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Wireless Networking Hardware

802.11g Slows Down 310

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.
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802.11g Slows Down

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  • So... (Score:3, Insightful)

    by Anonymous Coward on Thursday May 22, 2003 @06:46PM (#6019390)
    How do they plan to market it against 802.11a? The advantage you were gaining in speed in exchange for distance is almost gone now.
    • As far as i can remember 802.11a isn't backwards compatible with 802.11b, whereas 802.11g is.
    • The real-world throughput of 802.11a and 802.11g is essentially the same.
  • Late? (Score:2, Interesting)

    Isn't 54mbps cards already on the market?

    • I think this standard might not matter anymore. Everyone seems to have settled on the preliminary standard, including Apple, the first company to heavily push 802.11b (and firewire, and USB...) The preliminary standard already has a pretty good head of steam and some surprisingly wide deployment, so in the end I think nobody is going to use this standard. There's no point.
  • So politics again get in the way of technology. Are there are there any firmware options that will allow the higher throughput? Or are we stuck with only a minor improvement?

    This sort of political wrangling has gotten in the way of so much decent technology. Wankel, hybrid and fuel cell engines come to mind.

    I understand the need for standardization, but it shouldn't limit the technology.
  • Lame (Score:2, Informative)

    by Vokbain ( 657712 )
    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. >:-(
    • Re:Lame (Score:5, Informative)

      by jat850 ( 589750 ) on Thursday May 22, 2003 @06:53PM (#6019439)
      Don't upgrade your firmware. You will be fine as long as you're in a 802.11g only environment. The problem comes when 802.11g devices coexist with 802.11b devices. As it is now, your hardware should be fine.
      • My linksys has an option to run an 802.11g network only. Dont see any reason to mix. Just worried that any new cards I buy wont support 56G as my current cards. Maybe I should go pick up a few before they get new roms.
  • Feh... screw backward compatibility. That's why Windows is Windows. 802.11b is, what, 11Mb/sec? So 10-20 MB/sec is hardly worth it. I say pedal to the metal.
    • by ttyRazor ( 20815 ) on Thursday May 22, 2003 @07:18PM (#6019609)
      802.11b's raw speed is 11Mb/s, actual thoroughput is only about 5 Mb/s. As far as I can tell, 802.11g's raw speed is still 54Mb/s, and even with the older "faster" firmware still actually had a throughput of ~20Mb/s, the only thing that's changed is the handling of mixed networks at 10Mb/s, which is still faster than 802.11b, just not the 4-5 times faster you'd expect.

      The whole point of 802.11g is backwards compatibility. The only way to screw it is to use another frequency, and that's what 802.11a is for.
  • Calling all Trolls (Score:4, Interesting)

    by evilviper ( 135110 ) on Thursday May 22, 2003 @06:49PM (#6019409) Journal
    This is the part where you begin to post the "802.11g is Dying" troll all across slashdot...

    Hey, if it's going to be newer, more expensive, with very little increase in speed, what's the point?

    Uhh, besides that, I'd be willing to bet most manufacturers will just say "screw it", and give their cards the full speed anyhow, standard be-dammed.
  • by Rick.C ( 626083 ) on Thursday May 22, 2003 @06:50PM (#6019417)
    The 802.11g standard includes built-in protection mechanisms to ensure that the devices don't interfere with older 802.11b devices. That means the 11g systems will need to transmit an electronic warning to 11b devices that a 11g device is operating, a warning that is enough to cause a cutback in actual throughput, Li said.

    I'm thinking that a flashing red light and a Sonalert going beep-beep-beep should be sufficient.

    Hey! Where y'all goin' with my bandwidth?
  • Crap. (Score:3, Interesting)

    by scumdamn ( 82357 ) on Thursday May 22, 2003 @06:50PM (#6019419)
    This is huge. I work in wireless at a bug company and we're sending 802.11g gear out the door now. We're billing it at 54, but now we're going to have to tell everybody who already bought it, "Hey, we sold this at 54, but it can really only do 20! Sorry!"
    This isn't going over well. People have been putting off 802.11a because they were waiting for 802.11g which was just as fast and had better range. Now they're left in the cold. I wonder what they're gonna do.
    • Re:Crap. (Score:2, Funny)

      by eli173 ( 125690 )
      > I work in wireless at a bug company and we're sending 802.11g gear out the door now.

