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802.11g Slows Down
Moosifer writes "Computerworld reports that in order to step on fewer 802.11b toes, the IEEE has reduced the actual throughput of 802.11g in its latest (and allegedly final) draft. I think I might keep old firmware on my linksys AP and card so that I can at least pretend I have faster gear." It's been moved from 54Mbps all the way down to 10-20Mbps, more than just a slight change.
I bought my Airport Extreme hub because I wanted mad speed. This completely defeats the purpose. I might as well have bought a regular 802.11b hub for half the price. >:-(
US Robotics doubles up on 802.11g data rates
I don't think this has much to do with politics. Reading the article, it looks like a backwards-compatibility issue such that 802.11g devices don't interfere with 802.11b devices in a co-existing environment.
the blood has stopped pumping, and he's left to decay
the me that you know is now made up of wires
hm.
.g.
U.S. Robotics has a free software upgrade for their 802.11b products, getting it up to about 54+ Mbps (ok, so you have to run it in a homogenous USR-upgraded 802.11b environment to get 54 Mbps throughput). You can also run 256-bit WEP as a bonus, something not available in
That makes 802.11b about 50% cheaper, some degree safer, and 100% faster? I think I'll skip this upgrade for now.
802.11g is not and never has been 54Mps.
The effective throughput of 802.11 is about 22Mps.
54Mps is the effective raw bandwidth.
I have no idea what the new changes will do the speeds of 802.11g, but no one is or has ever gotten 54Mps.
The early parts don't seem to work too well in mixed 802.11b/g networks, seem to go at the .11b speeds all the time. So the real question is whether you still get a hit in a pure .11g network, which is unclear from the article.
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Yha, but don't forget how the industry did upgrading modems.
9600 to 14.4, 28.8 to 33.6.
Sure, when it went from 300bps to 1200bps it made a big difference... but a lot of modems were sold going from 9600 to 14.4.
Heavy users wnat the advantage, dumb consumers go for "larger number better".
http://www.proxim.com/products/all/orinoco/client/ abgcard/index.html
Microsoft Windows runs on stress and frustration.
Guys,
The 54Mbps is the signal rate of the 802.11g modulation scheme. With the per-packet overhead, the effective data rate is around 20 Mbps, and they're trying to clarify that to consumers.
FastEthernet is 100 Mbps, right? Well, actually, the signal rate on 100Base-TX is 125 Mbps. It takes 5 bits on the cable to carry 4 bits of actual payload data.
The rate on the box != the actual throughput you get.
Due to protocol overhead, backwards compatability overhead, physical environment, yada yada yada, you'll see varying throughput.
With current implementations of the draft solution mixed mode performance is *terrible*. 10 Mb/s mixed mode is an improvement. Right now your draft
The standards body hasn't throttled down
Still, by the end of the summer you'll see throughput at 30 Mb/s in pure
In a pure
The compatability
You did not read carefully: you are comparing an actual throughput number (10 mbps for a mixed b/g network) to a raw, theoretical data rate number (11 mbps for b). In practice, the actual throughput on an 802.11b network is about 5 mbps.
Everybody's going on and on about how it's hardly faster than .11b. Read the freakin article:
.11b is about 5Mbps true throughput. .11g will be twice that in "safe mode" and four times that in pure .11g mode.
"Li estimated that that in mixed 802.11b and 802.11g networks running standard TCP/IP Internet protocols, this will reduce actual throughput to 10Mbit/sec. -- while pure 802.11g networks will have actual data rates of around 20Mbit/sec. Li pointed out that even at these data rates the 802.11g devices still outperform 802.11b devices, which have a raw data rate of 11Mbit/sec. but an actual throughput of about half that speed. "
See that? He's saying
The article would have been much clearer if he had said ".11g is being reduced from 54Mbps raw data rate to X Mbps raw data rate, and from Y Mbps true throughput to 10 or 20Mbps true throughput." Instead he says it's getting reduced from 54Mbps raw data rate to 10 or 20Mbps true throughput. Way to mismatch your units to get the biggest reduction possible.
The article says (my emphasis):
Yuck.No, I mean the thing that 'g' still has over 'a' is that you can connect to 'b' networks with a 'g' card. It was part of the original spec. As far as I can remember, you can't connect to a 'b' network with an 'a' card.
Which means even though they have the lower speeds now, 'g' is still superior to 'a' in some ways.
Malike Bamiyi wanted my assistance.
The problem here is just that the reporter seems to be twisting the numbers to try to make it sound worse than it is. His very first sentence compares "true throughput for Internet-type connections of between 10M and 20Mbit/sec" with "54Mbit/sec. raw data rate", which is misleading. Raw data rate and actual throughput are (unfortunately) only vaguely related. If you want accurate numbers for g and b, compare apples to apples. According to the article, if you pay close enough attention, the real numbers are:
Now, maybe in earlier drafts the actual throughput numbers for 802.11g were supposed to be higher, but you wouldn't know it from reading the article. Looking at his past articles it seems like the reporter might just not know the difference, he uses 'throughput', 'data', 'data rate', 'raw data rate', 'data speeds', 'raw data speeds', and 'bandwidth' all interchangeably. The differences between some of those are subtle (or non-existent), but if he's confused enough then comparing 'raw data rate' to 'actual throughput' could conceivably have been an honest mistake...
