Use Multiple Channels for Faster Wireless Networking

icypyr0 writes "The Register reports: 'Current dual-mode 802.11 'a' and 'b' access points use only one of Wi-Fi's 11 RF channels at a time, with users taking turns. The Engim chipset can 'see' all 11 at once, and can use the three non-overlapping ones (1, 6 and 11) in parallel, increasing total throughput and enabling features to be incorporated in silicon that are usually implemented, at extra cost and performance degradation, in software.'"

Comments

Range is fine but...

[Cyno01]

Unfortunately the neighbors decided to microwave a burrito and their throughput went all to hell.

Re:Range is fine but...

[swordboy]

Unfortunately the neighbors decided to microwave a burrito and their throughput went all to hell.

Who needs a microwave when you can just stick the burrito in the access point's line-of-sight?

I suppose that could possibly affect throughput as well...

Re:Range is fine but...

[jedrek]

Man... I wish we could get microwave burritos here in Poland.

Mmm... waveolicious.

Re:Range is fine but...

[Illbay]

Reminds me of the old "space race era" joke about Poland announcing that while the U.S.S.R. and U.S.A. were vying to put a man on the moon, the Poles were sending a man to the sun.

When asked how they planned to have him survive the incredible heat, the response was "we're going to do it at night!"

Re:Range is fine but...

[_avs_007]

If your microwave "leaks" that much radiation, you have bigger problems to worry about than through-put ;)

Polish

[Crash42]

Well, my polish is not that good (except my RPN/RPL) so i'll take your word for it....

Re:Polish

[Illbay]

Man, I wish we could get RPN calculators here in Poland!

Old joke to be duped

[heir2chaos]

How many pollocks did it take to acheive this?

Re:Old joke to be duped

[Sherloqq]

In this case, five :)

# Piotr Kroplewski - owner of INTERLINE, who supplied the antennae
# Wieslaw Karpowicz - production manager
# Maciej Kaminski - director of technology dept.
# Krzysztof Mularczyk - wireless networks expert
# Krzysztof Juszczyszyn - tech dept.

Comment removed

[account_deleted]

Comment removed based on user account deletion

110 Km?

[JRHelgeson]

WOW! 110 Kilometers! What is that, like 500 feet?

Re:110 Km?

[grokster]

How big are your feet?

Re:110 Km?

[Crash42]

it's about 70 miles.

Re:110 Km?

[dcordeiro]

FYI,
google calculator says its something like:
110 kilometers = 68.3508311 miles

Re:110 Km?

[Anonymous Coward]

i remember you, you're that engineer who programmed that polar Mars probe aren't you?

Re:110 Km?

[JRHelgeson]

[WOW! 110 Kilometers! What is that, like 500 feet?]

I cannot believe the number of people who modded this parent up, then back down... All I'm saying is that most Americans have no concept of a kolometer, or a liter. We think in miles & gallons.

It's an obvious joke people! Laugh!

Err... it is a cheat

[arivanov]

Err... My polish is crap, but unless I am mistaken they seem to have used a 500mW aplifier and a 27dbM antenna to boot.

What's next? Sticking it in the middle of Aresibo and claiming half a light year range?

Re:Err... it is a cheat

[Zocalo]

What's next? Sticking it in the middle of Aresibo and claiming half a light year range?

Pshaw! Who needs Arecibo? *My* crappy off-the-shelf 802.11b card can get *infinite* range un-aided! True, picking the signal out from the noise at more than 50ft is proving problematic at present, but once I've ironed out that minor problem I'm well on my way to PROFIT!!!

Or was I the only person paying attention in physics when it was explained how *any* electromagnetic transmission has infinite range, since decaying amplitude in accordance with the inverse square rule never reaches zero? Assuming a perfect vacuum, naturally.

Re:Err... it is a cheat

[tundog]

Assuming a perfect vacuum, naturally

You forgot about the frictionless pond!

Re:Err... it is a cheat

[gato_mato]

Errr - That is ARECIBO - Don't misspell my home town man

Gato

Re:Err... it is a cheat

[mgg4]

Or was I the only person paying attention in physics when it was explained how *any* electromagnetic transmission has infinite range, since decaying amplitude in accordance with the inverse square rule never reaches zero? Assuming a perfect vacuum, naturally.

Actually there is a difference between the unlimited range you claim, and the usable range of your devices. As you also pointed out, the background noise, caused by all those other signals with unlimited range, is going to get in the way of your PROFIT!! But hey, I hope you figure it out.

Re:Err... it is a cheat

[11011001]

can you imagine the ping rate in your favorite multiplayer game?? man...

Re:Err... it is a cheat

[Via_Patrino]

They just putted the antenna so high to avoid earth curvature problems and bought an amplifier not avaible to the general public.
Don't see a lot of inovations here, but props for them doing that if it was with that fog in the pictures.

Hrmm

[acehole]

I guess using two pringles cans instead of two really did the trick.

Damn measurement standards..!!

[Anonymous Coward]

110kms??? What's that in freight trains?

or how many of the sears tower layed on it's side?

Re:Damn measurement standards..!!

[The Grassy Knoll]

Never mind freight trains, how many times the size of Wales is that?

Re:Damn measurement standards..!!

[RabidMonkey]

Sears tower = 442m
Boxcar = 43 feet avg (http://www.railwaystation.com/1942/05.html)
Avg freight train length=45 cars
Avg lenght in feet = 1935 feet

google tells me theres

Re:Damn measurement standards..!!

[RabidMonkey]

DAMMIT!

apparently pressing ctrl-enter submits ... same as how I submit tickets .. stupid habits die hard.

lets continue that.

Sears tower = 442m
so we have 248.8688 sears towers

Boxcar = 43 feet avg (source)
Avg freight train length=45 cars (some other site that won't load but is cached)
Avg lenght in feet = 1935 feet

google tells me theres 0.3048 metres in a foot so we have the avg freight train being 589.788m long.

That means we have 186.5077 freight trains (not counting engines) end to end


length of football field (cdn) = 100m
length of football field (us) = 109.1m (source

That leaves us with 1,100 cdn football fields, or 1008.2493 american fields.

a us dollar bill is 156mm long (source
so that gives us 705128.2051 dollar bills, end to end

asian elephants can grow to 340cm (3.4m) (source)
so thats 32352.9412 elephants

I think thats good enough for now. back to work.

Re:Damn measurement standards..!!

[The Mayor]

When comparing football fields, it's imortant to compare apples to apples. The length of the Canadian football field is 110 yards (which, although close, is not 100m). The endzones on a Canadian football field are 20 yards deep (each). An American football field is 100 yards in length. The endzones are each 10 yards deep.

Despite the erroneous quote you found that compared the length of one field to another, the relative lengths of the fields are either 110 yds vs. 100 yds (Canadian vs. American using just the playing field) or 150 yds vs. 120 yds (Canadian vs. American using the playing filed plus the end zones).

Huzaa!

[rf600r]

Maybe there's hope for me getting a signal down the hall?

Naaaahhhhh.......

Re:Huzaa!

[Anonymous Coward]

Nope, no hope. I've setup about four dozen wireless Ethernet networks for the ISP I work for, and not a one of them works worth a damn. Well, there is one that covers only one room that works 100%, but other than that, 802.11 is complete crap. You can often get it to work for a few minutes, like these guys have, but long-term, you have non-stop problems. Even with 24 dBi antennas on each end and 100mW transmitters, the main wireless connection at the ISP I work for still doesn't work worth a damn going just across a wide street. We're using it since it's taking Hell$outh, err BellSouth, 18 months and counting to move our T1 to Sprint.

I wish a company would start making wireless that works. Instead, the marketers rule and keep pushing for bigger numbers on the boxes. Who cares if it's 5.5, 11, or 55 Mbps if it doesn't work at all?

Re:Huzaa!

[sketerpot]

I wonder if this could be useful for, say, Armadillo Aerospace. I think that they're using 802.11b at the minimum bandwidth with a 1 watt transmitter for their remote control on flights. Perhaps something like this could increase reliability.

Re:Huzaa!

[BawbBitchen]

You do not know what you are doing then. I have a link that is 3km running 802.11b with Smartbridges and 14 dBi backfires that is rock solid. I also have a few 8+km links using 5.3/5.8. Oh, I have 28 other 802.11b networks that are rock solid and have been running over a year.

that's 110 kilometers...

[192939495969798999]

or 66 miles for the math impaired (sigh). Still, that's rad! You could access that across the English channel!

Re:that's 110 kilometers...

[zerocool^]

I don't know about across the english channel. At some point, you pass the horizon, where you can't go any further due to the curvature of the earth. I was pretty sure that level was around ... either 50 or 100 miles, I don't remember. Can you see France from Kent?

~Will

Re:that's 110 kilometers...

[Rosco P. Coltrane]

You could access that across the English channel!

Yes, and just imagine the improvement when they finally dig the 802.11b tunnel!

Re:that's 110 kilometers...

[chrestomanci]

Can you see France from Kent?

You can, though it is easier to see Kent from france, as the white cliffs of dover stand out quite well.

BTW, it is about 20 miles, (across the straights of dover) and there are tall cliffs on both sides, which improves sight lines

Re:that's 110 kilometers...

[Cpyder]

I don't know about Kent, but on a clear day you can see the rocks of Dover just fine from Cap Griz Nez.

Re:that's 110 kilometers...

[akadruid]

I don't know about across the english channel
Damn straight you don't!
Distance will not be a problem - at only 21 miles (34 km) across at the narrowest point, weather permitting, you can clearly see 'Le Francais' from the White Cliffs of Dover.
you can't go any further due to the curvature of the earth
WTF? Surely you can't see any further! Actually you're miles out here too.
The distance (in km) of the horizon on earth, on a plain, is approximately s(13h) where h is the height (in metres) of the eyes multiplied by the 13, and s is the square root symbol slashcode can't cope with.
Were you to mount an antenna on the beach, you would find that the horizan at around 5km away would be a big problem.
Stick it up on said White Cliffs of Dover, at 250m above sea level, and you will have no problems with line of sight.
The only barrier to this idea is the regulations governing the area.
Sources: Channel, Cliffs, Horizan

Re:that's 110 kilometers...

[Wanderer2]

Never misunderestimate the bandwidth of a Euro-Star full of hard disks ;)

Re:that's 110 kilometers...

[zerocool^]

heh, thanks for setting me straight. That's really interesting, to think that you could have wireless across the channel, although, with the exception of the ocean, I guess it's not too much different than sending a signal from france to spain.

Re:that's 110 kilometers...

[zindorsky]

At some point, you pass the horizon, where you can't go any further due to the curvature of the earth

The earth is flat, sinner.

Re:that's 110 kilometers...

[mgg4]

The distance to the horizon can be calculated using the formula:

D = 1.17 * sqrt(h)

where "D" is the Distance to the horizon (in nautical miles); and
"h" is the height of the observer (or antenna) in feet.

To find the distance you can communicate over the earth using line-of-sight communications (like 2.4 GHz is), you need to do the DTH (Distance to Horizon) calculations for each antenna, and then add them together. This gives you the total distance.

To get the required 110 km, you would need two antennas about 650 feet (200 meters) tall.

Re:that's 110 kilometers...

[akadruid]

As with everywhere else, the technology is no the limiting factor here, but the regulations. It would not be possible under current UK law to mount the transmitter this side of the Channel. I'm not sure about France - you may have more luck there. I the South-East of England, you cannot receieve on of our terrestial channels due to French interferance in that area. Not that anyone watches Channel 5 anywhere else anywy.

Opps

[acehole]

I meant...

I guess using two pringles cans instead of one really did the trick.

Geek factor 9.3 useful factor 1

[obi1one]

(error 1337 destination page /.ed) Is increasing the range of current wireless networking equipment really what is needed. I know i personally am turned off from wireless not because of the lack of range, but the lack of speed. There is certainly some cool factor being able to get that masssive a distance, but I dont see this as making wireless more desirable to anyone.

Re:Geek factor 9.3 useful factor 1

[FatAlb3rt]

802.11g claims 54Mbps - how much faster do you need? hell, 11b is 11Mbps. that's still faster than most people's internet access.

the speed is where it needs to be (for now). i am very interested in getting a signal that doesn't crap out when i go to the other side of the house.

anyone got a link for a comparison of AP brands vs. range? comments on the linksys signal booster?

Re:Geek factor 9.3 useful factor 1

[BigBir3d]

802.11g claims 54Mbps

"802.11g is still a 54Mbit/sec standard," Bell told MacCentral. "802.11b is 11Mbit/sec, but your actual throughput is somewhere between 4 and 5-1/2Mbit/sec. The number that's quoted is the data rate that's used between the radios (raw data rate, which includes the protocols etc.)"

Although internal tests have shown slightly higher data rates, the actual data rate for 802.11g will be approximately 20Mbit/sec, which is 4 to 5 times higher than 802.11b. Bell said the data rate has always been around 20Mbit/sec and hasn't changed in the final draft standard.

source

Re:Geek factor 9.3 useful factor 1

[RhettLivingston]

Not only do they not typically reach more than half those speeds in actual throughput, but 802.11g reverts all of its users to 11b speeds in the presence of any 11b client and that is a shared bandwidth. I live in condominiums and my 11b gets so much interference that my connection is lost from 10 feet away about once every 3 minutes (multiple stations and client cards, same problem, so not a hardware issue). And since the bandwidth is shared, there really is no possibility of creating home multimedia networks with this. So, one of the biggest hopes, that it can eliminate the need for wiring home devices that are not mobile, is really hopeless with this standard.

Re:Geek factor 9.3 useful factor 1

[dustinmarc]

I'm not sure what type of network your on, but where I work we have regular 10Mbps Ethernet. Where I go to school, they use 802.11b. I don't ever notice a difference in speed. Chances are most users won't either, because the bottleneck isn't your access medium if your primary use is internet access. I suppose for traffic in your intranet that you'll see the difference but I think that this type of usage in networks these days is relatively low compared to internet traffic. I, for one, love wi-fi. Without it I wouldn't be able to post to Slashdot while sitting through a boring three hour lecture.

Re:Geek factor 9.3 useful factor 1

[skamp]

802.11g claims 54Mbps - how much faster do you need?

