Final 802.11g draft standard throttles datarates DOWN

Discussion in 'Macintosh Computers' started by Chef Ramen, May 22, 2003.

  1. Chef Ramen macrumors member

    Dec 21, 2002

    Final 802.11g draft standard throttles data rates down

    The lower throughput is needed to protect 802.11b WLAN gear

    By Bob Brewin
    MAY 22, 2003
    The Institute of Electrical and Electronics Engineers Inc. (IEEE) has approved a new and final draft standard for 802.11g wireless LANs that will have a true throughput for Internet-type connections of between 10M and 20Mbit/sec., far lower than 54Mbit/sec. raw data rate initially billed for the standard.

    The standard was approved by the IEEE on May 15 but won't be made publicly available until members of the IEEE 802.11 working group ratify it next month, according to Sheung Li, a product line manager at Atheros Communications Inc., a Sunnyvale, Calif-based WLAN chip manufacture.

    Li said the lower actual vs. raw data rates for 802.11g arose from the need to assure backward compatibility with millions of existing 802.11b Wi-Fi client devices and access points that operate in the same 2.4-GHz frequency band. 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.

    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.

    Randy Conklin, director of operations for Broadband Central, a wireless Internet service provider based in Draper, Utah, that serves seven western states with a network built around wireless LAN gear, said the10Mbit/sec. data rate for 802.11g isn't good enough for advanced applications such as voice over IP or video. To support those applications, Broadband Central would need at least 20Mbit/sec. data rates, he said. As a result, the service provider will look to deploy pure 802.11g service offering the faster data rates.

    Pat Hurley, an analyst at TeleChoice in Boston, said companies looking for higher speeds from their WLANs should consider using hardware based on the 802.11a standard, which provides a real data rate of about 24Mbit/sec. in the 5-GHz band. Hurley said companies starting from scratch could consider a combined 802.11a/g network, which would offer two options for high data rates in a campus environment as well as the ability to access 802.11b hot spots while on the road -- since 802.11g clients can operate with 802.11b access points.

    However, 802.11a devices operate in a different frequency band than the 11b and 11g devices, meaning they aren't compatible with them.

    Atheros has already shipped prestandard 802.11g chip sets to WLAN manufactures, such as D-Link Corp. in Taipei, Taiwan. Li said end users would only need to download a software driver to update their 802.11g cars with the new standard.

    Jeff Abramowitz, director of wireless LAN marketing at Broadcom Corp. in Irvine, Calf., which supplies WLAN chip sets for PC cards used by Dell Computer Corp., said end users of prestandard Broadcom 802.11g chips will also need to download new drivers to make their older gear compatible with the final IEEE standard.

    Another computer maker, Apple Computer Inc., has also released devices using the 802.11g standard -- and has promised that its customers will also be able to upgrade to the final standard once it's in place.

    Bill Carney, director of wireless LAN marketing at Texas Instruments Inc. in Dallas, said his company has decided to wait until the IEEE ratifies the 802.11g standard and expects to start shipping standard-compliant chip sets in July.

    Brian Grimm, spokesman for the Wi-Fi Alliance in Mountain View, Calif., said the alliance expects to start testing and certifying 802.11g products in June.
  2. baby duck monge macrumors 68000

    baby duck monge

    Feb 16, 2003
    Memphis, TN
    sounds pretty bad to me, but i am not sure i completely understand. are they saying that people who already have, say, and APE card will download some sort of firmware that will decrease their maximum transfer rate? i understand that almost no one would be getting 54 mb/sec anyway, but if i had gotten APE hardware, i would be mad if it got limited like that all of the sudden. or maybe i am wrong? anyone care to explain it?
  3. sparkleytone macrumors 68020


    Oct 28, 2001
    Greensboro, NC
    this is NOT good news. steve jobs himself advertised this at 54mbps, and as someone who uses 802.11a at work, i can tell you the extra bandwidth is NICE on a LAN. i'm sure hes more pissed than i can even imagine. this better get fixed. fast.
  4. LethalWolfe macrumors G3


    Jan 11, 2002
    Los Angeles
    I guess this is the risk you take for adopting something before the final standard is set.

