Slashdot Mirror
FCC Approves 802.11b Phased Array
n6zfx writes "802.11b Networking News is reporting that vivato received FCC approval for the 802.11b AP that has a range of 4 miles... This was discussed recently here on slashdot -- There were comments that it might not be totally legal. Hopefully, this paves the way for more WISPs, bigger hotspots, and replacement of outdated wireless technology that seemed to be the only competitor to DSL and tv-cable for the last mile."
With a long range like that I guess your brain will be pretty fried if you sit close to the AP, no?
Martin
This will be especially relevant for Bandwidth co-ops.
The biggest obstacle to creating a co-op is having enough potential subscribers to convince the telcos that it will be worth their while to run the dry pairs the "last mile" from the DSL POPs to the houses. I am guessing that this technology will begin to allow metropolitan bandwidth co-ops to have an effective solution outside of the telco's control. Please, oh please, let broadband not suck forever.
Vivato's bases reach groups of users on existing laptops and other computers, with an operating range up to 7 kilometers outdoors, the company claims. Software controlling the antennas detects Wi-Fi clients in the area and adjusts the signal across the array many times per second.
Which is great, except when they overbook in order to maximize revenue, much like cell phone companies. Then we have spotty, intermittent coverage serving only a percentage of paying customers, as the system struggles to keep up.
Yay technology!
The theory of relativity doesn't work right in Arkansas.
A company in Sweden conducted tests with a stratospheric balloon. They broke 300 km (187+ miles).
Not entirely salient, but a reminder that there's more than one way to skin a cat.
So, if the Starbucks a few blocks over installs this, is it going to stomp all over my home network? I mean a WiFi hotspot with a 4 mile radius is great, but hopefully wouldn't affect home users. That'd be like some new cellular tower killing my cordless phone...certainly not appreciated.
"Where quality is like a dead stinking rat - you just can't miss it."
That's a lot of Pringles cans.
...until Pink Floyd uses them in concert.
I'll form my OWN solar system! With blackjack! And hookers!
Interesting...... Gives rise to lots of new avenues for hacking too. Imagine to not have to be PHYSICALLY wired in. Instead... use your laptop to connect to your target server's airport and VOILA! Maybe companies will sheild their office complexes, so that a guy sitting outside the fence can't mess around with their data.
Exciting possibities....
|/________
|\A|ALYS|
I could have sworn that the last time I heard "phased array" and "4-mile radius" together in one sentence something in some movie blew up.
I need an alternative source of domain packets!
The quality of 802.11b security implies the need to lock down the bandwidth with something.
Could this turn into the killer app for IPv6/IPSEC?
Well, Sprint Broadband works, it delivers >3Mbps, it's fairly easy to install, and it costs $50/mo. And I doubt it's a money losing venture, otherwise they'd have discontinued the service entirely rather than just not taking new signups.
If companies will compete with Sprint broadband using Vivato technology, that would be great. But with the Vivato APs being released in 2003, I think it's at least another year away until you are going to see viable commercial broadband services based on it springing up.
I'm afraid killing people takes precendence over informing them. The Pentagon reports that wi-fi networks interfere with their radar and further rollout of the technology must be curtailed. Read this article.
<a href="http://www.joblessjimmy.com">Work is dumb and so is Jobless Jimmy.</a>
I am all for the propagation of this technology. I live in an area with no broadband access whatsoever . . . .just don't put the radiating tower in my backyard . . .my kids are weird enough without growing extra appendages
4 miles? That's all fine and dandy, but think of the implications aside from being able to connect in "pocketed" areas.
Too many "off-limits" zones in the suburbs of major cities for this to be any good. Considering the fact that upwards of %80 of the people that'd benefit from this live in such suburbs. PD's, FD's, Hospitals, etc. are all considered to be zones absolutely off limits to any such interference this would cause (suburbs are totally PACKED with these, There are 3 PD's and 2 FD's, as well as 2 Hospitals within a 4 mile radius of my house). That's FCC regulation that's been around since the '30s, and they're sure as hell not going to change them now.
Given the method they'd have to use to make sure they aren't broadcasting in that area, you end up with 1 or 2 degree swaths of no service areas eminating from the tower. May not sound big, but after a mile or so it gets to be the width of a city block.
I'm all for this, but a better solution would be to use smaller and cheaper arrays. Just find a way to lower the latency and it'd be even better.