As stated by BigBir3d, 802.11b actually provides aroung 4-5 Mbps, and 802.11g around 20 Mbps. The thing is, Wi-Fi is not a replacement for fast ethernet yet. If I appreciate hard drives providing ever more bandwidth, it's because I like to transfer large files over my LAN quickly. I can't do that over Wi-Fi. So, to answer your question, I need as much bandwidth from a wireless setup as my hard drives provide.

Re:Geek factor 9.3 useful factor 1

[_avs_007]

I work with a lot of wireless APs and client cards in our lab.

If you are talking about G type stuff, stay away from Linksys, they have the crappiest range. When I used it in my house, I would get 68db with an Intel 802.11b AP, but the Linksys G router/AP yielded 77db, and that was only going through 2 walls.

I replaced it with a Netgear WGR614, which uses the Intersil Prism GT chipset (as does the D-Link we tested), and got much better range. Similar to straight B. ~68 or 69 db in my master bedroom.

In our office environment, the Linsys G would drop signal after walking past the conference rooms. The Netgear G allowed us to almost walk around the entire floor. I connected a signal booster, and found it to be next to worthless, as it did not improve range. If it did, only by 5 ft or so. It still dropped signal as I walked past the conference rooms.

The measured actual throughput was 4.5mb/s with straight 802.11b, and 21mb/s with the Netgear G.

Quite suprisingly, I had the best results with the Netgear WAB102 Dualband A/B, which is the only A/B AP that uses Atheros second generation A. Tom's Hardware had a write-up on this. Atheros had a whitepaper. I bought 3 of these, and verified the claims.

With a Linksys A+G card, (which uses Atheros 5001X+, as does Netgear WAG511), I got slightly weaker signal strength in my master bedroom 70db), but throughput killed both B and G. I was measuring 24mb/sec throughput in non-turbo mode, and 45mb/sec in turbo mode. In the office, I was able to sustain 7-11mb/sec at the opposite end of the building. The Netgear G was only able to sustain 1-2mb/s. Inside the conf rooms, Linksys G had no signal, Netgear G sustained 7mb/sec, Netgear A in turbo mode sustained 24mb/sec.

In the office, the range of this second generation A actually exceeded that of B, which is something Atheros pointed out in their whitepaper. They said while true A can't go through walls as well as B, the 1st generation A was not performing up to its capabilities. Kind of like how Shannon's law states what is the maximum amount of data that can be carried across wireless, but current technology does not even begin to approach this limit.

I've tested various client cards from Orinoco, to Cisco Aeronet, Prism 2 and Prism 3 cards, and various Atheros based cards. I that the AP affected range more often than the client cards. Though I have found that anything based on the Atmel chipset to be crap. The USB 802.11 card from Linksys (V2.6) uses this chipset. Unfortunately, the Netgear WAB102, uses Atmel for its B, so its B is crap as well. I just use the A portion of it anyways. But the new Netgear triband router, I beleive uses Atheros for all three bands, it just costs an arm and a leg.

The Linksys Triband AP, only uses Atheros for the A, it uses Broadcom for B and G, so its G sucks just like the Linksys B/G stuff.

Somewhere I also read that Linksys will not support any turbo modes in their AP/Routers. (though their A+G client card still supports turbo). Both Atheros and Intersil have planned turbo features. Atheros already had 108mb/s A support in turbo, allowing 45mb/sec throughput by using multiple channels. They already have support for hardware compression, so are promissing a future firmware update that will flip this on, that will allow a turbo mode to sustain 90mb/sec throughput. Its called SuperA. They just released SuperG, which uses multiple B/G channels and compression, to allow 108mb/sec, and I think 45-60mb/sec throughput.

Intersil's turbo technology is called Nitro. Similar (but incompatible) with Atheros's technology.

They stole his idea...

[tbase]

Hey - that antenna they're using looks a lot like the one from this story. Of course, he only claims a LOS range of 10 Miles.

Faraway, But So Close?

[ausoleil]

I for one find it ironic that someone can detect and possibly decode my WiFi signal from roughly 70 miles (per the new world WiFi record) but I can't get a useable signal on my laptop three rooms away from the WAP.

First time I've seen this happen...

[JRHelgeson]

We /. the site, and it's not even in english. Who's going to RTFA when it's in polish?

Anyone got a Polish->English translator?

I checked Google, Babblefish & Dictionary.com with no luck.

Re:First time I've seen this happen...

[Sherloqq]

see "Some details" further down.
I didn't translate, but I summarized the most important bits.

Here's the equipment they used (which I didn't include in my other post):

# Antennae - Interline PARABOLIC maxi, 27 dBi
# Access Points - INTEL Pro/Wireless 2011 Access Point, made by SYBMOL
# Cables and connectors - BELDEN H-1000, H-155, RG-316, VITELEC connectors
# Wireless cards - Lucent ORiNOCO PC Card Silver/chipset Agere, ZCom XI-300/chipset Intersil
# Amplifier - 2.4 GHz, 500 mW

Re:First time I've seen this happen...

[Anonymous Coward]

Mirror here It's at uni, so I've no idea how long it will last...

Re:First time I've seen this happen...

[zentigger]

It belongs to underline, that ground was realized link in distinguishing from link realized (accomplished) from stratospheric balloon in sweden by firms 2002 year typically ( near the end Alvarion and appoint important ) that plane Swedish Space Corporation, they are used all elements in experiment of firm on market unmodified available ( parabola 1.1 meter (subway) INTERLINE urzdzeniami/osprztem and consolidator 500 ) mW - but it use parabolic antenna in sweden about 2.4 meter (subway) rednicy and consolidator 6000mW. Two ultra localizations appoint on requirements of experiments wroclaw and room (shop) under snow white - highest up above Karkonoszy on midday (southern) east from yelenya gora -.

OK, here's a translation. It doesn't make a whole lotta sense to me, but I'm a bit curious about a couple of things. What's with the bit about a "stratospheric balloon" and what were they using at 6000mW?

Re:First time I've seen this happen...

[emoui]

You may try at www.ectaco.com, but there is only word-by-word or simple sentences translation.

Re:First time I've seen this happen...

[Sherloqq]

OK, here's a slightly better translation (my own):

"It needs to be stressed that the link created here was a typical ground-based connection, as opposed to the link created at the end of 2002 in Sweden which used a stratospheric baloon"

For details of that accomplishment, go here (this link was posted already in this thread here by wherley).

Essentially, the Swedish ground-to-air link was aided by a 6Watt amp and achieved a distance of over 300km. In comparison, the Polish link was ground-to-ground (i.e. subject to much more interference, be it EMI or air pollution), reached about 1/3rd of the distance while using 1/12th the power.

Re:First time I've seen this happen...

[zentigger]

Ahhh, that makes a whole lot more sense :)

Wow 110 kilometers

[Zakabog]

I wonder how many pringles cans that took.

Re:Wow 110 kilometers

[Inflatable Hippo]

> I wonder how many pringles cans that took.

275,000

They connected them end to end in an unbroken chain between the base station and client.

Re:Wow 110 kilometers

[EnVisiCrypt]

I know you're joking, but assuming that a pringles can is 9.25in tall (the best figure I could find), it would take 450,082 end to end to reach that distance. :)

Re:Wow 110 kilometers

[Inflatable Hippo]

> I know you're joking, but assuming that a
> pringles can is 9.25in tall (the best figure I
> could find), it would take 450,082 end to end
> to reach that distance. :)

Pringles cans are bigger when measured in cm.

For those who don't understand Polish

[miodekk]

The folks used devices that are freely available on the market (WiFi or WLAN PCMCIA cards, amplifier, antennas, etc), chosen locations within the range of about 66 miles (110 km) with visibility (to achieve this you must see the other point).
So this is a relatively cheap method to get Internet access in distant locations, specifically in mountains, where it is difficult to get a wire.

Regards

Some details...

[Sherloqq]

The article claims the experiment used off-the-shelf, commercially available, unmodified components (1.1m / 3.5ft parabolic antenna and a 500mW amplifier). Experiment was conducted in a mountainous region in southwestern Poland.

So this isn't all that bad... considering the average laptop wireless card puts out, what, 20mW? 50mW? using a 500mW amp to achieve a much greater distance is pretty sweet. By comparison, the article quotes a Swedish experiment which used stratospheric baloons and a 6W amp, but they don't mention the distance achieved.

Mind you, rules about how much power certain appliances / transmitters can put out with or without a permit vary across the globe, and I'm not sure whether 500mW is legal for private unlicensed use in Poland or not. But if it is, more power to them.

Now, where can I get mine?? :)

Re:Some details...

[Sherloqq]

Few more notes...

Initially they didn't use an amp, and were getting 20% thruput, which allowed for a 1Mbps link to be established. That link kept going down every few seconds, tho, so they put in the amp. This boosted their RSS readings from 8 to 28, which meant 80% thruput. Having reached that, they tried to ftp a file and although they don't say how big it was, it was copied over at 40kBps, or around 0.5Mbps.

I don't know about you, but seeing ping replies in the single digits and low teens while ~70miles away makes my spine tingle.

Re:Some details...

[afidel]

Typical cards have a max transmit power of 50mW and the good ones (like Cisco's) have a max of 100mW. I'm not sure if Poland's entry into the EU means that they fall under ETSI regulations, but if it does this most certainly was NOT legal as the ETSI standard limits transmit on cards to 50mW and point to point links are even more limited to than the US (which is 24dBi gain on a 100mW card).

Re:Some details...

[jrockway]

Sorry, your notation confused me. The file transferred at 40KiB/s. That's 0.5Mbps or about half-T1. I get it :)

Re:Some details...

[Garak]

You can get 200mW cards off the shelf aswell!

Check out seattle wireless's website and look at the hardware comparision.

Re:Some details...

[ryanvm]

I don't know about you, but seeing ping replies in the single digits and low teens while ~70miles away makes my spine tingle.

Uh, that tingling is the 500mw microwave signal cooking your spine.

Re:Some details...

[Moskit]

Mind you, rules about how much power certain appliances / transmitters can put out with or without a permit vary across the globe, and I'm not sure whether 500mW is legal for private unlicensed use in Poland or not.

I don't think so. Legal limit for unlicensed 2.4GHz is 20dB EIRP. As they've used 27dBi antenna, it's already way out of the spec, not to mention 500mW amp (another 27dBm).

110kms? The world record is already 310km.

[wherley]

Here
is the story from July of an outfit getting 310km using WiFi from ground to a balloon. This was done by Alvarion and the Swedish Space Corporation and acknowledged by Guinness (as in world records not as in beer).

Re:110kms? The world record is already 310km.

[Anti_Climax]

It may not be the world record, but more power too them, especially since they did it from two terrestrial points. With fog, dust, reflections off anything along the ground, I'm glad to see them break the 50 mile mark with readily available hardware.

So you know, Guinness of beer and guinness of World Recod were (are) one in the same. The Guinness Book began as reference to settle disputes common amongst drinkers and bar goers who insisted they knew about the biggest/best (insert random arguement starter here)...

Re:110kms? The world record is already 310km.

[legend]

Mod parent up. This one with the balloon is for real, and yes, it already holds the record.

Re:110kms? The world record is already 310km.

[miodekk]

> getting 310km using WiFi from ground to a balloon.

Yes. But for normal use ground to balloon connection isn't very usefull.
This time it was ground - ground connection. One point was on the mountain at the height of 1400 meters above sealevel, and the other in a distant city on a scyscraper.
Btw. 1400 meters is about 4600 feet.

Re:110kms? The world record is already 310km.

[akozakie]

So? They manetion it, and they don't claim a record range. What they have achieved ia a world record ground-to-ground wireless connection. OK, so they used a mountain, but it's still ground based.

Translating from the article, word by word (I'm not much of a translator):

"It has to be stressed, that the realised link was fully ground-based (unlike the link realised in 2002 using a stratospheric baloon in Sweden by the companies Alvarion and Swedish Space Corporation).

Also important is, that all elements used in the experiment of the INTERLINE company are unmodified hardware available on the market (parabolic antenna 1.1m and 500mW amplifier), while in Sweden a 2.4m parabolic antenna and 6000mW amplifier were used."

See? That's the difference. Maybe I should translate more of this for /., but I have to leave now. Oh, boy, so much karma, so close, and yet so far away...

Re:110kms? The world record is already 310km.

[austwireless]

72mile link that was mentioned earlier here still beats it for ground to ground by about 10km... Better luck next time kids :)

Re:110kms? The world record is already 310km.

[MikeHunt69]

acknowledged by Guinness (as in world records not as in beer).

The are actually the same company. (seriously)

Re:110kms? The world record is already 310km.

[akgunkel]

The are actually the same company. (seriously)

Um, I don't think so...

You are probably going on this quote from the GWR web site:
"In 1951, Sir Hugh Beaver, then the managing director of the Guinness Brewery, went on a shooting party and became involved in an argument. Which was the fastest game bird in Europe - the golden plover or the grouse? He realized then that a book supplying the answers to this sort of question might prove popular. He was right!"

However, their corporate page says this: "Guinness World Records is a division of HIT Entertainment."
(Guinnes World Records) HIT Entertainment also happens to be the wonderful people who bring the world's children "Bob the Builder, Barney, Thomas & Friends, Kipper and Angelina Ballerina" via "programme sales to 150 countries and territories".

While the other Guinness seems to be currently owned by these folks.

Re:110kms? The world record is already 310km.

[c4seyj0nes]

You're both half right. Guinness doesn't own the book , but they were the origional creators of it (actually their owner, Sir Hugh Beaver, came up with the idea and contracted a fact-finding agency to make it for him). As someone mentioned above the book was used to settle bar disputes. So no its not really Guinness' Book, just the owners idea, and it has their name.

Satellite dishes

[Rosco P. Coltrane]

Good thing they did that in Poland. If they had tried this in the US, they'd have been sued by DirecTV for hacking a satellite TV system and the RIAA for trying to set up a P2P link. Of course, none of this would matter since they'd all be in a 3x2 federal pen cell awaiting for months to be charged with setting up a data link that could be used for terrorism ...

