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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."
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.
Here is the link to IEEE
a l.html
http://standards.ieee.org/announcements/80211gfin
ENJOY
Victory is gained, not in knowing your opponents next move, but in preempting them.
I remember an article on slashdot a while back stating that they were considering reducing 802.11g's bandwidth to something in the range of 10 - 15Mbps. I guess this stamp of approval has discarded this?
IEEE approves wireless network specs
.11g and .11b operate at ranges of up to 300 feet.
.15.3 spec suitable for its target application: small consumer devices, many of which will be operating in the same environment in close proximity. It features quality of service, connection management, advanced power management modesâ"allowing long and QoS synchronized sleep modes, ad hoc and peer-to-peer topology support, mesh support and enhanced security.
By Patrick Mannion
EE Times
June 12, 2003 (11:59 a.m. EST)
MANHASSET, N.Y. â" The IEEE on Thursday (June 12) gave its stamp of approval to two new wireless local- and personal-area networking standards and two corresponding recommended practices. The move is expected to open the floodgates to product introductions and upgrades while ensuring interoperability between those products.
The most anticipated of the four are the IEEE 802.11g and 802.15.3 standards for WLAN and WPAN connectivity, respectively.
The newly approved 802.11g standard specifies data rates of up to 54 Mbits/s in the 2.45-GHz band. While 802.11g uses orthogonal frequency division multiplexing (OFDM), mandatory provisions have been made within the standard to make it inherently compatible with the well-established 802.11b standard at 11 Mbits/s, which uses complementary code keying (CCK) modulation. Both
The 802.15.3 standard for High Rate WPANs also operates in the 2.45-GHz band and at similar rates, from 11 to 55 Mbit/s, but is designed for shorter-range (1 to 50 meters), very-low-power operation. It also uses time division, multiple access (TDMA) protocol.
The use of TDMA makes the
While 802.11g products based on the draft standard are already available, products based on the new 802.15.3 standard are not expected to appear until 2004.
The two recommended practices approved today are for 802.15.2 and 802.11f. The first, 802.15.2, addresses the coexistence issue between WLANs and WPANs operating in the 2.45-GHz bands, such as Bluetooth, 802.15.3 WPANs and 802.11b and g WLANs.
The second, the 802.11f Inter Access Point Protocol, ensures interoperability between access points from multiple vendors, which primarily enables client roaming.
Bush is on fire and its not good for my lungs.
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.
It has been a draft. Many vendors have already been shipping products for quite a while, however.
now we are going to hear another wave of uninformed folks complaining about the supposed speed limitation of 24Mbps... heheh
:)
from the same site: also, here's his announcement on 802.11g's ratification today. anyway, great news.
Large print giveth, and the small print taketh away
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.
Happiness is like peeing yourself. Everybody can see it but only you can feel its warmth.
This story kind of explains the speed thing. The actual throughput speed has not changed at all since 802.11g first came out.
Happiness is like peeing yourself. Everybody can see it but only you can feel its warmth.
More information here:l
http://grouper.ieee.org/groups/802/15/pub/TG2.htm
Dammit! Last post got hosed somehow. Here: http://slashdot.org/article.pl?sid=03/05/22/221624 7&mode=thread&tid=137&tid=193
Bluetooth: 1Mbps
802.15.3: 11, 22, 33, 44, or 55 Mbps (5 selectable rates).
802.15.3 is the logical successor, if the backwards compatbility works. But really, what comes after Bluetooth is more up to the Bluetooth SIG, who owns the branding..etc.
They both focuse on low power, low cost. 802.15.3 should cost pennies to implement into a device.
Security is pretty high. You can trust your keyboard to this sort of WPN, and not worry about a guy in a truck stealing your passwords.
-malakai
-Malakai
A Dragon Lives in my Garage
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".
:) Although I do hear rumblings about drivers possibly surfacing soon - fingers crossed.
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
Brad
802.11g has a much better range than 802.11b. Read this (pdf). What you want is probably the charts on page 12 and 13. 802.11g offers significant improvements over 802.11b.
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
No, I don't trust in god. He'll have to pay up front, like everybody else.
For those that don't know- 802.3 ethernet made a minor change from DIX- they just changed the MAC header format, nothing big! [sarcasm]
DIX had a header layout of: [destination mac address][source mac address][frame type].... [crc]
where 802.3 has [dest mac addr][src mac addr][frame length]....[crc] ( combine with 802.2 and you don't need a type field, you have SAPs!)
Now both formats are compatible by mutually exclusive Length/type field values: Since the ethernet frames are limited to 1500 bytes, all Types have to be values greater than that.
In the future, I would want to not be isolated from my friends in the Space Station.
No, you didn't recently read that. What you read was that the real effective data rate over "g" is more like 20 Mbps, and that in a network with a lot of "b" devices it might be more like ten. The raw speed is still 54 Mbps, the real speed is less because of the signaling overhead. There is similar overhead in 802.11b, you only get about 5 Mbps, and if there are any Bluetooth devices around you'll get a lot less because of interference.