Of all the Universal Constants, here's one I know: Nice guys finish last
802.11 has been shown [1] to be completely insecure... have these security issues been fixed? From my reading of the paper, all that really needed to be done to fix most of the issues was to switch from OFB mode to CBC or CFB [1] Nikita Boristov, Ian Goldberg, David Wagner. Intercepting Mobile Communications: The Insecurity of 802.11. SIGMOBILE 2001. http://www.berkeley.edu/isaac/mobicom.pdf
Given the qualifications and history of Ken Biba listed in the article
Biba started in security and networking R&D 30 years ago with Mitre Corp. and was a member of the Advanced Research Projects Agency Transmission Control Protocol (TCP) Working Group
I wonder if he is the same Ken Biba that worked on/devised Mandatory Access Control (MAC) and the Biba Integrity Model.
There is a good description of MAC here, and an explanation of the Biba Integrity Model here.
I want to drag this out as long as possible. Bring me my protractor.
Does my stove have WiFi-support?!? Woohoo!
An AMPS phone may be limited to 600 mW in the systems in Australia, but the actual limit on a Power Class 1 Phone is 5 watts. That is one of the reasons that replacing the AMPS system with (CDMA|TDMA) systems in the US has been very slow - a Class 1 phone can contact a base station many tens of miles away, which is IMPORTANT in much of the US - when you are in western Kansas, Nebraska, Wyoming, Montana, Utah ... you get the point.
That was part of why the old phones where so large - a 5 watt 100% duty cycle power amp isn't tiny. (the other reason was that since AMPS requires the phone to transmit and receive at the same time, the phone had to have an RF duplexer in it - not a small item, even at 800MHz. TDMA phones don't transmit and receive at the same time, hence they don't need the duplexer).
That's one of the reasons I tell people to look for the old phones at garage sales - get the phone and you have a dandy 911 phone - you WILL get a connection!
www.eFax.com are spammers
So how exactly do people with pie in the sky Wi-Fi plans intend to overcome 802.11b's inherent scalability problems? How many people can one AP REALLY serve?
From my experience I'd say that answer to that question is not very many. Having more than a couple people on a single AP is a recipe for pain and suffering. As the number of users on an AP increases so does the chances of packet collisions. As collisions increase the viability of the network decreases and you eventually reach a collapsing point where the network is unusable. A corollary to that rule then would be the larger your coverage area the higher a chance of collisions and thus a higher chance of the network collapsing.
You run into a similar problem with 802.3 which is solved by switching the network. With a wireless network you don't have the ability to add a switch in the middle of the network to keep the number of collisions down to a minimum. You're only got a bunch of nodes waiting their turn to talk. Switching channels isn't an option because APs can only serve particular channels.
With a coverage area of four miles then, the number of potential collisions on a channel is pretty high because your entire customer base could be in that four mile coverage area. Sweeping a broadbast between different nodes doesn't do much good on their end where all the static from other connections is an issue. On current networks you've got a small number of users because your coverage area is pretty small so problems aren't evident. You don't have problems on a wired network with only a 5 port hub either.
I'm a loner Dottie, a Rebel.
Makes sense that you can build a big-ass AP that will provide a large 802.11 blanket, but how is my laptop's little antenna going to talk back to it?
indierock / punkrock band photos and more... http://www.digitaldefection.net
The Terminator: The .45 Long Slide, with laser sighting.
Pawn Shop Clerk: These are brand new; we just got these in. That's a good gun. Just touch the trigger, the beam comes on and you put the red dot where you want the bullet to go. You can't miss. Anything else?
The Terminator: 802.11b Phased Array rifle in the forty watt range.
Pawn Shop Clerk: Hey, just what you see, pal.
If your Wi-Fi network extends 4 miles, then the terrorists have already won.
I've been awaiting the resurrection of Ricochet in Orange County, CA, but with a four-mile radius I could (using company money, of course--I doubt this new AP will be cheap) set one up at home and at the corporate office and have the effect I try to achieve using (past tense) Ricochet and (present tense) T-Mobile HotSpots. That effect is to change my environment to either a nearby park, pub or (what's a another p-word? It's early) other place while I work. Within a couple miles of both home and office I have parks, lakes, pubs, restaurants. . .just not the beach (maybe I still will need Ricochet!).