Re:Satellite dishes

[smithmc]

since they'd all be in a 3x2 federal pen cell

Now, now. You know you're not supposed to make a reference on Slashdot to the Federal corrections system without calling it "Federal pound-me-in-the-ass prison".

Amateur radio operators do more than this...

[josecanuc]

105 km is a good ways off. But Amateur Radio operators have been getting better than this with their voice transmissions (and possibly digital) on frequencies from 50 MHz to 10 GHz at the 2003 September VHF QSO Party.

See some of their setups at http://www.arrl.org/contests/soapbox/?con_id=53.

Our university station was making contacts on frequencies greater than 2.4 GHz for distances longer than 200 miles. Contrary to common sense, Line-of-Sight is not necessarily required to get microwave transmissions to work over long distances. But they're very weak ;-)

Some more details

[miodekk]

They have achieved a steady transfer of about 40KB/s (40 kilobytes/second) using normal FTP.
The negotiated bandwidth was 1Mb/s.
And the weather conditions were far from perfect :-)

Regards

ground attenuation...

[AmigaAvenger]

The article already is almost dead... Can't check how they did it, BUT... the biggest problem isn't signal power, that part is easy with even a minimal amp and decent parabolic grid antenna. The tough part is the curvature of the earth. Beyond 10 miles or so, you have to get your antennas substantially off the ground, otherwise the amps and high gain antennas make absolutely no difference...

Re:ground attenuation...

[Kvasio]

According to the page, one of the antenas was on the roof of 10-storey building in Wroc?aw
(city is located in between 100 and 148 meters above sea level), and (as I believe - it's /.'ed now) the Sniezka mountain (which is 1602 meters above the sea level). Thus the antenas were substantially off the ground...

Re:ground attenuation...

[Sherloqq]

you have to get your antennas substantially off the ground ... which is what they did. One of the antennas was on top of a 10-story apartment building, the other was on the side of a mountain, 1400 meters above sea level (which is around 4800ft) with hardly anything in between (see map).

Re:ground attenuation...

[LucidityZero]

The tough part is the curvature of the earth.

Silly! That's why the expirement was done in Poland! The Earth is still flat out there!

Re:ground attenuation...

[yack0]

Well, it's not 'that' bad.

At 66 miles, a 60% Fresnel zone would be around 195'.
At 66 miles, the curvature of the earth would be about 160'.

Combined, for a 60% fresnel, you're looking at antenna heights (center of radiated power) at about 160 + 195 = 365 feet.

However, if the angle at which the 10 story building was 'looking' high enough up to the mountain top, they could have made it, but at 66 miles, I doubt it. There was no doubt some measure of reflection/refraction of the signal by terrestrial objects.

365' of height is not that hard to get past if you can find the right two mountains.

Now, to the Maine Atlas for me to find those two mountains! :)

I claim a *double* WiFi distance record

[Rosco P. Coltrane]

3603 miles, between me in Paris and my friend Bob in New-York:

My_laptop <-> my_AP <-> The_innurnet <-> Bob's_AP <-> Bob's_laptop

Re:I claim a *double* WiFi distance record

[Alien Being]

Not very secure though. Them Duke boys could be listening.

Re:WOW! THE DISTANCE!

[sharkey]

110 Kms

110 Kilometer seconds

Shouldn't that be Kelvin milliseconds?

This is a world record.

[termos]

or not?.

There isn't much to block a radio signal if you're in a balloon; so the news that Alvarion has managed to reach a 310 km distance probably isn't as exciting as it sounds.

and probably not legal

[RMH101]

from memory, there's a legal maximum to what you're allowed to broadcast wifi with without a licence. it'll be less than half a watt as well...

Re:and probably not legal

[afidel]

This would not be legal in the US based just on the antenna which is 27dBi, the max gain you can have with a 100mW card is 24dBi. In addition they used a 500mW linear amplifier which makes the output power many times more than the FCC allowed limit and probably creates all sorts of nasty noise on adjacent frequencies.

Re:and probably not legal

[div_2n]

Actually you can't use a 24db antenna with a 100mw card. The maximum EIRP allowed under the FCC for point to point is 8 watts (39db) and 4 watts for point to multipoint. If you use 100mw (20db) input into a 24db gain antenna, your total EIRP will be 44db or 25 watts. Not legal at all. Also not healthy to stand in front of the antenna for more than a few minutes.

Re:and probably not legal

[pcjunky]

You can run 1 watt into a 6dbi antenna. For point to point you need to reduce your transmitter power 1db for every 3db increase in antenna gain. This means the max antenna gain for 500mw would be 15dbi. Add 9db to the gain to get 24bdi and you need to drop power another 3db or 250mw. 100mw would be legal at 27dbi but not 500mw. Since you need to increase total gain 6dbi every time your double your distance this would make this shot easy with 27dbi antennas and 500mw amps. I have heard of 20 mile links using legal power levals/antennas. The 500mw amps make this easy. To do this legaly would require very high gain antennas perhaps more than 33dbi. This would be the max legal output for 125mw. Most really good radios put out 100mw. I imagine that a 8 foot dish feed with a biquad antenna might do it.

Re:and probably not legal

[ajberg]

FCC? Um it dosn't look like they did this in the us.

RTFA for the whole truth

[Sherloqq]

The weather balloon reached a maximum height of 29.7 km and drifted steadily. It finally touched down east of Sodankyla in the northern part of Finland, having travelled approximately 315 Km.

On the balloon, the BreezeNET DS.11 unit was connected to a high-power amplifier with 6 watts power output, a camera and a server.

Impressive though the achievement is, it has no bearing on how WiFi networks are allowed to work on Planet Earth. Down here, you're restricted to much lower power outputs and much smaller antenna gain.

So, they used a much more powerful amplifier, through much less polluted air (I assume), and do not mention data speeds achieved (i.e. were they at all useful)?

Still cool, but let's not burst the polish baloon just yet :)

If we continue to see developments such as this...

[SwansonMarpalum]

It will only mean that last mile solutions will become more plausible for those who don't live within a couple miles of their CO. This is a Good Thing, as having Dial-Up and Satellite as your only options is pretty unbearable.

Any ideas

[Cpt Kirk]

So anyway what I want is wifi signal to get to my local pub :-) and to a mates house which is in the same direction. The pub is about 300m away (absolute maximum its probably around 150m really) and the mates house is about 1.5miles away. The equipment at present is a linksys wap54g and my laptop with a linksys 54g card.. I cant really get line of sight to either building but I might at some point in the future be able to put a repeated on the roof of the pub (which I can probably see from my roof). I want to do this using offshelf components. Any ideas anyone ? Cheers Cpt Kirk

Re:Any ideas

[really?]

Errr ... get Scotty to do it? (Use some thin sheet of that transparent aluminum you guys used to house the whales, and nobody will even know you have antennae up there.)

Re:Any ideas

[ZackSchil]

The more communication devices in a pub, the greater likelyhood for social disaster. Every single guy who drunkenly IMs his girlfriend to tell her about the hottie he's been mackin' in the bar will be out for your head.

Re:Any ideas

[mustangsal66]

If you have a big fat wallet. Looking either Breezenet gear ($1000 US per radio) which freq hops for security but at 3MB transfer.

For only around $10K, you can get Tsunami gear 100Mb PTP. It runs 5.4Ghz, just don't stand infront of it.

Wirless side note. I work with last mile wireless gear. It's cool, but also on our tower is XMRadio. These fookers run at 2.478 (Yeah they don't bother to tune their antenas much). Do the math here... 200Watt radio, 12-14DB gain antenea. Licensed at 200Watts at the antenea. Our spectrum analyzer pulled them in as the stongest signal WITHOUT and antenea. Our RF tech figured out they were running at about 1800Watts at the antenea.

The good news is there are no birds nests on the tower at all.

So come on down and have a cookout.

bad polish-english translation

[xxdinkxx]

when I went to http://www.poltran.com/ and inserted the article this is what came out. good luck making sense of it.

Firm appoint INTERLINE, as producer of microwave antenna will will settle leading polish , it has put verification of capability of juxtaposition of cordless link for purpose in (to) with sequence scattering of spectrum on distance in sphere of theoretical consideration standard 2.4 ( ) so far remaining paoemie GHz DSSS 802.11b. Purpose of venture, practical researching of capability was and on such link phenomena taking a stand. It belongs to underline, that ground was realized link in distinguishing from link realized (accomplished) from stratospheric balloon in sweden by firms 2002 year typically ( near the end Alvarion and important ) that plane Swedish Space Corporation, they are used all elements in experiment of firm on market unmodified available ( parabola 1.1 meter (subway) INTERLINE urzdzeniami/osprzetem and consolidator 500 ) mW - but it use parabolic antenna in sweden about 2.4 meter (subway) oerednicy and consolidator 6000mW. Two ultra localizations appoint on requirements of experiments wroclaw and room (shop) under snow white - highest up above Karkonoszy on midday (southern) east from yelenya gora -. Distance in simple line people (people) in effective experiment near 110 .km participation (quota) wzieli peter Kroplewski - owner firm wieslaw INTERLINE Karpowicz - chief production maciej Kaminski - department head technical krzysztof Mularczyk for affairs network cordless krzysztof - specialist Juszczyszyn point of -point was planned connection one of key period of experiment for station creating - technologist production localization choice (election) localization. First of they, it will will settle storeyed high-rise building on one of wroclaw 10. Second (other) localization, it for whole experiment under snow white key room (shop), silesian house beside resort on height 1400 m.n.p.m. We have chosen equipment for conducting of experiment following (step) equipment antennas - PARABOLIC maxi, 27 dBi - production point access INTERLINE - INTEL 2011 access culminating point Pro/Wireless - production firm cable SYBMOL and konektory - cable h 1000 BELDEN, h 155, chief council 316, card (kart) broadcasting wtyki VITELEC - PC Lucent ORiNOCO Card Silver/chipset Agere, consolidator ZCom XI-300/chipset Intersil certainly it has not run out laptops as additional endowments (outfits) about force 500 2 - 2.4 GHz mW. UPS, Kit of instrument, spare cables, zczki, konektory, even gas lutownica - just in case.
Installation - wroclaw as we have appointed deadline of (date of) realization of experiment among 12 time (sometimes) but 14 september 2003 year. Installing was first period and directing of antenna in wroclaw to part of massif OEniezki. Due to good visibility in day of installation in wroclaw ( 12/09/2003 ), this mountain (top) about height 1602 m.n.p.m. It was visible as on palm " ". It belonged to call attention (to pay attention) at visaing antenna on corner of tilting (pitching) antenna in vertical, as target (incoming) localization was placed on height 1400 m.n.p.m. But weight of experiment did not allow neglect this parameter. Elements of installations 1. Point of access INTEL 2011 access culminating point + consolidator Pro/Wireless 2.4GHz/500mW Channel 5 ( 2432 ) net _ MHz ID hardware wisznia Revision but AP Firmware Ver. 02.52-13 RF Firmware Ver. Radio V2.51-08 Type T2 Antenna Selection 10 10 ( ) 32 8000 ( ) 5 ( ) ( ) 20 100 100 5 60 min. (face) Primary Only wroclaw RF Configuration .DTIM Interval WLAP Mode Enabled .BC/MC Q Max .Max Retries d WLAP Priority hex .Max Retries v WLAP Manual BSS ID 00:02:B3:15:2F:55 .Multicast Mask d 09000E00 hex .Multicast Mask v 01005E00 hex WLAP Hello Time .Beacon Interval K-us WLAP Max Age .Accept Broadcast ESSID Enabled WLAP Forward Delay .MU Inactivity Timeout. IT (HI

Partial translation..

[Anonymous Coward]

Not a full translation.. just some of the more pertinent bits..

"Nalez.y podkres'lic', z.e realizowane ?a;cze by?o typowo naziemne (w odroz.nieniu od ?a;cza zrealizowanego pod koniec 2002 roku z balonu stratosferycznego w Szwecji przez firmy Alvarion i Swedish Space Corporation)
Co rownie waz.ne, wszystkie elementy uz.yte w eksperymencie firmy INTERLINE sa; niemodyfikowanymi urza;dzeniami/osprze;tem doste;pnymi na rynku(parabola 1.1 metra i wzmacniacz 500 mW) - a w Szwecji uz.yto anteny parabolicznej o s'rednicy 2.4 metra i wzmacniacza 6000mW.
Na potrzeby eksperymentu wyznaczono dwie skrajne lokalizacje: Wroc?aw i Hala pod S'niez.ka; - najwyz.sza; gora; Karkonoszy - na po?udniowy wschod od Jeleniej Gory.
Odleg?os'c' w linii prostej: oko?o 110 km."
==>
"It should be noted that this connection was ground based (in comparison to the record achieved at the end of 2002 by a Swedish company which used a hot air balloon)
What's also important is the fact that all the equipment used here is unmodified and readily available off the shelf (a 1.1m parabolic dish and a 500mW amp), unlike the Swedes who used a 2.4m parabolic dish and a 6000mW amplified.
For the pruposes of this experiment we used two locations, Wrcolaw and Hala pod Sniezka - the highest mountain in the Karkonoszy - south-east of Jelieni Gora.
Distance in a straight line - about 110km"

"Lokalizacje
Jednym z kluczowych etapow eksperymentu by? wybor lokalizacji dla stacji tworza;cych planowane po?a;czenie punkt-punkt. Pierwsza z nich, to 10 pie;trowy wiez.owiec na jednym z wroc?awskich osiedli. Druga lokalizacja, kluczowa dla ca?ego eksperymentu to hala pod S'niez.ka;, obok schroniska Dom S'la;ski na wysokos'ci 1400 m.n.p.m."
==>
"Location
One of the key decisions to be made was the location of the end stations in this point-to-point link. One station was the tenth floor of a Wroclaw block of flats. The second station was the hall under the Sniezka.. near the Dom Slaski shelter, about 1400 meters above sea level"

"Sprze;t
Do przeprowadzenia eksperymentu wybralis'my naste;puja;cy sprze;t:
* Anteny - PARABOLIC maxi, 27 dBi - produkcji INTERLINE
* Punkty doste;powe - INTEL Pro/Wireless 2011 Access Point - produkcji firmy SYBMOL
* Kable i konektory - kable BELDEN H-1000, H-155, RG-316, wtyki VITELEC
* Karty radiowe - Lucent ORiNOCO PC Card Silver/chipset Agere, ZCom XI-300/chipset Intersil
* Wzmacniacz - 2.4 GHz o mocy 500 mW"
==>
"Equipment
For this experiment we chose:
Antenna - a 'PARABOLIC Maxi 27dBi' by INTERLINE
Access points - INTEL Pro/Wireless 2011 Access Point - manufactured by SYBMOL
Cables and Connectors - BELDEN H-1000, H-155, RG-316 cable and connectors by VITELEC
Radio cards - Lucent ORiNOCO PC Card Silver/chipset Agere, ZCom XI-300/chipset Intersil
Amplifier - 2.4GHz at 500mW"

Damn.. I'm bored.. anyone else wanna finish this?