      What kind of bug is that? Audio, even at a decent bit-rate wouldn't require the bandwidth. Hmm... perhaps a covert, live HDTV feed?

      Or the six-legged kind? Or the "It's a feature!" kind?

      ;P
    • Re:Crap. (Score:5, Insightful)

      by JoeBuck ( 7947 ) on Thursday May 22, 2003 @07:12PM (#6019557) Homepage

      802.11b is billed as 11, but it can only do 5. Make sure that you compare apples to apples. Even if the actual throughput is 10 Mbps, it's still double 802.11b's actual throughput.

    • Re:Crap. (Score:5, Funny)

      by Anonymous Coward on Thursday May 22, 2003 @07:19PM (#6019614)
      > I work in wireless at a bug company

      How are things at Microsoft?
    • Tough! (Score:4, Interesting)

      by sterno ( 16320 ) on Thursday May 22, 2003 @07:47PM (#6019823) Homepage
      TS. It wasn't a ratified standard. Too bad. I mean seriously, if you implement non-standard systems, this is the price you pay. If you didn't point out to your customers that what you were selling them wasn't a ratified standard, then it's your butt in the sling when they complain.
      • Re:Tough! (Score:3, Insightful)

        by Archfeld ( 6757 ) *
        Ratified standard or not the hardware was manufactured and sold by a company making claims to 45 Mbps. I'd just take it back, 40% of the advertised thoughput IS NOT AN ACCEPTABLE margin.
        • Advertisers say the car I bought can do 180 MPH. Just because I can not legally go above 70 MPH on the freeway doens't mean that the advertising was false or that the car is only capable of 40% of its advertised throughput.

          Similiarly, I'm sure the devices produced by "Bug Company" can do 45Mbps -- just because that speed is over the standard limit, doesn't make the advertising any less true.

          Modems are another fine example of this. Most modems routinely connect as speeds less than their advertised speed
    • Now they're left in the cold. I wonder what they're gonna do.

      What? Capitalists lying to make profits? No! Say it ain't so..

      I'll tell you what they're going to do. They're going to continue being mindless consumers paying for whatever has the most pretty packaging.

      I just wonder why these people are still in charge of making purchasing decisions for any corporation in this economy.
  • In other news... (Score:5, Informative)

    by djupedal ( 584558 ) on Thursday May 22, 2003 @06:50PM (#6019420)
  • OK call me a sceptic but at a 2x to 4x throughput thats not a huge leap what would be the incentive to bother? Sure if it's pretty cost neutral install g for the new gear. Most people would seem to stick with there functional b gear and leave it at that till it natrual progresses over to a g network or someing fast comes out like a,b,g chipsets.
  • ridiculous (Score:3, Interesting)

    by meta-monkey ( 321000 ) on Thursday May 22, 2003 @06:51PM (#6019428) Journal
    Terrible. I've got a Mac and a airport extreme base station. If they try to change it from 54Mbps to something ridiculous like 20Mbps, I'm just not updating my firmware and drivers. Forget that, I paid for the speed, I want the speed!
    • Re:ridiculous (Score:5, Interesting)

      by ocelotbob ( 173602 ) <ocelot@ocel3.1415926otbob.org minus pi> on Thursday May 22, 2003 @07:11PM (#6019553) Homepage
      The headline is more than a bit sensationalist; 802.11g still tops out at 54mbps. It's just that in a network with 802.11b equipment, it'll throttle back to 10-20Mbps. It's not quite as bad as you think it is, but you still may want to look at getting a 3rd party hardware solution. If you've got legacy equipment, you may want to consider picking up an 802.11a hub for your high speed equipment. I always thought that apple was silly by offering just 802.11g when all the chipset vendors have said that they're going to be offering combo solutions. Hell, a combo solution, used properly, can provide speeds of over 100Mbps. Someone's just got to create multilink support, much like the old trick of getting 2+ phone lines for dialup and using multilink PPP.
  • Thats Crazy! (Score:3, Insightful)

