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Faster, Stronger 802.11b
stoney27 writes: "Looks like U.S. Robotics has doubled the speed of 802.11b plus increased the range. See link on MacCentral." You'll need upgraded equipment at both the base-station and computer ends to get a boost in speed, but they claim compatibility with standard 802.11b.
Double the bandwidth! Does that mean I have to use two pringle cans as antennas? Once I pop, the file transfers don't stop!
I design user interfaces for a free network management application,
This *was* on /. just a few days ago.
2 13 &mode=thread
http://slashdot.org/article.pl?sid=02/04/20/149
It's still cool, though you only get the speed boost if both the transmitter and receiver are USR.
... when you post all your stories twice.
my other sig is a 500 page novel
Of course. We've just doubled the bandwidth, now we can read all Slashdot stories twice.
So we poor .EU people (where 802.11a is not allowed as the 5.4 GHz band is not free) can get a speed bump as well? I only wonder at what range the 22Mbps will work? 50m? 25m?
802.11g (Score:4, Interesting)
.11b APs will.
by cyr on Saturday April 20, @12:13PM (#3379398)
(User #571397 Info | http://a26.lambo.student.liu.se/)
A nearly free 100% speed boost is nice, but I would wait for 802.11g instead, giving 54Mbps in the 2.4GHz band and also being backward compatible with 802.11b.
I'm not an expert, but it seems to me 802.11a is doomed. Is there any reason to prefer it over the upcoming 54Mbps 2.4GHz stuff?
[ Reply to This | Parent ]
A couple reasons to choose 802.11a over 802.11g (Score:5, Informative)
by Freeptop on Saturday April 20, @01:35PM (#3379691)
(User #123103 Info)
First, the 2.4 GHz has a ton of other devices sharing the same spectrum, from Bluetooth to wireless headphones, to your microwave. 802.11a runs in the 5GHz band instead.
Second, according to the last proposals I'd heard of, 802.11g is going to achieve higher bandwidth by taking up more of the spectrum. In other words, it is going to use more channels to simultaneously broadcast data, rather than just being able to shove more data down the same channel. This means your own access points will begin to interfere with each other much sooner than your 802.11a or
In general, it is going to depend on your situation as to which you wish to choose. 802.11g will be great for backwards compatibility, but the news coming out of IEEE seems to indicate that 54Mbps is more like something to shoot for than something they expect to achieve. 802.11a won't have compatibility, and it will also have a shorter range, but it will have higher speeds with less interference.
Who run Barter Town?
U.S. Robotics, in doubling the speed of 802.11 by x2, has also succeeded in upsetting users of competing 802.11Flex modems.
More to come.
Nice! Now I can war drive at twice the speed!
These chips double 802.11b speeds by functioning full duplex. The drawback however, is that this requires category 5 air.
;)
Not all offices and homes fulfill this requirement. Location plays an important role: in the city you'll most likely not be able to communicate full duplex. In suburbs you'll have a fair chance if you're not too close to the city. In rural area's you'll most probably always have full duplex.
You can communicate at 22 Mbps over short distances using category 4 air, but when the peers are more than a few meters apart, category 5 air becomes a must.
Just something you might want to know before you buy these things..
Note: since this story seems a duplicate, I'll just duplicate my reply as well..
First, the 2.4 GHz has a ton of other devices sharing the same spectrum, from Bluetooth to wireless headphones, to your microwave. 802.11a runs in the 5GHz band instead.
.11b APs will.
Second, according to the last proposals I'd heard of, 802.11g is going to achieve higher bandwidth by taking up more of the spectrum. In other words, it is going to use more channels to simultaneously broadcast data, rather than just being able to shove more data down the same channel. This means your own access points will begin to interfere with each other much sooner than your 802.11a or
In general, it is going to depend on your situation as to which you wish to choose. 802.11g will be great for backwards compatibility, but the news coming out of IEEE seems to indicate that 54Mbps is more like something to shoot for than something they expect to achieve. 802.11a won't have compatibility, and it will also have a shorter range, but it will have higher speeds with less interference.
11 Mbps to 22 Mbps SOUNDS like a 100% increase, but what is the real speed/range gain? Given an 11 Mbps system with 3 nodes each at 10m from the access point, what is the actual thruput? Is switching to the USR system going to actually DOUBLE that?
Network speeds rank right up there with CRT sizes, CD-ROM spin speeds and tape storage capacity as some of the biggest bullshit numbers in computing.
...else you'd get a +1 Funny.
Got time? Spend some of it coding or testing
All of the 22Mbps 802.11 hardware coming out is based on the Texas Instruments ACX100 chip. TI was proffering this (their own) standard to become 802.11g, but lost out in the end. The chip is indeed fully backwards compatible with 802.11b.
There are going to be others putting out HW based on the ACX100 as well, Linksys for one. So well see how many people jump on the the bandwagon before 802.llg gets into the market.