DonP.

Units

[easeofuse]

Time to get you Americans onto to the international system of units (SI-system)?
Stop arguing about kilometres all the time and get rid of "feet", "inches", "miles" and "pounds", "fahrenheit" etc. Or learn the transformation calculations. The US always has to be non-standard about everything (Haven't forgot Great Britain).
Don't you use SI-units when dealing with physics? Then it shouldn't be to difficult.

Oops

[Trak]

You also meant "Oops"

It's going to be one of those days, eh?

Re:Oops

[Cocoronixx]

lol. stupid acehole.

17... 18... 19... 20... *click*

my personal best: 21.7 miles with 802.11b

[puzzled]

I did a 21.7 mile shot using Cisco Aironet BR342, Andrew 19dB solid dishes, and YDI
500 mw amps.

I'm a bit embarrased to admit using a wireless LAN product for backhaul work, but some morons overtightened
the patch cable on an Andrew P2F 5.2-5.8 GHz 2' dish hooked to a WiLan AWE-120 5.8 GHz radio and put their link out
of service.

Despite extensive tweaking the link never managed more than analog modem speeds. It helped in recomissioning the UNI band stuff, but was otherwise
useless for hauling traffic.

802.11[bag] is NOT an access product. Take a look at Alvarion's Breeze Access II, or better yet just wait for an
802.16 product meant to do access work.

802.11[bag] is NOT a mobile access product. That market belongs to licensed band products with ISDN like performance offered by cellular companies.
Anecdotal evidence of mobile access to one police department in a town of 12,000 does not equal proof of concept for operation in urban areas; its plain
dumb luck coupled with no competing ISM band ISP(yet).

802.11[bag] is NOT a backhaul product. Backhaul radios are made by WiLan, Redline, Aperto, Proxim, and others. The minimum cost is $2,500 an end just for
the radio, most of them are in the UNI band, the full duplex products are generally split band 5.2/5.7 GHz, and they provide typically eight to ten
mbits for entry level products, unlike 802.11b which NEVER, EVER gets 11 mbits in long shots, with 1 or 2 mbits being the typical rate.

802.11[bag] SHOULD NOT BE DEPLOYED BY MONKEYS. Are you a MoNkEy? If you haven't read Matthew S. Gast's 802.11 book published by OReilly and you
don't fully grok the implications of the shared MAC layer, you are just throwing nuts and filth from the treetops into the already busy ISM band.

Slashdot's coverage of other topics is relatively even. The coverage of radio is focused on 802.11[bag] and this is quite laughable most of the time
to those of us who have actually owned and operated a wireless ISP. Personally I think the editors ought to be giving us a whole lot more information
on ICOM's D-STAR, a 23cm (1.2 GHz) amateur band voice/data system.

Yes, but ...

[SengirV]

Then they tried using a Ti powerbook and the range dropped to 20 feet. Grrrrrrrrr!!!!!!

nah

[waspleg]

you don't need tobe charged with anything to be detained indefinitely for being a terrorist

you just have to be suspected... better not try adding wifi to your donkey

Translation

[Anonymous Coward]

Below is my rough, quick and dirty translation of the article. You will have to mach the text to the pictures yourselves. AND it's Polish, not polish. For the difference of meaning see your favourite dictionary.

----

Wi-Fi - World Record - 110 km @ 2.4 GHz

Two-way DSSS communication in 2.4 GHz band at a distance of 110 km

INTERLINE company, leading Polish microwave antenna producer, set itself a goal to check possibility of establishing a wireless link in 2.4 GHz band with sequential spectrum spread DSSS (802.11 b standard) at a range currently being only a subject theoretical dispute. The aim of the enterprise was a practical assessment of possibilities and study of phenomenas concerning such a link.

It should be stressed that the link built is typical ground link and that diversivies it from the one built at the end of 2002 by Swedish company Alvarion and Swedish Space Corporation, which used a stratospheric baloon.

What is equally important, all elements used in the INTERLINE experiment are off-the-shelf, unmodified equipment available comercially (1.1 meter parabolic antenna and a 500 mW amplifier). Swedish experimentators used 2.4 m parabolic antenna and a 6000 mW amplifier.

Two localisations were chosen for the link: Wrocaw (a city) and a Hala pod Sniezka (Sniezka is a highiest mountain of Karkonosze), S-W from Jelenia Gora. The distance is around 110 km.

People
In the experiment actively participated:
Piotr Kroplewski - owner of the INTERLINE
Wiesaw Karpowicz - Manufacturing Manager
Maciej Kaminski - Technical Division Manager
Krzysztof Mularczyk - Wireless Network Specialist
Krzysztof Juszczyszyn - Manufacturing Technologist

Localisations
One of a key stages of the experiment was a choice of localisations for stations which were to create a point-to-point link. First of them is a 11 stage house on a one of Wroclaw's districts.
Second one, key to the experiment, is a glade by the summit of nieka, nerby Dom lski shelter (1400 meters above sea level)

Equipment
For the experiment following equipment was chosen:
Antenas: PARABOLIC maxi, 27 dBi - product of INTERLINE
Access points: INTEL Pro/wireless 2011 Access Point - made by SYMBOL
Cables and connectors: cables BELDEN H-1000, H-155, RG-316, connectors VITELEC
Wireless cards - Lucent ORiNOCO PC Card Silver/chipset Agere, ZCom XI-300/chipset Intersil
aMPLIFIER - 2.4 GHz, 500 mW

Of course there were also 2 laptops. Additionally we had: UPS, a set of tools, spare cables, connectors and a gas solder (just in case).

End-point Wroclaw
As the date of the experiment was set a time between 12th and 14th of September 2003.

First stage was mounting and directing an antena in Wroclaw to point towards nieka mountain. Due to good visibility in Wroclaw in the day of installation (2003.09.12), this mountain, which is 1602 meters above sea level, was clearly ivsible. During the directioning vertical angle was important, due to the fact, that the other end of the link was 1400 meters above sea level.

Installation components
1. Access Point
INTEL Pro/Wireless 2011 Access Point + Amplifier 2.4GHz/500 mW
(here you can read yourself)

2 Antena cable
Belden H-1000
Length: 5 meters
plugs: type N

3 Connector
INTERLINE N/RP-BNC
Length 30 cm (0.3 m)
plugs: type N and RP-BNC

4 ANTENA
INTERLINE PARABOLIC maxi
type: directional parabolic antena
gain: 27 dBi
radiation angle: 4degrees/6degrees

Installation - Karkonosze mountains, Kopa-nieka
On 14th September 2003 all the equipment has been transported with OPEL Frontiera (we had obtained permission of the Karkonosze National Park authorities) to the meadow near the nieka's summit.

On the installation place weather was as usually in the mountains. Almost all the time the place was covered by clouds. Only from time to time for a dozen seconds wind split the clouds and we were offered splendid views of surrounding mou

world record == beer

[hajejan]

Actually Guinness world record == Guinness beer but that is beside the point

They lie!

[yotto]

It is NOT 112640 meters! It's only 110,000 meters!

Dont tell me getting the angle was hard.

[Bruha]

During the directioning vertical angle was important, due to the fact, that the other end of the link was 1400 meters above sea level.

I have routinely setup shots to a satellite that's the size of a volkswagon at 230,000 Miles using a 20M dish. It takes some time!

Re:burritos

[sacrilicious]

Who needs a microwave when you can just stick the burrito in the access point's line-of-sight? I suppose that could possibly affect throughput as well...

Burritos always increase throughput in OUR house...

Re:WOW! THE DISTANCE!

[nocomment]

"stretching the range of a Wi-Fi network for an amazing 110 Kms "

That's gotta be what 8 miles??? Someone help me with the math here. ;-)

i forgot

[_avs_007]

to mention that while the Netgear G I measured 21mb/sec, I was never able to get more than 17mb/sec with the Linksys G.

When doing tests at the office, I found the range of Linksys G to be similar to first generation A. I actually saw about a 1-2mb/sec drop in throughput with every couple steps I walked from the AP. Even with the Linksys signal boost attached, I still saw this behavior. I'm guessing that the Linksys Signal booster amplifies noise along with the signal, and a good "cleanup" algorithm was not provided, such that the boosting was worthless.

Nice mountains

[butane_bob2003]

Hope they dont plan to leave that crap up there. Those mountains are pretty. Dont need a bunch of funny looking geeks and equipment fouling it up. Don't they have any buildings in poland tall enough to install that thing on?

Re:Nice mountains

[JarekC]

Of course they haven't left anything there. Mount Sniezka is in the Karkonoski National Park and in Poland they treat their nationat parks quite seriously. The guys from Interline even had to obtain the special, one-time permit to enter the Park in a car - the scanned permit is attached to the article. BTW, as you can seen on the scan, the permit costed them 100zl which is about 25 USD. I'm surprised it was so cheap.

Impressive, but anyone could do the same for cheap

[anethema]

From looking at the pictures, they just used a parabolic dish antenna. You will get about 20-24db gain on one of those and it narrows the beam a LOT for that gain. So dont think anyone within 110km can log onto the network and lan away. This is a strictly point to point thing.

Ive got two c-band dishes right now with a point to point network around town. The longest link is around 30km. if i dindt live in the mountains(of if i wanted to hike to the top of said mountains) i could get a link as far as the curvature of the earth allowed me. Two ten foot dishes with 30-35 dB of gain is capable of amazing things at 2.4ghz.

OH, and about legality. 500mW will be legal anywhere. But with a dish gain of 24dB, they will have a equivelent power of around 128 watts. DEFINATLY illegal, at least here in canada.

If anyone is interested in playing wiht this and they dont have a lot of cash, there are lower cost ways to do it.

You can take any parabolic dish, which can be had for about 50 dollars, and use a cantenna as a feedhorn. Or if you wanna spend 20bux more, just go to Pacific Wireless and they sell a 2.4ghz dish and feedhorn, with 24dB of gain, for 70bux. even comes with the pigtail.

For a cheap amp, you can buy 1 watt 2.4ghz amp IC's for very cheap. Here is a site that has a schematic and board layout for it.

With a watt and a 24dB gain antenna, you have an ERP of about 256 watts.

Have fun!

Re:Impressive, but anyone could do the same for ch

[bovinewasteproduct]

For a cheap amp, you can buy 1 watt 2.4ghz amp IC's for very cheap. Here is a site that has a schematic and board layout for it.

And very illegal in the US. Your not allowed to build your own gear unless your a Amateur radio operator operating in the Amateur bands. I'm willing to bet that Canada has the same kind of regs...

BWP

No world record -- It's been done before

[Dan Ferguson]

It's not new.. There was a 72 Mile link setup in Alaska several years ago. 2.4Ghz unlicensed.

I agree, it is neat but not a world record.

Re:No world record -- It's been done before

[DHR]

Haven't heard about any in Alaska, but there was a 72 mile link in San Diego, which, by the way, is 115 Kilometers.

http://www.computerworld.com/mobiletopics/mobile/s tory/0,10801,75830,00.html

Re:Impressive, but anyone could do the same for ch

[thebigmacd]

If you are an EE student in university or college here in Canada chances are you will end up building transceivers that operate on licenced FM bands, and they may or may not be legal, depending on the adherence to law by the prof, and his or her mood that day

In other words, go to college and do tons of illegal stuff in the name of education :D

Re:WOW! THE DISTANCE!

[typobox43]

It's about 68.35 miles.

Uh World Record?

[1Oman]

I think These guys have them beat.

A fools tongue runs wild again.

[skogs]

Sorry man. This is redundant, but I still can't get over how dumb the FCC comment was.

Even if you DO go over that FCC limit...whos checking? Do you think the FCC is going to wander by my house, directly in line of sight of my dish and measure me?

It is directional...they can't monitor it from their spaceship parked over washington.

MOD Parent Up Please

[Krashed]

This guy has the right idea. Yeah you could set up a WiFi network across great distances but why? That was probably done under ideal conditions and won't work when raining. If you really need to pass data that far, just stick with the internet. Set up a VPN for security and you will be much more secure and will go greater distances that WiFi could ever be.

overlap?

[StateOfTheUnion]

Are 1,6, and 11 the only channels that don't overlap?

Re:overlap?

[LostCluster]

All of the channels basically overlap with the other channels. However, if you're on 1, 6, and 11, you manage to cover the entire chart without duplicating yourself.

Translation: They're covering the entire 2.4 GHz band, and making no appoligies to anybody else who hoped to use it near their systems. Any 2.4 GHz phones will have nowhere to hide.

Re:overlap?

[pe1rxq]

You could also use 2, 7 and 12 or 3, 8 and 13 as the spacing would be the same....
If you really push it you can use smaller spacings such as three or four channels instead of six.

Jeroen

Re:overlap?

[misleb]

There is only 1-11 in the US.

-matthew

Re:overlap?

[pe1rxq]

Hadn't thought about that...
We have 1 to 13 here in the Netherlands.
(Besides its not that hard to use all fourteen)

Jeroen

Re:overlap?

[jerde]

Are 1,6, and 11 the only channels that don't overlap?

You can get away with using four without much problem. I use 1, 4, 8, 11 for my wide-area 802.11b network.

You have to plan out in 3 dimensions when you have multiple access points like that. Often the strongest signal available to a roaming user is above or below them, rather than on their floor.

With only 3 channels available, it's too hard to map them out. With 4 you can at least guarantee that no two adjacent access points are on the same channel.