    by zbowling ( 597617 ) * <zac@zacbowCOUGARling.com minus cat> on Thursday May 22, 2003 @06:52PM (#6019431) Homepage Journal
    I got my Wireless 11g Router (Linksys WRT54G) and PCI card (SMC2802W) for my pc upstairs and I always connect at 54 mbs (according to the software). According to the artical, it says that the Wireless g devices have to send out a warning to the wireless b devices which is what will cause the drop in speed. I say screw the warning. If a wireless b device messes up, they need to upgrade to g. Instead of kill the speed of g for the courtousy of b devices, but phase out b tech really quickly. I will take my stuff back and just run a cat9 line upstairs instead if I'm reduced below even what my ISP gives me. They need to find another solution quick or I won't upgrade my firmware and those b devices can just take it up the #%@%.

    I would like to say I'm sorry to the other /.ers if I come off mad, but I was really excited about my new toys. I knew the risks of buying a draft technology, but I didn't think that the speed would go down to basicly nill.

    • Instead of kill the speed of g for the courtousy of b devices, but phase out b tech really quickly.

      If you wanted speed at the cost of compatability, you should have bought 802.11a, which ignores 802.11b devices, just like you say 802.11g should. Also consider the huge base of installed 802.11b.

    • The article kinda has it backwards, it's b equipment that will slow down and interfere with g equipment. The problem is that without the warning, the b device will still try to transmit, which will collide with the g device's transmission, and they'll both have to retramsit all over again.

      Over half the thoroughput of any flavor of 802.11 is devoted to determining which device gets to transmit when, without which they'd all just transmit on top of each other and slow each other down even further, which is
      • I can see it now.

        Instead of 'who farted?' being the big question at the coffee house now, the unpleasant question everbody will ask is 'who's running the 802.11b card?
    • If a wireless b device messes up, they need to upgrade

      The above-quited opinion is fully explained in the poster's sig, quoted below:
      Zac Bowling
      MCSD,MCSE
  • by John3 ( 85454 ) <john3@cornel l s .com> on Thursday May 22, 2003 @06:52PM (#6019434) Homepage Journal
    It almost seems that the new standard will more accurately reflect the real throughput for these devices, especially in mixed 802.11b/g environments. It's better to lower the expectations now before people purchase and are disappointed. I've read plenty of comments at amazon.com from purchasers of 802.11g access points where they were surprised that "backwards compatable" meant that mixing the b/g would make everything run slower.
    • It almost seems that the new standard will more accurately reflect the real throughput for these devices, especially in mixed 802.11b/g environments. It's better to lower the expectations now before people purchase and are disappointed. I've read plenty of comments at amazon.com from purchasers of 802.11g access points where they were surprised that "backwards compatable" meant that mixing the b/g would make everything run slower.

      Dunno about that, but at the end of the article from Computerworld, it menti

  • That renders the protocol nearly purposeless. It really isn't that much faster, to make it worth switching to from 802.11b. I am especially incensed because I opted to get the 'g' card in my Powerbook a few months ago. At least it is backwards compatible with 'b'.
  • This sucks (Score:4, Interesting)

    by djward ( 251728 ) on Thursday May 22, 2003 @06:53PM (#6019438)
    A lot of people have probably already invested a lot of money in 802.11g equipment because of the 54mbps rate, and now, if they have a mixed environment, will end up with a slower rate than they had with 802.11b (10mbps vs 11mbps). I guess this is the fault of the industry for making promises and shipping equipment before the standards are finalized, but this greatly shrinks the market for 802.11g upgrades.

    [dons tin-foil hat] I wonder if the 802.11a proponents *ahem* persuaded the IEEE to do this because they might have lost a lot of invested time/money if 802.11g took over the world... [/tin-foil hat]
    • Re:This sucks (Score:3, Informative)

      by JoeBuck ( 7947 )

      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.