The operating range for HW based on this chip will be larger. This is because the device can get a full 11Mbps signal with a signal to noise ratio half that of current HW. This means that at 11Mbps the range will be significantly larger. However at 22Mbps the range should be about the same as, perhaps slightly better than, current 802.11b systems.
The system uses the same channels as 802.11b and AFAIK doesn't use up more channels than 802.11b (ie 3 orthogonal channels in the US).
The chip is also all CMOS so power consumption should be somewhat better than todays 802.11 stuff as well.
That's all I know, hope this illuminates the issue...
Since this whole article/discussion is irrelevant anyway, let's all take a look at yahoo's great pic of the day, for some unintentional humor instead.
Shutting down free speech with violence isn't fighting fascism. It IS fascism!
It seems to be at least 24km, large-Milo(r)-tin-to-half-omni, provided that the half-omni is in Perth's Hills area and the Milo(r) tin has clear LOS to it from the flat bit.
Got time? Spend some of it coding or testing
Oh, you saw the spin-CDs-to-destruction report as well? The one where CDs would consistently explode before getting to true 64x?
Got time? Spend some of it coding or testing
They have a chance at this being successfull IF other companies use the same TI (Texas Instruments) chipset that USR is using. Otherwise - the doubling of speed will ONLY work with USR products that use the TI chipset - meaning your still stuck on 802.11b. (And paid extra money to do so)
We can rebuild it. Faster. Stronger. Geekier.
Anyone want to loan me a few million?
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Does that mean that I now only have to sniff packets for half the time in order to decode the WEP keys?
11g is really 11a-style OFDM at 2.4 Ghz rather than the 5 Ghz band. There would be two (at least) 11g modes: a compatibility mode whereby OFDM packets and legacy 11b CCK packets coexist, and one which is "pure" OFDM at 2.4 Ghz.
... and these differences are quite small if you have a good 11a radio with a good antenna.
The compatibility mode adds a huge overhead to each transmitted packet. An 11g transmitter in this mode must first complete a legacy 11b RTS/CTS operation on the air which, if successful, is followed by the actual packet. Even if the actual packet were transmitted at nearly infinite bandwidth, the effective bandwidth you'd see on a connection would be quite low - think 10 Mb/s on average. That's not exactly chopped liver and its way better than legacy 11b, but it's definitely not 54 Mb/s.
There are suprisingly large differences between 11a products, even those using the exact same vlsi chips. There are two primary reasons: differences in choice of output power amplifier (or lack thereof) and differences in choice of antenna. You can deduce some of what's going on by looking at power and sensitivity ratings in manufacturers product specs. By the way, this also a great way to distinguish between 11b products as well.
Second generation 11a products have much better receiver sensitivity and output power than the first generation versions. And they do transmit through walls... although not concrete or metal or mirrors or some ceramics.
The main reason why 11b can reach farther than 11a in some situations is that 11b can ratchet down to 1 Mb/s whereas 11a is defined for rates from 54 down to 6 Mb/s (11g is identical to 11a in this regard). The difference in SNR and sensitivity needed at a receiver to pick out the 11a or 11g signal accounts for nearly all of the differences in range
Thus, 11g will have the same power, SNR, and receiver sensitivity challenges as 11a in the 5 Ghz band, but will also have a small boost in signal propagation efficiency in the lower band.
Don't get bamboozled by the hype about compatibility with 11b. Compatibility for sharing the channel does not imply that the radio properties of 11g are the same as 11b.
Most vendors are busy bringing out 11a+b base stations and NIC cards. 11g in compatibility mode looks like a nightmare, whereas 11g in "pure" mode looks like 3 more channels of high performance OFDM if you have an 11a radio that can tune to both the 5Ghz and 2.4 Ghz bands. Aside from the higher-power outdoor channels at 5.8, this provides 11 channels for OFDM (8 at 5 Ghz plus 3). And this means that a group of base stations in an AP-dense environment will certainly be able to find a clear channel.
I didn't say much about the PBCC-based 22 Mb/s products. PBCC is actually a clever design but is likely going to be overshadowed by OFDM at 5 Ghz (11a) and OFDM at 2.4 Ghz (11g variants).
11 mbps is fast enough thank you but if you're going to double something then double the SNR and effective max range instead.
15 minutes ago, I brought home a new Zyxel 316 Wireless starter kit. I just figured I check slashdot before I configured it, and now its obsolete. Great.
TI has been pushing the PBCC modulation scheme for years. Recently, PBCC was dumped from the 802.11g spec, so now TI is trying to do an end run around the spec, and making it a done deal.
The OFDM method used in 802.11g and 802.11a is more elegant, and provides a higher data rate than the PBCC. Of course, in fairness, Intersil is pushing for OFDM.
Bottom line: if 802.11g isn't out soon, TI will be in a good position to put PBCC back into 802.11g by market pressure. The catch - 802.11g will be slightly (maybe $20) to support this lower performance mode.
No, I don't trust in god. He'll have to pay up front, like everybody else.
Apparently true, as in, leaves gouges in 1mm sheetmetal, and CD drives aren't made that tough.
Got time? Spend some of it coding or testing