- Peter

Re:overlap?

[StateOfTheUnion]

Speaking of overlapping channels and consuming large sections of the 2.4 Ghz bandwidth, is there any Ez way to identify what other things may interfere with WiFi on a ceratain channel or channels (e.g. 2.4 Ghz cordless phone, wireless headphones, etc) or is it really just a crapshoot and one has to search for open bandwidth through trial and error?

Re:overlap?

[pe1rxq]

Thats what you get with unregulated pieces of spectrum, everyone can put its crap on it....
You could use a spectrum analyzer to monitor 2.4GHz band to see if anyone in your neighbourhood is using it.

Jeroen

Re:overlap?

[LostCluster]

Not really. The 802.11 definiton for the channels are not used by anything else. So, if your 2.4GHz's interface claims there's 20 channels, you just have to guess if those channels are just 1/20th slices of the same pie, or if they've jumped around in their numbering scheme so that one click can get out of the footprint of most problems. You really don't know what your own devices are doing, so how can you predict what the neighbor's are throwing in?

Trial and error it is...

Re:overlap?

[PetWolverine]

With 4 you can at least guarantee that no two adjacent access points are on the same channel.

Is this a consequence of the four-color theorem? It sounds distantly related.

Re:overlap?

[Anonymous Coward]

Get the wifi detector from thinkgeek.com. It's just a 2.4GHz radio signal strength meter, and will tell you if anything is using that frequency. It's fun to use it in the kitchen while microwaving.

Re:overlap?

[Grant29]

If you have the Linksys WRT54G, you can use a hacked firmware to get all 14 channels. Check out http://www.sveasoft.com/modules/phpBB2/viewforum.p hp?f=6 for the forums on how people are doing it. I'm not sure if you can hack the wireless lan card do access the same channels or not. They sell the WRT54G domestically and internationally. The chipsets can handle all the channels, but the firmware limits the US version to 1 - 11.

--
Retail Retreat

Re:overlap?

[wankledot]

Yes, except with wireless there are no solid boundries, so it's not completely the same. You could have 6 non-overlapping channels are still have interfearance problems if they are stepping over each other. . It's very possible to have overlapping pieces, but as long as you manage your power levels and design it well, you should be OK.

Re:overlap?

[cyberformer]

True, and the 2.4 GHz. phones will also stop this chipset from getting a lot more than standard Wi-Fi. Basically, it's only useful if you have a single Wi-Fi AP and no other cordless phones, APs, Bluetooth gadgets or microwave ovens within a few hundred meters.

The best solution is to move to 5 Ghz. (802.11a), which has 13 non-overlapping channels. But this has a slightly shorter range, and chips are still slightly more expensive.

Re:overlap?

[tcgroat]

This channel-hogging system is just as bad as using high-power amplifiers to blow other users off the channel. "My system is the only one that counts. I won't share with anybody else." It takes many times its fair share of a limited resource, ignoring a deliberate design strategy to use limited power (range) and reduced bandwidth. That design strategy exists to enable cooperative sharing of the available spectrum. The parallels to the me-first hooliganism on 27MHz Citizen's Band are frightening. Without cooperation and compliance to established standards and regulations, the range and through-put arms race will make wireless LANs useless to everyone.

Re:overlap?

[pimpin apollo]

Maybe I'm missing what you're getting at, but the 802.11b definitions for channels aren't used by anything else, but the spectrums that they cover are still unregulated... which means that anything can use it.

Now if you're saying that you can't see those with a 802.11 aware device then yeah, but if I made some device that just broadcast randomness on the 2.4-2.5ghz range then that would interfere with all of those channels. It's also interesting to note that these ranges differ depending on the country. Japan's different than US/Canada.

The full ranges are in the kismet documentation if I remember correctly.
But the overlap is because the upper freqency for channel 1 is 2.423 while the lowest end for channel 6 is 2.426. 5 ranges from 2.421 to 2.443.

Still, the FCC doesn't have any say over what those channel mappings are; meaning that a cordless phone could easily interfere with those channels (and does).

Re:overlap?

[LostCluster]

That's my point... that if your 2.4 GHz phone allows you to pick a channel, those channel numbers alone tell you nothing about which one to pick to get out of the way of your own WiFi, they're meaningless.

More throughput... but...

[kneecarrot]

More throughput but more pesky interference with phones and whatnot.

Re:More throughput... but...

[Anonymous Coward]

More channels=less interference, not more. If a cordless phone interferes with (say) channel 6, the other 2 channels remain undisturbed. This may be more microwave resistant, but microwaves may spread noise around too wide a frequency block to totally ignore.

To summarize, using more channels will allow the network to route around interference, reducing its effect.

What about 802.11G?

[Ckwop Johnson]

If it works for that it'd be well cool and would give speeds close to a wired network...

Simon.

Re:What about 802.11G?

[jabbadabbadoo]

Well, 802.11G beats most wired networks already. Believe it or not, tons of LAN's are still at 10Mbps and many 100Mpbs networks have effective throughput much lower than 802.11G due to hopeless hardware configurations.

Re:What about 802.11G?

[fidget42]

If it works for that it'd be well cool and would give speeds close to a wired network...

Actually, no. A wired network provides a dedicated connection, while a wireless provides a shared one. This is basically the difference between 10baseT and 10base2. The shared connection (wireless and base2) will have to deal with collissions and will yield about 20-30% max load (depending on the kind of traffic). This is why your G network will only yield 11Mbps and not the full 54Mbps. Your 100baseT network will blow away anything wireless, unless you want to go with a dedicated wireless link (and then, um, why is it wireless?).

Re:What about 802.11G?

[pe1rxq]

If by dedicated you mean only the systems connected to it and not your neighbour than yes...
However all ethernet standards 10baseT, 10base2, and also 100baseT are shared.... thats why they have things like collisions.
You can give it the appearance of a dedicated network by using routers instead of dumb hubs.

Jeroen

Re:What about 802.11G?

[fidget42]

By dedicated, I mean that there is only one NIC talking and one NIC receiving. As long as you have two NICs talking over the same channel you will have collissions and a degraded network. The RF channel is basically a "dumb hub."

Re:What about 802.11G?

[TheCrazyFinn]

Incorrect. This is only true for Switched Networks, you have bandwidth sharing on a 10baseT/100baseTX network if hubs are used network or a 10base2 network.

However you are correct that 100baseTX will blow away 802.11g anyday even in a hub-based topology(In fact, with a properly designed network, switched full-duplex 10baseT will outperform 802.11g)

Re:What about 802.11G?

[TheCrazyFinn]

Incorrect. 802.11g's practical max throughput is around 25Mbps (Half of theoretical max) and even if all of your clients are running .11g cards, you have a shared bandwidth topology. Given the same restraints, the almost 100% bandwidth advantage of 100baseTX will show.

In fact a switched 10baseT network will perform about as well as an 802.11g network, and possibly better if you can run all of your systems in Full-Duplex mode (Not a given for 10baseT hardware)

Re:What about 802.11G?

[TheCrazyFinn]

That's a switched network, not a 'dedicated' one. Yes, the RF channel is a 'dumb hub' but many 100baseTX implementations are also 'dumb hubs'. 100baseTX Switches are ubitquous now, but that's only happened in the last couple of years, and many large networks are still hub based due to cost reasons.

Re:What about 802.11G?

[TheCrazyFinn]

I think you mean a switch, not a router. A router can do this, but at a major performance cost. A switch does this by design.

Oh, and 1000baseTX is a switched-only Ethernet(Of course, it's only really ethernet due to marketing decisions).

Re:What about 802.11G?

[timeOday]

If I understand correctly, you're saying 10base2 is shared while 10baseT is not? That's not true. Both wire types are used for ethernet, and both are shared. Ether way, collisions aren't that big a deal after all, see the classic reference:

Ethernet works in practice, but allegedly not in theory: some people have sufficiently misunderstood the existing studies of Ethernet performance so as to create a surprisingly resilient mythology. One myth is that an Ethernet is saturated at an offered load of 37%; this is an incorrect reading of the theoretical studies, and is easily disproved in practice. This paper is an attempt to dispel such myths.

...

Figure 10 shows excess delay , a direct measure of inefficiency. It is derived from the delays plotted in figure 8. The ideal time to send one packet and wait for each other host to send one packet is subtracted from the measured time. The time that remains was lost participating in collisions. Notice that it increases linearly with increasing number of hosts (offered load). When 24 hosts each send 1536-byte packets, it takes about 31 milliseconds for each host to send one packet. Theoretically it should take about 30 mSec; the other 1 mSec (about 3%) is collision overhead. Figure 4 agrees, showing a measured efficiency of about 97% for 1536-byte packets and 24 hosts.

The upshot is that ethernet can carry very close to its rated capacity even if there are a lot of hosts and a lot of collisions. (Of course nowadays we tend to use switches instead of hubs anyhow, but that's not a at all inherent in 10baseT wiring).

Whether wireless will work quite this well, I don't know.

Re:What about 802.11G?

[42forty-two42]

Oh, and 1000baseTX is a switched-only Ethernet(Of course, it's only really ethernet due to marketing decisions).

Actually, it's called "ethernet" because its frame format is identical to that of the slower variants, and it supports autonegotiation to be backwards-compatible with 10Base-T and 100Base-TX.

Re:What about 802.11G?

[pacman on prozac]

Hrm something I read recently, possibly the O'Reilly Ethernet book said that 30% limit was for the standard before the full CSMA/CD functionality was added ,i.e. the old experimental slotted aloha nets.

With the CSMA/CD the rates went up to the 90s

Re:What about 802.11G?

[jabbadabbadoo]

"802.11g's practical max throughput is around 25Mbps "

Well, that's certainly not my experience. At our shop, we utilize at least 80% of the theoretical 11g throughput.

Where on earth do you have this information from?

Re:What about 802.11G?

[TheCrazyFinn]

A combination of the inherent issues with a shared bandwidth topology (Collisions, intereference between nodes) and the excessive overhead inherent to 802.11b and 802.11g packets.

So, you actually are getting 5+ Megabytes per second transfer rates out of 802.11g? Unless you have only one AP and one client, I call Bullshit.

Re:What about 802.11G?

[engimeer]

27 MBPS is the maximu data thruput you will get from 802.11g @ 54 MBPS. bulls--t someone says well consider that the 54 MBPS is the absolute maximum data rate that infomation can be sent over the 802.11g channel. So in one second 54 million bits can be transfered from one user to another. But not all of those bits are actually data being transfered. Some of the bits are used to tell all the airwave users how the AP (if there is one) is setup. Remember to communicate over a link all the users (at least the sucessfull ones) must speak the same language. so some of the bits are used to tell all of the users waht language to use (beacons). In 802.11 all communication between users are are done in packets of data, all packets are acknowledged (ack packets) by the receiver on proper receiption. The time it take to send the acknowlement packets uses up some more of the bits. There is also short gaps between the packet and the ACK packet where no data is sent, more bits lost from the actual thruput. All packets are preceeded by a header that contains information to allow the receiver to synchronize with the incoming packet and properly decode the packet bitstream. the header also contains a bunch of bits that describe the packet's properties ie. length, modulation, source address , destination address... this header also take time and uses up even more of the bits. for fair use of the airwaved channel each transmiter is required to wait a random time interval after the reception of an ACK packet before transmiiting. this results in quiet times when no one is transmitting. thus more lost bits that don't count towards thruput. when one looks at all these lost bits over the full second time interval one finds that they total at least 27 million bits. thus the maximum theoretical thruput is 54 - 27 = 27 million bits ie 27 MBPS. thus if you are getting 25 MBPS thruput on your 802.11g network congrats you are getting just over 92% of the rated capacity!!!! BTW 80% would be 21.6 MBPS not too shabby engimeer

Tragedy of the commons forming!

[LostCluster]

Of course, if you use the entire 2.4 GHz band, your neighbor can't. That's part of the reason why we have multiple channels to keep everybody from running into each other time. I highly doubt this group has bothered to test what kind of downside there is for a standard-issue WiFi setup operating 100 yards away.

Re:Tragedy of the commons forming!

[MrBlue VT]

I live right next to a university and I can see at least 15 different access points on any given day from my wireless link. I use it for internet access to the university and I can definatly tell when my neighbors are using their own LAN cause it causes a lot of packet drop outs. Not to mention about half of those APs have "linksys" as their SSID with no WEP enabled.

It gets better during the summer when a lot of the students around me leave and shut off their APs.

Re:Tragedy of the commons forming!

[sploxx]

Yes, but consider that it should be already possible (never tried it) to put multiple WiFi cards into your router and bundle the bandwidth!
Probably, soon everyone needs such a card to shout loud enough between all the other people in your neighbourhood who have already such a thing.

If the cards are smart enough to not completely cease to work if there is a wifi traffic jam - if they scale back on the number of channels occupied, everything should be ok(?)

Re:Tragedy of the commons forming!

[bbdd]

mod up the parent. this is a big problem.

i live in a tightly populated suburban area and i can see 8 or 10 APs immeditately around my home using simple tools like netstumbler. this doesn't count APs that don't announce their SSID, as well as who-knows-how-many 2.4ghz cordless phones.

my 2.4ghz cordless phones get interference all the time from what i can only assume are everyone elses APs and phones around me.

simultaneous multiple channel use is a bad idea, unless you are out-of-range of others...

Re:Tragedy of the commons forming!

[Anonymous Coward]

Time to get a few cards and use a bonding driver.

(salivating)

Re:Tragedy of the commons forming!

[jaoswald]

Given that you seem to know that the 2.4GHz band is already too crowded, I can't understand why you got a 2.4 GHz cordless phone when there are already perfectly good bands at 900 MHz for cordless phone usage.

Sure, I can understand the average consumer might get dazzled by the prospect of having more gigahertz than his neighbor's wimpy phone, but an above average slashdotter?

Re:Tragedy of the commons forming!

[WolfWithoutAClause]

Of course, if you use the entire 2.4 GHz band, your neighbor can't.

Well, if you use it all the time (which is rare) then thats true with current APs.

However, that's not necessarily true of future APs though. There's no reason why an AP can't use a directional aerial (e.g. phased array) to ignore the other APs and users, and then everyone can use the same frequencies.

