAC?

          802.11n is overhauling the MAC.
  • "Current Wi-Fi technology tops out at 54 Mbps. Remarkably, Airgo's technology also beats wired home-networking technology, which generally reaches only as high as 100 Mbps"

    Airgo's technology doesn't beat wired home-networking technology; Airgo's tech isn't even deployed. Instead, Airgo's tech is faster than the average home network.

    Assuming the specs given are correct, this will likely result in lowered prices on 1Gbps wired network utility, as people will be choosing to upgrade to Airgo's MIMO or to
  • If MIMO technology uses the fact that radio waves bounce around and can reach the reciever through multiple paths, and thus reconstructs the signal much more accurately, wouldnt it be possible to determine location by the variations in the multiple paths? And thus, a reciever could know which signals are meant only for it? Depending on how close they are and how accurate this stuff is, it could get around the shared bandwidth problem of wireless (not to mention avoiding colisions).

    You could also work this

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