      • Sure, so maybe it's a small improvement, not a slowdown, but it ain't what it could have been, and many will feel that it is not a big enough jump to warrant the extra cost.
  • by cruppel ( 603595 ) on Thursday May 22, 2003 @06:53PM (#6019443) Homepage

    Just plug in a cable. While I admit (by the time this posts, like seven other people before me) that knocking it down below one half of the original throughput is weird, 54Mbps is not neccessary. If I need 54Mbps I'll just grab an ethernet cable.

    Normal/casual connections need no more than a megabit per second anyway. Browsing, SSH, IM etc does not require a enormous connection. Maybe if there were a "safe mode" there would be both safety for 11b and speed when only 11g is present in the area.

    • by ciroknight ( 601098 ) on Thursday May 22, 2003 @07:04PM (#6019504)
      But I need that bandwidth... and I need it MOBILE!!! It'd be really nice to be able get in my car and drive between work, school and home, and have constant access to the internet, but it would be practically useless if I couldn't actually do anything with it more than check email and read /. I want to be able to hear a song on the radio, then, before I forget it, download and have it! Novel idea indeed.

      My next qualm is, all the cables in my room. Since my "media center" has at least 50 different cables running behind it (ethernet, coax for modem and tv, power, monitor, usb, etc), I'de love to get rid of at least some of them. And as bluetooth gets better, I can get rid of the cables for just about everything else (except power). I happen to have a nice and speedy 100MBit connection to my campus network, I'de hate to give that up for 20Mbps just because my wireless system won't let me reach those limits. (For all of you who say "100MBit is impossible in most cases, we use about a good 60Mbps on average, filesharing mostly.) But that's really the only reason for me to have wireless, so if it's not fast, it's wasted.
      • But I need that bandwidth... and I need it MOBILE!!! It'd be really nice to be able get in my car and drive between work, school and home, and have constant access to the internet, but it would be practically useless if I couldn't actually do anything with it more than check email and read /. I want to be able to hear a song on the radio, then, before I forget it, download and have it!

        I think you have confused 'need' with 'want'.
    • Picture an office using high speed wireless. They could pick up shop and move someplace else if need be without worrying about it being wired.

      Granted most office space is/should be wired, but by choosing a place that isn't could save you a lot of money. You might even want to have your business very mobile.

      Just a thought.
      • Granted most office space is/should be wired, but by choosing a place that isn't could save you a lot of money. You might even want to have your business very mobile

        Just a thought.


        And and incorrect one at that. Cabling is a very minor cost in the total makeup of moving an office. And proper setup of wireless access points (yes, there is more to it than putting an AP on a desk in each corner of the building or wherever you notice a dead spot) will cost far more than dropping cable. And if you really h
    • by Keeper ( 56691 ) on Thursday May 22, 2003 @08:21PM (#6020059)
      Why not just run a cable? Because people like me who live in an apartment don't want to trip over an ethernet cable every time they walk from the living room to the kitchen ...

      I personally want to have all of the big toys in the computer room, with a media pc of some sort in the living room. On top of that I'd like to have a laptop using desktop sharing and use any computer wherever I want, should I so desire. It works ok on 802.11b, but it sure as hell would be better with more bandwidth.
      • Why not just run a cable? Because people like me who live in an apartment don't want to trip over an ethernet cable every time they walk from the living room to the kitchen ...

        Wow, you must be prety damned disorganised, and that's me saying that (of course, you don't know me. Meh).

        When I was sharing a student flat (really a small house) with 2 other nerds, we networked up the place with loads of coax cable. 10-base-2. Slower than what you people* are complaining about facing from your wireless connectio

  • by avi33 ( 116048 ) on Thursday May 22, 2003 @06:54PM (#6019451) Homepage
    hm.

    U.S. Robotics has a free software upgrade for their 802.11b products [usr.com], 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 .g.

    That makes 802.11b about 50% cheaper, some degree safer, and 100% faster? I think I'll skip this upgrade for now.
  • by fastpathguru ( 617905 ) on Thursday May 22, 2003 @06:55PM (#6019452)
    ...Intel went and stuck themselves with an 802.11b Centrino soloution. Hmmm... fpg
  • by loggia ( 309962 ) on Thursday May 22, 2003 @06:55PM (#6019456)
    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.

