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Airgo Quadruples Wi-Fi Limit
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)... "
... 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.
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...
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 I will not invest in wireless technology that very well may become out of date or unsupported by newer hardware in the near future.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.
Cyric Zndovzny at your service.
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.
Tech, life, family, faith: Give me a visit
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!
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.
Good point, but for some of us there would be a big benefit with higher wireless speeds. My cable modem has a typical download speed of 3Mbps so even the 11Mbps (max) speed of 802.11b isn't being used to its full capacity. But I often need to move large files between my laptop and my PC. If I don't want to wait 10 minutes or more for a file transfer I have to carry my laptop into my home office, plug it into my Ethernet switch and transfer the files there. With faster Wi-Fi I could avoid this minor hassle.
Quantum mechanics: the dreams that stuff is made of.
That a great way to be a good neighbor. Piss all over all the channels available so no one else can do anything.
I was about to post with the same sentiment until I read more on the tech.
MIMO is not your typical blast-it-on-multiple channels approach. This article discusses the technology. Instead of using up a bunch of channels, MIMO systems send multiple signals on one channel and use multiple antennas and advanced algorithms on both ends to sort out which signal came from or went which direction.
Two wrongs don't make a right, but three lefts do.
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.
To put this in software terms, They are multithreading the connection.
-Rick
"Most people in the U.S. wouldn't know they live in a tyrannical state if it walked up and grabbed their junk." - MyFirs
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:
t icle/CA445702
http://www.reed-electronics.com/electronicnews/ar
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
You might as well have said :
"When will the technology market begin to stabilize? I will not invest in technology that very well may become out of date or unsupported by newer technology in the near future. As such, I will continue to use an abacus, thank you very much."
All movements for social change begin as missions, evolve into businesses, and end up as rackets.
There's an article on MIMO in the latest physical issue of Technology Review magazine. Fortunately, the article's on-line.
no pun existed.
useless sig advice - Read Nabokov.
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.
Now someone can ghost my hard drive and pull away before I even see them parked outside
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
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.
--
make install -not war
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.
The bold print giveth, and the fine print taketh away
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. There are plenty of ways to fudge the numbers.
A trivial example: A network card operates at 240 megabits per second, but needs 240 retries to get enough data across for a genetic algorithm to build the most probable originating packet that could produce the data received, where the genetic algorithm adds several minutes to the transmission time of a single packet. At what speed does the card operate?
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
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.
w00t
Yes, it's using different channels, but not in the sense you and I typically think of it, as chunks of spectrum. Rather, it is exploiting multipath, where each path is treated as a separate channel. Multipath is usually a significant problem for traditional wireless communication, because it causes dropouts and frequency nulls and such. But it turns out that if you're clever (and these guys are) you can exploit multipath to shove more data down the same sized pipe.
So in short, they're not hogging spectrum to get these speeds; they are being good neighbors.
(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 lack of knowledge about this stuff a little more disappointing.
not to mention that the algorithm they're probably using only works because 802.11 has fairness problems, will definitely conflict with 802.11n (which also uses MIMO), and has a kook for a CEO.
The cheap personal shot at Mr. Raleigh notwithstanding, you are aware, are you not, that Airgo is one of the primary drivers of the 802.11n standard? This is an extension of the work they are putting into that standard, in fact, and which they are already selling in 802.11-pren products manufactured and sold by Linksys, Belkin, and so forth.
This guy is talking about something no more complex than using four radios at once and he's talking like it's the Second Coming.
MIMO is a heck of a lot more than just using four radios and combining their data rates together. This is about exploiting multipath to improve spectral efficiencies without widening the channel bandwidth.
Other people, who DON'T claim to design wireless hardware, I can forgive for not seeing that this article does a poor job of explaining what MIMO is. You should know better than to assume that they're trying to pass off simple channel bonding as MIMO, if you're really in the business.
Could someone please bonk him with a hardbound copy of the 802.11n standard?
Given he and his cohorts wrote a big chunk of it, I don't think that will be necessary.
This is pre-802.11n stuff, folks.
No, it is actually post-802.11n stuff. They already have their fingers in the 802.11 pie. What this may be, in fact, is an attempt to sway the standards body towards a standard that more closely hews to the Airgo approach, by demonstrating its scalability.
Wait for the real stuff to come out from established vendors who actually contributed to the standard,
That would include Airgo, actually.
Actually they're parallel processing the channel using arrays of virtual directional antennas, rather than multithreading (which has some degree of time-slicing implied, even with multiple instruction processors sharing data operation execution units).
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way