Re:Tragedy of the commons forming!

[MrBlue VT]

I have a 14 dbi parabolic antenna on my wireless device and I still pick up a ton of signals from other APs besides the one I'm aimed at.

The directional antenna definately helps, but it won't solve all the problems.

Re:Tragedy of the commons forming!

[WolfWithoutAClause]

14 dBi isn't very sensitive- it's only about a 10x gain. That means that approximately someone 3x closer to the AP will swamp you out.

For directionality to work, it requires widely spaced antennas (many meters), and this allows far more discrimination than your aerial.

Re:Tragedy of the commons forming!

[Anonymous Coward]

Just log in to their default-passworded APs and set them to use channel 1. Then set yours to use channel 6. Let them deal with packet loss.

Re:Tragedy of the commons forming!

[jandrese]

Last time I looked for a phone all of the 900Mhz phones were pure crap. It was obvious that 900Mhz is considered a "low end" feature these days and only the cheapest POS phones use it. The vast majority of the phones were 2.4Ghz, although there are more and more 5.8Ghz phones coming out (but they are very expensive). Also, even if you buy a fancy 5.8Ghz phone to avoid conflicting with your network, you need to read the manual carefully. Apparently many "5.8Ghz" phones are actually only 5.8Ghz in one direction (base station to phone), and 2.4Ghz on the phone->base station path.

I ended up buying a 5.8Ghz phone myself because I needed to be able to run multiple phones from a single jack, and none of the 900Mhz phones supported that.

Re:Tragedy of the commons forming!

[Anonymous Coward]

Spot on!

Re:Tragedy of the commons forming!

[t0ast3r_b0y]

Don't you mean 25x over isotropic? (=10^(14/10)) It's not an order of magnitude difference, but still. So the opponent would need to be 1/5 the distance from the AP to match your power.

I'm not really sure how equal power equates to being "swamped out" either, since the medium access control should divide the bandwidth perfectly in half when the AP can hear the two contending nodes equally well.

Maybe not, never had a class that mentioned wireless MAC, only wired.

Re:Tragedy of the commons forming!

[Lennie]

If I understand this right, what you then could do is use a full-duplex system, when using 2 channels, one for sending, one for sending from the otherside (receiving).

This could really speed it up when using directional equipment.

Re:Tragedy of the commons forming!

[bbdd]

you are assuming that i got my phone after they got their APs. :-)

Overlap explained

[phreak03]

Any connection uses actually, the three channels around it for the connection anyways,
if you've ever tried actually haveing 11 acess points on different channels you'll notice massive interfearence

Re:Overlap explained

[jdhutchins]

A connection, by default, only uses one channel. However, it spills into adjacent channels because of the quality of the transmitter and the fact that the channels are fairly close together and narrow.

Firmware

[ModernGeek]

It seems like a fairly good idea, but also vary expensive to upgrade everyone. It seems it might be able to work if it was able to be done via a firmware upgrade though. For all major routers (Airport/Linksys/Dlink) and their fellow cards. I think the best thing todo is to make an airport card that fits the normal slot, and pccard ones from linksys/etc that are able to be upgraded by firmware, with expandable hardware. 802.11b is almost set in stone because the costs of upgrading are just too high.

Re:Firmware

[The Clockwork Troll]

The immediate benefit to legacy clients is that they can be partitioned into 3 channel groups, each with its own full allotment of 802.11g bandwidth.

You would only need a hardware upgrade if you wanted each client to be able to make use of multiple channels simultaneously and reach that 50Mbps throughput figure quoted in the article.

Otherwise it's a solution for reducing bandwidth contention in heavily trafficked networks (and protecting 802.11g users from bandwidth degradation by 802.11b clients, as mentioned).

Frequency band to be reorganized?

[Anonymous Coward]

Won't these things running at 802.11 MHz be affected by the FCC Reorganization of the 800MHz Band?

Re:Frequency band to be reorganized?

[Devil's BSD]

802.11 is the IEEE standard, and the 'b' section of that pertains to a wireless network capable of 11 MBps (the 11 in 802.11b has nothing to do with the 11Mbps theoretical throughput, just a coincidence.) In reality, 802.11a, b, and g operate in the 2.4 GHz range, like the 2.4GHz cordless phones.

Re:Frequency band to be reorganized?

[Anonymous Coward]

No, 802.11a is in the 5ghz spectrum.

Re:Frequency band to be reorganized?

[Anonymous Coward]

Incorrect - in order of approval (IEEE)
b was first - 11 Mbps at 2.4 GHz

a - approx 54 Mbps at 5.8 Ghz

g - they were able to use OFDM on the 2.4 GHz channel, to obtain the same speeds as A, while not losing range due to higher bandwidth, and keeping costs down (by not having to make transmitters for the higher 5.8 GHz chuck of spectrum)

As if Wi-Fi space wasn't crowded enough already...

[misleb]

I've been in places where you can't find a free channel because there are too many other people using Wi-Fi in the area. Now we're going to have individuals using ALL of the non-overlapping frequencies? That really sucks. As far as I am concerned, Wi-Fi as we know it will not go very far. There is just no way people are going to be able to share such a limited frequency spectrum... not in densly populated areas, anyway. I'll take good ol' reliable wires any day. Wireless is overrated.

-matthew

no trimode?

[MoFoQ]

no 'g'?

but it's a good idea.
Hopefully, other chipset makers (TI, etc.) follow suit, which in turn will reduce costs (thx to competition).

Of course, if it can do all three, 'b', 'a', 'g' separately, and each with the parallel-ness, that would kick ass.

Re:no trimode?

[LostCluster]

They're doing neither 802.11b nor 802.11g... they're violating the part of the specs that say they should only be on one channel. Therefore, their devices are compatible with both... but they're doing a flawed implementation on purpose to trade the performance gain for taking the entire 2.4GHz band as theirs.

Re:no trimode?

[MoFoQ]

if that's the case, then I guess others can have something similar by using several chips "in parallel"

Warning: Embrace and Extend logic detected

[LostCluster]

They're basically getting all of their performance gains simply by violating the part of the WiFi standard that says you should only use one channel at a time, and leave 2/3 of the bandwidth space for other possible applications. Not to revolutionary a concept... just one that causes problems only for people other than the buyers of their systems.

It's known that mixing 802.11b and 802.11g on the same network causes slowdowns... their effective solution is to put the 802.11b devices on a different channel and therefore a different network than the 802.11g devices and join the two networks at their access point.

Might this introduce potential bugs?

[James A. M. Joyce]

I don't know a great deal about wireless networking, so maybe I'm totally off base, but is it possible in certain situations for this to cause interference between different RF channel users? Or if a new user came onto a channel being multiplexed?

Some comparrisons regarding G

[up up down down lrlr]

I work with a lot of wireless APs and client cards in our lab.

If you are talking about G type stuff, stay away from Linksys, they have the crappiest range. When I used it in my house, I would get 68db with an Intel 802.11b AP, but the Linksys G router/AP yielded 77db, and that was only going through 2 walls.

I replaced it with a Netgear WGR614, which uses the Intersil Prism GT chipset (as does the D-Link we tested), and got much better range. Similar to straight B. ~68 or 69 db in my master bedroom.

In our office environment, the Linsys G would drop signal after walking past the conference rooms. The Netgear G allowed us to almost walk around the entire floor. I connected a signal booster, and found it to be next to worthless, as it did not improve range. If it did, only by 5 ft or so. It still dropped signal as I walked past the conference rooms.

The measured actual throughput was 4.5mb/s with straight 802.11b, and 21mb/s with the Netgear G.

Quite suprisingly, I had the best results with the Netgear WAB102 Dualband A/B, which is the only A/B AP that uses Atheros second generation A. Tom's Hardware had a write-up on this. Atheros had a whitepaper. I bought 3 of these, and verified the claims.

With a Linksys A+G card, (which uses Atheros 5001X+, as does Netgear WAG511), I got slightly weaker signal strength in my master bedroom 70db), but throughput killed both B and G. I was measuring 24mb/sec throughput in non-turbo mode, and 45mb/sec in turbo mode. In the office, I was able to sustain 7-11mb/sec at the opposite end of the building. The Netgear G was only able to sustain 1-2mb/s. Inside the conf rooms, Linksys G had no signal, Netgear G sustained 7mb/sec, Netgear A in turbo mode sustained 24mb/sec.

In the office, the range of this second generation A actually exceeded that of B, which is something Atheros pointed out in their whitepaper. They said while true A can't go through walls as well as B, the 1st generation A was not performing up to its capabilities. Kind of like how Shannon's law states what is the maximum amount of data that can be carried across wireless, but current technology does not even begin to approach this limit.

I've tested various client cards from Orinoco, to Cisco Aeronet, Prism 2 and Prism 3 cards, and various Atheros based cards. I that the AP affected range more often than the client cards. Though I have found that anything based on the Atmel chipset to be crap. The USB 802.11 card from Linksys (V2.6) uses this chipset. Unfortunately, the Netgear WAB102, uses Atmel for its B, so its B is crap as well. I just use the A portion of it anyways. But the new Netgear triband router, I beleive uses Atheros for all three bands, it just costs an arm and a leg.

The Linksys Triband AP, only uses Atheros for the A, it uses Broadcom for B and G, so its G sucks just like the Linksys B/G stuff.

Somewhere I also read that Linksys will not support any turbo modes in their AP/Routers. (though their A+G client card still supports turbo). Both Atheros and Intersil have planned turbo features. Atheros already had 108mb/s A support in turbo, allowing 45mb/sec throughput by using multiple channels. They already have support for hardware compression, so are promissing a future firmware update that will flip this on, that will allow a turbo mode to sustain 90mb/sec throughput. Its called SuperA. They just released SuperG, which uses multiple B/G channels and compression, to allow 108mb/sec, and I think 45-60mb/sec throughput.

Intersil's turbo technology is called Nitro. Similar (but incompatible) with Atheros's technology.

Re:Some comparrisons regarding G

[Anonymous Coward]

USR8054 is a pretty good 11g router, one of my neighbours has one and I get pretty good speed through it even when the signal is severly degraded (Not too sure where they live, so I can't comment on the range). It also has an excellent web configuration interface.

Re:Some comparrisons regarding G

[bru_master]

This is good info to have, Keep in mind if you are trying to impliment wireless in a corporate environment, crappy range is a good thing. I have common problems with Cisco and Symbol AP's having such good range that too many users will pick up the signal in the cube farms of todays corporate america.

I try to place my AP's so that 25 users will access them from there desks or conference room. Some conference rooms that are very large I will place 2 or 3 AP's on different channels with the power turned all of the way down so it will balance the user load between the them.

Since there are only 3 non overlaping channels it is often a chore to design wireless in a room where the same channels dont overlap with each other. Poor range solves this problem. Think of how to put 5 AP's in a room with 3 channels, it can be done, poor range is the key.

We urge our users to use their wired connection and use their wireless when in meetings or on the road at other corporate offices.

Re:Some comparrisons regarding G

[rfmobile]

I will place 2 or 3 AP's on different channels with the power turned all of the way down so it will balance the user load between the them.

This is a great example of an intelligent use of the 802.11X protocols. Use only as much power as you need, and only where needed. As opposed to the usual (and wrong) tactic of using full-power in an attempt to squash a neighboring access point's signal.

-rick

Re:Some comparrisons regarding G

[Garak]

Are you refering to the Linksys client cards or the linksys wireless routers like the wrt54g?

Are the output power the same on both of the cards/AP's you tested?

Re:Some comparrisons regarding G

[rsmith-mac]

There are some inaccuracies I'd like to point out, if you don't mind:

Somewhere I also read that Linksys will not support any turbo modes in their AP/Routers
Linksys is supporting a "turbo" mode, thanks to Broadcom's "Afterburner" technology, which is implemented as Linksys's "SpeedBooster" technology. Afterburner requires a new revision of Broadcom's 802.11g chipset, however, so previous G products can't be enhanced, only new products.

Atheros already had 108mb/s A support in turbo, allowing 45mb/sec throughput by using multiple channels
Atheros and Broadcom are taking 2 different approaches to "turbo" here; while SuperG uses multiple channels(and is proven to degrade other networks, albeit mostly Broadcom's, oddly enough) along with compression and other effeciency boosting technologies, Broadcom's Afterburner will not be using any sort of channel bonding, just effeciency boosting. This is an important distinction, since Atheros' implementation will be faster(more raw physical bandwidth), but Broadcom's implementation will be a "good neighbor" to other devices. Of course, if you even have to deal with other devices, you're screwed anyhow; just having a B device in the same sphere will require G devices to slow down to warn the B device, so all your fancy effeciency boosting tricks also get disabled.

Anyhow, check out Tom's Networking's review of Linksys's WRT54GS router; it is loaded with information on SuperG, Afterburner, incompatibilities, and performance.

Re:Some comparrisons regarding G

[Anonymous Coward]

Most valuable posting to me personally for months.
Thanks.

Re:Some comparrisons regarding G

[matty619]

Of course, it only takes 1 jackass with a 200 mW Senao long range card to associate with one of those low power AP's and you'll find that spectrum tightening up fast!

-M@

Re:Some comparrisons regarding G

[Geordie Korper]

In my real world experience this is not true. I just tend to see very bad performance from the movement of all the interfering water bags (human bodies). Even small movements of a classroom of students cause the clients to reacquire a different access point. Every time that happens there is a slowdown. It is worse in situations where there are access points at high enough density that a client in the back of a room can acquire a signal from the other side of a wall instead of the other side of a room. With low signal strength it was just harder for a client to lock on to any signal. Of course if you do really good placement, antenna tuning, etc. strength tuning can help. On the other hand if you do that, strength tuning is usually not necessary.

No way

[Wesley Felter]

It's pretty unlikely that a firmware upgrade could turn a single-channel radio into a multi-channel radio.

Re:No way

[Deliveranc3]

If you think about it the router can link to at least three cards.

Most cards can link to at least three cards

Use 3 connections between them and triple the throughput simple. Should work problems asociated with massive throughput aside should work well.

