802.11g... It's Official

JoeBuck writes "This article in CommsDesign reports that the IEEE has officially approved the IEEE 802.11g standard, as well as another standard (802.15.3) for shorter-range, very-low-power operation. Two other standards designed to improve compatibility between different vendors' access points were also approved."

Comments

Good news and bad news...

[NumberField]

802.11g operates at the same frequency as 802.11b. The good news: existing antennas and other range extension techniques should work fine (Pringles can, anyone?). The bad news: interference is going to be a nightmare. In heavily-populated areas, it's common to have a dozen or more legacy 802.11b signals, which tend to hog the bandwidth that would otherwise be available for .11g. Add in microwave ovens (which interfere massively on the same band), and many people will be lucky to see even 20 Mbits/sec. The security is also a mixed bag: although the WEP mess is improved, security is still going to be a headache, particularly for people who want to roam safely.

IEEE Page

[acherrington]

Here is the link to IEEE

http://standards.ieee.org/announcements/80211gfina l.html

ENJOY

News reporters

[chiph]

For those reporters out there who will write stories about this for "joe consumer":
The "g" in 802.11g stands for "gamma", and no, the IEEE did not skip over proposals 802.11c, d, e, & f before settling on "g".

Chip H.

Re:compatability with current products?

[Pirogoeth]

Apple has stated that they will be releasing a firmware soon to update to the official spec. I would assume that other vendors would be following suit.

Re:Good job, Apple.

[Pirogoeth]

This story kind of explains the speed thing. The actual throughput speed has not changed at all since 802.11g first came out.

Another standard

[Boing]

Importantly, one of the two other standards was for decreasing conflicts between WLAN and WPAN devices operating on the same part of the spectrum (802.11(b|g), 802.15.3, and Bluetooth, for example). Hopefully some vendors will include the collaborative mechanisms (where the interfering devices work together to minimize the problem), so the issue of legacy 802.11b signals won't be such a big deal.

More information here:
http://grouper.ieee.org/groups/802/15/pub/TG2.html

Repeat after me - Radio Data Rate!=Data Throughput

[pagley]

OK, it seems that there are a *lot* of people who either don't read the articles closely, or in the case of the last one posted on Slashdot, don't differentiate between "radio data rate" and "data throughput".

On ordinary 802.11b gear, the maximum "radio data rate" is 11Mbps. Once you account for the inherent loss in throughput because of the uncertainty of the medium (air), and the fact that the protocol was designed to accomodate this uncertainty, your actual maximum "data thoughput" is about half of that - around 5Mbps. 11Mbps 802.11b != 11Mbps throughput, it never has, it never will.

The same goes for 802.11g - the maximum radio data rate was, and _still is_ 54Mbps. However, the throughput is again slightly less than half of that, in the 20Mbps range.

The reported "change" to 802.11g to "20Mbps" media frenzy stemmed almost entirely from simply clarifying that the actual "data throughput" was about 20Mpbs, *not* that the radio data rate had changed, been knocked down, whatever.

You get roughly 20Mbps "data throughput" in a pure 802.11g network - and again, similar to 802.11b, 54Mbps 802.11g != 54Mpbs throughput.

A 4x increase in throughput using 802.11g over 802.11b is nothing to complain about. Now, if we could get Atheros 802.11g drivers for Linux, I'd be a much happier camper :) Although I do hear rumblings about drivers possibly surfacing soon - fingers crossed.

Brad

Sometimes, you gotta say..

[chriso11]

OK, once again.

802.11a: 5.4GHz operating frequency, 54MBPS data rate. Uses OFDM modulation, similar to DSL and HDTV VSB.
Good things about a:
-more channels than at 2.4HGz=more users simulataneously
-less interference from bluetooth and microwaves
-more advanced modulation standard=more data in less BW.
Bad things about a:
-a lot harder to manufacture: you can't even use the common FR4 substrate. Testing is more of a pain
-the modulation standard requires higher quality (more linear) transmitters
-5.4GHz experiences more attenuation, so less range

802.11b: The old reliable: 2.4GHz operating frequency (the same as a P4!), with 11MBPS data rate. Uses CCK, which is a massaged QPSK modulation method
Good things about B:
-most commonly avaliable type
-WiFi certification for interoperatiblity
-can use lower cost ic and materials. Testing is easier.
-longer range than A with less power (better for laptops)
Bad things about B:
-lower data rate
-more 'congested' spectrum
-CCK is less effecient in spectrum usage
-less channels available

802.11b+: Almost nobody has it: TI's PBCC modulation that gives 22MBPS on normal B. PBCC is an optional capability for G.
Good things about B+:
-it is/was available earlier
-Was cheaper
-Pretty much B, only a $10 more expensive.
Bad things about B+:
-I bought it because I couldn't wait for G
-Nobody except TI made chips that support PBCC
-Really, think of it as G-, not B+

802.11g: Same frequency as b, same modulation as A
Good things about G:
-backwards compatable
-easier/cheaper to get more linear transmitters for 2.4GHz than 5.4GHz.
Bad Things about G:
-no WiFi interoperability certification yet