  • early vendors (Score:2, Interesting)

    just goes to show you the danjour of making your products before the IEEE spec is released . It screwed up novell , and now it looks like it screwed up the wireless companies . Are we going to have 802.11g "54mbs variety" or draft 2 version etc. Anyw ays like most people say this certainly will push me away from 802.11g gear , I can get cheap 802.11b access points which are only half the speed , with 54mbs it was close enough to "lan speed" for me to consider the extra $100 , but now its 802.11b all the way
  • by craenor ( 623901 ) on Thursday May 22, 2003 @06:56PM (#6019463) Homepage
    90% of these are going to go into homes. And both 802.11b and 802.11g give you more throughput then the average user will get from their ISP. So in the end, I don't think it will matter to most people...
    • You are right when it comes to just surfing the Internet, but a lot of people use wireless in their homes to transfer files between computers. In that case, it is a pretty big different and will be felt.

      Now that they took away any speed advantage to upgrade, wonder if they will at least improve upon latency.
  • by jolyonr ( 560227 ) on Thursday May 22, 2003 @06:56PM (#6019466) Homepage
    It appears from the comments here that quite a few people haven't bothered to read the article (slashdot users commenting before reading the article? there's a suprise!).

    This is NOT a proposal that's going to slow down all the 54Mbps cards out there to 10-20Mbps, all it's saying is "Hey, we were a little optimistic, these g cards have never been 54Mbps, and it would be a little more honest at this point to tell people that they're only 10Mbps-20Mbps cards."

    So hold off on your firmware upgrades if you wish, but you still won't have 54Mpbs wireless!

    Jolyon
  • Theoretical vs. Real (Score:2, Interesting)

    by mdw162 ( 654188 )
    I'm not at all familiar with the real-life speeds 802.11g can currently provide, but maybe the new spec, while theoretically slower, will have other benefits. Maybe it'll be more reliable and more consistent. Maybe in everyday use it really will be faster. Seriously, does anyone really see 54Mbps curently?
  • What's the cost difference between 'a' and 'g'? I understand the advantage of having 'g' work with 'b' but if you're building from the ground up?
  • I've been seriously looking at setting up a wireless-capable Router in my home and noticed that all the ones I have seen totally step down from 802.11g to 802.11b if one 802.11b device is connected.

    In other words, if you've got twenty 802.11g devices connected wirelessly and one 802.11b device connects, everyone starts running at 802.11b speeds.

    That's not going to stop me, but I though the /. community might find that interesting.
  • by toybuilder ( 161045 ) on Thursday May 22, 2003 @07:12PM (#6019556)
    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.

  • by RiBread ( 181983 ) on Thursday May 22, 2003 @07:13PM (#6019564)


    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 .11g solution is probably barely reaching 8 Mb/s in a mixed mode network and confusing the hell out of any .11b stations listening. You'd be silly not to upgrade the firmware as soon as they provide it.

    The standards body hasn't throttled down .11g 's PHY level data rate; theoreticly 54Mb/s worth of info is still being spit out into the air. What they've done is added a little bit more overhead so that the .11g stations don't completely butt out the .11b stations.

    Still, by the end of the summer you'll see throughput at 30 Mb/s in pure .11g, with 15 Mb/s mixed mode (without adversly affecting .11b stations). The leader of the pack should be Texas Instrument's chipset [ti.com], hopefully to appear in DLink's newest 11g offering.

    In a pure .11g network you won't get 54Mb/s but if you use TI's chipset you'll get throughput approaching 30 Mb/s.

    The compatability
  • by mcmasuda ( 126879 ) on Thursday May 22, 2003 @07:16PM (#6019584)
    Everybody's going on and on about how it's hardly faster than .11b. Read the freakin article:

    "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 .11b is about 5Mbps true throughput. .11g will be twice that in "safe mode" and four times that in pure .11g mode.