So if they made some change to the final 802.11g standard such that the througput is only 20 Mbps, that's not much of a change from the draft.
And it has always been the case that in a mixed enviornment (802.11b coexisting with 802.11g), you can't get maximum 802.11g throughput. The exact amount of slowdown will vary.
So in summary, I'm not convinced that anything this Computerworld article is reporting about the 802.11g standard is actually a significant change from the draft. They've just compared some numbers in a meaningless way to sensationalize the story.
Disclaimer: At work I'm involved in the development of 802.11g products.
It's just that in a network with 802.11b equipment, it'll throttle back to 10-20Mbps.
You should be *very* afraid of this. If an ISP decides to put a high-power 802.11b network in your town, your 802.11g router has just retarded itself back to 802.11b speeds. Think about it this way, when the FCC gave the OK for 900mhz cordless phones, they worked great *UNTIL* AT&T got the OK to use the same frequency range for cell phones. Then all of those home cordless phones became static-ridden junk. We're going to have the same level of saturation in the next few years for the 2.4ghz band (the band that the current cordless phones AND 802.11 routers use).
I can just see the complaints being filed with the FCC as all of this wireless equipment we're buying starts going to pot on us because we have this giant radio signal "collision domain" that we're going to use up.
Polymorphism -- It's what you make of it.
I'm not sure why everybody here is panicing, and vowing not to upgrade firmware. IEEE is not planning on changine the manner in which the 802.11g protocol communicates - they simply want to revise their published specs on the realisticamount of bandwidth which the protocol is capable of (it's still CAPABLE of 54mbps, but this will NEVER realisitcally happen).
Look at other protocols; 802.11b can't do anything near 11mbps, or even half that. Fast Ethernet actually runs at 125mbps, but achieves a real-world throughput of 100mbps. ATA transfer rates are pitiful compared to their published 'capabilities'; very few ATA devices exist that can even achieve 66mbps, while the spec has already been inflated to 133mbps. However, the more 'professional' standards live up to their quoted specs much better (ie. firewire and scsi).
In short, all 802.11g hardware will continue to operate in the same fashion. The IEEE simply doesn't want to be making false claims.
-- If you try to fail and succeed, which have you done? - Uli's moose
Is this even really news?
At work we've been using 802.11a and 802.11g devices (not to mention 802.11b) since the absolute first days they were each available. All the testing I've ever done was far from impressive and probably close to what they are saying in this article:
802.11b
Advertised Speed: 11 megabit or 1.38 megabytes/sec
Advertised Range: 150 feet
Real-world Speed: 4.5 megabit or 0.55 megabytes/sec
Real-world Range: 100-250 feet depending on interference
802.11a
Advertised Speed: 54 megabit or 6.75 megabytes/sec
Advertised Range: 150 feet
Real-world Speed: 21.5 megabit or 2.7 megabytes/sec
Real-world Range: 50-100 feet (outside of that and the link is so weak the real throughput is worse than 802.11b)
802.11g
Advertised Speed: 54 megabit or 6.75 megabytes/sec
Advertised Range: 150 feet
Real-world Speed: 19.5 megabit or 2.45 megabytes/sec
Real-world Range: 100-200 feet (at 200 feet you can still get better than 802.11b throughput, while 802.11a usually is completely gone at 100 feet unless you are in an open field)
The reality is that they had better start advertising the true speeds and problems of 802.11a/g because a lot of people get disappointed when they compare them to standard 100Base-T wired connections -- to me it's flat-out false advertising. The real-world range of 802.11g is similar to 802.11b and its real-world throughput is consistently 3-5 times faster than 802.11b.
But to say that 802.11a/g are "54 megabit" so people compare them to a 100 megabit ethernet connection is REALLY wrong. It reminds me of the "56k" modems we have in our computers that never connect faster than 40k-45k for most people.
(for the record, our wired 100Base-T network that all these devices are plugged into is very fast -- we have no problem getting 8 to 11.5 megabytes-per-second of throughput)
This just changes what you thought you were getting.
Before:
Mixed 'b' and 'g' you got ~5Mbps throughput, ~22Mbps otherwise.
Now:
Mixed 'b' and 'g' you get ~10Mbps throughput, ~20 otherwise.
Actual performance for an all 'g' network hasn't changed, just the official estimates from the IEEE. And now it does about 2x as good in a mixed 'b' and 'g' network.
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Solution #2.
HTH!
If you could be told what you can see or read, then it follows that you could be told what to say or think - BoC
this is 16mbps, which is less than the 10-12 mentioned, which is my point.
actually 10 and 12 are both less than 16 (in addition to being farther from 20).
54mb *(1B/8b) = 6.75 MB So don't bother to say you ment 10-12MB.
No no no, I understand that perfectly (I study Computer Science).
By that do you mean that you do 1337 mods like coloring your case with crayolas? Or do you mean I know all about computer science, I just can't do simple math?