-- @rjamestaylor on Ello
I don't care about all these cool _wide_ _open_ _land_ solutions!
What about all the people who can't even see their neighbor's house? I want to set up a WISP in my neighborhood, but I have no direct line of site to anybody.
---- It puts the lotion on its skin or else it gets the hose again. It does this whenever it's told.
Whoa... Every time I hear that term it's on Star Trek and in regards to some huge weapon of mass destruction.
Trolling is a art,
Please guys, this techonology is NOT about splattering megawatts all over town!
It is about aiming a low power beam in the right direction using a smart antenna AND that same smart antenna is a better listener.
It's a high-tech equivalent of a parabolic antenna and it is adjusted to radiate the same power at a distance as a normal omnidiretional antenna would do. That's what the FCC require in order to approve an antenna.
It's a common mistake to think that range=power. Note that this is a two way operation.
You also have to be able to hear the other guy, right? That takes good listening skills = a directional antenna.
Now if Only I can calibrate the deflector dish to use the dilithium crystals to create a Tachyon pulse...
Where is Spock when you need him?
I am all for the propagation of this technology. I live in an area with no broadband access whatsoever . . . .just don't put the radiating tower in my backyard . . .my kids are weird enough without growing extra appendages
I understand that you are trying to be funny, but I see sooooooo much cell tower ignorance at zoning hearings.
First of all, people (including zoning officials) do not understand that radiation levels are not something that can keep out cell towers. That is an area which has been pre-empted by federal law.
Second, they do not understand that cell phone radiation is not ionizing radiation. It cannot break chemical bonds and cause genetic mutations. It could cook you if you stood close enough and it broadcast at a high enough power, but it cannot cause cancerous changes. These people hear "radiation" and think "Godzilla" not "reading lamp". It's just blatant science ignorance.
GF.
Lots of petrified grits
Actually, the FCC doesn't limit raw power, it limits power per solid angle steradian (actually, it's usually max power/square area at a certain distance -- effectively the same, but no confusion over near-field effects of the antenna). Just like using a magnifying glass to concentrate sunlight, it can be just as dangerous to concentrate RF power - and the FCC knows this.
Still, the increased bandwidth due to multiple beams will be very helpful in overcrowded environments.
HIV Crosses Species Barrier... into Muppets
Dear Tiger Direct,
Do you offer volume discounts for 802.11 equipment? We are interested in many hundreds of thousands of these and will gladly pay in counterfit US dolars, oil or gold.
Sincerely, your friend.
General A. Henchman
Iraqui National Air Defense
Bagdad, Iraq.
Friends don't help friends install M$ junk.
The only answer is to use an easy to customize, stable and relativly secure operating system and lock it down. This will lower the chances of your machine being owned by someone else who will then use it to search for content of interest, store mp3s, movies and kiddie porn, or to harrass others, yet not throw out the whole purpose and promisse of the internet: the sharing of information and computing resources.
I'm very very tired of people transfering their eXPerience with worm, virus, hole plauged operating systems to "security" of the internet. Not every machine in the world is brain dead enough to run an email client as root and automatically execute attatchments. Some people use freely available secure communications packages like OpenSSH. Get a clue people, especially you, Uncle Sam.
Friends don't help friends install M$ junk.
My understanding is that the 802.11b RF bandwidth is currently limited by the 802.11b protocol.
0 0.asp
jeff
However... a new variation of 802.11 -- 802.11g (yes "g", not "a") will increase the data rate to 54mbps. 802.11g is also supposed to be dual mode and support 802.11b clients.
(The link above is http://www.extremetech.com/article2/0,3973,21749,
It turns out that if one of the antennas in the link is high-gain, then it is high-gain on transmit *and* receive.
Consider cell phones.. the phone has this tiny little antenna, but the cell site has a big honking high gain antenna that concentrates the RF in a pancake, and in some case in just more-or-less one direction -- e.g. towards the highway.
Hence, this thing works with standard laptop cards. Pretty neat, eh? jeff
It's shocking that the new administration is following the greedy, ignorant policy of it's predecesor. If such services flop, those who opposed the specturm auctions can say, "I told you so," and that will be that. It's not like the telecomunications has been a stable source of employment for most of the people working there. If the government forgives the auction debts, it will ammount to a huge bail out of big corporate interests. That's bad because it give an advantage to those who bid irresponsibly and continues the ineficient specturm use but at least it will provide service to people at something closer to its cost. If the government legislates 802.11 out of practicality, it will be a huge scandal as the only reason will be to prevent new entrants from ruining these silly third generation services. Yet this third option is the one that keeps comming up. Keeping the public from building their own communications networks, which are technically possible, ammounts to a denial of first amendment free speech rights.