    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.
  • by Ryan C. ( 159039 ) on Thursday May 22, 2003 @07:16PM (#6019589)
    The post and article compare incompatible metrics, 54Mbps is the theoretical bandwith, vs. 20Mbps measured throughput. The maximum throughput of the draft devices is between 22-24Mbps. The new 10Mbps mode is only when an 802.11b network is detected in the same channel, which is better than the nasty and unpredictable timeslicing that happens with most draft equipment. So... real speed loss = 22-24 to 20. Bad, but not that bad.

    -Ryan C.
  • This is a very bad choice.

    Right now I have an 802.11b access point that can do 22Mbps with other Dlink stuff. I recently installed newer firmware on it that supposedly made it even faster. The only problem is that the extensions to make it go faster are not standard. Thus, my Linksys card will never be able to connect at 22Mbps.

    By dropping the 802.11g standard down to twice the speed of 802.11b they're just causing the market to fragment. Everyone is going to develop different propritary extensions
  • So, like, what happened to c-f? Did those like totally suck, or what?
  • WHAT?!?!?!?! This is totally unfair! I don't care if faster speeds step on peoples' toes. I want my faster speed!

    Actually, I can understand the reasons for doing this. IIRC, 802.11x works on frequencies that are for "public" use, and as such, producing too much junk in the air could (and probably) will screw up all kinds of other services, seeing how this technology will probably spread to cover all populated areas. I may be confusing this with a different technology, so please excuse me if I am... It's

  • by scrotch ( 605605 ) on Thursday May 22, 2003 @07:39PM (#6019747)
    I can't wait til there's an over-clocking culture for G cards.

    31337 haxors will be rewriting drivers and soldering on old cordless phone antennas and adding fans and paint to their cards. We'll have web pages about how you can increase range with a 9v battery and get maximum speed with a driver mod, ventilated card-case and a pringles can.

    this is gonna rock.
  • Having already deployed draft 802.11g equipment from Linksys in a small office, I can tell you that the actual throughput is already around 20Mbps for a pure-g environment. (Haven't tried it mixed with b).

    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:

    • 802.11b
      • Raw Data Rate: 11Mbps
      • Actual Throughput: 5-6Mbps
    • 802.11g (pure)
      • Raw Data Rate: 54Mbps
      • Actual Throughput: 20Mbps
    • 802.11g (mixed with b)
      • Raw Data Rate: 54Mbps
      • Actual Throughput: 10Mbps

    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 [computerworld.com] at [computerworld.com] his [computerworld.com] past [computerworld.com] articles [computerworld.com] 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...

  • by Eric Smith ( 4379 ) * on Thursday May 22, 2003 @08:29PM (#6020110) Homepage Journal
    The numbers quoted in the article aren't measuring the same thing. 802.11g has a raw data rate of 54 Mbps, but it was never the case that you could get 54 Mbps throughput. Typical products got 20-22 Mbps throughput. Just as typical 802.11b products get around 5 Mbps throughput from an 11 Mbps raw data rate.

    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.

  • by eggboard ( 315140 ) on Thursday May 22, 2003 @08:34PM (#6020134) Homepage
    The encoding is at 54 Mbps: number of symbols per second, right? The throughput is the actual data rate that contains information exclusive of error correction and framing.

    802.11g has produced 10 to 25 Mbps of throughput since they started working with 54 Mbps encodings.

    This is a total misunderstanding, unfortunately, of both the article (which states the problem almost correctly) and its consequences.

    Read any good article about 802.11g since it started shipping in draft form, and you'll see that a net throughput of 25 Mbps or less (much less in mixed b/g environments) was always what was produced.
  • by jbuilder ( 81344 ) <evadnikufesin@gmai l . com> on Thursday May 22, 2003 @09:24PM (#6020472)
    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.

  • HELLO? (Score:3, Informative)

    by moosesocks ( 264553 ) on Thursday May 22, 2003 @09:39PM (#6020540) Homepage
    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.
  • Seems like they should have called it 802.11e or something.
  • News??? (Score:5, Informative)

    by NetFu ( 155538 ) on Thursday May 22, 2003 @09:52PM (#6020609) Homepage Journal
    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)

"Card readers? We don't need no stinking card readers." -- Peter da Silva (at the National Academy of Sciencies, 1965, in a particularly vivid fantasy)

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