  5. nikfel macrumors member

    Apr 11, 2003
    Does this mean now is the time to buy an Airport Extreme Base and Card. Does it also mean people should not update the firmware if an update becomes available!!!
  6. szark macrumors 68030


    May 14, 2002
    Disappointing that they couldn't find some other way around the problem.

    This makes 802.11g nearly useless, IMHO. Certainly far fewer companies will consider adopting it, and probably go for 802.11a instead.
  7. Freg3000 macrumors 68000


    Sep 22, 2002
    New York
    Bad Bad Bad Bad Bad Bad Bad. I just got an AE card, and used a B base station, waiting for G to be finalized. But now.....this is bad.....really bad. Especially since Steve danced around on stage for 5 minutes about 54 Mbps.

    Bad Bad Bad!
  8. jhershauer macrumors member

    Feb 3, 2003
    Gilbert, AZ
    Doesn't seem THAT bad

    I guess there are two threads on this topic. Anyway, here's my take...

    True throughput never was 54 Mb/s. It doesn't look like they've slowed it down very much. They're just saying an extra "warning message" was put in to notify 802.11b devices that an 802.11g device is running.

    The article states that true throughput will probably be about 20 Mb/s for a dedicated 802.11g network. Isn't it about 22-24 Mb/s right now? I don't think the difference will mean much to the average home user. It's still way faster than 802.11b.

    Even on a mixed network, they're talking about getting true throughput of 10 Mb/s. That's still much better than the 4-5 Mb/s or so that I'm getting right now with my 802.11b network.

    [Edit] Note that 802.11a is around 24 Mb/s. While the 17% difference between a and g might keep 802.11a alive and kicking (especially in the business world), I don't think it's a big enough difference to declare 802.11g "useless".

  9. jhershauer macrumors member

    Feb 3, 2003
    Gilbert, AZ
    Terrible wording used in article

    The wording used to start off the article is horrible, and is going to give a lot of people the wrong impression. The author attempts to compare old/new speed with mixed terms ("raw data rate" vs. "true throughput".

    The raw data rate isn't changing. It's still 54 Mb/s. The true throughput is dropping something like 9 to 17%.
  10. gbojim macrumors 6502

    Jan 30, 2002
    Re: Doesn't seem THAT bad

    Exactly. There is a big difference between raw data rate and actual throughput.
  11. bbarnhart macrumors 6502a


    Jan 16, 2002
    Can anyone here test their AirPort Extreame now and see what they are getting? I doubt it is 54 mb/s.
  12. smada macrumors member

    May 7, 2003
    im getting 36 mbps right now from a base station on the other side of the house.

    this is disappointing. I'm going to try and avoid updating if possible.
  13. sparkleytone macrumors 68020


    Oct 28, 2001
    Greensboro, NC
    if it is indeed the wording, then i can hopefully retract my statement ;)

    the big problem then lies in the 'expert' who suggests 802.11a as a better solution.
  14. jhershauer macrumors member

    Feb 3, 2003
    Gilbert, AZ
    He's just talking about companies that need every bit of bandwidth they can get. For some people/companies, the 24 Mb/s from 802.11a will be worth buying over the 20 Mb/s 802.11g. For others, the compatibility between 802.11g and 802.11b, or the lower costs of g vs. a will be the determining factor.
  15. maradong macrumors 65816


    Mar 7, 2003
    well the downgrade of the bandwidth is also good, as the standart will be used by more people than the one from apple, and this garanties a better stability and better signal. as
  16. voicegy macrumors 65816


    Jan 1, 2002
    Sandy Eggo - MacRumors Member since 1-1-2002
    That's one of the reasons we decided to abandon the AirPort Base Station as a wireless access point for my school district. A non standardized protocol, along with a high price, just pushed us to standardize with Orinoco access points. Seems that we made the right decision, but it was not a good move on Apple's part.

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