Bandwith scarcity is a lie and services that operate on that principle, metering out kilobytes of data, are a rape.
Friends don't help friends install M$ junk.
Try setting the antea up on top of the tree. It's a free no paint needed tower.
Friends don't help friends install M$ junk.
Name calling is nice, thanks asshole.
I'll bet you never even read the paper I cited.
You might try a valid link to something that's not a huge pdf file. Your link did not work, and I don't like multi megabyte pfs where text can explain the concept.
I don't know why I even bother responding to your drivel, but still...
I know why, let's look and see.
802.11 was designed to provide confidentialty, access control and data integrity. And the paper cited demonstrates that neither of the three are achieved (in very practical attacks... not something involving million-dollar machines)
Aha, you respond because you are a troll. That's not the stated goal of 802.11, now is it? Would you mind responding to the fact that all communications are insecure? It's all very nice of you to call me an idiot, but it would be better if you informed me. As I see things now, you don't need million dollar equipment to tap a phone line, a cable, listen to microwave tower transmisions or most other forms of current communications. None of these forms of snooping takes much more effort than setting up a 802.11 bug. Others with larger budgets can spy on stand alone machines, but even there, I doubt that off the shelf light analysis equipment costs millions. You could hire a competent engineer to build one for you for $50,000 in a year plus a few equipment costs. Encrypted communicatins over 802.11 works as well as encrypted communications anywhere else.
Friends don't help friends install M$ junk.
Pringles Can Antennas !!
or maybe these much nicer looking clones from DLink.
ELiTeUI Out.
I would like to see a better explanation for how clients can talk to the AP over many kilometers. Just by the AP having a "big ass antenna" won't cut it, since by then, the received signal is weak, and amplifying it (say, 14 dB or more via an antenna) will amplify noise as well.
Rough estimates:
30 mW transmission like in Orinoco cards(100 mW being peak) = just under 15 dBm.
Losses in free space, assuming Line of Sight, are 106.5 dB for 2 km.
So, signal is down below -90 dBm. At this point, signal to noise ratio will kill you, regardless of ANY gain from the receiver at the AP.
Peace
Sprint uses an MMDS network, running in LICENSED spectrum. This phased array runs 802.11b in 2.4Ghz unlicensed. I operate a 802.11b based fixed wireless ISP, and while fine for a small markets, it is NOT the answer in crowded urban centers. Or even large suburbs for that matter. Any Joe Sixpack with a Linksys WAP11, an omni, and a big amp could potentially take the network down. Since MMDS is LICENSED spectrum, you can face fines from the FCC for operating in those bands without the license. The equipment cannot be purchased at Circuit City, so it is less likely to be snooped like 802.11b, or interfered with or stolen. The amount of bandwidth available in the MMDS bands is also WAY more than 802.11b provides. I could go on and on about how 802.11b is NOT THE SOLUTION FOR WISPs, and how MMDS IS, but I will leave that for another day. Bottom line, MMDS fixed wireless is NOT outdated, 802.11b is.
If you can't figure out my address, just drop me an e-mail and I will explain.
That has nothing to do with phased antennas arrays. A phased array has more than one antenna. When you use multiple antennas your bandwith goes up whatever protocol you use. The trick is that phased array antennas are all in (nearly) the same spot and cooperate in a sophisticated manner.
-
- - You can't take something off the Internet! That's like trying to take pee out of a swimming pool.
Antennae on trees tend to sway quite a bit and if you're dealing with directional ones, its not going to work.
- Michael T. Babcock (Yes, I blog)
T
---- It puts the lotion on its skin or else it gets the hose again. It does this whenever it's told.
If the designers of X-window built cars, there would be no fewer than five
steering wheels hidden about the cockpit, none of which followed the same
prinicples -- but you'd be able to shift gears with your car stereo. Useful
feature, that.
-- From the programming notebooks of a heretic, 1990.
- this post brought to you by the Automated Last Post Generator...