My friend's network goes out when he receives a phonecall course he has a linksys router :)

Interference

[Ctrl-Z]

This type of idea is not new, and I have seen it in wireless routers/nics for months. The primary drawback is that if you are using up all those channels, your neighbour's wireless network won't have anywhere to go. Conversely, if you are that neighbour, it wouldn't make you very happy.

I consciously decided against buying something like this for that very reason when I bought my wireless hardware, even though the cost difference was negligible.

Yeah! Screw the neighbors!

[Anonymous Coward]

Take up all the channels, get a stronger transmitter, and knock their wireless out!

Re:Yeah! Screw the neighbors!

[LostCluster]

Exactly. That's the reason why the FCC and its international counterparts have to license most frequencies... otherwise there'd be more people wanting to broadcast than useful space and all sorts of jamming situations would result.

Any time a band is released for consumer applications, this almost always happens... somebody tries an application that uses all of it. Eventually, those devices are shunned by the marketplace when they're blamed for causing everything else on the same band not to work...

Re:Yeah! Screw the neighbors!

[Peeet]

Ha, if any of my neighbors did this, I would just be happy that my free internet was finally increasing in bandwidth and signal power.

Re:Yeah! Screw the neighbors!

[misleb]

It doesn't work like that. Your AP still has to recieve a singal from clients... which don't have an amplified signal.

Re:Yeah! Screw the neighbors!

[Anonymous Coward]

Antenna gain is however reciprocal, so a better antenna could still cause havok on neighbors.

Re:As if Wi-Fi space wasn't crowded enough already

[Anonymous Coward]

Matthew has confirmed it, WiFi is dying.

PARENT IS A TROLL! MOD DOWN!

[Anonymous Coward]

The parent is a bunch of random bs thrown together to sound good and get modded up. Mod it down.

No

[Wesley Felter]

The IEEE 802.11 standard uses the 2.4GHz and 5GHz bands.

PARENT IS A REPOST! MOD DOWN!

[Anonymous Coward]

Parent is an anti-slash repost. Mod down. -1 Troll.

Re:As if Wi-Fi space wasn't crowded enough already

[thrillseeker]

I'll take good ol' reliable wires any day. Wireless is overrated.

Well, it's kinda handy when you don't want any, ah, wires.

Re:Use Multiple Channels

[Anonymous Coward]

Yeah, instead of driving a long vehicle with multiple rows, everyone could be in the front seat! Too bad if it makes it difficult for others to change lanes or bypass problems.

Limit the transmit range

[nevek]

The home routers that use this technology will probably have an option to limit the transmitting power (as most do right now) this will allow only the people in the house to use the connection, if the neighbor does pick up the connection, it will be so weak that the people in his house will pick up thier own signal (since it is exponentially stronger)

Re:Limit the transmit range

[bru_master]

I am a user of Cisco, Symbol and proxim products, not much of the home stuff goes onto my network. I normally turn the power settings all of the way down and set the minimum speed of the associating device to 11 MBPS or 5.5 MBPS this would not let devices beyond the 5.5 meg cell associate. I also position the AP away from outside walls and windows so anybody sitting in the parking lot cannot associate at 2 MBPS and try to bust the WEP key. Lets face it there are many persons out there with more time on their hands than the rest of us.

I would hope the netgear and and linksys goodies have power settings because why would you want to blast the person next door with access to your network. There are WEP crack tools out there so if you are running WEP there is still ways to get in,,, even ciscos leap has been reported to have been cracked on slashdot yesterday and that was pretty secure.

Fah. Not worth it.

[Slayk]

As if setting up a wireless network in an apartment wasn't a big enough pain in the ass already, now I've got to worry about the yokel next door hogging all the available channels?

This is going to casue more problems in resedential areas than it will solve.

Valid Uses

[yoshi_mon]

While it's been duely noted that using up more channels could interfere with others who are trying to use 2.4, there are a number of applications I can see that would be useful for this type of setup.

Large old office buildings that arn't wired for ethernet, large warehouses, and people who live on large plots of land.

Yes, if you are living in a typical burb or in the city and try to use one of these you could run into issues with running out of channels. However not everyone lives/works in small areas.

Re:Valid Uses

[LostCluster]

Large old office buildings that arn't wired for ethernet, large warehouses, and people who live on large plots of land.

Common bond: Areas where for the range of WiFi, you control nearlly all of the territory. Therefore, you're sure you're not getting in the way of anybody else because there's nobody else arround.

A densely packed dorm or appartment house is not the place to do that. It's to the point that in 2-family dwellings, the families need to agree on a consumer bandwidth sharing plan between each other so they don't buy devices that'll collide. Something like "You go on channel 3, I'll go on channel 10 for WiFi, and we'll reserve 900MHz for phones so don't get a 2.4GHz one..."

Re:Valid Uses

[Jeff DeMaagd]

With old office buildings, I think it would still be worth wiring even if you wanted people to wander with laptops.

The more people you have on the network, the more of an issue available bandwidth will be. Everyone getting their own dedicated 100mbps wire is better than dozens sharing 108mbps common wireless bandwidth.

It only costed me about $100 worth of materials to connect two computers 140ft away from a switch, and a third one about 50 ft away from same switch. The cost counts metal conduit, metal boxes, plates, wire and ends. That is less than the additional cost of wireless networking hardware, and you don't have to worry about the microwave in the break room screwing everyone up.

Re:As if Wi-Fi space wasn't crowded enough already

[LostCluster]

Yep... but you have to be careful what you're using is right for your application. If you're using WiFi to go accross the room, you should be using Bluetooth.

Sounds like

[ajs318]

This just sounds like a new form of bogarting to me. The whole idea of there ever being multiple channels in the first place was so that everybody would have a chance of finding a free one -- things like this go right against that idea.

If it isn't actually illegal, it's certainly anti-social. But then again, I don't use any wireless kit anyway ..... I need to have a power cable, so I don't mind having a network cable as well.

Re:Sounds like

[LostCluster]

It's not illegal by the FCC because anything goes in 2.4 GHz so long as you don't go over the power limits... there's no bandwidth-footprint limit that keeps you from using everything between the lines.

However, this does violate the IEEE specs for 802.11b and 802.11g. They can claim that they can interoperate with such devices, but they aren't one themselves. Those specs say one channel to a customer so that other applications and networks can exist without being blown off the air.

Two 801.11g networks next to each other can perform perfectly well once they realize to get themselves on non-overlapping channels. Two of these devices next to each other are going to collide left and right and have nowhere to run.

Re:Sounds like

[quantum bit]

It's not illegal by the FCC because anything goes in 2.4 GHz so long as you don't go over the power limits... there's no bandwidth-footprint limit that keeps you from using everything between the lines.

So if my neighbors get one of these I just need something that will broadcast random noise at the maximum allowable power level over the whole 2.4Ghz band, with a directional antenna. Then we'll see how long it takes for them to give up and take it back to the store because it doesn't work.

Re:Sounds like

[ajs318]

It's not illegal by the FCC because anything goes in 2.4 GHz so long as you don't go over the power limits... there's no bandwidth-footprint limit that keeps you from using everything between the lines.

But the FCC is not the only authority regulating the use of the electromagnetic spectrum.

But...

[Anonymous Coward]

... at what cost security?

DLINK does this

[pbrewton]

Doesn't DLINK use this technology today? I think that's how the Xtreme G routers achieve their 108Mbps speed. http://dlink.com/products/?pid=292

Huh?

[blair1q]

If I'm buying a new chipset, I'm buying 802.11g and getting 5X the speed, not just 3X.

Re:Huh?

[engimeer]

All three channels are 802.11g or 802.11b or any combination thereof. Each channel is independent and can be configured by software to be a/b or g ......although the a flavor requires a different RF chip (Engim has both a 2.4 GHz transceiver chip and a 5.2 GHz transceiver chip each capable of handling 3 channels.

What they are really talking about

[ZPO]

Based on reading the article they are talking about a software defined radio (SDR) which is capable of operating discrete carriers and user communities on each of the 3 non-overlapping channels. They are not talking about bonding all 3 channels into a single data link.

Based on the article the chipset will be *capable* of using all 3 non-overlapping 2.4Ghz ISM channels. That will allow the associated users to be split across the 3 channels rather than all on a single channel and competing for access to the channel.

The same tradeoffs that drive WLAN design today will still exist. Its not a panacea, but it does add new possibilities to the engineer's set of available solutions.

By opening up the front end of the radio they can look at the whole band and do some very interesting noise reduction techniques. This is alluded to in the article, but I think its the most promising part of the chipset. The ability to identify and reduce the affects of wideband noise will got a long way to improving reception of WLAN signals....

tradeoff

[l33t-gu3lph1t3]

While combining channels may be a somewhat decent idea, it has a serious drawback: you lose your usable channels! I believe that maximum feasible number of users on any one access point is about 50, right? That's on channels 1,6,11. Sure you get more speed by using just one channel and sharing the resources of all 3, but hell, now only about 17 people can use the network!

Re:tradeoff

[wankledot]

That depends on the access point, Cisco APs (which is what I work with at work) support hundreds and hundreds of connections.

Re:tradeoff

[l33t-gu3lph1t3]

I work with Cisco APs as well, in fact we just installed our wireless network. I was told by the site surveyor that 50 connections per AP was a realistic maximum given 802.11B. This seems to be contradictory to what you're telling me...so which is more accurate?

Re:tradeoff

[wankledot]

50 is a great number to design around, because any more than that you will be cut down to a trickle of bandwidth for each one. The access points technically support quite a few more simultanous connections than that, but no one is going to suggest that you design a newwork for a thousand clients per AP. There might be some odd situation where you need more than a hundred clients per AP for some low-bandwidth use (can't think of one, maybe like, a zillion iPaqs in a big room with one AP.. who knows.

IOW, you could have a lot more than 50, but you really shouldn't.

Re:tradeoff

[l33t-gu3lph1t3]

ah ok. We have classrooms and conference rooms that seat 170-200 and will need to support 1/2 that in wireless connections. Should be interesting then, given what you've told me.

Did anyone else first read the headline...

[Micah]

... "Use multiple camels for faster wireless networking" ??? *rolls eyes*

Re:Did anyone else first read the headline...

[Anonymous Coward]

No. Shut up.

I can see the FCC loving this.

[Halvard]

The licence that 802.11, A, B, G, etc. falls under says that if you inferfere (and you are discovered to be the culprit), you can't use it. I'm paraphrasing but I suspect that if you saturate the bandwidth available in the frequency and you get outed, then you'd have to stop using at least all the frequencies or the offending radios.

Re:I can see the FCC loving this.

[engimeer]

Halvard you ar mistaken. actually the 2.4 GHz to 2.484 GHz band is unlicensed by the FCC. This means that any device can use this band as long as the transmitted power is below 1 watt AND the emissions in the restricted bands (a set of defined freqeuncy bands) is lower than the prescribed power levels (see FCC rules part 15) Any device using the 2.4 GHz to 2.484 GHz band MUST accept interference from any other device using this band. It is up to the people that are setting up the equipment to make sure it works without interfering with existing equiment. this mean the FCC will not be policing the usage of these frequencies. once you are outed you will have to work it out with your neighbors your self.

Re:As if Wi-Fi space wasn't crowded enough already

[misleb]

Dying? No. Getting crowded and more difficult to implement reliably? Yes. What are you going to do when your neighbor decides it woudl be useful to take up all non-overlapping channels? Sue them? You have to track them down first. I tried implementing wireless for a client and they couldn't keep it running because some bozo in their building had a WAP that was channel hopping. Every time we found a free channel (there was 1 other wireless users in the building also), it'd get clobbered a few hours later.

-matthew

Department

[BandwidthHog]

From, uhh, *what* department?

Ahem.

Re:Department

[BandwidthHog]

Holy shit people, who did I piss off with that inane comment to earn two Overrated mods? I mean, c'mon, some doofus actually burned a mod point on a comment already at 0? Wow. Must be the sig.

Re:Department

[michaelhood]

Must be. And now to burn my karma..
What do you expect to happen when you post something as mindless as that sig with no explanation whatsoever? Perhaps REAL Karma will come back around, and you'll be hit by a truck. Contineo contigi.

Re:Department

[BandwidthHog]

Well, the post was the post, the sig is just a sig. But if you'd like I'll gladly explain it. It is meant to remind people that you shouldn't do things that adversely impact the lives of others based on your superstitions. At least that's my take on it, I didn't come up with it (although I wish I had).

Re:Department

[michaelhood]

I admire that you had the courage to respond to that. And your explanation actually made sense, but the original sig is still vague. You can expect people to confuse it. Maybe you should link it to an explanation page ;) Good luck.

No, it's different

[Anonymous Coward]

It's Super G developed by Atheros used in the D-Link products. One of the thing it uses is channel bonding centered on channel 6, but it doesn't take up all the channels. Broadcom claimed that this had the potential to interfere with the other channels to a greater degree than normal signals.

Re:No, it's different

[vedli]

I have a 3Com wi-fi network card which claims to have a nitro setting. When using it with my 3Com router it appears to take up more than one channel. Is this the case?

+1 Stateing the Obvious

[Anonymous Coward]

Good job! I think that was the point of his whole post!

Dlink has a similar idea

[FigWig]

Dlink's AirExtreme G products advertise speeds up to 108 Mbps. Their literature implies that they use two wireless channels to achieve this speed.

I have their wireless card & router, but can't get the 108 speed because of some legacy b adapters in the network. The G speeds are quite nice - even though 802.11b's theoretical speed is higher than my DSL bandwidth, it's actual performance was quite dissapointing.

Re:Dlink has a similar idea

[PCM2]

The G speeds are quite nice - even though 802.11b's theoretical speed is higher than my DSL bandwidth, it's actual performance was quite dissapointing.

Heh. You know, it wasn't so long ago that pretty much nobody's LAN had more bandwidth than 10Mbit...

Overlap affects B and G, Not A or H

[Erik_]

The 2.4Ghz bandwidth used by 802.11b and 802.11g have overlaps. The 5Ghz used by 802.11a and upcoming 802.11h (802.11a with Power Management) have non overlapping channels.

802.11g => ~32Mbps throughtput x 3 non-overlapping channels = ~90Mbps total usable bandwidth
802.11a => ~25Mbps throughput x 12 non-overlapping channels = ~300Mbps total usable bandwidth
802.11h => ~25Mbps throughput x 24 non-overlapping channels (due to better pwr mgmt) = ~600Mbps total usable bandwidth

Re:Overlap affects B and G, Not A or H

[MoFoQ]

maybe the point was to be able to use all (A, B, G, etc.) simutaneously (aka, in parallel when/where possible) in one affordable package.

Legal?

[panxerox]

As all rf transmission systems are highly regulated and this must have an fcc licsence, does the liscence cover this kind of usage?

Re:Legal?

[BoltInMyEar]

There are FCC regulations, but none that pertain to channel usage in the case of 802.11 wireless devices. The regulations deal with maximum power levels and what portion of the RF spectrum may be used. There are no regulations pertaining to who may use which channels. If that weren't the case, anyone setting up an AP (or for that matter, using a 2.4GHz cordless phone) would need the equivalent of a ham radio operator's license.

Antisocial practices like hogging all the channels might encourage the FCC to start licensing whatever next-gen wireless devices come along, and I'm not so sure that's a good thing.

Not quite.

[jvonk]

A connection is centered on a channel. If you remember your basic signals class, the bandwidth of the connection is dependent upon the width of the signal. Therefore, the actual bandwidth (in the RF sense) consumed by a connection is dependent upon the bandwidth (in the networking sense) of the link. Nyquist theorem means that an 11 Mbps link consumes a nominal 22 MHz (11 MHz on either side of the 'center' frequency, aka. 'channel')

You can read this for a little more info.

MOD DOWN - Stolen post

[Anonymous Coward]

What a funny coincidence: _avs_007 seems to have made exactly the same post in this thread last year. What're the odds, eh?

Re:As if Wi-Fi space wasn't crowded enough already

[System.out.println()]

Unless of course, you want a faster speed. By my understanding Bluetooth is about 1/10 the speed of wifi (unless I heard wrong.) And that's just 802.11b, not g.

Re:As if Wi-Fi space wasn't crowded enough already

[Gyorg_Lavode]

Well gee, I guess I could just run out and buy that bluetooth AP, bluetooth pcmcia card, and blue tooth bridge (well, 2 devices of course), to replace the wireless stuff I have in my apartment.

Except that .11 is cheap and easy to get/ impliment while bluetooth is almost nonexistant.

Re:As if Wi-Fi space wasn't crowded enough already

[Anonymous Coward]

Last I checked, you can turn down the power on most 802.11 devices. Even if you couldn't, you could cover the antenna with some random junk.

Increasing throughput and...

[PetWolverine]

The Engim chipset can 'see' all 11 at once, and can use the three non-overlapping ones (1, 6 and 11) in parallel, increasing total throughput and ...and destroying any and all other wireless networks within range. Good job, guys! To paraphrase Hobbes (as in "Calvin and", not Thomas), maybe someday we can make wireless a complete impediment to networking.

(Original: "Maybe someday we can make language a complete impediment to understanding." in response to Calvin's "verbing" words.)

same effect using two wifi cards?

[stiller]

Maybe I'm missing something, but could you not achieve the same effect by whacking in two wifi cards and using some loadbalancing scheme in software? I don't see why this would be any slower than a hardware implemented solution, I think the CPU cycles spent are hardly the bottleneck here. Having said that, I think this is a silly solution that only wrecks the whole shared spectrum idea of wifi. If I were a wlan network admin, I would find (packet analyze) and block these guys. (not applicable on public networks ofcourse).

Re:same effect using two wifi cards?

[Anonymous Coward]

I could see this used within a building suitably equipped to block the signals from extending outside of the building. And if you are in an area where there is no other wifi, say out in the middle of nowhere, there should be no problem utilizing this technique. But I agree, in areas already saturated with wifi traffic, this can't be a good idea. But I'd be surprised if the chipset didn't revert to legacy single-channel mode if the necessary channels are all in use.

scanning networks

[Gyorg_Lavode]

Would a card like this, integrated with airsnort and appropriate drivers allow quicker characterization of the network traffic in an area?

ummmm.

[bobdole369]

Good lord talk about interference. The FCC ought to be having a heart attack. Imagine if Ford designed a new SUV that took up three lanes of traffic...

Re:ummmm.

[tonywong]

They did. It's called the Excursion.

Re:As if Wi-Fi space wasn't crowded enough already

[Anonymous Coward]

If there's too many other people, chances are a few of them as WEP dissabled, instead of further crowding the space with your router, just use their free internet access. That's what I do.

Misunderstanding of Engim

[arrianus]

What Engim is doing is actually a good bit more sophisticated than any of the Slashdot posts imply. When you transmit, you usually have two types of bandwidth: how much bandwidth you are using, and how much you are interfering with. For instance, a simple AM broadcast will require maybe 8KHz of the spectrum on which it actually transmits data. Since transmitters are imperfect, however, it may actually interfer with transmitters on, say, 20KHz of spectrum.

As a result, if you're in a big company, and set up 3 off-the-shelf 802.11b access points, on 3 different theoretically non-overlapping bands, you'll still get something on the order of, maybe, 1.6x the bandwidth you'd get with one.

What Engim does is it has an insanely fast ADC/DAC front-end, that grabs the entire 802.11b/g spectrum, including all the bands. Then, they have a fancy DSP that looks at the bands together, figures out how they interfere with each other, and sorts them out. As a result, in a theoretical world, where only notebooks were transmitting to the access point, they would have 3x the bandwidth. They do fancy transmitting techniques, so that notebooks on all 3 bands can hear at the same time. So if the wireless access point was transmitting, and all the notebooks receiving, they would, again, have 3x the bandwidth.

The problem is that notebooks don't have this sort of technology, so when they transmit, they cause interference for other notebooks. If the Engim WAP transmits on band 1 to notebook A, and notebook B transmits on band 2 at the same time, the transmission from notebook B may interfere with that from the WAP. As a result, in practice, it's a little less than 3x the bandwidth, but not a heck of a lot less. They try to juggle notebooks between bands, based on location, so this doesn't happen, but it doesn't really work too well.

The technology they have is wicked cool, actually. For those worrying about interference -- it's really not a problem. First of all, this isn't for personal WAPs, but for $1000 access points you'd see on an IBM or Microsoft campus. They won't be going in apartments any time soon. You need a minimum of 3 very expensive chips for a single WAP (RF front-end, ADC/DAC, and DSP). Those places don't tolorate employees setting up their own WAPs anyways.

Second, you still have the remaining bands. The way 802.11 works, with the interference issues described above, if I set up a WAP, and my neighbor sets up a WAP, we will be interfering. We'll both have wireless networks, but both with reduced bandwidth. You can still set up your own WAP on any of the remaining bands, and it'll work -- it's just that if you try to send a packet at the same moment as the Engim network, you'll get a collision and retransmit. This is what happens anyways. 802.11 was never designed to have many, non-interfering bands. It was designed to have many, interfering, overlapping networks, with packet collisions. By design, the total bandwidth of 5 overlapping networks, in the same area, is the same as if there was only one. Each network gets 1/5 of the bandwidth then. This is the exact issue Engim technology is meant to address.

In terms of cell phones, etc. my impression is that the Engim technology was actually smart enough to look for "interference sources" and try to pick bands around them. This last bit is from an Engim PowerPoint slide, so I'm not sure if it's actually implemented or vaporware.

Noooooooooo!

[Jahf]

This will destroy wireless ISP communities.

I already have only -2- channels that I can reliably use in my house without interference. Every other channel is in use for ISP access in our community or gets interference from cordless phones and microwaves.

If you want more throughput, use different frequencies. Even if they are close to 802.11b/g that is better than going into the already established spectrum.

Yes, I know that this is not mandated or regulated space, so there is not much I can do to enforce my needs. However unregulated waves only work if people make an effort to play well together.

Re:Noooooooooo!

[hyc]

If you're getting interference from microwave ovens then it's time to call the FCC and have it stopped. A leaky microwave oven is a serious health hazard.

I've got a scanner that receives up in the 2.4GHz range, and I've swept thru it a couple of times looking for signal while my microwave was operating - not a peep, even at 3 inches away.

Re:Noooooooooo!

[Jahf]

I can't do much about the microwave interference.

My wireless ISP antenna is a point-to-point antenna pointing at a location about 1.2 miles away.

Unfortunately there are 4 restaurants -directly- in a 2D line (slightly lower than the AP in a 3D line, but close enough). Interference skyrockets from 11:30am - 2:30pm and 5pm - 8pm ... prime food times.

Because of this, the ISP connection can only successfully use a couple of the frequencies that are not as badly hit by the microwaves.

Since this is a point-to-point reception issue, and not a broadcast style reception problem, the amount of interference from a commercial microwave doesn't have to be nearly so much as it would to inject trouble as a wide signal.

In and of itself, not a big problem for me, just one of the issues that combine to make 802.11b verrrrry crowded up here.

The fact that there are 2 competitors to my ISP also in a direct line for my antenna doesn't help, but they tend to use different parts of the 11 channel spectrum so as long as no one pops up yet another AP I'm ok there.

FWIW, I've found that my Siemens 8825 doesn't give significant 802.11b interference, but my old Panasonic phone would completely destroy channel 1.

Also FWIW, while my very new microwave doesn't interfere with my 802.11b, it does cause crackles on my Siemens phone if I am standing with the microwave between me and the base station, assuming I am at least 40' from the station.

Point? Not much this far down, just posting it in case someone finds it as a search I guess.

Re:COPS

[bru_master]

why does every meth lab have an owner that is 50 pounds overweight or 50 pounds under weight.

No problem

[Anonymous Coward]

Translation: They're covering the entire 2.4 GHz band, and making no appoligies to anybody else who hoped to use it near their systems. Any 2.4 GHz phones will have nowhere to hide.

There's no need to worry. Thanks to Slashdot, we know that radio spectrum interference is a myth.

*Cough Cough*

[Anonymous Coward]

Vivato?

Bye Bye Spectrum

[matth]

Yeah,
that's right now we don't have ANY spectrum left because joe smith, mary smith, and dan smith (who are all my neighbors) are using their 3 channeled access points at the same time to download music off kazaa and I'm left with no good open channels.. woohoo! great management!

Durrr...

[buddha42]

Hay guys, If I fill up all the slots on this FTP server I can leech faster!

Better go post this to slashdot, its an amazing discovery!

Quite not quite

[rfmobile]

Your nyquist analogy assumes a simple binary symbol set (ie. "1" and "0"). The signal bandwidth is a function of the symbol rate. If your symbol set is larger than just two symbols (say 8, or 16, or ...), then you can deliver more bits per symbol. That's why "G" delivers more data bandwidth than "B" in the confines of the same channel signal bandwidth.

-rick

Re:Quite not quite

[jvonk]

I realized it was a simplification when I posted; I also neglected to add protocol overhead and to substitute Shannon's theorem (since RF isn't really a noiseless channel in this case, now is it?)

Using the simplifications of Nyquist theorem and a binary symbol set was a reasonable approach to briefly explain the issue, especially since 802.11b uses a binary symbol set.

Ancient News

[sjvn]

And why use three when you can use four?

http://www.extremetech.com/print_article/0,1583, a= 33684,00.asp

Oh, and of course, the real world reason this isn't such a hot idea is that you can only use multiple channels to boost bandwidth only in WLAN environments where you control where the APs go so you don't have multiple APs interferring with each other.

Steven

Wideband WiFi using channels 1, 6 and 11

[Anonymous Coward]

A limit of that technique is that the total output power is still limited by Part 15 regs, so when you use 3 channels, the AP should run each channel at 1/3 of the power, or run afoul of FCC regulations.
Guess which happens?

Re:As if Wi-Fi space wasn't crowded enough already

[Anonymous Coward]

Prediction

In a few years time no-one will be using wireless because it will be too congested because too many people are using it.

Re:As if Wi-Fi space wasn't crowded enough already

[misleb]

Heh, not only do people not use WEP, but they usually leave the default password for the device. Unfortunately, if you have a home LAN and/or a business, you can't rely on someone else's wireless.
(not that you should be relying on wireless at all, but that is a different story)

WRONG

[Anonymous Coward]

802.11a uses the 5 GHz UNII band.

In a word: 'No'

[Anonymous Coward]

Check it: this is a limitation of the physical medium. For 802.11b (for instance), every node connected to the AP on a given channel shares the 11 Mbps 'pipe'. Two cards would get you redundancy, but each one could only have a maximum of 5.5 Mbps.

You could, however, connect one card to one AP on one channel and another card to a different AP on a channel that was 5 channels above or below. Oh, wait, that is what this product does!

Before you ask, this is a fundamental physical limitation of using RF. As St. Claude (Shannon) the Divine might have said, "it's not just a good idea, it's a physical law!"

Re:As if Wi-Fi space wasn't crowded enough already

[vedli]

I've just installed a wireless network in my house and I love it. I love being able to walk around and surf the web without the need to trail cables everywhere. I think you're wrong about the demise of wireless networking. I think its the way forward, even if not in its current wi-fi form.

my solution

[pensivemusic]

would be to watch the packets and buffer them to a holding state if the system was 'busy' with whatever. when the system was clear or had a lull, then the packets in the holding state would be allowed to proceed. this transmit collision thing takes up a lot of time. not everything needs a go or no go status... perhaps a later go status is workable?

Using three channels at once...

[reverb]

Suppose you had a wireless router in your house and you wanted to have computers (or something) in your house on channels 1 6 and 11. You've got two options, as far as I can tell from rudimentry networking class: Either set your router to time division multiplex (process 1 for T seconds, process 6 for T seconds, process 11 for T seconds, repeat) or get three access points and plug them into a hub/rounter, set one to work on 1, one to work on 6, one to work on 11. What these guys do seems like the equivalent of this last option in one box.
(http://www.engim.com/products_technology.ht ml)

Regarding wireless phones and Wi-Fi: you're going to run into problems no matter what if you try to operate on three channels at once. Simply because an access point can operate on three channels at once doesn't mean that it will pump out crap regardless of whether or not you're using those channels. So the notion of these guys monopolizing the 2.4GHz band against your will seems far-fetched...I think your microwave screwing up your WLAN is more of a worry.